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INTRODUCTION. Within the past ten years the fruit-growing industry in the States of Washington, Oregon, and Idaho has developed very rapidly. With the possible exception of prunes, the greater part of the product is shipped as fresh fruit to Eastern markets, where it has already won a high reputation for quality. Along with this rapid development of the industry there has been a much more rapid increase in the damage caused by insects and dis- eases. Ten years ago there was little or no need to fight orchard pests, as the injury caused by them was scarcely appreciable. At the present time, at least in the older sections, the fruit grower is com- pelled to combat insects or fungi or both, in order to grow marketable crops. This marked change coming in so short a time, and in many cases involving serious loss, has naturally had a discouraging effect. Ina few instances this discouragement has even led to the digging up of orchards. The increase in the amount of damage by orchard enemies has been the more depressing because the idea had gained considerable credence that the previous immunity from such loss was due to some special peculiarity of the soil or climate or both. Unfortunately this idea still prevails in sections where, for some reason or other, pests have not yet become a serious factor. At one time, when western Oregon apples were justly famous, the growers said: ‘‘ We will never have wermy apples here because the climate is so moist.” In the warm interior valleys orchardists now claim that fungous diseases will never be a menace because the climate is too hot and dry; and upon the inte- rior uplands their competitors say that no insect or fungous enemy need ever be feared because of the-winds and the cool nights. In all this there is a somewhat labored effort to consider as proven what is at best a hope. The experience of nearly every new region has been much the same. No place has yet been discovered where orchards will thrive where pests will not also thrive. The general truth of the statement is not affected by the well-known fact that the amount of damage caused by a particular insect or fungus varies greatly in different regions and in the same region from year to year. 5 6 The rapid spread of certain pests like the codling-moth and apple scab in recent years has led some to the opposite extreme view, namely, that pests are far more injurious here than in other fruit- growing regions. A careful comparison of the loss occasioned here in neglected orchards with similar injury in older States reveals no evidence to justify such a conclusion. Many orchardists have been slow to adapt themselves to the new con- ditions caused by the introduction and spread of insects and fungous diseases. Although these new conditions have undoubtedly increased the cost of producing fruit, the growers who have used proper efforts to control insects and disease have been uniformly successful in rais- ing profitable crops of high-grade fruits; on the contrary, the product of neglected orchards is, as a rule, so badly injured that most of it is unmarketable, or must be sold at a very low price. Serving as object lessons, such results are doing much to increase rational efforts to combat orchard enemies, and undoubtedly the situa- tion will become better from year to year, as the great majority of persons now setting out orchards realize beforehand that it is one of the factors necessary to success. HORTICULTURAL DIVISIONS. from a horticultural point of view there are three very distinct regions in the Pacific Northwest. These may be denominated as follows: (1) The Coast Region, lying west of the Cascade Mountains. (2) The Inland Valleys, having an altitude of 300 to 1,000 feet, for the most part irrigated, and in which the commercial growing of the peach is carried on. (3) The Inland Uplands, ranging in altitude from 1,000 to 3,000 feet or more, where commercial peach culture is not practicable. CONDITIONS AFFECTING ORCHARDS IN THE COAST REGION. The most striking peculiarities in the region lying west of the Cas- cades are the very equable mean temperature throughout the year and the rather copious rainfall; periods of drought seldom occur, and then only during a short time in July or August. These conditions, which have favored the heavy forestation of the region, are quite different from those in any other portion of the United States, and have already given rise to a number of new agricultural problems. Only those which particularly concern orchards are discussed here. The humid- ity of the climate quickly results in trees becoming coated with a growth of lichens, and, later, true mosses, the whole being commonly denominated ‘‘moss,” which nullifies to a considerable extent the effects of some spraying mixtures; hence, any practice to be completely successful must destroy this moss. Of the spraying compounds, fi Bordeaux mixture and the sulphur-salt-lime wash are both efficient for this purpose. The only practice that has been at all general in orchards here is winter spraying with the sulphur-salt-lime wash. Beyond any ques- tion this spray is effective on the Pacific coast against the San Jose seale. It also destroys the eggs of the green aphis and the red spider, and kills moss. It is not effective against the oyster-shell scale, nor, on mossy roughed-barked trees at least, against the woolly aphis of the apple; for apple-scab and blackspot apple canker it is of little or no value. There is no evidence at hand to indicate whether the sulphur-salt-lime wash is at all effective against the brown rot of stone fruits, but it is probably no more efficient for this than for the scab diseases. In view of these facts, winter treatment of trees west of the Cascades with sulphur-salt-lime is unsatisfactory. The efficiency of this wash seems to depend on the caustic properties of the compounds of lime and sulphur. Its high value here against the scale insects has given rise to the idea that it is a specific against practically all the ills that affect orchard trees, an idea rudely dis- pelled by the record of actual experiences. As a matter of fact the value of the wash against most fungous diseases seems to be very small and not to be compared with that of Bordeaux mixture. Up to the present time commercial fruit growing in the coast region has not been a prominent feature of its agriculture. Prune growing is as yet the one phase of fruit production that is conducted on a large scale, and this industry is confined mainly to Clark County, in Wash- ington, and the Willamette Valley, in Oregon. Inasmuchas all stone fruits except the peach do remarkably well, and apples and pears of fine quality can be grown—in fact, fully equal to those of the inland regions—it seems strange that their production on a commercial scale _ has not been more fully developed. ‘The principal explanation of the failure to do this seems to be the large loss occasioned by scab to the apple and pear, and by brown rot tothe stone fruits. Toa less degree the black-spot apple canker may have had a like effect. The control of these diseases, however, would seem to offer no more serious prob- lems than do the codling mothand San Jose scale in the inland valleys. Be that as it may, it is certainly desirable that a large additional amount of experimenting be carried on to determine how far these factors are inimical to success. Another factor that may have something to do in limiting commercial fruit growing is the higher initial cost of the land. A rational treatment for orchard trees in this region may perhaps be made most clear by considering each kind separately. THE APPLE. Throughout the coast region, apple-scab and blackspot apple canker cause the most serious losses. It 1s a conservative estimate that 75 8 per cent of the apples raised in the region are more or less affected by scab, and but a small portion of the trees are free from the canker. On the contrary, the loss by insect damage is relatively small. In western Washington not over 10 per cent of the apples are affected by the codling-moth. In the Willamette Valley of western Oregon the same insect causes a loss of from 30 to 60 per cent of the apples, accord- ing to Professor Cordley. An unimportant amount of damage is caused by the wooly aphis and by the oyster-shell scale, or bark louse. The San Jose scale is very rare in western Washington and by no means a serious factor in western Oregon. An insect recently introduced from Japan, the apple fruit miner (Laverna herellera), may become a serious pest. As yet it is not wide- spread, and so little is known of its life history that no method of treatment can be recommended. It may easily be known by the sinu- ous passages bored through the fruit by the larve. The control of fungous diseases in the coast region is rendered dif- ficult owing to the frequent rains, especially those of spring and early summer. In the case of apple scab the two or three sprayings of Bordeaux mixture usually recommended are not sufficient. Five sprayings is probably the smallest number necessary to insure good results. In the light of present experience these are best applied as follows: The first, just before the flower buds open in spring; the second, just after the blosoms fall; the third, 10 to 12 days later; the fourth and fifth, at intervals of two weeks. The last two sprayings should be with ammoniacal copper carbonate, as the Bordeaux mixture causes fruit to russet, especially when damp weather follows the spraying. There is still need that much experimental work be done on this disease under the peculiar conditions existing, as it is much the worst enemy the apple grower has to contend with. The above suggestions are admittedly based on too meager a series of experiments. The disease here designated blackspot apple canker, also known as ‘* blackspot,” ‘‘deadspot,” ‘‘apple anthracnose,” and ‘‘apple canker,” is a serious enemy, especially of young apple trees. A detailed account of the disease and of the methods for controlling it is given farther on. Where the average loss by the codling-moth is 10 per cent or less, it isa comparatively unimportant factor. It seems desirable, how- ever, to add Paris green to the third spraying of Bordeaux mixture, 1 pound of the poison to each 150 gallons of liquid. Where, as in the Willamette Valley, the loss is greater, one or perhaps more addi- tional sprayings with Paris green are necessary. For the woolly aphis, summer sprayings of kerosene emulsion, 1 part to 12 parts water, have given very satisfactory results. In west- ern Washington, at least, the root form seems not to occur. 9 THE PEAR. Pear scab is the most serious disease yet affecting this fruit in the Coast region. It requires the same treatment as apple scab. Blight, or ‘‘fire” blight, of the pear is yet unknown in western Washington, but it is reported from western Oregon. In view of the enormous damage this disease has caused in the inland regions, it is very desirable to prevent its spread as much as possible. The pear-leaf blister-mite is of frequent occurrence. THE CHERRY. Brown rot, or fruit mold, is the only disease of serious consequence. The control of this disease is difficult, but two sprayings of Bordeaux _ mixture seem decidedly helpful. One of these should be just before the flowers open, the other immediately after the petals fall. It is decidedly helpful to prune the trees so that the tops are open and the fruit exposed as much as may be to the sunshine. Of insects, the black aphis is periodically abundant. It can easily be destroyed with kerosene emulsion. Gummosis, a disease of very obscure origin, is a frequent trouble with sweet cherries. Nothing satisfactory can be recommended in the way of treatment. The common practice of slitting the bark is, at best, of doubtful value. Trees grafted on wild stock are somewhat less subject to the disease. THE PLUM AND THE PRUNE. Like the cherry, both of these fruits are subject to the brown rot. While the disease varies greatly in severity from year to year, the gathering and burning of the mummified fruits should never be neg- lected. The thinning of the fruit so as to prevent clusters is also desirable. Spraying for this disease has given contradictory results, and much experimenting is yet necessary to determine whether it is profitable or not. The peach-tree borer is prevalent in some sections, attacking par- ticularly prune trees grafted on peach roots. Digging out the larvae in fall and spring with a knife is the usual method of control. In addition some growers mound up earth about the bases of the trees in May, a practice which would seem to be always desirable, and perhaps as good as any that can at present be recommended. In the last few years the root disease caused by the mushroom, Armillaria mellea, has been prevalent in Clark County, Washington. Apparently it has been introduced, as it has not been found in adjacent woodlands. Besides the mushrooms which appear about the bases of the affected trees in the fall, the disease may be known by the black, string-like strands (rhizomorphs) which occur on the crown and roots. 10 These rhizomorphs are part of the vegetative body of the mushroom. The disease spreads by the spores produced on the mushrooms and by the rhizomorphs which grow along the roots of the affected trees and thus reach adjoining trees. No remedy is known for the disease, which is nearly always fatal, at least to prunes. The only real method of control is to dig up the affected trees, roots and all, and burn them. No new trees should be planted in the same spots for several years. An affected tree, if not at once dug up, should be isolated from adjoin- ing trees by a ditch a foot wide and two feet deep. In any case the mushrooms should be gathered and destroyed when they appear. This particular kind is edible. Some growers have tested the efficacy of lime, placing it in considerable quantity about the roots of an affected tree, and it is claimed that in some cases the trees recovered. There is room for considerable investigation in testing the usefulness of lime, of Bordeaux mixture, and of other substances in this manner, though the chances are that none of them will prove satisfactory remedies. In addition to the above, the prune especially is subject to two obscure ailments which are not caused by either insects or fungi. One of these is called ‘‘leaf curl,” and is characterized by the leaf margins rolling in loosely toward the midrib, and usually becoming more or less yellowish. In bad cases many of these leaves fall off, and some- times, at least, many of the prunes as well. The trouble usually occurs in July and August and seems due primarily to drought. At least it is common to see it in some orchards while absent from adjoining ones; and, in the same orchard, it may frequently be noticed that the trees in moister situations are normal in their appearance while the rest are affected by the ‘‘curl.” This view is held by many orchardists, and the fact that the prune is thus affected in every part of the North- west where it is cultivated lends considerable weight to the conclusion. It is a noticeable fact, however, that some individual trees are more subject to the trouble than others. Where this is the case it is usually easy to find some secondary cause, such as injury to the crown by borers or by the mushroom disease, partial girdling due to the bark bursting, or an imperfect union of the scion and stock. The other trouble is locally known as bark bursting, and seems con- fined to the Coast region. It was particularly prevalent in 1899. It is characterized by the splitting of the bark in an irregularly longitudinal direction, and not rarely being torn away from the wood for some dis- tance on each side of the split. So far as observed, this occurs only in late winter or just before the buds burst in spring. A current idea in regard to the trouble is that it results from the tree being bark bound, and a common practice based on this idea is to slit the bark from the branches to the ground. It is also claimed that leaf curl is a result of the tree’s being bark bound and that the slitting 11 process releases the pressure of the bark so that the sap can flow more freely. The bark binding is supposed to result from the wood and inner bark growing more rapidly than the tough outer bark, the strain finally becoming so great that the bark bursts and even breaks away from the wood. To all of the above views there are vital objections. The supposition that bark binding interferes with the sap flow and thus causes leaf curl may be dismissed as absurd, for it is impossible for the bark to exert pressure enough to prevent the upward movement of water in the sapwood. It is also a fact that the bursting does not take place when the wood growth is greatest and the stretching of the bark most intense. On the contrary, it takes place, if at all, near the close of the winter season, when there is absolutely no growth. That the bursting could be caused by low temperature alone seems out of the question, as in the coast region the winter temperature is so high that skating is a rare sport, and only twice in twenty years has the thermometer registered zero. In the inland areas much lower temperatures occur, but bark bursting is there unknown. With our present knowledge of the trouble no adequate explanation can be given. It has been suggested that root pressure may have something to do with the phenomenon. The conditions in winter in the coast region are frequently such that the roots may be active in the relatively warm soil long before any leaves have developed in the branches. This would result in a considerable sap pressure within the tree, but it seems hardly probable that it could be great enough to burst the bark, even in case of a sudden drop in the temperature. Whatever the cause, the best remedy is to bind the bark at once, using a liberal supply of grafting wax of some sort to keep out fungus spores. The binding should be done with strips of cloth or burlap, which should be tightly drawn. If this is done promptly the wound will heal over nicely. Slitting the bark is of doubtful value. However, it can do little harm, even if it does no good. CONDITIONS AFFECTING ORCHARDS IN THE INLAND VALLEYS. The Cascade Mountains separate two regions widely different in soil and climate. On the one side these have fostered the development of great forests; on the other almost antithetical conditions have resulted in the plains and hills being practically treeless. While the coast region has an abundant rainfall and no great extremes in temperature, the inland region, in many parts at least, has an insufficient rainfall and the extremes of heat and cold are more marked. In the fruit-growing districts of the inland region there are well- marked differences between the valleys, where for the most part irri- gation is practiced, and the uplands, where rainfall must be depended on. 12 The valleys here considered are those which lie at an altitude of 300 to 1,000 feet above the sea level, including practically all ofthe regions in which the peach thrives, and which in the main are cultivated under irrigation. In these valleys commercial fruit growing is, perhaps, more extensively engaged in at present than anywhere else in the- Pacific Northwest. } The extremely favorable conditions, so far as pests are concerned, in these inland valleys lies in the absence of any serious fungous disease. Apple and pear scab do not occur; brown rot is reported from but one locality; blackspot canker is unknown. How far these conditions are due to climate, and how far to comparative isolation, is difficult to determine. The experience of most of the older fruit-growing commu- nities is a warning to the fruit grower that there is little ground for hope of immunity from any particular pest on account of climatic influ- ences. The absence of such serious enemies as peach yellows, brown rot, and plum curculio, not to mention others, is an important factor in successful orcharding in these valleys. INSECT ENEMIES. The following are the insect pests of most importance: San Jose scale.—The first appearance of this insect in the Northwest seems to have been in the Snake River Valley, at Almota. At the present time the insect is abundant in most of the valleys and occa- sional on uplands. The universal practice is to spray in winter with the sulphur-salt-lime wash, which is completely effective when properly applied. Excepting that such winter applications entail a perennial expense, the advent of the insect has caused little damage. An inci- dental feature gained in peach orchards by these winter sprayings is the control of the peach-leaf curl, which occasionally caused consider- able damage. Codling moth.—Taken all in all this is the worst insect pest in the Northwest, and it is more destructive in these inland valleys than else- where. Owing to the long warm season, the insect may be found at almost any time, and in all stages, from May to September. It is commonly believed that in these valleys the insect has three or more annual broods, but this is by no means demonstrated. The experience of fruit growers has led them to spray from five to seven times each season to control this insect. The majority of orchardists use Paris green, but others secure as good results apparently with the cheaper arsenite of soda mixture. The sprayings as carried out by most grow- ers are as follows: The first, just as soon as the petals fall; the second, two weeks later; the third, about July 10, and the remaining sprayings at intervals of two to three weeks, the last one being in September. A few growers supplement their spraying with the ‘‘ banding system,” and believe that the results secured justify the practice. 13 Aphides or plant-lice—In some sections these are occasionally very abundant, especially those of the apple and plum. Kerosene emulsion is generally used to keep them down. Peach moth or peach twig-borer.—This insect was abundant in 1897 and again in 1900 and 1901. Winter sprayings with kerosene emul- sion as determined by experiments on Snake River are very effective. The sulphur-salt-lime wash seems to have no effect on the insect. BACTERIAL AND FUNGOUS DISEASES. Peach mildew (Sphaerotheca pannosa).—This disease is of general occurrence in peach orchards, but does comparatively little damage. Some years the disease is excessively abundant and other years scarce. I have never been able to detect any other reproductive organs than the conidia or summer spores. The fungus lives over winter on young twigs. Up tothe present time the disease has received no specific treat- ment, and, in view of the relatively small damage done, it is probably not profitable to spray against it. Pear blight.—This disease has been extremely destructive in almost every part of the inland region for three years past. It is estimated that 70 per cent of the pear trees in the region are either killed or so badly injured as to be of little value. Some varieties have withstood the disease much better than others, but strangely enough the same variety seems to differ in its degree of resistance in different localities. CONDITIONS AFFECTING ORCHARDS IN THE INLAND UPLANDS. By the uplands are meant the valleys and rolling hills having an ele- vation of from 1,000 to 3,000 feet. In general, such lands comprise the wheat-growing area of the inland region. Dependence is placed entirely upon the rainfall, which in some localities is barely sufficient to insure a crop. In wheat raising, indeed, the most common practice is to summer fallow the land each alternate year, and in the drier localities this 1s necessitated by the scanty rainfall. During recent years a great acreage of fruit trees has been planted in such lands, and the hardier fruits have proven very satisfactory investments. INSECT ENEMIES. Thus far there has been but very slight damage from insect pests. How much this is due to the relative newness and isolation of the orchards, and how much to the climatic conditions, it is difficult to determine. The following notes on such insects and diseases as have already appeared give the only indications we have as regards their probable future behavior; 14 Codling moth.—In the past four or five years the average damage caused by this insect has been less than 10 per cent. It is generally thought that this low percentage of damage is due to the cool nights of the region, to some extent aided by the prevailing fresh winds. Inasmuch as the damage occasioned by this insect in Snake River Valley is always large, while on the uplands 2,000 feet higher and only 1 to 3 miles distant the loss is nearly always small, considerable weight is given to this opinion. Nevertheless in occasional orchards in the uplands the loss has in certain years, notably 1898, reached as high as 25 and even 40 per cent. This is commonly ascribed to the peculiari- ties of the particular season, which may be the true explanation; but in view of the newness of the orchards it can not be considered as demonstrated. San Jose scale—Up to four years ago this insect was not known to occur in the interior uplands, and it was generally believed that it could not thrive there. Its occurrence in at least 4 orchards located at an altitude of about 2,000 feet has dispelled this notion. In each case, however, the spread of the insect in the orchard has been very slow, so that but little damage has been caused though no attempt _has been made to destroy it. These facts would seem to point strongly to the conclusion that outside of the peach-growing districts the San Jose scale is not likely to prove a serious menace. In every case, however, no pains should be spared to exterminate the insect, and this, by hard pruning and thorough spraying, can be accomplished. It is far more economical to exterminate the insect, if possible, than to be compelled to spray for it every year or two. BACTERIAL AND FUNGOUS DISEASES. Pear blight.—This terrible disease has been very destructive in the past three years, from 60 to 80 per cent of the pear trees in the region having been practically destroyed. Quince trees, too, have suffered severely, but apple trees have scarcely been affected. In view of the highly destructive character of this disease, the future of pear culture in the Northwest is very uncertain. Apple scab.—Of the lands here called the inland uplands, the greater portion is treeless prairie. To the northward and eastward, however, the prairies merge into the forest-clad foothills of mountain ranges, where the rainfall is somewhat greater. In these forested regions, especially in northern Idaho, the apple scab has been more or less prevalent for several years past, the amount of the damage varying in different seasons. On the adjoining prairie regions the disease seems to be spreading slowly, but until now not 2 per cent of the apples have been affected. Outside of the forest belt, at least, the present experience would indicate that the disease is not apt to become an important factor. 15 LEGISLATION. While differing considerably in character, the horticultural laws of Oregon, Washington, and Idaho aim to prevent the introduction and to control the spread of injurious insects or diseases by all practicable means, namely: Nursery stock inspection, quarantine of suspected fruit, and compulsory treatment of infested orchards. NURSERY-STOCK INSPECTION. Perhaps more attention has been given to this phase of the horti- cultural laws than to any other. Unquestionably the effect has been to make nurserymen much more careful regarding the quality of the nursery stock they ship. Without doubt, too, this inspection has to some degree limited the spread of well-known insects and diseases. It is very probable, indeed, that the cost of the service is more than re- paid by the benefits derived. But as a means of preventing the intro- duction of *new pests, nursery-stock inspection has not succeeded. With the exception of a very few dangerous insects and diseases, among them peach yellows and plum curculio, practically every serious orchard pest is now known to occur in the Northwest. It may be, and probably is, the fault of an imperfect service rather than of the method, but the fact remains that the wished-for result was not attained, and, of course, is not now attainable. QUARANTINE OF INFESTED FRUIT. In the enforcement of this phase of the horticultural laws, the exer- cise of a certain discretion is noticeable. In few, if any, cases have domestic fruits infested or injured by apple scab, codling moth, or peach moth been quarantined. On the contrary, when infested with San Jose scale, they have usually been quarantined and condemned. Imported fruit, as a rule, is subjected to much stricter quarantine than is domestic fruit. In numerous cases infested oranges and lemons have been quarantined and the owners compelled to fumigate or destroy them. The apparent object of this is not to protect.orchards, as they are in nowise threatened by such insects, but to discourage shippers and importers from handling such infested fruit. In so far as imported fruits are of the same sorts as domestic, it is certainly desir- able that the quarantine laws be strictly enforced, especially as regards Japanese fruits. The introduction of the apple fruit-miner through that source is an object lesson that should be heeded. As was pointed out in the Yearbook of the Department of Agriculture for 1897 by Dr. L. O. Howard, there are a number of Japanese insects which, if introduced, are likely to become serious pests. 16 COMPULSORY TREATMENT OF INFESTED ORCHARDS. The general enforcement of horticultural laws of this class is attended with difficulty. The actual inspection of every orchard in the State demands an amount of work that the service provided does not succeed in accomplishing. While undoubtedly the most direct means of con- trolling pests, its efficiency would probably be increased by limiting the number of insects or diseases whose control is attempted. The sentiment seems to be growing among orchardists in the Northwest that every means, including compulsory treatment, should be enforced to control insects or diseases that injure or destroy orchard trees; that this is more important than to expend the necessarily limited energy of the officials in combating pests that affect merely or mainly the fruit. It is objected by some that it is practically impossible to compel an unwilling person to carry out any compulsory treatment properly, and by others that, even if compulsory treatment for such pests as codling moth and apple scab is enforced, it will not to an appreciable degree make it cheaper for orchardists in general to raise first-class fruit. In short, it is argued that the law can not be fully enforced, and that it makes very little difference if it is. But these difficulties remain whether we consider only tree-injuring or only fruit-injuring pests. After all, the exercise of wise discretion on the part of the officers of the law would seem to be necessary. In any case it would seem wise to endeavor to prevent the spread of a new disease or insect as much as possible. So far as well-established enemies are concerned, it would appear to be wisest to enforce the law only where there is a reasonable hope of exterminating them or confining their spread. INSECTICIDES AND THEIR PREPARATION. Two general classes of insecticides are commonly used in spraying, namely, those which kill by external contact and those which kill by internal poisoning. The former are used almost exclusively against such insects as plant lice and scale insects, which obtain their nourish- ment from the plant by means of sucking beaks. The latter are useful only against insects which obtain their food by biting or gnawing. Attention to these fundamental differences will prevent the mistake too frequently made of spraying with Paris green or similar poisons for such insects as plant lice or the San Jose scale. Of contact or external insecticides the most important to the Pacific Northwest are the sulphur-salt-lime wash, kerosene emulsion, and whale-oil soap with or without, quassia. Of internal poisons the arsenicals only are used, Paris green being the most common. Paris green is sometimes adulterated, and this, in part at least, accounts for some complaints of nonsuccess attend- ing its use. To be sure that the article purchased is reliable, it is 17 always well to send a small sample to the chemist of the State experi- ment station to report upon it. Recently the arsenic and lime and the arsenic-soda-lime mixtures have been employed by some fruit growers, who report excellent results. Both of these, being cheaper than Paris green, deserve trial, and formulas are therefore given. THE SULPHUR-SALT-LIME WASH. do, si Elt 206 2 Sieh: pace tmnt cacti iad eee peace: in eA et pounds.. 40 ‘SUP POu abies Aa Se 9 ella el dea enc ln eG Sl AD et ae eae eae AE REE do 20 SOikt se SOM ee oe Ute SERA Ske a Le al RACE ie CGR Sieg Coe eed aa do 15 NURSING RICE aU Stress ene et ee oe he oa ow inde weld owe gallons.. 60 Take 10 pounds of lime and 20 pounds of sulphur, boil with 20 gal- lons of water for about two hours, or until the sulphur is thoroughly dissolved and the mixture is of deep amber color. While boiling, the © liquid must be stirred frequently. Next, place in a cask the rest of the lime and pour enough hot water over it to thoroughly slack it, and while it is still boiling add the salt and stir until it is thoroughly dissolved. Then add this to the lime and sulphur solution in the boiler and boil for ‘another hour. Sufficient water to make 60 gallons should then be added, keeping the mixture well stirred meanwhile. As the solution must be kept well stirred when spraying, it is best to use a pump with an agitator. This spray is to be used only in the winter, when the leaves are off the trees, and is most effective when applied hot. The trees should first be well pruned, and the spray applied thoroughly, care being taken that no part of the tree, not even one of the smallest twigs, does not receive its coating of the wash. This is the standard winter wash on the Pacific coast for the San Jose scale. It will also destroy the eggs of the green aphis and the red spider. As a fungicide the mixture has but small value. Some orchardists add concentrated lye to the above solution in the propor- tion of 2 or 3 pounds to the hundred gallons, claiming that the wash is made much more effective thereby. As it is completely effective without the lye, the addition of the latter seems unnecessary, and no careful experiments have yet been made which demonstrate that the lye is a desirable addition. The formula as above given is the standard one as at present used. In its manufacture some orchardists slake all the lime, adding the sulphur and salt immediately, and then boil for three hours. There appears no reason to believe that the resulting compound is any different from that obtained by the ordinary method. Up to the present very little experimenting has been carried on to determine whether modifications of this wash are as effective or more 24998—No. 153—02——2 18 effective, and there is room for much investigation in this direction. The modification known as Oregon winter wash, in which bluestone is used to replace the salt, has been somewhat extensively used. This was supposed to be virtually a mixture of sulphur-salt-lime and Bor- deaux, but chemically, at least, it is not. Theoretically, it would seem that an actual mixture of the two sprays would be better. In places where it is necessary to spray for both the apple scab and the San Jose scale, a series of experiments to test the double efficacy of such a mixture is desirable. Where the San Jose scale occurs, present experience indicates that sulphur-salt-lime is the best spray. Where a fungus alone is sprayed for, Bordeaux is probably the best fungicide. KEROSENE EMULSION. Kiergueneeu tt 7. sisiiccin ahd Pee et aS cet cogch . sess rs Sc ene Se ee aS, SNE eS) ee ee ees 50 gallons. Copper sulphate... 2c. .2oa.2- -Soscereoees. 2 eae eee ee 6 pounds. Unslacked Iinie’:2-.. 22-232. 2t es CelU: eee eee ees 4 pounds. It has been found that the method of combining the ingredients has an important bearing on both the chemical composition and physical structure of the mixture. The best results have been obtained from the use of the Bordeaux mixture made in accordance with the following directions: In a barrel or other suitable vessel place 25 gallons of water. Weigh out 6 pounds of copper sulphate, then tie the same in a piece of coarse gunny sack and suspend it just beneath the surface of the water. By tying the bag to a stick laid across the top of the barrel no further attention will be required. In another vessel slack 4 pounds of lime, using care in order to obtain asmooth paste, free from grit and small lumps. To accomplish this it is best to place the lime in an ordinary water pail and add only a small quantity of water at first, say a quart or a quart and a half. When the lime begins to crack and crumble and the water to disappear, add another quart or more, exercising care that the lime at no time gets too dry. Toward the last considerable water will be required, but if added carefully and slowly a perfectly smooth paste will be obtained, provided, of course, the lime is of good quality. When the lime is slacked add sufficient water to the paste to bring the whole up to 25 gallons. When the copper sulphate is entirely dissolved and the lime is cool, pour the lime milk and copper sulphate solution slowly together into a barrel holding 50 gallons, as shown in figure 1. The milk of lime should be thoroughly stirred before pouring. The method described insures good mixing, but to complete this work the barrel of liquid should receive a final stirring, for at least three minutes, with a broad wooden paddle. It is now necessary to determine whether the mixture is perfect—that is, if it will be safe to apply it to tender foliage. To accomplish this, two simple tests may be at used. First insert the blade of a penknife in the mixture, allowing it to remain there for at least one minute. If metallic copper forms on the blade, or, in other words, if the polished surface of the steel assumes the color of copper plate, the mixture is unsafe and more lime must be added. If, on the other hand, the blade of the knife remains unchanged, it is safe to conclude that the mixture is as perfect as it can be made. As an additional test, however, some of the mixture may be poured into an an old plate or saucer, and while held between the eyes and the light the breath should be gently blown upon the liquid for at least half a minute. If the mixture is properly made, a thin pellicle, looking like oil on water, will begin to form on the surface of the liquid. If no pellicle forms, more milk of lime should be added. If spraying is to be done upon a large scale, it will be found much more convenient and economical in every way to prepare what are known as stock solutions of both the copper and lime. To prepare a stock solution of copper sulphate, procure a barrel holding 50 gallons. Weigh out 100 pounds of copper sulphate, and after tying it in a sack suspend it so that it will hang as near the top of the barrel as possible. Fill the barrel with water, and in two or three days the copper will be dissolved. Now remove the sack and add enough water to bring the solution again up to the 50-gallon mark, previously made on the barrel. It will be understood, of course, that this —— = = — —— = Fig. 1.—Making Bordeaux mixture; Pouring together the lime milk and copper sulphate solution. second adding of water is merely to replace the space previously occupied by the sack and the crystals of copper sulphate. Each gallon of the solution thus made will contain 2 pounds of copper sulphate, and, under all ordinary conditions of tempera- ture there will be no material recrystallization, so that the stock preparation may be kept indefinitely. Stock lime may be prepared in much the same way as the copper sulphate solution. Procure a barrel holding 50 gallons, making a mark to indicate the 50-gallon point. Weigh out 100 pounds of fresh lime, place it in the barrel, and slack it. When slacked, add sufficient water to bring the whole mass up to 50 gallons. Each gallon — of this preparation contains, after thorough stirring, 2 pounds of lime. When it is desired to make Bordeaux mixture of the 50-gallon formula it is only necessary to measure out 3 gallons of the stock copper solution, and, after thorough stirring, 2 gallons of the stock lime; dilute each to 25 gallons, mix, stir, and test as already described. One test will be sufficient in this case. In other words, it will not be necessary to test each lot of Bordeaux mixture made from the stock prepara- tions, provided the first lot is perfect and no change is made in the quantities of the materials used. Special care should be taken to see that the lime milk is stirred thoroughly each time before applying. As a final precaution it will be well to keep both the stock copper sulphate and the stock lime tightly covered. 22 AMMONIACAL SOLUTION OF COPPER CARBONATE. This preparation, as now generally used, contains— WP Ater t= dete ods - need eet he atk see oe See ee See 45 gallons. SIMONE AQUA. AMNIMONIA 0... sore made Res dee ap eee 3 pints. Copper CarPONAWG son one tame ne cote ee Se eee 5 ounces. The copper carbonate is first made into a thin paste by adding a pint and a half of water. The ammonia water is then slowly added, and if of the proper strength, i. e., 26 degrees, a clear, deep-blue solution is obtained, which does not become cloudy when diluted to 45 gallons. The ammoniacal solution of copper carbonate being a clear liquid, its presence on the leaves, fruit, and other parts of the treated plants is not so noticeable as where the preparations containing lime are used. In case it is desired to keep the strong solution as a stock preparation, the bottle or jug in which it is placed should be tightly corked. In spraying the apple and pear for codling-moth and scab, time and expense may be saved by combining the sprays. In this case Paris green is added directly to the Bordeaux, using 1 pound of the poison to 150 gallons of the Bordeaux; but of course the Paris green is not to be used with the Bordeaux in the sprayings which are-applied before the trees blossom. The arsenic-lime and arsenic-soda-lime compounds may be used in the same way. In making such spraying mixtures, the Bordeaux solution is always to be considered as replacing the water, in making calculations. QUACK INSECTICIDES AND FUNGICIDES. There are always upon the market various sorts of patent spraying compounds and nostrums, which agree in one respect only, and that is in being recommended as a perfect remedy for every insect and fungus that ever attacks plants. While several of these compounds have more or less merit, none of them thus far tested are equal to the standard sprays. For the most part they are decidedly more costly and decidedly less effective. Two classes of these compounds need especial mention and con- demnation: CURE-ALL REMEDIES. These are mixtures of almost every conceivable substance that has ever been used with the slightest degree of success. One such has been advertised as containing whale-oil soap, arsenic, copper sul- phate, tar, green vitriol, and sulphur, but as a matter of fact some of — these were not present. A vital objection to such ‘‘shotgun” reme- dies, even if they possess real merit, is their greater cost. Anyone can see that when arsenic is the desired insecticide the others are use- less, and the same might be said of nearly every ingredient in turn. The idea of the manufacturer seems to be that the average farmer has not intelligence enough to make standard sprays, and hence is glad to 23 purchase one that can be used against every enemy which may attack his trees. The apparent commercial success of some of these manu- facturers seems to show that the farmer, like most of his fellows, needs to be warned against humbugs. SAP POISONS. An enticing idea to everyone that owns a tree is that it may be made immune to insects and fungi by putting some compound at its roots, or preferably in a hole bored in the trunk. Copper sulphate, either alone or mixed with other substances, seems to be a favorite remedy with people who accept the idea. Recently a mixture of this sort has been widely advertised. On analysis it was found to contain copper sulphate, bone charcoal, sulphur, and some washing powder. The charcoal and sulphur, which are insoluble in water, made up most of the mixture. The theory of such remedies is to poison the sap of the tree so that insects will either be poisoned by it or else dislike its taste, and fungi will be unable to thrive on account of it. The unfortunate flaw in the theory is that copper sulphate is quite as poisonous to the trees as it is to the pests, and a sufficient quantity of it to have the desired effect - would result disastrously to the tree. Faith in these supposed remedies would be largely destroyed if farmers would test them impartially. For example, in a horticultural meeting not long since a farmer declared that copper sulphate placed at the roots of young trees protected them from aphis attacks. He had treated thus every tree in his orchard the year before, and not one was attacked by that insect, which proved to him that the copper sul- phate repelled the aphides. As a matter of fact, it did not prove this. The thing was just as well and probably more truly explained by its not being an ‘‘aphis year.” If the farmer had treated all his orchard save a series of check trees here and there throughout the orchard, and the check or untreated trees had been attacked, while the treated trees were free from the insect, he would have had strong evidence in favor of the truth of his idea. Without such check trees by which to compare results, any series of experiments is of little value, because the results can not be clearly interpreted. If farmers would bear this fundamental part of every experiment in mind, there would soon be less success too in the quack insect-destroyer business. INSECT PESTS. In the following paragraphs the principal insects affecting orchards in the Pacific Northwest are briefly described, their habits are outlined, and the proper remedies are named: SAN JOSE SCALE. So well known has this destructive insect become that most orchard- ists are familiar with it. Its presence in an orchard is usually first 24 discovered during fruit picking. On apples and pears especially the presence of the scale is at once disclosed by the bright red ring-like spots which surround the places where the scales are attached to the fruit. No other scale insect does this; so that this peculiarity makes identification easy and certain. Red spots sometimes appear on fruit from other causes, but in such cases, of course, no scale insect will be found at the center. This fact is an important one, because it enables a fruit grower to discover promptly not only when his orchard becomes infested, but the exact trees which are attacked. When the scales are abundant they completely cover the trunk and branches, giving them a characteristic grayish mealy appearance. On scraping such a twig a yellowish oily fluid will be seen, which comes from the crushed bodies of the insects. Cutting a strip of the bark will reveal a reddish discoloration, which may also extend to the wood. The San Jose scale is at once distinguished from other related pests by the small size of the scales, which measure commonly about one- sixteenth of an inch in diameter, though rarely specimens may be found nearly an eighth of an inch across. The scales are circular and somewhat elevated in the middle, which bears a small black or yellow- ish pointed process. In badly infested orchards they completely cover the trees, giving the branches an unhealthy, grayish, scurfy appearance. In winter the scales are to be found only in half or nearly full grown condition, and completely dormant. With the first flow of sap in - spring they begin to feed again, and become fully grown in May and June, when the first brood of larvee is produced. So far as known, all these larve are born alive. They move about actively for a few hours or even a day or more, finally settling on tender twigs, leaves, or fruit, into which they gradually insert their beaks and begin to suck juices from the plant. From this time on broods are produced incessantly through the sum- mer, and the insect can be found in all stages until late in October. Shortly after settling on a spot the larva secretes a waxy substance, the beginning of the formation of a scale. Description.—The following description is quoted from Dr. L. O. Howard, Entomologist, U. S. Department of Agriculture: In two days the insect becomes invisible, being covered by a pale grayish-yellow shield, with a projecting nipple at the center. This nipple is at first white in color. Twelve days after hatching the first skin is cast. The males at this time are rather larger than the females, which have large purple eyes, while the females have lost their eyes entirely. The legs and antennz have disappeared in both cases. Six days later the males begin to change to pupz, while the females have not yet cast their second skin. At this time the females are so tightly cemented to the scale that they can not be removed without crushing. In two or three days more, or twenty to twenty-one days after hatching, the females cast their second skin, which splits around the margin of the body. At twenty-four days the males begin to issue, 25 emerging from the scales as a general thing at night. At thirty days the females are fully grown, and embryonic young can be seen in their bodies, and from thirty-three to forty days the larve begin to make their appearance. The adult male is a delicate two-winged creature, bearing a straight stoutish appendage at the posterior end. It lives in this adult condi- tion but a short time. The female never attains wings or leaves the scale after it is once formed. Only in the active larval condition can the pest become spread. This is greatly facilitated by the habit of the larve of crawling on other insects or on the feet of birds, and being thus-carried from tree to tree. Remedies.— The sulphur-salt-lime wash applied in winter is a com- pletely effective remedy on the Pacific coast. The ordinary practice in the Northwest is to spray in late winter after pruning. Care should be taken to spray every branch even to the very tip. If only a few of the insects escape, the whole tree may be again covered with them before the fruit is mature. THE CODLING MOTH. Fortunate, indeed, is the orchardist who does not know this insect from actual experience, yet there are portions of the Northwest where it is yet unknown. The insect is the common ‘‘ worm” of the appleand pear, and in the orchard may be easily detected (1) by the brownish castings which are thrust out of its burrow and then cling to the side of the fruit and (2) from the fact that many of the injured fruits fall prematurely to the ground. Description and habits.—The larva is the young of a small purplish- brown moth, which measures a little more than half an inch from tip to tip. The first moths usually appear shortly after the apple trees are in bloom, but in the warmer regions they may appear before the blossoms open. The females deposit their eggs usually on the young apples, one or two ina place, and are capable of laying 40 or 50 eggs. In from six to eight. days these eggs hatch into minute larve or ‘‘ worms,” which soon burrow into the young fruit, usually at the blossom end. Reaching the core when half grown, the larva eats out an irregular cavity, and sometimes may be found eating the seeds. The castings are thrown out through the hole by which the worm entered, or when the larva is full-grown and about to leave the apple, through a hori- zontal hole bored to the side. These castings are of a rusty reddish color and make the wormy apples quite easy to detect at this time. In about three weeks the larva reaches its full size and then leaves the fruit, either by crawling out of the hole and thence onto the tree or by dropping to the ground on a silken thread which it spins; many of the injured fruits drop to the ground, and not rarely this happens before ‘ 26 ifs / / / the larva has attained its full growth. In such case the worms crawl out of the fruit almost immediately. The larvee seek for protected places, such as crevices in the bark or cracks in the soil, and there spin thin cocoons, in which they soon change to brownish pupz. In from twelve to twenty days the adult moths emerge, and a few days later eggs are laid from which a second brood of larvee develops. The larve of the second brood are peculiar in that they usually enter the fruit from the side, a favorite place being where apples touch. In most sections this second brood is quite distinct from the first in time of appearance, and the larve for the most part hibernate over winter. In the warmer valleys, however, there is a continuous succession of individuals from the first to the second broods, and even until the crop is harvested the insect may be found in every stage. This has usually been interpreted as indicating the existence of three or more broods. ef The larve of the last brood in the year hibernate over winter in silken cocoons, and change into pupe the following spring. The moths are rarely seen unless specially looked for or reared from pupe. They fly mostly in the evening, and are not attracted to lights. Remedies.—Spraying with the arsenicals is by far the most satis- factory means of combating this insect. The most important applica- tion is the first, which should be applied as soon as the petals fall from the blossoms, but not before. A prime object is to have the blossom end of the young pear or apple filled with the poison, as this is where the worm usually enters. In order to do this the fruit must be sprayed before the calyx cup at the blossom end closes, which is shortly after the fruit sets. Some growers spray the solution with considerable force, claiming that it yields better results by getting more poison in the calyx cup. A second spraying, about two or three weeks later, seems always profitable. The value of either of these sprayings may be completely destroyed by heavy rains following the application, in which case they will need to be repeated at once. These two sprayings are all that are necessary in the greater part of the Coast region and in the inland uplands. In the warm inland val- levys, however, more sprayings are required. Different growers apply these later sprayings at somewhat different dates. The third spray- ing is commonly given about July 10 to 15, the others at intervals of three weeks, the last in September. In addition to spraying, some growers, especially in the warmer valleys, use the ‘‘ banding system” as an additional means of protec- tion. In this practice advantage is taken of the habit of the larvee of seeking sheltered places in which to pupate. The simplest way is to fasten a strip of burlap around the trunk of the tree a foot or so above the ground. The burlap should reach around the trunk, and is con- veniently fastened with a nail. If the trunk of the tree is clean and = 27 free from loose bark most of the larve which escape the spraying will pupate beneath the burlap band and may there easily be killed. Where this system alone is depended on the bands are examined every ten or eleven days, because if a longer time elapses many of the moths will emerge. This practice alone is by no means as efficient as spraying alone. It would seem that, in any case, it would be desirable to use the bands to trap as many as possible of the last brood each year, thereby lessening the injury from them the following spring. THE PEACH TWIG-BORER. This insect injures the peach in two very different ways, namely, by burrowing into the fruit, making the so-called ‘* wormy” peaches, and by boring into the twigs, which it frequently kills. Description and habits.—The insect is usually noted in gathering the later varieties of peaches, the earlier ones being quite exempt, as a rule. The worm enters at the stem end, and usually bores into the seed, which it seems to prefer. In such cases the stone usually splits as the fruit ripens. At other times the worm burrows only through the flesh, making irregular tunnels. Whether the seed is attacked or not seems to depend on how far the stone has hardened when attacked. The larva is pinkish or dirty brown in color, about one-half an inch long, and very commonly changes into a pupa inside the split stone. The adult is a small, dark-gray moth, marked on the fore-wings with a few dark spots and streaks. Both pairs of wings are bordered with a paler fringe. These adults issue in August and later, and lay their eggs in or near the crotches of the branches. When the eggs hatch, the young burrow into the bark in the crotch and feed on the soft, spongy bark until the succeeding spring. Their presence during the winter is disclosed by the fine brownish castings which are thrown out and become heaped up at the entrances to the burrows. Just as the leaves are developing in the spring they leave their winter quar- ters, and for a short time feed on the tender shoots. They bind the young leaves together loosely with silk threads, and later, when some of these leaves or the whole twig turns brown from the injuries, the work of the insect is very conspicuous. At this time, however, the larva has usually left the leaves, and in some secluded place transforms into a pupa. From this the moth soon emerges and lays the eggs from which hatches the brood which attacks the fruit. According to Marlatt it is a third brood and not the second which enters the fruit. Remedies.— Excellent results have been reached in Snake River Val- ley by spraying the trees in winter with kerosene emulsion, used preferably somewhat less diluted than for ordinary purposes. The castings at the mouths of the winter burrows readily absorb the oil, which penetrates into the holes and destroys the worms. The sulphur-salt-lime wash has no appreciable effect on the insect. 28 THE WESTERN PULVINARIA OR COTTONY SCALE. This insect is considered to be merely a variety of the Eastern cot- tony maple-scale, but it is very different in its food plants. While the Eastern insect attacks only the maple, the Western variety never is found on maples but has quite a long list of host plants, namely, cur- rant, gooseberry, pear, mountain ash, lilac, alder, poplar, hawthorn, and willow. So far as known the life history is as follows: During May and June the female lays the eggs in large numbers in a mass of white waxy fibers secreted from the posterior end of her body. As the eggs develop they expand the waxy mass and raise the insect’s body to a considerable angle to the twig on which it is attached. If the waxy mass is crushed at this time blood-colored streaks appear, arising from the eggs and the bodies of the young larve which hatch from the eggs. These larve resemble lice and run about over the plant actively. About the time the last eggs are laid the female dies, but the tough leathery scale and the fluffy mass of fibers cling to the twig for a long time. The young insects settle themselves on young twigs, insert their beaks, and begin to suck sap. They increase in size rapidly, after having covered themselves with tough waxy substance for protection, and reach their full size in August. About this time the male insects, which are narrower than the females, change into pup and soon after emerge as delicate two-winged creatures. After a few days’ life, in which they pair with the female, they perish. The females never become winged and seldom leave the branch on — which they are born. After the flow of sap ceases they become dor- mant until the following spring. As the female never acquires wings it seems at first sight difficult to account for the spread of the insect. Perhaps the most effective means of spreading the insect has been by infested nursery stock, as the insect is inconspicuous in winter. No doubt birds now and then carry the active young larvee, which have crawled upon them, for consider- able distances. Only thus can the fact be explained when the insect is found on a wild tree some distance from the nearest garden. Remedies.—Spray during May and June with kerosene emulsion or whale-oil soap solutions, the aim being to destroy the young larve. Two sprayings are necessary, the first about the time the cottony mass is most conspicuous, the second a week or ten days later. On currant and gooseberry bushes the first spraying would be at the time the fruits are fully grown but before they have begun to ripen; the second spraying may be deferred until the crop is picked. Winter spraying with the sulphur-salt-lime wash or with a strong solution of whale-oil soap, using 1} or 2 pounds of the soap to a gallon of water, would doubtless prove completely effective, but so far as we know the actual experiment has not been carried out. ar 29 THE GREEN APHIS OF THE APPLE. Description and habits.—In winter a sharp inspection of the apple trees in the orchard will usually reveal the fact that some of them have their twigs literally covered with shiny black oval eggs, large enough to be seen easily with the naked eye. About the time the leaves develop in the spring these eggs hatch, and, curiously enough, all of them give rise to females. These females are peculiar in that after a few days they give birth to living young, and this without having been fertilized. They are, therefore, called agamic or virgin repro ducing females. Similar broods follow each other quickly throughout the summer, and reproduce with wonderful rapidity. All of these summer broods, like the first, are composed of agamic females. Some of the broods are wholly or in part winged, and such spread the pest to other trees or orchards. As cold weather approaches there is pro- duced a brood of perfect males and females. The latter lay the fer- tilized winter eggs by which the life of the insect is tided over to the following spring. This insect varies in its abundance from year to year, and some places are much more troubled with it than others. In most orchards only a small portion of the trees are attacked, the insect seeming to pick out the weak or sickly ones especially. The damage done is not very great, but the attacked trees are unsightly on account of their distorted leaves and the dirty-black appearance caused by the excre- tions of the aphides. Natural enemies.—On an aphis-infested tree are always found many other insects. The lady birds and lace-wing flies feed on the aphides and destroy great numbers of them. Ants are attracted and feed on the honey dew which the aphides excrete from two tube-like processes on their backs. It is a popular mistake that the ant destroys the green aphis. This is not the case. Besides the above, many other insects are found. Some are parasites of the aphides, but most of them are attracted by the honey dew. : Remedies.—It pays to search out in the winter the trees which are coy- ered with eggs, and either to cut off the infested twigs or to spray the tree with sulphur-salt-lime, which kills the eggs. It does not pay to winter-spray a whole orchard for this insect, as is sometimes done. Perhaps the most satisfactory method of controlling this insect is to spray with kerosene emulsion after the insects appear and before the leaves curl up from their attacks. It may be necessary to spray sev- eral times during the summer. The same method is the best one for combating other species of aphis which attack trees. 30 THE WOOLLY APHIS OF THE APPLE. - Description and habits.—This insect exists in two forms, one of which attacks the roots, the other the trunk and the branches of apple trees. A great majority of the individuals are wingless, but winged ones also occur, especially in the later broods of the year. The species derives its name from a peculiar white fluffy substance which exudes from the insects’ bodies, making them appear as though covered with cotton, and rendering them very conspicuous on the trees. They are especially liable to be abundant on the suckers from the bases of trees and in the forks of the branches. The cottony covering serves to some extent as a protection, so that this species is rather more difficult to kill than other aphides. - The root form of insect is the more injurious. By its attacks pecul- iar galls are formed on the roots, in the crevices of which the lice may be found. These galls not only interfere seriously with the functions of the roots, but also form centers of decay, and may cause the death of the tree. The branch form weakens the tree by feeding on the sap, and not infrequently causes the bark to split in places as the result of its attacks; it never forms true galls like the root form. The entire life of the woolly aphis is spent on the apple tree, the winter eggs being laid in sheltered crevices. It must be understood that the two forms differ mainly in their mode of life. The presence of either form will sooner or later give rise to the other, and badly infested trees are sure to be attacked both on the roots and on the branches. ; This insect is most abundant in the Coast region. In Washington the writer has frequently searched for the root form without success. Professor Cordley reports it from the Willamette Valley. Remedies.—This pest is far more likely to be introduced on nursery stock than in any other way. The roots of purchased apple trees should always be examined for tbe galls of this insect; if the galls are large or numerous, reject the trees. If they are small and few, they may be completely disinfected by dipping the roots in kerosene emulsion or in hot water (120°-140° F.) for a moment. If trees in the orchard are attacked by the root form, the soil should be removed as much as possible from them and the roots thoroughly treated with kerosene emulsion or with water heated nearly to the boiling point. For the branch form, spray with kerosene emulsion, using rather stronger solutions than for other aphides. The root galls caused by this insect should not be confounded with those of the crown-gall disease described elsewhere. Trees infested with the latter disease can not be disinfected by any known means. The safest rule is not to accept any trees with galls on the roots. 31 THE PEAR-LEAF BLISTER-MITE. The presence of this pest is readily known by the bright red pimple- like spots that appear on the young leaves. Later these spots turn green and then brownish, forming cork-like thickenings on the under sides of the leaves. The cause of the spot is a minute four-legged mite, scarcely visible to the naked eye, and measuring but one one- hundred-and-fiftieth of an inch long. Its body is cylindrical in form and marked crosswise by numerous fine strie. As soon as the leaves burst from the buds in spring the mites burrow into them, forming the bright red galls, which are hollow and have minute openings on the under sides of the leaves. In these galls eggs are laid, which soon hatch into young mites. As fast as new leaves come out the mites migrate to them, forming new galls, and this process continues as long as leaves are developed. Before the leaves fall in autumn the mites crawl back to the twigs and pass the winter in cracks in the bark and similar places, but more particularly beneath the scales of the winter buds. At no stage of the mite’s life is it able to move fast, but the pest becomes spread from tree to tree by crawling on insects, the feet of birds, and probably in other similar ways. The damage done is sometimes quite severe, as the function of &he leaves is seriously impaired by their attacks. The affected leaves also fall prematurely. Remedies.—Experiments with this pest have not been very satis- factory. Spraying in winter when the mites are under the bud scales with kerosene emulsion diluted only three times gave the best results, but this strength also injured the trees somewhat. In no instance were all the mites destroyed. Protracted periods of cold weather are fatal to the pest, and it was almost exterminated in the inland region during the winter of 1898-99. BACTERIAL AND FUNGOUS DISEASES. BLACKSPOT APPLE CANKER. wescription.—This disease has been demonstrated by Newton B. Pierce to be caused by a fungus which has recently been named by Peck, Macrophoma curvispora, and later by Cordley as Malicorticis glaosporium. As the disease is unknown save in the Coast region of the Northwest, it is in all probability native, though it has not yet been found on wild trees. Apparently it attacks only the apple. Similar but far less serious diseases occur on both the pear and prune. The blackspot disease is confined to the bark, and derives its name from the characteristic dark brownish or nearly black spots which it causes. These spots appear only on smooth bark in which no cork has developed. Hence on old trees they are found only on the branches and twigs, but on young trees occur everywhere, being usually most 32 numerous on the trunks. The spots appear mostly in fall and winter, from November until January. They may easily be detected when no larger than a pin head. They increase quite rapidly in size and at the same time grow deeper, penetrating through the bark into the ' sap wood beneath, as evidenced by the brownish discoloration. Nature of injury—Almost from the first the spots are slightly sunken below the surrounding healthy bark, a fact evidently caused by the death and shrinking of the tissue. When the spots have _ attained their full dimensions, which occurs in February and later, the epidermis of the bark at the edge of the discolored spot commonly bursts. Still later in the season this deepens into a crack, which sharply separates the diseased from the healthy tissue. When once this crack has appeared the limit of the growth of the spot is reached, and beyond this limit it never spreads. The mature spots vary greatly in size and shape. Ordinarily they are oval, from 1 to 3 inches long and about half as wide; quite commonly two or more spots merge together, and not rarely girdle the trunk or branch. Sometimes the diseased areas are from 1 to 2 feet in length and completely girdle the attacked branch for the whole distance. On small twigs a similar girdling is very common. When the spots are six months or more old numerous pustules as large as a pin head or larger burst through the dead epidermis. At first these pustules are whitish from the numerous spores borne on their surfaces, but as the spores fall off they become blackish. These spores are curved, colorless, about one-sixteen-hundredth of an inch long and one-fourth of that in width, and are borne singly on stalks as long as the spores. These spores are blown about in the air and by them the disease is spread. A spore will germinate readily in water, sending out a germ tube which later becomes branched into a myce- lium. In nutrient substances this mycelium bears numerous second- ary spores from the ends of short lateral branches. Under natural conditions these secondary spores seldom occur. The primary spores are able directly to give rise to new spots on healthy bark, the germ tubes apparently entering through a lenticel. This then completes the life history of the fungus as it occurs under natural conditions. About the time the spores become mature the dead bark has usually separated from the wood beneath, being uplifted by the surrounding growing bark and wood, and sooner or later falls off, leaving the characteristic scars of the disease. When these scars are small and few, the new wood and bark may in time completely cover them. Un- fortunately the spots are usually numerous enough to partially girdle the tree and so seriously weaken it as to make it almost worthless. Not rarely the trunks of young trees or the branches of older ones are completely girdled, which necessarily results in the death of all parts above such injury. 33 Remedies.— When the disease first appeared a common practice was to cut out the diseased spots while small and to paint over the result- ing wounds. This was practicable only on the trunks of young’ trees, and where the spots were few was fairly satisfactory. When, how- ever, a young tree trunk has dozens or even hundreds of such spots the remedy is nearly as bad as the disease, besides being extremely laborious. On the branches of old trees such a method is utterly impracticable. From the foregoing account of the disease it is evident that the time when the tree needs protection most is from November 1 to February 1, and perhaps even later; at any rate, this is the period when most of the spots begin. Apparently such a fungicide as Bordeaux mixture should protect the trees during the period. The greatest difficulty arises from the fact that even Bordeaux mixture will not withstand the frequent fall and winter rains which prevail, unless applied several times. An ideal remedy would bea solution as effective as Bordeaux mixture for fungicidal purposes, and which would not wash off as readily. Experiments to discover such a wash if possible are now in progress. APPLE SCAB. Description.—Scab is without doubt the most destructive fungous disease in the Coast region. It commonly attacks both the leaves and the fruit, and sometimes occurs on young twigs as well. On the fruit the fungus forms circular spots of a dark smoky green or nearly black color, usually marked at the edge by a pale line where the skin of the apple is slightly raised. These spots begin to appear when the fruit is half grown, or even earlier. Single spots may reach the size of a dime, but ordinarily they are smaller. When close together they frequently unite and may thus occupy a considerable area. The effect of the fungous spot is to retard the growth of the apple tissue in its immediate vicinity, and when a number of spots are close together the - apple becomes more or less distorted on that side. Where several spots merge together, irregular radiating cracks may appear. On the leaves the fungus appears as dark olive green spots which are not sharply limited. They occur mostly on the upper side of the leaf, which may, indeed, be completely covered. The growth of the apple leaf where the spots occur is much hindered, so that the leaves are more or less curled or hummocky. Microscopic examination of the fungus either from the leaves or fruit reveals that the part of the fungus seen consists of short upright stalks, each of which bears a single oval or spindle-form spore, which may or may not be divided by a cross partition. These spores float about in the air and thus spread the disease. In comparatively rare cases where the twigs are attacked, the fungus lives over winter and in early spring again produces spores. Ordi- 24228—No. 153—02 3 B4 narily, however, the disease commences in the spring from spores blown off the fallen leaves, or those which lodge in the crevices of winter buds. Remedies.—In the light of present experience, three sprayings of Bordeaux mixture and two of cupram are necessary to insure a clean crop in the Coast region. The first spraying of Bordeaux should be just before the blossoms open, the second just after the petals fall, and the third ten or twelve days later. The two sprayings of cupram should follow the last spraying of Bordeaux at intervals of two weeks. Bordeaux should not be used for the fourth and fifth spraying, as it causes fruit to russet. It is always good practice to prune the tops of trees, so as to induce an open growth. In such trees the apple scab causes conspicuously less damage than in dense ones. PEAR SCAB. This disease is so closely similar to the apple scab that no detailed account of it is necessary. Like the apple scab, it is much more injurious to some varieties than to others. In susceptible kinds such as the Winter Nelis, the twigs are very commonly attacked by the fungus, and in this as well as other varieties a large portion of the blossoms may be killed by the fungus on the flower stalk. This emphasizes the importance of the early sprayings, which are to be applied as recommended for the apple. BROWN ROT OR FRUIT MOLD. Description.—This is the only serious fungous disease of the plum, prune, cherry, and peach yet known in the orchards of the Northwest, where it has become introduced within the last few years. Usually the first symptom of this disease to attract attention is the numerous grayish-white pustules that appear on the attacked fruit when it is nearly ripe. The pustules consist of the reproductive bodies or spores _ of the fungus, and under the microscope are seen to be oval in shape and arranged in rows, like chains of beads. The disease is scattered by these spores being carried by the air currents, or in some cases by insects. Under favorable conditions the spores quickly germinate, sending out a germ tube that will penetrate a healthy fruit and soon cause it to rot. In the laboratory a single spore placed on a plum or cherry will develop so far in twenty-four hours as to produce new spores. From this it is easy to understand why the disease spreads so rapidly in orchards under favorable circumstances. In some cases a whole crop may be destroyed within a few days’ time. A curious feature of this fungus is that it causes the attacked fruit to become dry and hard, in which condition it may remain hanging on the tree for a long time. It is mainly on these fruits that the fungus passes the winter, and on such fruit the spores may be found in abun- 35 dance in the spring. While the spores will germinate almost imme- diately after they are formed, they can also withstand hardships, and will grow after they have been kept two years. The pustules or blisters just described constitute only the reproduc- tive parts of the fungus. In the interior of the fruit may be found innumerable filaments which make up the mycelium or vegetative part of the fungus. Besides the fruit, the fungus also attacks the leaves, the flowers, and the twigs. When the flowers are affected they become brownish and rotten. In most cases it is through the stalk of the flower that the fungus enters the twig, where it sometimes causes serious damage, especially in the case of peach trees. The mycelium in the twigs lives from year to year, and the fungus may in this way have been intro- duced into the Northwest. The disease spreads much more rapidly in damp weather than in dry, so that the amount of damage it does is much more serious in some seasons than others. Remedies.—As the fungus passes the winter mainly on the mummi- fied or dried up fruits, these should always be gathered and burned. This treatment alone will often lessen the loss very materially. It is also desirable to thin the fruit so that no clusters remain. Where a cluster of fruit is left, it frequently happens that all in the bunch are destroyed. Spraying has not yielded perfectly satisfactory results with this disease on account of injury to the foliage. Two sprayings of Bor- deaux—one just before the blossoms open, the other just after the petals fall—are usually recommended. The second spraying should be made with a Bordeaux containing a large excess of lime. Any later spraying is liable to result in defoliation of the trees. PEAR BLIGHT. This disease, which was exceedingly bad in 1899 and 1900 and hardly less so in 1901, may readily be recognized from the fact that the leaves and twigs of attacked branches turn black, giving the tree the appear- ance of having been scorched by fire, hence the popular designation, **fire blight.” As has been fully demonstrated, the disease is caused by aspecies of bacteria or microscopic organism. As a result of the investigations made by Waite,* the life history of this germ and the proper treatment for it are now well understood. The attack usually begins in the blossoms, less commonly in young twigs or young leaves. The disease rapidly works down the cambium layer between the bark and the wood, and the foliage quickly blackens. The leaves are quite often directly attacked by the disease, in which case only portions of them are blackened. It is uncommon for the disease to work down into the twig from the leaf. *M. B. Waite. The Cause and Prevention of Pear Blight. Yearbook U. S. Dept. of Agr., 1895, pp. 295-300. 36 Besides the pear, the same disease affects the quince and the apple. The apple is, however, quite resistant and rarely suffers injury. The first appearance of the disease is usually after the flowering time. In 1901, owing probably to the cold weather, the disease did not become noticeable till the fruit was fairly well grown. An attacked branch is always killed and not rarely the whole tree succumbs. If left alone the disease usually continues to go down the branches during the greater part of the summer. Sooner or later, however, it ceases, and in the fall of the year one will find that in a majority of the black- ened limbs, where the leaves cling a long time, there is a well-defined line between the dead blackened part and the healthy bark. On these limbs the disease has died out. On the other limbs, especially water sprouts, it will be found that there is no such line of demarcation, but the diseased portions fade insensibly into the healthy ones. On cut- ting into such a branch it is found to be moist, not dry as in the case of the dead limbs. It is in these comparatively few limbs that the blight germ lives over the winter. With the renewed growth in spring it frequently happens that a slimy sap exudes out of these limbs, which is swarming with the germs of the disease. Flies and bees are attracted to the juice, and then flying to the flowers are almost sure to leave in the honey pit some of the germs which have become attached to their beaks or feet. In the honey of the flower the germs rapidly multiply, and work thence downward into the twigs. As bees are very abundant on trees in flower it may readily be seen how the disease becomes spread. Culture methods.—A peculiar fact about this disease is that it attacks first the most thrifty trees; slow-grown stunted trees are less liable to it. This fact has been taken advantage of in blight-infested regions by planting the pear and quince trees in very poor soil, thus insuring slow growth and a consequent partial immunity from the disease. In richer Jands the pear orchard should not be cultivated. In irri- gated lands no more water should be given the pears than is absolutely necessary. It is well, too, not to prune the trees much, as this tends to force new growth, which is more favorable to the disease. Such methods are of value in the handling of a pear orchard. Summer pruning.—In any case recourse must be had to cutting out the blight. This should be done as soon as it appears, care being taken to cut off each diseased sprig or branch well below the lowest trace of the blight. If the disease has run down a short lateral to a main branch, the latter must be cut off below the origin of the lateral. If the disease has reached the main trunk the tree is doomed. In this pruning it is quite easy to get the knife or the shears covered with the germs and thus spread the disease each time a cutis made. It is there- fore well to dip the knife or shears now and then in a strong solution of carbolie acid, which will destroy any germs that may be on it. 37 Asa result of considerable experience in summer pruning of the pear blight, we are able to say that the common fault is that the limbs are usually cut off too near the part which is diseased. It is best to make the cut at least a foot below the lowest blackening visible. In certain cases the disease may even have spread farther down than this without showing on the surface. Fall or winter pruning.—This is, after all, the most important method of combating the disease. Examination of pear trees in the early winter will disclose the fact that most of the blighted limbs still have the dead leaves clinging to them, while the healthy limbs are bare. Careful search will also reveal the fact that in most of the limbs the disease has run its course and a sharp boundary line exists between the dead dry bark and the living green bark. It is of no importance whatever whether these dead blighted limbs be removed or not. In them the blight germ has perished and from them there can be no further spreading of the disease. In a very few cases, however, especially in young water shoots, it will be found that the bark is black and juicy, not dry, and that the disease-darkened bark fades gradually into the healthy bark. In these the blight germ is living, and it is in such branches that it survives the winter. If every branch containing living germs could be cut off in winter well below the lowest trace of the disease, pear blight could be exterminated. But a single limb of this kind may infect a whole orchard the following season. It is preferable to burn such branches; but if the pruning is done before February it is not necessary. It is very important, however, to take care that new inoculations of the disease are not made with the prun- ing knife or pruning shears. Merely cutting into diseased branches and then healthy ones frequently starts new infections; therefore, extreme care must be taken to keep the tool used free from the living germs. To avoid the danger of losing the whole tree or larger branches the trunk should be kept free of water shoots and the fruiting spurs should be removed from the lower parts of the larger branches as suggested by Waite. If this is not done the blight may run down the short fruit spur and thus destroy a large branch. It is safe to say that 90 per cent of the infections which take place in the flowerless sprouts are probably caused by the punctures of insects which have just visited diseased parts. Experiments indicate that in no case can the blight enter an uninjured leaf or twig. Virulence of the disease in the Northwest.—The above recommenda- tions are based on the records of Eastern experience with the disease. It must be confessed the three years’ experience with the disease in the inland fruit-growing districts of the Northwest have been dis- couraging. Intelligent use of the knife both in summer and fall will enable one to save his trees, more or less mutilated, however. 38 It would seem that the disease here is remarkably virulent. At least, the writer has been able to find no records of such wholesale destruction as it has caused in these inland districts. Unless the viru- lence of the disease should become lessened in the course of a few years, a phenomenon that would not be without parallel, the future of pear growing in these inland areas is not clear. Some varieties, like Flemish Beauty, are notably more resistant than others, and a bright ray of hope exists in the possibility of transfer- ring this resisting power to other varieties. This, however, will require many years of experimenting. The Idaho pear is particularly susceptible to blight, and should not be planted in infested districts on that account. . CROWN GALL OR ROOT GALL. This disease causes galls to appear on the roots of various trees and shrubs. On. fruit trees it commonly forms spherical swellings of various sizes, occasionally as large asa walnut. These globular bodies have usually a peculiar warty surface. They should not be confused with the galls formed by woolly aphis, which, moreover, are smaller and usually oval or irregular. Besides in aphis galls some of the ‘*wool” is usually to be found. It frequently happens that when the roots are affected with this disease the secondary roots are abnormally abundant and often some- what spongy in texture. Particular attention is called to this disease because a good many nursery trees have been sold in the Northwest with the roots affected by it. A safer rule is to reject all trees diseased with the galls, even if the latter have been removed. We have found that they are sure to appear again. No remedy is known, and, as the disease appears to be contagious, every effort should be made to prevent the sale of nursery stock affected by it. Prof. J. W. Toumey has recently discovered in Arizona that the crown gall of the almond is caused by a slime mold which he names Dendrophagus globosus. I have been unable to discover this or any similar organism in the galls on apple roots. 39 FARMERS’ BULLETINS. The following is a list of the Farmers’ Bulletins available for distribution, showing the number, title, and size in pages of each. Copies will be sent to any address on application to Senators, Representatives, and Delegates in Congress, or to the Secre- tary of Agriculture, Washington, D. C. The tinued, being superseded by later bulletins. 16. Leguminous Plants. Pp. 24. 92. 21. Barnyard Manure. Pp. 32. 93. 22. The Feeding of Farm Animals. Pp. 32. 94. 24, Hog Cholera and Swine Plague. Pp. 16. 95. 25. Peanuts: Culture and Uses. Pp. 24. 96. 27. Flax for Seed and Fiber. Pp. 16. 97. 28. Weeds: And How to Kill Them. Pp. 98. 29. Souring and Other Changes in Mil vee 23. 99. 30. Grape Diseases on the Pacific Coast. “Pp. 15. 100. 31. Alfalfa, or Lucern. Pp. 24. 101. 32. Silos and Silage. Pp. 32. 102. 33. Peach Growing for Market. Pp. 24. 103. 34. Meats: Composition and Cooking. Pp 29. 104. 35. Potato Culture. Pp. 24. 105. 36. Cotton Seed and Its Prcducts. Pp. 16: 106. 37. Kafir Corn: Culture and Uses. Pp.12. 107. 38. Spraying for Fruit Diseases. Pp. 12. 108. 39. Onion Culture. Pp. 31. 109. 40. Farm Drainage. Pp. 24. 110. 42. Facts About Milk. Pp. 2y. ine 43. Sewage Disposal on the Farm. Pp. 20. 112. 44, Commercial Fertilizers. Pp. 24. 113. 45. Insects Injurious to Stored Grain. Pp. 24. 114. 46. Irrigation in Humid Climates. Pp. 27. 115. 47. Insects Affecting the Cotton Plant. Pp, 32. 116. 48. The Manuring of Cotton.. Pp. 16. lee 49. Sheep Feeding. Pp. 24. 50. Sorghum as a Forage Crop. Pp. 20. 118. 51. Standard Varieties of Chickens. Pp. 48. 119. 52. The Sugar Beet. Pp. 48. 120. 58. How to Grow Mushrooms. Pp. 20. 121. 54. Some Common Birds. Pp. 40. 122. 55. The Dairy Herd. Pp. 24. 123. 56. Experiment Station Work—I. Pp.31. 57. Butter Making on the Farm. Pp. 16. 124, 58. The Soy Bean asa Forage Crop. Pp. 24. 125. 59. Bee Keeping. Pp. 32. 60. Methods of Curing Tobacco. Pp. 16. 126. 61. Asparagus Culture. Pp. 40. APE 62. Marketing Farm Produce. Pp. 28. 128. 63. Care of Milk on the Farm. Pp. 40. 129. 64. Ducks and Geese. Pp. 48. 130. 65. Experiment Station Work—II. Pp.32. 131. 66. Meadows and Pastures. Pp. 28. 67. Forestry for Farmers. Pp. 48. 132. 68. The Black Rot of the Cabbage. Pp. 22. 133. 69. Experiment Station Work—III. Pp.32. 134. 70. Insect Enemies of the Grape. Pp. 23. | 71. Essentials in Beef Production. Pp. 24. i) alsa 72. Cattle Ranges of the Southwest. Pp. 3. 136. 73. Experiment Station Work—IV. Pp. 32. 137. 74, Milk as Food. Pp.39. 138. 75. The GrainSmuts. Pp. 20. 139. 76. Tomato Growing. Pp. 30. 77. The Liming of Soils. Pp.19. 140. 78. Experiment Station Work—V. Pp. 32. 141, 79. Experiment Station Work—VI. Pp. 28. 142. 80. The Peach Twig-borer. Pp. 16. 81. Corn Culture in the South. Pp. 24. 143. 82. The Culture of Tobacco. Pp. 24. 83. Tobacco Soils. Pp. 23. i44. 84. Experiment Station Work—VII. Pp. 32. 145. 85. Fish as Food. Pp.30. 146. 86. Thirty Poisonous Plants. Pp. 32. 147. 87. Experiment Station Work—VIII. Pp. 32. 148. 88. Alkali Lands. Pp. 23. 149. 89. Cowpeas. Pp. 16. 150. 91. Potato Diseases and Treatment. Pp.12. missing numbers have been discon- Experiment Station Work—IX. Pp. 30. Sugar as Food. Pp. 27, The Vegetable Garden. Pp. 24. Good Roads for Farmers. Pp. 47. Raising Sheep for Mutton. Pp. 48. Experiment Station Work—X. Pp.32 Suggestions to Southern Farmers. Pp. 48. Insect Enemies of Shade Trees. Pp. 30. Hog Raising in the South. Pp. 40. Millets. Pp. 28. Southern Forage Plants. Pp. 48. Experiment Station Work—XI. Pp. 32. Notes on Frost. Pp. 24. Experiment Station Work—XII. Pp. 32. Breeds of Dairy Cattle. Pp. 48. Experiment Station Work—XIII. Pp. 32. Saltbushes. Pp. 20. Farmers’ Reading Courses. Pp. 20. Rice Culture in the United States. Pp. 28 Farmers’ Interest in Good Seed. Pp. 24. Bread and Bread Making. Pp. 39. The Apple and How to Grow It. Pp. 82. Experiment Station Work—XIV. Pp. 28. Hop Culture in California. Pp. 27. Trrigation in Fruit Growing. Pp. 48. Sheep, Hogs, and Horses in the Northwest. Pp. 28. Grape Growing in the South. Pp.32. Experiment Station Work—XYV. Pp. 31. Insects Affecting Tobaeco. Pp. 32. Beans and Peas as Food. Pp. 82. Experiment Station Work—XVI. Pp. 32. Red Clover Seed: Information for Pur- chasers. Pp. 11. Experiment Station Work—X VII. Pp. 32. Protection of Food Products from Injurious Temperatures. Pp. 26. Suggestions for Farm Buildings. Pp. 48. Important Insecticides. Pp. 42. Eggsand their Uses as Food. Pp. 32. Sweet Potatoes. Pp. 40. The Mexican Cotton Boll Weevil. Pp. 30. Household Test for Detection of Oleomar- garine and Renovated Butter. Pp. 11. Insect Enemies of Growing Wheat. Pp. 40. Experiment Station Work—XVIII. Pp. 32. Tree Planting in Rural School Grounds. Pp. 38 Sorghum Sirup Manufacture. Pp. 40. Earth Roads. Pp. 24 The Angora Goat. Pp. 48. Irrigation in Field and Garden. Pp. 40. Emmer: A Grain for the Semiarid Regions, Pp. 16. Pineapple Growing. Pp. 48. Poultry Raising on the Farm. Pp. 16. The Nutritive and Economic Value of Food. Pp. 48. The Conformation of Beef and Dairy Cattle. Pp. 44. Experiment Station Work—XIX. Pp. 32. Carbon Bisulphid as an Insecticide. Pp. 28. Insecticides and Fungicides. Pp. 16. Winter Forage Crops for the South. Pp. 36. Celery Culture. Pp. 32. Experiment Station Work—XX. Pp. 32 Clearing New Land. Pp. 24. ath OMe Ney Oe i Wis Tat a ar ay 3 (wei (Oe Lrg SINE TID) SL Abe ieee 7 priv. INSEO1: U. S. DEPARTMENT OF AGRICULTURE. FARMERS’ BULLETIN No. 155. How Insgers Apeect HEALTH IN Rurat Districts. BY L..O. HOWARD, Entomologist. WASHINGTON: GOVERNMENT PRINTING OFFICE, I19go2. LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, Division OF ENTOMOLOGY, Washington, D. C., May 10, 1902. Str: I transmit herewith copy of an article entitled ‘*‘ How Insects Affect Health in Rural Districts,” and have the honor to recommend the publication of the same as a Farmers’ Bulletin. The article was originally prepared by me for the Yearbook for 1901, in which it appears under a different title, but in view of the very general interest in the subject it seems desirable to republish the matter in the pres- ent form for distribution to farmers, to whom, it is believed, the bul- letin will prove of special interest and value. Very respectfully, L. O. Howarp, Entomologist. Hon. JAMES WILson, Secretary of Agriculture. 2 a Introduction - - - - City and country CONT ENS: conditions. compared: 28 . 224 be. <<. ES Pee ewes Samcces Gr ty pho fever. so. 84550 ke res RSS te age ea 2S kabel eee Methods of protection from typhoid and malaria Malaria... .- See ee ee a ee Weviomiy-leanhine Most UGOes ok noses sofas ee wea tees soe eee Breeding places of malaria-bearing mosquitoes .....-.----.--------- Measures to be taken to prevent malaria.............-....--------- Meme OG teet~ aera sad eh eee RT eee hee See ok Net Mees House flies and breeding places... --2-~-22----.0.1222.8._ 2222 22. Measures to be taken to prevent typhoid fever -.-....--...-.-------- J EURUDIIUS au MISTS ps alps ae Dat Sk a a al os aS ho EE a Ma Pace eC Pier Ginesees CATEION DY INSCCts 2 i Seis eee Se oe oe on we eae Yellow fever ILLUSTRATIONS. Hig. 1. Adults of Culex and ‘Anopheles. --s.2 2). he 0 2 oe - ee 2. Anopheles macvlipennts —..025. -- . .2osiedssteeeees Helse eee ee BA RODNCIED CTUCIENS ©. 3 GALA. cnc See ns ao ced akeeeetSeeeReeeees a> eps of Anopheles... 22.55 02 sensi d-anst hb. Coe ee Be a Hoge and Jarya oF Culex 2... 2-.'.-=2>- sso seen ape ee eee ee 6. Pnll-srown larva of Culex. - 22.2.2; - neo ee = ene eee 7 Pull-grown larva of, Anopheles...2212. 052. eset eee 8. Pupa of Culex and Anopheles..: 4 ....-veeec 2 2 ae eee 9. Common house fly ( Musca domestica) ic. 5.5 <2 eb sace eee eee 10; Drosophila ampelophila _.. 2.2). s. -se ee stanc c= ase: >a eee ees i Catjand dog. fles .-. .. 5a2s54.eetens -eepern - 2 eae 12. Cattle tick’ S5.* 205 2osos. f.) ee ee ee eee a3; “Tsetse Wy oss ta see. ; ae Beet eee ek lov cidw ed Seltede eee eee a4. Black gadfly’). os... -os.> .- See Cec se bos epee eee ae oe ee ee 1b eed boe is. 6.25 be ote ots heehee. le ee ee eee 1G. “Stenomypa Pascale. < 2 2 = 232. 283 ee cee eee ae bee 4 HOW INSECTS AFFECT HEALTH IN RURAL DISTRICTS. INTRODUCTION. In very many parts of the country the farming population has to contend with at least two diseases which are preventable. These are malaria and typhoid fever. Both of these diseases are transferred or may be transferred by insects—malaria by certain mosquitoes and typhoid fever by the common house fly, or certain other flies. CITY AND COUNTRY~-CONDITIONS COMPARED. While it is true that both malaria and typhoid prevail in large cities, it is none the less true that they may with a certain degree of accuracy be termed country diseases, that is to say, rather specifically, diseases of the farm and the small village. Malaria, in fact, has been called by medical men a country disease. Swampy regions do not occur in cities, or, at all events, only in the suburbs, whereas they occur com- monly in the country. Open streams with side pools of still water are found only in the country, and it is in such small, still pools, and in more or less permanent but small accumulations of water, that the malarial mosquito breeds. This mosquito, therefore, does not accom- modate itself well to city conditions, but it is found almost everywhere in the country, except possibly in very dry localities and at certain high elevations. Even in dry regions it sometimes abounds, especially where there is a definite rainy season, or where the land is irrigated. Irrigating ditches are prolific breeding places for mosquitoes, includ- ing the malarial kind. Malaria in cities, as a rule, is found only with persons who have contracted it in the country or in the suburbs, although with some cities having marshy places on their borders a malarial belt may exist, the extent of which depends upon the direction and force of the prevailing summer breezes, especially the night breezes. For example, such a condition as this accounts for the prev- alence of malaria in certain portions of the city of Washington before the reclamation of the Potomac Flats, which lie to the south of the city, the prevailing night breezes of the summer being southern. SOURCES OF TYPHOID FEVER. Cities well supplied with water from a reservoir, especially a filter — reservoir, which possess a modern sewage system, and in which water-closets are universal, derive typhoid fever only from the follow- , 5 6 ing sources: Contaminated country milk, the return of people in the autumn from the less sanitary country, and lack of care in the disposal of the discharges of persons who have contracted typhoid from either of the first two sources. In the country, however, conditions are different. Each country house or each house in a small village has its own water supply, usually in the shape of a well; the cattle get water from the streams; there are no water-closets, and excreta are deposited in the open or in box privies; drainage from these box privies or from the open deposits containing virulent typhoid germs may enter the streams, be carried for some distance and be taken into the stomachs of cattle all along the course of the stream, or the germs may be carried by under- ground drainage directly into the wells from which drinking water is gained; or, exposed as these box privies or open deposits are, certain flies may alight upon the excrement and carry the germs directly to the food supply of the houses; or certain flies may breed in this excre- ment and fly, fairly reeking with disease-bearing filth, to the kitchens and tables of nearby houses. When we consider that active typhoid germs may be given out for some time by persons who have not developed typhoid fever sufficiently so that it may be recognized, and that they may also be given out for some time after patients have been apparently cured of the disease, it is perfectly obvious that in the country the lack of care with which excreta are deposited readily accounts for outbreaks of typhoid fever from any of the causes men- tioned. METHODS OF PROTECTION FROM TYPHOID AND MALARIA. Of course it will be said that the entire water supply of a city may become contaminated at or immediately above its reservoir supply. This contamination is from country sources and might be obviated either in a general manner by the establishment of a reservoir filter- ing plant, or in a special manner by individual householders by the constant and thorough use of house filters. In cities possessing a common water supply and modern sanitary plumbing there is no excuse for the presence of typhoid in the household. Even the city water must be filtered, which can be done by the use of any one of the cheap filters now on the market; the milk which is drunk by children must be sterilized, and the excreta of persons returning to the city, after contracting typhoid fever in the country, must be disinfected with the utmost care. These three measures, systematically followed, will result in the abolition of typhoid fever within the city boundaries. So much for cities. In the country the matter is somewhat more difficult, and immunity from malaria and typhoid depends largely upon the individual householder. Such immunity may be obtained, but only as a result of intelligent care. T Let us briefly consider what the farmer or the resident of a small village must do to bring about protection. MALARIA. The old idea that malaria is caused by breathing the miasma of swamps has been exploded. Malaria is contracted only through the . bites of mosquitoes of the genus Anopheles. The cause of human malaria is the growth and development within the red blood cells of a very minute parasitic organism belonging to the lowest group of the animal kingdom—-the group Protozoa, or one-celled animals, which includes those minute creatures known as Amcebas and others, and which live in the water or in damp sands or moss, or inside the bodies of other animals as parasites. This parasite reproduces in the body by subdividing, eventually bursting the red blood cells and entering the blood serum asa mass of spores. Broadly speaking, when the blood of a human being is sucked into the stomach of a mosquito of the genus Anopheles the malarial parasite undergoes a sexual develop- ment and gives birth tq a large number of minute, spindle-shaped cells, known as blasts, which enter the salivary glands of the insect and are ejected with the poison into the system of the next person bitten by the mosquito. If this person happens to be nonmalarious the malaria has thus entered his system and malarial symptoms result. So far as present knowledge goes, this is the only way in which people become malarious. In order to avoid this result it is necessary to avoid the bites of malarial mosquitoes, and it therefore becomes important to know the differences between the malarial and the more harmless mosquitoes, and the conditions under which the malarial forms breed. Malaria-bearing mosquitoes.