Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices V U. S. DEPARTMENT OF AGRICULTURE. DIVISION OF ENTOMOLOGY— BULLETIN NO. 41. L. O. HOWARD, Entomologist. ^^ W^ , y THE eODLING MOTH. PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST C. B. SIMPSON, Special Field Agent. WASHINGTON: GOVERNMENT PRINTING OFFICE, 1903. .41, New Series, Div.of Entomology, U.S. Debtof Agriculture. Tfm doOedjoarta ofthcAzistral Zones east ofihe. Gre^tiJPUtzks inMcaie- the c^kXctU or^u- ?tuirti£bazvisioTLSof't7ie.seZonjis.knj3^\n i tivc{r (Ls the ATZeffhoJii^JV.Carolirdarv and Arza troripa7%a7i.Faurias. T?icundjoaeApaj't'^ aftlu: Corrected Lo December LIFE ZONES OF THE UNITED STATES C. HART MERRIAM Bui. 4-1, New Series, Div.of Entomology, U.S. De PLATE U. S. DEPARTMENT OF AGRICULTURE. DIVISION OF ENTOMOLOGY— BULLETIN NO. 41. L. O. HOWARD, Entomoloeist. THE CODLING MOTH PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST O. B. SIMPSOTS^, Special Field Agent. WASHINGTON : GOVERNMEXT PKINTINCJ OFFICE. 1 i) 0 ;^ . J)IV1.SI()X OF EXTOMOLOGY. L. O. HowAKJ), EnUjinologiHt. C. L. Marlatt, ill clitiri/e of expernnenkd field irork. F. H. Chittenden, in cJiarge of breeding experiments. A. D. Hopkins, in charge of forest insect investigdtions. Frank Benton, in charge of (ipiculture. W. D. Hunter, in charge of cotton-boll weevil investigations^. D. W. Coquillett, Th. Pergande, Nathan Banks, Asdstant Entoniologists. E. A. ScHWARz, E. S. G. Titus, Investigators. Miss H. A. Kelly, Special agent in silk investigations. R. S. Clifton, F. C. Pratt, August Busck, Otto Heidemann, A. N. Caudell, J. Kotinsky, H. (t. Barber, Assutants. W. E. Hinds, W. F. Fiske, A. L. Quaintance, G. H. Harris, H. E. Burke, A. W. Morrill, Temporary field agents. LETTHK OF TRAXSMITTAI.. U. S. Department of A(;kicui.ture, Division of Entomology. Wash'nuiton, I). C, Jxhj 20, 100 J. Sik: I transmit herewith the manuscript of a report on the codling moth, prepared under my direction hv Mr. C. B. Simpson. Held agent of this Division. Mr. Simpson had l)een charged with a special inves- tigation of the codling moth, more particularly in the Northwest, in answer to special requests for such study in the newly developing fruit interests of that region. The codling moth is undoubtedly the most important insect pest of apple and pear, and is the occasion of greater loss than all the other insect enemies of these fruits com- bined, entailing an annual shrinkage of values exceeding !^11.o()ojm.m». Mr. Simpson's investigations covered a period exceeding two years, and have already been voiced in a small preliminary bulletin and in a Farmers* Bulletin giving condensed advice relative to the control of this insect. The present publication is the linal and complete report, elaborating all of the conclusions and results of this special investiga- tion. It will be a very useful document for all workers in api^lied entomology and of decided practical value for the fruit grower. The illustrations which accompany it are essential to the correct understanding of the experiments reported and of the text. I recom- mend that this report be published as Bulletin No. -tl of the Division of Entonrjlogy. As stated in the lett?r of transmittal of ))ulletin Xo. 40. the term "New Series" has been dropped. Kespectfully, L. O. lIoWAKI), K)i tomoIo(j i'st. Hon. flAMEs Wilson.* fScrrrff/r// <>f A(//'icalturc. C 0 X T 1: X T S . Page. Introduction 9 Systematic position 10 Names of the insect 11 Popular names 11 Scientific names 11 Varieties of the codling moth II Geographical distribution 13 Relation of distribution to life zones 14 Boreal zone 14 Transition zone 14 Upper Austral zone 15 Lower Austral zone 15 Immune regions 16 Means of spread 16 Estimated losses 17 Food habits _ 18 Fruits infested 18 Nut-feeding hal )its 19 Leaf-feeding habits 19 Primitive food habits 21 AVork of other insects 21 Life history 24 The egg , 24 Places where laid 25 When [He eggs are laid 26 The number of eggs laid by one female 26 The egg-laying period 27 Duration of <^'^^ stage . 27 Hatching of the egg 2S Changes during incubation 28 Methods of obtaining eggs 29 Influence of temperature upon the length of the egg stage 29 Mortality among the eggs oO The larval stage ,S0 Description of full-grown Vwwv \\\ Entering the fruit \\\ Places of entrance 82 Time spent in the fruit .S4 Preparations for leaving the fruit \\\ Leaving the fruit \\\ Places of spinning cococ^ns :i5 Description of the cocoon ;^6 6 Life history — Continued. Page. The larval stage — Continued. Duration of the stages in the cocoon 37 Influence of temperature upon the duration of the stage 38 Effect of the insect upon the fruit 39 The pupa 39 Emergence of the moth 39 The adult insect 40 How to distinguish the sexes 40 Habits of the moth 41 Duration of life of the moth 41 Generations of the insect 41 Seasonal history 50 Emergence of the moth 50 Relation between the emergence of the moth and the blooming i)erio(L . . 51 Hibernation 54 Evidences of a third generation 55 Conclusion 56 Natural conditions which tend to decrease numbers 57 Natural enemies 57 Invertebrate enemies 59 How to combat the insect 60 Preventive measures 60 Setting the trees 62 Pruning 63 Irrigation 64 Soil or cover crops 64 Orchard in bearing 64 Preparing fruit for the market 65 Preventive measures in old orchards 67 Treatment of old orchards 68 Remedial measures 69 Measures of little or no value 69 Measures of value 72 Measures used against the larva 72 Materials for spraying 80 Cost of spraying 83 Time and frequency of application of spray 85 How the poison kills the insect 86 The banding system 88 Expense of banding 91 When bands may be used 92 Practical tests 92 Resume and conclusion 96 Bibliography of the more important contril)utions to the literature of the cod- ling moth 97 ILLUSTKATIOXS. PT.ATES. Page Pla pe I. Life zones of the United States Frontispiece. II. Fig. 1. — Api^le leaf inhal)ite2 V. Fig. 1. — Codling moth larva, enlarged about three times. Fig. 2. — The 'Svorm hole" or exit hole of the apple worm (enlarged). Fig. 3. — A wormy apple, showing the familiar mass of brown par- ticles thrown out at the blossom end by the young larva (from Slingerland ) 82 VI. Fig. 1. — Larvae, pupa^ and moths on rough bark. Fig. 2. — Infested apples being ouried 48 VII. Fig. 1. — Codling moth enlarged four times. Fig. 2. — Codling moths enlarged twice. Fig. 3. — Codling moths, natural size 48 VIII. Stubs of branches irom an old orchard near Elkton, ^Id., showing work of codling-moth larvte and woodpeckers (U IX. View in orchard of Hon. Fremont Wood, near Boise, Idaho (54 X. Fig. 1. — Band on which the remains of 330 cocoons were counted. Fig. 2. — Pupa in cocoon on underside of a loose piece of bark. Fig. 3. — Larva and pup;e in cracks in bark from which rough hark has been removed SO XI. Gasoline power spraying machines SO XII. Spraying outfits in use 80 XIII. Clean and wormy apples from tree Xo. 2, Wilson orchard 96 XIV. Clean and wormy apples from tree Xo. 4, Wilst)n orchard 96 XV. CU'au and wormy apples from tree Xo. 6, Wilson orchard 96 XVI. l*re])aringaj)))les for market, orchard of Ibni. Fremont \V(mv1, Boise, Idaho 96 TEXT FKiFUES. Fic. 1. Anarsia lineatella 21 2. IModia interpunctella 22 3. Larverna herellera 22 4. Xej)hopteryx rnbrizonella 23 5. Daily band record made by 11. (i. (iihson, Nampa, Idaho, in \9()\, upon four tn-es 46 6. Weekly summary of Mr. (iihson's hand record 47 7. I'.and record made by William A. (ii-orge. (\Udwell. Idaho, in 1901. 47 S. Weekly band record made hy Mr. Ayres at r.oise, ]«laho, in 1S97. on 1 40 trees 48 8 Page. Fig. 9. Band record made In- Mr. Ayres in 1898 48 10. Band record made l)y David Brothers in Colorado ia ISJu 49 11. Band record published by Prof. C. P. Gillette, taken on 14 trees, at Fort Collins, Colo., in 1900 49 12. Band record taken by Prof. E. A. Popenoe, Manhattan, Kans., in 1890 50 13. Band record made by Chapin on 850 trees in San Jose, Cal 51 14. Band record by Prof. J. M. Aldrich, Juliaetta, Idaho, on 40 trees, 1899 52 15. One of the records made by H. E. Burke, at Boise, Idaho, in 1902, to determine the maximum of the second generation 52 1(1 Record by H. C. Close, Utah Agricultural College 53 17. Spraying outfit for treating tall trees 75 18. Large apple tree properly banded for the codling moth (original) 89 19. Apple tree l^anded, showing bands both above and below a hole in the tree 89 THE CODLING MOTH ( Cdvpocdp^d yoin (nielhi Li ii 1 1 . ) INTRODUCTION. Eveiy person is acquainted Avith ** wormy apples." and man}' have seen the caterpillars in the fruit, while few know the history of the worm-like creature which causes the injury, or whence it comes or whither it goes. If apple insects were classified in the order of the degree and extent to which they cause monetary' loss; the codling moth would rank first, since it causes more injury than all other insect enemies of this fruit combined. It is the most serious drawback with which the apple grower has to contend, as from one-fourth to one-half of the apple crop of the United States is injured every year. The control of this pest, how- ever, is not difficult when compared with that of many other insects, and hosts of apple growers are each year saving practically all of their crop from its ra\'ages. In the literature of the subject^, one finds that C'ato makes the first mention of this insect, and since that time almost every entomologist has studied it and written a])Out it. V>\ the writings of Le Baron, Walsh, Riley, Cook, Gofi", Forbes, Howard, Slingerland, and many others, information a])Out its life history and remedial measures has been disseminated, which have facilitated its control in tin* eastern part of the United States. It was found that in the western United States tlu^ conditions were different from those in the East and that tlie reconnnendations which ])rought success in the East did not give satisfactory results in the West, and the necessity arose of making a close study of thi^ western conditions. Among those who hav(^ \vritt(Mi on the insiH't in the ^^'est are Messrs. Washburn, Koebele, Card, Aldrich. (Jillette. Cordh^y. and Cooley. The two principal accounts of this insect are those by l)r. L. O. Howard in LS8S and Prof. M. \'. SlingiM'land in ISDS. Both of these writings give a summary of what was known of (he instM't at those dates, with many original obsei-\ ations and suggestions for its control. 9 10 Slingerland's bulletin is especially comprehensive, partly because of the late date of its publication, and partly because a complete bibliog- raph}^ and valualile historical notes are given. The excellent observa- tions and photographs are important features of this publication, which has been of the greatest assistance to the writer of this bulletin. The writer is under obligation to many for the aid given in this work. Hon. Edgar Wilson, Hon. Fremont Wood, and Mr. W. F. Cash rendered assistance in carrying out the practical tests; Mr. Alex. McPherson, the State horticultural inspector, made observations and gave aid in many ways; Mr. S. M. Blandford, of the United States W'eather Bureau, at Boise, kindh^ furnished the temperature data used; Mr. H. E. Burke, of the Department of Agriculture, assisted in the work in 190'2, and did much valuable and accurate Vv^ork upon the life hi-story of the insect; Prof. C. P. Gillette and Mr. D. ^\ . Coquillett kindly gave the writer access to their notes. Manv fruit growers in Idaho have rendered especially valuable aid in keeping records. Pro- fessor Slingerland granted permission to use many of his figures, and his bibliograph3% with his notes, is used as a foundation for that por- tion of this bulletin. Prof. J. M.Aldrich, Prof. A. B. Cordley, and Prof. C. V. Piper have at all times given aid, counsel, and advice, and granted permission to use their unpublished data. The estimates of injuries inflicted by the codling moth given in this bulletin are based principally upon observations made upon check trees in spraying experiments. SYSTEMATIC POSITION. The codling moth l^elongs to the order Lepidoptera. or scale-bear- ing insects, and has been assigned to the family Tortricidn?. The description of the genus Ca/'pocajjsa Treitschke, as given b}^ Meyrick, is as follows: Aiitenn?e in $ simple. Palpi moderate, curved, ascending. Thorax smooth. Fore wings with term en slightly sinuate. Hind wings in ^ with longitudinal groove below cell, including a hair pencil; 3 and 4 connate or stalked, 5 nearly parallel to 4, 6 and 7 closely ai:)proximated toward base. A small but rather widely distributed genus. * * * The species lyomonella is distinguished from the other species by having the margin of the ocellus (or black spot on the wing) of a coppery metallic color. (See PL VII.) The description oi pomo7ieUa is given by Meyrick a« follows: 14-19 mm. Forewings dark fuscous, finely irrorated with whitish, with darker stride; basai patch sometimes darker; a large dark coppery brow^n terminal patch hardly reaching costa, anterior edge more blackish, ocellos wathin this edged with bright coppery metallic. Hindwings fuscous, darker terminally. 11 NAMES OF THE INSECT POPULAR NAMES. The name ''codling moth" is the one most generally used bv the American fruit growers. The first name given to this insect was ••pear eater.