—There are very many mosquitoes which have not yet been proven to carry any disease. In fact, the majority of mosquitoes are supposed to be harmless except for the irritation caused by their punctures. The commonest of all forms belong to the genus Culex. These include the mosquitoes most commonly breeding in rain-water barrels and chance transient pools. Fig. 1 shows the difference between a harmless mosquito of the genus Culex and the malarious mosquito of the genus Anopheles. It will be noticed that Culex has clear wings, while Anopheles has wings which are more or less spotted. It will be noticed further that while the palpi (which are the projections either side of the beak) are very short in Culex, they are long—nearly as long as the beak—in Anopheles. Further, it has been observed that when Culex is resting upon a wall it appears more or less humpbacked, that is to say, the head and the beak are not in the same plane with the body and wings, but project at an angle toward the surface of the wall, the body and wings being parallel with the wall. With Anopheles, however, the head and beak are in prac- 8 tically the same plane with the body, and the body itself is usually placed at an angle with the wall, and especially when resting upon a b he Fic. 1.—Adults of Culex and Anopheles: a, Culex sollicitans; b, Anopheles punctipennis—enlarged (author’s illustration.) horizontal wall, such as the ceiling of a room, the body of Anopheles is at a very great angle with the surface. We have in this country cy) three species of the malarial genus Anopheles, namely, Anopheles maculipennis (illustrated in fig. 2), Anopheles punctipennis (shown in fio. 1, 6), and Anopheles crucians (shown in fig. 3). The two former are found nearly all over the country, but the last is a more Southern species, although it has been found as far north as the south shore of Long Island. As to the early stages, the eggs of Anopheles may at once be dis- tinguished from the eggs of Culex by figs. 4 and 5, those of Culex being laid in the raft-shaped mass on end and those of Anopheles being laid singly upon the surface of the water, always lying upon their \ Fie. 2.—Anopheles maculipennis: Male at left; female at right—enlarged (author’s illustration). sides. The larve of Culex, commonly known as wigglers, are familiar _ toalmost everyone, and are the common wigglers found in horse troughs and rain-water barrels, which wriggle around in the water, returning at frequent intervals to the surface to breathe, and when at the surface hanging with simply the tip of the tail extruding, the rest of the body being held below the surface at.a great angle. What we have called the ‘“‘tail” is simply the breathing tube, which, with the common Culex wigglers, is long and more or less pointed. With the malarial mosquitoes, however, the wiggler, or larva, is of somewhat different shape, as shown in figs. 6 and 7, and when resting at the surface, which 10 it does most of the time, it lies with its body parallel with the surface, and not hanging down, as does the Culex wiggler. The pup of both forms are shown in fig. 8, and need not be described. Breeding places of malaria-bearing mosquitoes.—The breeding places of the harmless mosquitoes are more numerous and more varied than the breeding places of the malarial mosquitoes. Anopheles, however, are found under many divers conditions. They are found, as stated, in still side pools of small streams, in the swampy pools at the margins of larger ponds, in stagnant water in ditches, in the beds of old canals, ene >~ we ~~ Fie. 3.—Anopheles crucians—enlarged (author’s illustration). in the still water at the sides of springs, and occasionally, though rarely, in old horse troughs. They are perhaps more frequently found in such situations as described when a certain amount of green scum has accumulated, and it is upon the spores of the water plants consti- tuting this green scum, as well as upon other very small objects float- ing on the surface of the water, that they principally feed. Measures to be taken to prevent malaria.—To prevent malarial mos- quitoes from breeding in a given vicinity, one should be prepared to recognize their larvee when they are seen, and to distinguish them from other mosquito larve; then a most thorough search for all possible 11 breeding places should be made within a radius of a mile. This dis- _tance is mentioned, since it seems rather definitely proven that the Anopheles mosquitoes do not fly for great distances. After the breed- ing places are found they should be drained or filled in with earth, or they should be rendered uninhabitable to the Anopheles larve by coy- ering the surface of the water with a thin film of kerosene oil, or by introducing certain fish which feed upon the larve, such as top min- nows, sticklebacks, young sunfish, or goldfish. Pending the result of such exterminating measures, all houses in malarious localities should be carefully screened to prevent the entrance Fie. 4.—Eggs of Anopheles—enlarged (author’s illustration). of mosquitoes. After screening, thorough search should be made in the house for mosquitoes which have already gained eutrance. Such as are found roosting upon the walls should be captured by placing an inverted vial over them, or they may be stupefied by burning a small amount of pyrethrum powder upon a tin-dish cover. Persons wishing to avoid malaria should not sit out of doors exposed to the bites of mosquitoes at night. Persons having malaria should be carefully screened at night to prevent them from being bitten by mosquitoes, which, becoming thus infected, would become potential carriers of the disease. Such patients, systematically treated with quinine, the dose being always given at the beginning of the chill, will soon be rid 12 of the disease. The time of the dose is important, and the reasons for the time have been abundantly proven by the study of the life of the | parasite in the blood cells. All of this advice is given only after abundant demonstration of the efficacy of the methods. These measures have been followed with suc- “cess in the most malarious localities in the world, and with this knowl- edge there is no good reason why an individual should contract malaria in his own home, no matter how much malaria exists around him. Fic. 5.—Eggs and larve of Culex—enlarged (author’s illustration). Of course, hovyever, there may be occasions where it is almost impos- sible to avoid contracting the disease. For example, last October the writer was waiting for a night train one evening in a small Western town where there were irrigating ditches near the station. In these ditches malarial mosquitoes were breeding profusely, and the insects abounded in the station waiting room and on the platform. Nothing but a gauze covering would have kept them away, and several bites were inflicted on the hands and neck. Fortunately, none of the indi- viduals could have bitten a malarial patient, as the disease was not transmitted. TYPHOID FEVER. It is not the writer’s intention to go further into the causation of this disease than he has alread; done in his introductory remarks. He wishes, however, to point out as forcibly as possible the danger of its spread by insects and the methods of avoiding this danger. House flies and breeding places—The principal insect agent in this spread is the common house fly (fig. 9), and this insect is especially ee See eee 13 abundant in country houses in the vicinity of stables in which horses are kept. The reason for this is that the preferred food of the larve of house flies is horse manure. House flies breed in incredible num- bers in a manure pile largely derived from horses. Twelve hundred house flies, and perhaps more, will issue from a pound of horse manure. Ten days completes a generation of house flies in the summer. The number of eggs laid by each female fly averages 120. Thus, under favorable conditions, the offspring of a single over-wintering house _ fly may in the course of a summer reach a figure almost beyond belief. With an uncared-for pile of horse ma- nure in the vicinity of a house, there- fore, flies are sure to swarm. Their i es pin number practically will be limited wae yo only by breeding opportunities. They are attracted to, and will lay their eggs in, human excrement. Under favor- able conditions they will breed, tosome extent, in this excrement. They swarm in kitchens and dining rooms where aye? food supplies are exposed. They are Li 5% found commonly in box privies, which sometimes are not distant from the ye ae kitchens and dining rooms. There- rea fore, with an abundance of flies, with a box privy near by, or with excre- 5 mental deposits in the neighborhood, Lis and with a perhaps unsuspected or not if yet fully developed case of typhoid in — Si the immediate neighborhood, there is ee ao EEN no reason why, through the agency of 2S ~ contaminated flies alighting upon food Ye rN supplies, the disease should not be f) WS spread to healthy individuals. That it ; \ is so spread is not to be questioned. That under the unusual conditions of the army concentration camps in the summer of 1898 it was so spread to a shocking extent has been demonstrated by the army typhoid fever commission. And the remedy is plain. It consists of two courses of procedure: (1) Proper care of excreta; (2) the destruction of flies. Measures to be taken to prevent typhoid fever.—On many farms where intelligent people live the old-fashioned box privy has been done away with, and there has been substituted for it some form of earth closet. Where a good earth closet is in operation, and the inhabitants of a farm appreciate the importance of using no other, and where in case Ae pry oe feee et eres yavara IPM Fig. 6.—Full-grown larva of Culex—en- larged (author’s illustration). 14 of illness the excreta of patients are promptly disinfected, flies nreed- ing in the neighborhood will have practically no opportunity to become contaminated with typhoid germs, except in the unlikely event (which future investigation may possibly show) that other animals than man are subject to this disease. The proper maintenance of an earth closet will add somewhat to the work of a farm, but this extra work will pay in the long run. While it is true contents are covered with lime every three or four days, will answer the pur- pose, a much better plan would be to use a large metal vessel, the surface of the contents being covered | with earth after each opera- tion, and which may be removed, emptied, and re- placed daily. Care should, of course, be taken toempty the contents of the vessel in a pit constructed in some well-chosen spot, from which the drainage would not be dangerous. With regard to the aboli- tion of flies, the best meas- ures will again naturally involve some trouble and expense. In a thickly set- tled country it will become necessarv for some such measure to be generally fectly effective, but in an isolated farmhouse the number of house flies may be greatly reduced by indi- vidual work. AJ] horse manure accumulating in stables or barns should be collected, if not daily, at least once a week, and should be placed in either a pit or vault or in a screened inclosure like a closet at the side or end of the stable. This closet should have an outside door from which horse manure can be shoveled when it is needed for manuring Fic. 7.—Full-grown larva of Anopheles—greatly enlarged (author’s illustration). that a box inclosure, if its — adopted in order to be per- . 15 "h, 4 Pain Heer gn eae od Fic. 9.—Common house fly (Musca domestica): Puparium at left; adult next; larva and enlarged parts at right—enlarged (author’s illustration). Fie. 10.—Drosophila ampelophila: a, adult; b, antenna of same; ec, base of tibia and first tarsal joint of same; d, puparium, side view; e, puparium from aboye; jf, full-grown larva; g, anal spiracles of \ same—enlarged (author’s illustration). 16 purposes. Each day’s or each week’s accumulations, after they are Fic. 11.—Cat and dog flea—enlarged (original). shoveled into the closet or pit, should be sprinkled over the surface with chloride of lime, and a barrel of this substance can conveniently be kept in the closet. If this plan be adopted (and these recommendations are the result of practical experience), house flies will have almost no chance to breed, and their numbers will be so greatly reduced that they will hardly be noticeable. Many experiments have been made in the treatment of manure piles in order to kill the Fic. 12.—Cattle tick—enlarged (redrawn from Salmon and Stiles). maggots of the house fly, and the chloride-of-lime treatment has been found to be the cheapest and most efficacious. It has been stated above that the closet for the re- ception of manure should be made tight to prevent the entrance or exit of flies. A window fitted with a wire screen is not desirable, since the cor- roding chloride fumes will ruin a wire screen in a few days. Fruit flies—While ex- tended investigations have shown that the com- mon house fly is the fly 74 De Fic. 13.—Tsetse fly—enlarged (original). most to be feared in guarding against typhoid, on account of the fact 17 that over 99 per cent of the flies found in kitchens and dining rooms and attracted to food supplies are house flies, there are a few others which are attracted to and which may breed in human excrement that also have to be guarded against, and as these do not breed in horse « manure the treatment just described will not be effective against them. The care of human excrement, however, will prevent the carriage of typhoid germs even by these species. The little fruit flies of the genus Drosophila (fig. 10), which breed in overripe or decaying fruit, are the principal species in this category. Therefore, fruit store- houses or fruit receptacles should be screened, and overripe fruit should not be allowed to remain in dining rooms or kitchens for any length of time. OTHER DISEASES CARRIED BY INSECTS. While in malaria and typhoid we have the two principal diseases common to the United States which may be conveyed by insects, the Fie. 14.—Black gadfly—enlarged (original). biG. 15.—Bedbug—enlarged, (after Marlatt). agency of these little creatures in the transfer of disease germs is much more widespread in warm countries, and it is by no means con- fined to human beings. In Egypt and in the Fiji Islands there is a destructive eye disease of human beings the germs of which are carried by the common house fly. In our Southern States an eye disease known as pink-eye is carried by certain very minute flies of the genus Hippelates. In certain tropical countries a disease known as filariasis, which somewhat resembles certain forms of leprosy, is transferred among human beings by certain mosquitoes. There is good reason to suppose that the germs of the bubonic plague may be transferred from sick people to healthy people by the bites of fleas (fig. 11). The so-called Texas fever of cattle is unquestionably transferred by the common cattle tick (fig. 12), and this was the earliest of the clearly demonstrated cases of the transfer of disease by insects. In 25338—No. 155—02 2 18 Africa a similar disease of cattle is transferred by the bite of the famous biting fly known as the tsetse fly (fig. 13). The germs of the disease of cattle known as anthrax are carried by gadflies, or horse flies, and when these flies subsequently bite human beings malignant pustules may result (see fig. 14 for one of these gadflies); and other discoveries of this nature are constantly being made. Even the com- mon bedbug (fig. 15) is strongly suspected in this connection. YELLOW FEVER. One of the most important of these disease-transfer relations of insects which has been demonstrated is the recently proved carriage of yellow fever by certain mosquitoes. The cause of yellow fever has always been a mys- tery, and indeed it is a mystery to-day in a measure, since al- though undoubtedly a disease of parasitic origin, the parasitic organism itself has not yet been discov- ered. During the summer and autumn of 1900 and spring and summer of 1901 the work of a commission of surgeons of the United States Army has demonstrated in Cuba beyond the slightest possible doubt that yellow fever is not conveyed by infected clothing of yellow-fever patients or by contact with such patients or by proximity to them, but that it is conveyed by the bite of a certain species of mosquito known as Stegomyia fasciata (fig. 16), which abounds in regions where yellow fever is possible. The bite of this mosquito, however, does not convey yellow fever to a healthy per- son until twelve days have elapsed from the time when the same mos- quito has bitten a person suffering with the disease. It follows from this fact that by keeping yellow-fever patients screened from the pos- sibilities of mosquito bites we can prevent the yellow-fever mosquito from becoming infected. It follows further that by preventing healthy people from being bitten by mosquitoes we can keep them free from the disease even where infected mosquitoes exist. And it follows still Fig. 16.—Stegomyia fasciata—enlarged (author’s illustration). 19 further that by the adoption of remedial measures looking toward the destruction in all stages of the yellow-fever mosquito we may reduce to a minimum the possibilities of the transfer of the disease. After demonstrating the fact, the medical officers of the Army in Cuba have put these measures into effect, and the results have been most gratify- ing. The health of Havana has constantly improved, and at the date of present writing the published statement has just been made that during the month of October, 1901, there was not a single case of yellow fever in Havana, while October is usually the severest month for that disease, and in fact during the past ten years the average number of deaths in the city during that month from yellow fever has been 66.27. This discovery, and this practical demonstration of its truth, it seems must soon change all methods of quarantine in the United States; and it seems certain that in the future the Gulf cities will no longer dread the disease or remain subject to the great vital and economic loss to which they have been subject from occasional yellow-fever outbreaks during past generations. FARMERS’ BULLETINS. The following is a list of the Farmers’ Bulletins available for distribution, showing the number and title of each. Copies will be sent to any address on application to any Senator, Representative, or Delegate in Congress, or to the Secretary of Agricul- “ ture, Washington, D. C. ; No. 22. The Feeding of Farm Animals. No, 24. Hog Choleraand Swine Plague. No. 25. Peanuts Culture and Uses. No. 27. Flax for Seed and Fiber. No. 28. Weeds: And How to Kill Them. No. 29. Souring and Other Changes in Milk. No. 30. Grape Diseases on the Pacific Coast. No. 32. Silos and Silage. No.33. Peach Growing for Market. No. 34. Meats: Composition and Cooking. No. 35. Potato Culture. No. 36. Cotton Seed and Its Products. No. 37. Kafir Corn: Culture and Uses. No. 38. Spraying for Fruit Diseases. No. 39. Onion Culture. No. 41. Fowls: Care and Feeding. No. 43. Sew- age Disposal on the Farm. No. 44. Commercial Fertilizers. No. 46. Irrigation in Humid Climates. No. 47. Insects Affecting the Cotton Plant. No. 48. The Manuring of Cotton. No. 49. Sheep Feeding. No. 50. Sorghum as a Forage Crop. No. 51. Standard Varieties of Chickens. No. 52. The Sugar Beet. No. 54. Some Common Birds. No. 55. The Dairy Herd. No. 56. Experiment Station Work—I. No. 57. Butter Making on the Farm. No. 58. The Soy Bean as a Forage Crop. No. 59. Bee Keeping. No. 60. Methods of Curing Tobacco. No. 61. Asparagus Culture. No. 62. Marketing Farm Produce. No. 63. Care of Milk on the Farm. No. 64. Ducks and Geese. No. 65. Experiment Station Work—I1. No.66. Meadows and Pastures. No. 68. The Black Rot of the Cabbage. No. 69. Experiment Station Work—IlII. No. 70. Insect Enemies of the Grape. No. 71. Essentials in Beef Production. No. 72. Cattle Ranges of the Southwest. No. 73. Experiment Station Work—IV. No. 74. Milk as Food. No. 77. The Liming of Soils. No. 78. Experiment Station Work—V. No. 79. Experiment Station Work—VI. No. 80. The Peach Twig-borer. No. 81. Corn Culture in the South. No. 82. The Culture of Tobaceo. No. 83. Tobacco Soils. No. 84. Experiment Station Work—VII. No. 85. Fish as Food. No. 86. Thirty Poisonous Plants. No. 87. Experiment Station Work—VIII. No. 88. Alkali Lands. No. 91. Potato Diseases and Treatment. No. 92. Experiment Station Work—IX No. 93. Sugar as Food. No. 94. The Vegetable Garden. No.95. Good Roads for Farmers. No. 96. Raising Sheep for Mutton. No. 97. Experiment Station Work—X. No. 98. Suggestions to Southern Farmers. No. 99. Insect Enemies of Shade Trees. No.100. Hog Raisingin the South. No. 101. Millets. No.102. South- ern Forage Plants. No. 103. Experiment Station Work—XI. No. 104. Notes.on Frost. No. 105. Experiment Station Work—XII. No. 106. Breeds of Dairy Cattle. No. 107. Experiment Station Work—XIII. No. 108. Saltbushes. No. 109. Farmers’ Reading Courses. No. 110. Rice Culture in the United States. No. 111. Farmers’ Interest in Good Seed. No. 112. Bread and Bread Making. No. 113. The Apple and How to GrowIt. No.114. Experiment Station Work—XIV._ No.115. Hop Cul- turein California. No. 116. Irrigation in Fruit Growing. No. 118. Grape Growing in the South, No. 119. Experiment Stafion Work—XV. No. 120. Insects Affecting Tobacco. No. 121. Beans, Peas, and other Legumes as Food. No.122. Experiment Station Work—XVI. No,123. Red Clover Seed: Infor- mation for Purchasers. No. 124. Experiment Station Work—X VII. No.125. Protection of Food Prod- ucts from Injurious Temperatures. No. 126. Practical Suggestions for Farm Buildings. No, 127. Important Insecticides. No. 128. Eggs and Their Uses as Food. No. 129. Sweet Potatoes. No, 131. Household Tests for Detection of Oleomargarine and Renovated Butter. No. 132. Insect Enemies of Growing Wheat. No. 133. Experiment Station Work—XVIII. No. 134. Tree Planting in Rural School Grounds. No. 135. Sorghum Sirup Manufacture. No, 186. Earth Roads. No. 137. The Angora Goat. No. 138. Irrigation in Field and Garden. No. 139. Emmer: A Grain for the Semiarid Regions. No. 140. Pineapple Growing. No. 141. Poultry Raising on the Farm No. 142. Principles of Nutri- tion and Nutritive Value of Food. No. 143. Conformation of Beef and Dairy Cattle. No. 144. Experiment Station Work—XIX. No. 145. Carbon Bisulphid as an Insecticide. No. 146. Insecticides and Fungicides. No. 147. Winter Forage Crops for the South. No. 148. Celery Culture. No. 149. Experiment Station Work—XX. No. 150. Clearing New Land. No. 151. Dairying in the South. No. 152. Scabies in Cattle. No. 153. Orchard Enemies in the Pacific Northwest. No. 154. The Home Fruit Garden: Preparation and Care. No.155. How Insects Affect Health in Rural Districts. No. 156. The Home Vineyard. No. 157..The Propagation of Plants. No. 158. How to Build Small Irrigation Ditches. No. 159. Scab in Sheep. No. 161. Practical Suggestions for Fruit Growers. No. 162. Experi- ment Station Work—XXI. No. 164. Rape as a Forage Crop. No. 165. Culture of the Silkworm. No. 166. Cheese Making on the Farm. No. 167. Cassava. No. 168. Pearl Millet. No. 169. Experi- ment Station Work—X XII. No. 170. Principles of Horse Feeding. No. 171. The Control of the Cod- ling Moth. No. 172. Scale Insects and Mites on Citrus Trees. No. 173. Primer of Forestry. No. 174. Broom Corn. No.175. Home Manufacture and Use of Unfermented Grape Juice. No. 176. Cranberry Culture. No.177. Squab Raising. No. 178. Insects Injurious in Cranberry Culture. No. 179. Horse- shoeing. No. 181. Pruning. No. 182. Poultry as Food. No. 183. Meat on the Farm—Butchering, Curing, ete. No. 184. Marketing Live Stock. No. 185. Beautifying the Home Grounds. No. 186. Experiment Station Work—XXIII._No.187. Drainage of Farm Lands. No. 188. Weeds Used in Medi- cine. No.190. Experiment Station Work—XXIV. No. 192. Barnyard Manure. No.193. Experiment Station Work—XXV. No.194. AlfalfaSeed. No. 195. Annual Flowering Plants. No. 196. Usetulness of the American Toad. No. 197. Importation of Game Birds and Eggs for Propagation. No. 198. Strawber- ries. No.199. Corn Growing. No. 200. Turkeys. No.201. Cream Separator on Western Farms. No. 202. Experiment Station Work—XXVI. No. 203. Canned Fruits, Preserves, and Jellies. No. 204. The Cultivation of Mushrooms. No. 205. Pig Management. No. 206. Milk Fever and its Treatment. No. 208. Varieties of Fruits Recommended for Planting. No. 209. Controlling the Boll Weevil in Cotton Seed and at Ginneries. No. 210. Experiment Station Work—XXVII. No. 211. The Use of Paris Green in Controlling the Cotton Boll Weevil. No. 212. The Cotton Bollworm—1904. No. 213. Raspberries. No. 214. Beneficial Bacteria for Leguminous Crops. No. 215. Alfalfa in the Eastern States. No. 216. Control of the Cotton Boll Weevil. No. 217. Essential Steps in Securing an Early Crop of Cotton. No. 218. The School Garden. ‘No. 219. Lessons taught by the Grain-Rust Epidemic of 1904. No. 220. Tomatoes. No. 221. Fungous Diseases of the Cranberry. No. 222. Experiment Station Work—X XVIII. No. 223. Miscellaneous Cotton Insects in Texas. No. 224. Canadian Field Peas. No. 225. Experiment Station Work—XXIX. No. 226. Relation of Coyotes to Stock Raising in the West. No. 227. Experiment Station Work—XXX. No. 228. Forest Planting and Farm Manage- ment. No. 229. The Production of Good Seed Corn. No. 230. Game Laws for 1905. No, 231. Spraying for Cucumber and Melon Diseases. No. 232. Okra: Its Culture and Uses. No. 233. Experiment Sta- tion Work—XXXI. No. 234. The Guinea Fowl and Its Use as Food. No. 235. Cement Mortar and Concrete. No. 236 Incubation and Incubators. O — . Issued May 19, 1908, = PEPARIMENT OF AGRICUETURE. FARMERS’ BULLETIN No. 155. How Insects AFFECT HEALTH IN RuraL Districts. LO) HOW ARD: Entomologist and Chtef, Bureau of Entomology. (Revisep Epirion. ) a aq Le, i BN =) WASHINGTON: GOVERNMENT PRINTING OFFICE. 1908. LETTER OF TRANSMITTAL. U. S. DerarTMent oF AGRICULTURE, Bureau or Entomoxoey, Washington, D. C., April 7, 1908. Sir: I have the honor to transmit herewith a revision of Farmers’ Bulletin No. 155, entitled ‘“‘ How Insects Affect Health in Rural Dis- tricts,” and recommend its republication in the present form. The article was originally prepared by me for the Yearbook for 1901, in which it appears under a different title, but in view of the very gen- eral interest in the subject it has seemed desirable to republish the matter for wide distribution to farmers, to whom the information contained in the article is especially pertinent. Respectfully, L. O. Howarp, Entomologist and Chief of Bureau. Hon. James WIixson, Secretary of Agriculture. (2) 155 Introduction CONTENTS. eiy aad country conditions compared <2. 222-22. 52ie.. 2. 2el lo dese ees sace Soeena a tAONOL TOVERE on aioe wc bene Se eet eee Re eee. Methods of protection from typhoid and malaria ......... -....2------------ Malaria - MeletiA-WOATTAS MOSQUITOES ees 29s 2 nes. Saeed SST addetecdss Breeding places of malaria-bearing mosquitoes ....---..-----..----- Measures to be taken to prevent malaria...-.........-.-.----.----- Typhoid RCV Cl eh ete re eee he AS. Sas wale Sees Flouse flies and breeding places ...-.<5. 2.50.46 ec esse ese slab ek Measures to be taken to prevent typhoid fever ...-........-----..--- PNET a ht Oe et SN TK at A ci ceh bce we ate HA fas Prpbiectomitncnved Carrion: DV IMSCCIS 0%. sacs Sento est un ed oot ete. WimilsamtewGn so. ea ca be Se fe oe haw oi te Sena eee raeeerees 155 Fig. cont mS OTe Ww be co 10. 14 12. 13. 14. 15. 16. ILLUSTRATIONS. . Adults of Calex.and’ Anopheles=—- 22 25-0: sat 222 oo. - een noe ee ~ Anopheles *maculipentis .-. < -c -< as sence sete ne rts gee ee = Bee eee . Anopheles crucians .. ges of Anopheles: 2..5- Ss 200 Sos ce oot cee Se ee eee . goes and Jarvee of Calex 2 222d: ean 823 eee eee . ball-erown larva ‘of Culex. 5. ccs can ood feeb os eee eee eee Cat and dog flea - Cattle tick .....- Tsetse fly ....-.- Bedbumses2ss.:5 155 , Bull-erown lanra.of Anopheles’: ..:..- > 3-s3.02. tee = a2 eee . Pups of Calex and Anopheles: <> 2-22 S42.6. es. Soh se. see . Conimon house fy ( Musca domestica) 22<./: S222. 23. gees ee Drosophila ampelophila) x. o20 3 ses t2e25. 05-26 Pe os eee HOW INSECTS AFFECT HEALTH IN RURAL DISTRICTS. INTRODUCTION. In very many parts of the country the farming population has to contend with at least two diseases which are preventable. These are malaria and typhoid fever. Both of these diseases are transferred or may be transferred by insects—malaria by certain mosquitoes and typhoid fever by the common house fly, or certain other flies. CITY AND COUNTRY CONDITIONS COMPARED. While it is true that both malaria and typhoid prevail in large cities, it is none the less true that they may with a certain degree of accuracy be termed country diseases, that is to say, rather specific- ally, diseases of the farm and the small village. Malaria, in fact, has been called by medical men a country disease. Swampy regions do not occur in cities, or, at all events, only in the suburbs, whereas they occur commonly in the country. Open streams with side pools of still water are found only in the country, and it is in such small, still pools, and in more or less permanent but small accumulations of water, that the malarial mosquito breeds. This mosquito, therefore, does not accommodate itself well to city conditions, but it is found almost everywhere in the country, except possibly in very dry locali- ties and at certain high elevations. Even in dry regions it sometimes abounds, especially where there is a definite rainy season, or where the land is irrigated. Ivrrigating ditches are prolific breeding places for mosquitoes, including the malarial kind. Malaria in cities, as a rule, is found only with persons who have contracted it in the country or in the suburbs, although with some cities having marshy places on their borders a malarial belt may exist, the extent of which de- pends upon the direction and force of the prevailing summer breezes, especially the night breezes. For example, such a condition as this accounts for the prevalence of malaria in certain portions of the city of Washington before the reclamation of the Potomac Flats, which lie to the south of the city, the prevailing night breezes of the sum- mer being southern. 155 (5) 6 SOURCES OF TYPHOID FEVER. Cities well supplied with water from a reservoir, especially a filter reservoir, which possess a modern sewage system, and in which water-closets are universal, derive typhoid fever only from the follow- ing sources: Country milk contaminated through vessels washed in water infected with typhoid germs, the return of people in the au- tumn from the less sanitary country, and lack of care in the disposal of the discharges of persons who have contracted typhoid from either of the first two sources. In the country, however, conditions are different. Each country house or each house in a small village has its own water supply, usu- ally in the shape of a well; there are few water-closets, and excreta are deposited in the open or in box privies; drainage from these box privies or from the open deposits containing virulent typhoid germs may enter the streams, or the germs may be carried by underground drainage directly into the wells from which drinking water is gained ; or, exposed as these box privies or open deposits usually are, certain flies may alight upon the excrement and carry the germs directly to the food supply of the houses; or certain flies may breed in this excrement and fly, fairly reeking with disease-bearing filth, to the kitchens and tables of nearby houses. When we consider that active typhoid germs may be given out for some time by persons who have not developed typhoid fever sufficiently so that it may be recognized, and that they may also be given out for some time after patients have been appar- ently cured of the disease, it is perfectly obvious that in the country _ the lack of care with which excreta are deposited readily accounts for outbreaks of typhoid fever from any of the causes mentioned. METHODS OF PROTECTION FROM TYPHOID AND MALARIA. Of course it will be said that the entire water supply of a city may become contaminated at or immediately above its reservoir supply. This contamination is from country sources and might be obviated either in a general manner by the establishment of a reservoir filter- ing plant, or in a special manner by individual householders by the constant and thorough use of house filters. In cities possessing a common water supply and modern sanitary plumbing there is no excuse for the presence of typhoid in the household. Even the city water must be filtered, which can be done by the use of any one of the cheap filters now on the market; the milk which is drunk by children must be sterilized, and the excreta of persons returning to the city, after contracting typhoid fever in the country, must be disinfected with the utmost care. These three measures, systematically followed, will result in the abolition of typhoid fever within the city bound- aries. 155 7 So much for cities. In the country the matter is somewhat more difficult, and immunity from malaria and typhoid depends largely upon the individual householder. Such immunity may be obtained, but only as a result of intelligent care. Let us briefly consider what the farmer or the resident of a small village must do to bring about protection. MALARIA. The old idea that malaria is caused by breathing the miasma of swamps has been exploded. Malaria is contracted only through the bites of mosquitoes of the genus Anopheles. The cause of human malaria is the growth and development within the red blood cells of a very minute parasitic organism belonging to the lowest group of the animal kingdom—the group Protozoa, or one-celled animals, which includes those minute creatures known as Amcebas and others, and which live in the water or in damp sands or moss, or inside the bodies of other animals as parasites. This parasite reproduces in the body by subdividing, eventually bursting the red blood cells and entering the blood serum as a mass of spores. Broadly speaking, when the blood of a human being is sucked into the stomach of a mosquito of the genus Anopheles the malarial parasite undergoes a sexual devel- opment and gives birth to a large number of minute, spindle-shaped cells, known as blasts, which enter the salivary glands of the insect and are ejected with the poison into the system of the next person bitten by the mosquito. If this person happens to be nonmalarious the malaria has thus entered his system and malarial symptoms result. So far as present knowledge goes this is the only way in which people become malarious. In order to avoid this result it is necessary to avoid the bites of malarial mosquitoes, and it therefore becomes important to know the differences between the malarial and the more harmless mosquitoes, and the conditions under which the malarial forms breed. Malaria-bearing mosquitoes.—There are very many mosquitoes which have not yet been proven to carry any disease. In fact, the majority of mosquitoes are supposed to be harmless except for the irritation caused by their punctures. The commonest of all forms belong to the genus Culex. These include the mosquitoes most commonly breeding in rain-water barrels and chance transient pools. Fig. 1 shows the difference between a harmless mosquito of the genus Culex and the malarious mosquito of the genus Anopheles. It will be noticed that Culex has clear wings, while Anopheles has wings ‘which are more or less spotted. It will be noticed further that while the palpi (which are the projections either side of the beak) are very short in Culex, they are long—nearly as long as the beak—in Anopheles. Further, 155 Fig. 1.—Adults of Culex and Anopheles: a, Culex sollicitans ; b, Anopheles punctipennis. (author's illustra- it has been ob- served that when Culex is resting upon a wall it ap- pears more or less humpbacked, that is to say, the head and the beak are not in the same plane with the body and _ wings, but project at an angle toward the surface of the wall, the body and wings being par- allel with the wall. With Anopheles, however, the head and beak are in practically the same plane with the body, and the body itself is usually placed at an angle with the wall, and especially when resting upon a hor- izontal wall, such as the ceiling of a room, the body of Anopheles is at a very great angle with the surface. We have in this country three spe- cies of the mala- rial genus Ano- pheles, namely, Anopheles maculi- pennis (illustrated in fig. 2), Ano- pheles punctipen- nis (shown in fig. 1, 6), and Ano- 9 pheles crucians (shown in fig. 3). The former two are found nearly all over the country, but the last is a more Southern species, although it has been found as far north as the south shore of Long Island. : As to the early stages, the eggs of Anopheles may be at once dis- tinguished from the eggs of Culex by figs. 4 and 5, those of Culex being laid in the raft-shaped mass on end and those of Anopheles being laid singly upon the surface of the water, always lying upon their sides. The larve of Culex, commonly known as wigglers, are Fic. 2.—Anopheles maculipennis: Male at left; female at right. Enlarged (author’s illustration). familiar to almost everyone, and are the common wigglers found in horse trougns and rain-water barrels, which wriggle around in the water, returning at frequent intervals to the surface to breathe, and when at the surface hanging with simply the tip of the tail extruding, the rest of the body being held below the surface at a great angle. What we have called the “ tail ” is simply the breathing tube, which, with the common Culex wigglers, is long and more or less pointed. With the malarial mosquitoes, however, the wiggler, or larva, is of somewhat different shape, as shown in figs. 6 and 7, and when resting 39022—Bull. 155—08 2 10 at the surface, which it does most of the time, it lies with its body parallel with the surface, and not hanging down, as does the Culex wiggler. The pupe of both forms are shown in fig. 8, and need not be described. : Breeding places of malaria-bearing mosquitoes—The breeding places of the harmless mosquitoes are more numerous and more varied than the breeding places of the malarial mosquitoes. Anopheles, however, are found under many diverse conditions. They are found, as stated, in still side pools of small streams, in the swampy pools at the margins ae Fic. 3.—Anopheles crucians. Enlarged (author’s illustration). of larger ponds, in stagnant water in ditches, in the beds of old canals, | in the still water at the sides of springs, and occasionally, though rarely, in old horse troughs. They are perhaps more frequently found in such situations as described when a certain amount of green scum has accumulated, and it is upon the spores of the water plants consti- tuting this green scum, as well as upon other very small objects float- ing on the surface of the water, that they principally feed. Measures to be taken to prevent malaria.—To prevent malarial mos- quitoes from breeding in a given vicinity, one should be prepared to 155 11 recognize their larvee when they are seen, and to distinguish them from other mosquito larve; then a most thorough search for all pos- sible breeding places should be made within a radius of a mile. This distance is mentioned, since it seems rather definitely proven that the Anopheles mosquitoes do not fly for great distances. After the breed- ing places are found they should be drained or filled in with earth, or they should be rendered uninhabitable to the Anopheles larve by cov- ering the surface of the water with a thin film of kerosene oil, or by introducing certain fish which feed upon the larve, such as top min- nows, sticklebacks, young sunfish, or goldfish. Fic. 4.—Eggs of Anopheles. Enlarged (author's illustration). Pending the result of such exterminating measures, all houses in malarious localities should be carefully screened to prevent the en- trance of mosquitoes. After screening, thorough search should be made in the house for mosquitoes which have already gained entrance. Such as are found roosting upon the walls should be captured by placing an inverted vial over them, or they may be stupefied by burn- ing a small amount of pyrethrum powder upon a tin dish cover. Per- sons wishing to avoid malaria should not sit out of doors exposed to 155 12 the bites of mosquitoes at night. Persons having malaria should be carefully screened at night to prevent them from being bitten by mos- quitoes, which, becoming thus infected, would become potential car- riers of the disease. Such patients, systematically treated with quinine, the dose being always given at the beginning of the chill, will soon be rid of the disease. The time of the dose is important, and the reasons for the time have been abundantly proven by the study of the life of the parasite in the blood cells. All of this advice is given only after abundant demonstration of the efficacy of the methods. These measures have been followed with success in the most malarious localities in the world, and with this knowledge there is no good reason why an individual should contract Fic. 5.—Eggs and larve of Culex. Enlarged (author's illustration). malaria in his own home, no matter how much malaria exists around him. Of course, however, there may be occasions where it is almost impossible to avoid contracting the disease. For example, the writer was once waiting for a night train one evening in a small Western town where there were irrigating ditches near the station. In these ditches malarial mosquitoes were breeding profusely, and the insects abounded in the station waiting room and on the plat- form. Nothing but a gauze covering would have kept them away, and several bites were inflicted on the hands and neck. Fortunately, none of the individuals could have bitten a malarial patient, as the disease was not transmitted. 155 13 TYPHOID FEVER. Tt is not the writer’s intention to go further into the causation of this disease than he has already done in his introductory remarks. He wishes, however, to point out as forcibly as possible the danger of its spread by insects and the methods of avoiding this danger. House flies and breeding places.—The principal insect agent in this spread is the common house fly (fig. 9), and this insect is especially abundant in country houses in the vicinity of stables in which horses are kept. The reason for this is that the preferred food of the larve of house flies is horse manure. House Ey, ey flies breed in incredible numbers in eo W/ a manure pile largely derived from “pee horses. Twelve hundred house flies, Cee. WY and perhaps more, will issue from a SX AL pound of horse manure. Ten days completes a generation of house flies — . ex in the summer. The number of eggs - A AY \ ay — laid by each female fly averages 120. PIES Thus, under favorable conditions, the offspring of a ‘single over-wintering | house fly may in the course of a summer reach a figure almost beyond belief. With an uncared-for pile of horse manure in the vicinity of a house, therefore, flies are sure to swarm. Their number practically will be limited only by breeding op- portunities. They are attracted to, and will lay their eggs in, human excrement. Under favorable condi- tions they will breed, to some extent, in this excrement. They swarm in kitchens and dining rooms where F1¢. 6—Full-grown larva of Culex. food supplies Aes exposed. They ae Enlarged (author’s illustration). found commonly in box privies, which sometimes are not distant from the kitchens and dining rooms. Therefore, with an abundance of flies, with a box privy near by, or with excremental deposits in the neighborhood, and with a perhaps unsuspected or not yet fully developed case of typhoid in the immediate neighborhood, there is no reason why, through the agency of contaminated flies alighting upon food supplies the disease should not be spread to healthy individuals. That it is so spread is not to be questioned. That under the unusual conditions of the army concentration camps 155 - 14 in the summer of 1898 it was so spread to a shocking extent has been demonstrated by the army typhoid fever commission. And the rem- edy is plain. It consists of two courses of procedure: (1) Proper care of excreta; (2) the destruction of flies. Measures to be taken to prevent typhoid fever. —On many farms where intelligent people live the old-fashioned box privy has been Fic. 7.—Full-grown larva of Anopheies. Greatly enlarged (author's illustration). done away with, and there has been substituted for it some form of earth closet. Where a good earth closet is in operation, and the inhabitants of a farm ap- preciate the importance of using no other, and where in case of illness the excreta of patients are promptly disinfected, flies breeding in the neighbor- hood will have practically no opportunity to become contaminated with typhoid germs, except in the un- likely event (which future investigation may possibly show) that other animals than man are subject to this disease. The proper maintenance of an earth closet will add somewhat _ to the work of a farm, but this extra work will pay in the long run. While it is true that a box inclosure, if its contents are covered with lime every three or four days, will answer the purpose, a much _ better plan would be to use a large metal vessel, the sur- face of the contents being covered with earth after each operation, and which may be removed, emptied, and replaced daily. Care should, of course, be taken to empty the contents of the vessel in a pit constructed in some well- chosen spot, from which the drainage would not be dangerous. 155 15 With regard to the abolition of flies, the best measures will again naturally involve some trouble and expense. In a thickly settled country it will become necessary for some such measure to be gener- ally adopted in order to be perfectly effective, but in an isolated farm- Fie. 8.—Pupa of Culex (at left) and Anopheles (at right), jreatly enlarged (author’s illustration). house the number of house flies may be greatly reduced by individual work. All horse manure accumulating in stables or barns should be collected, if not daily, at least once a week, and should be placed in either a pit or vault or in a screened inclosure like a closet at the side or end of the stable. This closet should have an outside door from Fic. 9.—Common house fly (Musca domestica) : Puparium at left; adult next; larva and enlarged parts at right. Enlarged (author’s illustration). which horse manure can be shoveled when it is needed for manuring purposes. Each day’s or each week’s accumulations, after they are shoveled into the closet or pit, should be sprinkled over the surface with chloride of lime, and a barrel of this substance can conveniently be kept in the closet. If this plan be adopted (and these recommen- 155 16 dations are the result of practical experience), house flies will have almost no chance to breed, and their numbers will be so greatly re- duced that they will hardly be noticeable. Many experiments have been made in the treatment of manure piles in order to kill the mag- gots of the house fly, and the chloride-of-lime treatment has been found to be the cheapest and most efficacious. It has been stated above that the closet for the reception of manure should be made tight to prevent the entrance or exit of flies. A win- dow fitted with a wire screen is not desirable, since the corroding chloride fumes will ruin a wire screen in a few days. Fruit flies—While extended investigations have shown that the common house fly is the fly most to be feared in guarding against typhoid, on account of the fact that over 99 per cent of the flies found Fic. 10.—Drosophila ampelophila: a, Adult; b, antenna of same; e, base of tibia and first tarsal joint of same; d, puparium, side view; e, puparium from above; f, full-grown larva; g, anal spiracles of same. Enlarged (author's illustration). in kitchens and dining rooms and attracted to food supplies are house flies, there are a few others which are attracted to and which may breed in human excrement that also have to be guarded against, and as these do not breed in horse manure the treatment just described will not be effective against them. The care of human excrement, however, will prevent the carriage of typhoid germs even by these species. The little fruit flies of the genus Drosophila (fig. 10), which breed in overripe or decaying fruit, are the principal species in this category. Therefore, fruit storehouses or fruit receptacles should be screened, and overripe fruit should not be allowed to remain in dining rooms or kitchens for any length of time. OTHER DISEASES CARRIED BY INSECTS. While in malaria and typhoid we have the two principal diseases common to the United States which may be conveyed by insects, the 165 17 agency of these little creatures in the transfer of disease germs is much more widespread in warm countries, and it is by no means con- fined to human beings. In Egypt and in the Fiji Islands there is a destructive eye disease of human beings the germs of which are carried by the common house fly. In our Southern States an eye disease known as pink-eye is carried by certain very minute flies of the genus Hippelates. In certain tropi- cal countries a disease known as filariasis, which somewhat resem- bles certain forms of leprosy, is transferred among human beings by certain mosquitoes. There is good reason to suppose that the germs of the bubonic plague may be transferred from sick people to healthy people by the bites of fleas (fig. 11). The so-called Texas fever of cattle is unquestionably ance ferred by the common cattle tick (fig. 12), and this was the earliest of the clearly demonstrated cases of the transfer of disease by insects. In Africa a similar disease of cattle is transferred by the bite of the famous biting fly known as the tsetse fly (fig. 13) and the so-called Fie. 11.—Cat and dog flea. Enlarged (original). Fic. 12.—Cattle tick. Enlarged (redrawn from Salmon and Stiles). “ sleeping sickness ” of human beings is conveyed by the same insect. The germs of the disease of cattle known as anthrax are carried by gadflies, or horse flies, and when these flies subsequently bite human beings malignant pustules may result (see fig. 14 for one of these gadflies) ; and other discoveries of this nature are constantly being 155 18 made. Even the common bedbug (fig. 15) is strongly suspected in this connection. YELLOW FEVER. One of the most important of these disease-transfer relations of of” ; Fic. 18.—Tsetse fly. Enlarged (original). insects which has been demonstrated is the car- riage of yellow fever by certain mosquitoes. The cause of yellow fever has always been a mystery, and indeed it is a mystery to-day in a measure, since, al- though undoubtedly a disease of parasitic origin, the _ parasitic organism itself has not yet been discovered. During the summer and autumn of 1900 and spring and summer of 1901 the work of a com- mission of surgeons of the United States Army demonstrated in Cuba beyond the slightest possible doubt that yellow fever is not conveyed by infected clothing of yellow-fever patients or by contact Fic. 14.—Black gadfly. Enlarged (ori- 1G. 15.—Bedbug. Hnlarged (after Mar- ginal). latt). with such patients or by proximity to them, but that it is conveyed by the bite of a certain species of mosquito known as Stegomyia 155 —————— 19 calopus (fig. 16), which abounds in regions where yellow fever is possible. The bite of this mosquito, however, does not convey yellow fever to a healthy person until twelve days have elapsed from the time when the same mosquito has bitten a person suffering with the disease. It follows from this fact that by keeping yellow-fever patients screened from the possibilities of mosquito bites we can prevent the yellow-fever mosquito from becoming infected. It fol- lows further that by preventing healthy people from being bitten by mosquitoes we can keep them free from the disease even where infected mosquitoes . exist. And it fol- lows still further that by the adoption of remedial measures looking toward the destruction in all stages of the yellow- fever mosquito we may reduce to a min- imum the possibili- ties of the transfer of the disease. After demonstrating the fact, the medical offi- cers of the Army in Cuba put these meas- ures into effect, and _ the results were most gratifying. The health of Havana immediately im- proved, and the general health of Cuba and the industrial conditions dependent upon better sanitation have continually gained since. The New Orleans outbreak of yellow fever in the summer of 1905 was quickly stopped by antimosquito measures, and it is conceded that more than 4,000 lives were saved in that city during that season by the intelligent application of measures based upon the discovery of the United States Army surgeons in Cuba in 1900 and 1901. 155 J Fic. 16.—Stegomyia calopus. Enlarged (author’s illustra- tion). O | U.S, DEPARTMENT OF AGRICULTURE, FARMERS’ BULLETIN No. 163. METHODS OF CONTROLLING THE BOLL WEEVIL, [Advice based on the work of 1902.] W. D. HUNTER, SPECIAL FIELD AGENT. 5 ctieeny ay é : SN sel CRE aaa un Ee Riss = SE= — WASHINGTON: GOVERNMENT PRINTING OFFICE 185 897G 1903. vu LETTER OF TRANSMITTAL. U. 8S. DeparTMENT OF AGRICULTURE, Division oF EnromoLoey, Washington, D. C., January 6, 1903. Sie: J transmit with this a brief manuscript by Mr. W. D. Hunter, a special agent of this Division in charge of experimental work with the Mexican cotton boll weevil (Anthonomus grandis). I have examined this manuscript and warmly approve of its recommenda- tions. J urge its immediate publication as a Farmers’ Bulletin. Respectfully, L. O. Howarp, Entomologist. Hon. James WIitson, Secretary of Agriculture. CONTENTS. “uu ERRNO LOEUG Lay At ER ee ay re Me Ps. Sp aR a an pe ee ER I ene eee Re eee Mie ES As eben oa Case ck osu eutce aeamemd ieee ERR ee eel ek Se ee koe pee cceh od tn ck ece oe paces HIE pNOSPEetss. = 525 Lae srceces se 52 Pease een Tee yee eaten Aya ERE oh mae ae me ean eT E LIN. hehe dos cae kc ch ate sokn Sos ahoene ee nuseueembese om Ineffective methods of combating the boll weevil ...............------------ Nl Shs 0 a RRR Sa el el See Reg ce eae Wee aoe 8 Peas cotcon andthe: boll weevil... 2255.46 oDed son dess ond dass see Sebeee Ree eer cnmilaeneraihitias = (5.00) oe hh So aa deten ad adeninenicaien se eeaad of ILLUSTRATIONS. Fia. 1.—Map showing the cotton-growing area and the weevil-infested area ae Pry,’ 2.--Experimental cotton fields. -. -. 222. sac caccnscccenesscce + ondanmes 4 METHODS OF CONTROLLING THE BOLL WEEVIL. INTRODUCTORY. The Division of Entomology has worked with the boll weevil since the first appearance of the pest in Texas in 1894. Up to the present time practically continuous observations have been made upon its natural history, habits, and the means by which it reaches new regions; and the results of these observations, with suggestions regarding the manner of combating the pest, drawn from them and from the experi- ence of many planters, have already been published. It was not, however, until the last season that the funds at the disposal of the Division permitted experimental field work on a considerable scale. By special appropriation, which became available on the 4th of June, 1902, it became possible for the Division to conduct field work on a large scale and according to a system that gives tangible and present- able results. The arrangement consists of a contract whereby certain planters agree to plant, cultivate, and care for the crop exactly in accordance with the directions of the agent of the Division. It conse- quently gives the Division practically complete charge of large tracts of cotton in typical situations without involving the labor and expense of renting the land and working the crop. In this way 200 acres at Calvert and 150 acres at Victoria, Tex,, were used for experimental purposes. A complete field laboratory was established at the latter place for rearing work, breeding parasites, and testing poisons, as well as investigating every feature of the life history of the weevil that may afford any advantage in fighting the pest. Though somewhat handicapped by the late date at which the appro- priation became available, the work of the past season has demon- strated many important points. The principal ones are presented in the following pages, together with such previously acquired informa- tion as constitutes, it is believed, the basis of a practical and effective system of producing the staple anywhere that the boll weevil occurs. TERRITORY AFFECTED. Though still confined to Texas, the territory occupied by the cotton- boll weevil (Anthonomus grandis Boh.) at present includes abcut 28 per cent of the cotton acreage in the United States. This acreage in a) or one- As will be seen from bounded on the north 1900 produced 34 per cent of the total crop of this country, fourth of the crop of the world for that year. this region is 1), g. the accompanying map (fi BL VIYY OMMOYINOLLOD he 5 Tat é. CG ; : MOLENXTT ZA -by the Red River and on the east by the pine forests of the divide It includes all of the 22 coun- ties, which, in 1899, according to the Twelfth Census, produced between the Trinity and Sabine rivers. 7 40,000 bales or more each. In the newly invaded region, however, between the latitude of Dallas and the Red River, the insect, though seatteringly present, has not multiplied to such an extent as to cause much damage. AMOUNT OF DAMAGE. Various estimates of the loss occasioned to the cotton. planters dur- ing the past year have been made. They range from 235,000 to 500,000 bales, representing from 8 to 25 millions of dollars. In the nature of the case, such estimates must be made upon data difficult to obtain, and in the collection of which many errors must inevitably occur. As is well known, there is a general tendency to exaggerate agricultural losses, as well as to attribute to a single factor damage that is the result of a combination of many influences. Before the advent of the boll weevil into Texas, unfavorable weather at planting time, summer drought, and heavy fall rains, as well as the attack of many other noxious insects, caused very light crops to be produced. Now, however, the tendency is to attribute all of the shortage to the weevil. Nevertheless, not only on account of the very serious work of the insect, but also on account of the rather unfortunate previous condition of the cotton-producing industry, the boll weevil is among the most formidable menaces to an agricultural industry that ever arose in this country or elsewhere. It seems well within the bounds of conservatism to state that during 1902 the insect caused Texas a loss of at least 10 millions of dollars. In spite of the generally serious outlook, it must be stated that fears of the damage the weevil may do are often, especially in a newly invaded district, very much exaggerated. It is by no means necessary to abandon cotton. The Division of Entomology has demon- strated the past season that the crop can be grown profitably in spite of the boll weevil. Moreover, the experience of many counties in south Texas shows how a locality can, in a short time, adapt itself to the new system of cotton raising made necessary by the weevil. The experience of Victoria County illustrates this point well. The fol- lowing table shows the production of cotton since the advent of the boll weevil. No accurate statistics of acreage are available, but it is the uniform testimony of the most reliable planters that the acreage has not been increased very materially. Cotton production in Victoria County, Tex., and in the United States, in equivalents of 500-pound bales. ; ; Crop of | Crop of Crop of | Crop of Year. Victoria | United Year: Victoria | United County. | States. County. | States. Millions Millions : Bales. | of bales. Bales. | of bales. RGA cya blajaiche aiatain atnleie) nists aiais States 6, 895 DE LO Shi eccratoterks cistetalo'breratavai'u stale tiw\e Sere 7, 006 12,L WOO ae= Se cake eee eehe woees 4, 404 Lise | es eee aes re Ee eee a ae 5, 547 9.9 MU sacra ence oe cciete caters 9,796 2a I [oll (S19 a SR AR renee nee 11, 956 li.i 2 OS eis SRS Ob eee eres ees 7,746 ras aa beets ercarcuerciete tee ere imatebs oie atte 9, 060 9.5 8 Besides showing in general a successful continuation of cotton cul- ture in Victoria County since the weevil reached it, the above table indicates that the crop of the United States at large has varied year by year in much the same way as has the crop of Victoria County, show- ing that climatic conditions affecting the entire cotton belt have been a much more important factor than the weevil in reducing the crop in a series of years. FUTURE PROSPECTS. The most serious aspect of the situation is in the fact that the pest is constantly spreading and will undoubtedly eventually be distributed all over the cotton belt. Thereare no influences that can check it short of the limit of its food plant in this country. In Mexico, where the insect has existed as an important enemy of cotton for a much longer period than in the United States, the investigations of the Division of Entomology, as well as of the Mexican Government, indicate that the only factor in limiting its distribution is that of altitude. In the famous ‘‘ Laguna” district in that country, including portions of the States of Coahuila, Chihuahua, and Durango, the weevil has never gained a foothold, notwithstanding the fact that large quantities of seed cotton are annually shipped there for ginning and milling from the lower region, where it is very numerous. That this‘region, under these circumstances, has never become infested seems only to be explained by its altitude, which is disastrous to an insect which prob- ably originated in a region of very low elevation. The average eleva- tion of the ‘“‘Laguna” district is about 3,500 feet above sea level. Unfortunately, in this country there is no land at all adapted to cot- ton culture in the belt as now constituted that approaches such an elevation. Basing the estimate on a careful study of the annual increase in ter- ritory since the insect reached Texas, as well as upon considerable atten- tion that has been paid to the means whereby it reaches new territory, it seems safe to predict that in from fifteen to eighteen years the pest will be a serious drawback to cotton culture everywhere throughout the South, as it is in Texas now. METHODS OF COMBATING. It is wholly beyond possibility that the weevil is ever to be exter- minated. Its history in Mexico and since reaching Texas, as well as the history of many related injurious insects, offers no hope that it will ever be much less destructive than now. Nevertheless, it has been demonstrated that cotton can be grown profitably by means of a few expedients in planting and managing the crop where the insect is present. These expedients involve no appreciable extra expense in producing the staple, and accordingly are coming to be generally 9 \ adopted in preference to direct means, such as poisons and machines, which, aside from their doubtful utility under many conditions, involve expenses for labor or material that soon hopelessly reduce the margin of profit. During the past season the Division of Entomology has been engaged in field experiments to demonstrate that cotton can be produced suc- cessfully in spite of the boll weevil. Some of this work was conducted on the plantation of Col. E. S. Peters, in the Brazos Valley, near Cal- vert, Texas. This valley is, on account of its low and moist situation, the presence of timber, and the almost exclusive production of cot- ton, the most seriously affected portion of the weevil territory. In fact, the most favorable conditions possible for the multiplication of the insect are there present, and Colonel Peters’s plantation is a typical one. The accompanying diagram (fig. 9) shows the location of some of the experimental fields. The soil is the typical alluvial deposit of the valley and practically identical throughout the 128 acres included in this experiment. The seed was the ordinary seed of the region, grown on the same plantation the year before, of an unknown variety, as is usually the casein that region. The stand was equally good everywhere. No means of fighting the weevil whatever, aside from those mentioned, were practiced. In none of the fields did any other insects, aside from the weevil, cause any considerable injury. The bollworm was _pres- ent, but did very little damage; the sharpshooter was scarcely noticed; and the leaf worm did not appear in sufficient numbers to warrant poisoning. To summarize the results of these experiments: 1. Early planted cotton with thorough cultivation produced two- thirds of a bale per acre. 9. Early planted cotton with careless cultivation produced onc- ninth of a bale per acre. 3. Early planted cotton with fair cultivation produced one-half bale per acre. 4, Late planted cotton with wide rows yielded about one-fourth of a bale per acre. 5. Late planted cotton with narrow rows, sprayed thoroughly, yielded about one-fourth of a bale per acre. The evident conclusions are: First. A profitable crop in the most unfavorable situation can be produced by early planting and thorough cultivation, as in Iield I (fig. 2). This field produced one bale to 1.5 acres; the average pro- duction in the United States is one bale to 2.3 acres. The experiment, moreover, was performed during probably the most generally disas- trous season for cotton culture in Texas for twenty-five years. 10 R Ares, | well worked [plowed SS Yel 3936 lbs. lint or s 328 lis per acre. JO Acres, rows 6 feet bone best cullvatior. Jield 652 lis lint or 130.62lbs per =) 8 Acres, are. ~ worked out late; . Re : & or 243.125 lbs per. i JO ACTES, rows 4 feelapart, best cullwa- ton; thoroughly sprayed. Jield 6613 lbs.link or 132.26 lbs per acre. Fic. 2.—Experimental cotton fields. Norre.—Although the field of 50 acres with the rows 6 feet apart yielded less lint than the field of 50 acres with the rows 4 feet apart, the margin of profit was greater on the former on account of the saving in chopping. A tabular statement follows: Yield on 50.acres' with rowsi4 feet apart: ¢i--- 352. 2- eee ese es pounds.. 6,613 Yield on 50 acres with rows:6 feet apart .... .222ccc- < 22225 Sense cece ews -eeienes soe een SaeeE eee 4 165 — EEE DLR WORM CULTURE: The caterpillars of many moths and of a few butterflies produce silk, but certain of those belonging to the family Bombycidae, or true silk- spinners, particularly Bombyx (Sericaria) mort, or the mulberry silk- worm, yield the most and the best silk. The races of Bombyx mori to-day are the result of domestication and artificial rearing, and the wild type is uncertain, though most authorities assign the foot of the Himalaya as the cradle of the mulberry silkworm. It has been indus- trially cultivated in China from time immemorial, and in Europe since the sixth century. THE LIFE OF THE SILKWORM. Like all insects of its class, before arriving at the perfect winged state, it exists (1) as a caterpillar or larva, and (2) in a chrysalis state. $ Os AL “ 19 > sanne wenn SS mens eoeee == 8) NI R 13 Ig” Is- Fie. 1.—Adult silkworm: 1, head; 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, rings; 11, horn; 13, 3 pairs of articulated legs; 14, 4 pairs of abdominal or false legs; 15, a pair of false legs on the last ring. THE LARVA, OR CATERPILLAR. The larva (fig. 1) has a cylindrical body composed of 12 rings; each of the first three has a pair of jointed legs, and the sixth, seventh, eighth, ninth, and twelfth each bears a pair of false legs, destined later to disappear. The black elliptical spots on the side are the orifices for breathing, and are called stigmata or spiracles. The head is a small mass covered with a hard scale, and is provided with jaws that move laterally, like the wings of a folding door. The alimentary canal extends throughout the entire length of the body, 5 165 6 and on each side of it is placed a silk gland (fig. 2). These consist of two whitish or amber-colored cords, which after innumerable curves unite in the spinneret in the region of the mouth. There are also two glands, whose excretory canal opens in the spinneret, and covers the silk as it comes out with an impermeable varnish rendering it insoluble in acids and alkalies. This varnish is about a fifth of the weight of the thread. Hatchings usually occur annually in the spring. Simple contact with the air causes the new-born insect imme- diately to acquire a volume larger than it had in the egg, and it quickly begins to gnaw the under surface and edges of the mulberry leaf. It eats day and night at all hours, except when asleep, and in about thirty days grows 14,000 times larger than it was at birth. As the silkworm grows larger it becomes paler in color, because its dark chestnut brown hairs are scattered over a larger surface, thus showing more of the true color of the skin. About five days from its birth the vitality of the larva decreases, and it eats scantily or not at ail,and becomes thin and whitish in color. Then it moves around unquietly, and finding a convenient place attaches itself to it, holding on by its false feet. It thus remains motionless, with the front part of its body raised up, for a period of time varying according to tempera- ture,and takes its first so-called ‘‘sleep,” or molt, during which time the body undergoes extraor- - ene ees Mes; dinary modifications. The skin is entirely shed, - : p, portion o glands which secrete the andall the tissues that can not keep up with the Sa. canal: fain, Tapid growth of the insect are changed. neret; g, accessory glands | The scale which covers the snout is the first ae from Verson and Hart of the case to fall, and a new case appears under the former one. The worm then pushes itself forward through its first ring, sets at liberty the legs of the thorax, and by a wriggling movement comes out of its old sheath. To facilitate this difficult change a liquid is secreted between the old skin and the one forming beneath it. The life of the larva is usually divided into four ages, varying in length according to temperature, frequency of feeding, race, and the robustness of the worm. The following is about the average: First age, from birth to first molt, five to six days. Second age, from first to second molt, four days. Third age, from second to third molt, four to five days. Fourth age, from third to fourth molt, five to seven days. Fifth age, from fourth molt to maturity, seven to twelve days. 165 i Some time after each molt, perhaps the time needed to regain lost strength and to solidify the newly-formed organs, the worm remains in a state of relative torpor. Not much practice is needed to recognize when it has come out of its ‘‘sleep.” It moves its head and thorax, which are whitish, while the rest of the body is gray, and has com- pletely lost the shining aspect which it had when the worm began to molt. When fairly through its first molt the larva begins again to eat, and its hunger does not cease until it is ready for a new molt. Four molts having been made, the worm eats a prodigious quantity of leaf until it reaches its maximum growth, when its appetite diminishes and ceases altogether. It then stops moving and remains for some time in repose, evacuating, meanwhile, its digestive canal, thus losing up to 12 per cent of its weight. Its lean body is now white or yellow, according to the race, and semitransparent. Very soon it begins to move about again, lifts up its head, which is longer and more pointed, and turns in every direction seeking to find a convenient angle, finding which, it throws out a silk thread from:its spinneret. First a net is formed to hold the cocoon which is to be spun, then the regular spinning begins and the form of the cocoon is designed. For some time through the veil which very soon is to sur- round it, the diligent larva, with its back turned outward, may be seen completing its task. It is calculated that with its head alone the silk- worm makes 69 movements every minute, describing ares of circles, crossed in the form of the figure 8 (fig. 3, a). Meanwhile the web grows closer and the veil thickens, and in about seventy-two hours the worm is completely shut up in its cocoon, which serves it as a protective covering. THE CHRYSALIS. In the cocoon the silkworm goes through the last phase of its larval life. After four or five days the skin breaks, and the insect which So“, x Ys a Fic. 3.—The chrysalis: a, silkworm completing its cocoon; b, cocoon and chrysalis—cast-off skin of larva beneath; c, back view of chrysalis; d, side view of chrysalis. (Redrawn from Maillot.) issues from this old covering is the chrysalis, whose weight is often only half that of the larva at its highest development (fig. 3) 165 8 The chrysalis seems to have neither head nor feet, is golden-colored at first, and then turns chestnut brown. The skin dries rapidly and forms a hard case, on which the lines of only the posterior rings are seen, the place of the first three rings being covered with the wing-cases. The chrysalis state is in certain respects a sleep and in others a period of great activity, in which the entire being is transformed. Wings, antenne, reproductive organs, and legs are all now developed. This state lasts from eighteen to twenty days, according to the temperature. When the metamorphosis is complete, the sheath breaks in the region of the head and the moth or perfect insect issues. THE MOTH. The larva in spinning the cocoon leaves one end less dense, so that — the threads open freely to permit the egress of the moth. By the aid of an alkaline fluid the moth sof- tens and parts the threads and lib- erates itself. The moth (fig. 4) comes out of the cocoon, as the larva out of the egg, in the early morning hours. It has a distinct head, thorax, and abdomen, four wings, two comb-shaped antenne, three pairs of legs, and a pair of compound eyes. Shortly after emerging, the nioth deposits a liquid substance, generally white, sometimes color- less and sometimes reddish, and then the union occurs, lasting sev- eral hours, after which the eggs are laid either immediately or in the course of four or five hours. A gelatinous substance supplied by two glands near the extremity of the oviduct covers the eggs as they come out, and causes them to adhere to the substance on which they are laid. The laying, consisting of 300 to 700 eggs, is generally completed in three days, 70 to 80 per cent being deposited the first day, 20 to 30 per cent the second day, and a few the third day. The mother moth dies six to twelve days later, her death being usually preceded by that of the male. Death occurs more or less speedily, according to the robustness of the moth, the temperature, and the tranquillity in which it has been left. Thus in about sixty-five days the silkworm has completed its cycle of existence, its three periods being thirty to forty days in a larval 165 Fie. 4.—The moth: a, the male; 6, the female. 9 state, fifteen to twenty days as a chrysalis, and eight to twenty days as a moth or perfect insect. The rapid development of the silkworm and its marvelous transfor- mations indicate extraordinary power and very active functions. Its respiration is almost equal to that of the frog and of certain large birds, and it must be always surrounded by plenty of pure air. THE FOOD OF THE SILKWORM. The leaf of the white mulberry is the natural and the best food for the silkworm. There are many varieties of the white mulberry—some much better adapted than others to commercial silk culture, and some better suited to certain localities. CULTURE OF THE MULBERRY. As the securing of a food supply is a necessary condition to silk- worm culture, some information on the culture of the mulberry, con- densed from a bulletin of the Bureau of Plant Industry, “ is inserted: Of the mulberry there are many so-called species and a great many varieties, but there are only one or two species and a few varieties which are of importance in silkworm propagation. Chief among these for producing silkworm food is the white mulberry, Morus alba. This is thought by some to bea native of China. It is hardy over a large area of the United States. Most of the silkworms reared in China are said to be fed upon Morus multicaulis. This mulberry was largely planted in the United States many yearsago. Few, if any, of the original trees remain, but specimens which are thought to be wild seedlings of these are very plentiful in the Southern States. These trees are thoroughly accli- mated and free from disease. Itis therefore probable that there is now in the United States an abundant supply of material for propagating purposes, at least. The white mulberry, under good cultivation, is a low-growing tree, seldom attaining a greater height than 25 or 30 feet. It will reach this height in a comparatively few years after planting. In the vicinity of Washington the trees flower about the middle of May and ripen their fruit during June. The mulberry may be propagated by means of seeds, cuttings, layering, grafting, and budding. Seeds and cuttings are, however, the least expensive and trouble- some, and the most satisfactory means of propagation. Propagation by Means of Seeds.—This is the most convenient and rapid method of propagation. To remove the seeds from the berries, place them in a large bucket or a tub and squeeze them with the hands until they form a jelly-like mass. Add water and stir well to allow the seeds to sink to the bottom. The water and pulp can then be poured off, and the seeds can be dried by exposure to the air. The seeds may be planted at once, or they may be kept over winter and planted in thespring. Beds about 5 feet wide should be thoroughly prepared. The seed should be sown broadcast, not too thick, as crowding makes weak plants. Press the seeds in with the back of a spade and cover lightly with fine soil. For protection from the heat of the sun, over the beds should be placed lattice-work screens made of lath, and over these canvas should be spread until the plants show above the ground. After that the canvas is unnecessary except in the hottest part of the-day. With spring-sown seeds the lath screens without canvas will be sufficient. «Bul. No. 34, Bureau of Plant Industry, U. 8. Department of Agriculture. By George W. Oliver. 165 10 Seedlings vary considerably from the parent tree, and many of the seedlings grown will be found to have leaves of undesirable quality. Hence careful selection should be practiced and many of the seedlings must be rejected. The Use of Cuttings.—For propagation by means of cuttings in the summer time, selected seedlings which have made considerable growth may be used. Two or three leaves clipped to half their length should be retained on the cutting (fig. 5,a.) The cuttings should be set sloping in beds of moist sand in a cool propagating house, or, if such is not available, in a cold frame with northern exposure; if in the shade of trees, so much the better. The sash should be kept closed to conserve the moisture of the atmosphere until the cuttings have taken root. When considerable root growth has been made they should ~ be transferred to beds in the open, being placed 6 inches apart each way and well watered until estab- lished. The supply of winter cuttings should come from dormant wood taken from the trees just after the leaves have fallen. The cuttings (fig. 5, 6) should not be less than one-fourth inch in diameter and should be about 10 inches in length, the top cut being made about a half inch above a bud. The cuttings should be tied in bundles of 50, and these may be buried in moderately moist sand or ashes until spring, when they can be put out in rows in well- prepared soil. These nursery rows should be well cultivated and kept clear of weeds. Another method of propagation from cuttings, and a very success- ful one, consists in selecting me- dium-sized shoots about the begin- ning of November. These, before being made into cuttings, are sorted into bundles of different | lengths, tied, and heeled in ashes b b or sand, or in a mixture of both, and protected by a frame having a Fie. 5.—Mulberry cuttings: a, a summer cutting; b, b, win- northern exposure. During the ter cuttings. St Aya. ANG 6 \ 1) I { \ winter they are taken out and cut into lengths of about 5 inches. These are tied in bundles and buried in moist sand or moss. In early spring they are untied and put quite thickly in a propagating bed having a mild bottom heat, where they will root rapidly. When such a bed is lack- ing, wooden flats about 4 inches deep may be used, but they must have the protec- tion of a frame covered with sash. If a little loamy soil is placed in the bottom of the flats the cuttings will remain in good condition fora considerable time after root- ing and until a favorable opportunity arrives for planting them out in nursery rows. Planting. —The mulberry grows well in a great variety of well-drained soils.. The young trees should be transferred from the nursery to their permanent places either 165 LE in the fall or in the spring. If in the fall, the transplanting should be done when the leaves have matured or fallen. In the spring transplanting may take place as soon as the ground is in good workable condition. The ground should be deeply plowed and thoroughly harrowed. If the ground is hard and the soil poor, large holes should be dug and filled with good soil as the trees are planted. In trans- planting the roots should never be allowed to get dry. When taken up they may be immediately dipped in a mixture of soil and water and then kept covered until planted. The distance between the trees should not be less than 10 feet each way. If the grove is to be large, wider spaces should be left at intervals, so that wagons may be driven through. Pruning.—Pruning is best done in the fall or winter. The central part of the tree should be kept open to admit light and air. The low, spreading form of tree ismuch the best, and this form is secured by systematic pruning, which is begun by cutting the young tree back one-half in the fall after it is first planted out. Afterwards three or more strong shoots should be selected to form the main branches, and, if necessary, these may be prevented from growing upright by means of sticks fastened between them in such a way as to force them to spread apart. In gathering the leaves always allow enough to remain on the tree to insure its perfect health. If some of the trees show signs of failing vigor as a result of excessive leaf gathering, it is advisable to allow them to grow for a season without picking, and by early pruning out of unnecessary growth permit those growths which are desirable to become ripened. Restricting the height of the trunk of the mulberry to 5 or 6 feet makes it possible for old women and children to gather leaf, thus diminishing the cost of labor one-half, a most important point in commercial silk culture. It is also important to cultivate trees that bear little or no fruit, for the production of fruit not only consumes part of the strength of the tree, but much labor is involved in being compelled to divest the branches of fruit before they can be used as food for silkworms. The stump mulberry, or that growing low like a shrub, the hedge mulberry, and that which grows along walls vegetate much earlier than the medium and high trunk trees. Silkworm rearers should always have a ready supply of leaf for the first ages of the worm, and especially is this necessary if early cultures are desired with a view to escaping the heated days of May and June. AMOUNT OF LEAF AND PREPARATION. The race, the size of the worms, the variety and age of the mulberry, the nutritive quality of the leaf, the year, the season, and the climate make the requisite quantity of leaf very variable. The following is given as a basis of calculation, all circumstances being considered, and the leaves not being cleaned: For the larve hatching from 1 ounce of eggs, during the first age, 11 pounds of leaves; during the second age, 26 to 33 pounds; during the third age, 88 to 145 pounds; during the fourth age, 264 to 352 pounds; during the fifth age, 1,540 to 1,760 pounds; or about 2,200 pounds in all, of which one-half is consumed in the last six or seven days of the fifth age. 165 12 The age of the leaf should be relative to that of the worm. Young worms fed on old leaf, or old worms fed on young leaf, are apt to become diseased, and even though they may not die, will scarcely molt or will spin indifferently. A change of leaf, too, should, if pos- sible, be avoided, or made gradually. Fresh leaf only should be used, and never when wet with dew or heated, or before it has in a measure acquired the temperature of the room in which the worms are being reared. It should be gath- ered early in the morning or in the evening and should not be bruised or torn, nor should the baskets or aprons used to carry it be the same which are used to remove litter. To avoid fermenta- tion the leaves must be spread out in a cellar or cool, darkened room. Cut up only a limited quantity of leaf at a time and cover with a damp cloth to keep fresh, but never submerge the leaf in water, as this is apt to occasion flacherie, a very destructive disease. From the fourth age on there should always be a day’s supply ahead, so that in case of rain the worms will not have to fast. In gathering leaf, always strip the branches from base to top, so as not to tear the bark and injure the new buds. The sacks for holding the leaves should have a hoop around the opening and a hook to sus- pend them to the branches. Fig. 6.—Light moyable shelves. IMPLEMENTS NECESSARY TO SILKWORM CULTURE. Commercial silk culture requires a smaller outlay of capital than almost any other industry. The net gain the first year may pay for an outfit which will last for many years. The following articles are indispensable: (1) Some very light movable shelves, open to air, for the first ages; and, for the following ages, latticed shelves about 33 feet wide, and stands to support them. (2) Unsized ordinary wrapping paper or newspapers to cover the shelves. (3) A small ladder, if necessary, to reach high shelves. (4) Small trays to remove worms. 165 13 (5) Knives to cut leaves and baskets to distribute them. (6) Coarse tulle and nets or perforated paper for changing beds and equalizing the worms. (7) A supply of brush, straw, or shavings to construct the spinning place. (8) A thermometer. Wire, twine, laths, or canes are suitable for the lattice work of the shelves. Make the space between the shelves about 14 inches. If i (\) onicouumumc \\ A OMA TUM | mi Fie. 7.—The rearing room (after Gobin). possible, do not arrange the shelves along the wall, and allow a good passage between the tiers of shelves (figs. 6 and 7). SILKWORM EGGS: HOW TO WINTER AND HATCH THEM. There are two kinds of silkworm culture: One for production and one for reproduction. The object in the first case is to get the greatest yield of cocoons, and with a little training, may be carried on by anyone of ordinary intelligence. The object in culture for reproduction is to secure eggs free from hereditary taint of disease, and experts only can be depended on to conduct it. Besides a careful physiological examination through- out the rearing, the body of the mother moth is microscopically tested after death, and her eggs are not retained if signs of disease are discovered. In this way the birth of healthy worms is insured. Pasteur first applied this method of selecting silkworm eggs, and thus checked the plague (pebrine) which was rapidly destroying silkworm culture in Europe. 165 14 Formerly, through an indiscriminate use of eggs, disease invaded the rearings to such a degree that from 65 to 90 pounds of cocoons was considered a good yield per ounce of eggs. At the present low price of silk such cultures are no longer remunerative, and industrial silk culture now demands the exclusive use of scientifically tested eggs. The grainage, or preparation of eggs for market, constitutes a special department of silk culture. In Italy there are over 400 establish- ments which supply eggs to raise the annual silk crop. The poorest peasant, though well skilled in the art of rearing silkworms, would not risk a rearing with eggs which have not been selected and pre- served by experts. The eggs of crossed races are best for culture with a view to pro- duction of silk, and here, as much as in the examinations which have been referred to, the knowlege of experts is needed. The life of the egg, in those races which have but one generation each year, has three phases, the first lasting about three months, full of activity; the second lasting from about October to the middle of Febru- ary, one of inactivity, in which there are no signs of life; the third from the middle of February to the moment of hatching, in which the vital activity recommences, and the germ begins to organize as soon as the temperature rises a little above 50° F. The measure of the activity of the egg, in this stage, is the measure of its danger, for any sudden change of temperature would injure or destroy the delicate embryo, or cause the larva to be born before its food was ready. To guard against such accidents, eggs must be wintered in a high region or ina refrigerator at a uniform temperature of about 35° F., from December 15, until the mulberry begins to bud or until hatchings are desired. There should always be good ventilation, the air should not be moist, and great care must be taken to keep the eggs out of the reach of mice and insects. Natural hatchings are almost always irregular, extending over eight or ten days, thus multiplying the divisions and rendering the rearing difficult and costly; hence, the necessity for artificial incubation. Kighteen days before the time decided on for the hatching, spread out the eggs in thin layers in the incubating room or incubator. The temperature should be 55° F. From the fourth day on, gradually increase the temperature two degrees in twenty-four hours until 73° F. is reached, when, at this uniform temperature, hatchings will occur in ten days on an average. This period, however, varies from eight to fifteen days, according to race, the cold supported during the winter, the first grade of heat, and the highest during the incubation, and the number of days taken to pass through these two grades of heat; and also according to the humidity. To obtain a good and complete hatching, a slight humidity 165 15 is necessary, especially during the last four or five days. To secure this keep an open vessel of water near the fire, or sprinkle the floor with water occasionally. The temperature may be raised during the hatching to 75° F., but sudden changes of heat must be avoided, and, unless the newborn worms can be kept in the same temperature, it is dangerous to have the maximum temperature of the incubator so high. It is better for the period of incubation to be protracted than sud- denly shortened. Holding the eggs at a certain temperature, or slowly lowering the temperature a little does no harm. When the season is not propitious, the hatching may in this way be retarded. An incubating room is preferable, because it also serves for the first two stages of the worms, but in small rearings an incubator is more economical, both with regard to service and to fuel. For a large quantity of eggs (5 to 10 ounces) a small incubator, which is very much used in chemical laboratories to dry substances, is recommended. Any ordi- nary tinsmith can make it. It consists of a double case, cubical in form, with a zinc bottom. The space between the outer and inner walls is filled with water. The front face of the cube is furnished with a glass, so that the temperature within, indicated by the thermometer hanging on the glass, may be seen with- out the necessity of opening the incu- bator. There are two openings below on opposite sides to allow the cold air to come in, and an opening in the center of the top to permit the outward flow of the heated air. Having filled the space between the walls with water through the pipe, the incubator is placed on a support and heated by means of a gas or oil lamp to the desired degree, and, by raising or lowering the flame, a constant or progressive temperature can be maintained (fig. 8). A self-regulating incubator, such as is used to hatch chickens, would be more convenient, but would cost more. The whitening of the eggs denotes the near approach of the hatch- ing. Double pieces of tulle or sheets of perforated paper sprinkled over with finely cut-up white mulberry leaves should then be lightly placed over the eggs to allow the outward passage of the worms as soon as hatched. The object in employing two pieces of tulle or paper is to prevent the unhatched eggs which cling to the sheet from being removed with the newborn worms. This process must be 165 Fie. 8.—Hot waterincubator. (Redrawn from Verson and Quajat.) 16 repeated daily during the hatching, the second sheet always being renewed. The duration of the hatching varies from three to five days, the eggs hatching about as follows: During the first day, 5 per cent; during the second, 33 per cent; during the third, 50 per cent; during the fourth, 5 per cent; during the fifth, 7 per cent. Twenty-five grams of eggs will give about 17 grams of worms. In small rearings most cultivators raise only the worms that are hatched on the second and third days, to avoid the necessity of forming too many classes. The worms must be classed according to the date of birth, and the insignficant number hatched on the first and last days scarcely compensate for the trouble of rearing them. Different races must also be reared separately. Where several in one neighborhood are engaged in silk culture it greatly reduces the cost to have all the eggs hatched in one incubator. The person best acquainted with silk culture can undertake the incu- bation, and distribute the young worms on the second or third days to those who are to rear them. This is the plan adopted among the Italian peasantry, the wife of the supervising farmer hatching the eggs for whole villages. THE REARING OF SILKWORMS. Before entering into the details of a rearing some general directions must be given concerning the rearing room—the heating, ventilation, and disinfection. GENERAL DIRECTIONS. The place chosen for a rearing should be relatively high, and not exposed to malaria or bad odors, and mulberry trees should grow around it. Any room that can be properly heated and ventilated will answer the purpose. An open fireplace is the best means of heating, but is expensive, as much of the heat is lost. Hot-water pipes, such as are used to heat a greenhouse, are good for a building specially built for silkworm rearing. Iron stoves should not be used, unless placed in an adjoining room with communicating pipes. Never employ charcoal as fuel. Ventilation—The domesticated worm should be surrounded contin- ually by pure air. The amount of carbonic-acid gas given out by the worms and their attendants is very considerable; besides this, a quantity of deleterious gas is generated by the litter of the beds, and the lights and fires consume a great deal of oxygen. Myriads of spores and germs of organic life float in the air of the rearing room, and their influence paralyzes the vital energy of the skin and of the organs of respiration, on whose normal functions the robustness of the worm so much depends. Hence, it is evident that the quantity of 165 i vitiated air which should be expelled from the room requires the introduction of a large quantity of fresh air. For this, a double system of ventilation is necessary, which may be obtained by double openings in the windows, to allow the heated bad air to pass out above and the cool fresh air to come in below. To renew the air in every part of the room, and to avoid.a single and often violent cur- rent, there should be more than one window. An open fireplace is the best means of ventilation. When the difference between the external and internal air is slight, or there is no difference at all, arti- ficial means must be used to create a current. Light and frequent fires, or a burning lamp in the fireplace, or a revolving fan, may be used to prevent stagnation of the air. Disinfection —FHight or ten days before introducing the worms into their quarters all the shelves and implements should be washed in a solution of chloride of lime (11 pounds of chloride of lime to 88 quarts of water), or in a solution of sulphate of copper (1 to 100 by weight). When everything is in order—tools, perforated paper, material for the worms to spin their cocoons on, etc., each in its own room—close the doors and windows as tightly as possible and fumigate the rooms with sulphur (11 pounds of sulphur to every 100 cubic yards of space). To fumigate properly, powder the sulphur and place it in an earthen or metallic vessel over a slow fire. The sulphur will gradually melt and take fire. Place it immediately in the rearing room and leave it, with the doors and windows completely shut, for twenty-four hours. Nets should not be exposed to sulphur fumes, for this would soon rot them, but should be washed in a solution of sulphate of copper, and immediately afterwards in plain water. Twenty-four hours after the fumigation the floors should be washed with a solution of chloride of lime or sulphate of copper, and the walls should be whitewashed with lime. When dead worms are seen on the shelves, change the beds and create in the rearing room sulphurous gas by burning a pound of sulphur during six hours, or make a strong wood smoke, which is a good disin- fectant and will not harm the worms. Precaution haying been taken to destroy germs of disease in the rearing room, the new-born worms may now be safely installed there. Space Required.—The worms from 1 ounce of eggs should cover at birth 1 square yard. Doubling this space on the fourth day, they would require 2 square yards, and at their change of beds after molt- ing, 4 square yards. By the spacing of the third day of the second age, and the doubling of beds preceding the second molt, they will need for the second age 8 square yards. For the third age 16 square yards will be required; for the fourth age 32 square yards; and for the fifth age 60 square yards. The more space that is accorded to the 20838 —03—-2 165 18 worms in their first ages, the more robust they will be; and if the space can be tripled instead of doubled during the fourth age, and for the fifth age be 70, 80 or 90 instead of 60 square yards, the harvest of cocoons can be raised from 60 kilograms to 70, 80, or 90 kilograms per ounce of eggs, the quality of silk also being superior. Temperature.—The silkworm is not a tropical insect, and attains its best development between the temperatures of 68° and 77°F. It is safe to adopt the mean between these two temperatures for the general rearing. Each cultivator, however, may suit his convenience, remem- bering that to fall below or to exceed the mentioned limits of heat is detrimental to the worm, and will affect the quantity and the quality of its spinning. From the second age the temperature should be from 70° to 72° F. and should be kept as uniform as possible to the end of the rearing. — The time which elapses between one change and the following one may be much shortened by raising the temperature and feeding oftener. Such hasty rearings may be made in twenty-two to twenty-four days. They are, however, to be condemned, as contrary to the nature of the silkworm. Meals following each other too closely can not be properly digested, and are likely to cause disease. Besides, hasty rearings require more labor, and the service must be kept up night and day. As there is danger in too high a temperature, so there is danger in one that is too low (64° to 68°F.). A rearing that is too prolonged, lasting over thirty-two days, is to be avoided to escape the heat of June, under which the beds are more likely to ferment, causing disease; the worms have less appetite and leave more leaf from one meal to another; the changes are slower and less likely to occur instantane- ously; and there is more risk of muscardine or calcino, a disease due to a mold. - Both hasty and tardy rearings are, therefore, to be proscribed, and those conducted in twenty-eight to thirty-two days alone are recom- mended. This lapse of time permits the leaves of the mulberry to acquire maturity, and the growth of the worm should be relative to that of the leaf on which it feeds. THE FIRST AGE. Hatchings usually occur early in the morning. The worms which have crawled up through the holes of the tulle or paper to get food, should not be removed before 10 a. m. to the latticed shelves covered with paper to receive them. Each shelf must be marked with the date of the birth of the worms put upon it, and care must be taken to place on the same shelf only worms born on the same day, as a remu- nerative rearing demands that such alone be raised together. Should the hatching occur at 68° to 70° F., keep this temperature during the first ages, and feed eight times during twenty-four hours; if 165 19 the temperature at birth is 75° to 77°., slowly diminish the tempera- ture one or two degrees, and feed ten times in twenty-four hours. The appetite of the worm increases or diminishes with the heat. The second day, in case of the worms hatched at the maximum, adjust the temperature to the degree proposed to conduct the rearing. In feeding sprinkle finely cut up tender leaves frequently over the worms, and toward the fourth day begin to regulate the number of meals so that it will range from four to eight, according to the temperature. Before cutting the leaf remove the stems. Distribute the leaf uniformly and equally on the shelves, in order to prevent the worms from crowding more on one side than another, and in order that they may be equally nourished and make their changes simultaneously. Cut only a small quantity of fresh leaf ata time, and keep the rest in jars or baskets covered with a damp cloth. Never submerge the leavesin water. For the first two or three ages, the white ungrafted mulberry is recom- mended, it being lighter and more digestible for delicate worms. It is well during the feeding to open the door and windows to insure a good supply of freshair. After feeding, close the door and windows, unless the day is warm, when they may be permanently left open, pro- tected by curtains through which the air passes freely. The worms should never be exposed to direct sunlight or to a strong current of air, and during a thunderstorm the windows and doors should be closed. Worms of the same age and development should be classed together. To obtain this equalization, do not feed newborn worms until all that have been hatched on one day have been removed to shelves, then give a general meal. If at the end of two or three days it is noticed that on certain shelves there are smaller worms than on others, in order to allow the less developed worms to catch up with the more advanced ones, place the former nearer the fire or on the highest shelves, where the air is warmer, and give them one or two more feeds than the larger worms. For this reason it is well to have light movable shelves. Many cultivators of silkworms do not change the beds during the first age, and it is not absolutely necessary, if the leaf has been well cleaned of stems and very finely cut up, and, above all, if the airisdry. Change of bed, however, must be made if the litter is damp, and the weather rainy, for the worms are going to molt in two or three days, and this crisis should not occur in unhealthy conditions. It is always more prudent to change beds on the fourth day, and is, therefore, advised. The space occupied by the worms must be doubled when the change of beds is made. The bed on which the leaf and excrement accumulate is, perhaps, the greatest source of danger to the worms. When there is not a free circulation of air, gases are developed which almost always cause fer- mentation, paving the way for future disease. Hence the necessity for frequent change of beds. This is made in various ways. The 155 20 practice of doing this by hand is to be condemned because it consumes too much time and is apt to injure the worms. Thread nets (fig. 9) and perforated paper are the best means to employ. They save two- thirds of the hand labor, and thus allow beds to be oftener renewed, which is a most important consideration. In the first age tulle or mosquito net may be employed instead of nets or paper. The manner of proceeding is as follows: Place the last meal at night on the nets and extend them over the worms. By morning the worms will have mounted above the opening in search of fresh leaf. Then lift up the nets, beginning at the top shelf, and place them on clean shelves. Carefully detach from the nets any portion of the old bed, and, if the worms are not molting, gather up the few worms that have remained behind, and tenderly place them with the others. The change of beds is thus rapidly effected with the least labor. It is very important that the tension of the net be such as to prevent the worms from being crowded together in the middle. Perforated paper (fig. 10) is another means often used to effect change of beds; but it does not allow the worms to mount with the same facility. It is also apt to break when the worms hecome heavy, and in many cases it has to be renewed annually, so, in the end it is no cheaper than nets. In changing beds, do not feed the worms that are first taken up until all from the old bed have been removed; then give a general meal, for all the worms born on the same day and forming one class should have the same num- ber of meals to preserve their equality of growth, which is necessary for a successful rearing. Having adopted hours for feeding, these should be adhered to throughout the rearing. When four meals are given, the best hours are 5 to 6a. m., 10 to noon, 3 to 6 p. m., and 9 to 11 p. m. Toward the,sixth day worms begin to eat less. This is a sign that they are going to molt. Thenanother change of beds and doubling of space are necessary. The molt or change of the worm is easily recognized by a swelling of the head, whitening of the skin, transparency of the body, anda fixed position, 165 Fig. 9.—Net used in changing beds. 21 To change the beds, proceed as before, only leave undisturbed on the old beds the worms that are molting. When all the tardy worms have been taken up and placed on shelves, give them frequent sprinklings of finely cut up leaf to enable them to catch up with the worms already molting. Diminish the feeding as the backward worms begin to molt, and cease feeding entirely as soon as a single worm comes out of the molt. Then wait twenty-four hours so that the worms may be well over the change before giving a general feed. In this way the equality of development necessary for a methodical and successful rearing is maintained. A fast of twenty-four hours will not hurt the advanced worms, while the extra feeding given to the backward ones may enable them to become equal to the former. \\ NN iS N —Al\ . \ & ‘\ XY iN erry ) 2) \ f \ \\ & WN ‘\ Fic, 10,—Perforated paper used in changing beds in the second and third ages. The beds or the worms on the old litter may be changed when the general meal is given. Many cultivators do not change the beds and double the space until after the first molt, allowing all the worms to change in the same bed. In this case, owing to the distribution of leaf for one or two days after the molting has begun, the molting worms are covered by a more or less thick coat of litter, and exposed to emanations of bad gases in a critical period of life, which is likely to cause disease. Besides, in the first age, the worms are so small that they are likely to be lost in the litter, or to perish from suffocation. Hence, it is healthier to change beds and double the space before the molt. 165 22 THE SECOND AGE. The coming out of the molt is announced by the appearance of a small triangular-shaped livid spot on the worm’s head, and the changed skin is grayish in color. The worm takes several hours to recover from a change; then it begins to search for food, which, however, as before stated, must not be given before all the worms have recovered _ from the molt. Then a slight meal is given by means of perforated paper or nets. The worms crawl up promptly and can be easily gathered up and placed on fresh shelves. If the two sets of worms recover from their molt at the same time, they may be classed together; if there is a difference of a day, it will be necessary to keep them separate throughout the rest of the rear- ing, for the equality of age has disappeared, and, if they are put together, the second change will not occur simultaneously for all the worms, but will extend over several days, and occasion the greatest trouble to reestablish the equality of size necessary for the best results. In case no worms have had change of bed before the molt, do not recommence feeding until the greater part of the worms are awake. Do not fear that they will suffer from hunger. Then form a new division of those still molting. It is frequently better to have two divisions, but if, to simplify the work, but one is desired, by putting the backward worms on the highest shelves, and feeding them oftener than the advanced set, an equality may be reestablished. Three days after the first molt the beds must be renewed, and at the same time more space must be allowed the worms. The second age is the shortest, being less by two or three days than any of the others. Toward the fifth day of this age the worms begin to molt again. Then act as before—that is, by aid of nets or per- forated paper, remove the backward worms, in order to place them elsewhere, and try by more heat and abundant food to make them catch up with the forward worms. THE THIRD AGE. When the worms are over their second molt they cease to be gray, and take the characteristic color of their race. If they are too long in molting it is because the temperature is too low; that is, below 68° F. Increasing the heat a few degrees will excite the worms and enable them to complete their change. After this the temperature adopted for the rearing must gradually be resumed. The worms double their size in their third age; consequently the space allotted to them must be doubled; that is, they must have 16 square yards instead of 8 square yards, as in the second age. From the second to the third molt the same care is to be given as has been prescribed for the first two ages, except that, if a small incu- bating room has been used instead of an incubator, the worms must 165 23 now be transferred to a larger room to complete the rearing. Care must be taken to heat this room the day before to 80° F., and the next day lower the heat to the degree adopted for the rearing. Feed six times daily either with whole leaves or leaves which are coarsely cut up. For this as well as all the other ages the best rule to follow in feeding is to give only a light sprinkling of leaf at the beginning and end of each age, gradually increasing the ration up to the middle of each age, and then diminishing to the time of a molt. The appetite of the worm will serve asa guide. Give more or less leaf according as the preceding meal has been more or less eaten. In this way leaf will not be wasted and a large quantity of litter will not accumulate under the worms, to their detriment. Toward the sixth or seventh day of the third age, according to the temperature, the worms begin to be languid and lose appetite, as before, and are ready to make a third change. This is the most diffi- cult of all and the one in which they seem to suffer the most. It is also the period when diseases due to bad eggs or to a poor incubation are developed. Excepting accidental diseases, a good result may gen- erally be predicted if the third change is safely passed. With these facts in view, from the beginning of the third age keep the worms sparse on the shelves and see that the beds are dry and changed with scrupulous care, the litter being far removed from the rearing room. Avoid feeding with wet leaf, and to favor the molting raise the tem- perature a degree. It will be noticed that the head and body of the worm are more swollen than in other molts. It is this superabundance of liquid that renders this molt so critical and necessitates a drier atmosphere and a bed which is very dry and not apt to ferment. The worms increase three times in volume after the third molt, and must have space accordingly. They must be separated into three divisions in the following manner: Instead of waiting, as in the first two changes, until half of the worms have begun to molt, let down the nets, or otherwise prepare for the removal of the backward worms when one-third or even less of the worms show signs of molting. About two-thirds will then crawl up on the fresh leaves, and must be placed on a shelf where, after one or two meals, they proceed to molt, being again divided after the first or second distribution of leaves, according to the rapidity of the molting. If only a few worms mount when the first division is made, the oper- ation was delayed too long, and it is unnecessary to divide those first taken up; butafter the change the division of those left on the old bed can be made. To allow the worms to spread out, each division should occupy but one-third of the shelf on which it is placed. THE FOURTH AGE. When all the worms have molted the third time a change of beds must be made as in preceding ages. Do not be in haste to change. 165 24 Wait a few hours to permit the worms to recover their strength a little. The recommendation to feed lightly at first applies especially to the beginning of the fourth age. If the outside temperature is normal, fires need not be kept up, and the doors and windows may be left open, guarded by light curtains. In this age the worms eat enormously and more help will be required to gather and distribute leaf. Small branches of leaf may now be given in place of whole leaves, and the number of meals may be reduced to four, if the temperature is 68° to 70° F., at which temperature the age will last nine days. If it is desired to reduce this age to seven or eight days, raise the heat to 72° F., and give five or six meals daily. Should change of weather retard the growth of the mulberry trees, and temporarily cut off the supply of leaf, adapt the rearing to such a con- tingency by lowering the temperature slowly to 66° or 68° F., and giv- ing only three or even two meals daily. Then, when leaf is obtained, gradually raise the temperature to the degree adopted for the rearing. During the fourth age four changes of beds are made, including the one which follows the third molt. A single division of the worms is sufficient, which will be the last, and particular care must be taken to divide the worms into two equal parts. For this, spread the nets or perforated paper over the worms when half are molting and proceed as before. . THE FIFTH AGE. Do not be in haste to change beds as soon as the worms have molted. This precaution is necessary to allow the new organs to acquire con- sistency, and to prevent worms from being lost in the litter. Conse- quently, wait several hours, and change beds after the second meal, the first being only a slight sprinkling of leaves. Worms are not strong enough immediately after a change to digest a heavy meal. The space during this age should not be limited. See that between two worms another could be easily placed. Experience has proved that the harvest of cocoons is often in proportion to the space accorded to the worms during this age. Feed from four to six times daily, according to the temperature, and spread the branches or leaves out regularly, not to form a mass. For a simultaneous mounting into the brush all the worms should eat an equal quantity of food. As ripe berries are very indigestible, and also cause beds to ferment, care must be taken to shake the trees well before gathering the leaves, and whatever ripe fruit remains must be taken off before feeding. If possible, change beds daily, especially if more than five meals are given, or if the weather is very warm and damp and there are signs of disease. The first five days after the change the worms grow enormously, and it is very difficult to satisfy their appetite. At the end of this 165 25 time the body suddenly diminishes in circumference, the excrement, formerly dry and firm, now becomes moist and soft, and the appetite diminishes and becomes capricious. This state generally lasts three days, then suddenly the worm ceases to eat, and tries to get away from its food. It prolongs its head, and, changing its former lazy habit of scarcely moving except to get food, runs about in every direction, stopping from time to time, and moving its head (now transparent gold or white, according to race) like a blind person seeking the way. These signs indicate that the worm is hunting a convenient place to spin its cocoon. The worm is now mature, and a spinning place should be ready to facilitate its metamorphosis. The humidity, which always exists at this time on account of the mass of litter, is especially dangerous to the worms; and it is increased if the worms do not all mature and mount at the same time, for those that remain below are wet by the liquid dejections of those that are the first to mount. For this reason do not put worms in the spinning place until they are perfectly mature. They then mount, and crawl around some time seeking a favorable place for their cocoons. Finding this they evacu- ate their digestive canal, and begin to throw around them an irregular net in which the cocoon spun later will be suspended. PREPARATIONS FOR SPINNING. A considerable loss may occur in the spinning place even when the rearing has been most successful. To avoid such loss observe the fol- lowing precautions: (1) Prepare the spinning place in time; (2) arrange it so that the worms may regularly mount, and have abundant room; (3) have it well made, yet economical; and (4) regulate the heat and ventilate the room. Any convenient dry bushy brush, odorless and free from gum, will serve to construct the spinning place; or if such is not available, bun- dles of straw, or shavings, or finely split up wood may be substituted. The best and most economical arrangement is small bundles of brush or straw placed upright between the feeding shelves, in rows, about 16 inches apart. The bundles are cut a half inch taller than the space between the shelves, and their tops are spread out to form arches, and to allow the worms plenty of room to spin (fig. 11). Branches of elm, oak, birch, etc., are used to place the worms in the spinning place. These branches are spread over the shelves at the end of the fifth age. Very soon they will be covered with mature worms which have ceased to eat, and are turning away from the mulberry. In this way it is easy to select the worms that should be transferred. If the worms are equally developed, in thirty or forty hours they will be shut up in their cocoons. The few that remain behind should be placed elsewhere; fed with fresh leaf on clean beds they will soon catch up with the others. 165 26 The fifth day after the mounting the worms that have not begun to spin should be placed in bundles of twigs and covered with straw or leaves, or put in a basket of shavings, where they will be forced to spin. The temperature during the spinning should be 75° F., and the humidity throughout the rearing about 65°. A good practical test of Fig. 11.—Arrangement of spinning places. (Redrawn from Pasteur.) humidity is a saucer of salt; when the salt is moist, reduce the humid- ity. Carefully avoid disturbing the worms while spinning, and then, as during all the ages, keep the room as quiet as possible. The most scrupulous cleanliness should always be observed, both with regard to the quarters and the attendants; to keep from raising dust, wipe the floor with a damp cloth instead of sweeping it. PREPARING COCOONS FOR THE MARKET. The transformation of the larva into the chrysalis is, according to the temperature, completed in from seven to ten daysfrom the time at which the first worm begins to spin. The cocoons are then said to be mature, and this is the best time to gather them. If gathered earlier, the producer will run the risk of having his cocoons rejected in the market; and if later, he will sustain a very sensible loss in their weight, as they grow lighter from the time of their maturity until the moth comes out. The best authority estimates the minimum loss as 4.1 per cent, and the maximum as 23.3 per cent. To avoid the risk of soiling them, gather the cocoons from the lowest shelf up. They may be freed from the web or floss by a very simple instrument (fig. 12) or by hand. After the removal of the web the cocoons are sorted into three classes: (1) The perfect, (2) the double, and (3) the defective or 165 27 spoiled. They are then spread out in 4-inch layers, on clean shelves, in an airy, dry room, not exposed to sunlight, and very carefully guarded from rats, mice, and insects. The defective and discolored. ones are put in a separate room. The thread of a cocoon is continuous with that of the web, and diminishes in diameter within. Its length varies from 1,200 yards to 1,600 yards, and its value accordingly. Different races, sexes, and conditions of rearing often produce notable dif- ferences in weight of cocoons. Thus the weight may vary from 155 to 320 cocoons to the pound (340 to 700 to the kilogram). Often two or more worms are in- closed in the same cocoon. Cocoons formed from such collaboration are F'%- 12-—Device for removing floss from P F cocoons. (Redrawn from Nenci.) larger than single ones, irregular in form, and cottony in texture. They can not be unreeled, and conse- quently are far less valuable than single ones. The proportion of silk in a cocoon varies according to the race and the régime to which the worm has been subjected. The average normal cocoon at the time it is sold is thus composed: : Per cent. \ i Sureip is vice ta aa) As OS EAE Bde eo BAS Stan ee een MES aoe BOL R Soe wrens eae Seams eels 68. 2 SHIR S525 SSE So Sg Ge ai en ae ree arene een me ea Sere ee eet ae 14.3 VV le: PON NET be Se ees ea Se ees See eee RN ae ee aee Bree =) Ae nil ONS TLLS 4 a ES ee a Sars Sen, See eee Ps bm pee Lo rte 16.8 If the cocoons are not sold as soon as gathered, the chrysalides should be killed without delay unless they are to be reserved for reproduction. Otherwise the moths may pierce the cocoons, thus rendering them unfit to be reeled. The chrysalides are usually killed either by heat or suffocation. The means most commonly employed are (1) the heat of the sun; (2) hot dry air in a stove; (3) hot humid air in a stove; (4) steam; (5) oil of turpentine; (6) carbon bisulphid or some other gas. Probably the best of these means are steam at a temperature not above 212° F. applied without pressure, or hot damp air at a temperature of 196° F. The killing of the chrysalides is an important operation and one requiring care and judgment. If some are left alive, the moths will issue, thus rendering the cocoons of little value. On the other hand, if the operation is continued too long, the silk may be injured. The best methods are those in which the heat is carefully controlled and excessive dryness is avoided. The following is a very simple and easy way to destroy the chrysa- lides by the use of steam: Place a cauldron of water on a stove. When boiling begins set over the cauldron a white hollow wooden cylinder, about 3 feet high and 2 feet in diameter, with 165 28 a perforated bottom and open at the top. Arrange in this cylinder round baskets three-fourths filled with cocoons; then cover the cylinder with a perforated lid. In about thirty minutes the operation will be completed, after which remove the cylinder, take out the baskets, and spread out the cocoons to dry before storing, to prevent them from spoiling. Mr. T. A. Keleher of this office has adopted the following plan: The cocoons are placed in an air-tight box of about 24 cubic feet capacity; about half an ounce of bisulphid of carbon in a small dish is placed in the box and left over night. It is best to open one or two of the cocoons to find if the chrysalides are dead; if not the operation must be repeated. Care should be exercised that no fire of any kind be brought into the vicinity during this operation as the bisulphid of carbon is very inflammable. In shipping cocoons care must be taken to pack them in baskets or cases permeable to air, but sufficiently close to keep out rats and mice, which are very destructive to cocoons. DISEASES OF SILK WORMS. In every successful rearing of an ounce of eggs about 40,000 worms are hatched, and 30,000 succeed in spinning cocoons. ‘The rest either die from casual wounds or from diseases incidental to restricted action. But sometimes whole chambers are destroyed by hereditary and con- tagious diseases, and it is of supreme importance to cultivators to learn how these scourges may be avoided. In this limited treatise only a bare mention can be made of the most fatal diseases and of the necessary precautions to be taken to guard against them. The general cause of disease is the domestication of the worm. By using good eggs, however, and following the methods which are actually employed by successful rearers, remunerative results ~ are usually obtained. To obtain good eggs it is necessary to adopt new methods. These are chiefly such as involve the use of the microscope. Among the many diseases of silkworms, the principal ones are: Pebrine, flacherie or flaccidity, gattine or macilenza, calcino or mus- cardine, and grasserie. PEBRINE. This disease was first noticed in epidemic form in France in 1845. Since then it has appeared in Italy, Spain, Portugal, Turkey, Turkes- tan, the Caucasus, Kashmir, China, and Japan, threatening to destroy the silk industry. Between 1833 and 1865 the annual crop of cocoons in France was reduced by pebrine from 57,200,000 pounds to 8,800,000 pounds. No remedy has been found for the disease, but the Pasteur microscopical selection of eggs, insuring the birth of healthy worms, is a sure prevent- ive. The universal adoption of this method has made pebrine almost a thing of the past; and following Pasteur’s line of research, means have now been discovered for avoiding every kind of silkworm disease. 165 29 Worms affected with pebrine develop slowly, irregularly, and very unequally. Black spots are the most marked outward characteristics of the disease; the internal signs are oval corpuscles only visible through the microscope. Worms healthy born may contract pebrine during life, but this may not prevent their spinning, as the disease does not reach its climax before the chrysalid or moth stage, and in its incipiency the worm is strong enough to spin, though the moth will produce diseased eggs. Hence the necessity of repeating the microscopical examination for each generation of worms. Pebrine is not always visible, and when latent induces other diseases. When only one crop of cocoons is made annually, it is comparatively easy to resist pebrine, as the germ of it, outside of an egg, retains its vitality not longer than seven months. The disease takes thirty days to de- velop; therefore, if worms from pebrinized eggs can be made to spin within twenty-five days after hatching, they may yield a fair harvest of cocoons. In any case, however, it is only safe to use pure eggs, as pebrine, even in undeveloped stages, renders the worm more liable to contract all other diseases. FLACHERIE, OR FLACCIDITY. This is now the most dreaded disease among. European silk- worms. In general, worms are struck with it after their fourth sicbeh, ase Fic. 18.—Worms affected with flacherie dying in the molt, when they are mature, or brush (after Pasteur). even while spinning (fig. 13). Without any apparent cause, they begin to languish, then remain completely still, and shortly die. They blacken after death (fig. 14), and give out a disagreeable odor. Often entire chambers perish in a day. Again, the progress of the disease may be slow, the worms even spinning their cocoons, but, dying in the chrysalid state, they putrefy and soil the cocoon, thus greatly diminishing the value of the harvest. Flacherie is but another name for indigestion. Pasteur and many 165 30 other scientists assert that flacherie is due to ferments and vibrioni developing in the intestinal canal of the worm; other authorities main- tain that the disease may exist independently of these. However, as these micro-organisms, in the majority of cases, play a prominent part in the development of flacherie, it is well to guard against them. The principal causes of flacherie are: (1) Eggs being spoiled through careless preservation; (2) hereditary tendency; (3) overfeeding of worms; (4) wet, sweating, dewy, and fermented leaf; (5) leaf sub- merged in water or full of mud; leaf from a new plantation or from a shaded spot, coarse leaf, or change of leaf; (7) lack of ventilation; (8) excessive heat; (9) dust; (10) keeping worms too thick on trays; (11) accidental deaths of worms from injuries, these putrefying, and the ferments thus created being communicated to other worms; (12) debility. A If these causes are avoid- Fic. 14.—Worm which died of flacherie, putrefying after ed, flacherie is not likely to death, (Redrawn from Pasteur.) : : invade a rearing. To pre- vent contagion eggs should be dipped in a solution of sulphate of copper before being incubated; and in cleaning shelves and nets, wher- ever a dead worm is seen, powdered sulphate of lime or copper should be applied. Unlike the corpuscles of pebrine, the microscopic organisms, which are probably the immediate cause of flacherie, remain alive from one year to another, and the dust of a rearing room may contain them in considerable quantities and become the means of infection. Hence, in cases of flacherie, immediately after the rearing, the walls, shelves, and all the implements should be washed in a solution of chloride of lime or some other germicide, and the room should be fumigated with sulphur. GATTINE. The external signs of gattine are indifference to food, torpor, dysen- tery, and emaciation. It attacks the worm in the first ages, and is especially manifested after a molt. Sometimes it is associated with flacherie, and, in its incipient stage, is confounded with this disease. Later the worm becomes extraordinarily emaciated and sufficiently transparent to be mistaken for a mature larva. The hooks of the prolegs are lengthened out and strongly attach the worm to whatever it touches. Meanwhile torpor creeps on and soon ends its life (fig. 15). Worms having flacherie or gattine do not always die before mount- ing into the brush, and if the disease has not entirely invaded the organism they may even arrive at spinning. But instead of mounting with the promptness and rapidity of healthy worms, they stop hesi- tatingly at the base of the brush, then begin slowly to mount, stopping 165 31 on the first little twigs and distending themselves as though asleep, sometimes with the head turned towards the base. Again, especially in case of gattine, the worm wanders restlessly here and there, seek- ing as it were power to eject the silky matter, but too impotent to do more than throw out a scanty thread to weave a web or veil of a cocoon, in which it generally falls and dies. Eggs free from disease and capable of resistance to disease are the prime requisite — Fre. 15.—Worm emaciated by gattine in guarding against flacherie and gattine. _ fer the fourth molt. (Redrawn = from Nenci.) The moment some deaths are noticed, pro- ceed as follows: (1) Change beds immediately, briskly shaking the worms; (2) place the worms on disinfected shelves; (3) burn the dis- eased and suspected worms that do not mount on fresh beds; (4) if possible move the whole rearing to another room previously aired and disinfected, and also aired after disinfection; (5) do not feed during the three or four hours in which the change is being made; (6) keep up a little wood smoke in the room; (7) give a few scanty meals of light leaf; and (8) diminish the temperature a little. AE ns “a0, NI CALCINO, OR MUSCARDINE. This disease, at first, has no visible appearance, but by degrees the vitality of the worm is impaired, and it eats and moves slowly. The body turns rose-colored or red, beginning with the stigmates, and then contracts and loses its elasticity, after which the worm stands still as though paralyzed, and finally dies 20 to 30 hours from the appearance of the first symptoms. After death the body dries up and is covered with a white efflorescence, causing it to look like a stick of white chalk (fig. 16); hence the name of the disease. Calcino is caused by a mold or minute fungus. There are two varieties of this fungus: Botrytis . bassiana and B. tenella. They both attack the worm in the same way ‘The spores of the mold by chance get on the body of the worm when it is in a molting condition, and there take root, pene- trating below the skin. The thread-like mycelium ramifies until it fills the entire body. Later some Fic. 16_Calcinated worm. Of the branches fructify on the surface, and the (Redrawn from Verson fruit bursting envelops the worm with innumer- and Quajat.) : : able spores resembling a white powder. Each spore is capable of settling on a molting worm and giving it calcino, hence the necessity of taking steps to avoid contagion. Cal- cino is more contagious than other silkworm diseases. Darkness, stagnant air, dirt, warmth, and moisture are the five things that favor mold, and calcino is a mold. 165 32 The chief cause of the disease is neglecting to change the beds and keeping litter in and around the room. When only one or two worms have died from calcino all the shelves should at once be cleaned and divested of dead worms. The floor should be washed with a solution of sulphate of copper (1 to 200 by weight), and a pound of sulphur should be burned, or a strong wood smoke created in the room, which should then be shut up five or six hours, after which the worms should be fed. Should any worms die the next day the beds should again be changed and an ounce of sulphur burned. The quantity of sulphur fumes that would kill rats, bats, and lizards and even human beings does no harm to silkworms. No hesitation, therefore, need be felt in fumigating the rearing room with sulphur; but eggs and thread nets must not be subjected to sulphur fumes. Silkworms affected with calcino die before the moth stage; therefore, it is impossible for the disease to be hereditary. But loose spores of the mold creating the disease may get on healthy eggs. These may be washed off by a good bath of fresh water. Some recommend a bath with a solution of sul- phate of copper (one-half per cent of copper). In cases of calcino the room should be disinfected immediately after the cocoons are gathered and the paper and brush used should be burned. As calcino is never due to infected eggs no attention need be paid to the presence of spores of the Botrytis in the microscopic examina- tion to select eggs. GRASSERIE. Silkworms having this disease become restless, bloated, and yellow. If punctured they exude a purulent matter full of minute polyhedral, granular crystals. Grasserie is neither hereditary nor contagious. Unlike pebrine, flacherie, and calcino, it is not caused by microbes capable of multiply- ing and creating plagues. Grasserie does little harm to silkworms in, Europe, but in warm countries, as in Bengal, sometimes assumes an; epidemic form. Worms first fed on mature leaf, and afterward on young leaf, are’ apt to take grasserie. The propagation of large trees is the best means of checking the disease. The main cause of the sporadic appearance of grasserie is mismanagement of the worms at the molting periods. Feeding should not be stopped before all the worms have begun to molt, and should not be recommenced until all the worms are well out of the molt; otherwise they are likely to have grasserie. This disease often leads to flacherie, and when it occurs in an exaggerated form indicates latent pebrine. 165 O U.S. DEPARTMENT OF AGRICULTURE, FARMERS’ BULLETIN No. 165. SILKWORM CULTURE. HENRIETTA AIKEN KELLY, Special Agent in Silk Investigations, Division of Entomology. [REVISED BY C.J. GILLISS.] =? WASHINGTON: GOVERNMENT PRINTING OFFICE. 1903. LETTER OF TRANSMITTAL. U. S. Department oF AGRICULTURE, Division oF ENTOMOLOGY, Washington, D. C., March 5, 1903. Str: I transmit herewith an article on silkworm culture, prepared by Miss Henrietta Aiken Kelly, special agent in silk investigationsof this Division, and recently published as Bulletin No. 39 (new series) of this Division, to which has been added a few paragraphs of infor- mation on the culture of the mulberry, condensed from Bulletin No. 34 of the Bureau of Plant Industry. : Miss Kelly has studied the culture of the mulberry silkworm as car- ried on in France and Italy for a number of years, has consulted the works of the best European authorities, and is therefore well qualified for this task. Although the silkworm industry has not attained much commercial importance in the United States, there is a popular demand for information on the subject which, it is believed, can be supplied to the best advantage by the republication of this matter in the popular Farmers’ Bulletin series. Respectfully, L. O. Howarp, Entomologist. Hon. JAMES WILSON, Secretary of Agriculture. 2 165 S06L ‘LI waquiada(T ‘aungnabp fo hwnjaioeg! ‘NOSTIM SHNVE TY ‘ADOTOWOLNA jo nwaung ‘'SUNLINOIYDY JO LNAWLYVd3ad S3LVLS G3LINN - saa “noaung fo Jay ‘aduvMOH ‘O “TI WOLNGLISIP 1OJ SoS OU SBIT PU suvout [je : ] 7 : , SILKWORM CULTURE. The caterpillars of many moths and of a few butterflies produce silk, but certain of those belonging to the family Bombycidae, or true silk- spinners, particularly Bombyx (Sericaria) mori, or the mulberry silk- worm, yield the most and the best silk. The races of Bombyx mort to-day are the result of domestication and artificial rearing, and the wild type is uncertain, though most authorities assign the foot of the Himalaya as the cradle of the mulberry silkworm. It has been indus- trially cultivated in China from time immemorial, and in Europe since the sixth century. THE LIFE OF THE SILKWORM. Like all insects of its class, before arriving at the perfect winged state, it exists (1) as a caterpillar or larva, and (2) in a chrysalis state. Td 4 7. de sees i et 49 ete ON ee "i ; : fk ia 5 : : ; { i i i is tt tt thie © | R Fig. 1.—Adult silkworm: 1, head; 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, rings; 11, horn; 13, 3 pairs of articulated legs; 14, 4 pairs of abdominal or false legs; 15, a pair of false legs on the last ring. THE LARVA, OR CATERPILLAR. The larva (fig. 1) has a cylindrical body composed of 12 rings; each of the first three has a pair of jointed legs, and the sixth, seventh, eighth, ninth, and twelfth each bears a pair of false legs, destined later to disappear. The black elliptical spots on the side are the orifices for breathing, and are called stigmata or spiracles. The head is a small mass covered with a hard scale, and is provided with jaws that move laterally, like the wings of a folding door. The alimentary canal extends throughout the entire length of the body, 5 165 6 and on each side of it is placed a silk gland (fig. 2). These consist of two whitish or amber-colored cords, which after innumerable curves unite in the spinneret in the region of the mouth. There are also two glands, whose excretory canal opens in the spinneret, and covers the silk as it comes out with an impermeable varnish rendering it insoluble in acids and alkalies. This varnish is about a fifth of the weight of the thread. Hatchings usually occur annually in the spring. Simple contact with the air causes the new-born insect imme- f diately to acquire a volume larger than it had WPF in the egg, and it quickly begins to gnaw the [ under surface and edges of the mulberry leaf. It eats day and night at all hours, except when ef | asleep, and in about thirty days grows 14,000 times larger than it was at birth. As the silkworm grows larger it becomes paler in color, because its dark chestnut brown hairs are scattered over a larger surface, thus showing more of the true color of the skin. About five days from its birth the vitality of the larva decreases, and it eats scantily or not at all, and becomes thin and whitish in color. Then it moves around unquietly, and finding a we convenient place attaches itself to it, holding on by its false feet. It thus remains motionless, ~ with the front part of its body raised up, for a if period of time varying according to tempera- & ture,and takes its first so-called ‘‘sleep,” or molt, A) during which time the body undergoes extraor- pate cttion sr inary modifications. The skin is entirely shed, glands which secrete the and all the tissues that can not keep up with the ease ce canal; f spin. Tapid growth of the insect are changed. neret; g, accessory glands | The scale which covers the snout is the first Sea from Verson and art of the case to fall, and a new case appears jat). under the former one. The worm then pushes itself forward through its first ring, sets at liberty the legs of the thorax, and by a wriggling movement comes out of its old sheath. To facilitate this difficult change a liquid is secreted between the old skin and the one forming beneath it. The life of the larva is usually divided into four ages, varying in length according to temperature, frequency of feeding, race, and the robustness of the worm. The following is about the average: First age, from birth to first molt, five to six days. Second age, from first to second molt, four days. Third age, from second to third molt, four to five days. Fourth age, from third to fourth molt, five to seven days. Fifth age, from fourth molt to maturity, seven to twelve days. 165 z Some time after each molt, perhaps the time needed to regain lost strength and to solidify the newly-formed organs, the worm remains in a state of relative torpor. Not much practice is needed to recognize when it has come out of its ‘‘sleep.” It moves its head and thorax, which are whitish, while the rest of the body is gray, and has com- pletely lost the shining aspect which it had when the worm began to molt. When fairly through its first molt the larva begins again to eat, and its hunger does not cease until it is ready for a new molt. Four molts having been made, the worm eats a prodigious quantity of leaf until it reaches its maximum growth, when its appetite diminishes and ceases altogether. It then stops moving and remains for some time in repose, evacuating, meanwhile, its digestive canal, thus losing up to 12 per cent of its weight. Its lean body is now white or yellow, according to the race, and semitransparent. Very soon it begins to move about again, lifts up its head, which is longer and more pointed, and turns in every direction seeking to find a convenient angle, finding which, it throws out a silk thread from its spinneret. First a net is formed to hold the cocoon which is to be spun, then the regular spinning begins and the form of the cocoon is designed. For some time through the veil which very soon is to sur- round it, the diligent larva, with its back turned outward, may be seen completing its task. It is calculated that with its head alone the silk- worm makes 69 movements every minute, describing arcs of circles, crossed in the form of the figure 8 (fig. 3, a). Meanwhile the web grows closer and the veil thickens, and in about seventy-two hours the worm is completely shut up in its cocoon, which serves it as a protective covering. THE CHRYSALIS. In the cocoon the silkworm goes through the last phase of its larval life. After four or five days the skin breaks, and the insect. which Fie. 3.—The chrysalis: a, silkworm completing its cocoon; 6, cocoon and chrysalis—cast-off skin of larva beneath; c, back view of chrysalis; d, side view of chrysalis. (Redrawn from Maillot.) issues from this old covering is the chrysalis, whose weight is often only half that of the larva at its highest development (fig. 3). 165 8 The chrysalis seems to have neither head nor feet, is golden-colored at first, and then turns chestnut brown. The skin dries rapidly and forms a hard case, on which the lines of only the posterior rings are seen, the place of the first three rings being covered with the wing-cases. The chrysalis state is in certain respects a sleep and in others a period of great activity, in which the entire being is transformed. Wings, antenne, reproductive organs, and legs are all now developed. This state lasts from eighteen to twenty days, according to the temperature. When the metamorphosis is complete, the sheath breaks in the region of the head and the moth or perfect insect issues. THE MOTH. The larva in spinning the cocoon leaves one end less dense, so that the threads open freely to permit the egress of the moth. By the aid of an alkaline fluid the moth sof- tens and parts the threads and lib- erates itself. The moth (fig. 4) comes out of the cocoon, as the larva out of the egg, in the early morning hours. It has a distinct head, thorax, and abdomen, four wings, two comb-shaped antenne, three pairs of legs, and a pair of compound eyes. Shortly after emerging, the moth deposits a liquid substance, generally white, sometimes color- less and sometimes reddish, and then the union occurs, lasting sev- . eral hours, after which the eggs are laid either immediately or in the course of four or five hours. A gelatinous substance supplied by two glands near the extremity of the oviduct covers the eggs as they come out, and causes them to adhere to the substance on which they are laid. The laying, consisting of 300 to 700 eggs, is generally completed in three days, 70 to 80 per cent being deposited the first day, 20 to 30 per cent the second day, and a few the third day. The mother moth dies six to twelve days later, her death being usually preceded by that of the male. Death occurs more or less speedily, according to the robustness of the moth, the temperature, and the tranquillity in which it has been left. - Thus in about sixty-five days the silkworm has completed its cycle of existence, its three periods being thirty to forty days in a larval 165 ; Fie. 4.—The moth: a, the male; b, the female. 9 state, fifteen to twenty days as a chrysalis, and eight to twenty days as a moth or perfect insect. The rapid development of the silkworm and its marvelous transfor- mations indicate extraordinary power and very active functions. Its respiration is almost equal to that of the frog and of certain large birds, and it must be always surrounded by plenty of pure air, THE FOOD OF THE SILKWORM. The leaf of the white mulberry is the natural and the best food for the silkworm. There are many varieties of the white mulberry—some much better adapted than others to commercial silk culture, and some better suited to certain localities. CULTURE OF THE MULBERRY. As the securing of a food supply is a necessary condition to silk- worm culture, some information on the culture of the mulberry, con- densed from a bulletin of the Bureau of Plant Industry, @ is inserted: Of the mulberry there are many so-called species and a great many varieties, but there are only one or two species and a few varieties which are of importance in silkworm propagation. Chief among these for producing silkworm food is the white mulberry, Morus alba. This is thought by some to bea native of China. It is hardy over a large area of the United States. Most of the silkworms reared in China are said to be fed upon Morus multicaulis. This mulberry was largely planted in the United States many yearsago. Few, if any, of the original trees remain, but specimens which are thought to be wild seedlings of these are very plentiful in the Southern States. These trees are thoroughly accli- mated and free from disease. Itis therefore probable that there is now in the United States an abundant supply of material for propagating purposes, at least. The white mulberry, under good cultivation, is a low-growing tree, seldom attaining a greater height than 25 or 30 feet. It will reach this height in a comparatively few years after planting. In the vicinity of Washington the trees flower about the middle of May and ripen their fruit during June. The mulberry may be propagated by means of seeds, cuttings, layering, grafting, and budding. Seeds and cuttings are, however, the least expensive and trouble- some, and the most satisfactory means of propagation. Propagation by Means of Seeds.—This is the most convenient and rapid method of propagation. To remove the seeds from the berries, place them in a large bucket or a tub and squeeze them with the hands until they form a jelly-like mass. Add water and stir well to allow the seeds to sink to the bottom. The water and pulp can then be poured off, and the seeds can be dried by exposure to the air. The seeds may be planted at once, or they may be kept over winter and planted in thespring. Beds about 5 feet wide should be thoroughly prepared. The seed should be sown broadcast, not too thick, as crowding makes weak plants. Press the seeds in with the back of a spade and cover lightly with fine soil. For protection from the heat of the sun, over the beds should be placed lattice-work screens made of lath, and over these canvas should be spread until the plants show above the ground. After that the canvas is unnecessary except in the hottest part of the day. With spring-sown seeds the lath screens without canvas will be sufficient. 4Bul. No. 34, Bureau of. Plant Industry, U. 8. Department of Agriculture. By George W. Oliver. 4389—No, 165—06——2 10 Seedlings vary considerably from the parent tree, and many of the seedlings grown will be found to have leaves of undesirable quality. Hence careful selection should be practiced and many of the seedlings must be rejected. The Use of Cuttings.—For propagation by means of cuttings in the summer time, selected seedlings which have made considerable growth may be used. Two or three leaves clipped to half their length should be retained on the cutting (fig. 5,a.) The cuttings should be set sloping in beds of moist sand in a cool propagating house, or, if such is not available, in a cold frame with northern exposure; if in the shade of trees, so much the better. The sash should be kept closed to conserve the moisture of the atmosphere until the cuttings have taken root. When considerable root growth has been made they should be transferred to beds in the open, being placed 6 inches apart each way and well watered until estab- lished. The supply of winter cuttings should come from dormant wood taken from the trees just after the leaves have fallen. The cuttings (fig. 5, 6) should not be less than one-fourth inch in diameter and should be about 10 inches in length, the top cut being made about a half inch above a bud. The cuttings should be tied in bundles of 50, and these may be buried in moderately moist sand or ashes until spring, when they can be put out in rows in well- prepared soil. These nursery rows should be well cultivated and kept clear of weeds. Another method of propagation from cuttings, and a very success- ful one, consists in selecting me- dium-sized shoots about the begin- ning of November. These, before being made into cuttings, are sorted into bundles of different lengths, tied, and heeled in ashes or sand, or in a mixture of both, and protected by a frame having a Fie. 5.—Mulberry cuttings: a, a summer cutting; b, b, win- northern exposure. During the euRsGee winter they are taken out and cut into lengths of about 5 inches. These are tied in bundles and buried in moist sand or moss. In early spring they are untied and put quite thickly in a propagating bed having a mild bottom heat, where they will root rapidly. When such a bed is lack- ing, wooden flats about 4 inches deep may be used, but they must have the protec- tion of a frame covered with sash. If a little loamy soil is placed in the bottom of the flats the cuttings will remain in good condition fora considerable time after root- ing and until a favorable opportunity arrives for planting them out in nursery rows. Planting.—The mulberry grows well in a great variety of well-drained soils. The young trees should be transferred from the nursery to their permanent places either 165 11 in the fall or in the spring. If in the fall, the transplanting should be done when the leaves have matured or fallen. In the spring transplanting may take place as soon as the ground is in good workable condition. The ground should be deeply plowed and thoroughly harrowed. If the ground is hard and the soil poor, large holes should be dug and filled with good soil as the trees are planted. In trans- planting the roots should never be allowed to get dry. When taken up they may be immediately dipped in a mixture of soil and water and then kept covered until planted. The distance between the trees should not be less than 10 feet each way. If the grove is to be large, wider spaces should be left at intervals, so that wagons may be driven through. Pruning.—Pruning is best done in the fall or winter. The central part of the tree should be kept open to admit light and air. The low, spreading form of tree is much the best, and this form is secured by systematic pruning, which is begun by cutting the young tree back one-half in the fall after it is first planted out. Afterwards three or more strong shoots should be selected to form the main branches, and, if necessary, these may be prevented from growing upright by means of sticks fastened between them in such a way as to force them to spread apart. In gathering the leaves always allow enough to remain on the tree to insure its perfect health. If some of the trees show signs of failing vigor as a result of excessive leaf gathering, it is advisable to allow them to grow for a season without picking, and by early pruning out of unnecessary growth permit those growths which are desirable to become ripened. Restricting the height of the trunk of the mulberry to 5 or 6 feet makes it possible for old women and children to gather leaf, thus diminishing the cost of labor one-half, a most important point in commercial silk culture. It is also important to cultivate trees that bear little or no fruit, for the production of fruit not only consumes part of the strength of the tree, but much labor is involved in being compelled to divest the branches of fruit before they can be used as food for silkworms. The stump mulberry, or that growing low like a shrub, the hedge mulberry, and that which grows along walls vegetate much earlier than the medium and high trunk trees. Silkworm rearers should always have a ready supply of leaf for the first ages of the worm, and especially is this necessary if early cultures are desired with a view to escaping the heated days of May and June. AMOUNT OF LEAF AND PREPARATION. The race, the size of the worms, the variety and age of the mulberry, the nutritive quality of the leaf, the year, the season, and the climate make the requisite quantity of leaf very variable. The following is given as a basis of calculation, all circumstances being considered, and the leaves not being cleaned: For the larve hatching from 1 ounce of eggs, during the first age, 11 pounds of leaves; during the second age, 26 to 33 pounds; during the third age, 88 to 145 pounds; during the fourth age, 264 to 352 pounds; during the fifth age, 1,540 to 1,760 pounds; or about 2,200 pounds in all, of which one-half is consumed in the last six or seven days of the fifth age. 165 12 The age of the leaf should be relative to that of the worm. Young worms fed on gld leaf, or old worms fed on young leaf, are apt to become diseased, and even though they may not die, will scarcely molt or will spin indifferently. A change of leaf, too, should, if pos- sible, be avoided, or made gradually. Fresh leaf only should be used, and never when wet with dew or heated, or before it has in a measure acquired the temperature of the room in which the worms are being reared. It should be gath- ered early in the morning or in the evening and should not be bruised or torn, nor should the baskets or aprons used to carry it be the same which are used to remove litter. To avoid fermenta- tion the leaves must be spread out in a cellar or cool, darkened room. Cut up only a limited quantity of leaf at a time and cover with a damp cloth to keep fresh, but never submerge the leaf in water, as this is apt to occasion flacherie, a very destructive disease. From the fourth age on there should always be a day’s supply ahead, so that in case of rain the worms will not have to fast. In gathering leaf, always strip the branches from base to top, so as not to tear the bark and injure the new buds. The sacks for holding the leaves should have a hoop around the opening and a hook to sus- pend them to the branches. Fia. 6.—Light movable shelves. IMPLEMENTS NECESSARY TO SILKWORM CULTURE. Commercial silk culture requires a smaller outlay of capital than almost any other industry. The net gain the first year may pay for an outfit which will last for many years. The following articles are indispensable: (1) Some very light movable shelves, open to air, for the first ages; and, for the following ages, latticed shelves about 33 feet wide, and stands to support them. (2) Unsized ordinary wrapping paper or newspapers to cover the shelves. (3) A small ladder, if necessary, to reach high shelves. (4) Small trays to remove worms. 165 13 (5) Knives to cut leaves and baskets to distribute them. (6) Coarse tulle and nets or perforated paper for changing beds and equalizing the worms. (7) A supply of brush, straw, or shavings to construct the spinning place. (8) A thermometer. Wire, twine, laths, or canes are suitable for the lattice work of the shelves. Make the space between the shelves about 14 inches. If TINT OOTY Fie. 7.—The rearing room (after Gobin). possible, do not arrange the shelves along the wall, and allow a good passage between the tiers of shelves (figs. 6 and 7). SILKWORM EGGS: HOW TO WINTER AND HATCH THEM. There are two kinds of silkworm culture: One for production and one for reproduction. The object in the first case is to get the greatest yield of cocoons, and with a little training, may be carried on by anyone of ordinary intelligence. The object in culture for reproduction is to secure eggs free from hereditary taint of disease, and experts only can be depended on to conduct it. Besides a careful physiological examination through- out the rearing, the body of the mother moth is microscopically tested after death, and her eggs are not retained if signs of disease are discovered. In this way the birth of healthy worms is insured. Pasteur first applied this method of selecting silkworm eggs, and thus checked the plague (pebrine) which was rapidly destroying silkworm culture in Europe. 165 14 Formerly, through an indiscriminate use of eggs, disease invaded the rearings to such a degree that from 65 to 90 pounds of cocoons was considered a good yield per ounce of eggs. At the present low price of silk such cultures are no longer remunerative, and industrial silk culture now demands the exclusive use of scientifically tested eggs. The grainage, or preparation of eggs for market, constitutes a special department of silk culture. In Italy there are over 400 establish- ments which supply eggs to raise the annual silk crop. The poorest peasant, though well skilled in the art of rearing silkworms, would not risk a rearing with eggs which have not been selected and pre- served by experts. The eggs of crossed races are best for culture with a view to pro- duction of silk, and here, as much as in the examinations which have been referred to, the knowlege of experts is needed. The life of the egg, in those races which have but one generation each year, has three phases, the first lasting about three months, full of activity; the second lasting from about October to the middle of Febru- ary, one of inactivity, in which there are no signs of life; the third from the middle of February to the moment of hatching, in which the vital activity recommences, and the germ begins to organize as soon as the temperature rises a little above 50° F. The measure of the activity of the egg, in this stage, is the measure of its danger, for any sudden change of temperature would injure or destroy the delicate embryo, or cause the larva to be born before its food was ready. To guard against such accidents, eggs must be wintered in a high region or ina refrigerator at a uniform temperature of about 35° F., from December 15, until the mulberry begins to bud or until hatchings are desired. There should always be good ventilation, the air should not be moist, and great care must be taken to keep the eggs out of the reach of mice and insects. Natural hatchings are almost always irregular, extending over eight or ten days, thus multiplying the divisions and rendering the rearing difficult and costly; hence, the necessity for artificial incubation. Eighteen days before the time decided on for the hatching, spread out the eggs in thin layers in the incubating room or incubator. The temperature should be 55° F. From the fourth day on, gradually increase the temperature two degrees in twenty-four hours until 73° F. is reached, when, at this uniform temperature, hatchings will occur in ten days on an average. This period, however, varies from eight to fifteen days, according to race, the cold supported during the winter, the first grade of heat, and the highest during the incubation, and the number of days taken to pass through these two grades of heat; and also according to the humidity. To obtain a good and complete hatching, a slight humidity 165 15 is necessary, especially during the last four or five days. To secure this keep an open vessel of water near the fire, or sprinkle the floor with water occasionally. The temperature may be raised during the hatching to 75° F., but sudden changes of heat must be avoided, and, unless the newborn worms can be kept in the same temperature, it is dangerous to have the maximum temperature of the incubator so high. It is better for the period of incubation to be protracted than sud- denly shortened. Holding the eggs at a certain temperature, or slowly lowering the temperature a little does no harm. When the season is not propitious, the hatching may in this way be retarded. An incubating room is preferable, because it also serves for the first two stages of the worms, but in small rearings an incubator is more economical, both with regard to service and to fuel. For a large quantity of eggs (5 to 10 ounces) a small incubator, which is very much used in chemical laboratories to dry substances, is reeommended. Any ordi- nary tinsmith can make it. It consists of a double case, cubical in form, with a zinc bottom. The space between the outer and inner walls is filled with water. The front face of the cube is furnished with a glass, so that the temperature within, indicated by the thermometer hanging on the glass, may be seen with- out the necessity of opening the incu- bator. There are two openings below on opposite sides to allow the cold air to come in, and an opening in the center of the top to permit the outward flow of the heated air. Having filled the space between the walls with water through the pipe, the incubator is placed on a support and heated by means of a gas or oil lamp to the desired degree, and, by raising or lowering the flame, a constant or progressive temperature can be maintained (fig. 8). A self-regulating incubator, such as is used to hatch chickens, would be more convenient, but would cost more. The whitening of the eggs denotes the near approach of the hatch- ing. Double pieces of tulle or sheets of perforated paper sprinkled over with finely cut-up white mulberry leaves should then be lightly placed over the eggs to allow the outward passage of the worms as soon as hatched. The object in employing two pieces of tulle or paper is to prevent the unhatched eggs which cling to the sheet from being removed with the newborn worms, This process must be 265 Fia. 8.—Hot waterincubator. (Redrawn from Verson and Quajat.) 16 repeated daily during the hatching, the second sheet always being renewed. The duration of the hatching varies from three to five days, the eggs hatching about as follows: During the first day, 5 per cent; during the second, 33 per cent; during the third, 50 per cent; during the fourth, 5 per cent; during the fifth, 7 per cent. Twenty-five grams of eggs will give about 17 grams of worms. In small rearings most cultivators raise only the worms that are hatched on the second and third days, to avoid the necessity of forming too many classes. The worms must be classed according to the date of birth, and the insignficant number hatched on the first and last days ‘scarcely compensate for the trouble of rearing them. Different races must also be reared separately. Where several in one neighborhood are engaged in silk culture it greatly reduces the cost to have all the eggs hatched in one incubator. The person best acquainted with silk culture can undertake the incu- bation, and distribute the young worms on the second or third days to those who are to rear them. This is the plan adopted among the Italian peasantry, the wife of the supervising farmer hatching the eggs for whole villages. THE REARING OF SILKWORMS. Before entering into the details of a rearing some general directions must be given concerning the rearing room—the heating, ventilation, and disinfection. GENERAL DIRECTIONS. The place chosen for a rearing should be relatively high, and not exposed to malaria or bad odors, and mulberry trees should grow around it. Any room that can be properly heated and ventilated will answer the purpose. An open fireplace is the best means of heating, but is expensive, as much of the heat is lost. Hot-water pipes, such as are used to heat a greenhouse, are good for a building specially built for silkworm rearing. Iron stoves should not be used, unless placed in an adjoining room with communicating pipes. Never employ charcoal as fuel. Ventilation.—The domesticated worm should be surrounded contin- — ually by pure air. The amount of carbonic-acid gas given out by the worms and their attendants is very considerable; besides this, a quantity of deleterious gas is generated by the litter of the beds, and the lights and fires consume a great deal of oxygen. Myriads of spores and germs of organic life float in the air of the rearing room, and their influence paralyzes the vital energy of the skin and of the organs of respiration, on whose normal functions the robustness of the worm so much depends. Hence, it is evident that the quantity of 165 : 17 vitiated air which should be expelled from the room requires the introduction of a large quantity of fresh air. For this, a double system of ventilation is necessary, which may be obtained by double openings in the windows, to allow the heated bad air to pass out above and the cool fresh air to come in below. To renew the air in every part of the room, and to avoid a single and often violent cur- rent, there should be more than one window. An open fireplace is the best means of ventilation. When the difference between the external and internal air is slight, or there is no difference at all, arti- ficial means must be used to create a current. Light and frequent fires, or a burning lamp in the fireplace, or a revolving fan, may be used to prevent stagnation of the air. Disinfection.—EKight or ten days before introducing the worms into their quarters all the shelves and implements should be washed in a solution of chloride of lime (11 pounds of chloride of lime to 88 quarts of water), or in a solution of sulphate of copper (1 to 100 by weight). When everything is in order—tools, perforated paper, material for the worms to spin their cocoons on, etc., each in its own room—close the doors and windows as tightly as possible and fumigate the rooms with sulphur (11 pounds of sulphur to every 100 cubic yards of space). To fumigate properly, powder the sulphur and place it in an earthen or metallic vessel over a slow fire. The sulphur will gradually melt and take fire. Place it immediately in the rearing room and leave it, with the doors and windows completely shut, for twenty-four hours. Nets should not be exposed to sulphur fumes, for this would soon rot them, but should be washed in a solution of sulphate of copper, and immediately afterwards in plain water. Twenty-four hours after the fumigation the floors should be washed with a solution of chloride of lime or sulphate of copper, and the walls should be whitewashed with lime. When dead worms are seen on the shelves, change the beds and create in the rearing room sulphurous gas by burning a pound of sulphur during six hours, or make a strong wood smoke, which is a good disin- fectant and will not harm the worms. Precaution having been taken to destroy germs of disease in the rearing room, the new-born worms may now be safely installed there. Space Required.—The worms from 1 ounce of eggs should cover at birth 1 square yard. Doubling this space on the fourth day, they would require 2 square yards, and at their change of beds after molt- ing, 4 square yards. By the spacing of the third day of the second age, and the doubling of beds preceding the second molt, they will need for the second age 8 square yards. For the third age 16 square yards will be required; for the fourth age 32 square yards; and for the fifth age 60 square yards, The more space that is accorded to the 165 18 worms in their first ages, the more robust they wil be; and if the space can be tripled instead of doubled during the fourth age, and for the fifth age be 70, 80 or 90 instead of 60 square yards, the harvest of cocoons can be raised from 60 kilograms to 70, 80, or 90 kilograms per ounce of eggs, the quality of silk also being superior. Temperature.—The silkworm is not a tropical insect, and attains its best development between the temperatures of 68° and 77°F. It is safe to adopt the mean between these two temperatures for the general rearing. Each cultivator, however, may suit his convenience, remem- bering that to fall below or to exceed the mentioned limits of heat is detrimental to the worm, and will affect the quantity and the quality of its spinning. From the second age the temperature should be from 70° to 72° F. and should be kept as uniform as possible to the end of the rearing. The time which elapses between one change and the following one may be much shortened by raising the temperature and feeding oftener. Such hasty rearings may be made in twenty-two to twenty-four days. They are, however, to be condemned, as contrary to the nature of the silkworm. Meals folowing each other too closely can not be properly digested, and are likely to cause disease. Besides, hasty rearings require more labor, and the service must be kept up night and day. As there is danger in too high a temperature, so there is danger in one that is too low (64° to 68° F.). A rearing that is too prolonged, lasting over thirty-two days, is to be avoided to escape the heat of June, under which the beds are more likely to ferment, causing disease; the worms have less appetite and leave more leaf from one meal to another; the changes are slower and less likely to occur instantane- ously; and there is more risk of muscardine or calcino, a disease due to a mold. Both hasty and tardy rearings are, therefore, to be proscribed, and those conducted in twenty-eight to thirty-two days alone are recom- mended. This lapse of time permits the leaves of the mulberry to acquire maturity, and the growth of the worm should be relative to that of the leaf on which it feeds. THE FIRST AGE. Hatchings usually occur early in the morning. The worms which have crawled up through the holes of the tulle or paper to get food, should not be removed before 10 a. m. to the latticed shelves covered with paper to receive them. Each shelf must be marked with the date of the birth of the worms put upon it, and care must be taken to place on the same shelf only worms born on the same day, as a remu- nerative rearing demands that such alone be raised together. Should the hatching occur at 68° to 70° F., keep this {ern poLatirs during the first ages, and feed eight times derue twenty-four hours; if 165 f : 19 the temperature at birth is 75° to 77°., slowly diminish the tempera- ture one or two degrees, and feed ten times in twenty-four hours. The appetite of the worm increases or diminishes with the heat. The second day, in case of the worms hatched at the maximum, adjust the temperature to the degree proposed to conduct the rearing. In feeding sprinkle finely cut up tender leaves frequently over the worms, and toward the fourth day begin to regulate the number of meals so that it will range from four to eight, according to the temperature. Before cutting the leaf remove the stems. Distribute the leaf uniformly and equally on the shelves, in order to prevent the worms from crowding more on one side than another, and in order that they may be equally nourished and make their changes simultaneously. Cut only a small quantity of fresh leaf at a time, and keep the rest in jars or baskets covered with a damp cloth. Never submerge the leavesin water. For the first two or three ages, the white ungrafted mulberry is recom- mended, it being lighter and more digestible for delicate worms. It is well during the feeding to open the door and windows to insure a good supply of fresh air. After feeding, close the door and windows, unless the day is warm, when they may be permanently left open, pro- tected by curtains through which the air passes freely. The worms should never be exposed to direct sunlight or to a strong current of air, and during a thunderstorm the windows and doors should be closed. Worms of the same age and development should be classed together. To obtain this equalization, do not feed newborn worms until all that have been hatched on one day have been removed to shelves, then give a general meal. If at the end of two or three days it is noticed that on certair shelves there are smaller worms than on others, in order to allow the less developed worms to catch up with the more advanced ones, place the former nearer the fire or on the highest shelves, where the air is warmer, and give them one or two more feeds than the larger worms. For this reason it is well to have light movable shelves. Many cultivators of silkworms do not change the beds during the first age, and it is not absolutely necessary, if the leaf has been well cleaned of stems and very finely cut up, and, aboveall, if the airisdry. Change of bed, however, must be made if the litter is damp, and the weather rainy, for the worms are going to molt in two or three days, and this crisis should not occur in unhealthy conditions. It is always more prudent to change beds on the fourth day, and is, therefore, advised. : The space occupied by the worms must be doubled when the change of beds is made. é The bed on which the leaf and excrement accumulate is, perhaps, the greatest source of danger to the worms. When there is not a free circulation of air, gases are developed which almost always cause fer- mentation, paving the way for future disease. Hence the necessity for frequent change of beds. This is made in various ways. The 165 20 5 practice of doing this by hand is to be condemned because it consumes too much time and is apt to injure the worms. Thread nets (fig. 9) and perforated paper are the best means to employ. They save two- thirds of the hand labor, and thus allow beds to be oftener renewed, which is a most important consideration. In the first age tulle or mosquito net may be employed instead of nets or paper. The manner of proceeding is as follows: Place the last meal at night on the nets and extend them over the worms. By morning tks worms will have mounted above the opening in search of fresh leaf. Then lift up the nets, beginning at the top shelf, and place them on clean shelves. Carefully detach from the nets any portion of the old bed, and, if the worms are not molting, gather up the few worms that have remained behind, and tenderly place them with the others. The change of beds is thus rapidly effected with the least labor. It is very important that the tension of the net be such as to prevent the worms from being crowded together in the middle. Perforated paper (fig. 10) is another means often used to effect change of beds; but it does not allow the worms to mount with the same facility. It is also apt to break when the worms become heavy, and in many cases it has to be renewed annually, so, in the end it is no cheaper than nets. In changing beds, do not feed the worms that are first taken up until all from the old bed have been removed; then give a general meal, for all the worms born on the same day and forming one class should have the same num- ber of meals to preserve their equality of growth, which is necessary for a successful rearing. Having adopted hours for feeding, these should be adhered to throughout the rearing. When four meals are given, the best hours are 5 to 6 a. m., 10 to noon, 3 to 6 p. m., and 9 to 11 p. m. Toward the sixth day worms begin to eat less. This is a sign that they are going to molt. Then another change of beds and doubling of space are necessary. The molt or change of the worm is easily recognized by a swelling of the head, whitening of the skin, transparency of the body, and a fixed position. 165 Fic. 9.—Net used in changing beds, 21 To change the beds, proceed as before, only leave undisturbed on the old beds the worms that are molting. When all the tardy worms have been taken up and placed on shelves, give them frequent sprinklings of finely cut up leaf to enable them to catch up with the worms already molting. Diminish the feeding as the backward worms begin to molt, and cease feeding entirely as soon as a single worm comes out of the molt. Then wait twenty-four hours so that the worms may be well over the change before giving a general feed. In this way the equality of development necessary for a methodical and successful rearing is maintained. A fast of twenty-four hours will not hurt the advanced worms, while the extra feeding given to the backward ones may enable them to become equal to the former. \\ \ Cons WN 3 AN i YN SSS Za eo Fic. 10.—Perforated paper used in changing beds in the second and third ages. The beds or the worms on the old litter may be changed when the general meal is given. Many cultivators do not change the beds and double the space until after the first molt, allowing all the worms to change in the same bed. In this case, owing to the distribution of leaf for one or two days after the molting has begun, the molting worms are covered by a more or less thick coat of litter, and exposed to emanations of bad gases in a critical period of life, which is likely to cause disease. Besides, in the first age, the worms are so small that they are likely to be lost in the litter, or to perish from suffocation. Hence, it is healthier to change beds and double the space before the molt. 165 22 THE SECOND AGE. The coming out of the molt is announced by the appearance of a small triangular-shaped livid spot on the worm’s head, and the changed skin is grayish in color. The worm takes several hours to recover from a change; then it begins to search for food, which, however, as before stated, must not be given before all the worms have recovered from the molt. Then a slight meal is given by means of perforated paper or nets. ‘The worms crawl up promptly and can be easily gathered up and placed on fresh shelves. If the two sets of worms recover from their molt at the same time, they may be classed together; if there is a difference of a day, it will be necessary to keep them separate throughout the rest of the rear- ing, for the equality of age has disappeared, and, if they are put together, the second change will not occur simultaneously for all the worms, but will extend over several days, and occasion the greatest trouble to reestablish the equality of size necessary for the best results. In case no worms have had change of bed before the molt, do not recommence feeding until the greater part of the worms are awake. Do not fear that they will suffer from hunger. Then form a new division of those still molting. It is frequently better to have two divisions, but if, to simplify the work, but one is desired, by putting the backward worms on the highest shelves, and feeding them oftener than the advanced set, an equality may be reestablished. Three days after the first molt the beds must be renewed, and at the same time more space must be allowed the worms. The second age is the shortest, being less by two or three days than any of the others. Toward the fifth day of this age the worms begin to molt again. Then act as before—that is, by aid of nets or per- forated paper, remove the backward worms, in order to place them elsewhere, and try by more heat and abundant food to make them catch up with the forward worms. THE THIRD AGE. When the worms are over their second molt they cease to be gray, and take the characteristic color of their race. If they are too long in molting it is because the temperature is too low; that is, below 68° F. Increasing the heat a few degrees will excite the worms and enable them to complete their change. After this the temperature adopted for the rearing must gradually be resumed. The worms double their size in their third age; consequently the space allotted to them must be doubled; that is, they must have 16 square yards instead of 8 square yards, as in the second age. From the second to the third molt the same care is to be given as has been prescribed for the first two ages, except that, if a-small incu- bating room has been used instead of an incubator, the worms must 165 23 ' now be transferred to a larger room to complete the rearing. Care must be taken to heat this room the day before to 80° F., and the next day lower the heat to the degree adopted for the rearing. Feed six times daily either with whole leaves or leaves which are coarsely cut up. For this as well as all the other ages the best rule to follow in feeding is to give only a light sprinkling of leaf at the beginning and end of each age, gradually increasing the ration up to the middle of each age, and then diminishing to the time of a molt. The appetite of the worm will serve asa guide. Give more or less leaf according as the preceding meal has been more or less eaten. In this way leaf will not be wasted and a large quantity of litter will not accumulate under the worms, to their detriment. Toward the sixth or seventh day of the third age, according to the temperature, the worms begin to be languid and lose appetite, as before, and are ready to make a third change. This is the most diffi- cult of all and the one in which they seem to suffer the most. It is also the period when diseases due to bad eggs or to a poor incubation are developed. Excepting accidental diseases, a good result may gen- erally be predicted if the third change is safely passed. With these facts in view, from the beginning of the third age keep the worms sparse on the shelves and see that the beds are dry and changed with scrupulous care, the litter being far removed from the rearing room. Avoid feeding with wet leaf, and to favor the molting raise the tem- perature a degree. It will be noticed that the head and body of the worm are more swollen than in other molts. It is this superabundance of liquid that renders this molt so critical and necessitates a drier atmosphere and a bed which is very dry and not apt to ferment. The worms increase three times in volume after the third molt, and must have space accordingly. They must be separated into three divisions in the following manner: Instead of waiting, as in the first two changes, until half of the worms have begun to molt, let down the nets, or otherwise prepare for the removal of the backward worms when one-third or even less of the worms show signs of molting. About two-thirds will then crawl up on the fresh leaves, and must be placed on a shelf where, after one or two meals, they proceed to molt, being again divided after the first or second distribution of leaves, according to the rapidity of the molting. If only a few worms mount when the first division is made, the oper- ation was delayed too long, and it is unnecessary to divide those first taken up; butafter the change the division of those left on the old bed can be made. To allow the worms to spread out, each division should occupy but one-third of the shelf on which it is placed. THE FOURTH AGE. When all the worms have molted the third time a change of beds must be made as in preceding ages. Do not be in haste to change. 165 24 Wait a few hours to permit the worms to recover their strength a little. The recommendation to feed lightly at first applies especially to the beginning of the fourth age. If the outside temperature is normal, fires need not be kept up, and the doors and windows may be left open, guarded by light curtains. In this age the worms eat enormously and more help will be required to gather and distribute leaf. Small branches of leaf may now be given in place of whole leaves, and the number of meals may be reduced to four, if the temperature is 68° to 70° F., at which temperature the age will last nine days. If it is desired to reduce this age to seven or eight days, raise the heat to 72° F., and give five or six meals daily. Should change of weather retard the growth of the mulberry trees, and temporarily cut off the supply of leaf, adapt the rearing to such a con- tingency by lowering the temperature slowly to 66° or 68° F., and giv- ing only three or even two meals daily. Then, when leaf is obtained, gradually raise the temperature to the degree adopted for the rearing. During the fourth age four changes of beds are made, including the one which follows the third-molt. A single division of the worms is sufficient, which will be the last, and particular care must be taken to divide the worms into two equal parts. For this, spread the nets or perforated paper over the worms when half are molting and proceed as before. THE FIFTH AGE. Do not be in haste to change beds as soon as the worms have molted. This precaution is necessary to allow the new organs to acquire con- sistency, and to prevent worms from being Jost in the litter. Conse- quently, wait several hours, and change beds after the second meal, the first being only a slight sprinkling of leaves. Worms are not strong enough immediately after a change to digest a heavy meal. The space during this age should not be limited. See that between two worms another could be easily placed. Experience has proved that the harvest of cocoons is often in proportion to the space accorded to the worms during this age. Feed from four to six times daily, according to the temperature, and spread the branches or leaves out regularly, not to form a mass. For a simultaneous mounting into the brush all the worms should eat an equal quantity of food. As ripe berries are very indigestible, and also cause beds to ferment, care must be taken to shake the trees well before gathering the leaves, and whatever ripe fruit remains must be taken off before feeding. It possible, change beds daily, especially if more than five meals are given, or if the weather is very warm and damp and there are signs of disease. The first five days after the change the worms grow enormously, and it is very difficult to satisfy their appetite. At the end of this 165 25 time the body suddenly diminishes in circumference, the excrement, formerly dry and firm, now becomes moist and soft, and the appetite diminishes and becomes capricious. This state generally lasts three days, then suddenly the worm ceases to eat, and tries to get away from its food. It prolongs its head, and, changing its former lazy habit of scarcely moving except to get food, runs about in every direction, etepping from time to time, and moving its head (now transparent gold or white, according to race) like a blind person seeking the way. These signs indicate that the worm is hunting a convenient place to spin its cocoon. The worm is now mature, and a spinning place should be ready to facilitate its metamorphosis. The humidity, which always exists at this time on account of the mass of litter, is especially dangerous to the worms; and it is increased if the worms do not all mature and mount at the same time, for those that remain below are wet by the liquid dejections of those that are the first to mount. For this reason do not put worms in the spinning place until they are perfectly mature. They then mount, and crawl around some time seeking a favorable place for their cocoons. Finding this they evacu- ate their digestive canal, and begin to throw around them an irregular net in which the cocoon spun later will be suspended. PREPARATIONS FOR SPINNING. A considerable loss may occur in the spinning place even when the rearing has been most successful. To avoid such loss observe the fol- lowing precautions: (1) Prepare the spinning place in time; (2) arrange it so that the worms may regularly mount, and have abundant room; (83) have it well made, yet economical; and (4) regulate the heat and ventilate the room. — Any convenient dry bushy brush, odorless and free from gum, will serve to construct the spinning place; or if such is not available, bun- dles of straw, or shavings, or finely split up wood may be substituted. Ihe best and most economical arrangement is small bundles of brush or straw placed upright between the feeding shelves, in rows, about 16 inches apart. The bundles are cut a half inch taller than the space between the shelves, and their tops are spread out to form arches, and to allow the worms plenty of room to spin (fig. 11). Branches of elm, oak, birch, etc., are used to place the worms in the spinning place. These branches are spread over the shelves at the end of the ifth age. Very soon they will be covered with mature worms which have ceased to eat, and are turning away from the mulberry. In this way it is easy to select the worms that should be transferred. If the worms are equally developed, in thirty or forty hours they will be shut up in their cocoons. The few that remain behind should be placed elsewhere; fed with fresh leaf on clean beds they will soon catch up with the others. 165 26 The fifth day after the mounting the worms that have not begun to spin should be placed in bundles of twigs and covered with straw or leaves, or putin a basket of shavings, where they will be forced to spin. The temperature during the spinning should be 75° F., and the humidity throughout the rearing about 65°. A good practical test of humidity is a saucer of salt; when the salt is moist, reduce the humidity. Carefully avoid disturbing the worms while spinning, and then, as during all theages, keep the room as quiet as possible. The most scrupulous cleanliness should al- : al ways be observed, both Fic. 11.—Arrangement of spinning places. (Redrawn from Pasteur. ) with regard to the quarters and the attendants; to keep from raising dust, wipe the floor with a damp cloth instead of sweeping it. PREPARING COCOONS FOR THE MARKET. The transformation of the larva into the chrysalis is, according to temperature, completed in from seven to ten days from the time at which the first worm begins to spin. The cocoons are then said to be mature, and this is the best time to gather them. After the removal of the web the cocoons are sorted into three classes: (1) The perfect, (2) the double, and (3) the defective or spoiled. In the United States, the absence of near-by markets makes it nec- essary that cocoons be prepared and stored away, sometimes for months or until they can be used. This preparing consists of killing the chrysalis and then drying the cocoon until no moisture remains to cause ferment and mildew and a consequent rotting of the silken thread. The killing of the chrysalis is usually termed ‘‘ choking” or “‘stifling.” If the cocoons are not sold as soon as gathered, the chrysalides should be killed without delay unless they are to be reserved for reproduction; otherwise the moths may pierce the cocoons, rendering them unfit for reeling. Cocoons in which the chrysalides are still alive are usually termed ‘‘ green” cocoons. The chrysalides are usually killed either by heat or suffocation. The - killing of the chrysalis is an important operation and one requiring care and judgment. If some are left alive, the moths will issue, thus rendering the cocoon of little value and staining the adjoining cocoons. 165 27 If the hot air of a stove is employed, the cocoons may be placed in the oven with the doors open, but great care must be used to see that the silk does not become scorched. If steam is employed, the cocoons may be placed in a colander over a vessel of boiling water. Do not allow the water to boil too hard, as only the steam must reach the cocoons. A, method of choking cocoons adopted by Mr. T. A. Keleher, of this Department, and now largely followed, consists of placing the cocoons in an air-tight box of about 24 cubic feet capacity and with them a saucer containing about half an ounce of bisulphid of carbon and leaving over night. It is best to open one or two of the cocoons to find if the chrysalides are dead; if not, the operation must be repeated. Care should be exercised that no fire of any kind be brought into the vicinity during this operation, as the bisulphid of carbon is very inflammable. Cocoons to be dried should never be placed in layers of more than 4 inches depth. The shelf or tray that contains them should be per- forated in order to allow air to circulate. They may be placed in the sun daily and dried in much the same manner that fruit is dried on a farm, carrying within doors at night or when rain threatens. At the Department a large fruit evaporator is being used with great success to dry cocoons quickly. Only a slow fire is m&intained, and the heat, is never allowed to rise very high. When a cocoon is thoroughly dried, the chrysalis can be crumbled between the fingers into a powder. The thread of a cocoon is continuous with that of the web and diminishes in diameter within. Its length varies from 1,200 yards to 1,600 yards. Different races, sexes, and conditions of rearing often produce notable differences in weight of cocoons. Thus the weight may vary from 155 to 320 cocoons to the pound (340 to 700 to the kilo- gram) for ‘‘green” or newly spun cocoons or 465 to 960 for dried ones. =e eee S Eaa) Dee “i Rhy re siir. ots) Cole, veg oetinve. Gone Dee a - a2 sand 4 ke 2 aE Ba ; a +h PELTON MeL y Ettore mT : ‘fae Md HOT ey ts dour hg es EM Reps’ ne Whe AL ee Die Pa ed a aa, pee oe I eae ta ee ee ; i he ghee 1, olay’ sire SOR att tl ioe ie nee a Wa SP eid eae stars wianerad wal. a i Bea Waa See PED or fang TT .. 2. Spear re : ae eo BP it pe Ry er tu Ror ngs is : nce fie te a tant? Pre ee ee ee OMIM HKrwWNrF OD WIMMD NK | Nr WWwWWWWwWNNnNNN HWW ND WD WD WH RPwWNrF OO OM aI1D ok OO NW. © ILLUSTRATIONS. . Method of hoisting tent over orange tree..............-.----------- . Tent carried over tree by the falling of pulleys ------.-........--..- huleii ith pombe 1pm TunNeali Ons sos al. eee ele oe sunemavine tent by horse powersiis2<2592 0s.2 55-20 h. cee. 2-0 ee . Series of tents for continuous operations ...........-.-.--.--------- . Tents, tackle, and chemicals loaded for transportation --....-.-.--.--- . Gasoline-power spraying outfit with four lines of hose in operation - . . Hand-power spraying outfit with two lines of hose in operation -..-- pene peale (Matera QlONera) i> fo Ss oo. SSO Pg . Purple scale ( Mytilaspis citricola), stages of female -...-...---------- oc Durie Seale, staves of male (ac 25: ao te ee eke eek Geen ake ane . Purge scale, formation of scale‘ covering <. 2.22. sn2.2-02.-.0- Sheces . Florida red scale (Aspidiotus ficus).......-...-------2------+------- . California red scale}(Aspidiotus auraniit).-..5.22-22-.22-22--225.222 - Oleander seale\(-Aspidiotus hederte).....52-. 5.22 0c2e ce eee e fee eke Sts ncale (Por aaa Nerganier) ooo Ae. Soe. sate Ree Ste ob e-ee- ~ wommee Chignaspis (Chonasns Ciirt) 102.2 25522 snesce ee secant se . Black scale (Lecanium olex): Group of scales...........------------ P BMmcmocue, Newly natcneu larya. 2. .5.c5= 2 oe. ces teccs cae cdscen Black scale mim ale Serleses se ona eA ease Sore takes ce as Sra . Imported ladybird ( Rhizobius ventralis), enemy of black scale..-..--- . Imported chalcidid (Scutellista cyanea) parasite of black scale..-.--.-- Pepi Seale | LecaniiN RESMEMUWIHL)’ 2.0.52 < = bed neon g sas cectanee ems . Hemispherical scale (Lecanium hemisphxricum) ...-.---------------- . Florida wax scale ( Ceroplastes floridensis).....-....----------------- . Barnacle scale (Ceroplastes cirripediformis) .......------------------- . Fluted scale (Icerya purchasi), female series.............----------- Pellutediscal es: male: serlesic2)) se a2 so neidos oan cose eee cc ct.c sce aa . Australian ladybird (Novius cardinalis), enemy of the fluted scale. --- Sey ATL Pes EOD IEEE | ooo ei) Co nisipr die a's em nin <= Swe wisn wa Sie . White fly (Aleyrodes citri), various figures................---------- a Whitediy, winged male amd female.:% 202. .2..2.55.02e2 52425, oeee . The rust or silver mite (Phytoptus oleivorus) .......-....------------ . Six-spotted mite of the orange (Tetranychus sexmaculatus) .......--+- 172 A 0 rh #2 sit: anaes : Byigeasle of Sa , labia eile lan tel Spey Sh ei eregueien? att bolal shinee ng Sidhe iden Je > a ii citer bo taal? tet Aw olhie UreeN srengs at ra a rhage abet te sen howd Whe Mee gabe 1a