** on account of its feeding in pears. Later writers called it the ''apple and pear worm or moth,*' ''fruit worm." "fruit moth." and many others names. The name "apple worm*' is often used, especially by the English. Wilkes, an English author, first used the name in ITJrT. which name was taken from a kind of apple tree. Slingerland says that the word •'codling*' is doubtless a corruption of the old English word ''querd- lying.*' which means any immature or half -grown apple. Some hor- ticulturists and entomologists and others use the names "coddling** or "codlin.** As a result of extended research Slingerland discards these names and g-ives the name •'codling'* decided preference. SCIENTIFIC NAMES. In IToS Linnaeus gave this insect the specific name oi pom on ell a and the discription is as follows: "Alis nebulosis postice macula rubra aurea." SchiffermiilierlTTB. named it "pomonana.** Fabricius.1793, gave it the name "pomona.** By reason of the eighteen years priority the name "pomonella" stands. Linna?us gave this insect the generic name of Trnea. Later it was known as Pyrtil'is^ Tortrir^ Semas'ii, and Ennhtea. Still later it was given the name Carpocapm. which was in use for about three-quarters of a century. In 1S9T Walsingham concluded that the name Carpocapm nnist fall and be replaced by Cydia. This view was adopted by Fernald in Dyar's list of North American Lepidoptera: but Cockerell strongly doubted this conclusion. After a very exhaustive study of the sub- ject ^Ir. Busck concludes that the old name Carpocapm is the proper name and must l)e restored, and his conclusions are accepted in this publication. VARIETIES OF CODLING MOTH. Staudinger described a variety of the codling moth which was bred from either apple or walnut in which the coppery spots in the ocellus were more broken and gave it the name ai jmttnrthhina. It has evidently been thought for many years that there was a variety of the codling moth in the far west. Matthew Cooke said in 1883: "From investigation it is probable that there are more than one species of codling moth infesting the fruit of this State [California], but 1 am not prepared to report at tlie present writing." In r.Hio the writer found one butt-colored moth which. exc(^]'>t f(^r color, was like the connnon codliuir moth, on the trunk oi a tret^ at 12 Boise, Idaho. During 1901 four well-preserved specimens and eight badly worn specimens were secured. In 1902 six of these buff-colored moths were bred among 182 normal moths. In material collected in Idaho in the fall of 1902, from which about 30 moths emerged the following spring, five were of this variet3\ Mr. A. F. Hitt, of Weiser, Idaho, and Mr. Alex. McPherson, tell the writer that the}^ have noticed these buff-colored moths. Mr. Hitt, in 1896, bred seven of these among 50 normal moths. The writer submitted the moths to Mr. August Busck, of the United States Department of Agriculture, for determination, and in the Proceedings of the Entomological Societj^of Washington he describes them as follows: These specimens were submitted to the writer for determination, and I have care- fully examinedt hem structurally in comparison with the common form of 0/(7/a(«) pomonella Linne. I do not think there can be any doubt about their being this species; the oral parts, the venation, the secondary male sexual character of the hind wing, and the external sexual organs of both sexes are identically as found in the common dark form of the codHng moth. The general pattern of ornamentation is also the same, but the coloration is so strikingly different that the variety deserves a special name, the more so as no intermediate forms seem to occur. I propose that it be known as Cydia (^) pomonella Linn6, var. simpsonii. Instead of the dark fuscous color of the common form, the variety is light buff, with sUghtly darker buff transverse striation. In the common form the forewings are finely irro rated with white, each scale being slightly white tipped; in simpsonii the scales are not white tipped. The terminal jmtch, which in the common form is dark coppery l)rown, nearly black, and with dark violaceous metallic streaks, is in simpsonii light fawn brown with pure golden metallic streaks. The extreme apical edge before the cilia is in the common form black, in the variety reddish brown, and the cilia in simpsonii are light golden ocherous instead of the dark fuscous of the common form. The head, pali)i, l)ody, legs, and the tuft of hairs on the hind wings of the male are correspondingly light-buff colored in the variety instead of dark fuscous, as in the common form. Besides Mr. Simpson's specimens, in which both sexes are equally represented, there is in the United States National Museum a single-female, labeled ' ' Cook, Cali- fornia, July 30, 1883." Type: No. 6803, United States National Museum. The writer has never observed an}^ gradations between this variety and the common form. It is most probable that this variety is dis- tinctly western, as there are no records of its having been bred in the East. No fittempt was made to secure the earlier stages of the insect, and, as far as observations were made, its life history is similar to that of the normal form of the codling moth, as the larvae from which this variet}^ was bred were taken with the larva? of the normal form under bands on apple trees. One might theorize on what conditions in the West have given rise to this new variety, but to state with any degree «The generic name Cydia used by Mr. Busck before his investigations, which resulted in the restoration of the old name Carpocapsa. 13 of certaint}' exactly what has })r()Uoht ahoiit this chanjic is impossible from the data at himd. GEOGRAPHICAL DISTRIBUTION. The original home of the codling moth is not definitely known, but is supposed to be southeastern Europe, the home of the apple. It has followed the distribution of the apple closel}' until it is now present, with but few exceptions, in all countries where apples are grown. It has spread over Europe, and is present as far as the apple region extends in Siberia. It was noted in Australia about 1855, Tasmania about 1861. New Zealand in 1871, South Africa about 1885. and Zeller received it from Brazil in 1891. Mr. C L. Marlatt reports that he did not observe this insect in either eJapan or China in his extended travels in those regions. Mr. George W. ("ompere also states that he has never observed it in China. Prof. A. B. Cordley states that this insect has reached China. Evi- dently some correspondent of his has reported it as present in that country. As apples are being continualh' shipped to both Japan luid China, it is but a question of a few years when it will either be intro- duced or become injurious in the orchards of those countries. Extended researches of many investigators have failed to give date or detinite information as to the time and manner of introduction of the codling moth into America. For a long time injury to the apple by this insect was thought to be the work of the plum curculio: and it was not till J 819 that the codling moth was reared from wormy apples by Burrell. It was evidently quite well distributed in the eastern United States before its work was identilied, as there are but few records of its spread. In 181M it was a serious pest in New Eng- land and central New York. About 1860 it invaded Iowa. For many 3'ears it has been a serious pest in Canada. Mr. Alexander Craw stated in 1893 that the insect was first introduced into California by means of some fruit l)rought from the East to Sacramento for exhibi- tion purposes in 1S7'2. No measures were taken to destroy the insects in this fruit, and two years later its presence in abundance wus noted. Later it was rapidlv distri))uted over the State, aided by the system of returning boxes. Dr. C. V. Riley mentions in 1876 that this insect was then present in Itah. where it had evidently been introduced a 3'ear or two previously. From these points of infestation the codling moth spread over the Western States. Prof. J. M. Aldrich states that it has been known in the Clearwater Valley in Idaho since 18S7. Mr. I. L. Tiner. of l>oise. states that in 1887 he found the tirst indication of this insect at Boise, Idaho. Mr. Thomas Davis, of Boise, states that it was intro- duced into his orchai-d at about the same time. 14 RELATION OF DISTRIBUTION TO LIFE ZONES. Althouoh the codling moth may be brought into a section o.f countiy, it may not be able to obtain a foothold on account of the adverse cli- mate. In other regions it i.s never ver}^ injurious, or it may be quite injurious one year and almost absent the next; but in warmer regions it reaches the maximum of destructiveness. In order to study these conditions the writer has used the life zones of Dr. C. Hart Merriam (PL I). Upon consulting this map one finds that there are seven different zones in the United States. In • the eastern portion they, in a general way, extend east and west, while in the western part they are broken into irregular areas by the mountain ranges. There are man}^ important subdivisions of these zones, depending principall}^ upon the amount of moisture and the milder and more temperate climate near the seacoasts. BOREAL ZONE. The principal apple-growing regions of this zone are in Nova Scotia, northern Maine, northern Michigan, and western Oi»egon. Except for the Pacific coast strip, only the. more hard}^ varieties of apples are grown in this zone. There is a great lack of definite data in regard to the exact amount of injur}- the insect cauges in this zone. As near as the writer can learn, the injury is never so great as it is in the next warmer zone. According to Cordley, the insect is present in small numbers in the Pacific coast strip and is doing but a comparative!}^ small amount of injury. TRANSITION ZONE. The transition zone includes the greatest apple-producing regions of the United States, the Alleghenian area comprising the zone in the eastern mountain States, including the larger part of the apple-grow- ing regions of New York, Pennsylvania, and Michigan. Although the injuiy, which varies with the seasons, is greater in the transition than in the boreal zone and less than in the austrafl, no record of definite ^percentages has been found during the present «tudy. In the arid area of the transition zone the loss is less than in the Alleghenian area. Various estimates of from 5 to 25 per cent of damage have been given. At Moscow, Idaho, which partakes more of the Pacific coast strip characteristics than of those of the arid area. Professor Aldrich records the amount of injury as 21 per cent for 1899, 10 per cent for 1900, and 5 per cent for 1901. Professor Piper states that in 1898 the average damage about Pullman, Wash., was 10 per cent, and some orchards were injured 25 per cent; in 1902, about 5 per cent. Professor Gillette reports from 35 to 80 per cent at Fort Collins, Colo., varying with the degree of infestation in the localit3^ 15 Cooley reports an injury of 95 per cent in small home orchards in Helena. Mont. There are man}' regions in this faunal area in which the insect does about 25 per cent daniat.'-e. and for some reason, prob- ably climatic, the injury is reduced to almost nothing for sevei-al 3'ears, after which the numbers of the insect gradually increase. Professor Aldrich records that in 1899 an early snowfall and low tem- perature at Moscow. Idaho, killed a great many of the larva*. There are many other localities in the Pacific Northwest where the codling moth either has not been introduced or has not thrived, and in which the injury is nominal. In man}' regions where the transition zone is pierced 'oy valleys of the upper Sonoran zone the orchards near the canyons suffer nuich greater injury than those more remote therefrom. Professor Piper has noted several cases in which this was true, and in one the damage was 75 per cent or over. THE PACIFIC COAST TKANSITIOXAL AREA. This area includes those portions of Oregon and AVashington be- tween the Coast Mountains and the Cascade Range, yjarts of northern California, and most of the coast region of the State from near Cape Mendocino southward to the Santa BarV)ara Mountains. In Oregon varying percentages of injury have been reported, ranging from a nom- inal loss to 75 per cent. In the Hood Kiver Valley in some cases it is greater than this, with an average, perhaps, of about 25 to 9U percent. rrPEK AUSTRAL ZONE. The upper austral zone is divided into two areas by reason of the greater humidity of the eastern portion. THE CAKULIXIAX FAUNAL AREA. This area includes the great apple regions of the Central States and many smaller portions of the Eastern States. Many entomologists have reported injury in these areas as ranging from 3U or 50 percent to practically lOU per cent. CPFEK JSONORAX FAUXAI. AREA. This area includes that portion of the upper austral zone west of the one hundredth meridian. From manv countinirs and estimates from various sources we find that in badly infested districts the injury varies from S<> to 95 per cent under normal conditions, and it is very common to find the loss reach lOU per cent. L(^WKK AUSTRAL ZONE. In tliis