mie SA tie hitbny d cittnn he tel + Sem ke dA TSE EL Arete Se hay “ Fier ea ; rele ree a ote shed Tey vectors, Hereby eens by fir ictal fabri ‘eit ed: WAR ‘4 Ke (ReaD ee T ey tshirt iia, oF ntfs inebinigge el” 4 PRD Reveal rte, A Acta} 9 istene St ; ee 5 rots sip kg meek OAR TRE AY See re ee ais icicles gt 8E. ane bate oop om cae. URRY RAD Mpa): fe Gee Rae shin? ae" Re els tee Testes Pamala ash ea ae 4 =f RR ee rey mares yf ala: vi Kameenadt, eR : k ites Sheenat , (aovioneg eel) Be bein: oS ee errr ere ee ey te ae lcm band, | a , ....Hlpo8 eeutrerdt to veces J etoribrod sunt) frihehal ellen ome Scat ae is Laisa th acs Bere Re ee oe ~ So sero AA> gut inal, 2 Tes Pee er wees (ay sshrmgslh) seit ati We” tos > stink ona eds op as hnstlee tes snes OLR Reina fengectiee eh Hh E, ) or Sh enw Se doin wo & ake’ vhs Sop cl CRIS ID os ye atins tart tia 20 Jogey od ee te weet, sess (oMloloonns aaingnonis? ) wine sf id Stat bane, SCALE INSECTS AND MITES ON CITRUS TREES." INTRODUCTION. The scale insects, or bark-lice, are the most important insect enemies of citrus, as they are also of most other subtropical plants. They are, as a rule, small and inconspicuous singly, but they multiply so rapidly that very soon an entire plant becomes infested—trunk, limbs, leaves, and fruit. The attacked tree is rarely killed outright, but its growth may be almost completely checked and its fruit rendered valueless. Next in importance to the scale insects are the mite enemies of the orange and lemon, as represented by the mite which causes the rusting of the orange in Florida and the silvering of the lemon in California, and also the leaf mite, known from its coloring as the six-spotted mite of the orange. These mites occur with the scale insects, are subject to similar remedies, and may properly be considered in the same ~ connection. Of very great importance to the Florida grower of citrus fruits is the so-called white fly, the latter not being a scale insect in the ordi- nary acceptation, but in the essential features of life history and habits coming in the same category, and hence properly considered with the true scale insects. There are many insect enemies of citrus plants other than the scale insects and mites, but, for this country, at least, these others, in the main, have no great economic importance, or are only very occasionally abundant enough to be especially destructive. Occurring about the orange and other citrus trees will also be seen many other insects which play a beneficial rdle, preying upon or para- sitizing the scale insects living on these trees. It is very important to make the acquaintance of these beneficial species, more particularly to avoid, whenever possible, killing them in the warfare waged against the injurious ones. «No one can discuss the insect enemies of citrus plants without acknowledging indebtedness to the very comprehensive and valuable work, now long out of print, prepared by the late H. G. Hubbard and published by this Department in 1885, under the title ‘‘ Insects affecting the orange.’’ The practical side of Mr. Hubbard’s work is especially to be remembered, and particularly that he devised kerosene-soap emulsion, which, with allied washes, has for many years been the leading means of controlling scale insects. 59729—Bull. 172—08——2 5 6 INFLUENCE OF CULTIVATION, PRUNING, AND CLIMATE. With the orange and lemon as with other plants, negligent cultiva- tion and improper care, or any unfavorable conditions of climate which weaken the vitality and vigor of the tree, encourage the pres- ence and multiplication of the insect enemies. On the other hand, vigor of growth is repellent to insect attack; and it will be almost invariably found that the unhealthy tree is the one first severely infested with scale insects or mites. This does not mean that vigor- ous healthy trees will not be attacked, but such trees are less apt to be completely invaded. Asa means of protection against scale insects, a proper system of cultivation and pruning is therefore highly important. The value of pruning as a means of preventing scale-insect injury can not be too strongly urged. Scale insects thrive best where they are protected from direct sunlight and free movement of the air, hence trees of dense growth, unpruned, are almost certain to have their cen- ters, at least, scaly. A well-pruned tree, in which free access is given to light and air, is much less apt to be badly attacked than a thick- headed tree, the interior of which is entirely shaded, thus furnishing the conditions most favorable for the well-being of scale insects. The abundance or scarcity of scale-insect pests is very much influ- enced by climatic conditions. A moderate amount of moisture and warmth are the favoring conditions. On the other hand, a very dry climate accompanied during the summer season by excessive heat, will frequently destroy most scale pests, as will also a high degree of humidity with high temperature such as characterizes many areas within the Tropics, the latter condition developing fungous diseases which often keep most scale species well nigh exterminated. The favoring intermediate climate is illustrated by the citrus districts of Florida, Jamaica, and the West Indies, where scale enemies are more troublesome than they are in the drier climate of California. On the Pacific coast, also, the moister ocean districts are worse infested than the drier regions farther inland with greater elevation. Under the - latter conditions the black scale, for example, has been almost entirely exterminated by a temperature holding for several days above a hundred degrees, and similar results have been noted with other species. PERIODICITY IN SCALE INSECTS. With most insects injurious to cultivated plants a periodicity is noted in their occurrence in injurious numbers. In the case of sub- tropical species, like the scale insects affecting citrus plants, this periodicity is not so marked as it is with insects in temperate latitudes. That there may be more or less well-defined periods of destructive abundance separated by periods of comparative scarcity is illustrated 172 7 by the noted epidemic of scale infection referred to by Hubbard as prevailing throughout the entire orange, lemon, and olive districts along the shores of the Mediterranean from Italy to Spain during the first decade of the present century, which later subsided very largely of itself, efficient remedies at that date being practically unknown. In this country, scale infestation varies considerably from year to year. The fluted scale, in California, increased enormously during the first ten or fifteen years and threatened the very existence of the citrus orchards. Thanks, however, to the Australian ladybird, and, doubtless also to many native predaceous and parasitic insects, it is no longer feared in California. The long scale in Florida, also, was much more injurious in the first years of its activity than it has been since. In 1896 the black scale was very abundant and destructive in the orange districts about Riverside, Cal. Partly owing to adverse climatic con- ditions and partly to natural enemies, this insect has almost disappeared from this district, which is now one of the least affected by scale insects. These facts are cited to give the citrus grower whatever encourage- ment they may offer, but not with the idea of belittling the need of remedial operations. NATURE OF THE INJURY OCCASIONED BY SCALE INSECTS. The damage occasioned by scale insects is of several kinds. The first and principal injury is the extraction of the juices of the plant, the scale insect in its relation to its food plant being a mere pumping machine, which is continually absorbing the sap from its host. While the amount extracted by a single insect is very small, when multiplied by millions it greatly weakens the plant. With some species the excess is thrown off in the form of so-called ‘‘ honeydew,” which accu- mulates in drops and spreads out over the bark or leaf as a sticky liquid. This liquid attracts ants, which very often gives rise to the erroneous belief that the ants are depredating on the plant. Another form of injury results from the honeydew excretion, which not only prevents normal respiration, but develops a black fungus covering the leaves, twigs, and fruit, and still further stifling the plant and reducing the marketable value of its products. Associated with the damage due to the absorption of the juices of the plant: by the scale insect is a diseased condition, particularly to be noted in the limbs, caused by the irritation excited by the beaks or by. the injection of some poisonous liquid. The extreme injury by scale insects arises from the further fact that they are active the year round in climates where citrus trees can be grown. Their most rapid breeding period is from May to August. but continues through October and November. In the winter or rainy season they are more dormant and breeding is at a much lessened rate. 172 8 4 \ THE NATURAL ENEMIES OF THE CITRUS SCALE INSECTS. The natural predaceous enemies of scale insects of greatest impor- tance are various species of ladybirds, as illustrated by the Australian ladybirds (figs. 21 and 29) imported to control the fluted and black — scales, and a great many native species, which are very effective agents in the control of these and other scale pests. The work of ladybirds is especially important against the young of the armored scale and against the softer and freely moving scale insects which secrete no protective covering. Whenever, therefore, ladybirds of any species are found to be abundant on scale-covered trees, they may be safely recognized as friends and working in the interest of the grower. If they are very abundant, it may even be unwise to fumigate or spray. The black scale has been completely controlled on certain ranches in California by its imported ladybird enemy, and this control has been brought about by the entire cessation of all insecticide operations. Most of our ladybirds, however, will probably stand a spraying with- out being killed, and, as a ile, it is hardly worth while to take the risk of fae while waiting for tem to do their work. The experience, however, on the Cooper ranch and in other localities in California has certainly demonstrated the advantage of giving natural enemies a fair chance. The other important class of enemies of scale insects are the hymen- opterous parasites. The recognition of these is not so easy, but if scales are found pierced with minute round holes, it is a safe indication that they have been parasitized, and that the parasites have escaped and are multiplying in the younger scale insects on the trees, and here again if the parasitism is found to be general, it may be inadvisable to spray or fumigate. The other natural enemies of scale insects are not so ‘auriaeh as those mentioned; still they are of service, and should be recognized. These include ‘ie larvee of the eer flies (Chrysopa spp.), which feed on the young of both the armored and the unarmored scales. There are also a few dipterous, or fly, parasites of scale insects, and the larve of several species of Lepidoptera are carnivorous and feed on the larger species of scale insects, such as the Lecaniums and wax scales. A most desirable outcome would be to secure a complete and prac- tical control of scale insects by their natural enemies; but, so far, this has been fully accomplished in the case of the fluted scale only. Very encouraging results have been secured, however, with other parasites, and the introduction of these is being actively prosecuted. Neverthe- less, spraying and fumigation must be relied upon for some time to come, or at least until the natural enemies have been more fully studied and better means of successfully colonizing them devised. . Climatic conditions also affect the activity of these enemies to such an extent that the same results may not be counted on in different localities. 172 a aS 9 In considering the agency of control afforded by the natural enemies the fact must not be lost sight of that these are dependent on the scale insects for their existence, and that, therefore, a fairly complete exter- mination of the host insects means a like extermination of its enemies. There is, therefore, a natural alternation or periodicity in the abundance of the scale insect and its parasites. A more even balance may be main- tained to a certain extent by artificial introduction of the parasitic insect the moment the scale has begun to be abundant, in this manner assisting the early multiplication of the natural enemy. This is now the practice with the fluted scale in California, South Africa, and Portugal. To succeed in such efforts, it is necessary to have an efficient parasite or predaceous insect, and also regular breeding places where these may be secured when wanted. These conditions may be naturally supplied when a whole district, such as California, is under constant observation and the localities where the parasite and scale are occurring together are known, so that from such points the ladybirds or other enemies may be collected and shipped to the districts needing them. THE DIRECT MEANS OF CONTROLLING CITRUS SCALE INSECTS. Scale insect enemies of citrus trees are directly controlled in two ways: (1) By spraying the infested plants with some liquid insecticide, (2) by subjecting them to the fumes of hydrocyanic-acid gas, com- monly designated as ‘‘ gassing.” Each of these methods of control has its place. THE GAS TREATMENT. The gassing method (figs. 1-6) is undoubtedly the most effective means known of destroying scale insects. It has been in general use Fig. 1.—Method of hoisting tent over orange tree. in California for fifteen years, and to a less extent elsewhere on citrus trees, and the methods are now thoroughly perfected and highly satis- 172 10 factory. Gassing should undoubtedly be employed wherever the expense of the treatment, which is the one objection to it, is not an . object as measured by the value of the crop protected. For most Fic. 2.—Tent carried over tree by the falling of pulleys. species of scale insects, one good gassing is worth as much as two or three sprayings, and, when done at the right season and properly, it very frequently will almost, if not quite, exterminate the scale insects from the treated trees, giving them comparative immunity Fie. 3.—Tent in position for fumigation. often for two or more years. The use of hydrocyanic-acid gas is, therefore, strongly urged wherever the conditions warrant it. Gassing is especially desirable for trees: that have a dense habit of growth, such as the orange, which develops a large, thick head, the spraying 172 ~, i of which thoroughly and completely is almost impossible, especially after the trees have attained any size. Furthermore, with gas there is no danger of spotting the fruit as may happen with improper spraying. (4 \\X “4, i we —— + — — — Fie. 4.—Remoying tent by horse power. The more straggling growth of the lemon makes gassing less necessary, notably where the open system of pruning is adopted. Successful as gassing is, it is not effective in the same degree against all the scale insect enemies of citrus plants. It is especially valuable te F J oO ‘ 3 Utz AM lll"\\WS* Fig. 5.—Series of tents for continuous operations, against the black scale and the red scale of California, but with such of the armored scales as are oviparous, or deposit beneath the old scales eggs which undergo a certain amount of incubation before hatch- ing, gassing is not always effective. Under such circumstances the 172 ; . 12 eggs may not be killed, rendering it necessary to make an additional treatment after a sufficient period has elapsed to allow all the eggs to hatch and the young to escape. The black scale is especially adapted to control by gassing on account of its being, in the main, single-brooded. Applied late in October or early in November after all the young scales have hatched, badly infested orchards have been completely cleaned by a single treatment. Gassing in midsummer for this insect will be ineffective, because a large percentage of the old females at this period cover and protect unhatched eggs. Gassing consists in inclosing a tree at night with a tent and filling the latter with the poisonous fumes generated by treating refined potassium cyanide (98 per cent strength) with commercial sulphuric Fie. 6.—Tents, tackle, and chemicals loaded for transportation. acid (66 per cent) and water. The treatment should continue from thirty to forty minutes, the longer time being preferable. The work is done at night to avoid the scalding which follows day applications, at least in bright sunlight. The proportions of the chemicals as now employed in California are considerably in excess of the amounts recommended a few years since. The gas treatment was first chiefly used against the black scale, and at a season of the year when these scales were all ina young stage and easily killed. The effort is now made not only to kill the black scale, but also the red scale, and to do more effective work with both than formeriy. ‘The proportion of chemicals commonly employed in Los Angeles, Orange, and some other counties in southern California are indicated in the following table, published by, the horticultural com- missioners of Riverside County, Cal.: 172 ss a 13 Amounts of chemicals ordinarily used in gassing. weight of | Rinmeter | aio, | G™pnigs | Suaba cas ; foliage. per cent). | per cent). Feet. Feet. Ounces. Ounces. Ounces. 6 4 2 1 1 8 6 3 li 1} 10 8 5 21 92 12 14 1 5 Bi 16 16 17 8 9 20 16-20 22 10 12 20-24 18-22 30 i 14 16 24-30 20-28 34 16 18 30-36 25-30 52 24 28 The amounts here recommended are thoroughly effective for the black scale at the proper season, and generally effective also for the California red scale and other armored scales. Where the treatment is designed to be absolutely one of extermination, and the expense is not considered, from one-third to one-half more of cyanide and acid .is employed, as indicated in the table following, furnished by Mr. Felix G. Havens, of Riverside, Cal. The greater expense entailed by this larger quantity of chemicals is offset by the more effective results and the longer intervals between treatments: Excessive amounts used for extermination. @ Diameter Sulphuric Time to r Height - : CyanideC.P.| leave of tree. through foli Water. aoe p a (98 per cent).| tent on aay; tree, Feet. Feet. Ounces. Ounces. Ounces. Minutes. 6 3to 4 3 1} }to 1 20 8 5to 6 6 23 2 30 10 7 to 10 15 5to 6 4 to 5 35 12 9 to 12 20 to 30 7to 9 5ito 72 40 » 14 12 to 14 30 to 35 9 to 12 8 to10 40 16 12 to 15 35 to 40 12 to 14 10 to 12 40 18 14 to 16 45 to 55 15 to 18 12 to 15 40 to 50 20 16 to 18 60 to 70 20 to 22 16 to 20 45 to 50 22 16 to 18 70to 75 22 to 25 20 50 24 18 to 20 75 to 80 25 to 30 22 to 26 50 27 20 to 24 85 to 100 30 to 36 28 to 32 60 30 20 to 28 100 to 110 36 to 44 32 to 38 60 aA fumigation of the orangery of the Department of Agriculture demonstrated that half an ounce of cyanide to the hundred cubic feet kills the eggs, even of the black, purple, and other scales. The results are scarcely comparable to the proportions recommended in the tables on this page, for the reason that in these tables the amount of cyanide is greatly lessened with larger trees, and further- more, that the orangery probably retained the gas more effectually than would be the case with cloth tents. Nevertheless, it is interesting to know that a comparatively inconsiderable strength of cyanide, when applied under the best conditions, will prove thoroughly effective against the eggs as well as the insects. ; 59729—Bull. 172—08——3 14 For small trees ordinary earthenware vessels may be used to generate the gas. For large trees requiring heavy doses tall wooden pails have proved more practicable, two generators being employed for the very largest trees. It is important that the water be putin the vessel first, and then the acid, and lastly the cyanide. If the water and cyanide are put in the vessel first and the acid poured in afterwards there is danger of an explosion, which will scatter the acid and burn the tents and the operator. In the spring, when the trees are tender with new growth, and in early fall, when the oranges are nearly grown and the skins are liable to be easily marred, and also with young trees, it is advisable to add one-third more water than ordinarily used, or use the cyanide in larger lumps. ‘This causes the gas to generate more slowly and with less heat, and if the tents are left over the trees a third longer the effectiveness of the treatment will not be lessened. The extremely dangerous nature of the gas must be constantly borne in mind and the greatest caution should be taken to avoid inhaling it. The person handling the chemicals should always have an attendant with a lantern, to hold up the tent and enable the cyanide to be quickly dropped into the generator and to facilitate the prompt exit of the operator. As with spraying, the gassing is often done (and this is very desira- ble also) by individuals or companies who make a regular business of it, charging a fixed rate per tree, depending on size—from 10 cents to a dollar or more. Much of this work is also done under the direct supervision of the county horticultural commissioners, which gives a greater assurance of efficiency. Practically, the only tent now used is the so-called ‘‘sheet tent,” which is drawn up over the tree by means of pulleys (figs. 1-3). For very large trees, averaging 30 feet in height, it is sometimes necessary to employ two sheets to effect a complete covering. Some of the tents employed are of great size, the one illustrated in the figures, from photographs secured by Mr. Havens, having a diam- eter of 76 feet. As described by Mr. Havens, it is constructed of a central piece 50 feet square, of 10-ounce army duck. Four triangular sidepieces, or flaps, of 8-ounce duck, 10 feet wide in the middle, are strongly sewed to each side of the central sheet, forming an octagonal sheet 70 feet in diameter. About the whole sheet is then sewed a strip of 6-ounce duck, 1 yard wide. The tent is handled by means of ropes and pulleys. A 13-inch manila rope is sewed about near the edge of the central piece in an octagonal pattern. Rings are attached to this rope at each of the eight corners thus formed, and also on opposite sides of the outer edge. To these rings the pulley ropes are fastened and the tent is elevated. over the tree and handled as indicated in the plates. The treatment is made altogether at night, although it would be 172 15 possible to treat trees also on a very dark or cloudy day. In Cali- fornia, however, at the time the gas treatment is made, such days are infrequent. About 50 trees of the largest size, 30 feet high or there- abouts, can be treated ina night with an equipment of twelve or fifteen tents (fig. 5). By the time the last tent is in place, the fumigation in the first is completed, and it can be taken down and moved forward, and so on with the others; thus the men at work handling the tents are kept continuously employed. Working in the same way with smaller trees, the number which can be treated ina single night is very considerable, it being possible to gas from 300 to 500 trees, averaging 10 feet in height, in eleven or twelve hours, employing 35 to £0 ring tents. SPRAYS FOR CITRUS TREES. It may often happen that gassing is impracticable or that the expense of the treatment is not warranted. This last may be the case where the rancher has not sufficient capital to keep up the heavy Fic. 7.—Gasoline-power spraying outfit with four lines of hose in operation. outlay necessitated by the treatment of young stock which yields no revenue. Gassing is also difficult and less desirable where, as for the lemon in southern California, the low, open-center pruning is adoptted, the trees under this system of pruning often having an expanse of 20 feet, with a height of scarcely more than 6 feet. This open system of pruning and more straggling form of growth, on the other hand, makes the lemon easier to treat with liquid sprays, and under such conditions spraying will probably prove more practicable and profit- able than gassing. Nevertheless, where lemon trees are of a form and size to admit of it, and the crop warrants the expense, gassing is always to be recommended. The expense of spraying is not heavy, compared with that of gassing. In most of the citrus districts of California where spraying is practiced to any extent there are individuals who make a business of treating orchards at a charge of a cent a gallon for the liquid applied, or about 172 16 double that price when they furnish as well as apply the insecticide. This work is now commonly done with a power apparatus (fig. 7),¢and usually in a fairly satisfactory manner. The difficulty in depending on the public sprayer is that it is very often not available when much needed. Fora large ranch the possession of a power spraying outfit will probably prove economical in the long run, and anyone contem- plating securing one is referred to the general article on such machines, by Dr. L. O. Howard, in the Yearbook of this Department for 1896. For the small rancher, having from 10 to 30 acres of orchard, it is not necessary to go to the expense of a steam or a gasoline spraying apparatus. There are a great many excellent force pumps on the market which may be easily equipped with suitable hose and nozzles, and which will do the work of spraying very satisfactorily. A hand force pump with suitable connections, which may be equipped for 4. , : UMWye \\) j Lo; 74 : Wr Yd fn XX Zinya\' YA i\ awl YN 2a SES alle ae ae) Fic. 8.—Hand-power spraying outfit with two lines of hose in operation. work at a cost of from $25 to $30, will meet all requirements. The pump for such an outfit should be capable of easily producing a pres- sure of 100 pounds, which will supply four cyclone nozzles attached to two lines of hose. With such an apparatus (fig. 8), the writer was able to spray easily 50 gallons an hour, or 500 gallons a day, working with three men, and this covers also the time lost in mixing the insec- ticide and refilling. The cost of applying the same amount of liquid by a contract sprayer would probably be a little less, but under per- sonal supervision, the work will undoubtedly be better done and with less waste of material, and, of more importance still, at the time when most needed and when the greatest advantage will result. Trees under seven years old will probably require from half a gallon to a gallon of spray per tree. Foran orchard of 10 acres, or about 860 trees, the cost of spraying would be about $8 for the spray and «From photograph furnished by F. Kahles. 172 17 as much more for the labor. In other words, spraying with the insecticides commonly employed, such as ‘‘ distillate,” kerosene emul- sion, and resin wash, may be safely estimated to cost about 2 cents a gallon for the amount of liquid used, or not exceeding 2 cents per individual tree under seven years of age. On the other hand, gassing trees seven years old will cost from 12 to 15 cents per tree, or the equivalent of from five to sevensprayings. The advantage, therefore, of spraying, for the small owner, and for trees especially suited by form of growth or pruning to such treatment, is evident. The oily washes are by far the best for use on citrus trees against scale insects. The attempt has been made in various places to substi- tute lve washes for the old standard kerosene washes, but the effect has, as arule, been disastrous. Lye strong enough to kill scale insects applied to a tree, as demonstrated by Hubbard fifteen years ago, is very destructive to the tender growth of the tree, and the damage from the wash is often greater than that occasioned by the insects themselves. In California, the kerosene and resin washes formerly used have now given place, to a considerable extent, to a modification of kerosene emulsion known as ‘‘ distillate.” As now employed, the washes in the order of their popularity are: (1) Distillate; (2) resin wash; (3) kero- sene emulsion. The probability is that distillate will ultimately sup- plant the other two on account of its equal, if not greater, efficiency and smaller cost. Distillate—This wash was originated by Mr. F. Kahles, and has found very general use in the Santa Barbara region, and also in the lemon districts adjacent to San Diego, as well as in other citrus dis- tricts in California. It is substantially an emulsion of crude kerosene, made in the same way as kerosene emulsion, except that a greater amount of soap and only half as much oil are used. Its cheapness results from the latter fact. In spite of this lessening of oil it seems to be, if anything, stronger than kerosene emulsion. It is termed distillate spray, because the oil used is a crude distillate of the heavy California petroleum, or the crude oil minus the lighter oils. The emulsion or ‘‘cream,” as it is generally known, is prepared as follows: Five gallons, ‘‘28° gravity,” untreated distillate; 5 gallons water, boiling; 15 pounds whale-oil soap. The soap is dissolved in the hot water, the distillate added, and the whole thoroughly emulsi- fied by means of a power pump until a rather heavy, yellowish, creamy emulsion is produced. For use on lemon trees it is diluted with 12 parts of water, and with 15 parts of water for the orange. The ** distillate cream” is prepared and sold by oil companies and private individuals at from 10 to 12 cents a gallon, making the dilute mixture, as applied to the trees, cost in the neighborhood of a cent a gallon, 172 18 Kerosene emulsion, made by the same companies, costs from 12 to 15 cents a gallon. In using these oil emulsions it is advisable to first break the water by the addition of a little lye, one-four th pound being ample for 50 gallons of water. Kerosene emulsion.—This wash, made according to the old formula (kerosene, 2 gallons; whale-oii soap, one-half pound; water, 1 gallon), is prepared in the same way as the distillate and used at the same strength. It does no harm to use double the quantity of soap indi- cated, securing in this manner a rather more stable emulsion. This emulsion, while perhaps somewhat less efficient than the distillate emulsion, is always available where the latter may not be in reach. It may be prepared on a small scale with an ordinary hand pump, but is best prepared in large quantities with a gasoline or steam-power pump to mix and emulsify it after the soap has been dissolved in the water by boiling. The resin wash.—This wash is especially valuable against the Cali- fornia red scale. It may also be used against any other scale insect, including the black scale and the various armored scales affecting citrus trees. The wash is made as follows: Resin, 20 pounds; caustic soda (78 per cent), 5 pounds; fish oil, 24 pints; water to make 100 gallons. Ordinary commercial resin is used and the caustic soda is that put up for soap establishments in 200-pound drums. Smaller quantities may be obtained at soap factories, or the granulated caustic soda may be used, 34 pounds of the latter being the equivalent of 5 pounds of the former. Place these substances with the oil in a kettle with water to cover them to a depth of 3 or 4 inches. Boil about two hours, mak- ing occasional additions of water, or until the compound resembles very strong black coffee. Dilute to three times the final bulk with hot water, or with cold water added slowly over the fire, making a stock mixture to be diluted to the full extent as used. When sprayed the’ mixture should be perfectly fluid, and should any sediment appear the stock mixture should be reheated; in fact, the wash is preferably applied hot. This wash is more difficult to prepare than the emulsions referred to above, and is therefore much less employed. CITRUS SCALE INSECTS: CLASSIFICATION AND CHARACTERISTICS. For the purpose of this paper a very simple classification of citrus scale insects may be adopted, namely: (1) The armored scales, or those forming a protective covering scale and losing their limbs and the power of changing their situation as soon as they settle down to feed as newly hidtched ye vee; (2) those species which secrete no covering shell or scale and retain their limbs and the power of moving about during most of their lives. The species belonging to both groups are commonly called scale insects, although the term might seem properly to apply only to the 172 ‘ 19 first group; nevertheless, the old insects in the second group, when they become hardened, and, in fact, the younger stages also, greatly resemble scales; hence, the name may properly apply to them as well. These insects all belong to the family Coccide of the order Hemip- tera, or true bugs, being allied to plant-lice and other suctorial insects of this order. In the larval stage the scale insects, except in point of size, closely resemble the larvee of the higher forms of Hemiptera, and are active and can run about on plants or may be carried from one plant to another by the wind, or by birds or other insects to which they may attach themselves. In the case of the armored scales, as soon as the young have under- gone their first molt they appear as mere sacks provided with long sucking beaks, but without legs or eyes, and are very much degraded structurally from the larval condition. The unarmored scales, while retaining their limbs throughout life, are not apt to move very much after they have once settled and begun to feed, except in the case of one or two species. The power of locomotion, however, is retained, and in the case of the fluted scale and mealy bug is often actively brought into play; the Lecaniums and wax scales are apt to migrate late in their lives from the leaves to the twigs. The female insects of both groups remain on the plants and never advance to a winged stage. The males of both groups, however, while paralleling the development of the females in the early stages, in the later stages transform to pupe, and eventually emerge as minute, two-winged gnats. The life of the winged male is very short, and its sole function is to fertilize the eggs of the female. It is a very delicate creature, having no mouth parts, but in place of them a second pair of prominent eyes. GROUP 1.—THE ARMORED SCALES. The majority of the important scale-insect enemies of the orange belong to the group known as armored scales because the insects begin to excrete as soon as they thrust their beaks into the tissues of the plant a waxy covering which protects the growing insect and forms a definite scale-like shield entirely independent of the insect itself. This group includes the long scale, purple scale, the red scale of California and the red scale of Florida (an entirely distinct insect), the oleander scale, the chaff scale, and other less important species. In general habits these armored scales are very similar. The eggs, which are developed in enormous numbers, may be extruded under the covering scale of the mother insect and undergo a longer or shorter period of incubation before hatching, or the young may be partly or fully developed within the body of the mother and emerge as active insects, or more properly shake off the egg envelope at the moment of birth, so that certain species appear to yield living young. The young 172 20 of these different species of armored-scale insects very closely resemble each other, and can not be distinguished without careful microscop- ical study. While very minute, the young are yet visible to the naked eye, and during the breeding season may be seen, by sharp inspection, running about on the leaves, twigs, and fruit. In color they are usually light lemon-yellow. They have six well-developed legs, also antenne and eyes, and are highly organized in comparison with the degraded condition soon to be assumed. After finding a suitable sit- uation, often within a few minutes from the time of their emergence, though sometimes not for an hour or two, they settle down, thrust their long slender hair-like beaks into the plant, and immediately begin growth, the first evidence of which is the secretion of waxy filaments from the upper surface of the body, which mat down and form the beginning of the scale covering (fig. 12). This waxy secre- tion continues during the life of the insect, the covering scale being enlarged as the insect increases in size. The females undergo two molts, and the skins thrown off in these molts form a definite part of the scale, being cemented to it closely with the wax. The female insect, after the second molt, soon reaches full size, and when fertil- ized by the male begins to develop her numerous progeny. The preliminary stages of the male scale insect exactly correspond with those of the female. After the first molt, however, the male assumes'a slightly different appearance, being more elongate than the female at this stage. With the second molt the male diverges entirely from the female; the old skin is thrust out from beneath the covering scale, and does not become a part of it, as with the female, so that in the case of the male insect the first-shed skin only is associated with the scale, which never becomes more than one-half the size of that of the female. With this second molt the male insect transforms to a pre- liminary pupal stage, in which the antenne, legs, and wings are par- tially developed. A third molt occurs with the male insect, resulting in the final pupal stage, which exhibits more fully formed legs and wings than the preceding stage and also the so-called terminal style. A fourth and last molt of the male produces the perfect insect, which escapes from beneath the covering scale and can fly about (fig. 11, 2). The periods between the moltings vary with different species and with weather conditions. Most of the species, however, reach full growth in from four to six weeks in summer; development is slower in winter. The female insect, having once thrust her beak into the tissues of the plant as a larva and begun the secretion of a covering scale, never moves from her position; and, in fact, if she be removed by force is never again able to penetrate the bark with her sucking beak, and soon perishes. The opportunity for the local spread of these insects is, therefore, limited absolutely to the larval stage, as in this respect they 172 —— 21 differ from the Lecaniums and mealy bugs, which have the power to move about until nearly the end of their growing period. The number of eggs from a single female varies somewhat with the species, but may be from 100 to 500, the number being less in unfavor- able seasons. The progeny from a single female in a year, if they should all survive, would represent almost inconceivable numbers, running into the billions. It is not to be wondered at, therefore, that plants become thoroughly infested with these insects in a very short time, especially in climates where the breeding is but little checked by the winter season. The waxy covering makes it necessary to use rather strong washes to penetrate the scale. The difficulty increases when the old scale protects a mass of eggs, as is usually the case with the species of Mytilaspis, represented by the long and purple scales; and it is not always possible with the best washes to kill all the eggs of these species, hence the necessity of spraying re- peatedly to destroy the young as they emerge. Remedial operations should be instituted as far as possi- ble when the greatest percentage of the scales are in a young or partly mature condition. The Long Scale. The long scale (Mytilaspis glovert Packard—fig. ?) is supposed to have originated in China, but in common with most of the other species dis- cussed has now a world-wide distri- Fie. 9.—Long scale (Mytilaspis gloveri): Group F { ‘ figure, showing cluster of male and female bution, being represented in practi- _ scaleson fruit of orange—enlarged 7 diameters j i ; iginal). cally every important citrus region. ("8") It made its appearance in Florida about 1838, and soon became a very serious pest in that State and elsewhere in the Gulf region. At its first appearance it was vastly more destructive than later on, parasitic and natural enemies having in later years kept it decidedly in check. At present it is everywhere distributed throughout Florida and Louisiana, in the orange and lemon groves, and also on wild orange. Strangely enough, it was a long while getting into California. About 1889 or 1890, however, in company with the purple scale and rust mite, it was earried into California on a lot of stock from Florida, but it has not developed as a very serious pest in the Pacific coast region. This insect is characterized by its very elongate form; in other respects it closely resembles Mytilaspis citricola, and also the common oyster-shell scale of the apple and other deciduous fruits. In color it 172 22 is a rather rich reddish, often obscured fy extraneous matter taken from the surface of the leaves or bark. It apparently requires a great deal of moisture to thrive well, and hence is apt to be abundant on oranges or other plants grown in conservatories, and this also accounts, doubtless, for its greater multiplication a injury in Florida than on the Pacific coast. Breeding continues practically throughout the year. According to Hubbard, there are three periods in Florida when the young are espe- cially abundant, marking in a rough way the appearance of the main broods, namely, in March and Aprii, in June and July, and in Septem- ber and October; the fourth, irregular brood, occurring in January or February. The treatment for this scale is the use of the oily washes and fumi- gating with hydrocyanic-acid gas. It is much more easily controlled than the purple scale. The Purple Scale. The original home of the purple scale (Mytilaspis citricola Packard) (figs. 10 to 12) is unknown, but it now occurs practically wherever Fie. 10.—Purple scale (Mytilaspis citricola), showing different stages of female: a, newly hatched larva; 6, same with first waxy secretion; c to f, different stages of growth; g, mature scale; h, same inverted, showing eggs; 7 and j, half-grown and full-grown female insects remoyed from scale—all much enlarged (original). the orange or lemon is grown. It was probably introduced into this country at an early date. It is frequently associated with the long scale, and is one of the most troublesome scale insects affecting the orange and lemon, because it is very difficult to get an application on the trees strong enough to kill all of its eggs with one treatment. For many years the purple scale was limited in this country to Florida and the Gulf region, but some years since it was carried on Florida stock into southern California, where, fortunately, it has not yet become widely distributed. In general color it is a brownish purple, and in shape duplicates the oyster-shell scale of the apple. The life 172 23 history and habits are the same as those of the long scale. The purple scale is not limited to citrus fruits, but occurs also on many other plants. Fig. 11.—Purple scale (Mytilaspis citricola),show- Fic. 12.—Purple scale (Mytilaspis citricola), illus- ing different stages of male: a, fully developed trating the formation of the scale covering’ a, male scale; b,same inverted, showing male newly hatched young, with enlarged antenne at pupa within; c, propupa; d, final pupal stage; leftand leg atright; b, side view of forming scale; e, Mature winged insect; /, foot of same much c,same from above—all greatly enlarged (origi- enlarged—all greatly enlarged (original). nal). Neither the gas treatment nor any of the washes 1s a certain remedy for this scale, except in the immature stages. Occasionally a very strong treatment will kill the eggs, but it is usually necessary to repeat the application once or twice at inter- vals of two or three weeks to effect anything like extermination. The Red Scale of Florida. This is another scale insect (Aspidiotus jicus Ashmead) of world-wide distribution. As an or- ange scale it is not a very serious pest on trees grown out of doors, but on trees grown in con- servatories or under = lass Fig. 13.—Florida red scale (Aspidiotus ficus): a, leaves covered it is very apt to thickly with the male and female scales—natural size; b, newly s i hatched insect with enlargements of antenne and leg; ¢, d, infest the leaves and e, f, different stages in the development of the female insect, fruit. It has a very wide drawn to the sgme scale; g, adult male scale—similarly enlarged (original). . range of food plants and is one of the commonest of scale insects. This and the following species differ from the Mytilaspis scales in being nearly circular in general outline, with the molted skins in the center of the scale instead of at the small end (fig. 13). The color of this scale is a rich reddish 172 24 brown, almost black. The central portion, however, is much lighter, giving the appearance of a dark ring with a light center. The num- ber of generations can not be accurately given, breeding going on throughout the year, but undoubtedly in greenhouses and tropical regions six or seven generations are not unusual, and in subtropical regions five generations may be safely counted. It seems never to have attracted any attention as an enemy in the orange and lemon groves of California, the dry climate evidently not suiting it. The moist climate of Florida and the Gulf region seems more favorable to it. The Red Scale of California. This species (Aspediotus aurantit Maskell) (fig. 14) is entirely distinct _ from the red scale of Florida. Its name comes not from the covering scale, as with the Florida species, but from the fact that the body of the mature female turns a reddish brown and shows through the thin transparent waxy scale. This insect, although for years very common and de- structive in the groves of southern California, and enjoying also a cosmopoli- tan distribution, has, curi- ously enough, never ap- peared in a destructive way elsewhere in this country. Its origin is a matter of A Fie. 14.—California red scale (Aspidiotus aurantit), ilus- 2 trating a group of the female and male scales as they SOMe uncertainty. Itis now occur on an orange leaf—enlarged about 7 diameters widely distributed, and has ak (original) undoubtedly been a scale pest in oriental countries for centuries. It is not limited to citrus plants, but may occur on almost any plant growing in tropical or subtropical regions. It is the most destructive and injurious of all the scale insects affecting the orange in California, being especially troublesome in the districts about Los Angeles. So far no effective parasites or predaceous insects have been found to combat it. It is controlled by the oily washes, and also by the gas treatment. The young are born free, or, in other words, the insect is semi-oviparous, and therefore any wash which will kill the old scale will destroy the young also. This insect has, in California, a rather well-marked variety, known as the yellow scale (Aspidiotus citrinus Coq.). This variety does not differ in any structural feature from the red scale, but the mature insect remains yellowish in color. This variety is attacked by quite a number of parasitic flies, which keep it more or less in check, so that it is not, as a rule, so abundant as the red variety. 172 25 The Oleander Scale. This species (Aspzdiotus hedere Val.) is not distinctively an orange pest. It occurs on a great variety of plants and has a world-wide distribution. It occasionally occurs on the lemon and orange, especially in California, not apparently being so likely to attack this plant in Florida. It is a very delicate scale, with a very thin waxy covering, and yields readily to treatment. It frequently occurs on the oleander, and is commonly known as the oleander scale (fig. 15). The male scales are white and very greatly exceed the females in abundance (much more so than indicated in the accompanying illustration). The : ‘ Fic. 15.—Oleander scale (Aspidiotus hederx), female scales are light buff in color illustrating a group of the female and male with a faint pur ple tin ge, rather scales as they occur on a leaf—enlarged about a P 7 diameters (original), than white, are two or three times the size of the male scales, and rather larger also than the scales of the species already described. The fruit of the lemon and orange is often invaded by the females of this species. The Chaff Scale. With this scale insect (Parlatoria pergandei Comstock) the molted skins are at one end of the scale, as in the case of Mytilaspis, and the scale is oval or nearly circular, as in the case of Aspidiotus. It is very apt to be clustered thickly, often overlap- ping on leaves or twigs and fruit, giving the surface a rough appearance, as though covered with loose chaff (fig. 16). In color the female scale is light straw-yellow, the female insect show- ing through, usually with a greenish tinge. The number of generations and life history correspond very closely with the species already de- Fic. 16.—Chaff scale (Parlatoria pergandei), F illustrating a group of the female and scribed. Asa rule, the chaff scale by male scales as they occur on a-leaf—en- Dae aiee ccna), preference remains on the trunk and branches, covering these portions of the plant densely before going on the leaves and fruit. This fact renders it somewhat less noticeable than the other species, and its presence may, for a time, be overlooked. The chaff scale has been destructive, so far, only in Florida and the Gulf region, having apparently been introduced from the Bermuda 172 26 Islands or some of the West Indies. It is closely allied to certain scale insects occurring in the Old World, and probably came to this country from Europe or Asia. It yields to the same treatments which are advised for the other armored scales. The Orange Chionaspis. This species (Chionaspis citri Comstock) occurs in the orange groves of the Eastern United States, and is .also especially trouble- some in Louisiana. Professor Morgan reports that its presence on the trees causes a bursting of the bark and very ugly wounds, followed in very many cases by the rotting of the trunks of the older trees. The orange Chionaspis (fig. 17) is found also in several of the West Indian islands, Mexico, and in most foreign countries where cit- rus fruits are grown. The male scales are striking objects on ac- count of their white color, and the Fig. 17.—Orange Chionaspis ( Chionaspis citri), il- S - as . lustrating a group of the female and male scales females are readily disting uished as they occur on a leaf—enlarged about 7diam- from the other armored scales of ters (original). any, Spann similar general shape by the dis- tinctly ridged appearance of the waxy portion. The orange Chionaspis is readily controlled by the same treatments advised for the other armored scales. GROUP 2.—THE UNARMORED SCALES. The species to be considered in this group include three Lecaniums, the mealy bug, two wax scales, and the fluted scale. Strictly speaking, the Lecaniums are the only ones which secrete no covering. The mealy bug secretes a waxy or mealy powder, which covers its body, anda similar secretion in less amount is made by the fluted scale. Both of the latter species secrete very abundant quantities of wax for the pro- tection of their eggs. The wax scales cover themselves with copious waxy secretion, which, however, attaches firmly to the body, and can not be considered as a separate covering in the sense of the scale of the armored species. The development of the different species in this group is very similar, in that they all retain the power of locomotion until nearly the end of their lives, and do not suffer the loss of limbs and the marked retrograde development already described in the case of the armored scales. They excrete liberally the honeydew, which is followed by the smut fungus. In this group are included some of the worst scale pests of the orange and lemon, notably the black scale, the fluted scale, and the mealy bug. Not being so firmly attached nor 172 27 so protected by a covering shell or scale, they are as a rule more easily destroyed by fumigation or sprays, and they fall a more ready prey to attacks of predaceous and parasitic insects. All of the species are egg- laying. The Lecaniums and wax scales deposit their eggs in cavities under their bodies, formed by the contraction of the female insects, so that ultimately the mothers become mere shells over vast numbers of eggs and hatching young. The mealy bugs and fluted scale excrete a quantity of cottony fibers, which are stocked with eggs. After a cer- tain amount of incubation, the young hatch and escape from beneath the old parent scales or burrow out of their cottony nests. In trans- formations and general life history, except in the points noted, these scale insects closely duplicate the habits of the armored scales. The Black Scale. This scale insect (Lecanvwm olex Bernard—figs. 18, 19, and 20) is nota- bly an olive pest, but it also attacks citrus fruits, and is quite as destruc- tive to the latter as to the olive. It is an insect of world-wide distri- bution, having been an important enemy of the olive and citrus fruits in the Old World as far back as we have any records. It also affects a great variety of other fruits and plants. It occurs more or less in greenhouses, and has undoubtedly been transported to various parts of the world upon greenhouse Fig. 18.—Black scale (Lecanium olex): Group of plants as well as upon the various scales, showing natural Position and appear- subtropical fruits. In the United Pal to nbgliiae paodoal fh States it is especially destructive only on the Pacific coast, and while it occurs generally in Florida it has never there assumed any great importance as an enemy of the orange or lemon. It not only saps the vitality of the plants by the extraction of their juices, but also abun- dantly secretes honeydew, which results in a badly attacked plant becoming thoroughly coated and blackened with the sooty fungus. The adult insect is dark brown, nearly black, in color. Its characteristic features are the ‘one longitudinal and the two transverse ridges. Very often the portion of the longitudinal ridge between the two transverse ridges is more prominent than elsewhere, giving a resemblance in these ridges toacapital letter H. The general surface of the body of this scale insect is shagreened or roughened, which will distinguish it readily, under a hand lens, from the allied species, even before the ridges have become prominent. Very fortunately for the citrus grower, the development of this insect is slow, and it has but one brood annually. The young, however, appear over a very wide interval of time, and this gives the appearance of more than one brood. 172 28 On reaching full growth, early in the summer, the female insect deposits her eggs beneath her already much-hardened parchment-like Fig. 19.—Black scale (Lecanium olex): a, greatly en- larged drawing of newly hatched larva, viewed from beneath, with enlargements of anal extremity viewed from above—b, showing anal segment extruded, and ¢, same retracted (original). skin, the lower surface of the body gradually contract- ing until there is nothing left but the shell, covering a mass of hundreds of eggs. The eggs will hatch in a compar- atively short time, but, as the females come to maturity at different dates, the young from this species are con- stantly appearing and spread- ing over the infested plants between June and the end of October. The growth, how- ever, is very slow, and even those earliest hatched do not reach maturity until late in autumn, the latest maturing in June and July of the fol- lowing year. While retaining the power of movement practically throughout its development, this scale insect is very little apt to change its position after it is once settled, or, at least, after it is half grown. There is a general migration from leaf to twig, but the scale often develops Fie. 20.—Black scale (Lecaniwm olex), male series: a, fully developed male scale; }, pupa; c, winged adult—natural size indicated by hair lines (original). on the leaf if the latter remains vigorous and supplies it sufficien nourishment. 172 ee 29 In view of the extraordinary abundance of the black scale it is sur- prising that until very recently the male insect had not been discovered, in spite of the most careful search for it. What we know of this stage is due to Dr. B. W. Griffith, of Los Angeles, Cal., who has found the male scales on oleander, orange, lemon, pepper, and ivy leaves between the months of November and April, in Los Angeles County. The accompanying illustrations of this sex (fig. 20) are based on material ‘furnished by Dr. Griffith. The natural enemies of the black scale promise to be very efficient in its general control and warrant special notice. They include both the parasitic flies and various species of lady birds. Fig. 21.—Imported lady- bird enemy of black scale (Rhizobius ventralis): a, mature beetle; b, larva— Fia. 22.—Imported chalcidid parasite of black scale both greatly enlarged (Scutellista cyanea), dorsal and lateral views—greatly (author’s illustration). enlarged (after Howard). The ladybird enemy of special importance is the RAdzobius ventralis, imported by Mr. Koebele. This ladybird (fig. 21) has been colonized in various parts of California, and in districts where the climatic con- ditions proved favorable its work has been most satisfactory, notably on the ranch of Hon. Ellwood Cooper, at Santa Barbara. Hundreds of thousands of these beetles have been distributed in southern Cali- fornia and have accomplished in some localities a very great deal of good in keeping the black scale in check. Away from the moist coast regions, however, it is less effective, and experience has shown that this ladybird can not be completely relied upon to control the black scale. 172 30 A parasite which promises to be most effective in controlling the black scale is the very odd-shaped little chalcidid fly (fig. 22) known as Scutellista cyanea Motsch., first found attacking Lecaniwm coffee in Ceylon. It was later reported by Dr. Berlese as attacking a wax scale ( Ceroplastes rusct) in Italy. Subsequent to its discovery in Italy, vari- ous efforts were made by Dr. Howard, with the assistance of Dr. Ber- lese, to introduce it into Florida and the Gulf districts, particularly as a means of controlling the wax scales. In the meanwhile it was © found with the black scale in Cape Colony by Mr. Loynsbury, who, at Dr. Howard’s suggestion and with his assistance and the cooperation of different persons in California, notably Mr. Craw and Mr. Ehrhorn, succeeded, in 1900, in getting the parasite into California, where it has been installed under conditions which promise a successful intro- duction of the species. During the last three years it has been con- stantly distributed in California and reports of its work are most favorable. In South Africa, as reported by Mr. Lounsbury, the black scale very rarely is abun- dant enough to be considered at all injurious, and this is apparently due to its parasitism by this little insect. If the latter can be in- duced to play the same rdie in California the saving will be second only to that accomplished by the Vedalia. The remedial measures for the black scale are spraying with the oily emulsions and the gas treat- ment. The Soft Scale. This scale insect (Lecaniwm hesperidum .—fig. 23), also known as the turtle-back scale or brown scale, is closely related Fig. 23.—Soft scale (Lecanium hesperidum): Orange to the black scale, but is a much twig showing, chancteitie masing of O softer and more delicate insect It changes in color with age -from a transparent yellow in the young to deepening shades of brown in the adult. The adult scale has a length of 38 or 4 milli- meters, is turtle-shaped, and very much swollen, the body of the mother in the last stages becoming a mere cap filled with young. In the early stages the insect is thin and flat and semitransparent, so 172 31 that it is scarcely noticeable on the surface of the leaf or twig. It is very commonly found on various greenhouse plants, and has been carried to all parts of the world on such material. In climates suitable for the growth of the orange and lemon it occasionally gains a foot- ~ hold on outdoor plants. It has a gregarious habit, and commonly lives in colonies, frequently covering the young limbs and the midribs of the leaves. These colonies are usually not of long duration, being soon attacked and exterminated by parasitic and predaceous enemies, the soft texture of the insect not furnishing much, if any, protection. The transformation and habits are very similar to those of the black scale. It, however, is much more rapid in growth, and, where the climate is favorable, goes through a continuous series of generations, or broods, throughout the season. It readily yields to oily washes or to the gas treatment. The Hemispherical Scale. This scale (Lecanium hemisphericum Targ.—tig. 24) is also distinc- tively a greenhouse pest, and it can hardly be considered as_ especially injurious to citrus trees in orchards. It occurs all over the world, and occa- sionally will multiply to a slight extent on orchard trees. The individuals are about the same size as those of the last two species. In color it ranges from light brown in the young to dark brown, : : ‘ Fic. 24.—Hemispherical scale (Lecaniwm changing to reddish in the old seale. hemisphzxricum): a, characteristic group p D : : . of adult scales on olive—natural size; The adult scale is hemispherical In b, three female scales—considerably en- shape perfectly smooth and shiny, and _larged; ¢,scale lifted from leaf, showing this, with its color, readily distinguishes =" bectuistaraens it from the other two species. The remedies are those used against the black scale. The Florida Wax Scale. This very curious and striking scale insect (Ceroplastes floridensis Comstock) secretes a white waxy covering, arranged in a very regular - geometrical pattern (fig. 25). It was long known from Florida, where it is undoubtedly native, its principal food plant being the gall berry. It has now been carried, however, to other parts of the world, notably some of the adjacent West Indian islands, and also to the Old World. It was imported into California on stock from Florida in 1889, and possibly earlier, but has never gained any foothold on the Pacific coast. This insect often occurs on citrus plants, though rarely in sufficient numbers to be of very great importance. The white color and striking appearance of these scales cause them often to be noted, 172 32 aud very natural fears of damage are excited, but asa rule the natural enemies and other causes result in very few of the young reaching the adult stage. This, as shown by Mr. Hubbard, not only follows the action of parasites, but also is due to the fact that the scale lice as they their hold on the smooth surface of the lemon or orange leaf and fall to the ground and perish. The citrus plants, therefore, are not especially adapted to this insect and very rarely suffer long or seriously from it. Fi. 25.—Florida wax scale (Ceroplas- The Florida wax scale is three-brooded, sepia emesha ts eit development not being very rapid and g gig about 4 diameters (origi extending over three or four months. The ; waxy secretions give an appearance to the young insect of an oval stellate object, the waxy prominences coalescing and disappearing with age. The Barnacle Scale. This insect ( Ceroplastes cirripediformis Comstock—fig. 26), which is closely allied to the last, has been found in two or three localities in Florida, notably at Jacksonville and in Volusia County, on orange and quince, and also on a species of Eupatorium. It is frequently associated on citrus plants with the Florida wax scale. It has since been found on the same and other food plants on some of the West Indian islands and in Louisiana and Cali- fornia. The barnacle scale is much larger than the Florida wax scale, having an average length of 5 milli- meters and a width of 4 millimeters. The waxy cover- ing is a dirty white, mottled with several shades of Bs F grayish or light brown, and the division of the waxy ie. 26—Barnacle excretion into plates is distinct, even to a late age. The paneer iar © development of the insect and secretion of the waxy — Group of scales scale covering is very similar to.that of the last spe- ioe neereneae cies described. The barnacle scale is of very little eco- stages of growth nomic importance, and is mentioned merely because its — [“u/arsed about , Pr. ie 2 diameters presence might arouse suspicions of probable injury. (original). The Fluted Scale. Of all the scale insects attacking citrus plants, this species (Jcerya ~ purchast Maskell—figs. 27 and 28) is perhaps the most notable, not so much from the damage now occasioned by it as from the problems of control which it has brought to the front and the international charac- ter of the work which it has occasioned. 172 become old and gravid can not maintain * Jay HES 33 The facts indicate that Australia is undoubtedly its original home, from whence it was introduced on Australian plants into New Zealand, Cape Town, South Africa, and California at about the same time. The evidence points to its introduction into California about the year 1868 on Acacia latifolia. It is a very hardy insect, will live for some time without food, and thrives on a great number of food plants. In California it spread rather rapidly, and by 1886 had become the most destructive of orange scale pests. The damage occasioned by it was of such a serious character as to threaten the entire citrus industry of the Pacific coast. The nature and habits of this insect made it almost impervious to any insecticide washes, and the orange growers of Cali- fornia were rapidly losing heart. In 1889, however, through the agency of Mr. Albert Koe- bele, an assistant of this office, the natu- ral ladybird enemy of the fluted scale was discovered in Australia and im- ported into Califor- nia. This ladybird, Nowius ( Vedalia) car- dinalis (fig. 29), mul- tiplied prodigiously, and in a very short time practically ex- i terminated the fluted Fie. 27.—Fluted scale (Icerya purchast), female series, illustrating the scale, saved the State development of the female insect from young larva to adult gravid : : stage: a, newly hatched larva; b, second stage; c, third stage; d, of California annual fuil-grown female; e and /, same after secretion of egg sac—(orig- damage amounting inal and after Riley). to hundreds of thousands of dollars, and removed this scale insect from the roll of dreaded injurious species. The beneficial results derived from this ladybird have not been con- fined to California. Through the agency of this Department and in cooperation with the California State authorities, this ladybird has - been sent to South Africa, Egypt, Portugal, and Italy, and in each of these countries its introduction has been followed by similar beneficial results in the control of the fluted scale. While the fluted scale, at the time or soon after its injurious record in California, gained access to several foreign countries, very fortunately Florida and the Gulf districts remained long free from it. 172 34 The first and presumably only introduction of this insect into Florida was an intentional one, though not malicious, and illustrates the risk run in importations of beneficial insects undertaken by persons unfa- miliar with the subject. A nurseryman of Hillsboro County, Fla., hoping to duplicate against the common Florida scale insects the won- derful work of the imported Australian ladybird against the fluted scale in California and, ignorant of the fact that the ladybird in ques- tion did not feed on any of the armored scales which he especially wished to have controlled by it, got one of the county horticultural commissioners of California to ship him a lot of these ladybirds, together with some of the fluted scale as food. The whole lot was liberated on his premises and resulted, naturally enough, in stocking some of his trees very thoroughly with the fluted scale. The infesta- tion coming to his attention, he sent, in June, 1894, specimens to the Division of Entomology and they were promptly determined as the dreaded California scale pest. Fortunately, the nurseryman in question realized the enormity of his offense and took, at Dr. How- ard’s earnest suggestion, immedi- ate and active measures to exter- minate the fluted scale on his premises, ultimately taking out and burning the trees. Jt was hoped that extermination had been effected, but four years series: a, male insect with greater enlargements of base of wing and foot at band c; d, second later (1898) the fluted scale was stage of larva; e, pupa; jf, cocoon—enlarged again received from the same dis- about 7 diameters (re-engraved from Riley). 2 : trict. In view of its quite general spread, as reported, in the immediate region, it seemed improbable that it could be easily exterminated, and the introduction of the Australian ladybird was urgently advised. During the spring and summer of 1899 the ladybird in question was successfully colonized in Florida by Mr. Gossard, with the assistance of Mr. Craw. The fluted scale in Florida evidently does not multiply as rapidly as . it does in California. Furthermore, as shown by Mr. Gossard, it is attacked by a fungous disease which appears suddenly in July and results in the death of from 25 to 70 per cent of the partly grown scales. We may hope that with the aid of this disease, and by means of the prompt introduction of its natural enemy, the fluted scale will never play the réle in Florida which it originally did in California. The habits and transformations of the fluted scale (figs. 27 and 28) closely parallel those of the species of Lecanium already described. 172 35 The general appearance of the insect, however, is strikingly dissimilar, owing to the waxy excretions from the ventral plate of the adult female insect. These are ribbed, or fluted, from whence the insect takes its name, and become the receptacle of a vast number of eggs, a single female being the possible parent of more than a thousand young. The waxy material constituting the egg sac issues from countless pores on the under side of the body, especially along the posterior and lateral edges. As this secretion accumulates the body is lifted, so that ultimately the insect appears to be standing almost on its head, or nearly at right angles to the bark. The eggs are laid in the waxy secretion as it is formed, the waxy ffuted mass often becoming from two to two and one-half times as long as the insect itself. The young are of reddish color, very active, and spread by their own efforts and by the agency of the winds, birds, and other insects. The female insect is, for the most part, a reddish orange, more or less spotted with white or lemon. The early stages of the male are similar to the correspond- ing stages of the female. Be- fore appearing as an adult, the male insect secretes itself in some crack in the bark, or in the ground, and exudes a waxy covering, which forms a sort of cocoon, in which the transfor- Fie. 29. yc arity cardinalis, Australian ladybird ene- my of the fluted scale: a, ladybird larve feeding mations are undergone, firstinto on adult female and egg sac; b, pupa; ¢, adult lady- bird; d, orange twig, showing scale and ladybirds— natural size (author’s illustration). the pupa and then into the adult insect. The winged male (fig. 28) is rather large for a coccid, and has a reddish body with smoky wings. The rate of growth of the fluted scale is comparatively slow, and it does not normally have more than three generations annually. This insect is quite active, the female traveling and moving about very freely nearly up to the time when she finally settles for egg-laying. The male is active up to the time when it settles down to make its cocoon. The fluted scale exudes a great quantity of honeydew, and trees badly attacked by it are covered with the sooty fungus, characteristic of the black scale and the white fly. The remedy for this scale insect is always and conphatiedlley to secure at once its natural and efficient enemy, the Vowius cardinalis. Where this insect can not readily be secured, the scale may be kept in check by 172 36 frequent sprayings with the kerosene or resin washes. Fumigation is comparatively ineffective against it, because the eggs are not destroyed by this treatment. Spraying is, for the same reasoa, effective only when it is repeated sufficiently often to destroy the young as they hatch. The Mealy Bug. The mealy bug (Dactylopius citri Risso) (fig. 30) of the orange and other citrus plants is especially destructive in Florida and the West Indies. It is not of much importance in California. It occurs very commonly in greenhouses, and has been carried to every quarter of the globe. The insect is mealy white in color, the female attaining a length of nearly a quarter of an inch when fully adult. The edge of the body is surrounded by a large number of short waxy filaments. This insect is active in all stages and the eggs are laid in and protected by a cottony or waxy secretion, the female insect as this is developed being gradually forced from the bark, as in the case Fig. 30.—Mealy bug (Dactylopius of the fluted scale. The adult winged male is ae es of ate at fork of light olive brown. é eaf, showing different stages > and cottony excretion cover- This species is somewhat gregarious and Gio oS occurs in masses in the angles of the branches and leaf petioles and about the stem of the fruit. The remedies are the emulsions and oily washes, repeated as often as necessary to reach the young as they hatch. IMPORTANT CITRUS PESTS OTHER THAN SCALE INSECTS. THE WHITE FLY. The white fly (Aleyrodes citri Riley and Howard) of Florida and the Gulf region (figs. 31 and 32) is not a scale insect, but belongs toa closely allied family. In general appearance and habits, however, at least in its economic features, it exactly duplicates the true scale insects. For many years this very interesting insect has been known to infest the orange trees of Florida and Louisiana and also to be a common pest on the orange in greenhouses. It has been found also on a num- ber of plants other than orange, such as viburnum, cape jasmine, and the aquatic oak of the South. These other food plants are of signifi- cance only in indicating that it may be harbored in situations near orchards in which efforts have been made to exterminate it. The first careful description of this insect and general account of its habits was given by Riley and Howard in 1893, and from their article the data following are largely derived. 172 37 The white fly is limited, economically, to the citrus plantings of Florida and the Gulf region. It is widely distributed in greenhouses, as already noted, and has undoubtedly been carried to California on many occasions, but has never gained a foothold out-of-doors. The dry hot season of southern Cali- fornia probably accounts for this, and may prevent its ever becoming troublesome in that region. Itsorigin isunknown. It first came into prominence about 1885, but probably had been present in greater or less numbers for a much longer period, and perhaps is native to Florida. While closely resembling a seale insect in its early stages, the white fly in the adult stage emerges, in both sexes, as a minute white gnat, having four chalky wings of a fine gland- ular texture, from which fact it is frequently called the ‘‘mealy wing.’ eess \0 0,\o E0509 Fie. 31.—White fly (Aleyrodes citri): a, orange leaf, show- ing infestation on under surface—natural size; b, egg; c, same, with young insect emerging; d, larval insect; e, foot of same; f, larval antenne; g, scale-like pupa; h, pupa about to disclose adult insect; i, insect escaping from pupal shell; j, leg of newly emerged insect, not yet straightened and hardened—all figures except a greatlyenlarged (reengraved from Rileyand Howard). > This active adult condition gives the white fly a distinct advantage over scale insects in means of spread. The damage occasioned by it is greatly increased by the secretion, in Fie. 32.—White fly (Aleyrodes citri): a, winged male insect, with enlarged view of terminal segments at b; c, dorsal view of winged female, with enlarge- ments of ovipositor, head, antenna, wing margin, and leg at d, e,f, g, h, i (reduced from Riley and Howard). the larval and pupal stages, of a honeydew similar to that secreted by the true scale in- sects. This is in enormous amount, and the sooty mold which develops in it frequently covers the entire upper sur- face of the leaves and produces very serious effects on the vital- ity of the plant; the fruit does not ripen properly, is deficient in quality and size, and keeps poorly, involving in addition the expense of washing before it can be marketed. The life round of the insect, briefly, is as follows: The winter is passed in the mature larval stage as a thin, elliptical, scale-like object on the under sides of the leaves. 172 Early in the spring the transforma- 38 tion to the pupal stage occurs, this stage differing but slightly from the larval in appearance. The adults begin to appear by the middle of March and continue to emerge through April. The eggs deposited by this brood require about three weeks for development, hatching into larve from the middle of April to the 1st of May. The adults of the second brood begin to emerge by the middle of June and con- tinue to appear until the middle of July. Between the middle of July and the middle of September a third brood is developed, the larve of which, hatching about the last of October, carry the insect through the winter. The number of eggs laid by a single female is in the neighborhood of twenty-five, and they are placed, by preference, upon new leaves, but all of the plant is taken when the multiplication of the insect makes it necessary. The young larva is active, resembling closely the larva of a true scale insect. The life of the adult ranges from ten to twenty days. The most satisfactory remedies for this insect, as demonstrated by Messrs. Swingle and Webber, are the kerosene and resin washes. The treatments may best be made during the winter, between December and March, and again, if necessary, in May, and also in August or early in September. Two or three applications may be made in the winter. The application in August is made if the sooty mold is found to be spreading to the fruit. Since the insect lives on the under sides of the leaves almost exclusively, it is of prime importance that the under surface be thoroughly wetted with the spray, and it is necessary that the tree be opened up by pruning. Fumigation with hydrocyanic- acid gas is also a ready means of destroying this insect. It is undoubt- edly kept more or less in check by parasitic and predaceous enemies, and is subject to attack by several fungous diseases, which may be cf occasional value in preventing its undue multiplication. THE RUST MITE OF THE ORANGE AND THE SILVER MITE OF THE LEMON. This mite (Phytoptus olewvorus Ashmead—fig. 33) is an enemy of both the orange and lemon, affecting these fruits in a somewhat dif- ferent way. For many years this mite was known only in Florida, and its injuries were notable only in the case of the orange. It is probably native to the Florida peninsula, possibly having originally some food plant other than the orange. The lemon and orange groves of California were for a long time entirely free from the attacks of this mite, but about 1889 some car- loads of citrus trees were taken into California from Florida and planted, without careful inspection, in the Rivera and San Diego Bay districts. This shipment of trees brought with it, unfortunately, two or three of the Florida scale insects, and also this rust mite, which has gained a foothold in the important lemon districts about San Diego, 172 ——- 39 and is now one of the worst pests the lemon grower has to deal with. For a number of years the effect of its attacks in California was ascribed to a fungous disease, and it was not until the writer visited the lemon districts about San Diego Bay in 1896, and identified the injury as due to the Florida rust mite, that its true nature was known. Our knowledge of its life history and habits and the remedies for it are chiefly due to the work of Mr. Hubbard in Florida. This mite develops on both the leaves and fruit, although its presence on the former is often overlooked. On the foliage the presence of the mite causes the leaves to lose their gloss and become somewhat curled, as though by drought. The leaves are never killed, however, the attack resulting merely in the considerable checking of the vigor of the plant. . The presence of this mite affects the fruit of the lemon slightly dif- ferently from that of the orange. The ripening fruit of the orange, after having been attacked by the mite, becomes more or less rusted or brownish, and the rind is hard- ened and toughened. While the orange loses its brilliant fresh color and gloss, the toughening and hardening of the rind enables the fruit to stand long shipment, and protects it very materially from decay + “The quality of the 4. 33.—The rust or silver ‘mite (Phytoptus olei- juice is rather improved by the vorus Ashmead). a and 6, dorsal and lateral y : fs views of adult mite; c, leg of same; d, egg; e, mite than otherwise, the mite- jemonrind showing pits normal to surtace and attacked oranges being more juicy mites and eggs—all greatly enlarged, (a to d copied from Hubbard; e, original.) and sweeter flavored. As a re- sult of this, a demand grew up in the Northern markets for the rusty fruit, and good prices were obtained for it. In the case of the lemon, however, an injury to the rind is an impor- tant consideration, a perfect rind being a requisite of the fruit, on account of the numerous uses to which the rind is put and the valuable products obtained from it. The effect on the lemon is also somewhat different from that on the orange. The rind of both fruits, when attacked by this mite in the green stage, becomes somewhat pallid or *‘silvered,” due to the extraction of the oils and the drying up and hardening of the outer layer of the skin. This whitening is much more marked with the lemon than with the orange, and, since the iemon is often picked while green, the subsequent rusting is not nearly so nota- ble; hence, in California this mite is known chiefly as the silver mite. If the lemon is allowed to fully ripen on the tree, however, it also becomes bronzed or rusted, but rather lighter in shade than the orange. 172 40 As in the case of the orange, the rind of the lemon is hardened and toughened, but the juicy contents are not affected materially; further- more, a silvered lemon will keep very much longer than a perfect lemon, and will bear long shipment without risk of much loss. Until very recently the rusted lemon in southern California found no market whatever, and was a total loss to the grower. The scantiness of the crop in 1900 resulted, however, in some shipments of rusty fruit being made under the name of ‘‘russet lemons,” about half the normal price being obtained. Should the manufacture of citric acid assume very much importance in southern California, the mite-injured lemons could be used for this purpose. Nevertheless, considering the ease with which the mite may be controlled, there is no excuse for allowing it to maintain itself in injurious numbers in a lemon grove, since, irrespec- tive of the appearance and value of the fruit, its work on the foliage materially lessens the healthfulness and vigor of the plant. The rust mite avoids exposure to sunlight, and hence the lower half of the fruit is nearly always first invaded, and only gradually does the mite work its way around to the upper surface, very frequently a small portion exposed to the direct rays of the sun remaining unattacked. This gives the appearance, most prominently shown in the case of the orange, of a discolored band extending about the fruit. The multipli- cation of this mite goes on at all seasons of the year in the orange and lemon districts, being merely less prolific and active in winter than in summer. It has been supposed in Florida that dry weather is inimical to it, but the fact that it thrives in southern California would seem to throw doubt on this belief. The rust mite itself is very minute (fig. 33), practically invisible to the naked eye. It is honey-yellow in color, and about three times as long as broad. It is provided with four minute legs at its head extremity, by means of which it drags its wormlike body slowly from one spot to another. The eggs are circular and are deposited singly or in little clusters on the surface of the leaf or fruit. They are about half the diameter of the mother and nearly transparent in color, having, how- ever, a slight yellowish tinge. They hatch in four or five days in hot weather, but in cold weather the egg stage may last for one or two weeks. The newly hatched mite is very similar to the adult. About a week after hatching, it undergoes a transformation, or molt, requir- ing a period of about forty-eight hours, after which it escapes from the old skin, which remains adhering to the leaf or fruit for some little time. This moult brings the mite to its adult stage, in which it is somewhat darker in color than the young and opaque. No sexual differences have been discovered, and the number of eggs deposited by a single mite is not known. The entire development of the mite is short, probably not much exceeding, in warm weather, two weeks. The food of the mite seems to be the essential oil which is abundant 172 41 in all the succulent parts of citrus plants, and which is obtained by the mites by piercing the oil cells with their beaks. These mites, while excessively minute, are capable of very active locomotion, moving from one part of the leaf to another, as the con- ditions of light and food necessitate. An estimate, made from actual count, indicates that the mites and eggs ona single leaf in midwinter may reach the enormous number of 75,000. This indicates for trees, in the active breeding season of summer, billions of mites. The mite is very readily distributed by means of insects and birds. The rust mite is readily destroyed by various insecticides. The eggs, however, are much more difficult to kill, and practically no wash can be relied upon to reach and destroy all the eggs of this mite. Experience in California indicates that gassing is also ineffective against the eggs. The sovereign remedy for the rust mite is sulphur. It may be applied as a powder on trees, and, moistened by rain or dew, will adhere to the leaves for quite a long period, not being readily washed off even by a bard rain. When spraying is done for scale insects, the flowers of sulphur can be mixed and applied with the spray, accomplishing both purposes at once. A better method, perhaps, is to first dissolve the sulphur with lye, as follows: Mix 20 pounds of flowers of sulphur into a paste with cold water, then add 10 pounds of pulverized caustic soda (98 per cent). The dis- solving lye will boil and liquefy the sulphur. Water must be added from time to time to prevent burning, until a concentrated solution of 20 gallons is obtained. Two gallons of this is sufficient for 50 gallons of spray, giving a strength of 2 pounds of sulphur and 1 of lye to 50 gallons of water. An even stronger application can be made without danger to the foliage. This mixture can also be used in combination with other insecticides. There are several species of mites which attack citrus plants, the most troublesome one of which, especially in Florida, is the one named above. Almost any insecticide will kill the adult mite, such as kero- sene emulsion, resin wash, or even a simple soap wash, but unless the eges are killed the trees will be reinvaded about as thickly as ever in the course of a week or ten days. The advantage of the sulphur treat- ment arises from the fact that the sulphur adheres to the leaves and the young mites are killed as soon as they come in contact with it. THE SIX-SPOTTED MITE. This leaf mite or spider (Zetranychus sexmaculatus Riley—tig. 34), is closely allied to the common red spider of greenhouses. It first made its appearance as an important orange pest in Florida in 1886. Fol- lowing the severe freeze of the winter of 1885-86, the weakened trees 172 42 seemed to be especially favorable for the multiplication of this mite; it increased suddenly in enormous numbers during the dry weather of the early summer and was responsible for very considerable damage to the foliage of the orange. The original food plant of this mite is unknown. It was first noted on wild orange, from which it spread to other citrus trees. It is prob- ably a native of Florida. Like its allies, this insect is greatly influenced by climatic conditions, and needs for its excessive multiplication dry hot weather: Therefore, in rainy seasons it is not especially troublesome, and it usually disap- pears as soon as rainy weather setsin. In Florida its period of greatest destructiveness falls between February and the middle of May. This mite was carried to California a decade or more ago with Florida stock, doubtless at the same time that several other Flor- ida citrus insects were transported to the Pacific coast. In California, how- ever, the principal mite injury seems to be due to an allied species, also brought from Florida, 7. mytilaspidés.“ The attacks of the six-spotted mite are confined largely to the under sides of the leaves, which are covered with a fine web, beneath which the mite feeds. The first indication of its presence is usually a yellowing in streaks and spots of the upper surface of the leaves. The under surface becomes soiled by the Fic. 34.—Six-spotted mite of the orange : (Tetranychus sexmaculatus): a, dorsal accumulated excrements in the form of ve ofaga mite vat enter minute black spots and by the web of aici ficom Se Lite). the mite. On badly attacked trees the foliage curls and shrivels and the trees may lose half or more of their leaves, and similarly also a large per- centage of the half-formed fruit. Being an accompaniment of drought in Florida, part of the damage may undoubtedly be ascribed to the effect of the dry weather. The remedies are the same as for the rust of silver mite. The bisul- phide of lime is also an effective wash. It can be made very cheaply by boiling together in a small quantity of water equal parts of lime and sulphur. Five pounds of lime and 5 pounds of sulphur, dissolved by boiling, should be diluted to make 100 gallons of spray. Gassing “s ineffective. — “See Bul. 145, Cal. Agr. Expt. Sta., for detailed account of this species. 172 '@) West: > ei ba: Khe me ai, ¥ _ ; Siem be? | TAD: 1 £ fat Y a Urs. DEPARTMENT OF AGRICULTURE. FARMERS’ BULLETIN No. 178. INSECTS INJURIOUS IN CRANBERRY CULTURE. BY JOHN B. SMITH, Professor of Entomology, New Jersey Agricultural College. mani y i py) NARMS ae Hy MO ee y WASHINGTON: GOVERNMENT PRINTING OFFICE. £903. LETTER OF TRANSMITTAL. U. S. DeparTMENT oF AGRICULTURE, Division oF ENTOMOLOGY, Washington, D. C., June 29, 1903. Str: I have the honor to transmit herewith an article on Insects Injurious in Cranberry Culture, prepared by John B. Smith, pro- fessor of entomology, New Jersey Agricultural College, and recom- mend that it be published as a Farmers’ Bulletin. Respectfully, ne . O. Howarp, Entomologist and Chief. Hon. James WILson, Secretary of Agriculture. 178 3 ‘ Woes hes ey oe Lac te ‘ ‘i SEGhVY lad ay OT EH RR tte APPAR: ena is | t0itod ey; 3) ‘ Vres: ° ‘7 TAME TE ‘S BV ast-§ F Ud inde, CAete A e Se SEER A SRG My sins 7s. re Srkha ‘ a3 ae i Freer ' Pri whe none ; Introduction ....<..--. CONTENTS: Mee Chin OLincevbWe [OUADEC..2 oa oe eicicu sede s eho ee cdua ee oe eete dase es The blackhead cranberry worm (Hudemis vacciniana Pack.) .....-------- The yellowhead cranberry worm ( Terias minuta Rob.)...---.------------ Natural checks Flowing th Reflowing. SERS Ce ere ere a as OR et cy te ee WRGCUICICOH Semen ace een en tae aee tS CSN eee ete Ss eee The cranberry tip worm (Cecidomyia oxycoccana Johns. )..----------- Remo inlWicasgres soos tet we Sue act So eae ee eee The cranberry spanworm (Cleora pampinaria Gn.).....------------- Remiemial MCAsULeH S22 o soe so coe cos ee ee ens Coes ee Soar Giner eranberry-leat feadera2 2222. 255 52.6 aeis 2 Sac Fsoe ee ee aee ineeie puis atte tHe stem. 2.22 Soa Soe eh ees sa 22 sree The cranberry girdler (Crambus hortuellus Hbn.)--......---------------- bedicctal Measired we vc = ene ER ee oats aoc cease ee me ceine Riaeetsriiat QtiaCk the Mit 2+ 22 5. - tec os ecto t ack Goce ce vee dene bee See The cranberry fruit worm ee UECCHIBEEMOYs) = ne). eer nels eee Temi MEASNLed Noo. ote ee oe Hoa ee ao aoe ne eee The cranberry katydid (Scudderia texensis Sauss.)...-------------------- Pretec eal gM Ses UP ees. oae es as fl ee Mc ices tin he ioe ar CMbSnappers ane CniCkKels seme. |. eM oo eo ee Lateline aoe wena Fe eO el IMGARONES . atone er See ee os och swe oen See The ideal cranberry bog 178 Fig. ILLUSTRATIO . Moth of blackhead cranberry worm -.---.-- . A cranberry leaf, showing eggs of blackhead.........-...----------- . First web of larva of blackhead -.-...-.--- . Blackhead cranberry worm, larva and pupa NS. Examples of feeding and of webbed uprights.........-..-.---------- . Yellowhead cranberry worm, larva and pupa ....--.---------------- VUcaiMerny Wp WOrm -. 20-50%... 5556505 ene PV Op Oo bi WORM oocc- tas sce L oko se Wwranvery pirdler os. scouts socek ect bese Mian perry. init Worm .¢. 25.6226 ch ela ked . A cranberry-eating katydid .........--....- . Tip of a spray of Panicum viscidum .....--- INSECTS INJURIOUS IN CRANBERRY CULTURE. INTRODUCTION. The method of cultivating cranberries is so radically different from that employed for any other crop, and the character of the soil on which the plants grow is so unlike that on the ordinary farm, that it is not surprising to find the insect enemies more or less peculiar in character and the methods of dealing with them unusual. The general practice is to cover the bogs with water during the winter, and this excludes from them quite a variety of insects that might otherwise prove troublesome. In a few localities where winter flowage is impossible, some insects that are not usual on other bogs do injury, and these must be dealt with as similar species would be treated if affecting upland crops. With a bog properly located, properly laid out, and a suitable amount of water supply to cover it promptly in case of necessity, the cranberry grower need fear none of the insect pests so far known as injurious to the crop. Roughly speaking, the species of insects injurious to cranberries are divided into such as affect the foliage, such as attack the stem, and such as injure or destroy the fruit. Under the first head come the leaf folders, like the black and the yellow head cranberry worms, the tip worm, and the different spanworms which appear in variable numbers each year. Under the second head comes the stem girdler, which eats the bark of the stem or runners and thus kills the plant beyond the point of attack. Under the third head comes the berry worm and the various grasshoppers and katydids that eat of or into the fruit. INSECTS THAT ATTACK THE FOLIAGE. THE BLACKHEAD CRANBERRY WORM. ( Eudemis vacciniana Pack. ) @ This is perhaps the best known and most uniformly injurious of all cranberry insects and is locally known as the ‘* vine worm” in Massa- chusetts and as the ‘‘fireworm” in New Jersey. As a larva (worm) it is a deep, rather velvety, green, slender little caterpillar, not over « Also mentioned in entomological writings as Anchylopera and Rhopobota. 178 9 10 half an inch long when full grown, and with a shining black head and neck. The adult is a small moth or ‘‘ miller” with narrow, dusty- brown wings that measure less than half an inch when expanded and seem much smaller because they are so slight. More closely examined the fore wings will be found to have alter- nate light and dark gray-brown shade bands, obliquely arranged as shown in fig. 1. The moths first appear on the bogs in early June, continuing until nearly the end : of the month, and again late in July, con- Fic. 1—Moth of blackhead cran- tinuing into August, when they disappear i oa for the season. During the day little is seen of them unless the vines are disturbed, when they flutter away for a short distance, concealing themselves so closely as to be almost undiscoverable unless the actual point of settling has been noted. In the early evening and until the darkness sets in fully they are on the wing and hover a short distance above the plants like a swarm of mosquitoes. Though the moths themselves have disappeared for the season before the end of August, they have left, scat- tered everywhere on the undersides of the leaves, their minute yellow eggs (fig. 2). These eggs are flattened, disk-like, and less than half the size of an ordinary pin head, but their bright yellow color makes them easily visible against the green of the leaf, even without a Fie. 2—A cran- magnifier. There they remain throughout the winter, ae whether the bog be dry or flowed, and the little cater- of __ blackheaa pillars hatch from them in spring as soon as the tempera- ture reaches an average of about 60 degrees. Many of the eggs perish during the winter, but where the vines are uncovered in sheltered spots they hatch out little worms about the time the vines themselves are making a start. For a day or two the worms nibble on the under surface of the old leaves or may even burrow into them and then make their way to the tip of an upright, where they spin together the edges of the new leaves. The experienced grower, if he walks among his vines a few days after they have made a start, can tell at a glance to what extent his bog is Cetin, Sr meaner infested by the closed tips (fig. 3) that are promi- of blackhead (after nent because the light undersides of the leaves penta. are visible. In about three weeks from the date of hatching, the caterpillar is full grown, lines the inside of its shelter more fully and closely with fine silk, and changes to a stubby little yellowish-brown pupa (fig. 4). In a week the transformation is com- 178 hE pleted and the moth appears about the 1st of July. The bog at the beginning of July shows very plainly the effects of the insect’s attack in brown tips that are everywhere noticeable; and every brown tip at this time means a barren upright. Next the leaves drop and the burnt appearance disappears for a few days, but this is only to give way to another series of spun-up tips which resemble those of the early brood, but with a difference. The vines are now in full foliage, full of buds and almost ready to bloom. Unlike those of the first brood, the worms of this second brood are not content to spin up only a single tip; they gather into their web every- Fic. 4.—Blackhead cranberry worm; a, larva, b and ¢ thing within reach (fig. 5). pupa—enlarged (author’s illustration). Two or three sprays with all their buds may be included and every chance for fruit destroyed. In fact, the buds, flowers, and very young berries are eaten by preference, and the injury to the crop is out of all proportion to the amount of plant tissue actually de- voured. So, also, in- stead of eating up a leaf entire, the worms take a few bites here and there until, to- ward the end of July, the bog appears as if it had been burnt over, justifying the term ‘‘fire-worms” for the insects. The egg stage for this second brood is Fig. 5.—Examples of feeding and of webbed uprights (author’s less than a week in illustration.) length, the larvee (worms) mature in about fifteen days, and by the middle of July the moths are again out in full force. Egg laying is in full swing before the end of the month and these eggs do not hatch till the next 178 . 12 year. The cranberry vines will recover in appearance, and by the middle of August look green and flourishing; but if the worms have been numerous there will be no berries. Remedies.—The question of remedial measures will be considered after the description of the next species, as the two need similar treatment. THE YELLOWHEAD CRANBERRY WORM. ( Teras minuta Rob.) @ This insect is.much more abundant in New Jersey than it is in Massachusetts, and in some localities in the latter State it does not seem to occur as a cranberry feeder at all. It is quite as plentiful on Long Island as it is in New Jersey, and wherever it occurs is apt to be even more injurious than the preceding species. The common name here used describes the most conspicuous differ- ence in the larval (worm) stage from the preceding species, and is employed in preference to the term ‘‘ vine worm” under which it used to be best known in New Jersey. In this species the eggs are not on the bogs during the winter. On the contrary, the moths themselves hibernate in any shelter they can find—in cranberry houses, barns, or other buildings; under bark or bark scales on trees, and in numerous other places where they may find protection from the direct influence | of the weather. At this season the moths are uniformly slate gray, inconspicuous, much broader winged than the moth of the ‘* black- head worm,” and apparently much larger in every way. They are on the wing as soon as vegetation starts in spring and are ready to lay their eggs during the latter part of Apriland early May. They prefer cranberry if they can get it; but if not, make a shift with huckleberry or some allied plant, or even with apple. Wherever cranberry vines run up on the dams above the water line, or are otherwise not sub- merged, eggs are laid on the underside of the leaves. These eggs resemble those of the blackhead species so closely that, except for their fresher, brighter appearance, no differences can be observed even with a good hand lens. By the middle of May in New Jersey, and perhaps a little later in Massachusetts, all the moths have disappeared. This habit is an important one from the practical point of view and gives in some localities practical control of the insect. The eggs hatch in a week or ten days—depending much upon the weather—the worms make their way to the tips and spin together the terminal leaves, exactly as do those of the preceding species. The yellow head is practically the sure mark to tell this kind from the blackheads. « Treated in works on economic entomology, also, as Teras vacciniivorana Pack. 178 13 This matter of distinguishing between the two is of decided impor- tance, because, while the feeding habits are similar, there are vitally important differences that affect remedial measures. The yellowheads are, on the whole, stouter than the blackheads, and, as a rule, lighter in color. They are also less active and, especially when nearly full grown, do not so readily wriggle out of their nests. The yellowheads grow fast, and are ready to pupate late in May or very early in June, a little before the blackheads. The second moths appear early in June, but are now bright orange red in color, whereas the first moths were slate gray. The second lot of eggs hatch toward the end of June, and the yellowhead worms are nearly half grown when the cranberries are in full bloom, early in July, when the second brood of blackheads has just started. They make even larger webs than the blackheads, and are even fonder of boring into the fruit. It is not uncommon to see half a dozen uprights and runners all tied together in one large web, in which leaves, even if not eaten, turn brown and die. By the mid- dle of July or a little later the yel- lowheads are again full grown and change to pup. The worms spin a silken cell, in which the change takes place, and the pupa (fig. 6) is dark brown or blackish, with a little knob-like protuberance on the head case. This peculiarity makes the species easily distin- . , Fie.6.—Yellowhead cranberry worm; a, larva; guishable from the same stage of b and c, pupa—much enlarged (author’s jllus- the blackheads. — frelon): The third crop of moths appears late in July or early in August and are of the same orange-red color as the second. Eggs laid by these moths do not hatch until in August or even early in September, and the worms that come out of them grow slowly as compared with the earlier broods. Few of them spin up more than a single shoot and few of them eat into any but the smallest berries. They also tend to become reddish in color and even striped, so that at one time they were believed to form a distinct species, described as the ‘* red-striped cranberry worm.” Not until after the picking, if anything be left to pick, do these worms become full grown. Very irregularly in late September and early October they come to maturity, and now the moths that come from them are, after a dust of orange wears off, of the slate-gray color seen in spring. 178 14 NATURAL CHECKS. The blackhead worms are little, if any at all, subject to parasitic attack. The check for these seems to come in the mortality among hibernating eggs. Only a small fraction of those that are on the plants in midsummer survive to hatch during the following spring. But while the blackheads are kept within certain bounds by these natural conditions, they do very serious injury to the cranberry crop. The ‘‘ yellowhead ” (Teras) is much more subject to parasites, though the first brood of worms is but little attacked. In the second brood matters have changed, and out of a given number of worms collected near maturity less than 50 per cent became adult. In the third brood conditions are yet further modified and not over 25 per cent of the worms develop to the adult stage, leaving, however, a goodly number to go into the winter. During this season many others die off because of adverse weather conditions, but still enough remain. In general, on any given infested area, both of these cranberry worms will hold their own and even increase under natural conditions. The grower has nothing to hope for from the ordinary checks provided by nature. REMEDIAL MEASURES. Flowing the bog.—The application of insecticides on large bog areas where the plants cover the ground as densely as do the cranberry vines is a task no grower likes to contemplate; and provided he has control of a satisfactory amount of water there is no necessity for it. As against the ‘‘ yellowhead” (Teras), it will suffice if the water be held on the bogs until the middle of May, or perhaps a little later in cold seasons. By this time the huckleberry and heath plants have made a good growth and have tempted the hibernating moths to lay their eggs. Unless, therefore, the vines are uncovered at the edges or on knolls above water, the plants will be free from the first brood of worms. In the woods and on the upland plants the worms and even the moths are exposed to the attacks of birds and many predatory insects that never go upon the bogs; hence the adults of the first summer brood will not be nearly as plentiful as if they had bred on the vines. Only a few, comparatively, of the moths will fly upon the bogs, and even then do not usually get very far from the edges; so the heavy, very injurious middle brood will be reduced to practically harmless numbers. The third brood, even if it does spread over a greater area, is not likely to prove troublesome, for reasons already stated. Hence, care and attention to the drawing of the water in spring will of itself suffice to keep this insect in check. If to this we add the destruction of the heath and huckleberry plants immediately surrounding the 178 ‘15 bogs, the nearby breeding places are further reduced and the bog is the more likely to remain free. As against the blackhead late holding will not of itself suffice, because the eggs are already on the plants and will, under ordinary circum- stances, hatch only under the same conditions that favor the start of vines themselves. But there is a little leeway in favor of the plants, and the eggs do hatch under water at a temperature not quite sufficient to start the vines. To hatch the eggs the proper temperature only is needed; to start the vines there must bealsosunand air. If, therefore, a bog is tolerably level the water may be drawn from below until it just covers, and may be held there even after May 15, until the starting of the vines indicates that the danger point has been reached, and then it must be drawn to avoid killing the fruit buds. Runners or laterals not bearing fruit buds will stand a quarter or even half an inch start under water without danger unless the water is drawn on a very warm day, and then there is danger of scalding. The further advanced the plants the greater that danger becomes; hence great care and good judgment must be exercised when this measure is adopted. Fruit- bearing uprights can not be safely permitted to make more than a mere start. On a sloping bog, where the water is deep at the gates and becomes shallow at the edges, the water may be gradually drawn from the bottom so as to leave the warmer surface water, and in this way practically all the eggs will come under the influence of the moist heat that favors their development. Carefully carried out, this measure is often very effective; the warmth favors the development of the embryo within the egg, and when the worm hatches it drowns. Occasionally a specimen may bore into a leaf and so maintain itself twenty-four hours or more, but usually it stifles without getting even a bite. Sometimes badly infested bogs are completely freed by this method without apparent injury to the setting of fruit, yet at times the crop is reduced one-half by holding a little too late. In the latter case, however, the crop had been destroyed by the insect for several years in succession, and the owner was quite willing to sacrifice 50 per cent if thereby he got rid of the insect, as he did. This method should be employed only when reflowing is not possible. Reflowing.—When the supply of water is abundant above the bog area, so that a pond or reservoir may be formed, both the yellow and blackheads may be completely controlled by drawing the water early, waiting until all the eggs have hatched and some of the worms are nearly half grown, and then re-covering the bog with water for forty- eight hours. This method is so simple and so absolutely effective that the larger growers are adopting it almost universally, and few new bogs are laid out anywhere without considering the matter of reflowage and 178 16 providing for as good a control of the water as possible. Under proper control the water may be drawn from the bogs when the best interests of the plant demand it without any regard to insect conditions. If worms appear in any number toward the end of May, the bogs are reflowed, and rarely is this necessary more than once in three years. Only when the bog area is small and the surroundings are very bad is annual reflowage needful. For a complete effect the vines should remain covered forty-eight hours, because it requires some time for the water to penetrate the spun-up leaves so as to kill the worms. Many, indeed, especially the half-grown blackheads, wriggle out, seeking to escape when the water reaches them, but those nearing maturity are less active, remaining at home until the water surrounds them and they simply can not get out. Covering the bogs should begin in the late afternoon and should be completed before next morn- ing, if possible. Ona rainy day it may begin at any time, the object being merely to prevent the sun from boiling the young shoots. So drawing off the water should also begin in the early afternoon, and the bog should be practically dry the morning after. Incidentally, this reflowing will rid the bog of numerous other pests and may make a material impression on the girdle worm where that is abundant. The importance of a sufficient water supply has come to be so gen- erally recognized among advanced growers that in New Jersey miles of ditches tap streams far away from the bogs, and in Massachusetts expensive pumping machinery has been installed to raise water in large quantities to high-bog areas. It is sometimes possible to use the upper one of a series of bogs as a reservoir, holding a full head of water as late as it is safe to reflow the lower bogs of the series which have been drawn early. In one series of 100 acres, divided into 5 sections by cross dams, a fall of about 10 feet is utilized to reflow all save the uppermost section, and this practice is possible in almost every case where water is available. Insecticides.