zone there are only a few localities where apples are grown on a commercial scale. Under normal conditions in badlv infested 16 localities the loss is almost total. Gaivia records, from check trees in si>rayiiig experiments, that the loss varied from 67 to 99 per cent. There are many localities in this zone in both east and west where apples can be grown, but on account of the injuries due to the codling moth other crops are grown instead. IMMUNE REGIONS. hi man}' regions of the Far West one often hears the fruit growers say that on account of the peculiar climatic conditions of that region apples are free from injui-y and the codling moth can not exist. Among these climatic conditions quoted are dense fogs, mountain breezes, and comparatively high altitudes. Seven or eight years ago it was thought that the Hood River Valley was immune from the insect; the same was thought of the Pajora Yallev in California; but later developments have shown that immunity was due to the fact that the insect had not been introduced into those localities. It has also been said that there was no codling moth near the coast in Oregon, but Professor Cordle^^ finds that it is present in some localities and believes that the former imnumit}^ was due to isolation. In many restricted areas in the Pacific Northwest more or less isolated the codling moth is either absent or present in such small numbers that it has not l)een observed. From past experience and examination of these localities it is evident that the insect in its gen- eral spread has not yet reached them. It is a question whether or not the insect will l)e injurious in these localities, but it is certain that it can be present. The writer has no hesitancv in concluding that there is no region in the Pacific Northwest in which apples are grown in which the codling moth can not exist. Many causes of immunity b}^ isolation in river valleys have been noted. The most marked case is at Mr. I. B. Perrine's orchard at Blue Lake, Idaho. The nearest orchard is IS miles distant down Snake River, while there are no orchards in the other direction inside of 75 to 80 miles. This orchard was free from codling moth until three or four years ago, the larvae having undoubtedly been intro- duced in old apple boxes about that time. MEANS OF SPREAD. There are several ways in which the codling moth can be distributed. The most prolific source of distribution comes from the shipping of fruit from an infested region. Fruit which contains the larval insects ma}^ be shipped great distances, and when the larvw complete their growth they spin cocoons, and in due time the moths emerge, and with unerring instinct seek the nearest apple trees. Many larvte are found to have spun their cocoons in the angles and cracks of the boxes Bui. 41, Div. of Entomo ogy, U. S. Dept. of Agncuitui Plate II. Fig. 1 .—Apple Leaf Inhabited by Codling Moth. a, Point where larva entered midrib, at junction with one of the principal veins; 6, portion of burrow exposed (photograph by Prof. A. B. C'ordlevj. Fig. 2 —Apples Damaged by Unknown Caterpillar. (Reduced from pliotograph t>y the author, t Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate III. Eggs of the Codling Moth. Natural size of eggs at (t and b: ( . showiiii: ivd riiijr in oirjr; «,<. oirjr. showintr the hole through which the hirva emerged: li. showintr tlio eirv' enlarged, with the larva inside: <». the end of the ovi}>ositor of the feniali'. (From SliTigerland. ) 17 or baiTcLs. In iminy localities it has been the _ractice to return to the fruit grower for refilling boxes in which fruit has been marketed. This practice has supplied the means of rapid distribution in such ocalities. If infested fruit is shipped any distance in cars the larvae spin their cocoons in cracks and holes in the walls of the car and may be carri(?d great distances before the moths emerge. This is thought to have been the source of the infestation at Kalispell, Mont. When apples are stored bv commission houses the larvie may crawl into boxe,^ or cases of various kinds of merchandise and thus be wideJy distributed. In sections where the orchards are near each other the spread is accomplished b}^ the moth flying from one to another; but when they are man}^ miles apart, which is especially the case in the Far West, this means of distri))uti()n doubtless has little influence. The insect can probably fly a few miles with the aid of the wind, but ordinarily 4: to 0 miles from a source of infestation, over unimproved land, gives partial if not complete immunity. We have no authentic record of the distribution of the codling moth with nursery stock, but one can readily see how this could occur, as the larva? might be in the cracks in the ground d round the trees or night crawl into the packing and thus be carried great distances. ESTIMATED LOSSES. Of all the insects aflecting the apple the codling moth causes the greatest loss, and many estimates have been made of the damage. In 1889 Professor Forbes indicated an annual loss in the State of Illinois of ^2,375,000. It is estimated that in 1892 the insect caused $2,000,000 loss in Nebraska. Professor Slingerland estimated that in 1897 the insect taxed the apple growers of New York 82,500,000 and the pear growers $500,000. In 1900 one-half of the crop of Idaho was dam- aged, while in 1901 the loss was much greater. ]\lr. McPherson esti- mated the loss in Idaho in 1902 as $250,000. In many sections of the Pacific Northwest the annual loss is from 50 to 75 per cent. From the nature of the case it is most diflicult to estimate the annual loss in the United States on account of the many factors which enter into the problem. By taking the estimates of the annual crops of apples as given by the American Agriculturist, it is found that for the years 1898, 1899, 1900, 1901, and 1902 the average crop was 4-7,000.000 barrels. From 1896 to 1902, inclusive, the average price at New York, Boston, and Chicago on Octo])er 20 of each year did not exceed $2. Allowing $1 for packing, transportation, and other charges, for «The estimates under this heading have been revised from the original figures given by the author to correspond with the latest data. — C. 1^. !M. 1)514— No. 41—00 2 18 •i7jJ(H),0()U barrels at |1 we have a cash valuation of $tl:7,()0(),()()0 for the iirst and second qualities. It is well w^ithin the limits of safety to estimate that one-fourth more apples would have been placed on the market had it not been for the codling- moth. This one-fourth would be about 12,000,000 barrels, and would have no value except for cider or local sale at very low price. The average price for cider apples is about 30 cents, which price would yield a total of about 13,600,000 as the value of the windfalls, culls, and cider tipples, while if the}^ were average apples, at $1 net per barrel the value would be $12,000,000, showing an annual loss of aliout $8,100,000. The loss in home orchards, in which the percentage of loss is far greater than in the commercial orchards, is estimated at $3,000,000, giving a total annualloss of 111,100,000. The loss in the countrv at large or an}^ section of the country will vary with the size of the apple crop. In ^^ears of full crops the com- parative injurv is not so great as in years when the crop is small and the prices high. FOOD HABITS. This insect is essentially a feeder upon rosaceous fruits, and to them all of the in]\uT is done. FRUITS INFESTED. The apple is by far the most infested fruit. It is the natural food of the codling moth, and under ordinarA^ circumstances is the only fruit injured, save pears. It is quite safe to assume that the larvt^ of the codling moth originally fed upon the leaves of the apple and that the habit of Inirrowing in the fruit is acquired. Much has l)een said and written as to the resistance by different varieties of apple to this insect. In Bulletin 35, new series, DiA^sion of Entomology, the writer gave a list of \'arieties and indicated the resistance. It is a notable fact that the summer varieties of apples are very attractive to the second gen- eration of insects. Varieties which are fragrant, as the Pewaukee and Ortley (Bellflower), are always badl}^ infested. As a general rule, one can say that the harder and less ripe late apples are not attacked to the same extent as those which are ripe and fragrant when the second generation enters. It is impossible, from the nature of the case, to determine the exact ratio of resistance of the varieties. In one orchard one will lind fruit of the Ben Davis variety least infested, while in another it will be the most infested. These differences are without doubt due to local conditions in the different orchards. Pears are next in order of infestation. Under ordinar}^ conditions they are not injured to any great extent. Jn the Pacific Northwest in badly infested localities the injur}" rarely reaches a total of 20 per cent. When remedial measures are used this is reduced to from 5 to 15 per 19 cent. Several pciir orchards have been noted which w(?re located in neglected orchards in which there were few or no apples. The second generation of the insect seemed to concentrate its destructiveness on the pears, and in one case fullv SO per cent and in another about .50 per cent were injured. One fruit grower in Texas reports an injur}' of .50 per cent. Crab apples are not usually so l)adly infested, l)ut instances have been observed where they suffered fully as much. Many records also show that peaches, prunes, plums, cherries, quinces, and apricots are infested b}' the codling moth, })ut under ordinar}' conditions their injury amounts to practically nothing. In cases where there is a lack of apples and the infestation is very abundant considerable damage results. There are records of -to per cent injury to peaches where the trees were quite near an apple house in which infested fruit was stored. NTJT-FEEDING HABITS. There are several European records of this insect in walnuts and oak galls. In 1887 Dr. Howard carefully sifted these reports, and concluded that the evidence was not sufficient to delinitely prove that the insect ever feeds upon either walnuts or oak galls; and it was highly probable that the larvie. if they were larvie of the codling moth, went into the latter for the purpose of spinning their cocoons. In 1895 Mr. Adkin exhibited a specimen of C. ponumdla which was bred from a species of chestnut, and in 1896 gave details as to rearing this insect from walnuts, and offers the explanation that these nuts bear fleshy coats, or that the insect was originally a nut feeder. Theobald in 1896 wrote that in his investigations, extended over many years, he had never himself bred CarpocajjsajjoiuoncUa from walnuts, but had found both C. splendana and Plodia intei'punctelln. ^Ir. West stated that he had also bred the insect from chestnut. Dr. Kiley in 1869 recorded that he had a specimen of a moth which had been bred from the sweetish pulp of a species of screw bean {Stronibocarpa ino)wica) obtained from the Kocky Mountains. Pro- fessor Cockerell raises the question of the correctness of this record. In 1894 Professor Bruner reported that it is highly prc)])al)le that the insect feeds in the seed ])uds of roses. In 1901 the writer carefully searched over man\' hundreds of these seed buds of roses near a badly infested orchard, and did not succeed in finding a single one that was in any way injured by the codling moth. LEAF-FEEDING HABITS. Professor Card in 1897 recorded that the young larv;e, especially in confinement, nibbled portions of the leaf. The writer has noticed manv times leaves that had been eaten where he thoui:ht the work 20 was done b}^ this insect. Professor Cordley has succeeded in making some observations upon this leaf-feeding habit which are of great value. In a recent letter to the writer he details his experiences as follows: It was found on June 4 that these eggs had hatched and nearly all of the larv;u were dead. Two of them, however, had fed upon the leaves, were yet alive, and had made some growth, notwithstanding the fact that the leaves had been taken from the tree nearly a month before and were therefore presumably not in the most palatable i o - dition. Both larvie were feeding upon the lower parenchyma of the leaf, and one had completely covered itself with a web holding pellets of frass. A recently hatched larva, mounted in balsam, measured 1.35 mm. in length; the larger of these two larv£e at this time measured 1.80 mm. in length and was proportionately stouter. Both Avere transferred to fresh leaves, upon which they fed until June 8, when one of them disappeared. The other continued to feed until June 11, when it too disap- peared. However, I noticed a slight discoloration of the uiidrib of the leaf, near where this larva had been feeding, and on carefully opening it found the larva feeding as a miner, it having already excavated a tunnel about 15 mm. long. I then examined the other leaf, in which I found the larva that had disappeared three days before •likewise feeding in the interior of the midrib. The larv{\3 were again transferred to fresh leaves, and by the following morning each had again disappeared within a midrib. Both larvse continued to feed within