—Sometimes it happens that bogs can be neither winter flowed nor reflowed, and the application of insecticides becomes an absolute necessity. Only arsenites are to be relied upon for good results, although for a long time tobacco was and in some parts of Massachusetts is yet the main reliance. It follows from what has been said concerning the habits of the worms that when once they have spun up the tips and are feeding in their cases they are practi- cally beyond the reach of our common insecticides; and that is partic- ularly true of the first brood. If there is reason to believe from past experience, or because eggs have been found on the plants, that the early brood will be numerous, spraying must be done just as soon as the vines make a start or not later than the date when the first spun-up tip is seen. The object is to get the poison into position before the leaves are spun up, so that the worms may find their first meal poi- 178 17 soned. If spraying for the first brood is omitted, that for the second brood should be timed in the same way, and, because the worms now spin up a greater amount of vegetation, the chances of killing them off are greater. All things considered, the best insecticides for use on cranberry bogs is arsenate of lead, either in the paste form as sold by certain makers of insecticides or made up by dissolving separately 4 ounces arsenate of soda and 7 ounces acetate of lead in water enough for that purpose, then combining the solutions in a tank to which 50 gal- lons of water may be added. If the paste arsenate is used, 1 pound in 40 gallons is better. Any sort of machine or pump may be used and any nozzle that - makes a reasonably fine spray. The point to be aimed at always is the terminal growth, because it is there that the insects feed. Noth- ing will be gained by driving the mixture into the body of the vines, especially if they are long and densely matted. The conditions on the bogs vary so much that every grower must determine his outfit accord- ing to his own needs. In some cases horses can be used on the bogs to draw a geared machine of large capacity; in others they are out of the question; and so the size of tank from which the spraying is done and the way in which it ismounted must vary according to circumstances. It may under some conditions be more satisfactory to apply a dry insecticide, and for this purpose there are now several ‘‘ dust sprayers” and ‘*powder guns” on the market. By means of a fan blower a fine powder can be rapidly and evenly distributed over a large area, and this would naturally lodge just where it was needed. A good mixture for such application is 1 pound of fine Paris green to 10 pounds of dry hydrate or fresh air-slaked lime. The lime should be sifted, thoroughly mixed with the Paris green, and the combination applied while the vines are slightly moist. ' THE CRANBERRY TIP WORM. ( Cecidomyia oxycoccana Johns. )@ This is a minute orange-red or yellowish grub (fig. 7, @), about one- sixteenth of an inch in length, found in the growing shoots, whether uprights or runners. It is comparatively rare on Cape Cod and is not common on all the New Jersey bogs, though more plentiful there than anywhere in Massachusetts. It appears on the vines soon after they make a start, and the first indication of its presence is when the small leaves of the tip cease to unfold and become bunched into a com- pact, bulb-like mass. When this mass is opened, from one to five, @Has been described and figured also as C. vaccinii Sm., not Osten Sacken. 178 4382—No, 178—03——2 18 and usually two or three, of the little grubs will be found at the very heart of the growing tip, feeding upon the juices and completely check- ing growth (fig. 8). If it is a runner that is attacked, it is destroyed; if a fruit-bearing upright, the flower buds come out below the infested tip and no harm is done to the crop. But the insects continue to appear on the bogs at intervals through- out the season, and the danger is that the late- tipped uprights will form no fruit buds for the next year. The little grub is rather _ 6 wa ahelpless sort of a crea- Fic. 7.—Cranberry tipworm; a, larva; b, breast bone; c,mouth ture, without legs and even parts—much enlarged (author’s illustration). without distinct jaws; but it has on the underside of the body a little horny process or breast bone by means of which it scrapes the plant tissue until the cells break down and their contents may be absorbed. In about ten days it reaches full growth, envelops itself in a thin, white, silken cocoon, Fie. 8.—Work of tipworm (author’s illustration). and two or three days thereafter changes to an adult—a minute, two- winged fly or midge whose wings when expanded measure less than an eighth of an inch from tip to tip. The male is quite uniformly yellowish-gray and inconspicuous, but the female has the abdomen 178 19 deep red, the upper surface of the body gray, the sides yellowish, the head and eyes black. She also has a slender, extensile tip to the abdomen, by means of which the minute white eggs are laid in the very heart of the bud. After the fly has emerged from one of the infested cranberry tips the leaves that were massed together turn red or brownish, die, and break off, leaving a stub above the fully developed leaves. If the tips are killed early in the season fruit buds may form at the axils of the leaves, or one or more little spurs may start lower down on the shoot, at the tips of, which normal fruit buds may develop. On new bogs, with young, vigorous vines, the early broods cause no damage at all and the late broods very little. On old bogs, with long vines, the ear- lier broods do little harm, but the later broods materially injure the crop prospects for the year following by preventing the set of buds on the injured uprights. Remedial measures.—Strictly speaking, no direct remedial measures are known. It is not known positively how the insect passes the win- ter; hence control can not be attempted at that season. The worm never comes within reach of our ordinary insecticides, and therefore direct attack is not possible. Since the loss of the tips attacked in spring does not injure the crop of that year, the effort must be to keep the vines in such vigor that they will set fruit buds on laterals and at leaf axils when the direct tip has been lost. How this vigorous growth is to be obtained the grower will be best able to determine. This insect is not confined to the cranberry, and in fact breeds much more abundantly on loose strife (Lysimacha) and on some of the heaths. Therefore, where the species is troublesome, those plants should be kept down on the dams and other bog surroundings. Tip worms occur on both flowed and dry bogs, and reflowing does not reach them; but as they first occur on flowed bogs around the edges, the inference is that the winter is passed on the upland, on or in some one or more of the alternate food plants. This would make the destruction of such plants an effective measure. THE CRANBERRY SPANWORM. (Cleora pampinaria Gn. ) @ 6 99 665 In some sections of Cape Cod certain ‘‘ span,” ‘‘ inch” or ‘‘ measur- ing worms” occasionally become injuriously abundant, and the most destructive of these is the species above named. The parent moth is much larger than any of the other forms found on the bogs, the broad fore wings expanding 13 inches or thereabouts. In general color it is pale ash gray, sprinkled with black, and both wings are crossed diag- @ Also known as Boarmia pampinaria, etc. 178 20 onally by black lines and shades. The lines have a tendency to become toothed or scalloped, and the wing margins themselves are also a little notched. The worms first appear on the bogs in June and become full grown by the end of that month or early in July. They are then rather more than an inch long; slender, smooth, livid gray caterpillars with a deeply indented head and a long, pointed anal plate. They have three pairs of short legs close behind the head and two pairs near the anal end. When they walk, they first stretch out at full length, take hold with the anterior legs, then bring the posterior pairs close to the others, the middle of the body forming a loop. This mode of progression gives them the common name ‘‘ loopers” in addi- tion to those already mentioned. At rest or when not feeding, the caterpillars hold fast by the anal legs only, and stretch out the remain- der of the body at an angle, and so rigidly that they resemble leafless bits of vines. Ona section of bog on which they have been feeding the observer may stand in the midst of thousands of them and see none until something starts them into motion; then it appears almost as though the entire bog was alive. When full grown they bury themselves a short distance beneath the surface and change into rough, brown, rather stubby pupe, from which the moths emerge a few days later. The second brood of cater- pillars matures early in August, and pupation begins before August 9. — Though worms will continue to be present in numbers until after the middle of the month, the moths appear at its end and in September. There seems to be no regularity in the appearance of these insects. In some years they are not seen at all; in others they may be locally abundant, and only occasionally do they seem to occur everywhere in greatarmies. Usually they start from some point near the edge of the bog, spread out a little, and then move in an almost direct line ahead. Sometimes the beginning is nearer the center, and the eating may be in all directions from a given point where some groups of eggs were laid. It is the first brood which, as a rule, starts near the edges. The second brood starts from inside centers, and when these are numer- ous the boundaries of the individual broods become lost, and, the — masses uniting, an army is formed which, as it advances, plays havoc with the crop. Not a green thing is left on the yines, and in a few days acres may change from green to brown; from a smiling promise of a full crop to the barrenness of desolation. Remedial measures.—Being an open feeder upon the foliage, this span worm is susceptible to arsenical poisoning, and unless the bogs can be rapidly reflowed and as rapidly laid dry, spraying or dusting are the only alternatives. Where the worms are noticed when they first start, spraying the foliage just ahead of them may answer all pur- poses, and indeed this poisoning of their line of advance should always be done before treating the parts already infested. Either Paris green, 178 21 at the rate of 1 pound in about 160 gallons of water, may be used, or the arsenate of lead or a dry powder may be applied, as for the black- heads and yellowheads. So, also, the machinery to be used and the manner of application may be along the lines suggested on page 17. OTHER CRANBERRY LEAF-FEEDERS. Quite a number of species other than those already mentioned occur on cranberry foliage from time to time and cause local, though usually slight, injury. The caterpillars of some of the ‘‘owlet moths” are always found in small numbers; but, except for the army worm, none have ever caused widespread trouble. As army worms can not live over on the bogs and must come on from the outside, a broad marginal ditch, well filled with water, will be a perfect barrier to their injury. Spanworms are much more common, and the striking yellow and black larve of the white, chain-dotted geometer are sometimes as plentiful in New Jersey as in Massachusetts; but usually they are on bogs that run up into the huckleberry and heath bushes. They are not strictly cranberry feeders, but will run into the bogs when they become unusually abundant or when for any reason their normal food supply is scant. Leaf hoppers of various species are more or less common always, and sometimes quite abundant; but, though they undoubtedly drain the plants to some extent, they seem to cause no injury to the crop. Leaf rollers other than the yellowhead and blackhead cranberry worms are occasionally found. They usually make webs of such dif- ferent forms that they are readily distinguished from the common species. None of them live exclusively on the bogs, and generally they do not appear until after midsummer. A saw fly larva (worm) is sometimes found on New Jersey bogs and often eat little round holes in the young berries. It makes no sort of web and feeds only at night, its injuries being thus more readily found than the insect itself. None of these species is of sufficient importance to demand more detailed notice here. As a rule the injury done is so slight that it will not pay to adopt remedial measures. If real damage is threatened, the arsenical applications are indicated except in the case of the leaf hoppers. INSECTS THAT ATTACK THE STEM. THE CRANBERRY GIRDLER. (Crambus hortuellus Hbn. ) This species (fig. 9), more commonly known as the “‘ girdle worm,” is found abundantly in all the cranberry districts, but it is seriously injurious in Massachusetts only. The larvee, which are slender, gray- 178 22 ish caterpillars, with shining, light chestnut-brown heads, and yellow- ish thoracic shields, pass the winter in a torpid condition within a silken tube or cocoon, which resists the entrance of water. In New Jersey the adults are found in May, on and around the edges of the bogs; in Massachusetts they do not fly until July, and there is evidence that the worms do some feeding in spring before they actually change to the pupal stage. This change to the pupa takes place in the tube or cocoon made in the previous fall, and on Cape Cod at the latter part of May orinearly June. The adult isa pretty little creature, with fore wings expanding about three-fifths of an inch, and is one of the long-snouted moths, the palpi or mouth feelers projecting well beyond the head. The fore wings are rather narrow, very pale straw-yellow in color, with smoky lines in the interspaces between the veins and narrow silvery cross bands at the outer part, near the margin. The hind wings are much broader and of a uniform silvery gray. When the moth is at rest the wings are so closely wrapped around the body that it looks like a narrow whitish cylinder about three-quarters of an inch in length. The young worm is very active and strong, and at once begins the construction ; : i of the silken tube, reen- olin — NY | — forced by bits of vegetation, v : i) in which it lives. It works about the running portion of the plants extending along the surface of the sand in the stratum of fallen leaves which always cover Fie. 9.—Cranberry girdler; a, moth; b, egg; ec, larva; an old cranberry bog and d, segment of larva; e, pupa; jf, nest of larva—all 4 : enlarged (after Scudder). from which the delicate clusters of new rootlets take their rise. Everywhere over an infested area, but especially along its borders, these worms can be found in filmy silken galleries following the prostrate stems of runners, into the surface of which they eat their way, destroying the vital part of the plant and, especially next to the base of the runners, deeply gir- dling the stem. They grow rather slowly, and not until] November do they make their coarse cocoon of mingled sand and silk that serves as winter quarters. It seems probable that in Massachusetts there is only one brood of the moths which is active in July. In New Jersey, on the other hand, the moths have been found in every month from about May 21 to the middle of September. There must be, therefore, at least two broods, which develop very irregularly. With this difference in the life cycle in the two States there is an evident divergence in food habits, for 178 € 23 there is no such destruction of large tracts in New Jersey as is found in Massachusetts. That the insect is not specifically a cranberry feeder is proved not only by the fact that it occurs not uncommonly many miles away from any cranberry plantation, but also by the direct evi- dence of an investigator who actually bred it on the common grasses and found further that the worms would eat freely of sheep sorrel. The cranberry feeding habit seems to be, therefore, a somewhat local characteristic and this gives hope that by persistent work this bog variety may be in large part stamped out. An infested bog is rarely affected over its entire extent. Small areas varying from a few feet in diameter to half an acre or more are found here and there, and sometimes a little patch only a foot or two across will remain for two or three years in succession without becom- ing enlarged, but rather it will become closed up by runners from the adjacent healthy vines. Larger areas tend to become larger, new vines dying from the edges each year. A restart over areas so killed out is very slow, yet it does usually occur after the second year; but the growth is apt to be irregular and requires some time before it comes again into bearing condition. Remedial measures.—It is quite obvious that insecticides are not available here, because of the concealed feeding habit, and that resort must be had to more direct methods. Light traps to capture the adults have proved unsatisfactory, very few specimens having been taken in this way. Experiments show that the worm in its silken case will bear submergence in water for over four days without fatal results, and it is known that in its cocoon it bears submergence during the entire winter. But the insect does not make this cocoon until November, and a submergence of five days immediately after the picking is completed destroys a great many. The suggestion is therefore made that, immediately after the fruit is off, infested bogs be flowed and be kept covered for at least a week, and better two weeks. This should be effective against these worms and harmless to the vines. While the ripening fruit is on, any water covering kept on over twenty-four hours would be apt to do material injury. An additional suggestion is that the actually infested area be com- pletely burned off as soon as its extent can be determined. The vines already attacked are doomed at best, and if in destroying them the insect can be also killed the loss will be balanced by a greater benefit. For this burning a gasoline torch may be employed, and the heat thus applied directly to the point where it will be most effective. The use of the torch will also prevent setting a fire that might injure other portions of the bog, since it can be used when the vines are so wet that they will not burn under ordinary conditions. The burned-over area can be immediately reset and the actual amount of injury limited to a minimum. 178 24 If burning is resorted to, it should be done as early in the season as possible and should be extended far enough to cover the entire infested portion of the bog. INSECTS THAT ATTACK THE FRUIT. THE CRANBERRY FRUIT WORM. ’ (Mineola vaccinii Riley. ) This is another species that is much more injurious in Massachusetts than in New Jersey, though it is by no means unknown in the latter State, and in some seasons and localities does considerable damage. As a rule, bogs that can not be reflowed and high and sandy bogs suffer more. The adult moth (fig. 10) appears on bogs in ordinary seasons about the middle of July, when the berries are setting or have already set. It is probable that the moths remain on the bogs for a period of at least a month, as indicated by the very unequal development of the worms that are found in the berries in early September. The moth, with wings expanded, measures about three-fourths of an inch and is of a glistening ash-gray, mottled with white and_ blackish. ‘Lhe forewings are narrower than the jo ete eal aici ee Samael hind wings, which are more smoky coon; h, moth—all enlarged (after Riley). | gray in color and have no markings. It is a shy species, not easily started during the day, and flies with a darting motion for quite long distances. It is not generally recog. nized, therefore, even by growers who annually lose heavily by it. When at rest the wings are folded close to the body, and on a cran- berry stem, where it usually rests head down, it is not readily seen even by an experienced eye. The eggs are laid on the young berry, preferably in the calyx, just beneath one of the lobes, but they may be on any part of the berry and possibly on the leaves as well. They are very slightly convex, almost flat, round in outline, pale yellowish in color, and so soft that they adapt themselves readily to any inequalities of surface. The worms emerge in about five days, and for‘a day or two feed on the outer side of the berry. Then each worm enters a berry, eats out the seed cham- ber, and migrates to another. The vacated berry turns red, shrivels up, and eventually drops. The worm, on entering its new home, care- fully closes the opening behind it with a web of fine silk, so dense that it is sometimes difficult to see where the hole was made. In this sec- ond berry it becomes half grown, then works out through a large 178 25 jagged opening and gets into a third berry, closing the point of entry as carefully as before. By this time the season is pretty well advanced, the fruit is of good size, and, soon after the worm starts feeding, the newly infested berry begins to turn red. To the ordinary observer the fruit is ripening nicely, if early; but the grower knows better and realizes that every such specimen is lost to him. Not unusually the worm completes its growth in this berry, but if it does not it eats into afourth. This time it makes no attempt to seal up its point of entry; very often it spins together a little cluster of berries, eating from one into the other and ruining all of them. Full growth comes, asa rule, in late August or early September, just before picking time; then the cater- pillar leaves the berry and in the sand at the base of the plants spins a rather close silken cocoon, in which it passes the winter. But quite frequently the worms do not get their full growth at picking time, and emerge from the berries after they are harvested and in the cran- berry house. These delayed forms make their way to any crevice or other shelter that they can find and there spin up for the winter rest. At this time the worm is rather more than half an inch in length, of a bright-green color, witha variably marked reddish tinge on the back. The head is a little narrower than the first body segment and is of a more yellowish color, except the mouth, which is brown. The body segments are transversely wrinkled, clothed with a few sparse, rather long hairs. As a whole, this is decidedly the stoutest of those occur- ring on the bog as injurious species. The full-grown caterpillars winter in their silken cocoons, which they make by first rolling in the sand, gluing the particles topettin with saliva, and then spinning their we inside of the rough casing so formed. Pupation begins toward the middle of April with specimens that have been dry during the winter, but probably not much before the end of May or early June on the bogs. The pupa is brown, rather chunky, and of the same general form as in the species already described. Remedial measures.— Winter flowage is not fatal to these insects, and covering the bogs with water at any time after the winter cocoon has been formed would probably be ineffective. Nevertheless, as already indicated, water-covered bogs are less troubled, and it is probable that the earlier the water is put on in the fall the more effective this practice will be. Indications are that if a bog can be safely submerged for forty-eight hours between August 10 and 15, just before the worms reach their full growth, the great majority will be killed off. Sound berries coy- ered for that length of time will not come to harm if the water can be put on and drawn off rapidly enough to avoid scalding. Fruits not quite so far advanced may be covered for even a longer time without injury, but there is always a risk which the grower should fully con- sider before he acts. The vines should be completely covered before the sun beats upon them high enough to warm the water, the covering 178 26 should be sufficiently deep to prevent a scalding effect, and when the water is drawn sunrise should find at least every berry above the water level, that the drying off may be gradual. A cool day would almost insure safety to the berries, an intensely hot one might cause injury, and the nearer maturity the fruit the greater the danger. Nevertheless, despite the danger, reflowage is advisable, provided it can be done within the time limit given. If reflowage be not practiced, pick the crop as soon as it is at all practicable, so as to get as many wormy berries off the bog as may be. The worms will emerge in the cranberry house and form their cocoons in cracks and crevices or among rubbish. Give them plenty of shelter in the way of loosely piled slats, boards, or other cover, placed wher- ever conveniently possible, and any time during the winter clean up thoroughly, so as to reach the hibernating worms. Field mice will eat these worms. Also a liberal use of gasoline in such places under the usual precautions against fire would reach every one of them. Insecticides are possible only during the two or three days in which the young worm feeds on the outside of the berry, and the only mate- rial that offersany chance of good results is arsenate of lead. If when the worm starts feeding it finds a poisonous meal prepared its career will be ended at once. It must be remembered that any application to be at all effective must be on the berries by July 10 and must be maintained there at least a month to get most of the hatching worms. Arsenate of lead is the most lasting of all the arsenical sprays, but new berries are being added constantly as new fruit sets, and at that season growth is rapid, so that a week will add a large amount of new, uncovered surface. One spraying per week for three, or preferably four, weeks offers a fair chance of success by killing off the berry worms before they get into the berry. On bogs that can not be flowed the arsenate of lead, aided by early picking, will probably reduce the amount of injury materially; but on such bogs the development of the moths may occur earlier and the grower must rely more upon the stage of growth, or, better, the appearance of the moths themselves on the bog, than upon any abso- lute dates. Methods of applying the arsenate and of preparing it have been already given on page 17. THE CRANBERRY KATYDID. (Scudderia texensis Sauss. ) One of the most destructive insects on the New Jersey bogs isa species of katydid (fig. 11), though its injuries are, as a rule, charged to grasshoppers in general. On Long Island the damage is less marked, and in Massachusetts the insect is practically unknown. 178 27 The injury is chiefly caused by the feeding habits of the adult of one species of Scudderia which chews into the berries when half to full grown, rejects the pulp, and eats the seeds. Other species belonging to Microcentrum and other genera have similar habits, but occur more rarely. The injured berries wilt, shrivel, and die; but when they have just been left by the katydids, the common, shorthorned grass- hoppers feed on the exposed pulp and, being detected in this, are quite generally charged with having caused the entire trouble. One katy- did may eat out several berries at one sitting, and when the insects are at all abundant the percentage of fruit destroyed is very large; on some bogs the amount reaches almost or quite one-half the entire crop. S gate \e2 Fig, 11.—A cranberry-eating katydid (after Riley). The katydids when mature are green, grasshopper-like insects, with very long antennee, or feelers, and long slender hind legs. The fore wings are also green and are narrow, a little thickened, not used in flight. The hind wings are decidedly longer, much broader, very much thinner, almost transparent, and longitudinally folded under the fore wings when at rest. Fully expanded, these wings measure from 2 to 24 inches between tips, and the body is about 14 inches in length. In the male there is a little triangular area at the base of the fore wings where they overlap, and where a few ridge-like veins form a musical instrument by means of which they produce their chirping song or call. In the female this structure is absent, but we find at the end of the abdomen a broad scimitar or sickle-shaped ovipositor, by means of which the eggs are laid. The young wingless katydids are found around and at the edges of the bogs about the middle of June, but do not mature until early in the following August. Not until they reach the pupal stage, after the middle of July, does the berry-feeding habit become developed, but from that time until the fruit is picked their fondness for this kind of food increases, and the insects themselves increase in number on the bogs. The first eggs are laid about the middle of September and the laying continues until about the same period in October. By that time the insects have disappeared and nothing more is seen of them until June of the following year. The eggs are laid chiefly in two kinds of grasses, locally known as “deer grass” (fig. 12) and ‘‘double-seeded millet,” scientifically re- 178 é 28 corded as Panicum dichotomum and P. viscidum, respectively, the latter being very decidedly the favorite. The latter, Panicum viscidum (fig. 12), is a grass which grows in large tufts or clumps of from 20 to 30 stems, from 2 to 4 feet high, or perhaps 5 feet where it is found in thickets or fence corners. The whole plant is thickly covered with long, soft, velvety, somewhat sticky hairs. The stems are at first not branched and have from 8 to 10 leaves shaped like a narrow peach leaf, those at the top being very small. In summer and fall these stems branch from each joint and ‘the branches keep on branching again and again, producing large numbers of small leaves and giving the plant a very bushy and tangled appearance. The seeds are borne ina small head at the top of each stem and later of each branch, these heads being something like a very small and loose sorghum head or more like a head of broom-corn millet or hog millet. Fig. 12.—Tip of a spray of Panicum viscidwm— The other grass, Panicum dicho- reduced (after Smith). : ° . a Ae tomum, is much like Paniewm visei- dum, but is very much smaller, scarcely over 18 inches high, and grow- ing in smaller tufts. The stems are slender and weak, and the plant is not at all hairy. It also branches freely in summer and fall. Where growing in the sunshine the stems are usually purplish. Occasionally eggs are laid on other grasses or plants, but never on cranberry leaves. They are laid chiefly at night on the drier parts of the bog, in the edges of the leaf between the upper and the under surface, to the number of from one to five in one blade; the single number is much the more usual. When deposited the egg is very flat, almost three-sixteenths of an inch long, less than half as wide, slightly kidney shaped and of a very light yellowish brown color. The disk of the egg is closely and roughly marked or netted without definite pattern. Remedial measures.—The character of the remedy to be adopted fol- lows from the egg-laying habits of the species. Allow none of the host grasses to maintain themselves on the bogs and burn over the dams during the winter while the bogs are flowed. From the fact that the very young katydids are never found on flowed bogs except at the 178 29 edges joining the upland or at the base of the dams, it may be fairly inferred that the eggs do not survive the winter when kept completely submerged, so that destruction of the grasses above the water line might answer. It would he safer, however, to have the grasses out; they have no place on the bogs anyway. For burning the grasses and other host plants on the dams some one of the gasoline torches now on the market may be used. They give a very intense heat and lick up leaves and plants with extreme rapidity. As they can be used against the wind or while the plants are somewhat damp there is practically no danger that the fire will get away, and when the ground is frozen, the covering of leaves and stalks is burned so rapidly that no heat gets to the roots. Growers consider it desir- able to keep a cover of vegetation on the dams to strengthen or pre- vent them from washing, and this method will destroy the egg-bearing vegeta*ion without also destroying the plants themselves. GRASSHOPPERS AND CRICKETS. Numerous short-horned and long-horned grasshoppers may be found on and about the bogs, and more or less injury is charged to them. As to the common gray or brown short-horned grasshoppers the charge is believed to be practically unfounded. They do sometimes finish up berries that have been opened by the katydids; but direct evidence is lacking that they would or even could get into a sound berry. Nor do they occur in any numbers on clean, well-kept bogs, free from grass and from overgrown edges or dams. They belong naturally in the grassy undergrowth along the margins, and simply run over when there is an easy opportunity. It is rather otherwise with some of the long-horned, green, meadow grasshoppers, which on grassy, reedy, or sedgy bogs are sometimes present in immense numbers. All of these are fond of seeds, and while the smaller species can not get into a half or full grown berry, the larger species can, and so they join the katydids in their destructive work, but in comparison do little injury. Most of them have a long, flat ovipositor, straight or slightly curved, and they lay their eggs in the stems of the sedges, rushes, and larger grasses found on the bogs. None of these species can cut into leaves. Their eggs are long, slender, nearly cylindrical, and often just a little curved. They are laid in series of anywhere from three to eight, one above the other, the number of eggs in any series depending upon the length of the ovipositor in the species. Where bogs are very full of these little species, a large proportion of the grasses and sedgy plants will be found bearing eggs, and these eggs are so well protected that they survive the winter though they be completely submerged. Accordingly, in early June thousands of 178 30 the little meadow grasshoppers are found just hatched and under such conditions that they could not possibly have come on from the outside. Remedial measures.—The only way to keep these species off the bogs is to keep down the grasses. They are not naturally feeders upon the cranberry plant, and exact so small a toll that the actual loss is less than the probable cost of getting rid of them. If the grasses, etc., can not be readily taken from the bogs, they might be mowed, after picking, above the vine level. This would cut off the parts bearing the eggs, and as the loose grass would float when the water is put on, the eggs would either be carried to the edges or would decay with the vegetation containing them. Crickets also occur in greater or less numbers on most bogs, and growers are by no means agreed whether they cause injury or not. That they will eat berries on the ground, especially under cranberry crates, is certain; but it is not proved that they ever go upon a vine to feed upon a berry attached to it. The species lay their eggs in sandy soil, and never in wet or mud land; so, as a matter of fact, no field crickets can really propagate on the bogs. But they get into the dams, and oviposit in warm sandy places, so that the young may hatch early in the spring and find their way to the moist, warm places in which they delight. Their range of food seems to be wide, and there is almost nothing they will not eat under favorable conditions; but they live on the ground and rarely get out of the shelter of the vines or upon them. If it be deemed desirable the crickets can be kept off the bogs almost entirely by broad, clean, marginal ditches maintained at least partly full of water. The crickets rarely if ever fly, and, while they are good swimmers, do not ordinarily attempt to cross any ditch 6 feet wide. A flowing just after picking would destroy most of the grasshopper and cricket tribe that then occur in their greatest number. THE IDEAL CRANBERRY BOG. So much has been said of bog conditions,.and bog conditions so greatly influence the abundance of injurious species of insects, that it may not be out of place to describe briefly what a bog should be to make insect control easy and certain. (1) The bog should be as nearly level as it can be made, so as to require the least possible amount of water to flow it. A bog that can be completely covered by a 12-inch head is better than one that requires 24, and when the difference in level of an area is 5 or 6 feet or more it is better to make two bogs out of it, that the lower may be reflowed from the upper. and less than half the amount of water be required. 178 31 (2) Make no one bog so large that more than thirty-six hours are required to cover completely, and no more than twenty-four hours are required to draw the ditch level. (3) Build a reservoir or reserve a flooded area above the level of the highest bog of a series sufficient to hold water enough to flow at least the highest bog completely. The importance of this requirement is so fully appreciated that miles of ditches have been dug in New Jersey to tap streams at a higher level, and many acres of swamp area have been created by raising contour lines to deepen natural basins. In Massachusetts powerful pumps have been installed to pour water directly upon the bog or into a reservoir above it. (4) Adjust bog levels so that the upper one of the series can be com- pletely emptied into the one below, and yet have the gates and outlets so adjusted that any one bog may be completely emptied without inter- fering with either those above or those below. It happens not infre- quently that one bog needs cleaning or other attention while others do not. (5) There should be a broad, deep, marginal ditch between the dam and the bog or between the bog and upland, and this ditch should be always clean and at least partly full of water. Many kinds of insects can be altogether kept from the bogs in this way, while grasshoppers and other insects are delayed until they can fly. Then they are feed- ing on other things, and they do not often change the food habits of their early life. (6) The dams and the edges of the uplands should be kept as free as possible from vegetation that harbors cranberry-feeding species. Cranberry vines should not be tolerated for an instant. Huckleberry bushes are almost as bad, and these should be cleared back for some distance where bog and upland join without an intervening dam. Other heath plants are also undesirable and should not be allowed too near the bogs nor on the dams. (7) It follows from what has been said that the bog itself should be kept as free as possible from all plants other than vines, certain grasses being especially objectionable because they are used by long-horned grasshoppers as places to lay their eggs. Bogs so arranged could be kept completely safe at all times, and once properly laid out would require little outlay to keep them so. The question whether bogs should be kept wet or dry, whether there should be many or few ditches, and whether these should be deep or shallow need not be here considered at all. The dates of flowage and reflowage and other points of measurement by means of which con- trol may be made effective have been already touched upon. The important advantages are that neither insecticides nor spraying machinery would ever be required, and the insect problem would be reduced to the simplest possible terms. 178 32 FARMERS’ BULLETINS. The following is a list of the Farmers’ Bulletins available for distribution, showing the number and title of each. Copies will be sent to any address on application to any Senator, Representative, or Delegate in Congress, or to the Secretary of Agri- culture, Washington, D. C. The missing numbers have been discontinued, being superseded by later bulletins. : No. 16. Leguminous Plants. No. 21. Barnyard Manure. No. 22. The Feeding of Farm Animals. No. 24. Hog Cholera and Swine Plague. No. 25. Peanuts: Culture and Uses. No. 27. Flax for Seed and Fiber. No. 28. Weeds: And How to Kill Them. No. 29. Souring and Other Changes in Milk. No. 30. Grape Diseases on the Pacific Coast. No. 31. Alfalfa, or Lucern. No. 32. Silos and Silage. No. 33. Peach Growing for Market. No. 34. Meats: Composition and Cooking. No. 35. Potato Culture. No. 36. Cotton Seed and Its Products. No. 37. Katir Corn: Cultureand Uses. No.38. Spray- ing for Fruit Diseases. No. 39. Onion Culture. No. 40. Furm Drainage. No. 42. Facts About Milk. No. 48. Sewage Disposal on the Farm. No.44. Commercial Fertilizers. No. 45. Insects Injurious to Stored Grain. No. 46. Irrigation in Humid Climates. No. 47. Insects Affecting the Cotton Plant. No. 48. The Manuring of Cotton. No. 49. Sheep Feeding. No. 50. Sorghum as a Forage Crop. No, 51. Standard Varieties of Chickens. No. 52. The Sugar Beet. No. 53. How to Grow Mushrooms, No. 54. Some Common Birds. No. 55. The Dairy Herd. No. 56. Experiment Station Work—I. No. 57. Butter Making on the Farm. No. 58. The Soy Bean as a Forage Crop. No. 59. Bee Keeping. No. 60. Methods of Curing Tobacco. No. 61. Asparagus Culture. No. 62. Marketing Farm Produce. No. 63. Care of Milk on the Farm. No. 64. Ducks and Geese. No. 65. Experiment Station Work—II. No. 66. Meadows and Pastures. No. 68. The Black Rot of the Cabbage. No. 69. Experiment Station Work—III. No. 70. Insect Enemies of the Grape. No. 71. Essentials in Beef Production. No. 72. Cattle Ranges of the Southwest. No. 73. Experiment Station Work—IV. No. 74, Milk as Food. No. 75. The Grain Smuts. No. 76. Tomato Growing. No. 77. The Liming of Soils. No. 78. Experi- ment Station Work—V. No. 79. Iixperiment Station Work—VI.. No. 80. The Peach Twig-borer. No. 81. Corn Culture in the South. No. 82. The Culture of Tobacco. No. 83. Tobacco Soils. No. 84. Experiment Station Work—VII. No.85. Fish as Food. No. 86. Thirty Poisonous Plants. No. 87. Experiment Station Work—VIII. No. 88. Alkali Lands. No. 89. Cowpeas. No. 91. Potato Diseases and Treatment. No. 92. Experiment Station Work—IX. No. 93. Sugaras Food. No. 94. The Vege- table Garden. No. 95. Good Roads for Farmers. No. 96. Raising Sheep for Mutton. No. 97. Experi- ment Station Work—X. No. 98. Suggestions to Southern Farmers. No. 99. Insect Enemies of Shade Trees. No. 100. Hog Raising in the South. No. 101. Millets. No. 102. Southern Forage Plants. No. 103. Experiment Station Work—xXI. No. 104. Notes on Frost. No. 105. Experiment Station Work—XII. No. 106. Breeds of Dairy Cattle. No. 107. Experiment Station Work—XIII. No. 108. Saltbushes. No. 109. Farmers’ Reading Courses. No. 110. Rice Culture in the United States. No. 111. Farmer’s Interest in Good Seed. No. 112. Bread and Bread Making. No. 113. The Apple and How to Grow It. No. 114. Experiment Station Work—XIV. No. 115. Hop Culture in California. No. 116. Irrigation in Fruit Growing. No. 117. Sheep, Hogs, and Horses in the Northwest. No. 118. Grape Growing in the South. No, 119. Experiment Station Work—XV. No. 120. Insects Affecting Tobacco. No. 121. Beans, Peas, and Other Legumes as Food. No. 122. Experiment Station Work—XVI. No. 123. Red Clover Seed. No. 124. Experiment Station Work— XVII. No. 125. Protection of Food Products from Injurious Temperatures. No. 126. Practical Suggestions for Farm Buildings. No. 127. Important Insecticides. No. 128. Eggs and Their Uses as Food. No. 129. Sweet Potatoes. No. 130. The Mexican Cotton Boll Weevil. No. 131. Household Tests for Detection of Oleomargarine and Renovated Butter. No. 132. Insect Enemies of Growing Wheat. No. 133. Experiment Station Work—XVIII. No. 134. Tree Planting in Rural School Grounds. No. 135. Sorghum Sirup Manufacture. No. 136. Earth Roads. No. 137. The Angora Goat. No. 188. Irrigation in Field and Garden. No. 139. Emmer: A Grain for the Semi- arid Regions. No. 140. Pineapple Growing. No. 141. Poultry Raising on the Farm. No. 142. The Nutritive and Economie Value of Food. No. 143. The Conformation of Beef and Dairy Cattle. No. 144. Experiment Station Work—XIX. No. 145. Carbon Bisulphid as an Insecticide. No. 146. Insecticides and Fungicides. No. 147. Winter Forage Crops for the South. No. 148. Celery Culture. No, 149. Experiment Station Work—XX. No. 150. Clearing New Land. No. 151. Dairy- ing in the South. No. 152. Scabies in Cattle. No. 153. Orchard Enemies in the Pacific Northwest. No. 154. The Fruit Garden: Preparation and Care. No. 155. How Insects Affect Health in Rural Districts. No. 156. The Home Vineyard. No. 157. The Propagation of Plants. No. 158. How to Build Small Irrigation Ditches. No. 159. Scab in Sheep. No. 160. Game Laws for 1902. No. 161. Practical Suggestions for Fruit Growers. No. 162. Experiment Station Work—XXI. No. 163. Methods of Controlling the Boll-Weevil. No. 164. Rapeasa Forage Crop. No. 165. Culture of the Silkworm. No. 166. Cheese Making on the Farm. No. 167. Cassava. No. 168. Pearl Millet. No. 169. Experiment Station Work—XXII. No. 170. Principles of Horse Feeding. No. 171. The Control of the Codling Moth. No. 172. Seale Insects and Mites on Citrus Trees. No. 173. Primer of Forestry. No. 174. Broom Corn. No. 175. Home Manufacture and Use of Unfermented Grape Juice. No. 176. Cranberry Culture. No. 177. Squab Raising. No. 178. Insects Injurious in Cranberry Culture. No. 179. Horseshoeing. No. 180. Game Laws for 1903. No. 181. Pruning. No. 182. Poultry as Food. No. 188. Meat on the Farm. —s ™ VY ¢ Lt EY Ae ath U. S. DEPARTMENT OF AGRICULTURE. FARMERS’ BULLETIN No. 18g. INFORMATION CONCERNING THE MEXICAN COTTON BOLL WEEVIL. BY Ww. D. HUNTER, Special Agent in Charge of Cotton Boll Weevil Investigations, Division of Entomology. WASHINGTON: GOVERNMENT PRINTING OFFICE. ‘ : 1904. LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Division oF Entromo.oey, Washington, D. C., January 11, 1904. Srr: I have the honor to transmit herewith an article entitled ‘**Information Concerning the Mexican Cotton Boll Weevil,” by Mr. W. D. Hunter, special agent of the Division of Entomology in charge of the cotton boll weevil investigations. Owing to the great impor- tance of the subject and the urgent demand for all possible informa- tion before planting, I urge its immediate publication as a farmers’ bulletin. Respectfully, L. O. Howarp, Entomologist. Hon. JAMES WILSON, Secretary of Agriculture. 189 ane nt Bo. an ‘ Pe Bi 4 “ : mi : fj he ey < WERE XE Feet Po he OP Ve a Mater s swag ee a wy eres: * ix hs , 3 j \ ' . y & a a hae Oh a EAE he Teh AE GETS Ree r U8 a altel ah al ips ER EE 20 OS Bs ee Rese QO ee ls ge ah eS Pw) Mer eae DNR OT Ys Meet en Re SS DE ee Os 3.22222 esos noe ee Seen eee ee ee ee 8 he pollworm-sOnicOM. 22. 4 282 ee ee eee eos See eee 9 The bollworm ‘on cotton -s\24-<.. acs. sees ne hoe ne Ss eee ae ee 10 Some factors which tend to keep bollworms reduced. -.....--.-------------- 14 Ineffective methods of bollworm control -.-..-------- RR SEES rote te SO clas 15 Iaichts for trapping Moths... 5s ec see ce ak a ates a2 2 a oe eee ee 15 Poisoned! sweets: ---...-22--222- 2 SIS SICCE LS See sess Nee eee 15 Burning sulphur in cotton fieldse: 2. S25. £2558. -- sneer 16 Resistant: varieties. <= 5... 22S ca. cee eae ae eee ns he i ee eee 16 Bield'experiments in 1903 22.7: Bice esses fee es eee 16 CGultural‘methods' 2.2.42 S286 22 eee oe eee ere eee 16 AyseniGal pOlsONS: .=-=243 Seee ees nee oe ee eee oe eee 19 Com asa trap Crop. s22e Seeeeer ase tea ae ee es oc eee eee 21 Specific recommendations... s2h5.22 noi2 4 oda se ont tee eee en Sees eee 22 ILLUSTRATIONS. Page Fic. 1. Map of Texas, showing territory ravaged by bollworm in 1903..-.---- 5 2. The bollworm moth, about twice natural size...:...------..-.------- 7 3. Young corn plant, showing i injury to the ‘‘bud”’ by the bollworm .. - - 10 4. Roasting ear infested by bollworm 54d Rok Bo te ee eres Soe pe 11 5. Normal, and ‘‘flared’’ cotton square due to bollworm injury --.-..---- 1 6. Cotton -boll and bollworm, showing mode of attack..--...-----.----- 13 7. Opened boll, to show bollworm at ‘work withuniesenee 208) k ees 14 191 : 2 THE COTTON BOLLWORM. INTRODUCTORY. The so-called bollworm, the larva of the moth //eliothis armiger Hbn., has long been known as an important enemy of cotton. As early as 1841 it was found in the cotton fields around Tallahassee, Fla., where, in the course of a few years, it became quite destructive. It was seriously injurious to cotton in Alabama in 1847, in Mississippi in 1850, and in Louisiana in 1867. By 1879 it had become the principal insect enemy of cotton in Texas, and at the present time ranks second in importance only to the Mexican cotton boll weevil. This insect was early the subject of investigation by the General Government. In the Patent Office Agricultural Report for 1854, Townend Glover gave an excellent article on the bollworm, detailing the principal points in its natural history. The results of the work of the Division of Entomology and of the United States Entomological Commission on this insect from about 1878 to 1881 are displayed in Com- stock’s Report on Cotton Insects, and in the Fourth Report of the United States Entomological Commission by Professor Riley. A sup- plementary investigation of the bollworm was made by Professor Mally, under the direction of the Division of Entomology, in the early nineties, and the results are set forth in Bulletins 24 and, 29 (old series), issued in 1891 and 1893 respectively. More recently (1897) an account of this species has been distributed in Farmers’ Bulletin No. 47 (Insects Affecting the Cotton Plant), by Dr. L. O. Howard. As aresult of these several publications a knowledge of the boll- worm’s life and habits, and of the best methods to be employed in its control, has been quite widely disseminated. Nevertheless, little if any effort has been made by planters during the many years of bollworm injury to check its ravages, and, along with the increased cultivation of cotton from year to year, often to the exclusion of any other crop, the losses from this insect have tended to increase rather than to diminish. . The considerable injury done by the bollworm during the past two or three years, notably in certain portions of Texas, led to provision by Congress for a further investigation of this insect by the Division of Entomology, and the writer was detailed to the work in Texas. 191 3 4 Headquarters were established at Victoria, where office and other facilities were available in the laboratory of the force engaged in investigations relating to the cotton boll weevil. Such laboratory investigations as were possible were conducted, but special attention was given to field work, this being considered of more importance in view of the many facts already known about the life and habits of the bollworm. Through the cooperation of the agent charged with boll- weevil investigations, arrangements were made for the growing of cotton on the contract plan with planters at Calvert, Willspoint, and Hetty, Tex., including in all 140 acres. The locations chosen are fairly typical of the respective sections, and in two the bollworm had been especially destructive the year previous. INJURY IN 1903. Aside from certain isolated’ localities here and there in the cotton belt, bollworm injury during 1903 appears to have been confined mostly to Texas and to the southern portion of Indian Territory. The accompanying map (fig. 1), indicates the area most seriously ravaged in Texas. Injury was especially severe in some of the north Texas counties, as Fannin, Lamar, Delta, Hunt, Hopkins, Kaufman, and Van Zandt; and also in the central Texas counties, Navarro, Hen- derson, Limestone, Falls, Bell, and Robertson, the loss in each of these counties being variously estimated at from 20 to 60 per cent of the crop. It is hard to arrive at even an approximate estimate of the loss, owing to the difficulty of securing trustworthy data. The tendency to exag- gerate losses from insects is well known, as is also the tendency to attribute to insect depredations the disastrous effects which may result from changes in the weather or from other conditions. The shaded portion of the map includes the principal cotton-producing area of the State, from which, in 1902, came approximately three-fourths of the total cotton product of Texas. Throughout this area bollworm ray- ages were reported as more or less extensive in 1903. A conservative estimate of the injury, based on data secured from various sources and from personal observations, it is believed would be approximately 96,000 bales, which, at a valuation of $50 per bale, would mean a loss of $4,500,000. If to this amount be added the value of the cotton seed the total loss sustained would easily exceed $5,000,000. According to the estimate of Professor Mally, bollworm injury in Texas in 1902 amounted to approximately $4,750,000, and the area most seriously ravaged coincides rather closely with that injured in 1903. It may also be said that the shaded portion of the map marks approximately the area of greatest corn production, and the simple rotation of corn with cotton, so largely practiced, has undoubtedly contributed to the seriousness of the bollworm situation at the present time. 191 pain, ay k It is recorded from Germany, ’ It occurs through- out most of the United States, and is reported from many localities in Central and South America and the West Tndies. ance ngland, Fr DISTRIBUTION. E urope, as of E countries The bollworm has a world-wide distribution. s variou Dr. WIRE rae = MAX E NON Ste \ Ss Hh) \\ iN = AS SS > ag oO jes a a Wy je Zz < oO Zz \E 3 he) JAC pure LAHOMA YOUNG STEPHEN HROCKM oC [~) He : HAKELF. ICALLAH JON : ae o 2 EDWARDS ENT SUTTON SCHLEICHER HALL MOTLEY BOR MITCHELL DICKENS (CURRY Ga g ERUN MEE Xl CuO n on WwW It Fic. 1.—Map of Texas, showing territory ravaged by bollworm in 1903. 191 and Russia; and also from the Canaries, Kongo, South Africa, New Zealand, Australia, Ceylon, Java, India, Japan, China, and Hawaii. is not possible to determine the origin of the bollworm. 6 It is of interest to note that the species was described from Europe in 1796, while its first recorded occurrence in the United States was in 1841. GENERAL APPEARANCE AND LIFE CYCLE. Throughout this bulletin the common appellation of this insect in the cotton belt, namely, the bollworm, is adhered to. It need hardly be explained that the larva known variously as the budworm of corn, the tassel worm, corn earworm, and tomato fruitworm, is identical with the cotton bollworm. The egg.—Bollworm eggs may easily be detected with the unaided eye, and may be most: readily found on the fresh silk of corn. They are oval in shape, whitish or yellowish in color, and average in diameter about 0.45"™ to 0.5". Examined under a hand lens, they are seen to be sculptured with polar ribs and cross furrows like those on the eggs producing the cotton caterpillar. The eggs of this latter species, however, are much flatter and greenish in color, and are, therefore, not likely to be confused with those of the species under considera- tion. The eggs of the bollworm hatch in from two and one-half to six days, depending on the temperature. The larva.—The insect is most commonly known in this, the boll- worm, stage. It is only during this larval existence that injury is inflicted. Newly hatched bollworms are very small and are usually quite overlooked by planters until they are of sufficient size to attack the buds, squares, and young bolls. As the larve grow, a remarkable diversity of color and markings may become apparent, ranging from whitish or greenish without decided markings of any kind, to indi- viduals which are rose colored or almost black, with distinct spots and dorsal and lateral longitudinal stripes. This color variation has been the source of some confusion as to the identity of the larva, particu- larly when on other plants than cotton. The bollworm is a voracious feeder and grows rapidly, completing its growth during summer in from twelve to fifteen days. During the cool weather of spring and fall its rate of growth is much slower. A full-grown larva measures from 1} tc 14 inches in length. The body is stout and tapers slightly toward the head and caudal extrem- ities. In the darker individuals the markings consist of a narrow, dorsal, central, longitudinal, black stripe, centered with a fine white line. On each side of the body, including the breathing pores, is a broad, whitish, lateral stripe, extending from the head to the last seg- ment. Just above this lateral stripe is a broad, dusky, longitudinal band, and between this latter and the central dorsal stripe is a broad whitish band, often marked with fine whitish lines, but so delicate as not to interfere with the general color of the body. On the more central body segments are usually eight black spots, extending in an 191 7 irregular transverse line from one stigmatal stripe to the other. The breathing pores are black in color, the head brownish, and the entire ventral portion light. The pupa.—When full grown the bollworm leaves its food plant, burrows below the soil surface some 2 to 5 inches, and constructs a more or less upright cell, reaching to near the surface of the ground to allow of the ready exit of the moth. At the bottom, the tube is somewhat more enlarged, and here the larva sheds its skin and enters the quiescent pupal stage. There is considerable variation in the method of pupation, depending on the character of the soil, and not infrequently this stage may be entered within the ear of corn or the cot- ton boll in which the larva was feeding. The pupal stage during sum- mer lasts from nine to twelve days. The adult.—The parent moth, like the larva, is extremely variable in general color, ranging in different individuals from a dull ochre-yellow to a.dull olive-green. The wing ex- panse is about 14 inches, and the body is about seven-eighths of an inch in length. The males may be most readily distinguished from the females by the stouter abdomen of the latter. The accompanying illus- tration (fig. 2) shows the bollworm moth in a rather characteristic posi- tion, and will aid in its identifica- tion, where help is needed. Life cycle.—From the above state- ments as to the length of the re- Fie. 2.—Bollworm moth in natural position, spective stages, it is seen that the Las folded; about twice natural size (orig- insect may go through all of its transformations from egg to adult, during summer, in about twenty- three to thirty days. The average of six individuals reared during June and July, at Victoria, Tex., was twenty-eight days. During spring and fall the rate of development is much slower. The average time for the complete life cycle of nine individuals during the spring at Victoria was forty-four days. FOOD PLANTS. The bollworm is practically omnivorous, and the list of plants upon which it has been found feeding is very large. In the United States it is destructive principally to corn, cotton, tomatoes, and various gar- den crops. The combined annual loss from this species in this and foreign countries must be very great, and easily places the bollworm among the foremost injurious insects of the world. 191 8 NUMBER OF GENERATIONS. The number of annual generations of the bollworm in the cotton belt varies from about four to seven, depending on the latitude, with an average of about five. Owing to the irregularity in time of appear- ance of moths from the ground in the spring and the variation in rate of growth of different individuals from various causes, there results a considerable breaking up of generations, so that these are rarely marked. Thus, in 1903, in Texas, the insect in all stages, from egg to adult, was to be found in considerable numbers in the same field at any given time throughout the season. ‘This condition, however, may have been due in part to the lateness of the season. Furthermore, there may be numerous distinct generations in the same locality, or even on the same plantation, depending on the relative age of the different fields of corn. It is therefore evident that in considering the generations of the bollworm only the majority of the individuals may be referred to. In general, the moths are out in maximum numbers in the spring in any locality in the cotton belt at a time when field corn is mostly from 8 to 20 inches high, and they deposit by far the greater part of their eggs on these plants. The first generation of bollworms feeds mostly on the tender central roll of leaves of the young corn, the moths from these larvee appearing during late May or early June. These likewise oviposit largely on corn, which by this time may be com- mencing to tassel somewhat and to show young ears, the larvie feeding on the buds, unfolding tassels, and forming ears, as the case may be. Moths from this, the second, generation of larvee make their appear- ance from late June until early July and deposit eggs on corn, espe- cially on the silks, which are now appearing quite generally. The third generation of bollworms infests the soft milky ears of corn dur- ing early July, and the moths appear again late in July or early in August. By this time, however, the corn throughout the country has begun to dry and the ears to harden and is no longer attractive to the moths for egg laying. They therefore fly to neighboring cotton, from which they secure nectar as food, and on which they deposit the greater part of their eggs. The more or less simultaneous hardening of corn during late July results in a general migration of the moths to the cotton fields, and injury to cotton during August from the fourth generation of bollworms may often be very extensive. Not infrequently, however, cotton may be severely ravaged by the fifth generation during late September or early October. Larvee of the fifth generation attain full growth usually by the middle of October, burrow into the ground, and transform to pup, in which condition the majority remain during the winter, the moths appearing the fol- 191 9 lowing spring in time to oviposit on young corn. If, however, the autumn is warm, a small proportion of the pups may transform to moths, which oviposit again on cotton, and a few bollworms are thus to be found in cotton fields until the plants are destroyed by frost. It is supposed that a few of the late-appearing moths may hibernate as such during the winter, and hence appear early in the spring, thus adding to the confusion of generations, but the evidence on this point is far from satisfactory. THE BOLLWORM ON CORN. Corn is, without doubt, the preferred food of the bollworm, and material injury to cotton occurs only after. the corn has become too old to furnish suitable food. A consideration of the bollworm on cot- ton, therefore, requires brief mention of its occurrence on corn. The eggs are deposited quite promiscuously over the plant. On young corn the distribution of eggs is confined largely to the leaves, and as many as twenty to twenty-five may often be counted on a sin- gle small plant. On corn in tassel and fresh silk, eggs are deposited quite generally over these parts, and the number which may be depos- ited on a single plant is often surprisingly large. Notwithstanding the large number of eggs which may be deposited on corn, only a small proportion of the larvee from these ever reach full growth. Larvee hatching from eggs laid on other parts of the plant than the silks will mostly perish in their search for suitable food; while, owing to their cannibalistic habits, from the numerous eges deposited by the moths on the fresh silks, not more than two or three larvee will succeed in attaining maturity in the same ear. Corn, in addition to being an excellent trap crop to attract moths away from cotton, also serves to reduce the insects in numbers. ae to young corn by the first generation is confined largely to the ** bud,” and becomes apparent as the more central, ragged, and shot- holed leaves unfold (fig. 3). It is rarely serious in extent. Injury by an allied species, the fall army worm (Laphygma frugiperda 3. & A.) is often very severe on June corn planted in early summev, and has been erroneously attributed to the bollworm. Likewise, injury by the second generation of bollworms is comparatively insignificant, but the third generation, affecting roasting ears, may be the cavse of much loss. Injury is not confined to the quantity of kernels of corn eaten, which in the aggregate must be considerable, but more inzportant dam- age results from the molding and souring of the ear, favored by the filthy excrement and exuded milky juices from the injured grain (fig. 4). No practical means, aside from late fall or winter plowing. have, as yet, been discovered for reducing bollworm injury to corp 191 THE BOLLWORM ON COTTON. an Noticeable injury to cotton usually begins with the August genera- tion of larve. A few bollworms may have been found in cotton — Fig. 3.—Young corn plant showing injury to ‘‘bud”’ by bollworm—natural size (original). earlier in the season, but the amount of injury done by these is of comparatively little importance. 191 11 Eggs are deposited more or less generally over all parts of the plant. The bollworm on hatching will usually at once devour the eggshell from which it has just escaped. If the place of its birth be on a bud, square, or flower, it may soon penetrate within. If on a leaf, stem, or petiole, it soon ) 7 begins to crawl up if I) thf and down, here and s aA Hi there, over the plant, Wf searching for the ten- der buds or squares. Tn the course of this more or less aimless wandering from one leaf or part to an- other, it feeds freely enough to insure its death if poison be present onthe plants. The average distri- bution of eggs over the cotton plants, therefore, has an im- portant bearing on the subject of boll- worm control by the use of poisons. During August, 1903, moths were watched late in the evening while they were Ovipositing on cotton, and an accu- rate record was made of the number and distribution of the eggs placed on the plants. The combined record of the eight moths observed is as follows: Fie. 4.—Roasting ear infested by bollworm—natural size (original). Distribution of bollworm eggs on cotton plants. Eggs deposited on— ; IMCAVES ap PEL SUMACE a5 eee ee nae seen ne eee ere La Le 40 CAVES SOW eT ASUTIACO So... can eye a eee Se eens kG yy) pee tte 44 SISTHAIRES 3 oe Geese oe aU EB Ge SHEE COE De ESOS ae ens 35 JDU GR GSES) Gass See ee Oe RES OS Ae Se St ee TER SS 11 eter GehOlES)ted. Ja30st heen at SL eoeee ee oS ee 11 SICH og AIS OCIA OEE GES OEE AE Ee gee ee eae 15 IBGE 28 BEG aoe Sts oe oO Oe SOE OMB aS Bg ee ET oe er is eae 5 IWicedspmnncoitonvieldiie lc stmmess nee emery e. | . 5 oY CL EN Se 27 Rotalanwnti ber or, plants. Ceposited Ons. =o 32-2 slosh eset ecu. e heck se Stee 63 191 12 This shows that out of a total of 161 eggs placed on the different parts of the cotton plants, 84, or 52 per cent, were deposited on the leaves. The eggs placed on leaves, leaf stalks, stems, and weeds may be considered in practically the same class with respect to the suscep- tibility of the resulting larvee to poisons, and the percentage is thus raised from 52 to approximately 73. The combined result of the examination of eight cotton plants for: bollworm eggs, taken at random in a typical ‘field, is as follows: Distribution of bollworm eggs on plants. Eggs found on— Th@aVGS . 2 352 shee se ee en eee eae ack a eet eee ore 23 Squares. 225.236. Cote eee a Le SE ot. Brea ee ei eee 15 Blowers! Ses 2e6 Ges Cats oaks Sern as 2s Ses ae nee eee Ae 0 Leal stalks) (petioles) ‘so 22h Beni) 235 eee Ss oo eee ee er eee 2 By this method it is shown that approximately 65 per cent of the eggs found on the plants was on other parts than the squares, flowers, and bolls. Fic. 5.—Normal cotton square at left; flared square at right, due to bollworm attack—natural size (original). Bollworm injury to cotton squares is quite characteristic and is not likely to be confused with that of any other insect, except, possibly, with that of Thecla pwas. The injury done by this latter species is, however, comparatively insignificant. The usual effect of bollworm injury on the squares is to cause them to ‘‘ flare” and to drop (fig. 5). But there are other causes which bring about this “ flaring ” and drop- 191 13 ping of the squares, as injury by the boll weevil and the punctures of the sharpshooter and other sucking insects. Under certain climatic conditions, as extremes in rainfall and drought, the plant may of itself throw off a considerable number of squares and young bolls. Much of this shedding, whatever the cause, is attributed by planters to the bollworm, and the insect is thus frequently charged with damage greatly out of proportion to the real injury inflicted. Injury to the boll is likewise easily recognized (figs. 6 and 7). A cir- cular hole is eaten into the boll, usually near its base, of sufficient size to admit the body of the larva. The worm may simply penetrate the boll, leaving it for an- other, or it may eat quite to the interior and devour more or less of the contents. An individual boll- worm may traverse a plant many times in its search for food, or even leave the plant. The traveling may be done during any part of the day, though it is to be noted that the hot sun is avoided as much as_ possible. The amount of dam- age done by a single larva is quite vari- able and hard to de- termine. The worm Fic. 6.—Cotton boll, showing mode of attack by bollworm from with- may find a suitable out—naturai size (original). boll and largely devour it, or a considerable number may be eaten into, one being left for another on account of its hardness or for other rea- sons. When feeding on squares, a large number of these must neces- sarily be devoured, by reason of their small size, to furnish the food required for the larva in its growth. The moths or parents of the bollworm are largely nocturnal in their habits, beginning to feed, and the females to oviposit, about twilight, yet it is to be noted that in times of abundance, as during August, many moths may be seen feeding and ovipositing during almost any part of the day, but especially in the afternoon if the sun be more or 191 14 less clouded. The principal food of the moths in cotton fields is the nectar secreted by the glands at the base of the bracts surrounding the squares and flowers. Many moths are doubtless attracted to cotton fields on account of the abundance of nectar, and we have the unusual condition in Nature of a plant attracting its own worst enemy. It is difficult to deter- mine the number of eggs deposited by a moth un- der normal conditions in the field. In the labora- tory at Victoria moths kept in confinement and fed on sugar water aver- aged about 1,200 eggs each, witha range of from 900 to about 2,200. This is a considerably larger number than has hereto- fore been accredited to this species. Estimating that only 10 per cent of the 1,200 eggs hatch, and that of this number one- half will produce females capable of laying eggs, the progeny of one moth appearing in spring by the fourth, or August, generation would be 25,920 bollworgns, and by September, or the fifth generation, the number would be 155,520. It is thus readily understood how, under favorable conditions, the bollworm may become so numerous and destructive. Fic. 7.—Opened boll to show bollworm at work within—natu- ral size (original). SOME FACTORS WHICH TEND TO KEEP BOLLWORMS REDUCED. Owing to their habits of feeding more or less protected from the attack of parasitic and predaceous insects, bollworms enjoy consider- able freedom from important natural checks. The eggs are freely parasitized by a small hymenopterous insect, during certain periods from 50 to 75 per cent being thus destroyed. The larve are preyed upon by several species of wasps, and also by ants, which do consid- erable good in this way. They are parasitized by certain Tachina flies, and succumb in considerable numbers at times to a bacterial dis- ease. During the spring and fall, when the variation in temperature is greater, many bollworms die of this disease before entering the soil to pupate, or shortly afterwards. 191 15 Under this heading may also be mentioned the cannibalistic habits of the bollworms themselves. Of the many small laryee which may be found in a recently silked ear of corn, rarely more than two or three will escape being devoured by their larger fellows, and succeed in reaching maturity. Weather conditions also exert an important influence on this species. In general, rains late in July and early in August favor bollworm injury. Bollworms, along with insects in general, are food for many species of birds and for barnyard fowls. At Calvert, Tex., the present year a flock of turkeys was observed feeding on bollworms infesting alfalfa. The distended crops of the turkeys of the entire flock gave evidence of the considerable number of larvee which they had eaten during the morning. INEFFECTIVE METHODS OF BOLLWORM CONTROL. During periods. of serious bollworm injury various methods are often resorted to by planters in their efforts to prevent the destruc- tion of the crop. Some of these do little, if any, good and, as a rule, result only in a waste of time and money. Attention is called to the more common of these, in order that this needless loss may not occur in the future. | LIGHTS FOR TRAPPING MOTHS. Various light traps have often been advised, and reports are not wanting as to their efficiency. Nevertheless the careful investigation of this subject by this Division has shown that the use of lights for attracting and destroying bollworm moths is without beneficial results. It is true that bollworm moths have been captured at lights, but these have been few in number and mostly males or worn-out females. Numerous species of moths and other insects may be caught, often in large quantities, by lights placed in cotton fields. A careful exami- nation of the catch, however, will show comparatively few bollworm moths. The other insects caught include many that are beneficial by preying upon injurious species. There can be no doubt that money expended in the use of light traps is entirely lost. POISONED SWEETS. The use of poisoned baits, as vinegar and molasses poisoned with cobalt to attract the moths in feeding, has been more or less recom- mended for many years. The practice has been to pour out the bait on plates, placing them on small stakes set up here and there in the cotton field. Experiments the past year with poisoned baits have given no results of material value in bollworm control, though in times of scarcity of food the moths might be attracted in greater num- bers. On the whole the method has nothing to recommend it. 191 16 BURNING SULPHUR IN COTTON FIELDS. This appears to be a comparatively recent practice. Burning sul- phur is hauled through the cotton fields between the rows on small sleds. Considerable sulphur was used in this way during August of the past year. Its advocates claim that the fumes of the sulphur drive the bollworm moths out of the field. The experiments of the writer with burning sulphur in cotton fields, in 1903, do not indicate any possible benefit from its use. Bollworm and cotton caterpillar moths are often frightened from the plants, but usually fly only a short dis- tance before darting among the plants again. The simple walking between the rows would disturb the millers almost as much, and the recommendation has no valid foundation. RESISTANT VARIETIES. The idea of making a crop of cotton ahead of the bollworm by the early planting of early varieties has, toa limited extent, been confused with the idea of immunity on the part of the varieties recommended. It should be stated that, so far as known, there are no varieties of cotton immune to attack by the bollworm. It will be remembered that, in regard to its feeding habits, this insect is practically omnivo- rous, and it is not likely that it would be deterred by the slight differ- ences occurring in the different varieties of cotton. FIELD EXPERIMENTS IN 1903. The field experiments of the Division of Entomology with the boll- worm during the past season were conducted along the following lines: (1) To determine the possibility of making a crop of cotton before the period of greatest bollworm injury by the early planting of an early-maturing variety of cotton, aided by thorough cultivation. (2) To determine the value in bollworm control of spraying or dust- ing cotton with arsenical poisons. (3) To determine the value of corn as a trap crop in protecting cotton from bollworm injury. Incidentally, tests were made of light traps, poisoned sweets, fumi- gation of fields with sulphur, and methods of similar character. CULTURAL METHODS. The more or less general rains which prevailed in Texas during the winter and early spring of 1902-3 delayed the planting season, which was everywhere from about four to six weeks late, and in this important respect conditions were unfavorable for the experiments involving the early planting of cotton. The accompanying diagram shows the arrangement, treatment of, and yield from the respective plats in the experiment acreage located on the plantation of Capt. B. D. Wilson, at Hetty, Tex. The plats 191 ig were located on fairly uniform rich ‘‘second-bottom” soil, capable of producing during favorable seasons about 1 bale of cotton to the acre. Bollworms had been especially destructive to the cotton grown on this land the year previous. According to Captain Wilson, their injury on the plantation during 1902 was such that from 850 acres planted in cotton only 28 bales were gathered. Experimental cotton plats of the Department of Agriculture at Hetty, Tex., 1903. | Plat 1. 5 acres. King seed. Planted May 1. Thorough cultivation. Yield, 6,741 pounds seed cotton, or 1,348.20 pounds per acre. Plat 2. 5 acres. King seed. Planted May 1. Average cultivation. Yield, 5,020 pounds seed cotton, or 1,004 pounds per acre. Plat 3. 5 acres. King seed. Planted June 1-2. Thorough cultivation. Yield, 1,804 pounds seed cotton, or 360.80 pounds per acre. Plat 4. 5 acres. King seed. Planted June 1-2. Average cultivation. Yield, 1,379 pounds seed cotton, or 275.80 pounds per acre. Plat 5. 5 acres. Gin seed. Planted May 1. Replanted May 20. Thorough cultivation. Yield, 938 pounds seed cotton, or 187.60 pounds per acre. Plat 6. 5 acres. Gin seed. Planted May 1. Replanted May 20. Average cultivation. Yield, 887 pounds seed cotton, or 177.40 pounds per acre. Turn row. Plat 7. 5 acres. Gin seed. Planted June 1-2. Thorough cultivation. Yield, 692 pounds seed cotton, or 138.40 pounds per acre. Plat 8. 5 acres. Gin seed. Planted June 1-2. Average cultivation. Yield, 647 pounds seed cotton, or 129.40 pounds per acre. It will be noted that the scheme includes the comparison of an early- maturing variety of cotton (King) with cotton grown from common 191 8538—No. 191—04——2 18 gin seed; of early and late planting; and of thorough with average cultivation under both of the above conditions. By thorough culti- vation is meant five to six plowings with three or four choppings, and by average cultivation, three to four plowings with two or three chop- pings. The rows were 5 feet apart and the plants were chopped to 30 inches in the row. It was desired to determine by comparison the relation of these several methods of treatment to the production of cotton during a sea- son of severe bollworm injury. Fortunately, from an experimental standpoint, this insect was quite numerous and destructive in these plats, and on the plantation generally, during August and the first half of September, and the results obtained, therefore, bear directly on the question of the possibility of reducing bollworm injury by cultural methods. The considerable difference in yield to be noted between the King plats and the plats planted to common gin seed must, in fairness, be attributed in part to the abnormal lateness of the season. While a full growing and fruiting season was afforded the early-maturing © variety, the later common gin seed cotton was cut off by frost. The latter, with an average season, would no doubt have matured a con- siderably larger crop. In the comparisons between plats 1 and 5 and between plats 2 and 6 it should be noted that plats 5 and 6 were entirely replanted twenty days later than date of first planting, so that these plats were in fact planted rather late instead of early. But the necessity for replanting was due entirely to the inferiority of the common gin seed to the King seed. The superior vitality of the King seed resulted in a satisfactory stand under the adverse weather conditions then prevailing, whereas the gin seed germinated very poorly. The results are in full accord with the observations made on the respective plats throughout the season. Plats 1 and 2 suffered much less from bollworms during August and September by reason of their more matured condition than did the other plats. The injury was most marked on the late fruiting and comparatively unprolific plants from native gin seed, and a considerable part of the reduction in yield must be attributed to this fact. For ready comparison the more important results of the experi- ments at Hetty are shown in the following statements: Early-maturing variety versus native gin seed. Yield per acre with early-planted King seed and thorough cultivation, pounds seed cotton’ Le! Lota. 22 ante Bes. chk) Soe 1, 348. 20 Yield per acre with early-planted native gin seed and thorough cultivation, pounds seed cotton... < 22.2 22-soe Je note -2 Ses ee eee Sein 187. 60 Yield per acre in favor of King seed --.-...-...----- pounds seed cotton-. 1, 160. 60 Value of excess per acre, at 3 cents per pound of seed cotton --_---.------ $34. 81 191 19 Early-planted King seed, with thorough cultivation versus late-planted native gin seed with average cultivation. Yield per acre with early-planted King seed and thorough cultivation, “RTS SCE SU TSO FG Se en ee Pe oy ee re eee has eee ee ae 1, 348. 20 Yield per acre with late-planted native gin seed and average cultivation, PENH HUCEM EMT DOM oe se eo aga =o o6 Ho seen a ee 129. 40 Yield per acre in favor of early-planted King seed with thorough COllbin an OMes =e hens oe ree. fe eS pounds seed cotton.. 1, 218. 80 Value of excess per acre, at 3 cents per pound of seed cotton.-_.-.......- $36. 56 Early planting with thorough cultivation versus late planting with thorough cultivation. Yield per-acre with early-planted King seed and thorough cultivation, Seqmercs Poeeremuuiine. 22.9.0 #1003 Saiiih ibe SLU el oes tee 1, 348. 20 Yield per acre with late-planted King seed and thorough cultivation, PERILS SSS B31 cpg Ag ec gat Aa tae a ee 360. 80 Yield per acre in favor of early planting. - sees pounds seed cotton.. 987. 40 Value per acre in favor of early planting, at 3 cents per pound of seed eqtton== 2. = ee te er ee eat See ee he a oe ae $29. 62 Thorough cultivation versus average cultivation. Yield per acre with early-planted King seed and thorough cultivation, Penne CREM aA oa s Cae eld Coa oa Se Wants oc te noet eee 1, 348. 20 Yield per acre with early-planted ee seed and average cultivation, rmrMeS SDECE MUNIN. PEL Uo. he ane e os Ee aly Sod 1, 004. 00 Yield per acre in favor of thorough cultivation..pounds seed cotton.. 344. 20 Value of excess per acre, at 3 cents per pound of seed cotton --......----- $10. 32 Early planting with thorough cultivation versus late planting with average cultivation. Yield per acre with early-planted King’seed and thorough cultivation, PR CRAB? ears se A eS cle oe Se ES eA oe Nee ee 1, 348. 20 Yield per acre with late-planted King seed and average cultivation, THAT ISeCe COLON. as — he Setar wo tee kek see She ee ke ate ek 275. 80 Yield per acre in favor early planting and thorough cultivation, OUNUCISeCUy COLLOM as sae ear a aes ete Qa ee eee eee ee 1, 072. 40 _ Walue of excess, at 3 cents per pound of seed cotton..........------------ $32. 17 ARSENICAL POISONS. Although poisons have long been recommended for bollworm con- trol on cotton, their use has not been adopted to any extent. This may have been due to the fact that their value in this particular had not been demonstrated in any such way as to furnish tangible results. The possible usefulness of poisons is based on facts connected with the early life of the bollworm, not ordinarily taken into consideration by planters. Bollworms are not usually noticed until they have begun to bore into the squares, flowers, and bolls, and the application of Been be at this time manifestly appears to be of little use. It has already been shown (page 14) that from 65 to 73 per cent of the eggs deposited by bollworm moths on the cotton plant, are so 191 20 placed that the resulting larva would be more or less subject to poison- ing, if poisons were present on the plants. As bearing on this point the following experiments are of interest: During June, a cotton plant bearing numerous squares, flowers, and bolls, was sprayed with Paris green at the rate of 1 pound to 100 gallons of water. A few hours later 100 larve, just hatched, were distributed over the plant, which was then covered with a large wire- screen cage for protection. Subsequent examinations did not reveal any bollworms whatever on the plant, the larve doubtless being all destroyed by the poison. A similar test was made during August, but only 50 young larve were used. Outof this number but one bollworm survived, which was found when about two weeks old feeding on a half-grown boll. Field experiments with poison were conducted at Hetty and at Cal- vert, Tex., and, although started somewhat late, nevertheless gave decidedly favorable results. At Hetty, a 10-acre cut of uniform, late, native cotton, growing on bottom land, was selected, 5 acres of which was poisoned and 5 acres was left unpoisoned, as a basis for comparison. Paris green was dusted freely over the plants by the usual dusting method, namely, from bags on the ends of a short pole carried by a man on horseback. Applications were made August 22 and 31 and September 8, using approximately 3 pounds of the ‘‘green” per acre at each dusting. The results are indicated in the following table: Comparison of yields from plat dusted with Paris green and plat left untreated. Yield from poisoned S-aere plato... .. 222025252... c2ee pounds seed cotton... 2, 720 Wield from unpoisoned:5-2cre iplates=2= 2-2 -ss— se eee eee eee doz... Wj434 Yield in favor of poisoning. .-.+22--222-c2ctceece tees eee ee Cowke 1286 Value of excess, at 3 cents per pound of seed cotton.--.....-..-..-2--2----- $38. 58 Cost of 45 pounds of Paris green, at 18 cents per pound -.....--.-.--------- $8. 10 Cost of labor, one man three mornings, at 50 cents per morning ------------ 1.50 Total cost of poisoning se! s-.-— 22-0 soe eee eee eee eee eee 9. 60 Net @ain per Sere in favor:ol poisoning: -. ....:o2 obese fe ee ees 5. 79 At Calvert poisons were applied by the dusting method and also by means of a spray pump. The spraying was done with a barrel sprayer furnished with two leads of hose and four nozzles. A team, wagon, and two men were required, one man to drive and pump, the other to handle the nozzles at the rear end of the wagon. ‘‘ Green arsenoid” was used, at the rate of 1 pound to 50 gallons of water, which would poison approximately 1 acre. With water one-half mile distant, only 5 to 6 acres per day could be sprayed. With a more convenient water supply and with geared spraying machinery, the ground covered per 191 : 21 day, could, no doubt, be considerably increased. Below is the treat- ment given and the results from the respective plats: Comparison of yields from plat sprayed with “green arsenoid,’’ plat dusted with Paris green, and plat left untreated. Plat I, 3.89 acres, left untreated for comparison; yield of seed cotton per EXER ah haa Eh ee gal ee ni pounds.. 246.0 Plat II, 4.37 acres, treated with ‘‘green arsenoid,”’ 1 pound to 50 gallons water; ' sprayed August 14, 28, and September 5; yield of seed cotton per acre, penton Sr ho ok Sas ened shone oe aan esdan Bap oa 554. & Increased yield of seed cotton per acre in favor of spraying..pounds.. 308.8 Value of gain per acre, at 3 cents per pound of seed cotton ...........------ $9. 26 Cost of three sprayings per acre, including labor and poisons...--..-.------ 22 Netagim per acre in. favor of spraying. .-3..-- 22.52 43-.42--52.563-2- 6. 99 Plat III, 4.38 acres, dusted with Paris green, average of 3 pounds per acre; poisoned August 15, 22, and September 4; yield of seed cotton per acre, RLGHIETOGL Steere et anet: ete abe teeny cee Lge, 8 te ee Se sO SE ee a ee 460. 21 Increased yield of seed cotton per acre from poisoning ------------ pounds.- 214, 21 ‘Value of increase per acre, at 3 cents per pound of seed cotton _.....------- $6. 42 Cost of three dustings per acre, including labor and poisons....-..--..----- 1.98 Neu calmoner acre ToOnt POIsOHINe. = 212259 o0 52 se sa oun Fao een k 4, 44 CORN AS A TRAP CROP. Attention has already been called to the fact that corn, when in a suitable condition, is the preferred food of the bollworm, and that cotton is not materially injured until after the corn has begun to harden. It would therefore appear that bollworms might be largely kept out of cotton by the proper use of corn as a trap crop. The use of corn in this way has been frequently recommended by this Division, and instances are not wanting where good results have been secured. Nevertheless, for reasons not apparent, this expedient has been but little adopted. Extensive tests of corn as a trap crop in protecting cotton from bollworm injury were made the past year, both at Calvert and at Willspoint, Tex. Unfavorable weather and soil conditions, however, necessitated considerable change in the original plans, and it was pos- sible to have corn in silk for the August generation only. But it is usually this generation that causes the greatest injury to cotton, and the control of which is especially important. It is not permitted, as in the experiments previously reported, to indicate the value of the trap crop in pounds of seed cotton, as it is manifestly impossible to arrange a control plat which would meet the necessary condition of adjacent location to the plat under test, and at the same time be entirely free from the protective influence of the corn. Bollworm moths fiy about freely in the cotton fields and would be attracted a considerable 191 22 distance by the trap crop. Its value, in fact, depends to a considerable extent on this migratory habit of the moths. The experiments in question, as finally arranged, provided for belts of corn around and through the cotton fields, planted so as to be in prime silking condition about August 1. By this means, the large generation of moths appearing in late July and August, from larve infesting roasting ears in the surrounding cornfields, was largely detracted from the cotton, and egg-laying was concentrated on the trap rows of corn. The number of eggs found on a single corn plant was often surprisingly great. Thus, in the trap rows at Willspoint during early August, when the moths were out in large numbers, 804 bollworm eggs were counted on a single corn plant, and the average of eight typical plants at this time was 495 per plant, distributed as follows: 175 on the leaves, 45 on the leaf sheaths, 120 on the tassels, and 155 onthesilks. Furthermore, the trap rows of corn were attract- ive to the moths all through the season, from the time the plants were from 12 to 18 inches high until ripening began. The total number of eggs deposited on a plant during its entire period of growth must be very great, and a simple calculation will indicate the enormous number of bollworm eggs that are kept from cotton by a series of belts of corn planted through the cotton field. It might be supposed that, by thus furnishing the insect with its favorite food, its increase and consequent greater destructiveness would be the result. This, however, is not the case. From the sey- eral hundred eggs that may be found ona single corn plant but two or three larve will eventually succeed in attaining their growth, owing to the cannibalistic habits of the larve themselves, and for other reasons already pointed out. SPECIFIC RECOMMENDATIONS. The earlier investigations of the Division of Entomology and its work the past season warrant the recommendation of the following methods of lessening bollworm injury: J. Plant an early maturing variety of cotton as early as possible in the spring and give the plants good cultivation. By good cultivation is meant five or six plowings, with three or four choppings. By plowing and cultivating in this way a good crop may usually be insured before the bollworms become destructive in August. Inthe territory infested with the cotton boll weevil this course becomes doubly necessary, as it is only by such methods that ordinarily a crop of cotton may be made. The possibility of the plants developing a crop after the bollworms may leave is removed on account of the presence of the weevil. Early plant- ing of early maturing varieties will also allow of the crop being gathered much earlier in the fall than is possible with plantings of ordinary gin seed at the usual time. It will thus become possible to a considerable 191 23 extent to clear the land of the plants and plow in the fall, which, aside from being good farm practice, will exert a very beneficial influence in controlling the bollworm by breaking open their hibernation cells and exposing the pupe to the influences of cold and rain during the winter. The above recommendations involve no outlay of labor and capital not requisite to successful cotton culture, and, furthermore, agree entirely with the best known methods of circumventing the ravages of the Mexican cotton boll weevil. It thus becomes possible to secure the maximum amount of freedom from the depredations of the boll weevil and the bollworm by one and the same course of farm practice. II. The use of corn as a trap crop may be advantageously combined with the cultural methods indicated above, especially so if it is not found possible to plant early on account of climatic conditions or for other reasons. In planting cotton leave vacant strips across the field every 200 or 300 feet, sufficiently wide for planting 10 or 12 rows of corn. These strips should be planted with corn so that it will be in prime silking condition not later than August 1. Under favorable conditions of rainfall and with good cultivation, Mexican June corn planted by June 1 will be tasseling and silking freely by August 1. Plant cowpeas in the corn belts, so that the plants will be flowering along - with the appearance of the tassels and silks on the corn. The cowpeas are to furnish food for the moths and will largely prevent their going to the cotton for food and depositing thereon a certain proportion of their eggs. The corn may be allowed to mature and may be harvested in the usual way. Sufficient corn may be grown in these belts to meet a portion of the needs of the plantation and at the same time afford material protection to the cotton crop from bollworms. As will at once appear, the planting of corn through the cotton field at the usual time in the spring is bad practice from a bollworm point of view. With the hardening of the corn during July the insects turn their attention to cotton. The trap rows of corn should not be tasseling and silking before about August 1. II. Experiments with poisons the past year indicate that these may be profitably used in lessening bollworm injury to cotton. The poisons should be applied to the plants in time to insure the destruc- tion of the maximum number of young larve of the August genera- tion. In general, this will be about August 1. When it is noticed that the moths are becoming abundant in the cotton fields the first application should be made, and a second application should follow a week or ten days later. The occurrence of even a moderate rain shortly after the poison has been applied will necessitate another application if best results are to be secured. If conditions are favor- able for bollworm injury poison should be used again about Septembe:: 1 in time to check injury from the September generation of larve. In the work of poisoning special pains should be taken to cover all parts 191 24 of the plant as nearly as possible. The poisons should be distributed much more generally over the plant than is necessary for the cotton caterpillar. Of the modes of applying the poison little need be said. The gen-. eral use of poisons against the cotton caterpillar has familiarized most planters with the details of this work. In point of convenience the dusting method is to be recommended. If an abundance of water is at hand, suitable spraying machinery may be used. The amount of poison used in the dusting method will be greater than that required to poison an equal area by spraying, but in dusting there will bea saving in labor and machinery, and what is more important, the work may be done-more rapidly. The question of how to apply the poisons most economically, and in a way to secure the best results, should be settled by each planter according to his conditions. If the work be done with spraying machinery, a poison, such as Paris green, should be used at the rate of 1 pound to every 50 gallons of water, and if the dusting method is adopted, from 2 to 3 pounds will be required per acre for each application. In conclusion, attention should be called to the entire practica- bility of the methods recommended. They may be used singly, or any two may be employed, as the early planting of early varieties, supple- mented by the use of poisons or trap crops; or all three may be employed in conjunction, and, if properly managed, should give a large degree of freedom from bollworm injury. 191 O Vv ‘ U. S. DEPARTMENT OF AGRICULTURE. FARMERS’ BULLETIN No. 196. USEFULNESS OF THE AMERICAN TOAD. BY A. H. KIRKLAND, M. S. WASHINGTON : GOVERNMENT PRINTING OFFICE 1904. LETTER OF TRANSMITTAL, Unirep Srates DreparrMenT or AGRICULTURE, Drvision or Enromooey, Washington, D. C., April 22, 1904. Dear Str: I submit herewith a short paper on The Usefulness of the American Toad, prepared by A. H. Kirkland, M. 8., of Boston, Mass., an entomologist and writer on entomological subjects. Mr. Kirkland has made a somewhat thorough and extended study of the toad as a destroyer of insects, arriving at the conclusion that this little animal is a valuable friend to all who are engaged in agriculture, and supporting this conclusion with evidence derived from his investigations. In the hope that the toad’s life history and habits may be better understood, its usefulness more fully appreciated, and its protection from wanton destruction secured, it is recommended that this paper be published as a Farmers’ Bulletin. Respectfull 4 i L. O. Howarp, Entomologist. Hon. JamrEs WILSON, Secretary of Agriculture. CONTENTS. Page. UMtroOdUction ios Soames bce eee MA. ones eee ence oes 14 How the toad may be madeiselaliseotees See eee... - cen nce conan 14 The study of the toad ....scssccnecumuabeens =< BEE Suton wasacnsakwaamapess 15 2 196 USEFULNESS OF THE AMERICAN TOAD. INTRODUCTION. The heavy tax levied by insects on nearly all agricultural crops is well known to farmers. Nearly as well known, thanks to Experiment Station experts and others, are the principal remedies for combating these pests. But in the long run nature provides the most efficient checks on insect increase and these often are but little understood or appreciated. While the value of, birds as destroyers of noxious insects is now becoming generally recognized, the silent, inconspicuous work of insect parasites and certain predaceous animals receives but slight recognition even from those who are most directly benefited. Thus the common toad,“ nocturnal, of quiet habit and appearance, renders notable service to farmers and gardeners throughout the entire growing season; yet to many its worth is unknown, while to others it is even an object of disgust, if not of fear. It must be admitted that to some the toad can never be anattractive animal. Nature bas denied it the gay colors of bird life or even the sinuous beauty of some of its reptilian relatives. Yet, judged by the standard of good works, the toad does not suffer by comparison with any of the lower animals. The toad has always borne the burden of false and even ludicrous misrepresentations. We have adopted in their entirety the principal European traditions concerning the toad as set forth by the early writers on natural history. These ancient savants, who did so much to establish the study of nature, had the failing, not confined to that age, of confounding fancy with fact. Thus the popular superstitions of that time are curiously interwoven with their statements concerning the life history and habits of the toad. The early writings on this subject teem with vague and ludicrous fancies of the toad’s ven- omous qualities, its medicinal virtues, and more commonly of the val- uable toadstone or jewel to be found in its head. All these tradi- tions are to be met with even in this era of progress, and coupled with them we hear of the equally surprising ability of the toad to produce @ The information given in this bulletin relates chiefly to our common eastern toad (Bufo lentiginosus americanus Le C.). Other species have similar habits where the samec lagses of insects are available for food.—Epiror. 196 4 warts on the hands; to poison infants by its breath; to bring good for- tune to the house in whose new-made cellar it takes up its abode; and, finally, to cause bloody milk in cows if killed by accident or design. The writer well recalls the shock his credulity received when in the inquisitive stage of boyhood he faithfully tested several of these super- stitions with only negative results. When so much that is false has been written about the toad it may not be amiss to increase the scanty literature of facts concerning this humble servant of man as deter- mined by a somewhat intimate acquaintance extending over a decade or more. LIFE HISTORY AND HABITS. To the nature lover there are few more interesting subjects than the development and habits of the toad. In New England toads do not bestir themselves until April or May, but in more southern lati- tudes March finds them wakening from their winter’s sleep and begin- ning their annual migration toward the breeding ponds, where a little later is heard the soft, drowsy, musical trilling of the males, so well described by Gibson as the ‘‘ sweetest sound in nature.” The number of toads which migrate even to a small pond is remarkable. The writer once counted 356 toads on the shores of a pond containing scarcely half an acre. Mating is commenced as soon as the water is reached, or even before. The tiny black eggs, with their gelatinous covering, are laid in long ‘‘ ropes,” the envelope swelling to a notable degree as soon as it comes in contact with the water, thus forming a mass many times larger than the body of the parent toad. In two weeks, or even sooner if the water be warm, the eggs hatch and the young tadpoles feed greedily upon the gelatinous envelope. Next the slimy deposits common to ponds are attacked. The tadpoles grow rapidly, until by June or July the legs develop, the tail is absorbed, and the young toads leave the pond which has sheltered them, never to return except for brief visits at the mating season. The little toads are very sensitive to heat and secrete themselves under leaves, rubbish, stones, etc., during the day; but let a vigorous shower descend and frequently walks, roads, and gardens at once become peopled with these thirsty leaping creatures. So sudden is their appearance under these conditions as to lead to the popular belief that they rain down. The inability of toads to endure heat serves as an indirect protection for them at this stage. They are delectable morsels to many birds, and, were it not for the fact that they are obliged to seek shelter by day, large numbers would be destroyed. As it is, many are devoured by the predaceous birds and mammals which prowl at night. It seems probable that the toad does not begin to reproduce until the fourth year. The number of eggs laid by a full-grown female 196 5 toad is remarkable. It is a rule of nature that where the chance for a species reaching maturity is small the fecundity is large, and this rule is well illustrated in the case of the animal under discussion. The writer once removed 1,279 eggs from a female toad which had already commenced laying. The total egg production is better indicated by the record of 7,587 and‘11,545 eggs obtained from two toads by Dr. C. F. Hodge, Clark University, Worcester, Mass., as recorded in his book entitled ‘‘ Nature Study and Life.” Many stories are extant concerning the longevity of the toad. These animals are said to have been found embedded in rocks, trees, masonry, etc., thus indicating that it was possible for them to exist in dormant condition for many years. The writer has gone to some trouble to_ investigate statements of this kind coming to his attention without finding a single case where there was conclusive evidence of such a prolonged dormant state. On the other hand, we have the experiment of M. Herrisant, who in 1777 embedded three toads in plaster and placed them in the archives of the French Academy of Sciences. At the end of eighteen months two of the toads were still alive. In 1817 Doctor Edwards repeated this experiment, but submerged the plaster blocks in water, with the result that all of the toads died. Buckland buried toads in cavities in sandstone and limestone and found that all the toads in sandstone were dead in thirteen months, while those in limestone survived for nearly two years. The toad has a strong ‘‘ homing” instinct, and lives year after year in the same locality. Convincing evidence has been furnished the writer of two toads that have occupied dooryards in two different towns for twelve and twenty-three years, respectively, while Mr. F. H. Mosher, Westport, Mass., has positive knowledge of a toad which occupied a certain feeding ground for at least eight years. In view of these facts, there can be little doubt that the toad attains to a con- siderable age. The belief that the toad is venomous probably arises from its habit, when disturbed or roughly handled, of ejecting through the skin a certain milky acrid fluid. No harm attends contact with the fluid on the hands, but dogs attempting to bite toads show signs of discomfort, and even distress, due to this acrid skin secretion. That the fiuid is not objectionable to all animals is shown by the avidity with which certain hawks and owls capture and eat toads. It is not uncommon to find during the summer certain toads of much brighter colors than their fellows. This is due to the casting or molt- ing of the skin, which takes place several times annually. Previous to molting, the toad seeks shelter and remains quiet for some time. The skin then splits, peels off, or is removed by aid of the forelegs, and is often eaten by the toad, which soon goes forth clad in fresher colors. 196 6 Though living alone through the summer, it is not an uncommon thing to find a dozen or more toads hibernating in a colony under some convenient rock or board. Winter quarters are sought quite early in the fall beneath rocks, leaves, or rubbish, or in other places where the action of the frost will not be severely felt. Figuier states that these animals freeze without being killed, and it is not unusual to find toads in winter apparently frozen stiff some distance below the surface of the soil. FEEDING HABITS. Soon after sundown, or even before on cool evenings, the toad .emerges from its shelter and sallies forth in search of food. In country districts it nightly patrols over roadsides, gardens, cultivated and new-mown fields—in short, all places where insect life abounds and long grass or herbage does not obstruct its travel. In cities and villages the spots beneath electric lights are particularly favored, while lawns and walks also receive attention. The toad has learned that electric and otherdights attract large numbers of flying insects, many of which fall injured to the ground below. At Amherst, Mass., the writer once observed eight well-fed toads holding festival beneath an are light. During the flying season of the brown-tail moth in Massachusetts there is no more common night scene than that of the toads devouring the white moths which fall fluttering from the lamps above. For two successive summers the writer had opportunity to make numerous observations on toads feeding under natural conditions at all hours of the night. From these observations and from stomach examinations it was apparent that the toad feeds continuously through- out the night, except when its food supply is unusually abundant, when periods of feeding and resting alternate. From such observa- tions, as well as by studying toads confined in cages, it was found that in twenty-four hours the toad consumed a quantity of insect food equal to about four times its stomach capacity. In other words, the toad’s stomach is practically filled and emptied four times in each twenty-four hours. Dead or motionless food has little attraction for the toad. Only living and moving insects, centipedes, etc., are devoured. Cutworms, for example, are safe while they remain curled up, but let them com- mence crawling and they are soon snapped up by the toad. At first thought it strikes one as odd that the toad’s tongue is attached in front and free behind, particularly as the tongue is its only means for cap- turing food. However, one needs only to watch the feeding of a toad for a few minutes to satisfy himself that this organ is well adapted to its work. The tongue is coated with a glutinous secretion and adheres firmly to the food it seizes. When the writer first took up the study 196 7 of the toad he confined a large specimen in a well-shaded box out of doors. So ravenous was its appetite that to provide sufficient insect food was quite a task until a satisfactory expedient suggested itself. When a hard bread crust was soaked in molasses and placed in the cage it attracted a sufficient number of flies, bees, ants, beetles, etc., to keep the toad well supplied with food. The toad would sit motion- less beside the bread crust until a moving insect came within range, when its tongue would be thrown out with lightning-like rapidity and the insect, often on the wing, would suddenly disappear within the toad. The diet of this toad was varied with occasional fish worms, which, being too large to swallow at once, were forced down the gullet by means of the fore limbs. THE FOOD OF THE TOAD. As pointed out previously, the toad is of direct service to man by reason of the noxious insects which it destroys. Should it feed on beneficial insects, it would be to that extent an injurious animal. There is only one way to determine accurately to what extent an insectivo- rous animal is beneficial or injurious, and that is by a careful examina- tion of the contents of a sufficiently large number of stomachs collected at different dates and over a suitable range of territory. While field observations furnish important circumstantial evidence and aid to an understanding of the kind and condition of food found, the stomach examinations, as Prof. F. E. L. Beal has so aptly put it, ‘‘ constitute the court of final appeal.” Patience, strategy, and good eyesight will enable one to study the feeding habits of such animals, but the absolute identification of the kind and quantity of their food can not be made at long range. For accurate results the material devoured must be available for careful analysis, often under a microscope. The writer a few years ago collected and examined 149 toads’ stomachs, particular effort being made to secure representatives from different sections and from a wide range of places, i. e., gardens, fields, hills, woodlands, city streets, ete., during every month of the feeding season. This number is doubtless too small to show the exact status of the toad in the region covered, yet it is sufficient to afford interesting data for some general conclusions. With the exception of a few stomachs preserved in formalin, all were examined while fresh, the stomachs being split along the outer curvature and the contents care- fully washed into a glass dish. The material thus obtained was sepa- rated into its proper groups, identified, and its percentage of the entire bulk estimated and noted. The number of stomachs examined, by months, was as follows: April, 7; May, 30; June, 66; July, 29; August, 10; September, 7; total, 149. 196 8 Stomach contents of 149 toads, with percentage, by bulk, of each food element. Part, by Part, b Food elements. buik. Food elements. pai Per cent. Per cent. aoe, PTeTTT Te Boose seeeccsesencaescccne 19 Spiders oe eae amen e ee amencesescccnaccess 2 GUILWOLKIS .--- +f ccse ce seccctensesresnune 16 W=DULS « «cc cccateaecdce cpuceanaccanen 2 iehoawand: dosed Wortns +. § coca 2h Jeane 10 || Potato eee and allies: .>.4..3.25252: 1 Tent Caterpillars’. --..cccescenccecmesnee 9") Carrion DeCiies.....c--scccmestsseecscen i Ground beetles and allies............... 8 Mia dlennetas | beetless2sc23. £2). eas 1 May beetlesand allies..................- Gi SHAE Sek tne aces aceeccerere st eseee i Wireworm beetles and allies............ By) Anpleworms::<) .f:beceors seb ecepede ce i WECVislceceseta cess nencecetcosacusuet ane 5 Vegetable d erie eSa'elate Sbalenceeamonee 1 Miscellaneous caterpillars.........-..... 3 Velieceue. ict tu eek . secu tase ease 1 Grasshoppers, crickets. ...........---se- 3 Unidentified animal matter ........... 5 This table shows that at least 98 per cent of the toad’s food is of animal origin. The vegetable matter (1 per cent) was composed of bits of grass, leaves, rotten wood, etc., evidently swept in by accident along with the insect food. It is in this way, doubtless, that gravel (1 per cent) found its way into the stomachs. The unidentified material consisted of broken parts of insects, animal tissue, etc., which were so finely ground as to be beyond recognition and probably repre- sented injurious species in great part, although not so considered in the table. The nature of the vegetable and mineral matter found in the stom- achs needs no further mention. The animal matter recognized con- stitutes 93 per cent of the total food, of which 77 per cent was insects and 16 per cent other forms. As might be expected, nearly all the animal matter is composed of terrestrial species or of forms which at some time frequent the ground for shelter or migration. Worms.—The common angleworm was present in 14 stomachs, prin- cipally in toads taken soon after showers, and formed 1 per cent of the total food. Rains drive the worms to the surface, where they fall easy victims toa particularly hungry toad. From studying toads in con- finement, it appears that worms are not preferred by that animal as an article of diet, but may be eaten. Worms are of great service in tilling and aerating the soil, as Darwin has so well shown. On the other hand, they often cause great annoyance in greenhouses and in flower beds out of doors. Since the toad frequents the abodes of man, it seems probable that the good done by worms in such localities may well be offset by their damage as above mentioned. Snails.—Snails are a serious pest in greenhouses and gardens, where their depredations on lettuce and other succulent plants are well known. Several of the large naked snails common in gardens were found in the stomachs, while, in the case of the shell-bearing snails, it was found that the acid stomach juices of the toad were sufficient to dissolve the shell in a short time. It seems a little strange that such slow-moving animals should attract the attention of the toad, yet it is apparent that the animal finds them suitable articles of food, as shown by their constituting 1 per cent of the total stomach contents. 196 9 Sow bugs.—These small creatures were most numerous in stomachs taken in the late summer, and made up 2 per cent of the food for the season. Their damage to the roots of orchids, violets, pansies, roses, etc., has been frequently noted by florists. By dattaabine them the toad renders a distinct service. Thousand-legged worms.—These form a constant article of diet, as many as 77 having been found in a stomach. Ten per cent of the food of the toad was of this class. They are frequently called ‘‘ wire- worms,” although this name belongs properly to the young of the ‘click beetles.” Farmers often find the attacks of these myriapods on potatoes a serious matter. The late Dr. J. A. Lintner has re- corded an instance where for two years in succession a potato crop was severely injured by these ‘‘worms.” Many cases of injury to newly planted potatoes have come to the writer’s attention, while others have recorded the partial destruction of cucumbers, tomatoes, etc., from this cause. Spiders.—It is not strange that such active creatures as spiders form 2 per cent of the toad’s food. Naturally most of the spiders were of terrestrial species. How much good spiders accomplish is an open question, but since they destroy large numbers of flies we have included them in the column of beneficial insects. It should be noted, however, that the spider’s web often catches those active parasitic flies which would otherwise serve man through the destruction of injurious cater- pillars. Perhaps a fair statement would be that the harm the toad may do by including 2 per cent of spiders in its menu is offset by the 13 per cent of snails, sow bugs, and ‘‘ thousand legs” which it destroys. This brings us, then, with a clean balance sheet to a consideration of its insect food in the strict sense of the term. Grasshoppers, crickets, etec.—These insects were found to make up 3 per cent of the food of the toad, and included several of the common species of the hay field as well as house crickets, tree crickets, and cockroaches. The damage to grass and grain crops by grasshoppers is too well known to require more than mere mention. The black house cricket is often a nuisance, while the cockroaches and water bugs are even worse. The small roach or water bug was often found in stomachs of toads taken on city streets. The toad is entitled to unstinted praise for its work in destroying these insects. Ants.— We come on debatable ground when we take up the economic importance of ants. The writer for the purposes of this paper has regarded them as of neutral value. Most entomological writers regard lightly the shortcomings of these industrious and highly intelligent creatures. Certainly one can not observe their systematic domestic arrangements and evident reasoning powers without a feeling of sincere admiration. During the season of their activities they destroy a cer- tain number of soft-bodied insects and carry off more dead ones as a 196 10 provision against future need. On the other hand, they care for and distribute plant lice and certain other related insects, infest lawns, walks, and dwellings, attack cooked food, and often make of themselves an unmitigated nuisance, as many a perplexed housekeeper can attest. Ants constituted 19 per cent of the total contents of the stomachs examined. The greatest number was found in the May examinations, when they were present in 70 per cent of the stomachs and formed 23 per cent of the food for that month. Aside from ants a few allied insects—such as bumble bees, honey bees, wasps, and hornets—and two ichneumon flies were noted in the examinations. The latter insects are beneficial as parasites on certain caterpillars. Beekeepers have informed the writer of cases where toads had taken position at the entrance of hives, and thus destroyed a large number of bees. This loss might have been avoided by raising the hives above the sur- face of the ground. Since the toads feed principally at night, such cases are probably of rare occurrence. Beetles.—There is a certain family of active black or metallic ground beetles, which are usually present in gardens, fields, or woodlands, feeding for the most part on soft-bodied insects, and occasionally varying their diet by attacking low-growing fruits. These ground beetles undoubtedly are beneficial, as a whole, although the damage to strawberries by certain species has caused considerable loss at times. The most serious charge to be laid against the toad is the destruction of these ground beetles, which make up 8 per cent of the total food. On the other hand, the members of the May-beetle and click-beetle families are commonly present, and furnish 6 and 5 per cent, respec- tively. The May beetle, or June bug, is unfavorably known as the parent of the white grub, which, in certain years, destroys large areas of grass land and lawns, and also works havoc on the potato crop. Promiscuous shooting of crows has removed one of the principal checks on this insect; hence the service of the toad in this connection is of especial value. The ‘‘rose bug,” or rose-chafer, was found in several stomachs. The common wireworms, which attack newly planted corn, are the progeny of the click-beetles, and these insects were present in large numbers in the stomachs examined. Wireworms also attack potatoes, lettuce, cabbage, and other garden crops. Snout-beetles, or weevils, make up 5 per cent of the toad’s food. These insects, of which the plum curculio is a good type, are among the most difficult pests to combat. Nearly all have the habit of drop- ping to the ground and feigning death when disturbed, thus giving the toad a chance to capture them. Among the species found in the stomachs were two specimens of the plum curculio, and many which bore in standing timber and shade trees. Potato bugs, cucumber beetles, and their allies amounted to 1 per 196 11 / cent of the total food. The injurious habits of these species need no comment. Of equal rank were the carrion beetles (1 per cent) of pos- sibly beneficial habits, and miscellaneous beetles (1 per cent). The latter, aside from an occasional ladybug (beneficial), are of no special importance. The sole value of the carrion beetles lies in their habit, of burying or devouring dead animal matter which might otherwise become offensive. Cutworms and army worms.—The young or larve of moths formed 28 per cent of the total food; cutworms forming 16 per cent, tent caterpillars 9 per cent, and miscellaneous caterpillars 3 per cent. The destruction of cutworms is of special importance. These insects feed by night, and the grower only learns of their presence through the loss of his lettuce, cabbage, and other plants. Hand labor offers the most practical remedy, and this is ably assisted by the efforts of the toad. To appreciate fully the number of cutworms a full-grown toad may consume, one should watch these animals in a field infested by army worms, which are members of the cutworm family. Three toads taken under such conditions contained, respectively, 9, 11, and 55army worms. These soft-bodied insects are quickly digested, and the toad’s capacity for cutworms seems only limited by the supply. Tent caterpillars.—The insects consumed by the toad are chiefly those of terrestrial habit. Yet the good work of the toad is not confined to insects of this class. There are a large number of caterpillars which feed ordinarily on trees, yet seek the ground when ready to transform, and these fall easy victims to the toad. The common tent caterpillar of the wild cherry and apple well illustrates this point. These cater- pillars when full grown often travel considerable distances in search of suitable places for cocoon making. In May these insects formed 18 per cent of the food, and for the season 9 per cent. This insect isa pest of the first rank on apple trees and occasionally works on cherry, plum, and peach. It ismuch preyed upon by the cuckoo and oriole, while the toad secures a fair proportion of those that escape the birds. From 15 to 20 were often found in the stomachs, 37 being the largest number noted. The writer once saw a black-billed cuckoo eat 35 of these insects at one meal. That bird is well protected by wise laws. The toad has equally as good a record, but receives no legal protection from wanton cruelty. Miscellaneous caterpillars. —Among these insects, which formed 3 per cent of the food, were noted such injurious species as the gypsy moth, canker-worm, eee grape and celery caterpillars, tomato worms, cabbage worms, etc. Anabundance of active gypsy-moth pet eillwes in certain Mamachisetts localities often proves sufficient to tempt the toad from retirement even at midday. Three of the toads’ stomachs examined contained, respectively, 7, 15, and 65 gypsy caterpillars. As a means of checking the increase of such a serious pest the value of 196 12 the toad is small, but the case is of interest as showing that tree- infesting caterpillars are often captured by this animal. It would seem that such heavily armored insects as the spiny Vanessa caterpillars would escape the toad, yet in spite of their natural protec- tion they are gathered in without apparent discomfort. The damage caused to the elm, willow, and apple by these insects is a matter of common knowledge. Elsewhere mention has been made of the capture by the toad of the winged brown-tail moths as they fall partially stunned from the street lamps. The lamps have a strong attraction for the moths, and the toad makes sure that few if any escape. This imported European pest has now become well established in several New England States, particularly in residential districts. It is here that the toad is most valuable as a destroyer of the moths. Four toads taken under electric lamps contained 10, 11, 15, and 17 moths, respectively. The cater- pillars of this insect are but little more fortunate than the moths. Six toads taken in infested orchards contained, respectively, 3, 3, 5, 7, 8, and 12 caterpillars. When we consider oes the hair with sect these insect- are clothed produces a most intense irritation whenever it comes in contact with the human flesh, it would seem that the toad is practically immune from injuries of this class, and that few if any caterpillars are well encugh protected to escape its rapacious appetite once they come within its reach. ECONOMIC STATUS OF INSECTS DESTROYED BY THE TOAD. In the following table an attempt is made to strike a balance between the good accomplished by the toad through its ravages on injurious species and the harm it does by destroying beneficial species: Insect food of the toad classijied as regards economic status. Benefi- 1 Injuri- cial. ous. Neutral. Per cent. | Per cent. | Per cent. 28 ATS cits cin pee mctne tee cach eetee abahtate as Soa selene Cents “iii map oe el eee ae 10s oe eee Injurious beetles ..........------ +--+ --2eee eee e eee e cece eee eee ee eee eee ee eee eeeee[en eee een ee 18 Sow bugs, myriapods, snails, Ct.) iigss-anck.ct sais eee eo nas oa -k'e esas lees cee elaeeeeneeee : 13 Ground IDeetleSLE 2.1... 22 Ola 22 tee Gal eboney See ce case oO Pe ae iy tes GrasShOpPern). Claas odidcaaad aeegend << esorGaee sient ~ motes, and seed 200 69 34.5 aly 8.5 57 feeder and saws. collectedand examined. aOf 94 weevils SS and al recovered, 13 (10 dead and 8 alive) were at mote board. = Of ees dead and alive) recovered, 11 were found in seed, 14 in motes, and 61 in trash from cleaner feeder. WHAT THE EXPERIMENTS HAVE DEMONSTRATED. From the above-described experiments and many observations it has been demonstrated that seed cotton carried by the powerful suc- tion of the fan may strike directly against the wire-screen separator and the weevils contained may not be injured in the slightest degree. These same weevils may be again taken with this same seed cotton from the storage house and driven against another distinct wire-screen separator in the pneumatic system. Thence they may pass down through the screens at the rear of the picker roller in the cleaner feeder and may be carried along with other foreign substances sepa- rated from the seed cotton by the screw conveyor connected therewith. In case the insects pass through the screen in the pneumatic elevator chute they pass through the main fan and are killed. In case, how- ever, they are not separated from the cotton by the picker roller in the cleaner feeder they may pass through the saws of the gin with the seed into the seed chute, or drop with the motes from the mote board. PRESENT SYSTEMS OF HANDLING AND GINNING SEED COTTON. In the following pages, practically all of the methods of handling and ginning seed cotton in use in the United States at the present time will be discussed, with a view to pointing out the weaknesses of the 209 15 several systems in regard to destroying or controlling the boll weevils. The matter is a rather complicated one, owing not only to the diversity of the different systems of ginning the staple, but the frequent com- bination in one plant of parts of these different systems. Moreover, there is at present considerable activity in the improvement of ginning machinery, resulting in frequent important changes. This discussion, however, will enable any ginner, no matter what his system, to learn the exact point at which the weevils escape, and will consequently show him in what manner the danger of disseminating the pest may be avoided. Moreover, several new suggestions in regard to special cleaners are made in the following pages, and it is hoped that manu- facturers and ginners will be able to make use of them. HAND SYSTEM AT SEED-COTTON STORAGE HOUSE. This class of storage house is used principally in localities where gin- ning for custom is done exclusively, where farmers desire to bring a portion of a load of cotton at a time, allowing it to accumulate until it amounts to a bale or more, and at large ginneries during the latter part of the season when the gins are not running full time. The seed cotton is placed in bins without any special machinery whatever. At gins where the seed cotton is unloaded by this system it appears that all boll weevils must pass with the seed cotton into the gin house. The ginner must therefore depend upon devices in the gin house proper, to be described later, for separating weevils from the seed cot- ton. It is therefore unnecessary to enter into details of unloading seed cotton by hand. We may take up the more modern systems of unloading by mechanical devices, which keep the boll weevils under more or less control. CARRIER SYSTEM OF UNLOADING SEED COTTON INTO STORAGE HOUSE. This system consists of an endless apron running from the wagon to the bins. It was in use previous to the advent of the more modern method of blowing seed cotton to the storage house or to its various compartments. As far as the control of the boll weevil is concerned it does not differ from the hand system. SUCTION SYSTEM OF CONVEYING SEED COTTON FROM WAGON TO STORAGE HOUSE. This system can be conveniently presented under three heads: (1) With safety fan; (2) with one fan and vacuum box; (3) with two fans and vacuum box. With safety fan.—tIn the safety-fan system the seed cotton is drawn from the wagon by suction, and is separated from the air current by a screen within the fan. The blast from the fan is used to blow the 209 16 seed cotton into any desired portion of the storage house. In this system, a few boll weevils may be killed by striking against the screen. Those that pass through the meshes of the screen are forced through the fan, where they are undoubtedly destroyed. It is safe to say, however, that the majority will pass along with the seed cotton. With one fan and vacuum box.—According to the second plan an ordinary fan is used. The seed cotton is drawn from the wagon by the suction of the fan, and separated from the air inside the vacuum box by means of a wire screen. The balance of the operation is the same as in the preceding case, except that a sand pocket is provided at the rear of the screen, thus allowing a large portion of the débris to fall into this chamber, where it is prevented from passing through the fan. The accumulated débris is usually cleaned out at frequent — intervals and thrown about the gin yard, liberating any weevils that may have passed through the screen, as in the preceding case. Though some weevils may be killed by the action of the fan, the great majority of them pass along with the seed cotton. With two fans and vacuum box.—According to the third plan, the vacuum box provided, as in the preceding case, is connected with two ordinary fans, the first of which is used for suction and the second for blowing the seed cotton into any desired portion of the storage house. From the standpoint of controlling the boll weevil this arrangement has no special advantage over the preceding one. The vacuum box is frequently used as a cotton dropper. In such cases the seed cotton is dropped directly into a feeder standing beneath it. If this feeder were fitted with the cleaning attachments, to be described later, an excellent means would be provided for destroying many of the weevils that would otherwise pass to the cotton-seed storage house. Special droppers.—In addition to the above-described system, some concerns manufacture special droppers which pass the seed cotton over a large screening surface before it becomes dead and falls upon the floor or is blown into compartments. The débris, which may include weevils, extracted during the movement of the seed cotton over the screen, passes through the fan, by the action of which the insects would undoubtedly be destroyed. Such devices are useful in reducing the number of weevils in the seed cotton before it reaches the gin house proper, but none of them can be depended upon to eliminate all of the weevils. Their work would be much more effec- tive if they were provided with beaters, or a series of beaters, to throw the seed cotton against the screen, thus separating every one of the locks. Undoubtedly one of the most important suggestions to be offered is that more extensive use be made of these devices. The more seed cotton can be agitated, the greater the probability that the 209 17 weevils will be removed, and when the débris is passed through the fan, there is no probability that any insects will escape alive. HAND AND BASKET METHOD AT GIN HOUSE. In this system the seed cotton is unloaded directly from the wagons into baskets and placed in the feeder. The feeding is accomplished by the movement of an inclined carrier belt which moves the cotton forward and against the picker roller which separates the locks and drops them directly into the gin breast. A considerable amount of sand, gravel, and in many cases weevils, is separated from the seed cotton and dropped either directly upon the floor or into the trash box at the lower portion of the hopper. As a rule the trash, including weevils, is thrown into the seed conveyors, whence it reaches the seed boxes or cars. It will be readily seen that weevils are practically unrestricted by this system, although the collection and destruction of the trash instead of returning it to the seed would eliminate a large number of them. The hand and basket method of feeding the gins is in use at nearly 9 per cent of the ginneries in Texas and at 444 per cent of those in Louisiana. PNEUMATIC SYSTEM WITH BELT DISTRIBUTORS. In this system the seed cotton, either from the wagon or the stor- age house, is drawn by suction from the fan or driven by a blower against a wire screen. The fan or blower is placed in various posi- tions in the gin house. The wire screen in the separator is the most essential part of the apparatus. Its use is to separate the dirt from the seed cotton and to prevent the seed cotton from passing through the fan and being discharged either into the open air above the build- ing or below into the receptacles for seed. Some manufacturers have provided a box for catching the trash at the rear of the screen or beneath the distributor belt. ‘The seed cotton is dropped upon the distributor belt and deposited in hoppers and open feeders resting horizontally upon the gins. The amount of seed cotton fed upon the belt is to some extent uncontrollable. When all the hoppers are filled a surplus accumulates. This surplus seed cotton drops upon the floor and is from time to time drawn up by suction into the vacuum box or separator, whence it again reaches the distributor belt. In the distributor-belt system the seed cotton is dropped into an open feeder, which is a convenient term for differentiating feeders used with this system from those used with the pneumatic system, in which all seed cotton and mechanical devices for cleaning it are entirely inclosed. There are many different styles of these feeders, but the essential point for the present purpose is that they are all open. The 209 18 bottom of the hopper of these feeders consists of an endless movable apron which carries the seed cotton forward and against the picker roller or spiked drum which separates the loose locks and deposits them in the gin stand. In this class of feeders all of the trash, boll weevils, immature locks of cotton, etc., which does not fall through the picker roller is carried with the seed cotton and falls directly into the gin breast. At the present time it may be safely stated that nearly all the residue which falls between the spikes of the picker roller is swept from the top of the gins and deposited in the seed conveyor, through which it is blown or otherwise conveyed into the seed storage house, cars, or farmers’ seed boxes. The spread of weevils is facili- tated by the use of this class of open feeders with the distributor- belt system, though the apparatus as in use at the present time has considerable advantage over the hand and basket system. The prin- cipal advantage is that the seed cotton is elevated by suction and beaten direct] y against the separator screen, where a certain number of weevils may be killed. That the number thus killed or removed is small has been proven by many observations. An important suggestion in con- nection with these open feeders is that a receptacle should be furnished for catching the débris which falls from the picker roll. This trash could easily be carried to any desired point by a spiral conveyor. The most important weakness in the belt-distributor system is found in the overflow that accumulates on the floor at frequent intervals. Many weevils in the seed cotton thereby have a chance to escape to any part of the ginhouse. This danger is obviated altogether in the system next to be described. It is needless to state that from the ginner’s standpoint, manufac- turers have obtained perfection in this system. The present objection could be obviated, to some extent at least, if the overflow from the dis- tributor belt were fed into a weevil-proof box or bin, whence it might be re-fed directly into the gins or into cleaner feeders connected there- with. There are, no doubt, mechanical difficulties to be overcome in making this change, but at present it appears that they are not insur- mountable. PNEUMATIC SYSTEM WITH CLEANER FEEDERS. This system has the decided advantage over the pneumatic system with distributor belt that there is no overflow, and all weevils that are in the seed cotton must be deposited within the feeders. A great deal of ingenuity has been used in the construction of the feeders considered under this head, but the principles upon which they operate are very similar. In Texas 333 per cent and in Louisiana 194 per cent of the ginneries are provided with these feeders. Use of the cleaner feeder.—In these machines the seed cotton is drawn through tubing to the pneumatic elevator resting directly upon the 209 a che 19 feeder itself, which in turn rests upon the top of the gin stand. The seed cotton is separated from the air current by the screen, where it becomes dead and drops into the closed hopper, the mass passing gradu- ally between fluted rollers, from which it is received by a picker roller making about 170 revolutions per minute. As each lock of cotton reaches the picker roller itis revolved many times, being beaten against a curved screen which has generally a clear opening of one-third of an inch. It is then discharged directly into the breast of the gin stand. The screen and al] other parts mentioned are inclosed in tight casting, so that the weevils that may be contained in the seed cotton must either be removed by the action of the picker roller upon the screen or pass with the seed cotton into the gin breast. As is shown on page 14, about 70 per cent of the weevils are separated by the cleaner feeder and about 30 per cent pass into the gin, from which they are thrown out either with the seed or with the motes. In case they pass through the screen with the general trash, they fall directly upon the spiral conveyor, which is continuous from one end of the battery of gins to the other, and are discharged into a spout leading to a trash receptacle, usually placed below. In plain feeder gins, however, as has been noted, this trash is either deposited at the rear of the gin, or is carried to the seed conveyor through which it is blown or carried with the seed to the cars or seed house as may be desired. To sum- marize, with the pneumatic and cleaner feeder system, there are three avenues for the escape of the boll weevils. (1) Any specimens that may be drawn by the suction of the fan through the screen above the hopper would have to pass through the fan, which ordinarily makes from 1,500 to 2,000 revolutions per minute. Experiments have proven that they are killed under such circumstances. (2) Any weevils that remain in the seed cotton as itis driven by the revolving picker roller against the screen at the rear will pass with the seed cotton directly into the breast of the gin and upon the roll of seed cotton which is rotating at all times during the operation of ginning. After reaching this situation, they may pass along with the seed into the seed conveyor, or be thrown out at the mote board, or pass with the lint to the baling machinery, as has been proven by experiments, the details of which have been given in preceding paragraphs. (3) All weevils separated from the seed cotton by the action of the picker roller in beating against the cleaning screen must be confined to the space below the screen. As there is no other avenue of escape, they must fall upon the spiral conveyor and thus be carried to the outer end of the battery of gins, where, as before stated, with most gins, all the trash is conveyed through a spout leading directly into the seed conveyor. 209 20 On account of the weevil’s habit of becoming quiet when disturbed, it has been found that there is little danger of individuals that have been fed into the spiral conveyor crawling out before the trash is deposited. This slight danger may be partially obviated by simply covering the conveyor box between the gin stands, so that the only openings into it will be within the screening chamber, and the only outlet will be at the spout leading to the trash receptacle. Apron cleaner feeder.—This cleaner feeder is designed for use with the basket system of feeding at small ginneries, and also with the dis- tributor-belt system. All the trash, including the weevils, which falls from the revolving apron drops directly upon a spiral conveyor and becomes mixed with the trash removed by the picker roller, beating the seed cotton against the screen beneath it. Both weevils and trash are carried through a pipe at the end of each gin and discharged into the seed conveyor, or a box placed below or upon the floor. In these cleaners the screw conveyor is the length of one gin stand only, and is not connected through a full battery of gins, as is the case with the ordinary cleaner feeder previously described. In order to make it accomplish the same result as in the upright cleaner feeder, it would be necessary to convey the trash through spouts from each separate gin, leading, at the rear of the battery of gins, into a spiral screw con- veyor, which would carry the trash to any point desired. This spiral conveyor should discharge between compression rollers, or other devices which could be easily provided, whereby all insects reaching them would be destroyed. This method of destruction will be detailed more fully in the recommendations. Special cleaner feeders.—In addition to the ordinary and apron cleaner feeders, which have been described, special forms are now manufac- tured by some companies, and there seems to be considerable activity in improvements in this line of ginning machinery. In some cases _ these devices combine elevating, cleaning, distributing, hulling, and feeding operations. In the ordinary cleaner feeders the seed cotton is drawn by the suction of the fan and separated from the current of air by a screen. The cotton usually strikes the screen in a more or less compact body, so that comparatively few weevils are driven through this screen. In the improved systems, however, the seed cotton falls directly upon a revolving beater, which drives it against the screen and separates the locks thoroughly. In some cases the cotton is then passed on to another beater, revolving against a similar screen, thus giving it two thorough workings. As the full force of the air passes through these screens, all boll weevils and trash, sepa- rated by the combined beating and screening operations, are passed through the fan and thereby destroyed. In one form of feeder, in addition to the two beaters, a picker roller is used, and below that a 209 2] huller feeder leading to the gin itself. In connection with the picker roller is a trash flue, and in connection with the huller there is a spiral conveyor for such trash as may have escaped the preceding operations. There can be no doubt that this system is very effective in extracting the weevils from the seed cotton and destroying them. From the present standpoint, however, these machines have the weakness of requiring a belt distributor, because of the fact that the air passes through the screens before the cotton reaches the lower portion of the device. As has been pointed out previously, there is great danger of the weevils escaping and spreading from the surplus which the belt distributor deposits upon the floor of the gin. However, in this case, the very thorough beating and screening’ through which the cotton has passed undoubtedly largely removes this objection. Although no actual experiments have been performed, it seems certain that prac- tically all of the weevils will be extracted from the seed cotton before it reaches the belt distributor. This system undoubtedly constitutes one of the most thorough cleaning devices for cotton now known. SEPARATE CLEANERS. Considerable ingenuity has been exercised in perfecting another class of cleaners, which are separate machines and movable from one point in a ginnery or seed-cotton storage house to another. They are used either in connection with the distributor-belt system at the gin or in the seed-cotton storage house for simply dropping the cotton, or blowing it into stalls or compartments. These machines consist of a picker roller or drum, revolving rapidly against a screen. The débris passing through the screen, which would include many weevils, is drawn through a fan and discharged at various places. These machines have superior merit for cleaning the seed cotton, as they have a very large arc of contact on the screening surface. The speed at which the picker roller is revolved, greatly exceeding that attained in the case of the ordinary feeders, is another decided advantage. The weevils forced through the meshes of this screen are carried through the fan, where experiments have shown that they will be destroyed. It is consequently immaterial whether the trash is blown about the gin yard or into the seed conveyor, as is sometimes done. Unfortunately these excellent machines are not likely to come into general use at the large ginneries for the reason that the seed cotton in passing from the wagon to the bale would have to be rehandled and refed through another suc- tion pipe leading to the gins. The modern cleaner feeders seem to be taking the place of nearly all separate and distinct cleaning devices at the gins. Nevertheless, where seed cotton is taken from the wagons in baskets and fed into the gin stands these machines would be of very decided advantage in eliminating the weevils. 209 22 In addition to the various cleaners already described, an entirely distinct machine is now made to be interposed hetween the cotton sup- ply and the type of pneumatic elevator, the apparatus forming a section in the supply pipe. This machine is, however, also used as a separate and independent cleaner, which may be moved to any place in the ginnery. In either case the seed cotton is beaten against a cylindrical screen, being manipulated in such a way as to become practically dead when it falls upon the beaters. The action of the arms of the beaters carries it through the apparatus, giving it constant agitation against. the screening surface, which in this cleaner is far greater than that used in any other type. The weevils and other débris escaping through the meshes of the screen fall onto a spiral conveyor below, which car- ries them to any point desired. By passing the discharge through a pair of compressed rollers all weevils would be destroyed, and it would then be immaterial whether the trash were returned to the seed or deposited elsewhere. There seems no doubt that this system would be exceedingly effective in removing and destroying the weevils. GINS. There are two principal classes of gins in operation in the United States, known, respectively, as plain and huller gins. In addition to these the roller gin is used principally in sections where Sea Island cotton is produced, and a modification of the saw gin, known as the needle gin, may eventually come into quite extensive use. Theavenues of escape of boll weevils from the ordinary saw gins have been described in the preceding pages. In Texas 93 per cent and in Louisiana nearly 42 per cent of all the gins are of this type. The huller gin—The huller gin is used particularly in sections where, owing to labor conditions or other causes, the usual care can not be observed in picking, and consequently more or less of the bolls, boll hulls, and other trash are gathered with the cotton. This gin is supposed to yield a better sample from trashy cotton than can be obtained from the plain gin, and seems to be growing in popularity. With the huller gin the seed cotton is fed into the outer breast, where it drops upon a rapidly revolving huller roller which carries it to the saws. The hulls, bolls, etc., are stopped by the projection of the ribs, | while the seed cotton is carried by them into the inner breast, where it is ginned. With the case of the huller gin, it seems likely that more weevils will be deposited in the seed than is the case with the plain gin, on account of the fact that they are allowed to drop with the trash into the seed without going through the saws, as is the case in the plain gin. It seems certain, therefore, that the spread of the weevil must be greater with the open feeder and the huller gins than with the open feeder and the plain gins. Nevertheless, there would be no 209 23 difficulty in passing the seed cotton through any of the numerous forms of cleaner feeders before it reaches the outer breast of the huller gin, and this would obviate entirely the objection that has just been men- tioned. In Texas nearly 7 per cent of the gins are hullers; in Louis- jana, 58 per cent. : The roller gin.—In roller gins the seed cotton is thrown into a hop- per, whence it is drawn by friction between a grooved or corrugated roller, made of rubber, walrus hide, or some other substance, which presses against a knife. Various methods are used for removing the lint from the roller, as well as for striking the seed from the lint as it is drawn against the knife by the action of the revolving cylinder. It seems likely that in this system some of the weevils would be killed by the doctor knife or by the beater knife used to remove the seed. Nevertheless, a large percentage of them would necessarily pass along with the seed and be conveyed to the seed house. There would be no difficulty in using cleaner feeders to deposit the cotton in a hopper, although special contrivances would be necessary on account of the slow rate at which the cotton is usually ginned by this process. A large portion of the effectiveness of the cleaner feeders is due to the rapidity at which the spiked roller revolves. This would probably result in feeding a heavy surplus into the hopper. It would be an easy matter, however, to arrange astorage for the surplus. The cleaner feeder might be stopped while the surplus is being ginned. The needle gin.—The needle gin is simply a huller gin with a system of needles set upon a cylinder instead of saws. For the present pur- poses it is not essentially different from the ordinary huller gin. HANDLING COTTON AFTER GINNING. Between the gin and the baling apparatus the lint is handled by two separate systems, the open-condenser system and the lint-flue system. Open-condenser system.—In the open-condenser system all of the lint from-each gin drops directly upon the floor. -When a sufficient quan- tity has accumulated to make a charge it is drawn along on the floor by hand or forks and deposited in the press. During this treatment weevils in the lint, of course, have abundant opportunities for escape. The condenser itself consists of a circular wire or perforated screen drum inclosed in a framework of iron, wood, canvas, or other material, leaving sufficient space to allow the escape of air, dust, etc., from the gin stands. In some cases there is an opening through the floor through which the air escapes, while in a battery of two or more gins the air discharges through double dust and air flues through the roof | of the building. The air-tight lint flue—In modern ginneries, however, the open- condenser system is being done away with, and the air-tight lint flue 209 24 is used in connection with the battery of gins having one large con- denser. In this system the weevils have no opportunity to escape from the lint between the gin’ and the baling apparatus. There fol- lows naturally the suggestion that wherever possible the inclosed lint flues should be used, thus allowing no avenue of escape for the weevils, which must pass through the large condenser and there drop directly into the press. SUGGESTED IMPROVEMENTS IN DEVICES FOR HANDLING AND GINNING COTTON. From the preceding accounts it will be seen that many of the devices that have been perfected for cleaning cotton, and thereby improving the sample, are incidentally of great value in eliminating the boll weevil, although none of those tested have been found to be perfect. The following recommendations look toward the modification of these devices in such a way as to increase their efficiency. As the general trend in cotton ginning is toward improving the sample, and as these suggested modifications also accomplish that result, they should be considered carefully by all ginners. IN THE SEED-COTTON STORAGE HOUSE. At many of the smaller gins throughout the country the ginhouse and seed-cotton storage houses are combined under one roof. This is the case at 54 per cent of the ginneries in Texas and at 11} per cent of those in Louisiana. Many of these buildings have no partitions, the seed only being kept as far from the seed cotton as possible. Although it is understood that in many cases it would not be possible for small ginners to provide separate houses for storing the seed cotton and the cotton seed, nevertheless in some cases it could be done without spe- cial inconvenience. It is very evident that where weevils are present the combination of the three houses under one roof is not advisable. Where the seed cotton is unloaded by hand directly from the wagons into the storage house nothing can be done to destroy the weevils that are brought in with the seed cotton except by the installation of one of the various forms of separate cleaners or droppers. During the latter part of the ginning season a great deal of seed cotton is handled by hand, even at large ginneries, and does not pass through any machinery in the seed-cotton storage house. In such cases it will be necessary to pay particular attention to methods of eliminating the weevil in the ginhouse proper by means of cleaner feeders, cotton cleaners, separators, etc. In all seed-cotton warehouses where elevat- ing pipes are used for receiving the cotton from the wagon and dis- charging it directly into the room below, or for blowing the seed cotton to different compartments, the most important feature is the 209 25 _ separator itself. This is a perforated wire screen which prevents the seed cotton from passing through the fan. At this separator an effective apparatus for cleaning the seed cotton should be introduced in order to force the weevils that may be removed through a fan. This end might be attained by providing beaters or spiked picker rollers, revolving as closely as possible to the wire separating screen, having the meshes opening one-third of an inch in the clear. The screening surface should be as large as possible. The picker rollers ~ or beaters should run at a high rate of speed. Under these circum- stances the suction of the fan would draw out the great majority of the trash which would pass through the fan, thus causing the destruc- tion of the weevils. There is no doubt that the number of weevils could be very materially reduced by such contrivances, which are now manufactured, although it is not possible that all weevils could be eliminated in this way. Some additional horsepower would be necessary, by reason of the rapid running and extra machinery here recommended. However, it is probable that not more than one additional horsepower would be required. The great majority of the gins undoubtedly have one or more horsepower to spare; still in some cases the lack of a surplus would interfere with the adoption of this recommendation. IN THE GINHOUSE PROPER. From the foregoing pages it will be evident that wnile some of the systems of handling the cotton in the ginhouse proper are more or less effective in eliminating the boll weevil, none of them are abso- lutely so. The most defective of the mechanical devices are found with the plain feeders, front plain feeders, and huller gins, in connec- tion with the handling of the seed cotton by hand or by distributor belts. In such systems all trash, sand, boll weevils, etc., fall directly to the top of the gin stands or to the floor, or directly into the seed conveyor, whence the weevils may easily reach the seed house. On the other hand, many of the modern cleaning feeders and cotton cleaners have valuable features as far as the control of the boll weevil isconcerned. They confine all of the trash removed in spiral conveyors, where it is under perfect control. The trash from the battery of gins should be carried through a single spiral conveyor, which should be closed between the gins. At the present time the usual method is to scatter this trash broadcast about the gin yard or to pass it into the seed conveyor and thence to the seed house. From this place the weevils that may be contained are frequently transported long distances in seed for planting purposes. It would be a very simple matter to pass all this trash from the battery of gins between two compression rollers made of either wood, iron, or other hard substance, having sufticient 209 26 strength to crush all of the weevils that might be contained. After that has been done it would be immaterial whether the débris was scattered about the gin yard or sent with the seed to the seed-storage house. | The installation of the compression rollers would, therefore, not inter- fere with the trash taking exactly the same course as it does at the present time. It should be noticed in this connection that the very important point is in having the spiral conveyor continuous with the whole battery of gins and having only one outlet. With some of the cleaner feeders there are separate screw trash conveyors for each stand, situated under the front of the feeder. In such cases it would be necessary to carry the trash from the pipes that are generally pro- vided into one continuous conveyor discharging at one end, where compression rollers could be applied in the manner that has been mentioned. With the belt-distributor system, it will be necessary to provide a box for the overflow of seed cotton. If the seed cotton is scattered over the floor, the weevils can escape more freely than if dropped into this box. A better method, however, would be to provide, in connec- tion with the separator and vacuum box, a complete cotton cleaner and separator combined. Thus the seed cotton would be practically freed from weevils before it is dropped upon the distributor belt. With the present huller gins and plain feeders, the boll weevil is kept under less control than with plain gins. All live boll weevils which become loosened from the seed cotton while on the feeder roller neces- sarily fall down into the seed conveyor and pass out with the seed; with the plain gin, on the other hand, the seed cotton is fed directly into the breast or roller box of the gin, thus coming in contact with the saws immediately. However, this apparent objection to the huller gin could be entirely obviated by the placing of a cleaner feeder above the stand. With the plain feeders now used the boll weevils are kept much less under control than with the modern cleaning feeders. The seed cotton is dropped upon an endless apron and conveyed against the picker roller, which separates the locks, elevates them, and deposits them directly in the gin breast. Hence all weevils not carried up and deposited directly in the gin breast, or with the huller gins in the outer breast, drop through the full width of this endless apron feeder upon the top of the gin stands and are there scattered in all directions. A practical suggestion concerning the elimination of this difficulty is in the attachment of a movable bottom sheet beneath the apron wherever this would not interfere with the operation of the gin. In some cases there might be difficulty on account of the small space between the revolving apron and the top of the stand. However, wherever a false bottom could be used, all of the trash, including the 209 . 27 weevils, could be made to slide directly into a continuous spiral screw conveyor at the rear of the gin stands. The screw conveyors for the separate gins could easily be made continuous, and the discharge from the full battery of gins could be passed through compression rollers at the end. ; From the preceding paragraphs it will be seen that by the installa- tion of cleaning droppers in the seed-cotton storage house and of special cleaners in the ginhouse proper, a great majority of the weevils could be brought under control. Nevertheless, with any of the devices that have been studied, it is apparent that a number of weevils reach the gin itself, and that a considerable percentage of these escape alive, either in the seed or at the mote board. These two avenues of escape illustrate the greatest weakness, as far as the boll weevil is concerned, of the various cleaners which are perfectly constructed for the objects the inventors have had in mind—i. e., simply removing the trash from the cotton. Further inventions may possibly bring about still further perfection in this system of cleaning cotton, but at present manufac- turers should devote some attention to the construction of contrivances which will eliminate the weevils from the seed and motes. There would apparently be no insurmountable mechanical difficulties in caus- ing the motes to run to the seed as it falls from the gin. If this could be done and the combined seed and motes could be cleaned by passing along screens in connection with some agitating device, like a picker roller, or over an oscillating perforated bottom, the weevils would be shaken below and there collected by a spiral conveyor and destroyed by means of a pair of compression rollers. It is believed that practi- cally all of the boll weevils in the seed could be destroyed by these means. In case of the use of a screen and picker roller, at least where two fans are used in the elevating system, it would be an easy matter to obtain the desired suction, without involving any additional horse-— power whatever. In case of the use of the oscillating bottom, the only additional horsepower necessary would be the very small amount required for causing the agitation and for running the compression rollers. Either device might easily be introduced between the seed chute at the gin and the blower, and would thus not interfere materially with the present course of the seed. It will be seen that the advantage in conveying the motes to the seed, as suggested in this plan, is that the weevils from both may be extracted at one operation. However, it would be perfectly feasible to collect the motes independently by means of a spiral conveyor and to destroy the weevils contained therein by means of a pair of rollers. It seems to the writer possible that suction alone might be utilized to separate the weevils from the seed as they are dropped from the saws to the seed chute. At this stage the seeds are thoroughly sepa- 209 28 rated, much more so than at any other stage of handling. An aver- age cotton seed weighs about 2 grains, while an average boll weevil weighs only about one-eighth as much, or one-fourth of a grain. Between such extremes it seems feasible to adjust a suction pipe in such a manner as to remove the weevils. Possibly an air blast instead of suction might be used in forcing the weevils toward the motes, with which they might be collected and destroyed. The suction sys- tem, however, would have the advantage of furnishing its own device for destroying the weevils, namely, the fan itself, though in that case there would still be the necessity for a separate device for the proper manipulation of the motes. It is believed that the suction or blast could be obtained at the ordinary gin without an independent fan. There will, of course, be difficulties to overcome in constructing a device along the lines suggested, among them that of obtaining an even degree of suction or blast the full width of the seed chute, or for a possibly lessened width, into which the seeds might be brought. Nevertheless, the matter is undoubtedly well worthy of experimental trial. The same results as those aimed at by the above-described system might be obtained by the use of sand reels, such as are used in oil mills, in connection with the separate gins, or one large reel for the reception of the combined discharge from the battery. Sand reels, however, are rather expensive machines, and require some additional horsepower. Their installation at gins is, therefore, considered much less practicable than the installation of some such device as has been suggested. CONTROLLING THE BOLL WEEVIL AT OIL MILLS. Under the present arrangements large numbers of weevils concen- trated at the gins in the seed cotton reach the seed house, whence they are conveyed in cars or wagons to the oil mills. There are several avenues of escape at these mills. It has been demonstrated that cot- ton fields in the vicinity of oil mills which have received seed from infested territories become infested by the weevil sooner than others. The weevils liberated from the seed at the mills frequently get into by-products, particularly hulls, and have been known to be trans- ported to barns when the hulls were carried from the mills for feed- ing purposes. With the present generally rather ineffective methods for controlling the weevils before the seed reaches the oil mill, control at the mill is scarcely less important than at the gin itself. When the seed arrives at the mill, it is generally unloaded from the farmers’ or ginners’ wagons or cars directly into the storage house by hand, although in some cases screw conveyors are used for this pur- pose. However, after the seed reaches the storage house the methods 209 29 of handling it are identical. It is shoveled into large spiral screw conveyors, which in some cases have solid and in other cases perfo- rated-screen bottoms. These conveyors discharge directly into the elevator cups, which in turn deposit the seed in another spiral screw conveyor. This brings the seed to the cleaning apparatus, known as a *‘boll reel.” This is a perforated cylinder, revolving within a closed box. The perforations of the cylinder are larger than the seeds, allowing them to fall through into the closed box below, while retain- ing larger substances, consisting of bolls, carpels, pieces of cotton stalks, and sweepings, and the general trash from the ginneries. This trash is usually picked over by hand and such portion as may be of value is placed with the seed to pass through the linters. The balance of the trash is deposited in various ways about the building or outside. From the boll reel the seed is conveyed to a sand reel, which consists of a revolving steel cylinder, having perforations smaller than the cotton seed. Up to this point in the handling of seed at the mills, except in those cases where the conveyor has a perforated lining and supplementary screw conveyor for the trash, there are no devices that would have a tendency to eliminate the weevils. However, the sand reel permits boll weevils and other trash—in fact, everything smaller than the seeds—to pass to the chamber below, from which it is usually removed by hand and scattered outside of the buildings. It is very evi- dent, therefore, that this is one point where the weevils are given an opportunity to spread from the oil mills. Nevertheless, excellent oppor- tunity for the destruction of the weevils that have come from the gins is given at this point. This could be accomplished easily by collecting the refuse from the sand reel by means of a spiral conveyer, and pass- ing it between such compression rollers as have been described previ- ously. It is evident that all boll weevils remaining in the seed after — it has passed through the sand reel must be carried with the clean seed through air-tight pipes into the seed hopper, which drops them upon the saws of the linter. Should any of the weevils escape the action of the sand reel they would cena be killed by the close action of the saws of the linter. Another very important point to be inetionsas is in connection with the carriage of the seed to the oil mill proper. As has been stated, the conveyor runs the full length of the storage house on the outside of the building. In cases where a perforated bottom is provided, the refuse smaller than cotton seed passing through the bottom, which may include many weevils, is simply allowed to fall upon the ground. In other cases, however, this residue is collected by a spiral screw conveyor, to which compression rollers for the destruction of the weevil could be easily attached. If the screw conveyor were provided with an unperforated lining at the bottom, it would carry all weevils 209 30 which might not crawl out in transit to the elevator cups and thence to the sand boll reels. Most of the machinery used in the movement of the seed runs at a slow speed, and therefore a considerable percentage of the weevils may escape to the open air. From the foregoing paragraphs it will be seen that to control the boll weevil at the oil mills would be a very difficult matter. The escape of the pest to the open air and to the hulls is allowed by the present necessary system of hand manipulation and the open con- veyors with slowly revolving screws. The only recommendation to be made is that all conveyors should be provided with perforated bot- toms, and that the trash passing through should be collected by means of a small spiral conveyor and passed between rollers. It is never- theless true that this process would destroy only a small percentage of the weevils at the mills. The impossibility of applying any very effective method at the mills emphasizes strongly the necessity of vigorous attempts at the gins. SUMMARY OF RECOMMENDATIONS. It should be understood that complete success in keeping the boll weevil out of cotton seed depends upon a combination of the following recommendations for the seed-cotton storage house, in addition toa combination of the recommendations for the ginhouse proper. No one alone could be depended upon. On account of the great serious- ness of the boll-weevil problem, the importance of these recommenda- tions deserves the careful attention of every ginner, and farmers should realize that it is decidedly to their advantage to have their cotton ginned where the greatest care is taken with the seed. I. Where possible, a separate seed-cotton storage house should be provided. In any case, the seed should be stored in a building distinct from the seed-cotton storage house. II. In the seed-cotton storage house should be installed special cleaners or droppers, which, in addition to removing many weevils, would facilitate ginning and improve the sample. III. In the ginhouse proper the principal recommendations are that cleaner feeders and cotton cleaners be used more extensively, that the trash therefrom be treated in such a way as to cause the destruction of the weevils, and that a device be perfected for removing and destroy- ing the weevils in the seed and motes. IV. Wherever the system of handling and ginning cotton is not found to be effective in removing the weevils, and this is the case in practically all the smaller and many of the larger ginneries in Texas and Louisiana, the seed, at least for planting purposes, should always be sacked and fumigated by the ginner in the manner described on 209 { : | a 31 page 9. In regions where the cotton fields are isolated by this means the introduction of the weevils could be delayed considerably. V. In addition to the care necessary with the seed for planting pur- poses, the farmer should also take great pains to prevent the introduc- tion of the weevil in seed or hulls for feeding purposes, as well as in refuse from the ginneries, which is sometimes used as a fertilizer. There is no appreciable danger in cake or meal. VI. At present it does not seem possible to control the boll weevil effectively at the oil mills. The importance the mills at present have in disseminating the weevil, however, could be very materially reduced by the proper care at gins. [A list giving the titles of all Farmers’ Bulletins available for distribution will be sent free upon application to a Member of Congress or the Secretary of Agriculture. ] 209 O apn ber i Bet ie LP . eat Tena tty 7 8B ane iates a ste aa ity io Bf sceogniaabant FWA baos a: as Cake i osu gumbaniom ai, oys Lb Sea Fg SS oui BR cnc. St if lixaaty, » find elk lodges. of, aidieuce, i rm » Orta Aeeoney, 44 ellien odd, POT Leng EEE ; an Sieber, arian THO, hie femal Daas nyse oe mer ren ee seo ON ee ye rt eh 1s ahaa yi, So fAieid scl aldalleva kallolntt Ea {is to. aateet Ree it A Io visbrine? stir 10 mermite) 3a todionlé & ot Go: Lollyqe sOggreaa. : ee ke ae % Seyi eB heath esa) ie Dent 6 > 7] risa bea TER ome me | p eo G ertolA bean nian ae Steer ret hs; ieee SWE ke 2 “20 mM ITE, “Oe aa tt #45 _., ee ME Crete Spee Ria are le ieee aaa } , + i gael aes “erg } rey a4 io pai ae 2 Rit gshrkey Set * es ae Us: DEPARTMENT OF AGRICULTURE. FARMERS’ BULLETIN No. 211. THE USE OF PARIS GREEN IN CONTROLLING THE COTTON BOLL WEEVIL. BY Wi AD. BUNEER, Special Agent in Charge of Cotton Boll Weevil Investigations, Bureau of Entomology. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1904. LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Bureau or Entromowoey, Washington, D. C., December 5, 1904. Str: I herewith transmit & manuscript entitled ‘‘The Use of Paris Green in Controlling the Cotton Boll Weevil,” prepared by Mr. W. D. Hunter, special agent of this Bureau in charge of the experimental work with the Mexican cotton boll weevil in Texas. On account of a widespread misunderstanding regarding the value of Paris green as a boll weevil remedy, it seems important that this manuscript should be published speedily and in a large edition. I therefore recommend that it be issued as a Farmers’ Bulletin. In the work leading to this bulletin, as well as in the preparation of the manuscript, the author has been materially aided by Dr. W. E. Hinds, principal assistant, as well as by Mr. J. C. Crawford, jr., who has been engaged upon the subject dealt with herein throughout the greater part of the season. Respectfully, L. O. Howarp, Chief of Bureau. Hon. James WILson, Secretary of Agriculture. py 8 (ATS AG BH Dee Te ae jen a te a, shan Wh yr y q be ect i ; ; ‘ ae | ene ; i 7” f , ; the i ah}! ete) SUPA eee ‘3 ae OM AN ns te ns SN tA , es A mL Wives nee f te pe in : “es ‘ 7 a - ional Se oth.’ Tp Shee hi an subeanne, a ieee viene re pon a re cu bras mys} 4 ee vow dt (los hy ee we a eet nails 3 Minn reciting ord by bind anf ohio arihd fa) rereK, tucpatpet ee Leiwinoae wO) waxni'l wl [Pisow ok nook fk ek as ‘ee i by ae mrt ein 7 ou ar ae qmkis hog ie paidngehinybqsindin: by iy Ei Maida: ki rranssigag: st$, tay -teedne giant datas dikes hagas Phi cc < Pe Pecerrbarr: aateeieds: b dacthths: anata Rae cof ianeip. Sil ag By probes Bes ee Nee tie beeen ah Baek i ie ae a re taping o i et Hs re ey BH eta ahi. "ah id ni! away hax ay F . Bee. WEE tel Gadete Rket reiheie! trad al Wahbagae wcl Jere ine ts og Hare a A edie Sey ee ert ae thee: - patie espionage ci Aer F Aifomuy cath i aiviee. ca See bopeiubinies ently eee rates iia" Roy | jose Beant ie 5 ; a ieee , SateP A OED CRT ao i ie ee MPM heyy Tie.) < a - 24, hilag oh le ERA yee ee. Sse oa oe PoE eS eran cu eeee baee dance coe Tee Experiments conducted by the U. 8. Department of Agriculture -.........-- Treatment of small areas, with careful examinations ...............----- Conditions covered and methods employed ..........-.--------.---- Eee ei oe re ae cat ae ed Na ee Powon blown by 9. powder fun. ces. c5c- oe noeean Oe sania ee ee HORSONT HELEU PPG MN ANEACK Foot on oe eae as Bee aoe. cee ee eee S(DUDOUO CEN / od A oR ia ER eS 8s RE a ek me Treatment of large areas during season of 1904.........--...-----.------ Preld experiments at, Sam, AMtOMIO. 2 bo: anne woe ete: the ae sineemt Sete Piet CC POUma OTIS Ain WCBS oo 5 oo wc in ae ob aS on elaine « hecin seo ae Reig expenimenie a0 CaIVeENl oo20.5.0 2 Soins aan a enema a saan Experiments conducted by various planters ....-..-....--------------------- Martens Houston}, Hloreswillevet yt. 9432.8 ee ee a eee ee Biaely. \Wihers; GLeckhart..5-..f 22s 82s teva tad Yous pede ete: Miro aren. Leclhight. 2b 2032) os Shes ie ee eRe saan sea eos S Vian barbes licks: CCQ se peo ase eer eee Sp Ree Ao ee ee Mirae ING VSer Wan IRs wa sceme emcee tase demos so ae Bees Shien Reve oie emrcelle lockbanue 222 4052-580 ms se a ie oe care ree te wee damier spat Gaitn Orn, Seen ets TOUR ee ee. Cee Re ae sees ee Some reasons for apparent effectiveness of Paris green..-...---.--...-------- (Tie LV SHS Ee RE ee ea TO es a SEE a rene Ee Syne ey Summary 211 . . . é . os ot ee eee ee oe - oy + Pag 5 Oey Oa Ti Pte A ed Sy tet ‘hake peut thease cae me eat pain | Minti: +e she ii Mitore {laste La Peet recy anit pr tthe Bree poe ~ ive She attach. tia }) hed bis taps ropa nay r ~ i * i = ns . as > . wae « “sy ‘ . fs Moc tise ia i ; Bs : mi “Bei ae eae e haute each a Oe auntie yi “5 . 54 Ss ane ¢ Sty rUbcedgt Sm a Wak md i v4 6 : : we THE USE OF PARIS GREEN IN CONTROLLING THE COTTON BOLL WEEVIL. INTRODUCTION. During the past season there has been a very extensive use of Paris green in an attempt to control the boll weevil in Texas. This has been due to several mistaken conceptions about the habits of the pest, as well as many misconstructions of the results of applications made | in the field by various parties. It has been known for many years that it is possible to destroy a certain number of boll weevils by the use of Paris green, provided applications are made early in the season before any squares are set upon the plants. At this time the weevil feeds on the opening leaflets, and heavy applications of poison destroy a number of them. Many persons have thus killed a certain number of weevils and have concluded that the number found feeding upon the young plants having no squares represents the total number of weevils in the field. Asa matter of fact, however, abundant observa- tions have proven that a very great majority of weevils do not come from hibernating quarters until after the plants have begun to put on squares. This is shown in Table VI on a following page. After squares are formed upon the plants the weevils no longer feed upon the leaves, but puncture the squares, and are then beyond the reach of poison. It will be seen from the foregoing statements that early in the season a few weevils may be killed by the use of Paris green, and it is from this fact that the idea has taken hold of many farmers in Texas that in this poison they have a specific against the pest. On account of the very great attention which has been called to the proposed method of controlling the boll weevil by means of Paris green the Department of Agriculture has devoted special attention to the matter. Experiments have been performed at different points in Texas upon the experimental farms of the Bureau of Entomology, in which care was taken to eliminate all disturbing factors and to obtain accurate information regarding the possibility of poisoning the weevil. In addition to this work, agents connected with this Bureau have visited practically all of the fields at which, at one time or another during the season, the owners have supposed that satisfactory results have been procured. The Bureau of Entomology has from time to time during the season warned the planters through the press against 211 7 8 placing too much dependence upon poison, but despite these warnings it is estimated conservatively that at least 25 carloads of Paris green have been used in Texas. The rather complete results of the work that has been conducted by the Bureau of Entomology are presented in the following pages. Asa result of all that has been done by the Department, as well as the conclusion from careful examinations of many cotton fields in Texas, the Bureau of Entomology does not recommend the use of Paris green in an attempt to control the boll weevil. The fact that applications of Paris green will kill a certain per cent of weevils upon treated plants has been known to the agents of the Bureau of Entomology for ten years. Its use through the medium of a spray was suggested as early as 1895 (Circular No. 6, new series) and repeated in 1897 (Circular No. 18, new series; Farmers’ Bulletin No. 47) and in 1898 (Circular No. 33, new series). It was, however, recommended then only as a means of killing off some of the hiber- nated weevils before squares appeared on the cotton. Through the repeated experiences of several seasons it had been found that spraying cotton with a solution of Paris green had no pos- itive value in controlling the boll weevil throughout the season, and this conclusion has been generally accepted as well established. Therefore the work of the agents of the Bureau of Entomology with Paris green during the season of 1904 has been confined mainly to the application of the poison asa dry powder. Many claims have been made for the superiority of this method of using the poison and for its efficacy, when so used, as a remedy for the Mexican cotton boll weevil. Early in the spring of 1904 a comprehensive series of tests was begun upon areas sufliciently small to allow every plant to be thoroughly prepared, treated, and examined, so that as far as is pos- sible in the field every weevil might be accounted for and the exact effect of the poison determined under the varying conditions of the test made. Upon more extended areas the Bureau of Entomology has this year conducted field tests extending through the season. Checks were kept in these field tests and the results of the poisoning must be judged by a comparison of the crop records of poisoned and check areas, which in all other respects were intended to be under similar condi- tions and to receive identical treatment. In addition to the field results, determined by agents of this Bureau, the experience of a number of representative, practical planters has been drawn upon. Whatever results might have been obtained upon small areas, it is evident that only results of actual field practice in various localities and by a number of men could ever demonstrate the advisability of adopting or rejecting the use of dry Paris green in the fight against the weevil. 211 9 EXPERIMENTS CONDUCTED BY THE U.S. DEPARTMENT OF AGRICULTURE. TREATMENT OF SMALL AREAS, WITH CAREFUL EXAMINATIONS. Conditions covered and methods employed.—In the following series of tests, in order that the number of weevils killed by the poison might be accurately determined, the plants to be treated were carefully examined to find the number of weevils. present, disturbing them as little as possible. A tag bearing all necessary information regarding the conditions of the test and of the weevils was placed with each plant. Papers were then spread under the plants, extending con- siderably beyond the spread of the branches to catch the dead weevils. In spite of this precaution it was soon found that a large proportion of the weevils were missing when later examinations were made. As soon as this fact was observed weevils, so marked with colored pencils as to be positively identifiable, were used, the weevils so marked con- stituting over 76 per cent of the total number treated. The tests were conducted from April 19 to May 19, giving a range of weather condi- tions. These were varied by making applications on calm and on windy days, some early in the morning while the plants were wet with dew, others during the middle of the day when the plants were dry, some in the middle of the day but spraying the plants to give dew conditions. Plants with and without squares were treated, and in three of the tests plants used in the test immediately preceding were re-treated, together with the weevils surviving the previous test, thus making conditions as severe as was possible. In part of the tests the poison was applied with a powder gun, and in the remainder was used the method employed for many years in using Paris green against the cotton-leaf worm—of shaking the poison from a sack. An exceed- ingly heavy rate was used, since the object of the tests was to kill the weevil if it were possible to do so with Paris green. Spraying.—On April 27 a test was made with a spray consisting of 1 pound of Paris green in 30 gallons of water, 49 plants with 94 wee- vils on them being thoroughly sprayed. At the last examination, made 72 hours after the application, 78 weevils were found alive, 5 dead, 11 missing; 82.97 per cent surviving. Since this test was not as successful as the tests with dry Paris green nothing further was done with the spray. On this point Prof. E. D. Sanderson (Farm and Ranch, October 8, 1904, p. 16) says: The dry dust also seems to kill the weevils somewhat more quickly, though in the liquid form the poisons are just as fatal. Poison blown by a powder gun.—-The plants were dry when treated in three of these tests, and the powder was blown in from all direc- tions. Four tests (Table I, Nos. 1, 2, 3, 5) were conducted on seppa 211 10 plants without squares. - The application of poison, though not meas- ured, was heavy in comparison with those tests in which the poison was sifted from a sack, so that it must have been much heavier than at the rate of 20 pounds per acre (as conservatively stated in Table I). The total number of weevils used was 173. The average time elapsing between the application and the last examination was 48 hours. The number of weevils found alive in the four experiments was 37.49 per cent, dead 39.94 per cent, and missing 22.62 per cent of the total number treated. Taste I.—Results of treatment of cotton plants with dry Paris green. - n Done | % ft lno.s | 1 oe | cee : Tee is Fie ‘ é/ 3 = 253 }> | 2 (see | oo | 8d | S. |-se | So | Ss. Zi s So tee eae Oa es vy see Bo | Bn BS | Bos ~ 0g ny eee pelted lia prtssie | S | Pr) Et el wee oe el vie aks Nae le =< MR a= i eS 38 Bc. | og | 8a 53 og Sq | OF at habe Foal ao) od ted Ce | | aon H) Se [52 l¢.Sasige| se p88e) 58 | g8 | se | BB | 2 | Be 5 Ce a ee a ng = a =P af 2 GA jekesal es" | 9" |gSu8) ga A» as 7” Bs ae | Os s jaehaals | 8 |soS8) 52 | Ba | BF | ge | ge | BF a a) Z| pet te eee Ase ee ae | we | a 1..| Apr. 19] 23 20 | 26 1 28 | 6} 10 10 | 23.07 | 38.46 38.47 2..| Apr. 25| 25 20 38 3 Bol ally 14 7| 44.73| 36.84} 18.63 3..| Apr. 26| 45 20 7 2/44 |0 6 27 34 9| 3857) 48.57| 12.86 5. Apr: 28-31. | i eS ee ee 14 8 | 43.59} 35.89| 20.52 ee } ——— = 6..|May 13| 25 | Dl Gite th ve: 28 31 | 7 22} 51.66] 11.66 | 36.68 7..| May 14| 25 20 | 56 1}: 444 8 11 37 | 14.28} 19:62! 66.10 8..| May 16| 41 rt a ee eed 13 62 | 14.77| 14.77 | 70.46 9..| May 17| 3 3248; 87 1} 65) IO} oe Bt 46 | 11.49} 35.63 | 52.88 10..| May 18| 37 | 20:4} 80! 1], 41} 2%] 36 19 | 31.25] 45.00] 23.75 11..| May 19| 39 | Te Oe a ae ee are ae 51 | 21.25 | 24.21 | 54.54 12..| May 20| 37 | 73¢ | Oe Met o1964 Sif Wee 51} 8.12} 41,93] 54.95 as SS ee a ee Total 2 Sb9r| 2. ess ea ok eee ples LES 178 232 39.8) Pe eee eat Se eos = ae Ayerage|...... 1 ne ETE 5 Ts eae Fae bas shah | 27.12 | 382.05 /| 40.89 Poison sifted from a sack.—-Five tests (Table I, Nos. 6, 7, 8, 9, 10) were made at Victoria on seppa plants without squares. In tests 8, 9, and 10 the plants were sprayed lightly to give dew conditions. The total number of weevils used was 371, and the average time before making the last examination was 42} hours. The number of live wee- vils found was 24.69 per cent and the dead 25.33 per cent of the total number treated, while 49.69 per cent were missing. In three of the tests the exact amount of poison used is recorded and was at the rate of 20, 33, and 45 pounds per acre, respectively, where plants are 2 by 4 feet apart. Two tests (Table I, Nos. 11, 12) were made upon seppa plants bear- ing squares. In one test with 95 weevils on 39 plants the last exami- nation, made at the end of 96 hours, showed 21.87 per cent alive, 24.21 per cent dead, and 54.54 per cent missing. Poison was used at the rate of 41 pounds peracre. The second test was made upon 93 weevils on 38 plants. At the last examination at the end of 96 hours 3.12 per cent were alive, 41.93 per cent dead, and 54.95 per cent miss- ing. The rate of poison used was 73 pounds per acre. Wherever the poison was applied so heavily the plants were very badly injured. 211 it These results are abundantly corroborated by Professor Sanderson, who states: We have made similar experiments with over 500 weevils and were unable to find over 30 per cent dead at the end of 4 or 5 days, while an average of about 9 per cent were found alive at the end of 5days. The balance of over 60 per cent were missing. About 10 per cent of the marked weevils recorded as missing upon examinations of treated plants were subsequently found alive upon other plants. A careful series of tests has shown that weevils are incapable of flight after having eaten Paris green. It has also been found that on the average one ten-thousandth of a grain constitutes a fatal dose. It would appear fairly certain, therefore, that nearly all of the missing weevils really escaped alive. If so, then the number of _ weevils actually found dead approaches very closely to the total num- ber killed, while the number found alive is really less than one-half of those that actually escaped. The period of the emergence of the weevils from hibernating quarters is known to extend over from 6 to 10 weeks, so that at least four applications of poison would be nec- essary to keep the cotton poisoned thoroughly enough to kill as large a percentage of weevils as was killed in the foregoing tests. Summary.—Summarizing all of the tests with dry Paris green on small areas gives a total of 732 weevils used. Theaverage time between treat- ment and last examination was 54hours. An average of 27.12 per cent of the weevils were found alive, 32.05 per cent dead, and 40.89 per cent missing. The lightest application of poison was 20 pounds per acre, and four applications at this rate could not possibly be profitable, especially since the last applications would be after the cotton had squares, and the number of weevils the poison would kill would be greatly reduced. No tests were made with very light applications, but the following experiments made on the Government farms and by individuals show the inefficiency of Paris green where the poison was applied at a rate of 13 to 3 pounds per acre for each application and used throughout the season. TREATMENT OF LARGE AREAS DURING SEASON OF 1904. _ Three experiments were conducted by this Bureau at different places, using Paris green on one plat and making frequent applica- tions throughout the season, keeping an adjoining plat as a check, both plats being planted at the same time with the same kind of seed and both cultivated exactly alike. Field experiments at San Antonio. At San Antonio a field of 1.70 acres planted with King cotton was chosen. This field was compara- tively isolated, there being no nearby cotton except on one side and this was separated from the test fields by a dense strip of sorghum 124 211 12 feet wide. One-half was kept as a check and, beginning when the first squares were formed, Paris green was applied by means of the sack- shaking method on the following dates: Pounds per acre. June LOM Sess PE Ee. Je Oe eres 1 DUNG Gs Be ek he 4 Ae ee ie fee es ee ee 1} UG ae ee et ae LS Se ee Se ara et eee ps 1} jc ars eel ee lp oh pte nly aint ley Sah ape gt) Gt ba gagates Boe SV yt 1} PUby Ho Sree LENTIL Cs eee. BAe ene bee Sennen dae eee 1} pMURbE 2): 2. 2h0etss Reet eee See od. see Shee ee 1} From July 13 to August 3 examinations were made to ascertain the relative number of squares infested on the poisoned plat and its check. Blooming ceased before the first examination was made, and at practi- cally the same time on both plats, so the table does not show the rela- tive infestation while blooming was in progress, but it does show most conclusively that the poison did not kill enough weevils to allow the | treated plat to keep on blooming and producing bolls after the untreated check had stopped blooming. TaBeE Il.—Evaminations of Paris-green experiment, San Antonio, Tea. Number | Number | Number /Per cent Plat Date ex- jofsquares} Number | Per cent | of small | of small | of small ane amined. | exam- | infested. | infested. | bolls ex- | bollsin- | bolls in- ined. amined.| fested. | fested. PATASPLCCW 2. = tien x seciaccics sane | July 13 78 70 89. 74 3 3 100.0 Beth trance se Leese of ci ce adOs cs 93 87 93. 54 0 0 0 IRATISO TRON) 24 2=chitoe esto eke July 27 91 76 83.51 5 2 ; 40.0 AGH EOK soca. oe cence see pusneee ae dO Se 90 78 86. 66 8 3 37.9 Parisiereen.. cs... leeds. | Aug. 8| . 88 85 | 96.59| 10 3 30.0 (GLiett) ee aes Oks Sele eee eerts Coy see 69 61 88. 40 10 4 40.0 An average of all examinations on Paris-green plat shows 89.94 per cent infested and on the check 89.53 per cent. The fact that the percentages are almost identical shows that the poison had practically no effect. The poisoned area yielded 190 pounds and the check 93 pounds of seed cotton, an increase on the poisoned plat of 97 pounds, which would be a gain of 113 pounds per acre. The cost of poisoning was about $1.80 per acre, so that, making no allowances for the *circumstances noted in the following paragraph, the net gain was only about $2.15 per acre, reckoning seed cotton at 34 cents per pound. Running diagonally across the poisoned plat was an old road, the presence of which was not known when the experiment was planned. This road touches only one corner of the check plat. Along the loca- tion of this old road the cotton grew very rankly arid produced much more abundantly than did the adjacent portions of the field. Making an allowance for the increased production on the Paris-green treated 211 13 plat due to this old road, it will he seen that the real increase, if any, due to the treatment would not have paid for its application. It did not lengthen the period of blooming, increase the number of blooms, or produce any marked increase in the yield. Field experiments at Mexia.—A field of 1% acres in the form of a right-angled triangle was divided into a l-acre plat for poisoning and a one-half acre plat for check. On one side of the field, but separated from it by a gully 20 yards wide, was another cotton field; the other two sides were adjacent to a peach orchard and to farm buildings. Beginning immediately after the first chopping an application of Paris green of 1 pound per acre was made from a sack on each of the following dates: May 16, 24, June 8, 29, July 8, August 4. From July 30 to September 13 five examinations were made to determine the relative number of squares infested on the poisoned plat and on the check. Tasie III.—Evaminations of Paris-green experiment, Mexia, Tex. Number Number | Number | Per cent Plat Date ex- jofsquares|} Number | Per cent | of small | of small} of small ate amined. | exam- | infested. | infested. | bolls ex- | bolls in- | bolls in- | ined. amined. | fested. fested. ; ——— ns PAIS OMCEN ee tena a tlecints = in July 30 58 50 86. 2 31 25 80.0 (O17 (ae) ARO: Se ee Se eee ae wae dol ..! 60 52 86.6 20 16 80.0 Panis greet -....-..s.+..-.---- Aug. 9 28 24 85.7 62 | 52 83.8 MOCO) RARE 3 See ees 5 ose feat Corre] 22 19 86.4 43 37 86.3 EAS PSCC pial min afsinimaisinin a etn) siar=l= Aug. 16 10 10 100.0 40 39 97.5 Cheeta ocekee nec acesic as OO) n. 12 12 100.0 50 50 100.0 Paris green .........2.------+5- Aug. 29 80 72 90.0 18 | 18 100.0 CREO RA SM ate Sache ee hes seh. dors: 77 74 96.1 42 42 100.0 Parisereen ...-.:teslizs<.v2es2 | Sept. 13 | 134 125 93.1 12 11 91.6 ChOGie ie San ae oe eee See See ee 8@eeg| 102 94 92.1 16 16 100.0 An average of these five examinations shows that on the Paris-green plat 91 per cent and on the check 92.2 per cent of the squares were infested. The fact that the percentages are almost identical shows that the poison had no effect, and this conclusion is borne out by the yield. The poisoned plats produced 270 pounds of seed cotton, while the check, which is only one-half the size of the poisoned area, gave 200 pounds, or an excess of 50 per cent over the poisoned area. Field experiments at Calvert.—An isolated 5-acre field was divided so that one-half of it servedas a check. The entire field was planted dur- ing the third week in March, but growth was delayed by unfavorable weather conditions. Beginning immediately after the first chopping, May 26, applications of 1 pound of poison per acre were made every seven days. Fifteen applications were made in all, the last being on August 31. The cost of the poison used was $6.20 and the labor $10.80, making a total of $17. The method of applying the poison 211 14 was the usual method of sifting froma sack. Early in the season three examinations were made of lots of ten plants in each plat to determine the number of weevils. Taste 1V.—Number of adult weevils found, Paris-green experiment, Calvert, Tex. | Number Plat. | Date. of / weevils. | PEPIS ORC OM case oar. aoe aie selene op asmiw nie. = Se me wi aplotmtmiesa loin sie l ea ein nie jo miele mw iam) nl alniereimt= pga =i=) July 21 0 (Rijs t) Seek ye oe pee ee eS Sees ste 5 2 Se ine FS RE ie eee oe Sd SRR EP eR p-sdo So33 0 Parisi@reemi 225 02. oe. bOee < Sie soc c ann ain «oie deine whims <= nial reentns Sen era lelmehw am Aug. 4 0 PTC) an ee ie pee Re ae SI RI UE Socios BASIS oe no SA oak ee ssp iGcee cp or See eons 0 PAFIS'PTCOM cpg acne coer w gee Seciom lacie Solem eae ee eet nos qe Wawa si acige 2 = ee ae ee ena | Aug. 15 16 CGE es oe ee eae Bi cere sas date ewawae here twa ie ean ade nat nteapelte= a a aetaes Fes OY 2 18 Later two examinations were made to determine the relative numbers of infested and uninfested squares and bolls. TasBLE V.—Jnfestation of squares and bolls, Puris-green experiment, Calvert, Tex. rf ’ ? a. Number | | Number | Number | Per cent Plat Date ex- |of squares! Number | Per cent | of small | of small} of small : amined.| exam- | infested. infested. bolls ex- | bolls in- | bolls in- | ined. | amined. | fested. | fested. CS ee ae eee ee Aug. 23 128) 124) gn 80 3 2.3 Tn a ee es Seer owas: 133 | 119 | 90. 0 95 5 | 3.8 BaP Tee. occ. aovaecec ust Sept. 9 | 141 | 131| 92.9 | 30 30 100.0 TET TY CLS Se eee ere | te do ....} 102 | 97 95.0 | 34 33 97.0 These examinations show only a very slight difference in percentages of infestation, which was in all cases so great as to prevent flowering. It will be seen that the poisoning had no appreciable effect. The poisoned plat yielded 1,217 pounds of seed cotton and the check 1,070 pounds, which is an excess of 147 pounds for the poisoned plat. Reckoning seed cotton at 34 cents per pound there was a gain of $5.15. The total cost of poison and labor was $17, making a loss of $11.85, or $4.74 per acre. EXPERIMENTS CONDUCTED BY VARIOUS PLANTERS. Mr. J. C. Houston, Floresville. The 2-acre field poisoned was isolated. There was a road on one side, pastures on two sides, anda house on the fourth side. The cotton was seppa and received five applications of poison at the rate of 14 pounds per acre, in addition to which one-half of the field had a fur- ther application of 8 pounds. All applications were made before June 1 and by the sack-shaking method. On June 9 an examination of this field showed that 30 per cent of the squares were infested, and on July 2, when 71 per cent were 211 ~~ | oe 15 infested, the field had stopped blooming. Weevils were so numer- ous at that time that there was no chance of further formation of bolls. As the yield was somewhat less than 250 pounds of seed cotton per acre, it can not be considered that the use of poison was successful. Mr. W. Withers, Lockhart. | Plat 1.1 acre, King. Mar. 22. | Plat 2.—4 acres, King. Apr. 12. Plat 3.—13 acres, Mebane. Apr. 12. Plat 6.—27 acres, Mebane. Mar. 17. Plat 4.—15 acres, King. Apr. 12. - Plat 5.—5 acres, Mebane. Mar. 17. The above sketch, with the exception of plat 6, represents the fields which were poisoned once by means of a powder gun at the rate of 2 pounds per acre. With the following exceptions, the fields were all cultivated exactly alike, each being plowed nine times. Plat 1 was broken four times, as follows: In July, in August, and in September, 1903, and in February, 1904. The other fields were broken only in the spring, when plat 3 was double bedded, while plats 5 and 6 were single bedded. The yield upon plat 6, which was not poisoned, as well as upon the remainder of the plantation, averaged about one-half bale per acre. On plat 5 the yield was about the same; plat 3 gave three-fifths bale per acre; plats 2 and 4 about 340 pounds of lint per acre, while plat 1 produced over two bales. In other words, plat 5 was no better than cotton which was not poisoned, while plat 3, which was double bedded, was better than either plat 5 or cotton which was not poisoned. This difference in yield can be attributed only to the better preparation of the land before planting, for plat 3 was planted nearly a month later than plat 5. The value of thorough preparation of the land before planting is more strikingly shown in the contrast between plats 1 and 4. Plat 1, while only 1 acre in area, was thoroughly broken four times before planting and produced over two bales, while plat 4 with one spring breaking produced less than four-fifths bale per acre. Mr. Withers also poisoned a 5-acre field six times at the rate of 2 pounds per acre for each application and this field did not produce as 2U1 16 much as did fields which were not poisoned. When these facts are considered it becomes evident that the increase in production in the plats mentioned above was largely the result of increased cultivation rather than the result of poisoning. Mr. J. Zachary, Lockhart. At one end of a 10-acre field on the plantation of Mr. Zachary about 30 rows were poisoned from six to eight times by Capt. B. W. Mars- ton; the rest of the field was used as a check. Otherwise conditions were the same in the two plats, each having been planted at the same time and with the same variety of seed. Mr. Zachary states that the check produced more per acre than did that part of the field which was poisoned. In addition to the 30 rows treated by Captain Marston, Mr. Zachary himself poisoned some cotton, treating it about five times. In this experiment also the nonpoisoned cotton was the better. Mr. J. T. Shanks, Cuero. The area poisoned was in the open field with a road on one side and cotton on the other three sides. The fields were planted early in March and were thoroughly worked. Plats of King and native varieties were poisoned by dusting from a sack. The King cotton was poisoned five times at the rate of 1 pound per acre for each of the first three appli- cations and 24 pounds each for the last two. The native cotton adjoin- ing the King was poisoned four times at the same rates. Near by this plat was native cotton poisoned three times and also some poisoned only twice. The King cotton produced about one-half bale peracre. The native cotton poisoned four times produced about the same. The other cotton poisoned did not show any difference in yield between that poisoned twice and that poisoned three times, nor any material difference over cotton not poisoned. As there was nocheck for the King cotton, there is no way of telling whether that variety was benefited by the poison- ing. But in the native cotton the fact that cotton poisoned twice or three times did not show an increase in production over cotton not poisoned at all indicates that the greater production by the part poisoned four times may have been due to some other agency than Paris green. According to a recent statement made by Mr. Shanks in the presence of the writer (November 26, 1904), there were two neighboring fields planted upon exactly the same kind of soil which were not poisoned, but which produced as much cotton per acre as did the field in question. There is, therefore, no doubt that this experi- ment is absolutely inconclusive. 