tha midribs until June 16, when one of them, on being transferred to a fresh leaf, refused to eat and soon died. The other, with occasional changes to new pastures, continued to thrive until June 25, when it was plump and active and apparently in the best of health and spirits. Unfortunately I was then absent from the laboratories for some days, and when I returned the larva was dead. I believe that with careful attention it could have been brought to maturity on a diet of leaves alone. When one considers that it lived and grew for more than three weeks upon leaves that had been severed from the tree sometimes for several days, and that it was apparently more thrifty between June 16 and 25 than in the earlier days of its existence, one must acknowledge that, while the proof is by no means positive, the indications are that codling moth larvje may fully develop on a diet of perfectly fresh apple leaves without ever having tasted fruit. (See PL II, fig. 1.) The writer has man}^ times taken larvae from apples and placed them upon leaves in cages and bottles. It was found that the larvae would fasten the leaves together with silk and eat holes in them; but on account of lack of attention no larvie were bred to maturity. The writer believes, and agrees with Professor Cordley in believing, that the larvas with proper care can be brought to maturity on the leaf diet alone. This (][uestion of the leaf -feeding habit of the codling moth is one of the most important questions in the life history of the insect, and should especiall}^ commend itself to entomologists for future investi- gation, since not only will it give us a very important biological fact, but it will also prove very definitely how sprajdng is efiective against the insect. It has often been recorded that larvae gnaw cavities in rough rotten wood, bark, cloth, paper, and other places where the}^ spin cocoons, and the bits of these substances incoi-porated in the cocoons. From 21 observation it is evident that the larvte do not eat any of these sub- stances. When Paris green was phiced under the i)ands and on the bark and in other places where the larva^ spin, it was found that none were killed, even when the poison was abundant, wiiich tends to show that they do not eat of these substances. PRIMITIVE FOOD HABITS. Writers have indulged in speculation as to the primitive food habit of this insect. The other species of the genus are nut feeders, and Adkins expresses the opinion that this insect was originally such, and that the habit of eating apples was acquired. The older writers have said that the insect was prol)ably a leaf feeder. From the experience of Professor Cordley this view appears to be the more probable one. WORK OF OTHER INSECTS. There are many other insects which feed on apples whose work may be taken for that of the codling lyoth by those who are not familiar with the characteristics of the respective insects; but in all instances there are differences in the work and habits of the insects by which they may be easily distinguished. The apple raaggot {TrypetajxnnoneUa). — This insect is ([uite injuri- ous in the northeastern States, and its work in the apple is characterized b}^ many winding tunnels through the fruit. The larva is footless, and has no distinct head, but tapers toward the front. This maggot is the early stage of one of the two- winged flies. TJie ])e(icJk Uvig-horer {A)}((rsia lineatelJa). — Injury to peaches and plums by this insect is often at- tril)uted to the codling moth, as its second generation feeds in the fruit. The larva^ are nuich darker red and much smaller than those of the cod- ling moth, and the mature larva tapers toward either end (tig. 1). The pliun r}(rr}ili<) {Cn)}<)tr<(ch(h(,'i n( nKj)hunctur(^s caused by the adult in feeding, and by the fact that the larva, though it has a distinct head, is footless. The Tndian-we<(l vHffh {Plod in i})f< rpuiuiella). — This inset't feeds upon edibles of nearly all kinds— meal, grain, seeds, nuts, dried fruits. Fu;. \.—Annr!tia UncntrUa: a. twig of poaoh, showing in crotrh minute masses of chewed hark ahove larval ehambers; /), latter mneh enlarired; c. a larval eell. with contained larva. m\ich enlaryfed: ti, dorsal view of young larva, more enlarged (from Marlatt>. 22 etc. There is a common notion among some farmers that the larva of this insect is that of the codling* moth, and the writer has often ])cen told that the codling moth was introduced ))y its larvte being imported in dried fruit. We have no reliable rec- ords of the codling Fig. 2.—Plodla interpnnctelki f, same, dorsal view — somewhat abdominal segment of caterpillar- den^. moth: /), chrysalis; e, caterpillar; t enlarged; d, head, and r, first more enlarged (from Chitten- moth having ever eaten dried fruit, and the Indian-meal moth is the princi- pal insect that has been reared from such sources. The caterpillar is much smaller than that of the codling moth, -The larva of this and can be easih^ distinguished from it (tig. 2) T/ie apple fruit-ininer {Argyi'esthJa conjugeUa) insect has been found attacking apples in British Columbia, and injuries which may have been caused by it have been noted in Washington, Idaho, and Montana. The larvje are about one-fourth of an inch in length, are of a dirty Avhite color, tinged with reddish when full grown, and taper at each end. The tunnels made in the fruit are numerous, and extend in all directions. There are two species of Lepidoptera which do great damage to apples in Japan, which may sooner or later succeed in en- tering this country. Apple find f -hover (La rem a h ereJlerd) . — This insect is said to have gained a foot- hold in British Columl)ia. The larva^ live only at the core of the fruit, injuring the seeds. When full grown they make a pas- sage out, crawl or drop to the ground, and spin a white cocoon in the earth. They hibernate as pupae, and there is onlv one generation each year. The species is shown in fig. 3, which also illustrates its manner of work. Pear frult-hrrer {Xephoj>tery;r ruhizonella.) — It is stated that in Japan the pear crop is injured to the extent of 30 to .50 per cent each 3^ear by this insect. The eggs are laid in clusters on the twigs and Fig. Z.—Lavcrna hcrdlcm: a, adult; b, same, side view; c, larva; d, co. co6n; r. injured apple— all slightly enlarged except r, which is reduced (redrawn from Matsumnra). 23 h leaves, the larva makino- its way thence to the noarbv fi'uits. which it enters. The principal work is around the core of the pear. The larval stage lasts three weeks or nioi-e. and the pupal statue is passed within the fruit. The insect hibernates in the egg stage. The moth, larva, and pupa are illustrated by fig. i. UnJcnovm caterpiUar irorkhig on outer 8m\face of apjjles. — Opportunity is taken of pre- senting the reproduction of a photograph of apples injured by an insect, which in its larval stage somewhat reseml)les the codling moth, but which we have as yet failed to rear and identify. The injury was first brought to the attention of the Division of Entomology by Mr. D. W. Coquillett in October, VM)\. The apples furnished were pur- chased in open market in the city of Washington. The in- jur}" appeared to be almost ex- clusively on the outer surface, consisting in the cutting away of the skin and disfigurement of the apples and considerably depreciating their value as salalde articles (see PI. II. fig. "2). In some cases holes entering the fruit to the depth of about one-fourth of an inch w^ere found: in one apple to the depth of one-half inch. In November Dr. L. O. Howard also furnished specimens of apples showing injury by tlu* same s])ecies. One of the larva^ spun up and formed a cocoon Xov(Mnbcr (>. Unfortunately all tln^ larva' died with- out our securing the moths. The folhnving i)ricf description of the larva was made: Keddinli flcsli-colored, head dark ])i()\vn. central ]K)rti(Mi of face whitish and trans- parent, with two black spots; cervical shield transparent, except for caudal niarjrin Three seta^ on the i)re-spiracnlar tubercle. Lenirth, live-eighths of an incli wlien sj)inninptrnj.v rnhrizomlUi: r.dult al)ovo. larva just beneath, eg? mas.s on twig at right: damaged pear with pupa at left — all natnral size (redrawn from M a tsu m u ra ^ . 24 LIFE HISTORY. Of all insects the codling moth has the largest number of ])iog- raphers. It has been studied in nearly every country in the world and in all climates in which it exists. The early accounts were always more or less vague and inexact and gave rise to many false ideas. Gradually these points were worked out until to-day we can say that the life history of the insect is as well if not better known than that of any other. Yet, with all the knowledge we have of it, there remain several important points to be determined by future work. It is a fundamental principle of economic entomology that in order to successfully combat an insect the life histor}^ of that insect must be given a keen, searching stud3\ With few exceptions these studies reveal some point in the life of the insect at which it is vulnerable to preventive or remedial measures. Without this knowledge efforts are wasted and in some cases are a positive aid to the insects. It can not be too strongly urged that each fruit grower make himself familiar with the life histor}^ of the codling moth from personal observation, for by doing so he is placed in a position to understand the reasons for measures of control and to exercise his ingenuity in applying the same to his own orchard. The ease with which collections can be made in the larval stage and the accessibility of literature pertaining to it should specially com- mend this insect to teachers as a subject for nature-stud}^ lessons. In the present studies upon this insect particular care has been taken to keep the different stages under observation in exactly the same con- ditions of temperature, moisture, and light as were present in the orchard in which the cages were located, and as a result the writer is able to present some definite data in regard to the effect of temperature upon the length of the stages of the insect under normal conditions. As in other lepidopterous insects, the life of the codling moth is divided into four distinct stages — egg, larva, pupa, and adult. In the winter and early spring the larvae ma}' be found in their cocoons in various places, as in cracks and holes in the trees. Later the larva transforms into a pupa, and this in turn changes to a moth, which in turn lays eggs. THE EGG. Since the time of Roesel many authors have mentioned the egg of the codling moth and stated where it was laid, l)ut it was as late as 1893 that it was first accurately described and figured. In 1874 Mr. W. H. Hurl but described the egg as being about one-eighth of an inch in length and nearly white. Riley described it as being very small and of a yellow color. Messrs. A. J. Cook, Koebele, Weir, and others undoubtedly saw the eggs, but Cook in 1881 and Miss M. Walton doubtless saw the eggs of some other insect. 25 111 1893 Profes.sor Wash])urn oavo fm accunito description of the egg. with the first ligure of it. This tigiire shows a well-formed enihryo inside, but the netwoi'k of ridges near the center is much too open. Slingerland in ISOG and Card in lb'.»7 distinguished the i'^^g> and made many oVjservations which added material!