211 Be Mr. W. D. Keyser, Marlin. These fields were visited on September 9 by Mr. G. H. Harris, who reports as follows: Mr. Keyser had twice poisoned a 24-acre block at the rate of 23 pounds per acre. The adjoining nonpoisoned field ap- peared to be equally well fruited, but no blooms were seen in either field. Another 20-acre field was poisoned twice with a half pound per acre at each application. The adjoining field, though not poisoned, appeared to be equally as good. In another field one part was poisoned twice with 1 pound per acre, one part four times with 13 pounds per acre, and the balance was not poisoned. No difference was found in the number of bolls or blooms on the plants counted, and as many weevils were found in one part as in another. The fact that Mr. Keyser’s crop is better this year than heretofore is due to the fact that this year he has planted improved seed—King and Indian Territory mainly. Other near-by fields were seen which, while not poisoned, were as good or even better than Mr. Keyser’s poisoned fields. Rev. J. M. Purcell, Lockhart. All of the cotton used in the following experiments was planted in rows 40 inches apart, with plants 2 feet apart in the drill. All fields were plowed four times. All were poisoned four times by means of a powder gun at intervals of ten days. The first application was made on July 18 and the rates of application were 2, 2, 2, and 6 pounds per acre. Each of the four experiments had an adequate check. In two of the tests the poison was applied early in the morning while the plants were still wet with dew, and in the other two the poison was put on after the plants had become entirely dry, the theory being that the poison would enter the involucres of the bolls and squares. The first field, about 25 acres in area, was located on a hillside and the part poisoned was a triangular piece of one-half acre. This field was planted early in March with native seed, but replanted after being cut down by hail on May 16. ‘To this field the poison was applied while the plants were dry and the yield was nearly 700 pounds of seed cotton, while the check produced almost nothing. All of the following fields were entirely cut down by the bail on May 16 and were replanted with common native seed about May 30. The cotton was about waist high when first poisoned. The second field was located on bottom land with woods and creek on two sides, the land sloping upward and away from the creek to the northward and at this end of the field was the check; the southern end of the field was 1 acre in area and was poisoned when the plants 211 13156—No. 211—04——2 18 were dry; lying between this and the check was one-half acre sepa- rated from these two plats by strips 30 feet wide, and to this area the poison was applied while the dew was on the plants. The yield of the 1l-acre field, poisoned when the plants were dry, was nearly 1,000 pounds of seed cotton. The field poisoned while wet with dew gave about enough to pay for the cost of the poison, while the check produced almost nothing. The other field, which was poisoned while wet with dew, was also on bottom land with woods and a creek on one side and corn on one side, the nearest cotton being about 100 yards away. The area of this field was about 14 acres and the part poisoned was in the center of the field. The result of this test is identical with the other test in which the cot- ton was poisoned while wet; that is, the yield will about pay for the cost of the poison. These results show failure in both tests where the usual method was followed of applying the poison when the dew was on the plants, while both those tests in which the poison was applied when the plants were dry were apparently successful. These are the only instances of even apparently successful use of Paris green known to the writer. When considered in connection with the great number of unquestionable fail- ures, it would seem that some other agency than the poison may have been responsible for thisapparent success. Mr. Purcell is not inclined to accept the results as a conclusive demonstration of success in poi- soning while the plants are dry and says that the experiments must be repeated next season to prove an actual demonstration. Planters at Hearne. A number of large planters living around Hearne poisoned all of their cotton two or three times this season for the leaf worm, but they are unanimous in stating that it is ineffective against the boll weevil. Among those who have used Paris green extensively may be men- tioned Mr. C. G. Woods, who poisoned a 20-acre field five times, using 24+ pounds per acre at each treatment, the first application being made when the cotton began to square. The yield of this field was no better than that of fields which were not poisoned. Mr. Woods also poisoned about 300 acres twice during May and June at about the same rate as above, but says that the yield is no better than that of other cotton which was not poisoned. Col. R. J. White poisoned over 2,000 acres three times for leaf worm, beginning about July 20, and using 14 pounds per acre at each application. He says that the poisoned cotton has yielded no better than cotton on similar lands which was not poisoned, and that Paris green is of no use in fighting the weevil. The tendency in this locality is to drop poison entirely, for in the presence of the boll weeyil the 211 19 leaf worm is considered a friend instead of an enemy, and planters who have several thousand pounds of poison on hand at the present time declare that they will not use another pound of it. SOME REASONS FOR APPARENT EFFECTIVENESS OF PARIS GREEN. There are several circumstances which have led some users of Paris green during the growing season to conclude that the applications of poison were effectual, but upon closer examination it may he seen that these appearances depend upon other causes than the application of poison. The active life of the hibernated weevil may extend over from 60 to 80 days, so that during the latter part of May and during June a majority of the weevils which lived through the winter, having by that time deposited their eggs, are dying naturally, and these dead weevils being found in the poisoned fields have given the impression that they were killed by the Paris green. SS ee Stone HROMEIIRO Mt eee ee 15: to:205)\\- Wan Fandite= See eee eee 20 to 25 Acomntrartinee em sae Bees ow ta 50 to 60 In pleasing contrast were the much less serious ravages of the insect in 1904, when it was only more or less locally that severe injury oceurred. The favorable weather of the fall of 1903 and the follow- ing winter and spring permitted very general breaking up of land during this period, and many pup were undoubtedly thus destroyed. The moths were noticeably much less numerous in young field corn during the spring, and they were subsequently much less abundant, as evidenced by the number of eggs on the silks of early and late corn. The cotton crop was, on the whole, planted at or before the normal date, and in most fields a fair crop of bolls had so matured by early August as to be exempt from bollworm attack in the presence of an abundance of more tender bolls and squares. While complaint of injury came from a considerable range of territory, it was not, on the whole, of serious extent, except on late cotton on bottom lands. In the accompanying map (fig. 1) the shaded area marks approxi- mately the territory infested in 1904. The average annual injury to the cotton crop of the South, mostly confined to the western part of the cotton belt, is probably not less tham $11,500,000. 212 il PLAN AND SCOPE OF INVESTIGATION. The present bollworm investigation has been conducted largely in Texas, in view of the seriousness of the depredations of the pest in that State. The work was begun in the spring of 1903 and has con- tinued to the end of the year 1904. The investigation has been prose- cuted both in the laboratory and inthe field. During 1903 headquarters were established at Victoria, Tex., where office and other facilities were available in the building occupied by the force engaged in cotton boll weevil investigations. Experiment farms were established at Calvert, Wills Point, and Hetty, Tex., covering in all 140 acres. Only one entomologist was engaged in the work. The more important results of the work of 1903 have been given in Farmers’ Bulletin No. 191 of this Department. In 1904, by reason of an increased appropri- ation, the work was considerably enlarged. Headquarters were estab- lished at Paris, Tex., where a laboratory was equipped for the study of ail points likely to throw light on methods of control. Four entomologists were continuously engaged in the investigation, and a fifth during the summer and fall months. In the field, experiments were conducted largely along the lines followed in 1903, as follows: (1) To determine the possibility of mak- ing a crop of cotton before the period of greatest bollworm injury, by the early planting of early-maturing varieties of cotton, aided by fer- tilizers and by thorough cultivation; (2) to determine the value in bollworm control of spraying or dusting cotton with arsenical poisons; (8) to determine the value of corn as a trap crop in protecting cotton from bollworm injury. In the prosecution of this work it has been necessary for the Depart- ment to have control of numerous tracts of land, along with labor and farm equipment. These have been secured by means of contracts with planters whereby the planter has been guaranteed a satisfactory yield of cotton in return for the obligation assumed to carry out the Department’s instructions as to the growing and handling of the crop. In the course of the investigation, experiment and demonstration farms have been established as follows: Experiment farms used in work with the bollworm, 1904. ete 5112 . . | Number Location. Plantation of— res FRIIS sO sein ae bs ao, 2) «tas meree Rise cBOD MORE 5... cc ceo Sees 40 | eA NOX 5a cnsec dc 3 See Ea CEO Mies 3. ck a Scena nee | 100 | FIRED ETE e ioc ons no. ce ee FGaptebee. Wikkom) <2 cade ssl oceex 30 | Sulphur Springs, Tex ........c2.5. FROME the 4 ELIOT O WO ss c.2 seis 2 oe cnc | 50 | Tali ie nh sc. es ae ah eee ne ee fa Fey 51 eto] 0} 0 Re a ee 40 WSR orm LOX... as si cancae eee KEE nae Ney ALLO, arses era a cee 50 WAGE peer fc: 2 aio a/s > sic tacee sects Ob pI MLSODS 2/0) oe his oa eeae oe 40 SHREVE PONG Wal so. 2 oon even cet oeee EVIOROWY cli BOSUCT 52 panes ce cm eee ae | 40 it) fj 0101-40 le ADS 6 ee a a Captel. Lb; Maxwells s445. 0-22.68 55 Ghar ewe os. oe tobe Jie Gini eee oom: Yes oie 30 Neri yell EN 35 RS ee a ee Sea Demonstration farm of E. H. R. | 15 Green, 212 12 In addition to the 490 acres represented above, numerous smaller areas have been utilized in cooperation with planters, increasing the aggregate to about 600 acres. On these farms tests have been made of every expedient likely to be of value in circumventing bollworm injury. The scheme as to cultural methods has included the comparison of early-maturing varieties of cotton from the more northern States with local varieties, and of early with late planting; a study of the effect of fertilizers in increas- ing the crop and in hastening maturity; and a comparison of average cultivation with thorough cultivation under all of the above conditions. Such work, as will at once appear, bears directly on the bollworm question in its relation to the production of an early crop. The accompanying diagram of a 48-acre field will serve to illustrate the method followed in the solution of the several questions involved. The methods of treatment enumerated have thus been brought into comparison under the uniform conditions as to soil, etc., which are necessary in experimental work of this kind. Experimental cotton plats of the Department of Agriculture at Ladonia, Tex., 1904. Fists; Plat 2. Plat 3. Karly planted. Early planted. Early planted. Early variety. Early variety. Native seed. Thorough cultivation. Thorough cultivation. Thorough cultivation. Fertilized. No fertilizer. No fertilizer. Plat 4. | Plat 5. Plat 6. Early planted. | Early planted. | Early planted. Jarly variety. Early variety. Native seed. Average cultivation. Average cultivation. Average cultivation. Fertilized. No fertilizer. No fertilizer. Plat 7. Plat 8. Plat 9. | Late planted. Late planted. Late planted. Early variety. Early variety. Native seed. | Thorough cultivation. Thorough cultivation. Thorough cultivation. | Fertilized. No fertilizer. No fertilizer. | Plat 10. Plat 11. | Plat 12. Late planted. Late planted. Late planted. “arly variety. Early variety. Native seed. Average cultivation. Average cultivation. Average cultivation. Fertilized. No fertilizer. No fertilizer. Experiments designed more particularly to test the effect of several classes of fertilizers were conducted on the principal types of soil of north Texas, and the plan and results of this work on two of the typ- 212 13 ical soils are detailed on a later page. Owing to complications which would result from the presence of the weevil, these experimental farms were as much as possible located in sections comparatively free from this pest in Texas. One feature of the work has been the comparison of varieties of cotton with especial reference to their earliness, prolificness, and quality of staple. In all, 75 supposed varieties of cotton have been compared during the past year. In the case of insects attacking staple crops, the margin of profit in their cultivation does not often permit of the employment of remedial measures other than those involving changes or improvements in farm practice. However, the readiness with which cotton may be poisoned with Paris green or other arsenicals, particularly in a dry form, by means of poison blowers or the primitive but effective method of bags suspended from poles, has placed this operation among those which may reasonably be employed. Considerable attention has been given to the matter of testing poisons in bollworm control, both in 1903 and 1904. In all cases the plan has been to measure off, say, 20 acres of uniform cotton, 10 of which would be poisoned and 10 left as a check. The efficacy of the treatment has been measured by the yield from the respective areas. No rational plan may be formulated for the control of an insect except as based on a thorough knowiedge of its life and habits. The importance of life-history studies is therefore evident. The labora- tory investigations of the past two years have covered all important features of the biology of the bollworm, confirming many points already known and enlarging our knowledge of the species. The determination of the number of generations was effected by the use of a large breeding cage in which corn and cotton were grown exactly as in the fields. These observations were checked by rearing experi- ments in the laboratory. The destructive capacity of individual boll- worms was determined repeatedly by confining a larva on a cotton plant under a wire cage. The efficacy of poisons was determined in a small way by the same plan. The effect of the destruction of pupal cells, as would be accomplished by plowing, was determined both for Jow and high temperatures. The length of life cycle and the number of stages has been determined fora large series of individuals cover- ing the entire season. The effect of food on the life and egg laying of the moth, the number of eggs deposited by a single female, conditions which affect their vitality, and many other points have been investigated. Especial attention has been given to the study of the parasites and predaceous enemies of the bollworm, especially as to their value in keeping this pest in subjection. It has always been a pleasing propo- sition to import from foreign countries the enemies of a pest and array these against it in the hope of lessening its destructiveness. Early in 212 if the present investigation many foreign entomologists were corre- sponded with in countries where this species was known to occur in the hope that important enemies of the bollworm might be discovered and imported to this country. No important enemies, however, have been discovered. SOME RESULTS OF FIELD WORK. Attention has elsewhere been called to the principal lines of field work. Of first importance is the so-called cultural method, which consists of the employment of all such means as will contribute to the production of an early cropof cotton. This involves especially, (1) the use of seed of early-fruiting varieties; (2) early planting in the spring; (3) early and thorough cultivation; (4) the use of fertilizers to hasten and increase the growth of the plant and the development of fruit. As has been stated, the cotton crops of Texas and adjacent States have, until recently, been largely produced from native-grown seed, often secured from public ginneries and of unknown variety and origin. The accumulated effect of the climate has been to make the crop later and later in maturing, especially in the absence of selection of seed for earliness and other qualities. During years of severe bollworm injury, the insects, upon their migration from ripening corn to cotton in early August, have found but few fields in which the bolls were sufficiently matured and hardened to be unsuitable for food, and practically all of the fruit has been subject to attack. The importance of early planting to avoid bollworm injury has long been recognized by planters, but sufficient attention has not been given to the matter of using improved varieties of seed and to the adoption of improved farm practices. Many observers have noted that relatively less Injury was done by the bollworm and other cotton pests, espe- cially the leaf-worm, to early-planted than to late-planted cotton. Thus Riley, as early as 1885, says: Our knowledge of the natural history of Aletia [Alabama argillacea] and the yearly occurring experiences with its ravages, teach us that the principal and most effective means of prevention is to hasten the maturity of the plant so that a portion of the crop shall be beyond the reach of harm from the more destructive July and August broods of the worm. * * * Improving the cotton seed in the direction just mentioned can be accomplished principally by careful selection of early varieties of cotton or possibly by introducing seeds from more northern regions. Early planting is to be strongly urged in this connection, although of course it has its drawbacks in the risks of exceptionally late frosts. Professor Mally, in discussing certain statistics of the comparative injury by the bollworm to early and late cotton in Texas in 1892, says: The late cotton, therefore, shows a loss of 50.6 per cent, while the early cotton shows no real loss. This may be taken as 4n extreme case, but the general principle remains that late cotton receives by far the greater portion of bollworm attack, vir- tually protecting the cotton fields about it. 212 | POSS kc al We Re SST a de doy aS | Neate BL 2S set aabes (CO ces) Gea bale oa carl so coe CUA TO | quod Jod osvidAy 16s | 922 | 00 | GE | LPL | S89'L | G6 | 1G 29 LOL |-G9& | SSR 1-89 — Po" =o [vIOL “UIO}JOY IOATY poy “Sulatoyy | z sure 18 | 98 | 88 | 29 | ZL | ado L9G | 0 I 8 8% 18 GPP NOD Seiwa aeaee ye JUOTITY | 1g ‘sny fonvad “yourg “Upydajog | [ Aviy Of | 0¢ | #8 | 02 | Ec | Ofte LE. | 8 L IL ae Lo ie Si codl a? Sec. Ae tats Std | 2a “SNV ‘oldreid “ARIF “UopMOY | G ALT 98. | 18 | OL | G& | 6G | 16 SOL | T 9 8 13 tg SL UG. Sl Speen JUIOd ST[ITM | GL “sn yw “yeo-ysoq “TOW Biq | cz dy oF | SG | Fe | Ub | OSE | $8 eg | 0 P OL 8 6c id 3) Sagi |e uvpumM? | cE “sny *POPOOM “AXVA-YORBl[Y TWPH | GE ‘adv Bee 9) 8 Ob a tee. SBE) ee (5g hE | SG | 9¢ | OL |°7-° UlpyUueIg Usg | IT “Sny “‘popooM “AXBM-YORB[G “sui | G AVI Eaten Cee eu. IeDPasiatea: siKOocO | sco Geresise GUE Pe Olea seers BuOpvy | 6 “sny ‘NOLLOO GALNVTd-ALVI OL AUNLNI EN NA TS CHS A eli SI Tt lH en eS me Pact a NG hl esgic hE ag Aanlut jo quad ted o8RIdAW ‘es CLL‘ | #&h‘S [SCOT] TFS | G4% | 948 | ISL | OT | LPS | 6 8 ce 8g cor | 99 c9 ces POL OE es | | eee = | | SS | ——————————————— "107109 JOATY Poy “SUTM | e% “IVIL | 9° | 86L | GGL | Ok | CL | #9 | 9% | Eat | 4G Grate ee = lag 8 Lz p OL mad ie juowmpy 1g ‘sny ‘oyarerd “HOV [10M SIM | OF “AVN | L°6T | 87s | EBT | BL | IZ | OL | et | ee | CTE a a a aa) Se a 6/8 ete (Meee ree ioe sued 7 ‘Sny ‘oMTeid “AVIN) “BUIM |*--Op-"-"| 6h | P4a‘T | TIs‘T | 468 | v8 | 98 | ThE] OFE | G9E |e9 10 jo | 0 6 68 | GE |.0¢ JULOd STA GT “sny 10 ; e NboW0d “SUI | T ‘adv | g'¢ | cLz Kira gor |} €L | 8 G |99 16 cl | FP (é T g g 0 OT Safes ee uvjuingy zi ‘sny | {PEPOOM “AKUM-YOBlT “IIBH | 66 “AVIN | 9°¢ | 619 FSS &@ | OF | TG | 88 | 64. | SOs ce | 0 0 P G OT SL OL ““"" UlYUBIY Ue TL “sny ‘popooM ‘AXVM-YOVl “SUIM | LT “Ady | 9°ez | PSG GFP 69 | e& | 4 | SOL} IST | so 8&E | & G LT 1G 9S 1s OL (ie aay > CFHOPB T= 6. Say: = on | Fe 3 , 300 pounds per acre. Cultivated 8 times. Hoed 4 times. Yield, pounds seed cotton per acre, 995.6. Plat II. Five acres. Planted March 30, King seed. Unfertilized. -Cultivated 8 times. Hoed 4 times. Yield, pounds seed cotton per acre, 736.4. Plat V. Five acres. Planted April 1, King seed. Untertilized. Cultivated 8 times. Hoed 4 times. Yield, pounds seed cotton per acre, 765. Plat VI. Five acres. Planted April 1, King seed. Fertilized, R. A. P.°, 300 pounds per acre, plus dressing of nitrate of soda, 100 pounds per acre, when plants had 4 to 6 leaves. Cultivated 8 times. Hoed 4 times. Yield, pounds seed cotton per acre, Plat VII. Five acres. Planted April 1, King seed. Fertilized, A. P. & P. M.¢, 300 pounds per acre. Cultivated 8 times. Hoed 4 times. Yield, pounds seed cotton per acre, 831. PlateeVve Five acres. Planted March 30, King seed. Fertilized, A. P. & P. M.¢, 406 pounds per acre. Cultivated 8 times. Hoed 4 times. Yield, pounds seed cotton per acre, 974 Plat VIII. Five acres. Planted May 2, Rowden seed. Unfertilized. Cultivated 4 times. Hoed 2 times. Yield, pounds seed cotton per acre, 675.4. aC. B. G.—A commercial cotton boll guano; analysis—available phosphoric acid, 8 per cent; potash, 2 per cent; nitrogen, 2 per cent. oR. A. P.—A commercial acid phosphate; analysis—availab!e phosphoric acid, 14 per cent. cA. P. & P. M.—An acid phosphate and potash mixture; analysis—available phosphoric acid, 13.79 per cent; potash, 4.65 per cent. 212 17221—No, 212—05——2 18 More detailed figures are given in the following table: TaB.eE III.—Showing treatment of and results from plats on bollworm experiment farm of Department of Agriculture at Wills Point, Tex., 1904. ; =< 3 See ae sik 3 ao at = Boy |=538 is > iro} q oO Am ly 2.o cS So 2) 8 ren eg f= q Od | at |PBS 2 , S) & 9 |} Sey joao & o seme re R 0) as Ros |\2n4n| 5 Variety of | Fertilizer and quan-| Date of a q palin’ opm joGFH| g = cI cotton. tity used per acre. | planting. & 3 Ze Soa |5o aie] 4 bu 4 3 | 3 | 23 | 2.5 ess! § | 4 é ° HO oi © On’ a =) wy QD a2 ood HD om ay qa ov o Q nDnOoOD |\Os oe aI = = a Zz Sf |\Qs Bs] oO Ea 3 A} Ee] Ss. | Sse Esse] 2 | 3 Ay A | a a ne i> iS) A ee ee (ee a = ae I | N.C. King..} C. B. G., 400 pounds.| Mar. 30 8 4| 986.6! 311.2 | $11.47 |$4.60 | $6. 87 i a) Oe QO o8s5. R. A. P., 300 pounds.}....do.-.|} 8 4| 995.6 | 320.2] 11.81 | 2.85 | 8.96 ED eae GO... 52 Unfertilized......... Oe). 8 | 4| 736.4). 61.0 vss: Ieee 2.24 DIVE Scere dO)\.525= AJ Pand)P.M.,'400)|: ..0do)..5: 8 | 4] 974.0) 298.6] 11.01 | 4.30] 6.71 pounds. Metloan ce dO) -25-58 Unfertilized......... Apr. 1 8 | 4] 765.0 89.6 S:80nleeess 3.30 Af iy |S eee GO. a=c% R. A. P., 300 pounds; |....do... 8 | 4} 852.4) 177.0 6.53 | 5.85 68 sodium nitrate, 100 pounds. SV abet Ld ees A. P. and P.M, 300.|....do... 8 | 4) 831.4] 156.0 5.75 | 3.22] 2.53 pounds, | VIII | Rowden ....| Unfertilized......... May 2 4) 24) NCTA. | a 22] Se tea eet |e Aside from the yields of cotton, the influence of the several treat- ments on the fruiting of the plant was determined by actual counts of all the fruit on 20 plants for each plat, on several different dates during the season. Vigorous, well-branched plants were selected in various parts of each plat. These plants were not marked, and consequently a differ- ent set of plants was used each time the counts were made. The fruit- age was determined in this way five times during the summer, at inter- vals of about sixteen days. The first count was made on June 9, square production having just begun; the last on August 15, when the bolls were beginning to open. The prime object in making these records was to determine the rel- ative earliness of fruit production, (1) with King seed, early planting, fertilizers, and thorough cultivation; (2) with King seed, early plant- ing, no fertilizer, and thorough cultivation, and (8) with Rowden - (native) seed, late planting, no fertilizer, and ordinary cultivation. The records made on plants grown under the conditions named in the last group are used as a basis of comparison. 212 : 19 Taste IV.—Showing rate of fruiting on respective plats of bollworm experiment farm of Department of Agriculture at Wills Point, Tex., 1904. Average number of bolls per | Average increase per plant in number plant. of— Aver- One- age One- jhalf to} pyq. Date of | num- fourth-} three- Open Plat exami- | ber of ei epee grown |fourths| 87)” | polls as number. <= One- | half to 3 as com ~ |DOlls as nation. [squares s5o7th | three- Full- re) da bolls as} grown _ | COom- pen. | pare com ‘ per n.|fourths|StOW2- With | COM: bolls as ared pared plant. 8 Neh Nats pared | com- 18 ith with Stoo plat ©. | “with | pared plat g, | Plat 8. plat 8. bien fi plat 8 I Gare ee Sa ret ects ama se aiepeisiaeel| eiataisin ates Oaple oc oc enlpoee as [estar ss sil ener Il 7G ee a) eee enc ca ae 37 adore 14 tage son) Sbocsmeel| sant see. IIL |. HS ee esa) Sa aereee| soe aate enone. TN ice un Sone) Sn Soee te osesseot aS Sees. — a E Gi, lebee eee (bgas cesclloce doe ss pe secose B86 pea ee Pee ane Oe Rey ee ei VI 438) Vil bz VIII I 8745] af 3038, ay Bt 3455 zo 27 25, 30 IIL 20315 35 1235 20 IV 3235 26 29310} 3 ul 2035 0 1335 35 VI S15 zt Doky fy ot oe 225 20 255 20 Tin Spe eto Se orci aes, etcetera re monies I 1003% Bran 23% ee Gdx% 335 IL 7335 33) Iy|---+-=+- His Ss 38.3; 2a Ill bles 233 Pil scisected| as oench 16 lys AN; 8930 Oz Pt Eee See Defy) day Vit: 4435 250 20|-------- jnnes esse 935, 135) va ff ae Oe eae 20 230 20 BOl-°-- 2 20 {30 20) BOjs+ sce VILL 3535 Tees ean aeed tees ata ee epee OR are oa shee ene Vavanisteticie nape ee is ho ide ood ge ce aa: sti ----d0... Be 235 BOls+see2++ 20) Py al 32] ------+- lesen. 7Gkel Wet OAR Bableo. sous 1433) 2h) BAG] aga howe Cie ear Trees 9933} 1738 gis Bebe 3728 912 618) Teel Scere Wiis. las Ge liunigeter. Gillin | au. as 1 ee epee | eee <3 ales VI |.-..do-..| 82s) = 1935 935 Tif|---+ +--+ 2x5, 1138} 633) 63$)-------- eid cee ol ee ssc ace - SELB 236 2 Dit) DOr ttt eee teeter ee | I | Aug. 15 4 336 835 1235 633, —10%; — 7 30 435 52. 1 fe aa o Pope 1034 1034 85 1635 335| — 8x%rI oo 35 8515 225 IIT |....do.-. 1436] 1d38 835 1435 135 30 433] 20 635 i IV |....do 49 1243 835 1655 cei a ee 36 84, see Vr \,--.00 835 95% Ba'5| 1825 138) — 585] — Iz 10 43 VI |..--do... 1235 1035 935 1535 336] — 238 2 1z5) 136 235 VII |...-do. 248] 98, 826! 18x) 343] —1143] — Igo] 35] Bay] hy ViUI & do 1433} 1032 718 at Tee cl na a eae |rserrees|eessteee The counts made on the several dates plainly show that the plats in the first group, that is, Nos. I, I, IV, VI, and VII, had a decided advantage over the others in earliness of fruit production; those in the second group, that is, Nos. III and V, were about intermediate, while No. VIII fell far behind all the others. Plats of the first group reached their maximum square production about July 9; those in the second group about two weeks later; and plat VIII about a week later than the second. The decided uniformity of the results of the counts on the several dates is noteworthy; also their conformity with the earliness as shown 212 20 by the first picking. The total weight of the cotton picked from the several plats bears out the results of the counts, for it is noticeable that the maximum square production on the unfertilized plats never reached as high as on those which were fertilized, and Plat VIII, which had ordinary treatment, was considerally below Plats III and V, unfer- tilized, but which were planted with King seed and thoroughly culti- vated. The same effects are noticeable in the maximum boll produc- tion. Bolls which are full grown by August 15, as shown by counts of injured and uninjured fruit, are practically safe from bollworm injury; hence the advantage of early-fruiting varieties, early planting, ferti- lizers, and thorough cultivation may be readily seen: for on the above date Plats I, II, IV, V1, and VII show an average of 19} bolls per plant, which would be practically out of danger of bollworm injury. Of these 191 bolls there was an average of 4%; bolls per plant open on that date. Plats III and V show an average of 18, bolls per plant practically out of danger, an average of 1yy of these being open. Plat VIII had 9,8, bolls per plant out of danger, or less than half the number which on the fertilized plats would be quite sure of escaping bollworm injury. PITTSBURG FARM. The experimental farm at Pittsburg, Tex., on the plantation of Mr. J. F. Harrison, was located on atypical sandy soil of that section. It _ was supposed that fertilizers would exert considerable influence on the production of cotton on a soil of this character, and this feature of the work was emphasized. The land used was said to have been in culti- vation contiauously for the past sixty years. In 1902 it was planted: to corn and in 1903 to cotton. The productiveness of the land was considered to be one-fourth bale per acre. 212 a: The accompanying plan shows the treatment of, and the results from, the respective plats involved in this fertilizer experiment: Experimental cotton plats of the Department of Agriculture at Pittsburg, Tex., 1904. Plat I. Five acres. Hetty seed. Planted April 13. Fertilized, R. P. C.@ 300 pounds per acre. Cultivated 8 times. Hoed 3 times. Yield, pounds seed cotton per acre, 1,403.8. Plat II. Five acres. Hetty seed. Planted April i3. Fertilized, C. B. G.4 400 pounds per acre. Cultivated 8 times. Hoed 38 times. Yield, pounds seed cotton per acre, 997.8. Plat III. Five acres. Hetty seed. Planted April 13. Fertilized, R. A. P.¢ 320 pounds per acre, Cultivated 8 times. Hoed 3 times. Yield, pounds seed cotton per acre, 1,202.8. Plat IV. Five acres. Hetty seed. Planted April 13. Unfertilized. Culivated 8 times. Hoed 3 times. Yield, pounds seed cotton per acre, 694. aR. P. C.—A commercial potash compound, analyzing—avyailable phosphoric acid, 10 per cent; pot- ash, 2 per cent. oC. B. G.—A commercial cotton boll guano, analyzing—available phosphoric acid, 8 per cent; potash, 2 per cent; nitrogen, 2 per cent. eR, A. P.—A commercial acid phosphate, analyzing—available phosphoric acid, 14 per cent, 212 22 The comparative earliness of the crop, the increase and value of the same, and the net gain by the use of fertilizers are shown more in detail for the respective plats in the table below: Taste V.—Showing treatment of, and results from, plats in Department of Agriculture’s - bollworm experimental farm at Pittsburg, Tex., 1904. a Ss Weights of seed cotton |v..| 2, ® picked— a> e : =) 3 rs S8\ 3s f= n om ogo S PALCiG mes ties = 3 3 a5 |23 | 8 =] ° Pe] 5 Ho 3 Qa. Ad _O | 22 Bo S} 2 Boa] Oo iy : ae P : Bs 2 | on@|] og a bev dice SB lec| Bee ol tl eameel ee alee ee £ og a + Ee Sa ee el ete tg er |e el af rs} qa 3 eee Ss I'am 400 lio Sule pa 5 rs = q = = 3 8 ~ an a eS Sa ei | 2 os g = Be | ee en ad op AS EA Bi mk i aon nee ui a © 5 = Ain a) oh R eB ba Bl So) Se eee hee bale . o oH “=| Big 8 Ss |[alsje |2)/8/8)2) 8 /s8iss|s) & =|) 8 5 2 [8] See) ery Be ele eters | | ee tes Fe Aa Bla] & ate foam oun to Stee 1 | Hetty. {200 pounds. apr 13} gs) 311,403. 8 148, 6/358. 81397. 4375. 61123. 4 709. 8:$23. 53 $3; 23/920. 30 Y R.P.C. / | | | II |. do. fa }..-do..., 8} 3) 997.8158. 6 340. 61266. 4162.2, 70.0303.8 10.07| 4.60) 5.47 C.B.G. | | TIT |...do ..|{220 pounds. |t_go_..| gs! 311, 202.8 282. 0.499. 0/307. 2125.8 38.8508.8 16.86] 3.04) 13.82 R.A.P. | TV |-::d0 Um Aan eel i sae:.2| 8} 3) 804.0)... Ja77. 0]... Mave) Beale 2 Sette ere ieee Average price per pound lint cotton...........--... 1144) 10%! 10, 9441 94,|. 2... | is cae feat Plats I and IV are compared graphically with respect to earliness’ and yield in figure 2. 2 : 9 MH UL Coe i ye 23-28 WUT rand NO 13 HIN TT ENS —— BEG co 5c ae aa sy N ts} Q = * — Lisa 24 Sis il NM a a Popa =a aes = Fic. 2.—Diagram comparing Plats I and IV of the Pittsburg (Tex.) farm, fertilized and unfertilized, respectively, with regard to earliness and yield of seed cotton. PRICE PERLE LINT COTTO! ON DATES OF PICKING | In connection with the above results as to final yield should be considered certain data relative to the rate of fruit production during 212 a 23 the season as determined by counts on different dates on 20 plants on each plat. The important results of these counts are indicated in the following table: Taste VI.—Showing rate of fruiting on respective plats of Department of Agriculture’s bollworm experimental farm at Pittsburg, Tex., 1904. 5 Average number of bolls per | Average increase ee plant in number Pa plant. of— n o | ; mn i 1 5 Z a a. 23 g 3 3 re ‘0 el | EVE 3 = a aI = 2a aS oy = z ah iS us} oF Veg me g : Rt B fea ty cer te oe : = os ej EB a. | gu | os eee | Sees & oS Es Rd a sd (| He, = Ay ne = 2A 5 SE =i Ga” | eke lec ao 5 E E 2 Bhs aR oo. | be | ao) oemn ee 3 z a | Sh | g an | a¢ |S8a |) oF lee FI S) = ae S a ee lee Br on ool © at = (s) n oc mse ov as E S = 5s | 3 é i om | Seq | ee =) n s = a 0 a =| Seal SoH ons a o HH 7 7 ao = 3 7 ) 2S ay i= + o o o = ) 3 oOo Bet = 3) = A 4 6 |6 é thet ak Oa ho a Ic) ‘ wh io) Y- | 2 | t iz |" u % | I | June 24 Zuo eee [ee aes oka ese eee liv 3 Scr Le eee REE ene es! Pee ese ED, (22.0): he ease selene eel teense eh el eraicial wich win' 6. oe ial Soe ae esse < TL Ser Cote Dh oo ania ee ee ere ees a ares Wood e |Sl nec eee 11) el ae es fissile SEPT Rend RE RR | ee oie Le eel 8 te ee ey Le | I| July 138 6255 256, 135} BU|---+++-- 1635 30 1 ~ Bol-------- Eby 3306) tc 13d 485| 15) seem clei 2744 2 135) es Peewee TEE) ac do . 6134 435) Le oeepicnea eaceenee 163, 2 | AT Reon Vo shin Soe IV -do. 453 2a45 ie Reo aeoel ene eda eee ee) ae see el Le eI NS ere eit I| July 28 8144; 1655) 5ig| 435 -----+-- Lig Baia | 112 Sifa| <(2 oe mah II |....do... 9035 455 538 Dgg)+--++--- 24555) 336 1x Oxp)--+----- um on 8 ae 10855 1a ‘ | 45 se deafate 3785| 135 138 Dil enistoreee Rete lO Rer BO Pra BU) 235) ee ele ee eee ee ee ee ee ee ce ee ele eee \ Pave 8) ay a a Sl II |.-..do-.. 3135 2035, WSa5 1035, 30} —2a5 on6 235 ony 20 HT |-...d0...) 3645 175) 134s) 58 aos isd cs i 8 Cee) (Chee BO 30 BO BO BO) --e eee eel ee ee ee ee ee ee we eee ee ele eee eee SUMMARY REMARES CONCERNING THE EXPERIMENTS WITH CULTURAL METHODS. In the case of field experiments involving questions of the character of those presented above, final conclusions may not be drawn as the result of one or even several years’ tests. Variations in seasons and other conditions often produce results one year not verifiable the next; and what appears desirable for one character of soil may not be use- ful on another. The writérs would, therefore, be entirely unwar- ranted in making specific recommendations, especially as regards the use of certain fertilizer elements, on the data secured in the course of last year’s investigation. Certain general statements are, however, apparently warranted. At the Pittsburg, Wills Point, and other experimental farms the use of fertilizers resulted in a notably earlier and larger crop of cotton, as compared with the unfertilized check plats. On soils deficient in one or more of the three principal elements of plant food, namely, phosphoric acid, nitrogen, and potash, the appli- cation of the needed element or elements results in a more rapid and 212 24 larger growth of the plant and a consequent earlier and greater pro- duction of squares. It would appear that herein lies the principal value of fertilizers, as related to the production of an early crop. On the Pittsburg farm, attention is called to the larger and earlier yields obtained from the use of a fertilizer containing 10 per cent of phosphoric acid and 2 per cent of potash, and from the use of 14 per cent acid phosphate alone, as compared with a complete fertilizer analyzing, phosphoric acid 8 per cent, nitrogen 2 per cent, and potash 2 per cent. On the Wills Point farm the largest yield was obtained from the use of 14 per cent acid phosphate. Plats I, II, and IV, how- ever, show approximately the same total yield. The comparative earliness may be indicated from the following weights of seed cotton picked by August 26: Plat I, 2,325 pounds; Plat II, 2,029 pounds; Plat IV, 2,554 pounds. This gives again a slight balance in favor of an acid phosphate and potash fertilizer as to earliness of crop. It may: also be mentioned here that in the fertilizer experiments in 1904, on the plantation of Capt. B. D. Wilson, Hetty, Tex., on rich ‘‘ bottom” soil, the use of 400 pounds per acre of a phosphoric acid and potash mixture gave a considerably larger early and total yield of cotton than did the use of 300 and 450 pounds per acre, respectively, of phosphoric acid. The first picking from phosphoric acid and potash mixture plats, September 3, was 499 pounds seed cotton per acre. From the plat treated with 300 pounds acid phosphate, 3543 pounds of seed cot- ton per acre were secured; and from the plat receiving 450 pounds of acid phosphate the yield was 355? pounds of seed cotton per acre. The total yield of seed cotton per acre from the respective plats was 1,3873 pounds, 1,153 pounds, and 1,2803 pounds. It is, however, only intended to point out the usefulness, in general, of employing fertilizers in a system of cotton culture designed to pro- duce a crop ahead of bollworm injury. The exact character of the fertilizer and the quantity per acre to be used are matters of further experimentation. The previously tabulated data in regard to fertil- izers should furnish planters with a basis for experimentation by which they will finally arrive at conclusions true for their respective soils. Of equal importance in the production of early cotton is the use of varieties with an inherent tendency to begin fruiting early in the growth of the plant, or low on the plant, and on which the joints are short. Observant planters need not be told of the great difference in ‘fruiting habit of different varieties of cotton. The long-limbed sorts are necessarily later in setting squares, and they are also less prolific than those with shorter joints. The desirable qualities, as early fruit- ing, good staple, etc., may be perpetuated and improved by seed selec- tion. Seasonal conditions, such as a shorter growing season, have led, in the northern part of the cotton belt, to the use of early-fruiting, prolific varieties in those sections. Seed of such varieties, especially the King, 212 pe 25 has recently been extensively planted in Texas on account of these characteristics, in both the bollworm:and boll weevil infested regions. The importance of the use of selected early-fruiting varieties, as com- pared with the native ‘‘run-down” gin seed, was well illustrated in the investigations during 1903. On the plantation of Capt. B. D. Wil- son, at Hetty, Tex., under conditions of severe bollworm injury, early planted King seed produced an average of 1,348 pounds per acre of seed cotton, as against 187 pounds per acre of early-planted but late- maturing gin seed. The advantage of early planting is emphasized by results secured on various farms. On the Wilson farm in 1903 early-planted King with thorough cultivation gave 1,348 pounds seed cotton per acre, as compared with 360 pounds per acre from late-planted King also with thorough cultivation. Early and thorough cultivation is another important factor in the production of early cotton. Plants should be chopped out as early as practicable to admit of free branching and consequent square pro- duction. The fertility of the soil, either native or introduced by means of fertilizers, may be used by plants only in solution. Conse- quently, for the conservation of moisture and other reasons, timely and frequent cultivations are of the utmost importance. TRAP CROPS. Attention has been elsewhere called to the decided preference of bollworms for corn as compared with other plants upon which it is known to feed. This preference permits of the use of corn in a way calculated to protect cotton from injury. The corn should be planted in belts through the cotton field at a time that will result in‘its being in tassel and silk about the first of August. By this time moths are developing from larve matured in the roasting ears of neighboring corn which has now begun to ripen and is no longer attractive to the moths for egg-laying purposes. In the natural course of events, the moths migrate to cotton fields, where they deposit the bulk of their eggs. Finding these belts of corn in tassel and silk, however, they deposit on them the greater part of their eges, and correspondingly neglect the cotton plants. The September generation of lary is sometimes a source of considerable injury, especially to very late cotton. Corn may easily be brought into silk so as to attract moths of this generation by planting only a por- tion of the belts through the cotton fields at the time of first planting and then completing the work two or three weeks later. The same results may be secured by planting patches of corn here and there over the plantation, following crops of oats, wheat, or Irish potatoes. Cowpeas are very attractive to bollworm moths, owing to their fond- ness for the nectar profusely secreted by this plant. Thus the corn 212 26 trap rows may be made more effective by planting rows of peas alter- nately with rows of corn. The peasshould come into full bloom at the time the corn is silking. This will necessitate planting the peas about the time the corn appears above the ground. The advantage gained by the use of trap crops can not be expressed in pounds of seed cotton, as it is impossible to arrange a test so that the area left for comparison will be subjected to the same conditions without having it adjacent and consequently equally subject to protection by the corn. Boll- worm moths fly freely, and are therefore attracted to fresh corn from a considerable distance, and the influence of the trap rows is thus quite general. During 1903 tests of corn trap crops for protecting cotton against the more destructive August generation of bollworms were made at Calvert and Wills Point, Tex. Early in August the number of eggs upon 8 typical plants in the trap rows at Wills Point was found to be, on an average, 495 per plant, 804 eggs being the maximum number found on a single plant. No account was taken of eggs deposited on plants previous to or succeeding this time. From these figures some idea may be gained of the vast number of eggs which are thus diverted from cotton. In 1904 tests of corn as a trap crop were made at Sulphur Springs, Quinlan, and Hetty, Tex., and at Shreveport, La. The same general plan was carried out in all of the above localities, protection from the August brood only being sought. Belts from 10 to 40 feet wide extending across the field were left unplanted at the time of planting cotton, and these were seeded to Mexican June corn by June 1 in rows from 5 to 6 feet apart. Ten days later cowpeas were planted between the rows of corn, thus leay- ing ample room for cultivation. The corn was planted in about the proportion of 10 rows to 40 rows of cotton, and the individual fields varied from 20 to 40 acres. The following table, computed from counts made of the number of eggs on 20 typical plants in trap rows on the farm of Mr. J. T. Har- grove, Sulphur Springs, Tex., will give an idea of the number of eggs kept from the cotton by a few acres of trap corn. The figures show the average number of eggs for each plant and the average number on the various portions of the plants: — Tasite VII.—Distribution and average number of bollworm eggs on corn. Number of eggs on— Date be eed bang 1 cae cul aie ele, we Condition of corn, - plant | Leaves. | Sheaths.| Tassels. Silks. ant. | Daly 28) a8 bak 2 os 33) Aweust 16... ....:-.- 5 .1 | Many plants not in silk. 21.9 | Corn in roasting ear; silks dry- ing. 27 During a year of greater bollworm abundance the number of eggs that would be deposited on corn would doubtless far exceed the num- bers here given. The number of eggs occurring on an acre of trap corn at one time, as based on the above figures, is surprisingly great. Taking the average number of eggs per plant on July 28; as given in the table, the protection afforded by the plants on a single acre may be calculated in a theoretical way. Assuming the corn rows to be 6 feet apart and the plants 13 feet apart in the row, there would be on an acre 4,840 plants. On the average of 338.4 eggs per plant, as found above, there would be 1,637,856 eggs distributed over the acre of corn. By a series of observations it has been determined that a single boll- worm feeding freely on cotton will destroy on an average 8 squares, 1 flower, and 13 bolls during the course of its growth. Assuming that all of the fruit destroyed would have eventually matured, there would be a total destruction of 17,470,464 bolls. Onan average of 70 bolls to the pound of seed cotton, this would mean a destruction of 249,578 pounds of cotton in the seed, or at the rate of 1,500 pounds seed cotton to the bale, 166 bales. It must be remembered, however, that in the above calculations it was assumed that from every egg a mature larva would develop. This would be far from the case in reality. In fact it has been observed that on an average but one larva reaches maturity from about 50 eggs deposited on corn. It was further assumed that all of the squares and flowers injured would have otherwise reached maturity, which in fact would not be the case, as many squares and young bolls are shed by the plants on account of unfavorable weather or other con- ditions. However, after making due allowance for all of these condi- tions, the benefits to be derived froma proper use of corn asa trap crop are seen to be very great. It might appear at first sight that the practice of furnishing the bollworm with an abundance of its preferred food would simply result in its greater increase and consequent destructiveness. This, however, does not result, for when the eggs are concentrated on the corn plants, as on the silks, they are very largely destroyed by a certain parasite and by predaceous enemies, and the larve hatching from these eggs are largely killed by the cannibalistic habits of the bollworms themselves. Out of some 15 to 30 young larve which may usually be found ina recently silked ear of corn, but one or two bollworms will eventually reach maturity. Numerous instances have come under the observation of the writers where planters, in attempting to make use of trap crops, have made the mistake of planting the corn at the usual time in the spring. The result has been, that the cotton has suffered greater injury than would otherwise have occurred. The success of the trap crop idea as here 212 28 considered depends entirely on having the corn in tassel and silk on or about the first of August, and it must be planted considerably later than the normal time of planting corn in the spring. June corn planted the last of May or first of June, with good cultivation, will be silking and tasseling freely by August 1. The greatest benefit will come from the use of corn as a trap crop in its general adoption by the planters of a neighborhood. In the case of large plantations it is quite possible to adopt a system of grow- ing late corn, after oats, wheat, or other early-maturing crops, which will attract the bollworms from the plantation generally. An instance of this practice may be cited on the plantation of Mr. F. L. Maxwell, of Mound, La. It has been the practice of this gentleman to grow small areas of late corn after oats here and there over the plantation to the almost complete protection of his large cotton crop. USE OF ARSENICAL POISONS. The opinion prevails more or less generally among cotton planters that the bollworm may not be successfully poisoned, by reason of the fact that it bores to the interior of squares and bolls, and does not feed on the exterior parts of the plant to any extent. Such a belief is true only of the later stages of the larva. Theaverage planter seldom has his attention attracted by so small a creature as a newly hatched boll- worm, and it thus results that the habits of the insect during its early larval existence are practically unknown to him. This unobserved period in the development of the larva is the only time when poisons may be expected to exert any considerable influence in boilworm control. From extended studies of the egg-laying habits of the moth and the actions of the newly-hatched larvee there is every reason to believe, on theoretical grounds, that, by the application of poison to cotton at about the time the eggs of the large August generation begin to hatch, the injury from this insect may be greatly reduced. A series of observations made during the summer of 1903 on the distribution of eggs on cotton plants, as determined by watching the moths while ovipositing, showed that 73 per cent of the eggs were so placed that the resulting larvee would be readily susceptible to poison. By care- fully examining several plants, 65 per cent of the eggs were found to be on other parts than the squares, flowers, and bolls. During 1904 similar records were made by watching the moths ovipositing in cot- ton fields. The combined record of 25 moths is given below: 212 29 Distribution of bollworm eggs upon cotton plants. Eggs eaves: Wiper sanigces 4) 25 coe e cee cone eae. si sat 191 Menccot lower SUTIACE Ss. 20 coos lek. costae cee ee emacs ceceueus 194 RNGPRIRER RSENS Se SoS het oe ee Ag. oe ada meomoeocs Hoke 326 TEN PD east Se ee ee EE Se ee tho ee 110 PESO ata epee tied cee ate eyes ney ee Ne RS 120 MM EMRDUNISCRRIING yee AS ett S chras icnaia 5 ENS i met ee en 46 SUR SITUS! eh ees etek a sph pe rapes GARE Sn eed Ale Bs 3 a Mia ct ei 64 LETT (2c ig A ae Saeed Ae eS Ss 29 WGA persis f eamnat he ess Shae aio. AG Eda Soe ae eee 20 (Qoneeerts) Vota CARON TONO NE ae Hee ee cle eee A ee oe aes Ore ee 21 IDise yal Whee U. S. DEPARTMENT OF AGRICULTUBE. - FARMERS’ BULLETIN No. 216. THE CONTROL OF THE BOLL W EEVIL, INCLUDING RESULTS OF RECENT INVESTIGATIONS. We De HUNGER, Special Agent in Charge of Cotton Boll Weevil Investigations, Bureau of Entomology. fe is (ex hy / WASHINGTON: GOVERNMENT PRINTING OFFICE. 1905. LETTER OF TRANSMITTAL. U..S.. DEPARTMENT. OF AGRICULTURE, Bureau or ENTOMOLOGY, Washington, D. C., February 3, 1905. Srr: I transmit herewith a manuseript-entitled ‘‘ The Control of the Boll Weevil, Including Results of Recent Ivestigations,’’ prepared by Mr. W. D. Hunter, special agent of this Bureau in charge of experimental work with the cotton boll weevil. This paper will replace Farmers’ Bulletin No. 189. It contains the previous recom- mendations of the Bureau of Entomology regarding the means of mitigating the damage by this very serious pest, with such minor modifications as have been made necessary by the work of the past season. In addition, various topics, such as the territory infested, the present status of State quarantines against the boll weevil. and other matters, are considered. I recommend that it be issued.as:a Farmers’ Bulletin. Respecttully, L. O. Howarp, Hon. James WILson, Chief of Bureau. Secretary of Agriculture. CONTENTS: 1 Page. MecCOMIMeNGHONS. 2222... 2s Silo lees eee oe nee Soe eee ees 3 iirodnetorye fi... cas ok es cells SOR RAE SS Do pe ee eee aie 6 DAsormpiion. of the boll weevil... «i053 -a3 gees «aes. ee eee wen al 8 SES PiEnORy HIGCUEE toe ot a oat ea = ite ale mine ain at a ee ies aw a re ee 10 Danieeeaused by the boll weevil>..c2.c a2 oDesk ese eek ase ee ee “12 PAS Vane by: GES bis Sees oe a sieit S ey eer hain ik, Can eee ene och ec ee 15 Conclusions regarding the use-6f fertilizers ..-.....-..-.2.---------- 2 eee eee 18 Relation between .seppa cotton,and weevil damage.........--..--.-.-------- 20 Experiment mradererred plantar ee ie ae alee ow ie al ln me al 20 Controlling the boll weevil in cotton seed and at ginneries .........--------- 22 Supposed immunity of Mexican cottons 22-2) 3_- 22250 25 ee See eee ee oe 22 Futile methods suggested for control, :..-2:-. 22223. fe os ee eee oe 23 Quarantines against the boll weevil... 22... 2- J2.- =: o+ += ese oe eee = 25 Suggestions for a uniform State boll-weevil law. ......------------------ 26 Present quarantines of the several:States.......-.-----------.---------- 28 Alaibamia oO. 2/ 22.5 Sees «hacer ee sie er A oe a ore eee 28 Georg. 222. .--545n 2G cenane Weae sodwie tigate Smet f= “a 4 d pee ae S ; g = fe = Fic. 3.—Cotton square flared, showing egg puncture of boll weevil—natural size (original). 216 9 Every intelligent planter in the weevil-infested area should be able to determine the presence of the pest by its appearance and the evi- dences of its work; but planters who have never seen it may often be in doubt as to whether some insect found damaging the crop is the boll weevil, or whether flaring and falling of the squares is caused by some other unseen insect pest or by climatic conditions. For the benefit of planters outside of the present weevil territory, in regions where the ‘pest is more or less likely to be found at any time, the following description of the insect and its work is given. It is believed that this description will enable any planter to determine whether the pest is at ae eal \, ; ALPE Fic, 4.—Cotton square cut open, showing boll weevil larva in position—natural size (original). work in his field, so that he may take the necessary steps to fight it at the earliest moment. The adult weevil averages about one-fourth of an inch in length, ranging from one-eighth to one-third inch, with the breadth about one- third of the length. This measurement includes the snout, which is about one-half of the length of the body. The color is a grayish or a yellowish brown. The general form will be understood from fig. 1. The insect exists in four stages—ege, larva, pupa (fig. 2), and adult. All the stages, except the adult, occur only within the cotton square or boll. The egg is deposited by the female weevil in a cavity formed by eating into the fruit of the plant (fig. 8). It hatches, under normal 216 10 conditions, in about 3 days, and the grub immediately begins to feed. In from 7 to 12 days the larva or grub passes into its pupal or trans- formation stage, corresponding to the cocoon stage of the silkworm. This stage lasts from 3 to 5 days. Then the adult weevil issues, and in about 5 days begins the production of another generation. Climatic conditions cause considerable variation in the duration of these stages, but on an average it requires from 2 to 3 weeks for the weevil to develop from the egg to the adult. The plainest indication of the presence of the weevil in a cotton field is the flaring (fig. 3) and falling of the squares or forms, which takes place generally between 5 and 10 days after the egg is deposited. However, as all planters are aware, heavy rains after drought, as well as other climatic conditions, have the effect of causing the squares to fall. If the planter should observe an unusual shedding of the fruit, he may easily determine the cause by gathering a few of the fallen squares. If, upon cutting open these squares, he finds a small, whitish, curved grub (fig. 4), there - can be little doubt that the cause of the trouble is the boll weevil. Specimens should then be securely packed and sent to an entomologist for final determination. TERRITORY AFFECTED. During the season of 1904 the normal increase in infested territory occurred. About 15,000 square miles, represénting approximately an area devoted to the cultivation of cotton of 900,000 acres, the normal . production from which would be in the neighborhood of 350,000 bales, became invaded for the first time. This increases the infested area in the United States at present to about 32 per cent of the total cotton acreage. One of the most interesting features of the situation during the past season has been the fact that the infested territory has been extended eastward much more rapidly than northward. Careful examinations of the portions of Indian Territory which the boll weevil is likely to reach first have failed to reveal any infestation. In fact, on the north. the limitation of the infested territory remains practically the same as last year. This applies, however, only to the total infested area in which even isolated colonies of the pest have been found to exist. There has been a gradual northward advance of the limits of the region of what may be termed ‘‘ gross infestation;” that is, where the weevils are to be found in considerable numbers in all cotton fields. This advance has extended from about the latitude of the northern portion of Ellis County to the latitude of the southern portions of Denton and Collin counties, a distance of about 36 miles. The situation mentioned in the preceding paragraph leads to specu- lation as to whether the pest has not reached a northern limit beyond 216 11 which its spread will be prevented-or at least checked by climatic con- ditions. During the past year it has been found that there is:at least one full generation less at Terrell; Tex., than at Victoria, Tex., 275 miles south-of that place. With the very rapid multiplication of the pest, this means greatly lessened actual damage. The itime when the maximum number of weevils per-acre 1s produced is made considerably Jater, with a consequent manifest advantage to the crop. The lessened number of generations is due to three principal factors: (1) Later emergence from hibernating quarters; (2) greater time required for the development of the several stages; and (8) the earlier date of the first killing frost. These considerations would, theoretically at least, cause the weevil problem to become.a much less serious one in extreme northern Texas than it has been in regions that have heretofore been infested, and the observations of the last.season bear out ‘this sapposi- ition. However, it is to be-expected ‘that there will be some adaptation on the part of the weevil to the climatic conditions in newly invaded regions, and this introduces considerable uncertainty in any prediction regarding future damage. The present indications are that the great- est damage by the pest will always be in the region south of the lati- tude of Dallas, Tex. To the east there has been.a general extension of the infested terri- tory of about 50 miles. The pest has been found east of the Red River at three points in Louisiana, namely, Lockwood, Grand Ecore, and Shreveport. In that State the greater portion of six parishes is known to be generally infested, while in three others the weevils are known to oecur in certain localities. Special opportunities for studying this spread were given by the cooperation which the Bureau.of Entomology carried on with the Louisiana crop pest commission. It was found that there was an advance early in the fall due to the fact that the weevils were carried from place to place in seed for planting purposes. This was followed by considerable increase in territory due to the convey- ing of the seed cotton to the gins, and, most important, there was an advance due to:an actual migration in August and September, which in many cases reached far beyond the limits of the territory covered by the first two means which have been mentioned. At frequent intervals during the past season (1904) accounts of the occurrence of the boll weevil at various points far beyond the limits of the infested territory indicated upon the accompanying map (fig. 5) have appeared in the newspapers. It seems likely that the pest may at any time be carried to points far outside of the present infested territory through the ordinary shipments of cotton products. There is ‘also some possibility that persons who have received live speci- mens from Texas for experimentation with supposed remedies may inadvertently introduce them into uninfested fields. In consequence of these probabilities, the Bureau of Entomology has devoted special 216 419 attention to the reported occurrence of the weevil outside of the region indicated upon the accompanying map. A number of reports origi- nating in Louisiana, Arkansas, and Indian Territory have been inves- tigated by entomologists connected with the Bureau. Through cooperation with State and station entomologists the Bureau has obtained specific information about reports originating in Georgia, AS ae yA gen | red WI) COTTON GROWING AREA SY WEEVIL INFESTED AREA Fic. 5.—Map of territory infested by boll weeyil. South Carolina, and elsewhere. All such reports investigated have been found to rest upon a mistaken identification of some of the numerous insects more or less resembling the boll weevil which have been found in cotton fields. DAMAGE CAUSED BY THE BOLL WEEVIL. The following table, reproduced from Farmers’ Bulletin No. 189, shows the great damage caused by the boll weevil: Comparative estimate of amount of damage by cotton boll weevil. Typical counties in which weevil was not present | Typical counties in which weevil was not present in 1899, but was present in 1902. in either 1899 or 1902. Product in com- | Productin com- mercial bales. mercial bales. County. : County. 7 1899, 1902. 1899. | 1902. Calawellisce® cnitics decides accnccs 47, 473 235133 | Montapues!. scoee-eenenasess- 15, 064 16, 981 COlOVaDO=- Seeane seen Samos eee 30, 923 11, 493 |: Cooke~ 02222. pee eee se 11, 905 11,012 RU CUCL fo teres roe s caee 73, 238 31,200; |; Grayson. 2225 eee seeeeaue. ee 40, 871 54, 087 GORZAIER Paes scm cete ccicne ee 44,131 2} Sol.) Pannin Hace se see oeecac eek 59, 802 70,540 — GnntGS 2.6 oa se ee 26, 541 125185"| Lamay woes tee ee teen a esse 49,193 59, 269 BW AC Rites aac icmechinnca aa neemeere 42, 484 22,906. > Wiser? so-2 op eememee een cs aero 17, 556 18, 869 Montromerys. 22. cfkee see oe 10, 272 3; 660-4 Denton jhe tee ee anc ac ae 20, 381 24, 541 Da CLLR ee Bec cae 8, 826 3,044: | Collin — = eee eeeceine xe sees 49, 077 47, 344 WUT ape Sete eRe SIS eet Ft aoe 60, 078 98-282) EIN 2 Saree nee . Cee 50, 317 49,713 DOVATTSUE TOM coe ioe Abe ehcp 27, 383 12: 870% WW eligicn 1c, aeeeee comes ai cee 24, 705 26, 256 Motel .< 6 o se sstenas oosaers 371,349 | 174,174 | Ota a Soe Sone eee 338, 871 378, 612 Decrease .s....2-22- pericentidl) 2heisecas 53° | dlerease se x.....25 2-2 per cents. Jas. .22s 11 13 The first section of. the above table shows a comparison of the pro- duction in ten counties in Texas in 1899, when the weevil had scarcely reached them, and in 1902, when it had multiplied to such an extent as to be found in great numbers in practically all cotton fields. These wo years were selected for comparison for the reason that they were practically identical in amount and distribution of rainfall and in other essential crop conditions. The second part of the table gives < comparison of the production during the same years in ten other lead- ing counties situated so far north that the weevil had not affected them in either of the two years used for comparison. It will be noticed that while in the counties of the first series there had been a decrease in production of 53 per cent, in the counties of the second series there had been an increase of 11 per cent. There seems to be no reason why the cotton production of the counties of the first series would not have increased at about the same rate as was the case in those of the second series had it not been for the damage caused by the weevil. This makes it fair, it is believed, to conclude that the approximate damage caused by the insect was the sum of the decrease in one case and the increase in the other, or about 64 per cant. There are two sources of possible error in these figures. One is in the likelihood of a change in acreage between 1899 and 1902 that may not have affected the two regions alike, and the other is in the proba- bility that the two seasons were not exactly similar. In relation to the first point it must be stated that increases in acreage are generally the result of conditions of the markets that would affect the whole State alike, and that if there were any increase in these years it would probably have been very much alike in either case. As to the possi- bility of an appreciable difference in the seasons, it must be stated that the two regions are comparatively close together, and that a care- ful examination of the records shows that they were remarkably alike in all important respects. Nevertheless, it is the tendency of planters, as soon as the weevil becomes a serious menace, to devote more of their land to other crops. Accurate figures on this point are not obtainable, but on the whole an allowance of a reduction of this kind that would account for 10 per cent decrease in production would be ample. It therefore seems to the writer that a figure in the neighborhood of 50 per cent represents a very fair approximate estimate of the loss. Upon the foregoing basis, assuming that there is a loss of about 50 per cent in newly invaded regions, but with an offset due to improved methods in older regions, it seems very conservative to state that, during the season of 1904, the weevil caused a reduction of at least 450,000 bales, representirg a value, including that of the seed, of about $22,000,000. 216 14 There are many interesting features connected with .the relation between the damage of the weevil and the present very large cotton crop (estimated by the Bureau of Statistics of this Department, Decem- ber 3, 1904, as 12,162,000 bates). The question. has been:raised as .to why the:weevil.is a great menace in view of ‘this large. production. and the fact that: the pest. has now invaded at least 32 per. cent of the. cot- ton acreage in this country. The following appear to. be the principal reasons for the present large. production: (1) The high price of cotton just:prior to the time.of planting .the crop of 1904 undoubtedly had the effect.of increasing the acreage considerably. (2) The boll weevil -has not yet reached numbers :in all its range sufficient to appreciably reduce the crop. The map on.page 12 outlines the total-area in which any weevils are known to occur. In perhaps 10 per.cent of the «territory thus considered infested only isolated colonies occur, and the general production has not yet been curtailed. In some. of the northern counties of Texas the production could -not have been: reduced by the weevil, although the statistics-show consid- erable variation between the crops produced for .the past several years on account. of changes in acreage and the ravages of other insects, like the bollworm. : (3) Throughout the portion of Texas-where the bulk of the crop is produced—that is, north of about the latitude of Bremond—various conditions. combined.to. cause an-unusually small number of weevils. to hibernate successfully during the winter of 1903-4. The principal factor in this situation was the very early date of the first killing frost, which was about thirty days prior to the average date for the past. fif- teen years. ‘This early frost destroyed a great number of immature weevils in the squares and bolls.which would otherwise have passed through the winter to damage the crop in spring. (4) An important factor which has contributed to the production of a large crop in the region just. mentioned has been a lessened degree of damage by the bollworm. It is.estimated by Mr. A. -L..Quaintance, who has. been in charge of a‘special investigation of the bollworm, that the pest.could not have caused more than half the damage in 1904 that was caused by it in 1903. (5) The growing season was unusually favorable. The average condition of the growing crop in Texas, from May to, September, inclusive, as published by the Bureau .of ‘Statistics of this Depart- ment, was 82 in 1904, as'against 72.5.in 1903. The average condition for 1904 was, in fact, much higher than in:even the season. of the largest crop ever produced, namely, 1900, when the average condition reported for the months mentioned was 77.6. 216 15 (6) The -season of 1904 was exceedingly favorable during the time of picking ‘the crop, resulting in.an unusually small loss.of lint from rains. (7) The large amount: of »work done bythe Department. of Agricul- ture and commercial bodies which imported many carloads of improved seed doubtless contributed to:the large crop produced. A general idea of ‘the effect.of the ravages of the ‘boll.weeviliin reducing the crop:in Texasimay be obtained from the following table: Comparison of cotton acreage and production in Texas and Louisiana, im-equivalents of . 500-pound bales. Texas. Louisiana. Year. - . - if Acreage. Crop. Acreage. Crop. Acres. Bales. Acres. | ‘Bales. (| CHE) Ake He SA Boe SSSR ce are Terenas 6, 642, 309 2,609,018 | 1,179,156 | ~ 700/352 Dee Pe in Sacem sets SSE o o> Splag delcds mata wanes 7,041,000. | 3,438,386 | *1, 285, 000 705, 767 PRC Haren ne oe dismcidia rast Oe oc Succ a smancaceseucesnelesia 7,745,100 | 2,502,166 | 1,400, 650 840,476 Ee me eee aon 6 a atc chslnuag sie oe oie gansta ae aise Wlepeeipelsainens -8,006,546 | 2,498,013 | 1; 662,567 882; 073 STUB? 2 2 eile ape al a apt elect east aie eer pane Seu 9 8}129,:300 | 2,471,081 | 1;709, 200 824, 965 upc Seah oiaarigie s Ske aciaie SO Ea aL h Uda Ba maniee sce pene 8, 704,000. | 38,080, 433. | .1,940;, 000 893,193 Tt will be seen that while ‘the acreage in Texas and Louisiana has been increasing at about the same proportion, the crop in Texas has decreased annually for the past six years (with ‘two exceptions—1900 and the presentyear), while the crop in Louisiana has increased annu- ally (with one inconsiderable exception—in 1903). ‘That'the boll weevil is the cause that has prevented Texas from keeping pace with Louis- ‘jana will be admitted by all. The exceptional years, 1900 and 1904, in which the production in Texas did not decrease, were undoubtedly those in which the conditions for the cotton plant were unusually favorable. Moreover, it is to be noted that in the first of these two years'the pest had not reached far into the most productive counties. A VARIETY TEST. In order to test.the suitability of a number of varieties of cotton for planting in weevil-infested regions, during 1904 the Bureau of Ento- mology planted the seed of 20 of the more or less well-known varieties at Calvert, Tex. Each variety was represented by a plat 5 acres in extent. The-soil was uniform throughout the.acreage covered by this experiment. The test was a severe one on account of unusually unfavorable local.conditions. The crop was made several weeks late by successive frosts early in the season. By a comparison with :the results of the variety test conducted during the-season.of 1908, which 216 16 was noted in Farmers’ Bulletin 189 of this Department, it will be seen that the general advantage of the early maturing varieties over the late maturing ones is again demonstrated. During that season the Herndon variety turned out to be the most prolific. This variety was not tested during the season of 1904, for the reason that it was impos- sible to procure seed. It was a local variety known in only one county in Mississippi, and seems to have died out on account of the general desire of planters for varieties which have large bolls. In reality the superiority of the early maturing varieties would be more in evidence than the following grouping would indicate. In arranging the planting of varieties in the field the earlier ones were placed nearest the timber. It was designed to have the varieties graded from the vicinity of the timber erage to their relative earliness. Consequently the King variety was nearest the timber, and the Russell most removed. As is usual in such cases , the weee appeared in the cotton near the timber first. For two nae before any of the pests had appeared in the middle of the field they were causing considerable damage in the plats nearest the timber. It is not possible to give varieties of cotton a complete test during a single season. The only correct basis for an estimation of the value of different varieties in weevil-infested regions is a repetition’ of experiments during several seasons. As has repeatedly been found to be the case in the tests of varieties of cotton which have been con- ducted by southern experiment stations, the changing climatic condi- tions alter the relative standing of the varieties very materially. In some cases a variety found during one season to be at the head of the list in production may, during the following season, fall far below. Work that has beea conducted elsewhere in Texas indicates some prob- able modifications of general conclusions that might be drawn from this test. For instance, the Rowden variety would probably rank con- siderably higher than was the case in these experiments. Neverthe- less, it is believed that the test conducted by the Bureau of Entomology in Robertson County will furnish the basis for a general idea of the value of some of the principal known varieties. The lint from the varieties was given commercial grading as speci- fied in the accompanying table, by a special committee of members of the Galveston cotton TEN appointed at the suggestion of the writer by the president of the a tinte The name ‘‘ Georgia Truitt” applies to the seed of the well-known Truitt variety from Georgia. The name ‘‘ Texas Truitt” is used to differentiate the cotton grown from Truitt seed which had been planted in Texas for one year. The same distinction applies to the names ‘* King” and ‘** Texas King.” 216 =o Te 17 Comparison of cotton varieties. Yield per | mits | Variety. fae a FP peas Bank by Class. | Staple. = cotton. of lint. yield. Pounds. | Permitory -.-..- kat 885. 4 28.17 2 | Barely low middling --......-....- Weak. Georgia Truitt..... 719.0 27.76 Si Strict.200d/ ordinary 22.2) = esseee Fair. RUNNIC Caen cds atac es 670. 4 32.07 6: | Bow mid @hing= ss... 5... c2s-aeemeee Do. PIGKAONM = s.. sie ce 436, 2 28. 91 14 hor: middling to strict low mid- | Poor. 3 ing. | MOXASICING ines = 599. 2 29. 25 7)| Strict low: middling: 55.22 -nencn-see Fair. - EVENS) ~ 25.0% a's ARS Sees acane se 12°| Strict good ordinary. -.--2..2t5---- | Do. WanmeNose. i: 2... DTU |G eee pe eee (ee GOV ei a= seinkine eee ue ~ ae Beeeacios } Do Texas Truitt..--..- 511.4 27.75 Wl Eee Olga ee saeae rs cane eee erate a Poor. Lg een ee 863. 4 31-32. 53 3) | Strict low, middling 22.2. :-.222-2. =. Do NUL OL. .2s.5ee%- 427.2 33. 28 TGs -. OSS Se acecckwe ec eee a+ sae oe ane Fair Seles he. Seis SOL Oulecaes abe - ade an Good ordinary. o-oo. 2 -2ssaeaeee Poor. PROOMM sree Sa <5 944.8 30-34. 43 Lleete GO eae mis ewlecresaiaece lobes taee Very poor. IROWMEU) os. 225.2 k VT eee ee lee : DO howe MIG GINS shea) aes teeees Good. PSCTUN es sn sie e's eee BOSTON we asec sree. 19 | Strict good ordinary. ...-.-2.-....: Very poor. Li eo a eee 566. 6 29. 95 Oil how middling cee. sss oe te 8. Good. Mexas Kane .. co... 599, 2 27.74 7 |-Strict £000. OFGIMALY...<..-2 22-02-52 Fair. MMBRCOUG ©. 5-2 nccen- 534. 4 33. 52 10;| Strict low middling,............... Do. ORD eae ee 398.0 33. 23 46 "GOOG Ord Inarye ce -octee = <2 heen coe Poor. Hawkins ...:-.--:- 845. 0 32. 33 4 | Good ordinary to strict good ordi- Do. | nary. Culpepper ....-..... DOO NOM vais s wares = 21 | Strict good ordinary.............-- Fair. PETQLQUIV oo nso oo 0's BOMe ule. ae aeee ess 183} Good ordinary: <2)... ..5~ sec ee = Poor. PSUEEMC St Soya clove oc atee AOS Gull nas Sees ae Agee se GO oases coe Mace eee ieee Do. PLCULY =~ 12-25 20'<~ 55 476.0 31. 82 Tot | PO We MIG eee oes ck wooo Fair. Welborm2 725.52. .-< oS BN ee aera] 90.| Strict good ordinary.s........2. 2... Do. Arranged according to production, these varieties may be grouped in the following manner: First group, yielding from 700 to 1,000 pounds of seed cotton per acre: Tool’s, Territory, King, Hawkins, Georgia Truitt. Second group, yielding from 500 to 700 pounds of seed cotton per acre: Shine, Texas King, Texas Truitt, Parker, Mascott. Third group, yielding from 400 to 500 pounds of seed cotton per acre: Van Nose, Meyers, Hetty, Dickson, Native. Fourth group, yielding from 200 to 400 pounds of seed cotton per acre: Russell, Eudaly, Berry, Welborn, Culpepper, Rowden. Arranged according to class, the above-mentioned varieties may be ranked in the following manner: Fair: Texas King, King, Native (No. 10), Mascott. Middling Fair: Dickson. ; Good Middling: Shine, Rowden, Parker, Hetty. Middling: Georgia Truitt, Texas Truitt, Meyers, Van Nose, Berry, Texas King, Culpepper, Welborn. Low Middling: Territory. Good Ordinary: Hawkins. Ordinary: Russell, Tool’s, Otto, Eudaly, Native (No. 28). The two ‘‘ natives” represented two different lots of seed. Arranged according to staple, the varieties stand as follows: Good: Rowden, Parker. Fair: Georgia Truitt, Shine, Texas King, Meyers, Van Nose, Native, Mascott, Culpepper, Hetty, Welborn. Weak: Territory. 216 20533—No. 216—05——2 18 Poor: Dickson, Texas Truitt, King, Russell, Otto, Hawkins, Eudaly, Native. Very Poor: Tool’s, oe Arranged Bg bts to the average rank by class and staple, the varieties could be grouped in the following manner: First Group: Texas King, Native (No. 10), Mascott. Second Group: Rowden, Parker. Third Group: Shine, King, Hetty. Fourth Group: ae gia Tr uitt, Dickson, Meyers, Van Nose, Texas King, Culpepper, Welborn. Fifth Group: Texas Truitt. Sixth Group: Territory. Seventh Group: Berry. Eighth Group: Hawkins. Ninth Group: Russell, Otto, Eudaly, Native. Tenth Group: Tool’s. CONCLUSIONS REGARDING THE USE OF FERTILIZERS. The Bureau of Entomology has not conducted any special tests of fertilizers. However, in the prosecution of a great number of the general experiments, it has been necessary to make use of commer- cial fertilizers. In view of the lack of exact knowledge regarding the proper use of fertilizers in Texas, due to conditions which are in many respects dissimilar to those in regions where experiments with fertilizers have been conducted, it is considered advisable to present some of the incidental results along this line. The uncertainty connected with field experiments during a single season is nowhere more marked than in the use of fertilizers. The benefits derived from the use of fertilizers depend upon soil and climatic conditions, as well as upon the preparation the ground is given. The climatie conditions may cause some fertilizers to be available during one season, while during another season no results might be evident from their use. During the season of 1904, the results of the use of fertilizers were confusing. However, some of the results that are doubtless of more or less general application are referred to in the following paragraphs. That these conclusions are approximately correct is shown by the fact that they agree in a gen- eral way with the results of the various State experiment stations which have conducted fertilizer experiments in the South. On sandy post-oak land in Robertson County, in one case the appli- cation of a fertilizer consisting of 200 pounds of cotton-seed meal and 216 19 100 pounds of acid phosphate per acre produced a yield of 900 pounds of seed cotton, which was 50 per cent more than the yield of the same variety of cotton in an unfertilized part of the same field. In another ease, on similar soil in Robertson County, 200 pounds of acid phos- phate (14 per cent available phosphoric acid) caused an increase of 163 pounds of seed cotton per acre. On river-bottom soil in Robert- son County an application of 140 pounds of cotton-seed meal with 140 pounds of acid phosphate per acre caused an increase in yield of 180 pounds of seed cotton per acre.. In this locality, as well as on alluvial soil in Wharton County, the application of 200 pounds per acre of acid phosphate having 14 per cent of available phosphoric acid did not increase the yield appreciably. The most striking results from the use of fertilizers were obtained in the case of the work conducted in Washington County on heavy, sandy river-bottom soil, which had been planted in cotton or corn for at least fifteen years. The application of 200 pounds of acid phosphate inereased the yield about 20 per cent. The application of 300 pounds of this fertilizer increased the yield in the neighborhood of 50 per cent, not only in the case of improved varieties, but also in the case of native cotton. The largest yields obtained anywhere during the season by the Bureau of Entomology were in this location. One field of native cotton, fertilized with 300 pounds of acid phosphate, yielded at. the rate of 1,712 pounds of seed cdtton per acre. Two other plats fertilized at the same rate yielded 1,632 and 1,437 pounds of seed cotton per acre, respectively. Some of the plats fertilized with the amount of acid phosphate that has been mentioned did not yield nearly as high; nevertheless the average on the fertilized plats reached in the neighborhood of 1,000 pounds of seed cotton per acre as against an average yield of 527 pounds of seed cotton per acre in the case of - unfertilized plats. Upon black prairie soil in Karnes County, 200 pounds of acid phos- phate per acre on the average, with several different varieties of cotton, increased the yield considerably. On 30 acres of early maturing ~ varieties and native cotton, the amount mentioned resulted in a net gain of $5.65 per acre. Heavier applications of acid phosphate, at 400 and 500 pounds per acre, did not result in a net gain greater than that mentioned in the application of 200 pounds. On the same planta- tion an application of 300 pounds of a complete fertilizer, analyzing 8 per cent phosphoric acid, 2 per cent nitrogen, and 2 per cent potash, caused an increase in the yield per acre of 253 pounds of seed cotton, resulting in a net gain per aere of $5.07.« A careful consideration of the subject of the fertilization of cotton in Texas, by Prof. R. L. Bennett, will be found in Bulletin No. 75, Texas Agricultural Experiment Station. 216 20 RELATION BETWEEN SEPPA COTTON AND WEEVIL DAMAGE. The winter of 1903-4 was unusually mild in Texas. The conse- quence was that the region in which volunteer cotton occurred extended much farther north than normally. Some volunteer cotton occurs in Texas every year, but its occurrence north of about the latitude of Victoria: is unusual. During the year 1903-4 much volunteer or seppa cotton was found as far north as Milam County. A line through the middle of Milam, Williamson, Travis, and Hays counties would indicate the northward limit of the territory in which seppa cotton occurred during the season. In many fields in Karnes, Wilson, and other counties practically every root of the preceding year over- wintered. It must be evident to any observer that this condition must conduce to the most successful hibernation of the weevils. They are provided with food practically throughout the winter, and in the spring there is an abundance of green sprouts long before the planted cotton has come up. The consequence is that there is a much smaller mortality rate during the winter in this region than elsewhere. The very great damage which was done in 1904, in the counties of south- west Texas last mentioned, was due to the occurrence of this seppa cotton. By the latter part of June it was found that in some locali- ties practically all the fruit on these plants had become infested. This resulted in at least one additional brood of weevils to prey upon the planted cotton. The Bureau of Entomology has repeatedly pointed out that the presence of volunteer cotton is the greatest menace to the crop that exists in southern Texas. The encouragement of such plants is undoubtedly the worst possible practice in weevil-infested regions. The disastrous experience of many counties in the southern portion of the State during the past season has abundantly demonstrated the force of the warnings that have been issued from time to time. The staple produced upon seppa plants is exceedingly short and weak, and is not desired by the trade. Before the advent of the weevil, the pale reason for encouraging such growth was to procure the first bale. Now, on account of the fact that the presence of such plants intensifies the seriousness of the weeyil problem, any attempt to produce cotton from the stalks of the preceding year should by all means be discour- ayed. The proper procedure would be to destroy all the plants in the field early in the fall, as suggested in the list of recommendations. EXPERIMENT fN DEFERRED PLANTING. In Texas some little attention has been attracted to the proposal of eradicating the boll weevil by deferring the time of planting until very 216 ee 21 late in the season. The idea has been that by following with such a practice after the early destruction of the plants in the fall the hiber- nating period of the weevils could be so lengthened that all would perish. From superficial considerations it would seem that late plant- ing instead of early planting would be the proper way to avoid damage by the pest. In order to determine this point definitely, the Bureau of Entomology conducted a special experiment at Victoria, Tex., during the season of 1904. Bul. 62, Ohio Agrl. Exp. Station (1895). ¢ Bul. 184, Cornell Univ. Agrl. Exp. Station (1900). d Bul. 19, Office State Ent. of N. Y., p. 20 (1903). 284 8 entire number being nearly 175 eggs per female. According to the same writer, about 45 per cent of the eggs of the individuals above men- tioned were deposited during the first two weeks, and 73 per cent of the entire number were deposited during the first month after emergence. Beetles are to be found on the vines during a considerable period, owing to their longevity and to an irregularity in emergence, though, as stated, oviposition is largely done during the three or four weeks fol- Fig. 1.—Grape root-worm (Fidia viticida): a, Aduit or beetle; b, eggs on cane, about natural size; c, eggs, enlarged; d, full-grown larva; e, pupa; f, f, g, roots of grape, showing injury by larve; h, grape leaf, showing characteristic chaim-like feeding marks made by beetles. a, c, d, e, Much enlarged; 6, g, about natural size; f, h, reduced. lowing emergence.. Upon being disturbed many of the beetles will lose their hold upon the vines and fall to the ground in their efforts to escape detection. Advantage may be taken of this fact, as explained later, to collect the insects from the vines by jarring. Egg.— Kees are deposited in patches usually from 25 to 40, some- times less, but rarely more, according to Slingerland, mostly under the 284 2 bark of last year’s wood, and may occur quite generally over the canes, some quite near to the upper wire of the trellis. As stated by Professor Webster“; 700 eggs were found on a single vine, and 225 eggs from a section of a cane but 16 inches long. The eggs are nearly cylindrical in shape, tapering at each end; whitish when first laid, but soon becoming ellowish in color. The eggs are about one-twenty-fifth of an inch in ength, and more or less concentrically arranged in patches. From 9 to 12 days are required for the eggs to hatch. See figure 1, at 6 and ¢, showing eggs on grape cane and more enlarged. Larva.—On hatching, the larve drop to the ground. At this time they are about one-seventeenth of an inch in length, and from their small size are readily able to find their way through the soil. Although the powers of locomotion and endurance of the young larve are con- siderable, to enable them to overcome difficulties in reaching their food, many doubtless fail to do so and perish. When established on the roots, however, the grubs feed freely and grow rapidly. By fall the majority of them will be full-grown or nearly so. Upon the approach of cold weather they descend into the earth several inches, a few as much as a foot below the surface, and here construct oval earthen cells in which they pass the winter. With the approach of warm weather the larve ascend to a point near the surface, the immature ones completing their rowth, and the pupal stage is entered mostly from about 2 to 3 inches ee the surface of the soil and within a radius of 14 to 2 feet from the base of the vine. The full-grown larva is about five-cighths of an inch long, the body whitish, resting in a curved position. The head is yel- lowish brown in color, with a transverse diameter somewhat less than that of the body. The spiracles or breathing pores along each side are well marked, varying from light to yellowish brown in color. As shown in figure 1, at d, the insect in this stage resembles in miniature one of the common white grubs, from which it may be distinguished by the dark food material in the abdomen of the latter. Pupa.—The full-grown larva prepares an earthen cell, within which it shortly changes to the pupa or “turtle” stage. In this condition the insect is soft and helpless, and the earthen cells are readily broken open and the pupe crushed or otherwise killed by stirring the soil. As stated, the majority of the larve pupate about 2 or 3 inches below the surface of the ground, and this makes possible their destruction in large numbers by timely cultivations, as will be explained under the discussion of remedies. Pupation is perhaps at its height just before the blossoms of the grape begin to open, but the vineyardist may determine the period with exactness by examining the earth around the base of infested vines to ascertain the proportion of pupze and larve present. Throughout the Chautauqua, Erie, and Ohio grape belts, during normal seasons, the insects will be in the pupal stage in maximum numbers during the first two or three weeks of June, varying somewhat, however, according to season and the char- acter of the soil, being earlier on sandy and later on clay soils. The ie is shown in figure 1 at e. Itis from one-fourth to one-third of an inch long, whitish in color, but with a pinkish coloration about the head, thorax, and caudal portion. On the head, body, and append- ages are spines, as shown in the figure. The pupal stage lasts about two weeks. a Bul. 62, Ohio Agrl. Exp. Station, p. 82 (1895). 27724—No. 284—07——2 10 Natural Enemies. No parasitic enemies of the beetles, pupz, or larve are recorded, but Professor Webster, in Ohio, has bred from the eggs two species of small hymenopterous wasps, namely, Fidiobia flavipes Ashm., and Brachy- sticha fidie Ashm., which he found to be doing most excellent el The former parasite was also bred from eggs by Slingerland in New York State in 1905. Eggs are also attacked by two or three species of small mites, which destroy them by extracting the contents. The common little brown ant, Lasius brunneus var. alienus, also has been observed to feed upon the eggs, and several predaceous insects were found by Dr. E. P. Felt in the course of his field work in New York occurring in the soil infested by root-worms, and he thought it prob- able that these preyed upon this species. The beetles are no doubt fed upon by insectivorous birds and barnyard fowls, which also are known to feed upon the pup exposed in cultivating. Treatment. The insect may be fought in three important ways, namely, by poisoning the adults with an arsenical spray, jarring them from the vines onto sheets, and destroying the pup in the soil by cultivation. Poisoning.—Shortly after emergence the beetles begin to feed upon the foliage, eating holes in the upper surface of the grape leaves, and hence may be readily poisoned. The use of poisons was recom- mended by Mr. Marlatt? in 1895, while Messrs. Slingerland and _ Johnson have shown by extensive practical experiments that the numbers of the pest may be greatly reduced in this way, and that poisoning in conjunction with cultivation, to be later mentioned, affords almost complete protection from its injuries. To be effective, however, the poisoned spray must be applied at the right times and with great thoroughness. The beetles begin to put in an appearance at about the close of the blooming period. Careful watch should be kept, and upon the first signs of the chain-like feeding marks on the leaves the vines should be thoroughly sprayed with a poison. A sec- ond application should be made in a week or ten days. These appli- cations are intended to poison the newly emerged beetles during their first feeding and before they have deposited their eggs to any extent. If applications be delayed two or three weeks beyond the time indi- _ cated, a considerable percentage of the eggs will have been deposited, and the treatments will lose much of their value. Vineyardists having this pest to contend with should not make the mistake of spraying a little too late, but should have everything in readiness to begin applications upon the first appearance of the beetles. The beetles plainly avoid feeding on foliage sprayed with Bordeaux mixture or arsenate of lead, seeking the unsprayed leaves as much as possible. It is therefore especially necessary to make applications with great thor- oughness, poisoning as nearly as possible the upper surface of every leaf, so that the beetles will be poisoned or forced to leave the vines for food. This desired thoroughness of treatment is not obtained as a rule by vineyardists, and greater care should be exercised in this work. In commercial vineyards the tendency will be to hurry through the @Yearbook U. 8. Dept. of Agriculture, 1895, p. 393, 284 duh work, covering 12 or 15 acres per day, using an insufficient amount of spray. With the spraying machinery in commou use 7 to 8 acres per day is about all that may be covered with the desired thoroughness, and about 125 gallons of spray mixture should be applied per acre. In spraying for the grape root-worm, the poison should always be applied in Bordeaux mixture, which is used in the control of fungous diseases, as elsewhere considered in this bulletin. Theseveral arsenical poisons which may be used are discussed on pages 26 and 27. Destruction of beetles by jarring.—Doctor Felt has made extensive practical tests of jarring the beetles from the vines and catching them’on sheets or special forms of catchers run under the plants or along the rows, and considers this to be an effective plan of con- trolling the pest, the jarrmg of the vines causing many of the beetles to fall in their efforts to escape detection. A sheet of canvas placed on the ground beneath the vines will serve to catch the beetles, but where work of this kind is done on a large scale special apparatus must be provided. There is room for considerable ingenuity in con- structing catchers that will suit individual conditions. Concerning the value of jarring, Doctor Felt says:¢ ‘‘Our experience with col- lectors has demonstrated the practicability of catching the beetles, and we recommend this operation for all badly infested sections, and that the collecting be begun as soon as the beetles appear on the vines in any numbers, say where there are 12 or 15 on one. The operation should then be repeated at intervals of 5 to 7 days till the vines have been gone over two, three, or four times, depending somewhat on the number of insects which are captured. It will be found that it is much easier to catch the beetles on warm days, when it should be done, than in cool weather.” Destruction of pupe by cultivation— While the grape root-worm may be present in well cultivated vineyards, it is much less destructive than in vineyards which receive indifferent cultivation or total neglect. It has long been known that much good may be done in controlling insects which live underground by breaking open their pupal cells and crushing or otherwise killing the helpless pupe. The importance of this work in the destruction of pupz of the grape root-worm was first pointed out by Professor Slingerland in his studies of this pest in the Chautauqua grape belt, and subsequent experiments, confirmed by practical experience, have shown that this is a very important method of reducing the numbers of insects. After the larve have become full grown the great majority pupate but 2 or 3 inches below the surface of the soil, and mostly within a radius of 4 or 2 feet from the base of the vine. In this stage the insects are quite helpless, and are killed in large numbers by a thorough breaking up of the soil around the base of the plants. As stated, the insect will be in the pupal stage in maximum numbers just before the period of blooming of the vines, and the cultivating should be done at this time. In the Ohio, Pennsylvania, and New York grape districts this will be about the middle of June, the time varying somewhat according to the character of the season and of the val The details of this work are very important and require explanation. With the last cultivation in the fall the earth should be thrown to the vines on each side, forming a ridge along the row. The following 2 Bul. 19, Office State Ent. of N. Y., p. 37 (1903). 284 12 spring the larve in making their way toward the surface of the soil to pupate will mostly work up in this ridge of earth, above the surface of the roots, and there enter the pupal stage. The cultivation of the vineyard in the spring should be so adjusted that this ridge of earth may be thrown away from the vines when most of the insects are in the pupal stage, as one of the regular cultivations. An implement known as a ‘‘horse-hoe,”’ generally used in vineyards, may be em- ployed to great advantage in this work; but as it is not practicable to remove the earth from immediately around the vine owing to danger of injury, it is necessary to follow the horse-hoe at once and remove the earth with a hand-hoe. The latter work is also done as a part of the regular vineyard treatment to keep down weeds and grass, and is timed so as to supplement the plowing with the horse-hoe for the insect. Following the removal of the ridge of earth from along the vines, it is well to keep the ground stirred at frequent intervals by means of a cultivator to further insure the destruction of the pupe. GRAPE BERRY MOTH. The larva of the grape berry moth (Polychrosis viteana Clem.) infests the berry or fruit of the grape. The first generation attacks and webs together the grape clusters even before the blossoms open or soon after the grapes are set. Later-appearing larve bore into the green or ripening fruit and produce a purplish spot much resembling in appearance the injury due to the black-rot fungus, with which it is frequently confused. Within the fruit the larvee feed on the pulp and seeds, passing from one grape to another, and several of these discol- ored and shriveling berries will often be found more or less webbed together with numerous particles of larval excrement, and sticky with exuding grape juice. Other insects attack the fruit of the grape, such as the grape-seed insect, (Zsosoma vitis Saunders), whose larvee feed on the seeds, causing the berries to shrivel late in the summer, and the grape curculio (Craponius inexqualis Say), whose injury closely resembles that of the grape berry moth and is considered on a later page. But the principal cause of wormy grapes throughout the country is the larva of the species under consideration. Until recently it was thought that our grape berry moth was introduced from Europe many years ago. But Messrs. Slingerland and Kearfott have shown,* by careful study of this insect and related species, that the insect infesting American vineyards is quite distinct from the EKuro- pean form (Polychrosis botrana Schiff). These gentlemen have also shown that the American grape berry moth does not feed upon sumac, as was formerly held, and consider it very probable that the grape is the sole food of this species. This important fact greatly simplifies the question of its control, for if the species had other food plants -vineyards would be reinfested from outside sources despite thorough treatments. r Distribution and Destructiveness. The American grape berry moth occurs from Canada south to the Gulf and westward to California. It is very generally distributed over this area, and wherever the grape is grown it is more than likely to be a Bul. 223, Cornell Univ. Agrl. Exp. Sta. (1904), 284 > 13 found. For a number of years the pest has been troublesome in Ohio vineyards, and also more or less locally in the Erie grape belt and in New York State. In 1902, according to Slingerland, it was destruc- tive all through the Chautauqua grape belt, and was equally destruc- tive through a large part of this area during the two succeeding years. At the present time the insect is destructive in individual vineyards here and there throughout the Chautauqua, Erie, and northern Ohio grape districts, causing a loss of many thousands of dollars annually. In some vineyards a loss of from 25 to 50 per cent of the crop is not infrequent, and in occasional instances the destruction of the fruit is practically complete. Description and Life History. The grape berry moth is small, the wings expanding not quite one- half inch. The general color is purplish brown, the wings with mark- ings as shown in figure 2. Moths appear in the spring from hibernating pup, beginning about the time the shoots of the grape are pushing out, and continuing to emerge for some weeks. The earlier-appearing individuals deposit their eggs on the blossom clusters, while those com- ing out after the blossoms are shed oviposit on the clusters of young rapes. 5 The minute scalelike eggs of the first brood of moths are difficult to find, as at this time they are relatively scarce, but may be readily detected during summer as a glistening or whitish spot on the surface of the berries. The larve of the first generation feed upon the blos- soms and small berries, webbing them together more or less and producing a more or less ragged bunch of grapes, or the cluster may be almost entirely destroyed. The capabilities of the larve for injury at this time are thus seen to be much greater than is the case with larve of the later broods, by which individual berries are attacked. The spring brood, however, 1s usually quite small; evidently there is a heavy mortality of the insect during the preceding fall and winter. About 3 weeks are required for a larva to complete its growth in summer, when it is about three-eighths of an inch in length, slender, light greenish to purplish in color, the head slightly bilobed, greenish above, and brownish in front, the thoracic feet blackish. When ready to pupate the larve go to the leaves, and a small portion is cut loose, except along one side, and bent over and fastened down with silk. Beneath this a thin, whitish, silken cocoon is spun, and in 3 to 4 days the larva changes to a light greenish brown pupa, from which the moth will emerge in some 12 to 14 days. The larva and curious cocoon and pupa are shown in figure 2, considerably enlarged. Moths of the second and later generations deposit their eggs on the developing grape berries, and the resulting larve bore into these, feeding on the pulp and seeds, the entrance point of the berry being marked by a purplish spot, which renders their detection quite easy. In the Chautauqua and Erie grape belts, and probably in northern Ohio, moths of the second generation will begin coming out and ovipositing about the first week or ten days of July, continu- ing for some weeks, the first and second broods overlapping. By this time the insects will have increased greatly in numbers, and the larvee will be attacking almost exclusively the berries of the grape, 284 14 for which reason their work is much more conspicuous. Second- brood larvee infest the grape during July and August, the later- appearing individuals probably not developing to moths but hiber- nating in the pupal condition. Many of the earlier-appearing insects of this brood appear to complete their life cycle, and moths develop, giving rise to a third generation of larvee. According to the obser- vations of Mr. Fred Johnson, of the Bureau of Entomology, at North East, Pa., practically a full third brood was produced during 1906. On September 7, according to this observer, larvee one-third to one- half grown were very numerous, from 80 to 90 per cent of the ber- ries in many clusters having been injured. Egg shells were very abundant on the fruit, which at this time was beginning to color. Many of the eggs had been parasitized by. what is “probably Tricho- gramma pretiosa Riley, a minute hymenopterous. fly which oviposits in the eggs of many species of lepidopterous insects. A few larve were found in berries by Mr. Johnson as late as October 17, though practically all of the larve had left the fruit. They were found mostly on the leaves, which had already fallen to the ground, where Fig. 2.—Grape berry moth (Polychrosis viteana): a, Adult or moth; b, larva; c, pupa; d, folded leaf, with pupa shell projecting from case cut from the leaf; f, grapes, showing injury, and larva sus- pended by its silk. All much enlarged, except f, somewhat reduced. (From Marlatt.) it appeared the larve went to pupate, scarcely any being found on the foliage still attached to the vines. In the Middle and Southern States it is inferred that there may be each year three full broods, or perhaps more, but as yet the insect has not been studied in this territory. Treatment. Poisons.—The use of arsenical poisons against the first brood of the grape berry moth was recommended by Mr. Marlatt, of the Bureau of Entomology, in 1895.¢ Since this time the recommenda- tion has been amply justified in the experience of numerous vine- yardists, who, in connection ‘with the fight against the grape root- worm, found that their early sprayings for this pest were also con- trolling the grape berry moth. Professor Slingerland reports an instance in which three timely applications of arsenate of lead, at the a Yearbook, U.S. Dept. of Agriculture, 1895, p. 404. 284 15 rate of 10 or 12 pounds to 100 gallons of water, gave almost absolute protection during the rest of the season. Doctor Felt records? that the application of arsenate of lead along with Bordeaux mixture, for the grape root-worm, shortly after the blossoms had fallen and before the erries had grown to the size of a pea, resulted in a decrease of 50 per cent in the injury to fruit by the berry moth. While definite experiments with poisons in the control of this pest appear not yet to have been reported,® the experience above given indicates their great usefulness. As would appear from the life his- tory of the insect, most effective work may be done by destroying the first brood larvx, which feed in the clusters of blossoms and berries. The first treatment should be made just before the blossoms are read to open, and the second just after the blossoms have fallen. A third treatment in a week or ten days is also advisable in badly infested vineyards. In all these treatments special care should be exercised to force the spray well through the clusters of blossoms and young fruit. It will be noted that the second and third treatments for the grape berry moth will coincide with the first and second treatments for the grape root-worm, and the arsenicals recommended for that insect will be equally satisfactory for the grape berry moth. (See page 10.) Picking infested berries.—This practice is often followed by vine- yardists, and is especially directed against larve of the second brood. The infested spotted green berries, which are readily seen, should be carefully searched for and destroyed. This practice will lessen injury from a possible later brood, and if carefully followed would reduce the insects materially in the vineyard from year to year. Bagging clusters.—Inclosing each cluster of grapes in a paper bag soon after the blossoms have fallen should protect them from injury from second and third-brood larve, and would also afford protection from the rose-chafer and from black-rot. This practice is especially useful in the small home vineyard. Gathering fallen leaves.—The fact that the insect passes the winter in fallen leaves has led to the recommendation that these be raked up and burned. From Mr. Johnson’s observations it would appear important to collect these early in the fall, as the pupe are to be found mostly on the 10 or 15 per cent of leaves which fall first, and great care must be taken to collect those leaves more or less imbedded in the soil. After remaining on the ground for a while, probably many of the cocoons break off from the leaves and would thus not be collected with the leaves. It is probable also that many of the insects could be destroyed by covering the leaves with soil early in the fall. @ Bul. 19, Office State Ent. of N. Y., p. 31 (1903). b Since this article was written, definite experiments in spraying for the grape berry moth have been reported by Profs. H. A. Gossard and J. S. Houser in Circular 63 of the Ohio Agricultural Experiment Station. These gentlemen have shown that the insect may be largely controlled by three applications of an arsenical, with the addi- tion of some form of soap to make the spray more adhesive, the time of making appli- cations being practically as recommended above. 284 16 GRAPE CURCULIO. The grape curculio (Craponius inequalis Say) is one of the “snout beetles” belonging in the same family (Curculionide) as the so- called plum curculio. The parent beetle deposits her eggs in little cavities which she eats into the grapes, and the resulting larvee feed upon the pulp and seeds, producing an injury quite similar to that done by the grape berry moth. The beetles cut small, rather char- acteristic holes in the grape leaves when feeding, and the berries often show a purplish coloration at the point punctured in egg-laying, as shown in figure 3. If infested berries be examined it al be readily possible to distin- guish between the grape curculio and the grape berry moth, since the grubs of the former are whitish and quite destitute of legs, whereas the larve of the berry moth have well-developed legs, are greenish in color, quite agile, and likely to escape quickly upon being dis- turbed. See figure 4, showing, at a, an injured berry; c, the ego-cavity and egg beneath skin of grape ; and d, an in- ested berry cut open. Distribution and De- structiveness. The grape curculio is a native species, feeding originally on the wild erape, as it Fig. 3.—Grape leaf, showing feeding marks of grape curculio beetles, does at the present and bunch of grapes infested with larve. Somewhat reduced. time. It has been recorded from Ar- kansas, Missouri, Tennessee, Kentucky, Illinois, Minnesota, Ohio, New Jersey, West Virginia, and North Carolina, and, according to Lintner, it probably occurs in New York State. The Bureau of Entomology has records of its occurrence in Pennsylvania, District of Columbia, West Virginia, North Carolina, and Nebraska. According to Le Conte and Horn, its distribution is ‘‘ Middle, Southern, and West- ern States.”’ The insect was described in 1830 by Thomas Say, but it first attracted attention as a grape pest in 1853 in the vicinity of Cincinnati, Ohio. An account of the species was given in 1867 by 284 a 17 B. D. Walsh, and comments were given on its injuries in IIlinois, Ohio, and Kentucky. Injury by this species is more or less local and inter- mittent. Serious injury was reported by G. R. Wood in 1890 in the vicinity of Sandusky, and in 1891 Professor Webster found it very destructive in vineyards in Franklin County, Ark. For the past eight or ten years the grape curculio has been very destructive in many localities in West Virginia, destroying in many vineyards a large percentage of the crop. The species has been carefully studied by Mr. Fred E. Brooks, of the West Virginia Agricultural Experiment Station, and reported on in detail in Bulletin 100 of that institution. As shown by the experience in West Virginia and elsewhere, the species, under certain conditions, may become a very serious pest, ranking with the root-worm or berry moth. Mr. Brooks has shown that the insect is readily con- trolled with arsenical poisons and, as will be detailed later, (p. 47) treatments for the root- worm and berry moth will also keep this pest under control. Life History and Habits. mou . . ZARE DS sects trav _ The insect passes the winter CRO CPG ES is in the adult or beetle stage, ESOP BO hiding under trash in and near vineyards, especially bor- dering woods. About the time in the spring that the grape is in bloom the beetles come from their hibernation quarters and for the first few days or a week are quite slug- gish, but gradually become more active, feeding on the fohage of the grape until. the Fig. 4.—Work of grape curculio (Craponius inzqualis) berries are about one-fourth rey oe Fe res dit or weovil ovipositing on berry; grown or of sufficient size to _¢,evlatged section of portion of bery, slowing <88 be suitable for receiving the ing ane at work, a be dp enlareed? © Mieuiaeee eggs—according to Mr. ™** Brooks, in 1905, covering a period of about 25 days. This habit of feeding on the exposed portions of the vines some 3 to 4 weeks before egg-laying permits of their ready destruction by arsenical poisons. Late in June, in the latitude of West Virginia, the females begin depositing eggs in the berries, excavating a cavity in which a single egg is Sioa About 4 to 6 days, varying with the tempera- ture, are required for the eggs to hatch, and the resulting larva bur- rows through the pulp, reaching the seed in 3 or 4 days, which is pene- trated and the contents devoured. In 12 to 15 days the larva has become full grown and leaves the berry by eating a hole to the outside, falls to the ground and at once seeks a suitable place for pupation, as under stones, lumps of earth, or just below the surface of the soil. Here an earthen cell is made and the larva transforms to the pupa, the 27724—No, 284—07——3 18 F adult beetle emerging in the course of 18 or 19 days, at first blackish in color with gray hairs, but soon becoming the normal brown color. In figure 5 the parent beetle is shown in dorsal view at a, and a side view at c; the larva or grub is shown in dorsal and ventral views at d and e, and the pupa at f. . The life cycle from egg to adult, as stated by Brooks for a large series of individuals, requires about 35 days. The new generation of beetles feed upon the foliage until fall, when they go into hiber- nation, appearing the following spring, as stated. Mr. Brooks de- termined the egg-laying capacity of 30 beetles, the minimum number deposited by one insect being 63, and the maximum 392, with an average of about 257, the oviposition period extending from June 22 to September 10, a period of 81 days. Oviposition is apparently most active during the first one or two weeks of July. The beetles of the hibernating and of the new generation overlap, and the earlier- Fig. 5.—Grape curculio (Craponius inequalis): a, Adult or beetle, from above; b, head, antenna, and beak of same, from side; c, adult, from side; d, larva, from above; e, same, from below; f, pupa, from below. All much enlarged. appearing individuals of the latter may oviposit, but the result- ing larve will mostly fail to reach maturity. Practically there is but one generation a year in the latitude of West Virginia, while in ae ae a second generation may occur, though it is considered doubtful. Treatment. Poisoning.—The beetles feed freely upon the foliage of the grape in the spring for several weeks before egg-laying begins and continue feeding in the fall after egg-laying ceases along with beetles of the new generation, and it is thus an easy matter to bring about their destruction by arsenical sprays. The treatments advised -for the grape berry moth and root-worm, with perhaps an additional treat- ment 2 or 3 weeks later, will practically control the insect. 284 19 Bagging.—Fruit may also be well protected by bagging the clusters soon after the grapes have set. as already mentioned in connection with the grape berry moth. GRAPE LEAF-HOPPER. Throughout the United States and Canada, wherever the grape is grown, this small leaf-hopper (Typhlocyba comes Say) will almost invariably be found in greater or less numbers infesting the lower sur- face of the leaf, where it feeds and breeds, increasing in numbers as the season progresses, until by late summer and fall the vines are often literally swarming with it. Throughout its extended range the insect may be quite destructive in some localities nearly every year, and is likely to become so elsewhere at any time. The grape leaf- hopper is an insidious pest, often not noticed by the vineyardist until late summer and fall, when the yellow and brown-blotched leaves, falling prematurely, attract attention, by which time the injury has been done. The insects in feeding extract large quantities of liquid food, sucking it out from the interior of the leaf by means of their tube-like mouth-parts. When they are abundant this constitutes a heavy drain on the vitality of the plant. The injury to and loss of leaves prevents the proper Senta of food by the vines; the fruit may be materially reduced in quantity and will lack much in flavor and sugar content. Although the yearly loss to grape growers from the attack of this species is sufficient to place it among the first- class pests of the vine, but little effort ordinarily is made to control it, perhaps principally because no very practicable remedy has until recently been proposed. In the literature of the species there are many records of serious outbreaks of the pest here and there over the country, and recently the insect has attracted more than usual atten- tion on account of serious injury in the Chautauqua and Erie grape belts, where it has been carefully studied by Professor Slingerland.¢ Description and Life History. The adult grape leaf-hopper is quite small, measuring not more than one-eighth of an inch in length. It is very agile, moving with almost equa! facility in all directions, and flies out from the vines often in swarms upon slight disturbance. The general appearance of the insect is shown in figure 6, the back of the insect bemg marked with yellow or red, the exact pattern and color varying much among different individuals and according to season. There are numerous varieties of the insect based on these variations, several varieties often occurring together on the same vine, though more usually insects showing one type of color pattern will be found to predominate. The insect passes the winter in the adult condition in hibernation in trash in and near vineyards, in the edges of neighboring woods, in grass along gullies, in ditches, etc. Early in the spring the insects come from winter quarters and attack almost any succulent vegetation at hand. By the time the foliage of the grape appears they are out in large num- bers and begin to infest the vineyards. These adult hoppers of the @ Bul. 215, Cornell Agrl. Exp. Station (1904). 284 ; 20 hibernating generation feed and breed on the lower or earlier-appear- ing leaves, gradually disappearing as the season progresses, but not before some of their progeny have reached the adult condition. Some weeks are spent by the adults in the spring in feeding before egg- laying begins. Eggs are placed just bore the epidermis in the lower leaf surface, usually singly but also in groups of from 6 to 9, the ege stage, according to Professor Slingerland, lasting from 9 to 14 days. Egg-laying probably continues for two months or more. When just hatched the young hopper is very small, whitish in color, with red eyes, later becoming striped with yellow. In the course of their growth these nymphs molt four times, the white skins being very numerous on the lower surfaces of badly infested leaves, as shown in figure 6, at g. The nymphs feed in the same manner as the parents, sucking juices from the leaves, at first on the lower surface of the older leaves where they were born, but later spread- ing more or less generally over the plant. They are very agile, Fic. 6.—Grape leaf-hopper ( Typhlocyba comes): a, Adult female; b, adult male; c, another form of the species, showing variation in markings; d, newly-hatched nymph; e, last stage nymph; f/f, pee tac of injured leaf; g,cast pupa skins. a-e, Much enlarged; g, less enlarged; f, reduced. (From Marlatt.) running in all directions, but do not leap or hop. In New York State Professor Slingerland found that from 30 to 35 days were required for their development in summer to the adult, and that there is but one full generation and a partial second brood of nymphs each year, the individuals of this partial second brood probably not maturing before frost. In warmer parts of the country two full generations or more are probable, since Gillette has shown this to be the case for Colorado and Townsend for New Mexico. By late summer the insects are often exceedingly abundant, and all stages are to be found on the leaves. The continued effect of their feeding is very apparent, the leaves being yellow and brown-blotched, the older ones most affected (figure 6, f). Feeding continues until the approach of cool weather, when the ‘‘hoppers”’ seek suitable hibernation quarters, as stated. 284 21 Remedial Measures. The grape leaf-hopper has proved to be a difficult pest to combat aheeessr ily Various practices have been proposed, such as the use of trap lanterns to burn at night, the raking and burning during winter of fallen leaves and trash in vineyards, the use of sticky shields or fans to catch the adults as they fly from the vine on being disturbed, and in California the use of insect nets for the same purpose. Extensive field experiments were made by Professor Slingerland and his assistants in 1902 in Chautauqua vineyards against this pest, and fully recorded in Bulletin 215 already cited. He found that large numbers of the hibernated adults could be caught on sticky shields carried along each side of the row, the insects being frightened out by disturbing the vines. This work is done early in the season, before oviposition takes place to any extent. A light wooden frame is made, 7 or 8 feet long by 4 feet high. To the crosspiece at the bottom, which should be up from the ground about a foot, are fastenéd several stiff wires of the shape of a hayrake tooth. These are fastened so that the poimts curve inward and downward to the ground at base of plants when the shield is held in place beside the vines. The whole framework, including the wires, is covered with oilcloth which is coated with a sticky substance, made by using melted resin, 1 quart, and castor oil, 1 pint. Early in the season the insects will be found mostly on the lower leaves and the frame need not be high. As the higher leaves are invaded the height of the frame must be increased. In controlling the insects in this way it is very important to catch the over-wintering adults before egg laying has begun, thus greatly reducing the number of progeny to appear later, and the operation of catching the insects must be repeated at frequent intervals. Extensive tests with sprays were also made, and it was found prac- ticable to destroy the young wingless hoppers or nymphs with a whale- oil soap solution, the soap being used at the rate of 1 pound to 10 gallons of water. The spraying must be done very thoroughly, covering the under surface of the leaves, as only those nymphs are killed which are actually hit with the spray. This work should be begun when it is observed that the young are becoming common. In the Chautauqua and Erie grape belts this will be early in July. There will be less foliage to treat.at this time than if the work be deferred until some- what later. Repeated applications may be necessary, especially if the work is not thoroughly done. It has been noted by Mr. Fred Johnson, of this Bureau, that whale-oil soap leaves a stain on the fruit at picking time, greatly lessening its market value for dessert purposes. It is likely that an 8 to 10 per cent kerosene emulsion could be used, which would obviate this difficulty, and would prove equally effective in killing the young hoppers. Thorough cleaning up of fallen leaves and trash in vineyards durin the winter will undoubtedly destroy many hibernating adults, an if this work be extended to adjacent areas where the insects are likely to find shelter, the reduction in their numbers will be materi- ally greater. Where practicable the burning over of adjacent mead- ows, wood lots, and spaces along fences is very advisable. It has been observed that in vineyards in which clean culture is prac- ticed, all grass and weeds being kept down throughout the season, 284 22 the “‘hoppers”’ are notably less abundant than where this practice is not followed. The absence of suitable hibernation quarters in the vineyard causes them, largely, to migrate elsewhere, and vineyards recelving such care are much less seriously infested the following spring and summer. The grape leaf-hopper secures its food by sucking juices from the interior of the leaf, and arsenical poisons useful against the grape root- worm and the grape berry moth are quite useless against this pest. GRAPE LEAF-FOLDER. Observing grape growers have often noticed, especially during midsummer and later, grape leaves folded together, the interior (upper) surface of the leat being more or less skeletonized, and within the fold a slender larva, which, upon being disturbed, is apt to wriggle out and fall or hang suspended by a thread. This insect, the grape leaf-folder (Desmia funeralis Hiibner; see fig. 7),is widely distributed and a few are to be found in vineyards almost every year, while here and there through- out their range they may be so abundant as to do serious in- each year in the more northern States and three or possibly more in theSouth. The insect winters in the pupal stage in the folded and fallen leaves, the moths appearing in the spring shortly after the foliage puts out, and the eggs are placed in small patches here and there on the vine. Upon Fig. 7.—Grape leaf-folder (Desmia funeralis) : a, Male hatching, the youn larve at- moth and enlarged antenna of same; 6, female : 2 A moth; c, larva; d, head and thoracic segments of tack the folia e, olding the grape leaf folded by lnrea. From Marlatt) leaves as stated. Mr. Johnson has observed that larvee of the first brood may attack bunches of grape blossoms and young fruit in a way similar to the grape berry moth. In 3 or 4 weeks the larve are full grown and transform to pupz within the folded leaves, moths emerging some 8 or 10 days later. By midsummer and fall the insects may become quite abundant, and in badly infested vineyards the folded leaves are everywhere in evidence and are quite conspicu- ous from the color of the lower surface. In the fall the larvee pupate in the folded leaves and pass the winter in these on the ground. Treatment. Where the insects are but moderately abundant it will be quite practicable to search out the folded leaves and crush between the hands the larve or pupe within. The destruction of the first brood in this way would greatly reduce the number of the insects later in the season. 284 jury. There are two broods. a 23 Vines sprayed with arsenicals for the root-worm and the berry moth will be well protected from the leaf-folder, for in this way the majority of the leaves will be sufficiently poisoned to insure the destruc- tion of the larve and prevent the folding of the leaves. After a leaf has been folded the larva is practically safe from poisoning. As the’ winter is spent in the pupal stage in the leaves on the ground, many of the insects may be destroyed by collecting and burning the fallen leaves, as recommended in the case of the grape berry moth and the leaf-hopper. GRAPEVINE FLEA-BEETLE. Early in spring, as the buds of the grape begin to swell and burst, these may be scooped out or entirely consumed by a small blue or greenish beetle (Haltica chalybea Lliger), measuring about one-fifth of an inch in length, of robust shape, with thick thighs, and jumping Fig. 8.—Grapevine flea-beetle (Haltica chalybea): a, Adult or beetle, with more enlarged leg at right; b, larva; c, larve and beetles on foliage; d, injury to buds; e, beetles killed by fungus. a, b, Much enlarged; c, d, e, about natural size. (From Marlatt.) readily from the vines upon being disturbed (see fig. 8). When the beetles are abundant all of the buds on the vines may be quite de- stroyed, greatly retarding leafing out or even causing the death of the plant. Later the young foliage is eaten by the beetles, the females depositing their eggs more or less on the leaves, but largely, according - to Slingerland,® in cracks in the bark at base of buds, between bud scales, or even in the holes which have been eaten into the buds. The resulting larvee feed on the leaves of the grape, mostly on the upper surface, and are thus readily destroyed with sprays. In 3 or 4 weeks the grubs have attained full growth; then, dropping to the ground, they make an earthen cell an inch or so below the surface, and trans- form to pup, from which the adult beetles will emerge in the course of 1 or 2 weeks. The new brood of beetles feeds upon the grape and other plants, going into hibernation in the fall and appearing the next @ Bul. 157, Cornell Univ. Agrl. Exp. Station (1898). 284 24 spring to attack the buds of the grape, as stated. In the Northern States Slingerland’s studies have shown but one generation of the insect each year. In the South two or more generations annually are supposed to occur, but definite evidence on this point is wanting. The flea-beetle is native to North America, and occurs very generally throughout the eastern half of the United States, its western limits being Minnesota, eastern Nebraska, Kansas, and Texas. Its natural food is undoubtedly the wild grape, though numerous other plants are fed upon, as plum, apple, pear, quince, blue or water beech (Carpinus), elm, ete. Treatment. In vineyards which are regularly sprayed with arsenicals and Bor- deaux mixture the flea-beetle will be effectively kept in check. The first application for the berry moth before the plasoms open, together with the application made after the blossoms fall, will destroy the larvee, since these feed almost exclusively on the upper surface of the leaves. The insects thrive best in neglected vineyards, and may become quite abundant and destructive locally. Where it is desired to treat for this insect only, the vines should be thoroughly sprayed with an arsenical just as the buds are beginning to swell, or some- what earlier. A close lookout must be kept for the first signs of the beetles, and the poison must be applied immediately. The delay of a day or so may mean the loss of the buds, and hence of the fruit crop. In the small home vineyard it will be practicable to search out the beetles and remove them by hand, doing the work in the morning when they are less agile. As stated, the destruction of the larve when feeding on the foliage later will be very easily accomplished by spraying with arsenicals. It will also be quite practicable, as stated by Doctor Howard, to jar the beetles from the vines on canvas frames placed beneath, which should be kept saturated with kerosene. ROSE-CHAFER. About the time of blooming of the grape in the spring the rose- chafer (Macrodactylus subspinosus Fabricius) may suddenly put in an appearance, often in enormous numbers, the long, spiny-legged, awkward, brownish beetles literally covering the plants, feeding at first upon the blossoms, but later attacking the young fruit and foliage, the leaves being eaten bare, except the larger veins (see fig. 9). This insect is a very general feeder; it attacks practically all fruits—e. g., apples, plums, cherries, peaches, etc.—as well as various vegetables, grains,and grasses. Many ornamental plants, such as Spirea, Deut- . zia, and roses, are attacked, and its injuries ‘to the last-mentioned have led to the use of the common name of ‘‘rose-chafer”’ or ‘‘rose- bug,” though it is perhaps now most commonly complained of from its injuries to grapes and other fruits. When abundant, the beetles may do serious injury in vineyards, quite destroying the blossom clusters or the newly set fruit. Berries not actually devoured are often so marked by the beetles that they become misshapen and crack as they grow, the seeds often protruding. After 3 or 4 weeks of feeding the beetles may disappear almost as suddenly as they came. 284 25 The rose-chafer is rather widely distributed, occurring from Canada south to Virginia and Tennessee and west to Colorado. It is recorded also from Oklahoma and Texas, though west of the Mississippi it is apparently not very injurious. In the New England and Central States it is more abundant, and is most troublesome perhaps in New York, Pennsylvania, New Jersey, Delaware, Maryland, Virginia, and Ohio, large outbreaks in ruinous numbers occurring more or less locally where the soil is light and sandy. Fig. 9.—Rose-chafer ( Macrodactylus subspinosus): a, Adult or beetle; b, larva; c, d, mouth parts of same; e, pupa; f, injury to leaves and blossoms of grape, with beetles at work. a, b, e, Much enlarged; c, d, more enlarged; 7, somewhat reduced. (From Marlatt.) Breeding Grounds. The insect lives in the larval stage underground, feeding on the roots of various plants, especially on the roots of grasses. Doctor J. B. Smith found larve in abundance in a vineyard in New Jersey and in a blackberry patch, feeding apparently on the roots of grasses and weeds which grew sparsely between the rows, and larve were still more numerous under the sod bordering the vineyard. In an adjacent meadow, where the soil was heavier and less sandy, no larvee could be found. In general, the insects breed principally in light sandy soils, especially in meadow lands, but also in other places where there is more or less of growth of grass and weeds, and, to a less extent, in cultivated ground. Wet, clayey, or compact soils do not furnish desired conditions for the insects, and from the fact that they are largely confined to the lighter soils it becomes practicable to reduce them greatly by planting these to annual crops which receive thorough cultivation. 284 26 Life History. The beetles deposit their eggs singly, burrowing beneath the soil, laying, according to Doctor Smith,? from 12 to 20 eggs. The result- - ing larve feed upon the roots of various grasses and possibly weeds and other vegetation. They are mostly full grown by fall, and burrow below the frost line, where the winter is spent. With the coming of spring the grubs ascend toward the surface and enter the pupa stage, from which in from 10 to 30 days, varying with the temperature, the beetles develop and attack the grape and other plants, as stated. - There is thus but one generation each year, the principal injury of the insect being done during the 3 or 4 weeks of its life as a beetle. Treatment. The rose-chafer is an exceedingly difficult insect to combat suc- cessfully. When the insect occurs only in moderate numbers, arseni- cals will be reasonably satisfactory; but when it occurs in swarms, the plants are reinfested as fast as the insects are killed. It is pos-. sible, however, that a heavy application of arsenate of lead, say 5 to 6 pounds to 50 gallons of water or Bordeaux mixture, will largely pro- tect the vines, and this plan should be tested by vineyardists con- fronted with this pest. Very thorough applications should be made upon first signs of the insects and repeated as necessary. Many different substances have been applied to vines to render them obnox- ious to the beetles, but none of these has proved to have any special value. Perhaps the method most generally relied upon is picking or jarring the beetles from the vines. In the latter work an umbrella- shaped frame with a canvas or oil cloth covering, with a can of kero- sene at the bottom, is frequently used, being held under the vines, which at the moment are sufficiently shaken to cause the beetles to fall. Jarring or hand-picking must be done every morning, or, better, twice a day, during periods of severe infestation. The numbers of this insect may be considerably lessened by re- stricting its breeding grounds. In vineyards on sandy or light soil especial care should be taken to keep the rows and surroundings free from weeds and grass, upon the roots of which the larve feed. Sandy meadow lands in the vicinity of vineyards should be broken up and cultivated to annual crops, and in this work the cooperation of vine- yardists throughout a neighborhood is especially important. Bagging grapes as soon as the fruit has set is often practiced, and affords protection not only against further injury from the rose- chafer, but also from the grape berry moth, the grape curculio, and fungous diseases of the fruit. INSECTICIDES.? ARSENICALS. Arsenicals, applied in the form of a spray, are effective against the grape root-worm, the grape berry moth, the grape curculio, the grape leaf-folder, and other insects which devour the foliage a2Bul. 82, N. J. Agrl. Exp. Station (1891). bFor a more extended account of insecticides, see Farmers’ Bulletin 127, U. 8S. Dept. of Agriculture, by C. L. Marlatt. 284 —o 27 and fruit. The arsenical is best used as an ingredient added to the Bordeaux mixture, which is the standard remedy for the control of fungous diseases. When an arsenical is used simply in water the vineyardist should always add, to each 50 gallons of the liquid, the milk of lime made from slaking 2 to 3 pounds of good stone lime. Paris green.—This is used at the rate of 1 pound to each 100 or 150 gallons of liquid, whether water and milk of lime or the Bordeaux mixture. Paris green should be worked into a paste with water be- fore being added to the liquid in the spray tank, to prevent its ad- hering in small lumps. When used with Bordeaux mixture, the latter will probably serve to hold it well on the vines, giving results perhaps equal to those produced by arsenate of lead. Scheele’s green.—This arsenical is similar to Paris green, being the simple arsenite of copper containing no acetic acid, and hence consid- erably cheaper. It is a much finer powder than Paris green and re- mains in suspension longer. It is used in the same way and at the same strength recommended for the former poison. Arsenate of lead.—There are now numerous brands of arsenate of lead on the market, and vineyardists should be careful to buy an effi- cient and safe kind. Some preparations sold as arsenate of lead con- tain an amount of free arsenic dangerous to foliage, and an unneces- sary amount of water may also be present, thus lowering the quantity of poison when used at a given strength. A proper arsenate of lead should contain no free arsenic and should have as much as 50 per cent actual arsenate of lead. Arsenate of lead is used at the rate of 3 to 6 pounds to each 50 gallons of liquid, and, as it comes in the form of a putty-like paste, must be worked free in a little water in a bucket or other suitable vessel before it is added to the spray tank. It may be used much stronger than any other arsenical and it adheres well to the foliage. For these reasons it is preferred by many vineyardists. Arsenite of lime—This is much the cheapest of the arsenical poi- sons. On apple it is stated to be very satisfactory, and it should be equally so ongrape. It seems not yet to have been used to any ex- tent on grape, and should be tried first in a small way. It may be prepared at home according to the following formula: VINE: BT SGT Ds ope SO A SN at a a a ole ele, eae See pounds.. 1 SL ISU pCi ya CUCU ag SOT eld eae ess Open Men eget” Pie AL eer c= douse s4 VEL cages SE Sate er I Rita Ae oN, OO Ia airs NR Fae eed gallon.. 1 All of the ingredients are boiled together for a few minutes or until dissolved, and any water lost by evaporation should be restored. This constitutes a stock solution, 1 pint being used with each 40 or 50 gallons of Bordeaux mixture. When it is used in water the vineyard- ist must add the milk of lime made from slaking 2 to 3 pounds of good stone lime, which is necessary to produce the arsenite of lime. CONTACT REMEDIES. For insects which secure their food by sucking the juices from the plant, such as the grape leaf-hopper and aphides, contact insecti- cides must be used. Two such insecticides are whale-oil soap solution and kerosene emulsion. These preparations are not ordinarily used in Bordeaux mixture. They are sprayed on the vines in the usual way. 284 28 Whale-oil soap.—F or vines in foliage, whale-oil soap is used at the rate of 1 pound to 8 or 10 gallons of water. There are several grades of this article on the market, but a potash whale-oil soap is best, especially one that does not contain more than 30 per cent of water. Kerosene emulsion.—This doubtiess will be equally satisfactory as a spray against the grape leaf-hopper, and may be prepared as follows: Whale-oil..orotherisoap: 14.1115). 25.00 THEME: US: BEE pounds.. 24 Kerosene (160 flash test). 40 2 oe yee eee Plea gallons.. 5 Water GOmmOa Ke: Ga. Bo. cae Sie ce coe a OEE eee eee doreeeaou The soap is dissolved in 6 to 8 gallons of hot water, and the kerosene is at once added. The whole is then thoroughly emulsified by the use of a hand pump, pumping the liquid back upon itself for 8 or 10 minutes or until a creamy-white emulsion results. This, when diluted with the required amount of water, will contain 10 per cent of kero- sene, which strength should be effective in destroying young hoppers. without injuring the foliage or the fruit. If a smaller quantity of emulsion hat 50 gallons is desired, it may be made, simply observing the proportions given. FUNGOUS DISEASES. The fungous parasites of the American varieties of grape are indig- enous, and came originally from the native wild vines. With the gradual extension and development of the grape-growing industry there has also been an increase in the distribution and destructiveness of these fungous diseases. The conditions which necessarily obtain in commercial grape culture have disturbed the equilibrium which had become established between the vine and its parasites in their wild state, and have facilitated the production and distribution of the dis- eases. In the selection and breeding of the grape attention has been devoted chiefly to the improvement of the fruit, and this has appar- ently resulted in adecrease of the natural powers of resistance to disease originally possessed by the wild vines. In certain sections of the country where grape growing was once a profitable industry it has largely been abandoned, chiefly on account of the great loss caused by disease. The amount of loss from fungous diseases of the grape in the eastern half of the United States during the past season (1906) is estimated at from 15 to 20 per cent of the entire crop. In some localities it reached 40 to 50 per cent, and in some particular vineyards where there was promise of a crop of 4 or 5 tons per acre the loss was total, while in one favored region the loss was not over 5 per cent. Injury due to fungi depends largely upon weather conditions. The conditions most favorable for the development of the majority of the fungous diseases are excessive moisture and heat. The general physiological condition of the vines is also important. Vines which are kept thrifty and vigorous by proper care and cultivation are not 284 29 likely to suffer so severely from most diseases as those which are neglected. The principal fungous diseases in the order of their importance are black-rot, downy mildew, powdery mildew, anthracnose, and ripe-rot. There are also other diseases, which will be referred to later, but they are either not of sufficient importance to deserve much attention here or else their treatment is not yet satisfactorily determined. BLACK-ROT. Black-rot is the most generally distributed and destructive fungous disease of the grape in the region east of the Rocky Mountains. It - is caused by a parasitic fungus known as Guignardia bidwellia (Ell.) V. & R. It gains entrance to the plant by means of minute germs called spores. These are borne in small black spore cases, and can Fic. 10.—The black-rot fungus (Guignardia bidwellizi): a, A portion of an affected grape, showing the pustules in which the spores are produced (slightly magnified); 6 a section of one of these pustules very highly magnified, showing the manner in which the summer spores are produced and dis- charged; c, a sac containing winter spores; d, single winter spores very highly magnified. not be seen with the naked eye. They are distributed chiefly by the wind and rain. Two or more forms of spores are produced, as shown in the accompanying illustration (fig. 10, 6). When these spores come in contact with the young and tender parts of the vine, under favorable conditions, they germinate and produce a slender tube, which penetrates the tissue and may destroy it. This disease attacks the leaves and shoots, as well as the fruit. It usually makes its first appearance on the leaves and young shoots, producing reddish-brown dead spots. The fruit may be attacked when young, but usually the disease does not attract attention until the berries are half grown or more. Brown or blackish spots first 284 30 appear; these spread and soon affect the whole berry, which becomes black and shriveled, as shown in the accompanying illustration (fig. 11). These diseased berries remain attached to the vine, and their surfaces become covered with minute black pustules, which contain the summer spores of the fungus. During the winter and spring another form, called the winter, or resting spore, is produced upon these old, shriveled berries (fig. 10,c, d). These spores help to carry the disease over from one season to another. This fact would indi- cate the desirability of destroying, by burning, all diseased fruit, as well as leaves and prunings, as early in the spring as possible. Treatment. This disease can be effectually con- trolled by thorough spraying with Bor- deaux mixture. Five or six applications are usually necessary during the season, the first being made just before the buds open. For the last one or two applica- tions, some fungicide which does not stain the fruit should be used. Burgundy mixture is recommended for this purpose. Full directions regarding the preparation of the fungicides and the times of appli- cation will be found later. Covering the bunches of grapes with paper bags soon after the blossoms fall is a means of preventing black-rot and most other fungous parasites. It is usu- ally regarded as too laborious and expen- sive for large vineyards, but may be profitably practiced where only a small number of vines are grown. DOWNY MILDEW. Downy mildew (Plasmopara viticola (B. & C.) Berl. & De Toni) in certain seasons and in northern localities some- times causes more loss than black-rot Tie 11 “A bundh ‘or Bépae adstropa 2Dd ds @ close mival for first place among by black-rot. the fungous enemies of the grape. It attacks all the tender growing parts of the vine. Usually it is at first most noticeable on the foliage, pro- ducing greenish yellow, irregular spots upon the upper surface, which become reddish brown. At the same time there appears on the under surface of the leaf a thin, loose, white, downy growth, suggestive of hoar frost (fig. 12). This growth consists of the fertile fungous fila- ments bearing the summer spores (fig. 13, a, b), which under favorable conditions are distributed by the wind and water to the berries and other parts, where they germinate, penetrate the tissues, and con- tinue their destructive work, The young shoots are also frequently attacked and killed, Hiy Oe 284 31 The fruit, if attacked when young or only partly grown, shows first a brownish spot, and later becomes covered with the gray, downy erowth of the fungus. This form of the disease is sometimes called “oray-rot’’ by vineyardists (fig. 14). When the berries escape the disease until they are half grown or more it appears as a brownish or brownish purple spot which spreads and soon involves the whole berry. The affected fruit becomes soft and wrinkled and falls to the ground when. disturbed. This stage of the disease is sometimes called ‘ brown-rot.”’ Fig. 12.—A grape leaf attacked by the downy mildew (Plasmopara viticola), showing the appearance of the leaf above and below. Besides the summer spores mentioned, there is also produced within the diseased tissues another form of reproductive body, some- times called a winter, or resting, spore (fig. 13, ¢). These spores are produced in much smaller numbers than the summer spores and are provided with a rather thick, dark-colored outer covering apparently intended for their protection during the winter. : 284 32 This disease, like the black-rot and many others, develops most rapidly and does most injury during hot, wet weather. Treatment. It is desirable to destroy as many as possible of the diseased leaves, shoots, and berries, which may contain the winter spores. Thorough spraying, as recommended for the black-rot, will effectually control this disease. POWDERY MILDEW. The powdery mildew (Uncinula necator (Schw.) Burr.) rarely causes great loss to American varieties of grapes. It is most severe on the European, or vinifera, grapes. This mildew belongs to a group of fungi quite different from the downy mildew. Fic. 13.—The fungus causing downy mildew: d, Fertile filaments of the downy mildew fungus, showing the Fic. 14.—A bunch of young grapes par- manner in which the summer spores are borne; b, two tially destroyed by “gray-rot.” This summer spores; ¢, a winter, or resting, spore. (All is a form of the downy mildew affecting highly magnified.) the very young fruit. It differs from all other parasites which attack the grape in its superficial habit of growth. The filaments of the fungus do not invade the tissues of the plant to destroythem. The parasite obtains its nutriment by means of sucker-like organs which penetrate the cell walls of the surface layer of tissue only. The fine, white filaments of the fungus, which constitute the vegetative portion of the parasite, 284 33 johns over the surface of the leaves, shoots, and fruit, and send up short, irregular branches upon which immense numbers of summer spores are produced in short chains (fig. 15,a). These are most notice- able upon the upper surface of the leaf, giving it a fine gray, powdery, or mealy appearance. Finally the affected part of the leaf becomes light brown, and if the disease be severe the leaves fall. The fungus produces a similar appearance upon the young shoots. Berries which are attacked take on a gray, scurfy appearance, become specked with brown, and fail to develop further. Affected grapes when nearly half grown sometimes burst open on one side, exposing the seeds. The fruit does not become softened and shrunken as when attacked by the downy mildew. Besides the summer spores, winter, or resting, spores are also pro- duced in the latter part of the season. These are borne in sacs which fo F H e 4 \ 1 ? e H H [ SN ‘ee f AQ \ A 4 \ q 4g > 4 — 5) —e / VA ss She y, C) PR SS ye y. Zoo LEY, Sy 4 t 2 Bes 7 SO R Niitiitelles FF a uu ul lu TMH it ez i Du MUU ue | haw FI 5. Fig. 31.—A large hand spray pump with double vertical cylinders Fig. 32.—A large hand spray pump with double horizontal for use with tank outfits. cylinders for use with tank outfits. The accompanying illustrations (figs. 34 and 35) show two grape leaves to which Bordeaux mixture has been applied. Figure 34 shows a leaf properly sprayed. Figure 35 shows a leaf which has been sprinkled rather than sprayed. Too much of the mixture hay- ing been applied, it has run together in drops or fallen to the ground and been wasted. The leaf shown in figure 35 is, however, covered better than is generally the case in vineyard spraying. Thorough work is absolutely necessary if satisfactory results are to be secured. The nozzles should be carefully adjusted and directed, and should 284 47 also be watched to see that they do not clog. The rods with adjust- able nozzles, such as shown in figure 30, have given best results. The team should be driven slowly and ‘il at the proper distance from the vines. = 7 Time of application. First application —In case fungous diseases are caus- ing serious loss, or the vineyard has not been sprayed before, a thorough application of the strong Bordeaux mixture mentioned (6-3-50 formula) should be made "G33 A yer” just before the buds open. For the grape-growin regions of New York, Pennsylvania, Ohio, and Michigan this will usually be about May 1. If injury from the grapevine flea-beetle is anticipated, an arsenical should be added to the mixture. Second application—This should be made just before the blossoms begin to open, which will be about the 1st of June for the States men- tioned. The ordinary Bordeaux mixture (5-5-50 furmula) should be used, and with an arsenical added the spray will be effective Fic. 34.—A grape leaf properly sprayed, showing the surface covered with minute drops of the Bordeaux mixture. against the grapevine flea-beetle, the rose-chafer, grape curculio, and the first brood of the grape berry moth and the grape leaf-folder, respectively. Third application This should be made as soon as the blossoms fall, using Bordeaux mixture as above and an arsenical to give 284 48 further protection against the insects mentioned and to poison the grape root-worm, the beetles of which are at this time just beginning to appear. Fourth application.—This should be made within 10 days after the third application, using Bordeaux mixture as above and an arsenical. » This and the preceding applications are especially important for the erape root-worm and the grape curculio, and will also afford further protection against the grape berry moth and the leaf-folder. For the insects first mentioned, it is very important that this application be delayed not longer than 10 days after the third. | Fic. 35.—A grape leaf improperly sprayed. ._The mixture has been sprinkled upon the leaf instead of being sprayed ina fine mist, and the surface is not evenly and properly covered. Fifth application This should be made two weeks after the fourth, using the Burgundy mixture recommended, and no arsenical. Sixth application—This should be made about two weeks after the last application, using the Burgundy mixture only. QUANTITY OF MIXTURE REQUIRED AND COST OF TREATMENT: One hundred and twenty-five gallons of Bordeaux mixture is usually sufficient for a single application to an acre of vines of average size. Where the vines are large and the foliage dense, as much as 150 gal- lons may be necessary for a thorough application. It will be better to use too much of the mixture than too little. The cost for labor and material will vary from $12 to $15 per acre for six applications, including an arsenical poison for biting insects. 284 O Issued May 10, 1907. U. S. DEPARTMENT OF AGRICULTURE. FARMERS’ BULLETIN 290. THE COTTON BOLLWORM: A Summary of its Life History and Habits, with Some Results of Investigations in 1905 and 1906. BY F. C. BISHOPP anp C. R. JONES, Of the Bureau of E ntomology. WASHINGTON: GOVERNMENT PRINTING OFFICE. ESOT. ‘Ua eu yi WAT in) Lay > eT es LETTER OF TRANSMITTAL. Unitep States DeparTMENT OF AGRICULTURE, Bureau or EntToMowoey, Washington, D. C., February 26, 1907. Str: I have the honor to transmit herewith the manuscript of an account of the cotton bollworm, by F. C. Bishopp and C. R. Jones, of this Bureau, based on investigations conducted during the years 1905 and 1906, and to recommend its publication as a Farmers’ Bulletin. The investigations are in continuation of those reported for the years 1903 and 1904 and published as Farmers’ Bulletins 191 and 212 and Bulletin No. 50 of the Bureau of Entomology. Respectfully, L. O. Howarp, Entomologist and Chief of Bureau. Hon. James WItson, Secretary of Agriculture. 290 (3) CONTENTS. Page PEST GRE NELNG ALCON So oon tes eek ae we SG Pg A Oa ee cet, A vi [LAURE COVED Se 2 Sete ee Den SES RS OE ee i SO Nr SR eS tN ee 8 Les C08 CREAR eS Sas BA a a I i cal 2 lel SDN Bae PR re nt EMS PN Bs ae 8 BUST UT Vitis eee ees tee DN a es ed ee ee ee eee 8 IE UUESS (Oe) ose eee es ie ame Be et bE PS ek Me aD Cag ED ie A ee ene ee Re ee 8 ARETE SUCH UA fee ee eases Lele EE eg a Oe ae Le 10 ieeesteer hie Cte MR CCC YC] Cee mee eects ene ee” eee ee et a Se ee 10 EMBED reel pe eres ee eteod rae ee) eet Se te oe 10 ECU BRGCRIMEOR meee 8 wea el he 2 ee eee a Me at Vo Sere i PED ake SUR Coat CMTE CBE Vee me mere anes TOES NSE 2 i oT 1 eS erry | kes oe Joe 5s 12 TAT TSE TS |e SS sepals Eres Da eee SO a re Ee yd 12 Means of control______ cals aie Bg Gt pa Nee Se FA oe igs SUL Sa) Dee el ST 14 apiece MIE CMO se = eet? Cee TTT oye ay TS Spee) ) “eee te ee ie 14 SS a a ee nee) A. west Bem 16 “LS TERY Geb Cig) 0) SR rt SS ee ee Se See Ee oo Ae Ea et 18 LP TYGIRE,, SoC TELE 9118 (075 8 6 Se ce Ae ee Rags edad Papier Lela RR LAS Ue 20 PNNTSARAT GHSERNN OE Es As gee 21 IEG LRN OjSI Og Ob Re 2h S00 Ok ee alee en A Rr Le ee NE eRe eae Lap SNC 8 oa? 23 Summary remarks concerning the use of fertilizers___-______________ 24 TUTE CTICH TNF Am 07 GE CSS UG 9) 0S a 9 te a AD Os Ni eT IR ite UES 25 FeOstGCSLOhDOIsOn: Ox PeCLMOIGIES 22 a2 40 28 as 2 a Ee a as 25 iP reloO neem DCtimMentse eas: ise 0 ee a eee ee 20 Aree be GMa CLONE mer ee ea Se a eee 28 The more important natural factors in bollworm control_______-_-__-_ 29 ROE EC SLED GOT Swe eee cee ee: ee ee ees 31 290 (5) LELUS TRATIONS. Page. Hires 1. Nee of bollworme: 203 =e. es ee Ee eee 3 2. Cross section through the soil, showing pupa of bollworm in its DBO We 22 ee es a a ee a ee +> oo DONWON MOPR ss i ee ee 10 4. Area of bollworm injury in Texas, Indian Territory, and Okla- mom as GOS. 22 SA a Ee SY in 15 (6) THE COTTON BOLLWORM. INTRODUCTION. The cotton bollworm (Heliothis obsoleta Fab.) is one of the oldest, most widely distributed, and most destructive of injurious insects. Its presence has long been felt by cotton planters throughout the South, and since about 1850 much attention has been devoted to it by entomologists. The more important results of the earlier investigations conducted by the General Government were published in the Agricultural Re- ports of the Patent Office for 1854 and 1855, in Comstock’s Report on Cotton Insects (1879), and in the Fourth Report of the United States Entomological Commission (1885). More recently Bulletins 24 and 29 (old series) of the Division of Entomology were issued in 1891 and 1893, respectively, as the result of supplementary investigations. In 1896 Dr. L. O. Howard gave a very comprehensive account of this species in Bulletin 33, Office of Experiment Stations, which was later revised and made available for general distribution as Farmers’ Bulle- tin 47. Since 1903 Congress has provided for a continuous investigation of the bollworm, on account of the serious injury inflicted by it in the western portion of the cotton belt during the past few years. The results of this investigation have been published in Farmers’ Bulle- tins 191 (1904) and 212 (1905) ; and in Bulletin 50 (new series) of the Bureau of Entomology, in which Messrs. A. L. Quaintance and C. T. Brues give a very complete and concise account of the insect to date. The dissemination of knowledge resulting from the general distri- bution of the several publications upon the life history, habits, and best means of control has not been entirely void of results. Never- theless the great majority of planters have Bp ese its ravages to con- tinue PR hsckel from year to year. The crisis in cotton culture in Texas, brought about by the intro- duction and spread of the well-known cotton boll weevil, has awak- ened the planters to the importance of reducing injury by other cotton pests, in order to better their chances of securing a fair crop of cotton - in spite of the presence of the boll weevil. Fortunately the methods found to be of most value in boll weevil control and those which are being largely adopted throughout the weevil-infested area of Texas are also of paramount importance in lessening bollworm ravages. 290 (7) 8 ‘LIFE CYCLE. There are four distinct stages in the life cycle of the bollworm, as is the case with all butterflies and moths—namely, the egg, larva, pupa, and adult. The egg.—The eggs of the bollworm moths are deposited upon various plants and other objects, mainly, however, on the favorite food plants of the larvee—corn, cotton, and less frequently on toma- toes and tobacco. They are quite small (about one-fiftieth of an inch in diameter), whitish objects, and may usually be seen in numbers on fresh corn silks or scattered about on the leaves of corn or upon the foliage and fruit of cotton, though in the latter instances they are less easily seen, owing to their pale color. The accompanying figure (fig. 1) shows the peculiar sculpturing of the egg surface as seen with the aid of a magnifier. The number of eggs laid by a single moth varies from about 300 to nearly 3,000, with an average of about 1,100. The temperature has a decided influence upon the length of the egg stage. It varies from two and one-half days during the summer months to eight days or even longer in the spring and fall. : The larva.—The larva is the destructive igs tlhe Beene eee * ae ana Stage of the insect and, of course, the one topviews. Highlymagnified(irom most generally noticed. When first hatched Clare aa a Tete ae it is very small and is usually overlooked until its injury to the plant upon which the egg was placed becomes severe enough to attract attention. This early period in the growth of the larva is practically the only time when it may be destroyed by the use of poisons. The period of growth of the larva is largely depend- ent upon temperature and the abundance of the food supply. The average lengih of this stage, in the summer months, is about sixteen days. During this short period the larva grows from a tiny object three-fiftieths of an inch in length to a stout worm 1} to 14 inches long. There is a decided variation in the color aud markings of dif- ferent individuals, nearly every gradation occurring from a pale green through rose color and brown to almost black. The pupa.—When the larva has completed its growth it leaves its food plant, usually attempting to reach the ground by crawling; it then selects a suitable spot, usually within 2 feet of the base of the plant from which it crawled or fell, and burrows from 2 to 5 inches into the soil. A cell is then constructed running back to within from one-fourth to one-half an inch of the soil surface. This provision is made so that the moth may easily push off the cap of the cell and escape. When this cell is complete the larva molts its 290 —— sss 2 | ’ skin at the bottom where the burrow is somewhat enlarged, and there enters the pupal or resting stage. The accompanying figure (fig. 2) illustrates the general form of a cell, with the pupa in its normal position. As is the case with the egg and larval stages, the pupal stage is shortest during the summer months, usually lasting from twelve to sixteen days. The insect passes the winter as a pupa. thf, CH iy, LLG SY fag g > “cane SS nie Ss (RES be Soy gence RA Ss j are Fig, 2.—Vertics' section through the soil, showing pupa of bollworm in its burrow. (Copied from Quaintance and Brues.) The fact that the adult is unable to make its escape when the pupa is buried under a few inches of dirt and that the pupa itself is killed by undue exposure immediately suggests the importance of fall and winter plowing so as to destroy these cells and thus expose the pup to the inclemencies of the winter weather and to destruction by birds and other enemies. This phase of the subject will be dis- cussed later within these pages. 29483—No. 290—07 m 2 10 The pupa is nearly four-fifths of an inch long, shining, and of a reddish brown color. The adult.—The bollworm moth, though very readily seen in corn or cotton fields, is recognized by but few planters as the parent of the bollworm. The accompanying figure (fig. 3) may aid in its recognition. The moths vary considerably in color and markings, ranging from a dull olive green to nearly white. Some have conspicuous markings, while with others the markings are almost entirely absent. The body is about three-quarters of an inch long, and the wing expanse is about 12 inches. During daytime the moths are seldom seen flying about, but late in the afternoon they come out from their hiding places among the foliage to seek food and deposit their eggs. It may be remarked here that the adults are capable of tak- ing liquid food only. During the latter part of the summer this con- sists mainly of nectar secreted by the cotton plants. The moths are also very fond of the nectar secreted by cowpeas and when the latter are present the moths will leave the cotton fields to gather food from this source. It was found, from a large series of ex- periments conducted by Mr. A. A. Girault during the investigations Fic. 3.—Bollworm moth in natural position, of 1904, that the lengt h of life of wings folded. About twice natural size(from the moths depends largely upon esos): the food supply. This also greatly influences the number of eggs deposited. In the experiments re- ferred to above, where no food whatever was given the moths the average length of life was five and one-*ourth days, and where sirup was given each day it was twenty-three and two-thirds days. Length of life cycle—The life cycle, from the deposition of the egg to the emergence of the moth, is completed in about thirty days during the summer months. FOOD PLANTS. The bollworm is practically omnivorous. Its habit of very general feeding is among the difficulties experienced in attempting its control. The plants upon which the larve have been known to feed number about 70. The principal crops in the United States depredated upon 290 et by this species are cotton, corn, tomatoes, tobacco, and various garden crops. Various names have been applied to this insect according to the food plant or character of injury inflicted, the names “ bud worm,” “ corn-ear worm,” “ tomato fruit-worm,” etc., being variously applied. The term “sharpshooter,” being very loosely used, is quite often applied to it. The exclusive use of the term “ bollworm ” should be encouraged to prevent confusion, regardless of the food plant upon which the insect is found. SEASONAL HISTORY. As has been stated, the winter is passed in the pupal stage in cells formed in the ground for that purpose. In the spring the moths emerge at a time varying considerably in different individuals and latitudes. In southern Texas, in the latitude of Victoria, the majority of the adults emerge early in April, and in northern Texas, in the lati- tude of Paris, about the middle of May. At Dallas, Tex., the date of the main emergence seems to be but little earlier than at Paris. Of course the time of the first as well as the maximum appearance of bollworm moths of the first generation depends largely upon the spring temperatures. Soon after emergence in the spring the moths fly about to find suitable places for egg deposition, the great majority of them ovi- positing upon the leayes of the young field corn, which is usually about 1 or 2 feet high at this time. Upon hatching, the young larve feed on the corn leaves, usually eating into the roll of tender leaves at the growing tip. This produces the characteristic shot-holed appear- ance in the leaves as they unfold. By the time the second generation of moths appears, the corn is coming into silk and tassel and the eggs are deposited in numbers on the silks and tassels, as well as upon the leaves. This is the most destructive generation upon corn, the ears being largely attacked. The larve of this generation pupate about the time the ears begin to harden, so that when the moths of the third generation appear, about two weeks later, the corn ears are nearly all hard and consequently unfit for food for the young larve of the ensuing brood. Finding the corn hard and dry the moths are attracted to adjacent cotton fields, where most of the eggs are deposited; from these issues the destruc- tive August generation of larve, which is the main source of injury to the cotton crop. Corn is by far the most preferred food of boll- worms, hence if they can find late corn in the neighborhood the moths oviposit upon it rather than upon cotton. Injury from the fourth generation is rarely serious, as the numbers of this generation are greatly reduced by parasites and unfavorable 290 12 weather conditions. The larve of this brood are often quite nu- merous on alfalfa and in a few instances do serious damage to very late cotton and corn. The larve of this generation usually form somewhat deeper cells than those occurring earlier -in the season and for the most part they pass the winter as pupe. However, a few moths may emerge, giving rise to the larve found in very late corn and gardens up to the time of heavy frosts. The number of annual generations varies in the cotton belt from four to six according to the latitude.. EXTENT OF INJURY. Severe injury to cotton is confined largely to the western portion of the cotton belt. During the past few years Texas has suffered by far the greatest loss of any State from bollworm ravages. Yet the losses due to bollworm depredations in Louisiana, Indian Territory, Okla- homa, Mississippi, and Arkansas are by no means small. A combination of circumstances in the western portion of the cotton-growing area has resulted in theoretically almost perfect con- ditions for bollworm development. The great increase in the cotton acreage during the past few years has been due largely to the develop- ment of lands west of the Mississippi on account of the westward tide of immigration. Central and northern Texas have afforded a vast practically unbroken area of cotton and the people in general have looked upon cotton and corn as the only crops to be successfully grown on a large scale. Hence the valuable practice of crop rotation has been sadly neglected. Insufficient cultivation, due in part to the tenant system so generally employed upon the large plantations in Texas, and to the planting of an acreage of cotton too great for the working force, and also the continued planting of run-down seed without regard to earliness, prolificacy, or quality of staple, have each lent their unfortunate influence in increasing the seriousness of the boll- worm problem. The average annual injury by the bollworm to the cotton crop of the United States is probably in the neighborhood of $12,000,000. INJURY, 1903-1906. As has been pointed out, the extent of injury to cotton varies greatly from year to year. From a study of conditions during the © past few years it appears that this depends mainly upon the relative earliness of the cotton crop, together with weather conditions. The amount of plowing done during the preceding fall and winter also exerts a decided influence upon the extent of injury. During 1903 the cotton crop was exceptionally late; owing to adverse weather conditions during the preceding fall and winter 290 13 practically no plowing was done; the weather conditions during the latter part of the summer were favorable for bollworm increase; as a result, a year of severe and widespread depredations was experi- enced. Conditions in 1904 were almost the reverse and injury was much less general and less severe. The crop was planted very early, this being due in part to the fact that weather conditions during the fall and winter of 1903 permitted general plowing and preparations for planting. The winter plowing evidently resulted in the destruc- tion of many pupe, so that the moths emerging in the spring, as well as subsequent broods, were greatly lessened. On account of the decided earliness of the crop a considerable number of bolls were sufficiently mature to escape injury in the presence of an abundance of young bolls and squares. During 1905 conditions were again favorable for bollworm depre- dations, and quite heavy losses were experienced in many counties in Texas, Indian Territory, and Louisiana. For some unknown reason little preparation was made in the fall of 1904 for planting during the following spring. The severe weather in February, followed by a wet spring, especially in northern Texas and Louisiana, resulted in general late planting throughout that section. Many heavy rains in the early summer, especially in northeastern Texas and western Louisiana, resulted in the very poor cultivation of most crops, and the complete abandonment of many fields. While severe bollworm injury to cotton occurred over a considera- ble area of Texas and Indian Territory during the season of 1906, the total loss due to the pest was not so great as that inflicted in 1905. Contrary to usual conditions the counties of extreme northeastern Texas did not suffer severe injury. The area of greatest damage extended throughout the two northern tiers of counties of Texas, from Lamar and Delta to Clay and Jack counties, and included the southwestern portion of Chickasaw Nation and the southern part of Choctaw Nation, Indian Territory. The loss to cotton growers in this area varied from 10 to 65 per cent of the crop, and in certain late-planted tracts the destruction of the crop was so complete as to render it unprofitable to even pick over the fields. The precipitation in this section during July and August was con- siderably greater than normal and this condition was undoubtedly accountable, in part at least, for the greater loss occasioned by the bollworm. In the following table a comparison is made of the cotton crop for each of the years 1903 to 1906, inclusive, in those eight counties of Texas in which exceptionally severe bollworm injury was inflicted during the year 1906. The annual crop is given for these eight counties, taken collectively, 290 14 as also its percentage of the total crop of Texas for each year. The figures used in all cases are the number of bales ginned to December 13 of each year as given by the Census Bureau. TasLe I.— Comparison of the cotton crop of eight counties in Texas for the years 1908-1906. Number of | Number of | Number of | Number of bales, 1906. | bales, 1905. | bales, 1904. | bales, 1903. Bere eer nae tne > Seber pee = eee ele eee 85, 128 55, Speen nikisicie nate Sasme is aisiamcin eaip ais sbeenicm enema ee eee 28, 048 17, 887 Sees e he aiind- «st. see oap ee eenie eee eased sees 6, 456 31, 778 SC DO e ae R ee See Ue een ea Ree Sac 81, 031 40,314 Gata dees sina ee oo Ds «es ee eee ee eens 81, 878 48,770 es OMSEe ale nina Misia cieminne aise ae mesos mele els Seteee ee RRS 45,4 BE ede sees Soe See ELee sass Seew eeoaeeeisee 36, 270 27,370 Bae meeaiaiese vishi= a Date of examina-| S| 4 am es t= tale tion. oa oS a 3 aa] 3 & | Se) e g 2 a) = ton a a = tH aS z oe] a ce 3 PA Mi o PP oh b ost die |e Beles. 2 = 3 igen = = lS | ote bb | 218 )2)3) 2 , eles Siete |e =] S] a sf a =| a3 | 6] 2 a | E) A ° ) ° je) ° < 4 ° [o) Se eee 55 Ardmove, Ind, Ji. 520. 504. ad D: Li, King 2a oa ee ee ee 40 i 290 21 During 1905, in addition to the 405 acres mentioned, about 50 acres were used in 12 farms near Clarksville, Tex., in a cooperative test of the corn trap-crop system, and several small areas were used in cooperative work in other localities. Upon these experimental farms an endeavor was made to demon- strate the value of the several remedial measures outlined in the pre- ceding pages, under “ Means of Control.” In all of the experiments conducted in 1905 the results, as shown by final yields, were supplemented by observations throughout the season upon the relative earliness of and comparative bollworm in- jury to the plats receiving various treatments. The results of these observations conform closely with the final yields and strongly em- phasize the value of improved methods in protecting cotton from bollworm injury. These observations include cotton grown on the principal types of soil of northern Texas. At the time of examination the injury to late planted cotton and to cotton raised from degenerate seed varied from 12 to 49 per cent, and to early planted cotton and cotton grown from improved seed the injury varied from 1 to 23 per cent. To illustrate the decided preference of the bollworm for the less mature fruit, of a total of 24,292 squares and bolls examined in sev- eral localities, those one-half grown or less numbered 20,789, of which number 20.4 per cent were injured; the bolls over one-half grown numbered 3,504, with 7.2 per cent injured. The contrast between the percentages of injury would have been still greater had the exami- nations been made two weeks earlier, as a considerable number of the injured squares and bolls had fallen and were buried by cultivation, while the majority of the more mature fruit was retained by the plant even though badly injured. ARDMORE FARM. The experimental area on the farm of Mr. S. A. Brown was located on a typical sandy soil of the cross timber region and consisted of ten 4-acre plats. The experiment consisted of comparing the King and Rowden varieties now becoming so generally adopted in the bollweevil and bollworm districts of Texas with the much later big-boll sorts from gin-run seed. The effect of commercial fertilizers upon the early maturity and toval cotton production was also studied. Three stand- ard commercial fertilizers were used in the experiment: (1) A com- plete fertilizer, showing by analysis 8 per cent available phosphoric acid, 2 per cent potash, and 2 per cent nitrogen; (2) a compound of acid phosphate and potash without nitrogen, the analysis of which showed 10 per cent available phosphoric acid and 4 per cent potash; 290 22 (3) acid phosphate alone, showing by analysis 14 per cent available phosphoric acid. The following table shows the treatment given and the yield from the several plats, together with the increased yield from the use of fertilizers and improved seed, as compared with the yield of cotton from ordinary gin seed. TaBLE III.—Treatment of and results from plats on bollworm experiment farm of U. 8S. Department of Agriculture, Ardmore, Ind. T., 1906. is} n ns be 2 3 EE 3 a | g Fic 5 5 ce an 8 Sle Box a i=] em 2) 4 a8 A= a2 EY = ; Fertilizer, and a}|@ WER 268/23 be 2 a Variety of cotton. quantity used ceegeee q § & ° 32m 338 8 3 . peracre, |Penting. 2 |) s 23 HOS 154 = i SiS] 2 |oge |e | & | o B\/5! & | 880 lsad| = | s aia = gaolosd! 5 a g\a| 3 Bud |258| 3 | 2 5| 2 Ssalgsal 2 | 8 a A al ma > oO a Ti PRN ete a eto we ic Cl B rik 300 | Apr. 28 | 4] 38 1,082.75 | 712.75 |$23. 25 |$3.45 |$20. 07 pounds. NE MEOW GCI eer = <2 sete | aie Ue Bas ace Apr. 29} 4) 3 | 1,003.75 | 683.75 | 20.91 | 3.45 | 17.46 2 A NG Gt 0 | oe Unfertilized -.. ner | i: Se i} 810.75 | 440.76 | 14.54 |...... 14. 54 IV | Rowden............. Bees Hag 300 WerssOOwe. | Aale:3 837.50 | 467.60 | 15.42 | 3.23 | 12.19 pounds JAE Wis bo chee RR eee eee [an ear (a ers May 2 NES] 834.50 | 464.50 | 15.33 | 3.28 | 12.10 VII Big boll eas Unfertilized...| May 3] 4] 8 370:00 | co asede et Semel s eee eee nown). VOLT KTS Se ote ee one RA. PE. E. ,° 800| May 4] 4] 3 917.00 | 547.00 | 18.05 } 2.85 | 15.20 poun 3. ER ROWGen-. so ccn ce uafertilized wines do Ais 430.25 | 60.25] 1.99 ]...... 1.99 >.< oo GQ. dpe es cee Re SA. a 300 | May 5] 4] 38 749.75 | 379.75 | 12.53 | 2.85} 9.68 | pounds. aC. B. G.—A commercial cotton boll guano; analysis—available phosphoric acid, 8 per cent; peed, 2 per cent; nitrogen, 2 per cent. dR, P. C.—A commercial potash compound; analysis—available phosphoric acid, 10 per cent; potash, 4 per cent. cR, A. P.—A commercial phosphoric acid; analysis—available phosphoric acid, 14 per cent. Table IV, which follows, shows the comparative earliness of fruit maturity on the several plats. The amount of seed cotton picked from each plat during each month is followed by the total amount picked from said plat to the end of that month. TABLE 1V.—Comparative earliness of fruit maturity on plats on bollworm experi- ment farm of U. S. Department of Agriculture at Ardmore, Ind. T., 1905. Total pounds of seed cotton picket, Plat : During . During To No- During | To De- No. | , During ToSeptem-| During | To Octo- & 2 August. ee ber 30. October. | ber 31. No pbc : a Decoy combes I 613 1, 834 2, 447 1, 223 3, 670 661 4, 331 0 4, 331 II 568 622 1,190 1, 021 2,211 1, 502 3,718 300 4,013 Ill 247 1, 086 1,333 678 2,011 952 2, 963 280 3, 243 IV 0 916 916 821 1, 737 1, 303 3,040 310 3,350 Vv 565 1, 358 1, 923 |. 821 2,744 274 3,018 320 3, 338 VIL 0 302 302 0 302 0 302 1,178 1, 480 VIIL 191 1,127 1, 318 1, 329 2,647 0 2,647 1,021 3, 668 IX 0 303 303 533 836 0 836 885 1,721 x 0 786 786 655 1, 441 836 227: 722 2,999 290 23° From a study of the table several important points immediately present themselves. The decided earliness of fruit production upon the King plats is very noticeable. During August all of the King plats had opened a sufficient number of bolls to be picked over, while but one of the Rowden plats could be picked. The uniform earli- ness of the fertilized as compared with the unfertilized plats is also noticeable; for instance, on September 30 Plat I—King seed, fertil- ized—had produced 2,447 pounds seed cotton, while on the same date Plat I1I—King seed, unfertilized—had produced but 1,333 pounds. ‘Comparing results from the use of the three different fertilizers, plats upon which the complete fertilizer was applied excelled both in earliness and total production. 'The average yield per acre in pounds of seed cotton was 1,043.25, 836, and 833.37 upon the plats fertilized with complete fertilizer, potash compound, and acid phosphate, re- spectively. The contrast in earliness and total yield in the case of Plat VIII, planted with unimproved seed and unfertilized, and the various other plats is so marked as to need no special mention. NEW BOSTON FARMS. Twelve plats of 4 acres each were used in the experiment. con- ducted upon the plantation of Mr. H. B. Eubank during 1905. The soil upon which the experimental farm was located consists of a sandy loam, with a red clay admixture. The exceedingly adverse weather conditions during the spring and early summer greatly handicapped the experiment, and resulted in a smaller yield than was anticipated ; however, all circumstances con- sidered, the results were very satisfactory. The experiment consisted of a fertilizer test in a King, Rowden, and gin seed were used. The best results, both in earliness and total raguetion, were obtained by using King seed, fertilized with 300 pounds of cotton-seed meal and 100 pounds of acid phos- phate per acre. Almost as good returns were secured by using King seed fertilized with 100 pounds per acre of each of the following: Acid phosphate, German kainit, and nitrate of soda. During the past season Mr. J. N. Glass conducted a similar experi- ment upon his plantation, which is located in the deep sandy land region south of New Boston. Owing to the comparative freedom from bollworm injury the cultural methods employed were not put to a severe test, hence the results as shown by the total yield from plats where fertilizers and improved seed were used and early plant- ing and thorough cultivation were practiced can not be satisfactorily compared with the yields from unfertilized plats planted to gin seed 290 24 and receiving only ordinary care. In all cases there was a ready response to the application of complete fertilizers, both in earliness and increased production. SUMMARY REMARKS CONCERNING THE USE OF FERTILIZERS. From three or even several years of tests with fertilizers the writ- ers would be entirely unwarranted in making other than certain general statements regarding their use. The decided variability in the soil constituents, even upon the same character of land, and the variation in weather conditions during different seasons render specific recommendations inadvisable. Many of the Texas soils have been found to be benefited by phos- phoric acid. As the chief object of these experiments has been to increase early fruit production, and as acid phosphate influences and hastens fruiting, the general plan has been to supply an abundance of this element along with the other elements in which the various soils are supposed to be deficient. The question is still open as to whether the general use of fertilizers upon the rich bottom lands and strong, black waxy lands of northern Texas will prove of value. However, there seems to be no doubt that the application of fertilizing elements to many of the soils of northern Texas and Indian Territory will increase the earliness and prolificacy of cotton. The experiments at Ardmore, Ind. T., and . New Boston, Tex., indicate that the use of complete fertilizers with a large percentage of phosphoric acid will give best results upon the. sandy loam soils of those types. Experiments conducted upon the gray or mixed soils, as in the case of the plats on the farms of Mr. C. E. Keithly at Wolfe City, Tex., and Mr. S. W. Kanady at Denton, Tex., indicate that soils of this type respond freely to the application of acid phosphate. The addition of a small percentage of potash to an acid phosphate fertilizer seems also to give beneficial results. In general, fertilizers containing large percentages of nitrogen should be avoided, as they tend to produce a large and succulent growth of stalk and foliage which favors bollworm as well as bollweevil depredations. In order to secure the best results from the use of fertilizers it is necessary that the soil be kept in Eee physical condition. It is to be hoped that the data obtained during the investigations of the past three years may serve as a basis for experimentation on the part of planters in various localities to determine which of the three principal elements of plant food—namely, phosphoric acid, potash, and nitrogen—and what proportions and: amounts of each, will give the best results on their respective soils. 290 29 INJURY TO FIELD CORN. The close relation between the depredations of the bollworm upon corn and cotton has necessitated a careful study of the insect in the former as well as in the latter crop. The characteristic injury to corn has been described in the preceding pages. Although bollworm injury to cotton greatly eclipses that to corn, the loss occasioned by its presence each year in probably more than 75 per cent of the corn ears and by the additional damage resulting from ferments, molds, and rain admitted through the exit holes of the larve is considerable. Injury to young corn by the first brood of bollworms is seldom serious. A notable exception, however, is presented in the case of extremely severe injury inflicted upon young corn by this brood at Victoria, Tex., during the spring of 1905. Mr. W. W. Yothers, of the Bureau of Entomology, investigated this outbreak quite thor- oughly during the latter part of May. It was found that severe injury had been inflicted over quite an extended area, necessitating the replanting of a considerable portion of the corn acreage to June corn or cotton. It was estimated by Mr. Yothers and others that the total yield in the vicinity of Victoria would be reduced fully 40 per cent on account of bollworm injury. Severe injury to corn was re- ported also in Shackleford County, Tex., but its extent was not definitely ascertained. ! In 1905 numerous observations in northern Texas and Indian Ter- ritory showed the number of eggs and larve to be comparatively few upon corn until about July 1. After this date, however, from 90 to 100 per cent of the corn ears were found to be infested. No serious injury to corn was reported in 1906, but observations showed that practically complete infestation of corn ears was attained during the latter part of the summer. The chief means of reducing bollworm injury to corn is by thor- oughly breaking, during the fall and winter, all land likely to contain hibernating pup, a procedure which the writers have stated to be an important part of the cultural system in reducing bollworm injury to cotton. The practice of having children and plow hands destroy all larvee noticed in the buds of young corn plants is commendable. ~~ RESULTS OF POISON EXPERIMENTS. During 1904 poison experiments were conducted at Ladonia, Paris, and Cooper, Tex. At Ladonia and Paris the experiments were con- ducted directly by the writers, while at Cooper the work was carried out by Mr. N. P. Robertson, of that place. The dusting method was used exclusively. The Paris green was mixed with fine, air-slaked lime at the rate of 1 pound of Paris green to 4 pounds of lime, and the 290 26 mixture applied at the rate of 15 pounds per acre. The general plan adopted in all the poison experiments was to select two areas of from 3 to 10 acres each upon which the cotton was as uniform as possible, then to apply poison to one, leaving the other as a check. _ At Ladonia and Paris 24 acres were poisoned, an equal acreage being left unpoisoned as a check. A hand blower, mounted on a wagon with wheels sufficiently far apart to include between them two cotton rows, was used in these experiments, while at Cooper a geared blower was employed. Desirable results have attended the applica- tion of poison in practically every instance. The unfavorable results shown in a few cases were attributable to unevenness of stand or to a too late application of the poison. The results of the poison experiments at Cooper are given below: TaBLE V.—Results of experiments of the U. 8. Department of Agriculture in poisoning the bollworm, at Cooper, Tex. : ' od faa Ye c bo © Z | 318 |8 |e 1B 18 |Sal8 & = 4 a ee S i) Koja. E Tf Sob 18s [2.1 Ss) ee oe AS, ~o ea E2 eo ier 2 Zs Is g = Ko} 2 ~ 0S a oo | & e & : cs = a4 Soot ee as B | Ceol ae On plantation of— | 3 3 2 i} ge c a Ze 22 ES £5 RE Dal = = 2 a) to en | ee St 2 8 | $8 | 82 |8a0g| 28 | 28] Se! os 5 rs 8 5 ie Ol aeek (er Oe e Vs | "sa 3S a 5 on, OR | Cot] g A. A, ae) 8 5 3 & se el ees yaar ay ES ne = s g = 2 2 ‘gaa | 3 = 2a | 4 = < < mn nm o = oO Oo [4 ——} = ia Le a | Acres. | Acres. Lbs. Lbs. Lbs. | §. Robertson ........ 1] Aug. 15 23 21| 2,508 | 1,892 | 246.5 | $8.00 |$0.61 |$0. 60 | $6.79 "TPG Titer test: 5 ack 1| Aug. 9 53 53] 6,325 | 5,750] 100.0] 3.25] 0.61 | 0.60| 2.04 Fred Johnson ....... 1| Aug. 11 5 5 | 3,954] 3,546] 81.6] 2.65] 0.61] 0.60] 1.44 N. P. Robertson ..... 2 ree a i 5 5i| 5,922 | 38,609 |. 420.0 | 13.66 | 1.22 | 1.20 | 11.24 The above figures show a weighted net gain of $5.21 per acre upon the four poisoned areas, as compared with similar adjoining areas which were not poisoned. The marked gain upon the plat receiving two applications was probably not due so much to its having received two applications as to the exceptionally favorable conditions attending the poisoning. The two fields showing the greatest gain per acre were smooth, so as to admit of the easy manipulation of the large machine over the entire area, while the others were more or less rough; the wind was also favorable when the former fields were treated. A slight shower preceded the second application upon the area on Mr. N. P. Robertson’s farm, thus causing the poison to adhere well to the plants. During 1905, at Quinlan, Tex., about 50 acres were used in poison experiments. In general, the results of these experiments were satis- factory. Apparently no advantage was gained by making a second 290 27 application between August 17 and 20, the first having been made between August 1 and 5 On August 24 counts were made to determine the percentage of injury to cotton on the poisoned and unpoisoned areas on the farms of Messrs. W. A. Wallace and W. Higden. Ten typical plants were chosen in each of the poisoned and unpoisoned areas, and all fruit upon the plantssand ground beneath them carefully examined. On Mr. Wallace’s farm the plants on the unpoisoned plat showed that over 16 per cent of the entire fruit was injured, while only 10 per cent of fruit on plants on the poisoned plat showed injury. On Mr. Higden’s farm 15 per cent of the fruit of the plants on the unpoi- soned plat was found to be injured, while but 9 per cent was inj on the poisoned plat. TRAP CROP EXPERIMENTS. In view of the fact that the greatest benefit from the use of June corn as a trap crop will come from its general planting throughout a neighborhood, an endeavor was made during the spring of 1905 to arouse general interest in the trap-crop system among the farmers in the vicinity of Clarksville, Tex. Nearly every season bollworms are more or less destructive in this locality, hence it was deemed a desirable place for a test of this kind. Arrangements were made with each of several planters just north of Clarksville to plant from 3 to 6 acres of June corn and cowpeas. The total area thus arranged for in the experiment was about 50 acres. Unfortunately the abnormally heavy rains during June and early July rendered cultivation of the corn impossible. In several in- stances the crop was entirely killed out by the excessive rains and weed growth. There is no way of measuring the value of a trap crop in pounds of seed cotton, as it is impossible to arrange a check plat of cotton where conditions are identical without having the plats adjacent, and in this case equal protection is afforded both of the cotton areas. Although the experiment was greatly handicapped by the above-men- tioned weather conditions, numerous observations during August and September showed that the adjacent cotton was being protected to a considerable extent by the deposition of a large number of boll- worm eggs on the trap corn. At Quinlan, Tex., about 30 acres were utilized in a similar experi- ment, with apparently good results. In some instances, in addition to the protection afforded the adjacent cotton, a large yield of corn was obtained from the trap areas. 290 ~ ~ 28 LOCAL EXTERMINATION. Many insects increase with amazing rapidity from the compara- tively few individuals which pass the winter successfully to the countless thousands at the close of summer. The bollworm offers a good example of this, although the increase in its case is not so strik- ing as with some other insects. It has been estimated by Messrs. Quaintance and Brues, from observations made during 1904, that in the third generation the larvee resulting from one female emerging the previous spring would number 21,175; or one larva of the first generation will give rise to 683 descendants in August—a sufficient number to completely ruin 78 large cotton plants. In making these calculations due allowance was made for destruction in the different stages by various natural agencies. From these figures the importance of destroying the larvee of the early generations is very apparent. Experiments conducted at Quinlan, Tex., and Atoka, Ind. T., dur- ing 1905 indicate that in isolated localities almost complete freedom from bollworms in cotton may be secured by destroying: the larvee of the first and second generations in all adjacent cornfields. Various mechanical devices have been suggested for use in de- stroying larve in corn ears. The writers have given the subject some attention, but have been unable to devise any satisfactory scheme for killing the larve without opening the ears by hand. When mechanical devices are used the ears are often greatly damaged and in many instances the larve escape. In the experiments conducted very few larve of the first generation were seen in the young corn, and the fields were not carefully gone over at that time; however, nearly every ear was infested by the second brood, as is shown in the accompanying table. In case of the Mineola record, ears upon which eggs were deposited were not included in the number of those infested. Had these been included with the number of infested ears, as should ‘have been done, the infestation would have reached about 92 per cent. TABLE VI.—Bollworm larve in corn and cost of extermination. Cost per Date of ex- | Total ears |” pS petrol Total larve| acre of ex- termination. | examined. destroyed.| termina- fested. taael Locality. ; a a la hs se Quauilan’ Tew 25 225.5426 se es July 25,1905 8, 615 96 8, 706 $4. 1 40 sad dma c. Seoceo ae ed ee July 29; 1905 8,279 95.7 10, 924 3.54 Mividol Tam 225. oc. 2ik-coee aun oldede July 20,1906 14,748 74.4 11, 039 2.20 At Quinlan the larve were extracted from the ears on about 3 acres of corn and at Atoka from about 23 acres. About 73 acres of 290 29 corn were thus treated at Mineola. The stand, however, was poor, and therefore the number of ears per acre was comparatively small. in these experiments each ear was opened sufficiently at the tip to _ admit of the destruction of all larve with the fingers. The cost of the work was increased about one-third on account of the making of a complete record of the number of eggs upon the fresh silks wih the number and approximate size of all larve. For several reasons it is safe to say that the practice of destroy- ing larve of the early generations in corn, however important, will never be generally adopted. In the first place it would be impossible to get concerted action in work of this kind, where immediate results can not be seen. The question of securing efficient labor at the time the work should be done, though difficult, would be no more so than that of finding time to go over large areas of corn. The practice of opening the corn ears might also be objectionable in some cases, as it would increase the danger of loss from decay and mildew during rainy seasons. The husks should be closed after removing the larvee, so as to protect the ears from injury by birds. At present it seems th&t the plan of extermination can only be profitably adopted in isolated localities and where the corn acreage is small as compared with the acreage of cotton thus protected. Owing to the fact that the moths fly freely, entire protection to cot- ton can not be insured even though all larve are destroyed in adjoin- ing cornfields—if there are such in the immediate neighborhood. However, where some barrier exists, such as timber or a large field of -grain—the former especially—between neighboring cornfields and the area for which protection is being sought, there is little danger that moths will find their way in numbers to the cotton. \ THE MORE IMPORTANT NATURAL FACTORS IN BOLLWORM CONTROL. The feeding habits of the bollworm larve afford them much pro- tection from various natural enemies. The mortality from these sources is therefore much greater in the egg stage than during any other period of development. Numerous parasitic and predaceous insects destroy a great many eggs and this is especially true where the egos are concentrated upon certain plants, as in the case of corn used asatrap crop. A tiny parasite, scarcely visible to the unaided eye, is responsible for the destruction of from 20 to 80 per cent of the eggs laid upon corn, as well as a large percentage of those upon cotton. Numerous insects feed largely upon bollworm eggs and small larve; the larvee of several ladybirds and small larve known as aphis lons are among those most beneficial in this respect. 290 30 The larger bollworm larve are preyed upon by several insects, among the more important of which are several species of wasps and ground beetles. The value of the common black and red wasps which so frequently build nests in trees and outhouses near cotton fields is unquestionable. At Paris, Tex., during 1905, a nest of the former species, located in an old cotton house with several cotton fields near by, was carefully observed for two hours. The nest con- sisted of about 800 cells, with about 280 adults present -at one time. During the period of examination 168 wasps entered with food for their larve and for other adults. In 118 instances the food brought in was recognized as being bollworm larve. Probably the majority of the other 50 wasps carried bollworms, but identification was impos- sible, because the larve were so badly mangled. Several large robber flies, so often seen in cotton fields, and a few species of spiders, have been known to capture bollworm moths. The common toad also is beneficial, for in several instances the writers and others have found numerous bollworm larve in its stomach. ; . There are published few records of bird’ feeding upon bollworms, yet there is every reason to believe that bollworm larve and adults are destroyed by many species. Domestic fowls are undoubtedly valuable in reducing the number of bollworms on cotton located near houses and barns. Several instances have come under - the writers’ observation in which cotton adjacent to barns where chickens, turkeys, and guineas were kept was practically free from bollworms, _while at some distance out in the fields the injury was quite severe. One of the most important checks upon bollworm increase is the cannibalistic habit of the larvee themselves. After the larvee have attained considerable size they are ever ready to engage in battle with their fellows whenever they chance to meet. When two larve are of unequal size the smaller is usually killed and devoured by its fellow, but if their size is about the same, both larve often die as a result of injuries inflicted upon each other. This factor is of greatest importance in corn, for if all of the larve hatching in the silks of an ear should attain full growth nearly every ear would be completely de- stroyed. The reduction in bollworm numbers in ears of corn, due mainly to this cause, is illustrated by the following figures: During August, 1905, 10 ears of corn were examined just after the silks began dying, and 198 larve in all stages of development were found. This gives an average of 20 larve per ear, most of which were small, or about 10 times the number which would ultimately reach ma- turity. Cannibalism is a less important factor among larve on cot- ton, as in that case the larve are more generally distributed over the plants and therefore meet less frequently. 290 31 es A certain bacterial disease is worthy of note as an important natu- ral factor in bollworm control. As a rule the disease develops among the larger larve and a larger percentage of larve usually die in corn ears than upon cotton; this is probably due to the fact that more moisture is present in the corn ears than in the small fruit of cotton where the larve feed. From 2 to 50 per cent of larve taken on corn and cotton and kept in the laboratory have been found to die of this disease. Examination of several thousand ears of corn during July showed that from 1 to 5 per cent of the larve found therein had suc- cumbed to this disease. RECOMMENDATIONS. The investigations conducted by the Bureau of Entomology during the past three years show that by the general adoption of the several means of control herein described losses from the bollworm may be largely prevented, even during years of severe injury. The fact that bollworms do not become numerous in cotton until the- hardening of the early corn about August 1 is the basis for the recommendation of certain cultural methods not only advantageous in the presence of the bollworm and boll weevil, but desirable prac- tices in cotton growing regardless of insect enemies. These methods are as follows: (1) Thorough plowing of the land during the fall and winter. This operation is not only the means of destroying many bollworm pup, but is of importance from an agricultural standpoint, in ex- posing the soil to the actions of rain and frost, thus helping to break up its constituents and render them more readily dissolved and consequently available for plant food. Fall plowing is also a requi- site for early planting. (2) The use of early fruiting varieties of cotton. (3) The use of fertilizers to hasten and increase fruit production. (4) Planting the crop as early in the spring as practicable. (5) Early and frequent chopping and cultivations. Along with the improved farm practices above outlined, the cotton crop may be materially protected by the use of corn and cowpeas as a trap crop (as described on pages 18-19). That the greatest benefit may be derived from the use of the trap crop system it is urged that each farmer in a neighborhood plant at least a few acres of June corn and cowpeas about the Ist of June. The use of arsenical poisons upon the cotton will be found of value in proportion to the severity of bollworm attack. Paris green is recommended at the rate of about 3 pounds per acre, applied in the dust form, either pure or diluted with lime or flour. Application by 290 . if ceo : - 32 er Te e : ee either the bag and pole method or by geared machinery is satisfactory a The work should be done when the plants are moist with dew or after .2 light shower. Two applications, when not followed immediately by rains, should be sufficient; the first should be made when the eggs begin to hatch in numbers, usually between J uly 25 and August 5; this may be followed by a second in about one week. If rains follow the applications, these should be repeated immediately. Destruction of the early generations of bollworm larve in ¢orn seems impracticable, except in certain cases of isolated areas and where the acreage of corn is small as compared with that of cotton. | Owing to the great value of wasps in destroying bollworm larve throughout the season a protest should be made against the common practice of destroying their nests. Where domestic fowls are reared these should be encouraged to feed as much as possible in adjoining cotton. For practical as well as other reasons wild birds should be protected and encouraged in their visits to cotton fields. 290 7 | O - . be oh ea oe" fe “Ae ) -. F a ie ¥ v ' ‘ . 1 A 3 9088 01270 4680