}' to our knowledge of this stage. In hi> ISHS bulletin Slingerland publishes many excellent photographs and descriptions which caused the eggs to be familiar objects. Influenced In' Slingerland's and Card's work. Aldrich. Cord- le}^ Gillette, and others have from time to time added to the sum of our knowledge of this stage of the insect. It is remarkable that, in spite of the many studies of its life history, the ("gg escaped notice for so long and when seen was not described and tigured until a com- paratively late date. The egg is a flat, somewhat oval-shaped objec-t with a flange around it. It varies in size from ('.HB to 1 by 1.17 to 1.3i! nun. Commonly speaking, it is about the size of a pin head. The surface is covered with a network of ridges which are much closer together toward the central portion than around the edge. The color depends upon the age of the embryo: as when the egg is tirst laid it is of a pearly white color, sometimes with a decided yellowish tinge: later it is darker on account of the red ring. The egg:< are always glued to the apple or leaf and one often finds shells which remain for some time after the larva has hatched. The reflection of light from the egg is of the greatest aid in finding tliem. and they have often been described as reflecting the light like "trout scales." (See PI. III.) PLACES WHERE LAID. Having never seen the egg^ the early writers were forced to guess as to where it was laid. They stated that the egg:< were laid either in the stem end or in or about the calyx end of the apple. These views were held because of the position of the entrance holes of the larva\ These ideas were published again and again for over a century, and American writers copied them until about 1897. when, by a series of observations, it was proved that they were incorrect. In 18S9 Koebele and Weir stilted that the eggs are laid at any ])oint upon the apple and are "as a rule laid elsewhere than within the calyx." Wasjiburn in 1892 found that the eggs were '"placed on Ijoth sides and the top of the fruit." In the spring of 189() Slhigerland found that in con- finement the moths laid egos on the sides of the cages, on leaves, and on bark. Card in lSi«7 found that th(^ i^^gs were laid almost exclu- sively upon the upper surface of the lea\es. and in 1897 only 2 eogs were observed in the field. In a recent letter Professor Cordlev states that out of IT) eo-o-> laid in contiiuMniMit tlie o-nnit(M- numbtM- wt^'e 26 on the fruit, and that he has never seen an ego- of the first generation upon the fruit in the field. The apparent contradictions of these observations may be accounted for by the fact that they were made upon the eggs of different gener- ations of the insect. The writer has found that in Idaho but few of the eggs of the first generation are laid upon the fruit. In one limb cage a moth laid 21 eggs, only one of which was upon the fruit; and in another cage 24 eggs were laid and only 2 were upon the fruit. Very few eggs of this generation were observed to have been laid upon the fruit in the field. Professor Cordley suggests that the moth does not lay eggs upon the young fruit on account of the pubescence, which is afterwards lost. This is most probabh^ the cause. In the field one can often find fruit, surrounded l)y leaves, upon which there are no Qgg^, while several may be found upon the upper surface of the leaves. A good percentage of the ogg^ of the second genei'ation are laid upon the fruit in the field. When the fruit is scarce a larger numl^er is found upon the leaves. The average of several rough countings in the field gave an average of aliout 50 per cent laid upon the fi-uit. Breed- ing records show that out of 175 eggs of this genei'ation in liml) cages on inclosed branches and fruit there were 71 eggs upon the leaves, 95 upon the fruit, and 0 upon the twigs. Very few eggi^ are laid upon the underside of the leaves, and it seems that the moth much prefers a smootli surface upon which to oviposit. We mav therefore conclude that the eggs of the first generation are for the most part laid upon the leaves, while the majority of those of the second brood may be found upon the fruit. WHEN THJ: EC4GS ARE LAID. Various writers have stated that the eggs were laid at night. Coole}' records that he observed a moth depositing eggs at about sun- set. The writer's observations show that the oviposition for the most part is accomplished in the late afternoon or early evening, while a single o))servation shows an Qgg to have been laid sometime between 9 and 12 o'clock in the morning. THE NUMBER OF EGGS LAID BY ONE FEMALE. There is probabh^ less definite data on this point than on any other in the life history of the insect. Man}' guesses have been ventured as to the number of eggs that one female will lay, varymg from 12 to 300 and over. LeBaron found from 1:0 to 60 eggs, with an average of 50, in various stages of development, in the ovaries of the female at the time of emergence. He adds that if all the undeveloped eggs came to maturity this number must be increased. Matthew Cooke said that he had a vial in his possession in which a codling moth laid 85 27 eggs. The wri toT was una])le to secure eggs in this wa}'. In onl}- two instances has the writer made definite observations on the number of eggs laid by a single female moth. Two pairs of moths were secured in copula and placed in separate limb cages. In one cage 21 eggs were found, but as the moth escaped the observation was incon- clusive. In the other cage 25 eggs were laid, but a spider put an end to the experiment before a definite conclusion was reached. In view of these incomplete observations the writer can only venture an opinion that the maximum number of eggs laid by one moth is about 50, with the average between 30 and -10, which is comparable to defi- nite records of other insects of this family. THE EGG-LAYING PERIOD. Upon dissection of the ovaries of the female of the codling moth the eggs are found in various stages of development. It is also noted that eggs are laid Avhen they are in different stages of maturity. From these facts we ma}^ conclude that the egg-laying period extends over some time. Various authors have given the length of time from the emergence of the moth to the beginning of the laying of the eggs as from 48 hours to 6 or 8 days. Professor Gillette gives the time as al)out 5 da3^s. The various records of writers show that this time varies from 2 to 7 days, with an average of from 4 to 5 days. DURATION OF EGG STAGE. In 1746 Roesel stated that the egg hatched in 8 days. Recent authors give the length of the stage as follows: Le Baron, one week: Wash- burn, 5 to 10 days; Rile3% 4 to 10 daj^s; Slingerland, one week; Card. 8 to 10 days; and Professor Gillette, 0 to 8 days' in his lal^oratorv. with a known temperature, and in the orchard one day longer. CooU\v records 12 da3^s as the length of the stage of one egg. The results of observations upon KU eggs and observations of Pro- fessor Cordley are given in Table I, with the total and average effect- ive temperature to which the (\o-gs were subjected. T. UU.E I. — Dnntfion of ( Oil >^t(t t) 8 9 12 li 12 2tH; 2i;(". 217 217 .",.V" Aug. 1() 9 Aug. 2(; 28 28 Table I. — Duration of egg stage of codling moth — Continued. Date laid. Number Date Number laid. hatched. hatched. 1902. 27 Sept. 5 8 Sept. 6 14 Sept. 8 2 61 Sept. 8 3 Sept. 9 4 Sept. 12 32 Sept. 15 2 14 Sept. 9 1 Sept. 6 11 Sept. 15 1 40 Sept. 8 3 Sept. 9 : 5 Sept. 12 3 Period of incuba- tion. Total ef- fective tempera- ture. Average effective tempera- ture. 1902. Aug. 27 Aug. 28 Do Aug. 29 CORDI.EY Mav7 "Do June 1 Mav 12 Days. 243 o p 278 307 360 269 295 364 428 216 269 428 254 286 349 298 285 o jp The results under normal orchard temperature give the length of the stage from 9 to 18 days, with a weighted average of 11 da3^s. This average is longer than has been given by other authors, which may be accounted for b}^ the fact that it is the usual custom to keep the eggs in laboratories rather than under normal orchard conditions, and that the times of the laying of the eggs were estimated. HATCHING or THE EGG. Recent authors are quite well agreed as to how the larva breaks or eats its wa}^ out of the shell. Professor Slingerland was most proba- bly the first to observe this operation. He states that the larva came out of the egg near the edge at one end through an irregular crack in the shell. (PI. Ill, es.) The writer has never observed this emer- gence, but upon examining many egg shells an irregular crack was always found which was almost always at one end of the shell. CHANGES DURING INCUBATION. When laid the egg is of a translucent pearh^ color, often with a j^ellowish tinge. Observations upon 88 eggs show that from 2 to 6 da3^s with a weighted average of 3 da3\s after being laid a red ring makes its appearance. This ring appears graduall}^ at first whitish, then yellowish, and later quite a brilliant red. B}' observations upon 56 eggs it was found that in from 7 to 10 days, with a weighted aver- age of 8.1: da3^s after being laid, the egg loses the ring and in its place the larva can be seen, the " black spot," which consists of the head and cervical shield, l^eing the most conspicuous pai't. Professor Gillette states that his assistant, Mr. E. P. Ta\dor, found the red ring to appear in from 2 to 3 diiy>^ after laying and the black 29 spot appeared 2 to 3 da\'s later. This shorter averao-(! may ))e account(;d for by the fact that these eg^'s were kept at a higher tem- perature than normal. METHODS OF OBTAINING EGGS. There arc two ways of obtaining eggs for .study. The first is to collect them in the field and place them under observation in cages. There is a serious objection to this method, as there is no way of knowing the age of the eggs. The second method, that of confining larva3 and pup« and allowing the moths to emerge, is far moi'e satis- factor}- . If these moths are placed in a cage over a limb of a tree, one will find eggs in abundance in a day or two. One is sometimes fortunate enough to find moths in copula, and in that event they should be placed in a separate cage. B}^ determination of sex of the various moths nuich more vahiable data can be secured. Care must be taken that too many eggs are not laid in one cage, as in that event it is difficult to keep accurate notes. These limb cages are bags made of mosquito netting of finer mesh than the ordinary netting. By this method the leaves and fruit are alwavs fresh and the conditions are exactlv the same as in the orchard. INFLUENCE OF TEMPERATURE UPON THE LENGTH OF THE EGG STAGE. It has often been stated that a higher temperature caused the eggs to hatch in a shorter time, but onl}^ a few definite observations have been recorded. The temperature used in these calculations is the effective temperature, which is obtained by subtracting 43" from the mean daily temperature as recorded by the United States Weather Bureau station at Boise, Idaho. Professor Gillette gives 6^ daj^s as the length of this stage at a tem- perature of from 68° to 70° F. and 6 days as the time in a greenhouse where the temperature was 110° F. at midday. In Table I the total and average effective temperature is given from the time the eggs were laid until they were hatched. These data are arranged accord- ing to the temperature in Table II. Tahlk TI. — -Kfective teiiipenfturc ((ud jxriod of iiicuJxttio)). Average Total Average Total Average Total effective effective Length eflfective eflfective Length eflfective eflfective Length temper- temper- of stage. temper- temper- of stage. temper- temper- of stage. ature. ature. ature. ature. ature. ature. or. ° F. Bays. °F. ° F. Days. °F. OR nays. 12 298 24 24 217 9 25 2M 10 18 216 12 24 269 11 •JSO 11 19 228 12 24 295 12 ■2~ 307 10 19 253 13 24 349 14 •_>7 3(56 12 22 247 11 24 364 15 2i) 269 9 22 260 12 24 428 18 30 278 9 23 206 9 24 428 18 47 285 o ' 23 276 12 25 247 14 Average total effective temperature, 302° K 3,0 This tal)le i« not complete, in that not sufficient observations were made at lower and higher temperatures; and it is dangerous to make any extended conclusions therefrom. A study of the table shows: First. Under a low temperature the length of this stage is longer than at high temperatures. Second. The total temperature varies from 200'^ to •i28'-' F., and the average is 802^; and in general eggs have to be subjected to this amount of heat before the}^ hatch, whether it be for a longer or a shorter period of time. Third. The eggs are not at the same state of maturity at the time of oviposition, as at 2J:"^ w^e have from 9 to IS daj^s as the length of stage. Fourth. Under normal held conditions a small ditference in temper- ature causes but little chantre in tlie lenoth of the stao'e. So o MORTALITY AIMONd THE EGGS. Various observers, among them ^^'ashburn, Goethe, Card, Slinger- land, and Cordley, have found that many eggs of this insect did not hatch. There is little doubt that at least one of tliese writers mistook eggs from which the larva^ had hatched for dead eggs. The writer has noted that man}' eggs became hard and dr}', Avhile in others the contents changed to a dark l)rown color. These changes may have been caused by infertility, parasites, or the excessiveh' hot sun. The mortalit}^ as shown by our breeding-cage records is ))y no means so great as the writer had supposed. The eggs, however, were more or less protected. THE LARVAL STAGE. Considering the codling moth in its economic relations, it may be said that the larval is the most important stage of the insect. Not only is it distributed, and does all of its damage in this stage, but it is more amenable to remedial measures. At the time of hatching the young larva is from one-twentieth to one-sixteenth of an inch in length, of a semi-transparent whitish or yellowish color, with large, shin}^, black head, and dark cervical and anal shields. The body shows regularly arranged spots with short hairs or setee. If hatched upon the apple the 3'oung larva seeks a place to enter, which is in general some irregularity upon the apple or at the calyx. Slingerland, Card, and Cordley have made many excellent observa- tions upon the place of entrance. When hatched upon the leaves they may not find an apple for some time, and su])sist by eating .small por- tions of the leaves. In confinement this often occurs, but it has never been determined accurately how often it takes place in the field. The writer has time and again noted these spots on the leaves in the field, and has noted also that larvae hatched on leaves would have to go from 31 10 to 20 feet before thc}^ could find an tipi)le. Card notes tliat conipara- tivelv few eat of the leaves in tlie open, ))ut from such observations as we have the writer is strono-ly of the opinion that it is (|uite a gen- eral habit. DESCRIPTION OF FULI.-GROWN LARVA. When full grown the larvte are about three-quarters of an inch in length, and their heads measure from 1.51: to 1.76 mm. across the broadest portion. The majority are of a pinkish or flesh color, which is much lighter or absent on the under side. It was thought for a long time that the pink color was due to the larva having fed on some particular varieties of apple; but the white and pink larva? have often been found feeding on fruit from the same tree. The head is brown in color, with darker markings, while the cervical and anal shields are much lighter. The spots in which the minute short hairs are situated are but little darker than the body wall, but can be easily distinguished with a hand lens. The mandibles are the most noticeaT)le feature of the mouth parts. Beneath the under lip is the spinneret, from which the silken thread is drawn. The larva has eight pairs of legs. The first three pairs, or true legs, are situated on the thorax, and are three jointed. Later these form the legs of the adult insect. The five pairs of fleshy abdominal legs, or prolegs, disappear in the pupal stage of the insect. The first four pairs of legs are armed with circles of hooks, w^hile the hooks on the two pairs at the end of the body are arranged in a semicircle. The spiracles or breathing apertures of the larva are arranged on either side on separate segments of the bodv. (Pl.V, fig. 1.) ENTERING THE FRUIT. The usual place of entrance of the first generation is by way of the calyx. The larvie either scpieeze their way into the calyx between the lobes or tunnel into the cavity at the base of the lobes. A scar, the stem, or a place where fruits touch is often selected as the place of entrance. In 1900 the writer observed an ego^ shell with a larval entrance hole at the edge and partly imder the shell. In view of later observations it is more probable that some larva crawling around found this obstruction and entered, rather than that the larva entered the fruit directly from the shell. The second generation for the most part enter on the sides of the fruit. The larva crawls rapidlv about the apple, seeking a place for entrance. A scar or roughness is a fa\orite place, as the jaws slip on the smooth skin. In its wanderings tlie larva spins a silken thread and finally makes a web over the surface of the ai)})le. With this as a foothold it is able to make some impression upon the skin, which is bitten out in chips and dropped into the web. Later, when it is partly covered, the larva l)acks out of tlu^ burrow and brings ])iiH'es out with 32 it. Thio is repented until it is entirely within the burrow, when it tui/js around and spins a silken net over the hole, in which may be incorporated several pieces of the fruit. (PI. IV, fig. 1.) Slingerland, Card, and Cordley have also noted these larvae enter, and the observations made by the writer agree entirely with theirs. One of the essential points noted is that Avhile entering none of the larv83 seem to eat any of the fruit until well within the burrow, and it most probabh^ gets some of the poison applied in spraying when it attempts to pierce the skin. The writer has observed numerous larger larvie, and is quite positive that they do not eat any of the fruit while they are entering. PLACES OF ENTRANCE. The places of entrance of the successive broods are quite different. Various authors have stated that from (>() to 80 per cent of the larvi^ of the lirst generation enter the fruit bj^ the calyx. In IDOl several countings gave an average of 83 per cent, with a minimum of 79 per cent. In 190'2 much more extensive countings gave a maximum of 93 per cent, a minimimi of 50 per cent, and an average of 81 per cent. (Table III.) Less than one-half of 1 per cent enter ))y the stem end, while the larger remaining percentage enter the side, especially where fruits touch. The majority of the second generation enter the side of the fruit. A few counts in 1901 showed that the greater part of the larv» entered the side, and a few cases showed that from 90 to 100 per cent had entered at that place. Countings on 1,478 apples in September, 1902, on both sprayed and unsprayed trees, are given in Table III. Table III. — Percentage of first generation entering calyx. SPRAYED TREES. Orchard. Variety. Date. Stem. Side. Calyx. Total. Per cent in calyx. McPherson Do Jonathan Ben Davis do July 18 July 22 July 19 0 0 0 2 2 8 2 28 8 23 30 16 91.8 93.3 D. Geckeler 50 Total 0 12 38 69 82.6 UNSPRAYED TREES. J D Gray July 17 July 19 July 21 .Tnly 25 July 22 July 31 2 0 0 0 S 31 38 4 7 21 67 62 23 23 236 13 100 100 27 30 257 15 67 bo . . .. 62 Do 85.1 Do 76.6 Dr. Collister Wealthy 91.8 McClellan 86.6 Total 2 103 424 529 80.1 Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate IV. Fig. 1.— Entrance Holes of Larv/e of the Second Generation. Fig. 2.— View in Orchard of Hon. Edgar Wilson. Showing Location of Affle House in Relation to Orchard. Fig. 3.— Another View in Orchard of Hon. Edgar Wilson, Showing Location OF Apple House with Reference to the Railroad. Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate V. Fig. 1.— Codling Moth Larva 'Enlarged About 3 Times). Fig. 2.— The Wormhole or Exit Hole of the Apple i'ENLARGED). Fig. 3.— a Wormy Apple, Showing the Familiar Mass of Brown Particles Thrown Out at the Blossom End by the Younq Larv/e ifrom Slingerland'. 33 Places of entrance of the second generation. UNSPRAYED TREES. Stem. Side. Calyx. Total. Per cent ' calyx. 4 66 57 127 44.4 5 74 31 110 28.1 12 104 76 192 39.5 4 97 41 142 28. H 1 20 12 33 36.3 1 58 14 73 19.1 27 419 231 077 .,2«.l 1 SPRAYED TREES. 1 56 28 85 32 11 204 21 236 8.8 0 37 36 73 49.3 0 41 14 55 2.5.4 0 32 9 41 21.9 0 50 34 84 40.4 0 19 18 37 48.7 0 50 21 71 29.5 1 11 12 24 50 0 32 16 48 33.5 0 22 7 29 24.1 0 9 9 18 50 13 563 ^ 801 a 28 « Average. The tables of the places of entrance of the first generation on sprayed trees show some interesting facts, and it is to be deplored that the records are not more extensive. No definite data was secured in regard ^ to what percentage of the larvae enter the sides where fruits are touching. In badly infested orchards it is almost impossible to find such fruits into which a larva has not entered. It would be safe to estimate that fully 50 per cent, if not more, of the larvae entering at the sides enter where the fruits touch. Immediately after entering the cal} x cavity the larva takes its first meal. We have a lack of data as to exactly what is eaten, l)ut most probably the larva acts as it does wlieiitthe side is entered. After spinning the web over the hole the larva, when it enters the side, eat^ out a cavity under the skin and throws out but little castings. This mine is eaten outward from the point of entrance, and in from :> to 5 days the larva begins its tunnel toward the center of the fruit, reach- ing that point when about one-quarter grown and about a week old. While at the surface, or while tunneling toward the center of tlie apple, the larva pushes its excrement and frass through the entrance hole. Later the entrance hole, especially at tlu^ calyx, is enlarged, and a considerable amount of frass is throw n out, which characterizes the infested fruit (PI. Y, fig. 3). A\'hen a considerable cavity has been made in the interior of the apple the excrement is bound togetJier with silk. Upon reaching the centi'al portion of the fruit the lar\a eats (5r)l.t— No. 41 vi3 3 34 out an irregular cavit}" about the core, and seems especially partial to the seeds. The insects pass through five larval stages, and increase in size by shedding their skins four times to allow for growth. The width of the head of the larva in these different stages averages as follows: First stage, 0.38 mm.; second stage, 0.55 mm.; third stage, 0.T8 mm.; fourth stage, 1.12 mm. ; fifth stage, 1.6 mm. When in the latter part of the first stage and the second part of the third stage the larva3 are whitish in color, but with the cervical and anal shields black, and with blackish spots around the setae. In the later stages the shields become brown, and the spots around the hairs are usually indistinct, especialh' in the pinkish larvae. TIME SPENT IN THE FRUIT. Yery few definite observations have been made in regard to the time the larva spends inside the fruit. Le Baron gave the time as four weeks; Riley, 25 to 30 days; Slingerland, 20 to 30 days; Card, 10 to 11 days; and Cordley, 16 to 21 daj^s. From the nature of the case it is most difficult to get exact data on this point, as there are many accidents which may prove fatal to the experiment. On only 5 larvae was the writer able to obtain results definite enough to use with any degree of confidence. One of these larva? remained in the apple 14 days, tw^o 18 days, one 21 days, and another 26 days. Professor Gil- lette kindh" furnishes some unpublished data on this point, in which he finds larvae to have stayed in the fruits 12, 18, 20, and 24 days, respectively, with an average of 19 days. The average of all these observations is about 20 days. PREPAKATTONS FOR LEAVING THE FRUIT. When about full grown the larva makes a passagewa}^ to the out- side of the fruit. This is usually made toward the side of the apple, in a different direction from that from the entrance hole. Rarely does the exit passage follow along or consist of the enlarged entrance passage. Before the larva has passed outside the outer portion of the passage is filled with a block of frass (PI. V, fig. 2, a), or a cap of silk is spun over the hole. LEAVING THE FRUIT. When ready to leave the fruit the larva pushes out this block or tears away the cap of silk, crawls out on the surface of the apple, and immediate!}" seeks a place in which to spin a cocoon. (PI. V, fig. 2, h.) If the apple is upon the tree the larvae will, in by far the greater num- ber of cases, crawl from the apple to the twig, from there to the branch, and thence down upon the trunk of the tree. Another method, which is compa]"atively rare, is that in which the larva lets itself down 35 to the oround by iiiean.s of a silken thread. This may he on account of the fact that the larvfe sometimes drop accidentally and use the silken thread to support themselves. It is not uncommon to find these threads extending through the branches of trees which are badly infested with the codling moth. Professor Gillette finds that 85 per cent of the larvte enter the bands during the night, and the remaining 15 per cent during the da}', in Auuu.st. Observations of the writer show that in the summer the larger percentage enter the bands from 6 p. m. to about 11 p. m.. at Boise, Idaho. After 11 p. m. it is usuallv so cool that there is but little activity. In September the conditions as given by Gillette are about reversed. The nights are cold, and the larvte are active onh' durino- the warmer Darts of the dav. at Avhich times thev enter the bands. If the apple has fallen to tne ground the larva simply crawls into a convenient place and spins its cocoon. After leaving the fruit the larva is unprotected, and does not consume much time in finding a place to start its cocoon. PLACES OF SPINXIX(r COCOONS. Ill orchards the cocoons are normally found in cracks or holes in branches or trunks of the trees, under scales of rough ]:>ark, and in the rough bark on the main branches of the trees. When the trunk of a tree is smooth the cocoons are often found under bits of bark and in the earth about the foot of the trees. Cocoons are found under anything on the tree or leaning against it, as bands placed around the trunk, rags tied aroiuid the lnnl)s. or boards and sticks leaning against the tree. When much fruit h s fallen the larva' seem to have a greater range in spinning cocoons, often placing them among clods of earth, beneath paper or any other rubbish on the ground, in the cracks and rough bark of adjacent trees, in piles of wood or lumber, in fence posts, and under the pickets of fences. In piles of fruit in the orchards the cocoons are normall}' found placed among the ap})les: in orchards where the trunks and branches of the trees are smooth, the cocoons are often found in the cracks of the earth about the foot of the trees, and when fi'uit is lying on the ground they ha\'e been found among the clods of earth \)y Cordley and ^IcPherson. Cordley published a photograph showing a cocoon on a clod of earth. In the writer's experience two cases have been ft)und in which a cocoon was spun inside of wormy fruit. It was impossible to tell whether or not the larva^ which had spun these cocoons were tliose which had done the injury to the fruit. In packing houses it is (piite conunon to tind the larva' in cracks of the fioor. walls, and roof, in piles of lumber or boxes, and in the angles and cracks of boxes or barrels used for han- dling tne fruit. The larva usually gnaws out a cavity in which to 36 spin its cocoon. These cavities are often found in the interior of rotten trees, stumps, and fence posts, with passages excavated into these rotten pieces of wood from 2 to tt inches. In the spring cocoons can be found only in the more secure places, those spun in more exposed places having- been eaten by their enemies. (See PI. VIII.) DESCRIPTION OF THE COCOOM. The cocoon is composed of silk, which is the product of the pair of silk glands common in man}^ orders of insects. These glands are sit- uated on either side of the alimentarv canal, and consist of three parts, each of which has a separate function. The cephalic portions unite to form a single tube in the head of the insect, which extends to the external opening or spinneret. The spinneret is a chitinous projection on the under side of the labium or lower lip. Throughout its life the larva makes use of this silk in various ways. When a suitable place has been selected for the spinning of a cocoon the larva begins to weave about itself this single thread of silk. The exterior outline of the cocoon conforms to that of the cavit^^ or crack in which it is placed. While spinning the larva is bent upon itself and decreases considera))ly in size. When the cocoon is completed, which takes usually about one day, the larva straightens out and con- tracts in length. While tne exterior of the cocoon may be rough, the interior is always smooth and oval in shape. At completion of the spinning of the cocoon the alimentary canal, silk glands, and other organs peculiar to the larva begin to disintegrate. In from 1 to 19 days, with an average of about 0 days, the larval skin is shed and the insect becomes a pupa. The cast larval skin can always be found at the caudal end of the body, shriveled into a rounded mass. Various authors have noted that when the cocoon of the codling moth is torn or cut open, it is immediately repaired by the larva. Professor Slingerland states that the damage is repaired in winter. He has also had a larva spin two or three complete cocoons after hav- ing been removed A^ery earl}^ in the spring from the one in which it had hibernated. The writer had one spin two new cocoons during the sunmier. Professor Gillette notes that in Colorado the larvae leaving the cocoons in the earh' spring leave those in which they have hibernated and seek other places in which to spin new ones and pupate. He reports that under lU bands placed on the trees in the early spring 6 larvae which w^ere spinning new cocoons were taken. Various reasons might be assigned for this habit of the insect. It might be that the cocoons are too deep in the wood of the trunk of the tree for the moth to emerge without materially injuring itself, or it may be that the larva on becoming active in the spring finds itself in a wet place, and, for either of these or some other reason, migrates to a better place and spins itself a new cocoon. 37 One of Professor Gillette's correspondents reports thut he tound 53 larva' under 295 bands in two weeks. Another reports 307 larva3 April 2 and -1:09 April IT from 2,500 hands. Gillette tliinks that the number caught under these bands is too small to be of any great value as a remedial measure. DURATION OF THE STAGES IX THE COCOOX. On account of the direct influence of this question upon the system of banding, particular care was taken to ascertain the duration of the cocoon stao^e, and especialh' the minimum time. The older writers gave estimates of this time with but little delinite data. Riley gave from 15 to 21 davs; Wash])urn, 3 weeks; Slingerland, 2 to 3 weeks, and Aldrich a])out 1 week. Professor Gillette gives records of com- plete experiments upon this point. In 1900 observations made for him upon lol: larvte gave a minimum of 12 days, a maximum of 29 da3^s, with an average of 20 days. Other experiments directed by the same writer in 1901 on 76 larvae resulted in linding the minimum to l)e 3 da3^s; maximum, 23 days, and average 16f da}^^. In 1900 the writer found that in 7 cages the shortest time varied between 12 and 15 days, with an average minimum of about 14 da3^s. In 19()2 a large series of breeding experiments were carried out, the results of which are incorporated in the following table: Table IY. — Durdtiou of life of the, codling moth inside the cocoon. Date of fiitcTiiiK band. Number of larvfe. Date moths emerged. 1 Number of moths. Time. Total effective tempera- ture. Average effective tempera- ture. 1902. 1902. Ikti/a. °F. °F. J u n e 29 IC, July 19 July 21 2 2 ■ 20 22 433 iiOo 21 2:^ Julv 22 2 23 MS 24 July 11 3.5 July 80 1 16 494 31 Julv 31 4 17 528 31 Aug. 1 5 18 56G 31 Aug. (i 1 23 7-22 31 •July 22 Aug. 9 •) 18 583 32 Aug. 11 i 20 W5 Aug. 29 1 38 1.115 29 Sept. 1 ti 41 1,170 29 Sept. 5 2 4.=> 1.284 29 Sept. 9 2 49 1.392 28 J 111 y 29 Aug. 9 Aug. 11 3 11 3C.2 33 3 13 121 33 Aug. 12 3 H LV-. 32 Aug. 13 (■) ir> 4S1 32 Aug. ir> 5 17 •Vll 32 Aug. It; 2 IS ."SiU") 31 Aug. 18 ."i 20 600 SO Aug. 19 •> 21 til 5 29 Aug. 20 1 2-2 tU^^ 29 Aug. 21 5 tu;i 29 Aug. 22 0 21 ti93 29 Aug. 2f> 2 27 7S3 29 Sept. 9 1 h 1,171 28 July ;u 11 Aug. IS 2 IS 5;i5 30 Aug. 19 1 19 550 29 Aug. 20 1 20 553 2S Aug. 21 1 21 581 28 Aug. 23 3 23 Wl 28 Aug. (J VUiT. IS 1 12 209 17 Auir. 19 1 13 •224 17 Auir. 21 3 l'^ 270 IS Aujr. 22 4 ir. 302 19 Aug. 23 3 17 ;wo 19 88 TV. — Deration of life of the codling moth inside the cocoon — Continued. Date of entering band. Number of larvse. Date moths emerged, Number of moths. Time. Total tempera- ture. Average tempera- ture. Aug. 6. Aug. 13. Aug. 15. Aug. 20. Aug. 22. 1902. Aug. 25 Aug. 26 Aug, 27 Aug. 28 Aug. 29 Aug. 30 Sept. 1 ....do... Sept. 8 do ... Sept. 12 do ... Sept. 17 Days. 392 425 456 485 503 519 558 468 674 604 607 547 633 The number of larvae used was 170, and the stage varied from 11 to 49 days, with a weighted average of 22 days. This average is some- what longer than that se9ured by other observers, and may be partly accounted for by the lateness of the season. The principal point to be clearly shown is the length of the mini- mum stage, which these experiments show to be not less than 10 to 12 days. The time spent in the cocooil l)v the hibernating larva^ varies con- siderabl}^ but usually lasts about eight months. If the larvae are taken inside and kept where the temperature is higher, moths will sometimes emeroe in Januarv or Februarv. INFLUENCE OF TEMPERATURE UPON THE DURATION OF THE STAGE. Various authors have stated at A^arious times that this stage might be considerabl}^ lengthened or .shortened by temperature. Table V shows a preceding table arranged according to the effective tempera- tures and the lengths of time. Table Y. — Effective temperature and length of cocoon stage of codling moth. Average Total Average Total Average Total tempera- tempera- Days. tempera- tempera- Days. tempera- tempera- Days. ture. ture. ture. ture. ture. ture. °r. °F. °F. °F. . °F. OF. 17 209 12 25 604 24 29 1, 284 45 224 13 26 547 21 30 535 18 18 270 15 607 23 600 20 19 302 16 1 674 26 31 494 16 330 17 1 28 553 20 528 17 21 392 19 58 1 21 566 18 425 20 1 641 23 566 18 433 20 1 1,171 42 722 23 558 26 1 1,392 49 32 481 15 22 456 21 29 550 19 511 17 485 22 i 615 21 583 IS 503 23 633 22 645 20 519 24 661 23 455 14 23 505 22 693 24 33 362 11 24 543 633 23 26 783 1,115 27 38 424 13 25 468 19 1,170 41 1 39 From the table we find that the niiiiiinum total temperature is 209^-, the maxhnum 1,31)2 , and the average oi)'2'. The evidence given by this table is insufficient to warrant any definite conclusions. It is quite evident that there are other factors which have not been taken into account, of which moisture and unequal development of the larvte when the cocoon is spun are probably the most important. EFFECT OF THE INSECT UPOX THE FKUIT. The effect of the injury by the codling moth upon the fruit varies with the variety of the fruit and the season of the year in which the in]\uT is done. The attack of the larvae of the first generation usually causes the fruit to fall. A few of the fruits of fall and winter varie- ties, after having been injured, stay on the trees for the remainder of the season, but the early varieties fall quite rapidlv and readily. In all cases the effect of the injury is to cause the fruit to ripen prema- turely. The amount of the windfall of the late varieties depends in great measure upon the amount and violence of the wind. The effect of the injury upon the value of the fruit is variable. If the inside of the fruit is eaten out, it is valueless except for use as cider apples. When the injury consists of only a small defect on the exterior of the fruit, it may be graded as second, and is of considera- ble value. Fruits often bear very small spots where the larvt^ have pierced the skin but have failed to bore into the flesh of the apple. These spots do not materially injure the apple, and many of them are packed as first-class fruit. In cold storage apples which have been injured by the codling moth are the very first to ]>egin to rot, and are consequently sources of contamination to the surrounding fruit. THE PUPA. ^ The pupal stage of the codling moth is that stage in which the organs that are peculiar characteristics of the larva are broken down and worked over into the tissue of the adult. The pupa is about half an inch in length, and varies in color from yellow to brown. (UqxMul- ing upon age, and when the moth is about to emerge it has a distinct bronze color. The head, eyes, mouth parts. antenna\ legs, and wings of the moth are apparent in shcniths which urt^ inunovably attached to the })ody. The a])dominal segments, which are movable, are each armed with two rows of spines, except the ttMiuinal st'gnuMits. wliicii bear only one each. These spines point backward, and play an impor- tant part in the economy of the ins(^ct. The last abdominal segment has a number of long spines with hooks at the end. These hooks are fastened in the silk and aid the pupa in holding its place in the cocoon. EMERGENCE OF THE MOTH. After the })upa has thrust itself out of the cocoon, the pupal skin splits down the back, and the moth forces its way out by splitting 40 awa}^ the head end of the pupal skin. The legs, antennae, and wings are drawn out of their sheaths. The insect is wet, and the bod}^ wall is soft. The wings increase several times in size, and as the body dries it grows more rigid. A few moths were observed to have emerged in the field. During the process of expanding and growing they clung to the bark of the trees with their heads up (PI. VI, fig. 1), avoiding the sunlight. When the wings were fully expanded the moths would often hold them over their backs for a few minutes, in a manner simi- lar to the wa\' a butterfly holds its wings. Af tei.\ running about over the tree for a short time the moths fly into the lower branches of the trees, and are lost to observation. Their quick and erratic flight is similar to that of other moths of this family. The whole process of emergence takes from fifteen to thirty miiuites. THE ADULT INSECT. The adult insect or moth is quite variable in size. The wings expand from 14 to 19 mm. Commonly speaking, they never expand over three-fourths of an inch. The whole insect is covered with scales in varying colors. The tip of the front wings bears a lai-ge dark- brown spot or ocellus on which there are two irregular broken rows of scales, which have a coppery metallic color, and with some reflec- tions of light the}^ appear golden. Near the ocellus there is a very darii-bro«^n band across the wing, which is more or less triangular in outline. The remainder of the wing is crossed by irregular dark and white bands, an appearance caused by the white tips on the dark scales. In many specimens there is a distinct darker band across the wing, while in others this band is not apparent. The hind wings are a grayish-brown color, darker toward the margin, with a long black line at the base of the fringe. The underside of the hind wings has dark, irregular, transverse markings. The underside of the front wings is of a light-brown color, with opalescent reflection and with a few markings except on the costa. The legs and head and patagia are covered with long, narrow, white-tipped scales, while the body is covered with white-colored scales with opalescent reflections. The large white scales on the caudal margin of the abdominal segments are especially conspicuous. (PI. VII.) HOW TO DISTINGUISH THE SEXES. There are many characteristics ])y which the males and females may be easily distinguished. As stated by Zeller, the males have penciled, long, black hairs on the upper side of the hind wings. These hairs are sometimes of a light color, which renders them difiicult to distinguish. Slingerland discovered that the males could also be distinguished by the presence of a distinct elongate, blackish spot on the underside of the fore wings, which spot consists of a number of black scales. These 41 scales are sometimes of a slate color, which under certain lights ren- ders the spot inconspicuous. There is a great difference between the genital organs of the two sexes, as the ovipositor of the female can be said to be hoof-shaped, and ends, roughly speaking, in a point; while the presence of the claspers on the male can be said to cause the abdomen to end in a line. HABITS OF THE MOTH. It is general h^ stated by writers that th(^ adults of the codling moth are but rareh' seen in orchards. In cases where the infestation is not ver}' bad this is usually the case; but where the infestation is bad it is a ver}' common thing to see the moths in the orchard, but never in any large numbers. They spend most of their time resting on the upper surface of the leaves or on the trunks of the trees, where the}' are hidden b}- their resemblance to the grayish l)ark. AVhen disturbed, the}' fly awa}' so quickly that the e3'e is unable to follow them in their erratic flight. According to many observers the codling moth feeds on the juice of ripe apples. The w' riter has often observed them drink- ing water in cages. As the conclusion of man}- investigations 1)}^ many persons and under various conditions, it has been deflniteh' deterndned that the insect is not attracted to lights. A very few records of captures of codling moths at lights, usually of the accidental catching of one or two specimens, have been published. DURATION OF THE LIFE OF THE MOTH. LeBaron gives 1 week as the average length of the life of the adult codling moth, Washburn gives from 10 to 15 days, and Slingerland says that one moth lived in his cages for IT days. Kecords of the writer in August, 11)0*^, of forty -seven moths, show that two moths lived 1 da}^; ten, 2 days; eleven, 3 days; ten, -1 days; two, 5 days; seven. 6 da3^s; one, 7 days; two, S da3'S, and two, !> days; giving a Aveighted average of 1 da3\s. The length of the adidt stage depends upon the conditions under which the moths are kept, as they will live longer if there is water which they can drink. The average of 1 days was obtained when there was no water accessible to the moths; but had there been water or ripe fruit, the average would probably have been longer. GENERATIONS OF THE INSECT. The question of the num])er of generations of the codling moth in one season has for many years been in doubt. In recent years ento- mologists have been stimulated to greater etlorts and have in a measure solved the problem. The economic inq)ortance of this (piestion is very apparent, as the second generation of the insect inflicts about ten 42 times as much damage as the first generation, and it is necessary to know whether a second generation is present in order that the proper measures of control nmy be emplo3^ed. Great biological interest also attaches to this problem, as it affords an excellent opportunity for the study of the effects of different climates on one insect. The term "generation" is used instead of "brood" because it describes more definitely the idea intended. A generation in this con- nection means a number of individuals which pass through certain f^ages at about the same time, having begun in the same stage at the bv inning of anj^ given season. A succeeding generation is the aggre- gate of all the different broods of the individuals of the generation immediatel}^ preceding. A new generation is considered to begin with the egg stage, and continues through all the transformations of the insect until the moth dies. Many authors object to the term " partial generation," but as there is a condition in which, this term can be used with a definite meaning, it may be well to use it. For instance, in some sections of the countr}^ all the insects pass through one genera- tion; a few, becoming more advanced than others, ma}" succeed in passing through the pupal and moth stages and la}' eggs, from which larvae hatch and enter the fruit, whereas the majorit}" of the insects hibernate as larvae and do not transform until the following spring. As those insects which enter the fruit in the fall do not for the most part complete their development, at least in the field, they are termed a partial generation. In tabulating the results of observations in regard to the time of the various stages we find that at certain periods more individuals of a generation are in certain stages than at other times; and likewise we find periods when there are fewer insects of a certain stage than at other times. These periods are designated respectively the maxima and minima of the different generations. It is alwa3's considered that the larvae, pupae, and moths found in the early spring belong to the last generation of the preceding season and may be termed the hiber- nating generation. From the writings of European authors we find that there is but one generation of the codling moth in northern Europe, including England (Westwood) and northern and central Germany, while the evidence of Reaumur and Schmitberger shows that at Vienna and in France there are two generations. American writers have at various times recorded many observations of variations in the number of generations in the United States. Fitch seems to indicate the pres- ence of but one generation, while Harris says a few may transform and enter the fruit in the fall, though the majority of the first generation hibernate. Fletcher reports that careful observations extending over ten years convince him that near Ottawa, Canada, there is but one regular generation of the insect, while in the fruit-growing districts 48 of western Ontario there are two g-enorations, the second })eino- inva- riably the more destructive. The observations of Atkins. Harvey, and Munson ao-ree with those of Harris. Slingerhmd says in 1898 that his observations indicate that in New York a large number of the larvje of the rirst generation develop into moths, the percJMitage transforming depending upon the weather conditions of the season. In 1894 Smith found ))y a series of observations that the larvte col- lected in midsummer did not transform further that y<'ar. but liii)er- nated. Later, in 1897, he states that near New Brunswick, X. J., there is positively only a single annual generation, and. further, that south of Burlington C>ounty there is at least a partial second g(^nerution. In addition to the observations already given of conditions (juite simi- lar to these in New Jersey, we find that Trimble in 1865 carried out a very careful and accurate series of experiments upon the life history of the codling moth at Newark. He found that on August 1<> there were three pupa^ among the insects under observation, and that on August 2() many moths had emerged: on August 23 he found that one in five of the larvae had transformed. Sanderson tinds that there is one generation and a partial second generation in Delaw^irc^ He states that of the larvw found July 31 about 29 transformed and 5 remained as larvte. Taking these numerous observations and the data given in regard to them into consideration, we must conclude that Doctor Smith's observations are too few in numl)er and do not justify the assertion that there is but one generation of the codling moth at New Brunswick. Man}^ observers in widely different sections of the United States have found two generations clearly defined. Le Baron states that '* in the latitude of Chicago a great majority of the moths of this brood (first) emerge the last two weeks in July.*' Riley, after many years of close observation, states that the insect is "invariably two ))rooded in Missouri." Popenoe and ^larlatt found two genera- tions in Kansas. Gillette indicates two generations in Iowa. Walton b}' breeding experiments discovered two generations in the same State. From a series of observations extending over several years, checked hy l)reeding experiments, Cordlev concludes that there are two generations at Corvallis, Greg. Koebele says there are two gen- erations in the Santa ('ruz ^lountains of California, and the insect proba])ly does not ditter in its liai)its tliroughout tlu» State. Based upon one of the most extensive studies of this ([uestion that has ever been made, Gillette arrived at the conclusion that then^ nvo two generations in Colorado. Cooley says that in 19o*i tluMi* wen^ two generations at ^Missoula. ^lont. Forbes indicates a third generation in Illinois, based upon the fact that very young larv;v were found on October 4. Coquillett states that his notes indicate that the insect has three generations in California. Washburn says there are three to four generations at Corvallis, Oreg. Card gives two to four in 44 Nebraska. Cockerell concludes there are three full generations near Mesilla Park, N. Mex. Aldrich in 1900 stated that there were three generations in Idaho, and in 1903 concluded after a series of breeding- experiments that there was a partial third generation at Lewiston. At various times writers have made assertions that in the warmer sections of the United States a partial fourth brood was produced. In carefully sifting all these statements the writer tinds man}^ points which throw doubt upon and render them of but little value, principally because definite dates and localities are not given. The date and exact localities are often t)f as much importance to future workers, and per- haps of more importance, than the o])servation itself. METHODS BY AVIIICH THE NUMBER OF GENERATIONS MAY BE DETERMINED. From the nature of the case the determination of the number of generations of the codling moth is a most diflicult problem to solve accurately. The methods used must be scrutinized carefully, and all possible sources of error must be taken into consideration or elimi- nated. Xhe correctness of a conclusion can be assured only by exact- ness in methods and by corro])orative evidence secured l)y different methods. Observations made in orchard examinations have constituted one of the methods largel}^ followed. Although ol)servations are of great value when used in connection with other methods, they often lead to erroneous conclusions when used alone, as it is possible to obtain evidence of the condition of an orchard onl}- from the study of a veiy small portion of it during a very short period. Past conditions are often unknown, and conclusions obtained are largely based upon pre- conceived ideas. If a large number of insects can be bred throughout the season, much valuable data can be secured and the prol)lem solved beyond an}^ doubt. As 3"et we have no records of breeding experiments carried on throughout the season with the necessary accurate data. The writer has attempted many times to breed the insects throughout the season, but has alwa3\s failed, usually on account of some unfore- seen diflicult}" which caused the experiment to end. However, it is believed that with proper care and experience this breeding can be successfully done. Breeding the insect and harmonizing the results of the breeding b}^ observations in the orchards has been the method most used in working upon this question. By breeding the insect through parts of its generations valual)le data have been secured, which, if pieced together and corroborated by other methods, are almost as valuable as if the insect had been bred throughout the season. Man}" entomologists have neglected to increase the value of their breeding experiments by keeping the insects under conditions of tem= perature and moisture diflerent from those prevailing in the orchard and keeping no record or a very fragmentary record of the tempera- 45 tares to which the insects were siib]'ected. Main' other reconls are questionable by reason of the fact that the t^eneration. or the nearness to the maximum of the generation, of the insects phiced in the cage was uncertain or unknown. Early in his studies of the life liistory of this insect the writer saw the necessity of linding some method by which the numbers of indi- viduals of a generation could l)e approximated at certain times. By an incidental study of the records of larvjv captured under bands, published by Professor Aldrich in lOno. it was noted that at a certain time in the season there were fewer larvie so caught than at i)eriods of time immediately following and preceding. By collecting as many records as were ol)tainable at that time, it was ol)served that these conditions werecjuite constant. The periods of the larger and siualler number were termed, respectively, the maximum and mininuun of larva? entering bands. In 1001 many fruit growers in Idaho, at the recpiest of the writer, kept and submitted records of the larva' killed under bands. Other records, many of which had been made without any idea of the future use to which thev might be put, were collected from many sources. These records were tabulated and curves were drawn upon cross-sec- tion paper, using the time as one factor and the number of larvae as the other. These curves give quite an accurate picture of the course of the insect in the orchards throughout the season. Not all of the records, however, were satisfactory, as a few of them from various causes gave data which were of no value. The curve showing the efl'ective tem- perature at the dates at which the larvc\? were killed under the l)ands was drawn upon the same charts and gives (juite accurately the etlVct of the tenq^erature upon this hai)it of the insect. A number of these records are reproduced (tigs. 5 to IG). INACCl'KACIKS OF THK KKCOKDS. There are many sources of possible inaccuracy in these records. The greatest inaccuracy is probably found in the weekly or biweekly band records, because these are composite records of many individutil trees and show only approximately the dates of the maxima and min- ima, ^lan}' of the records were commenced too late in the season to be of any real value: and when thev were started even a little late the curve ascends with rapidity, which would not have happened had the record been started earlier. In consequence of a series of warm days, the maxinumi number of larva.^ may enter the bands sooner than they w^ould if the tenq^erature had remained normal: and if the tenqxM-ature be low for many days, the maximum might be later than it would be normally. Spraying might seriously interfere with the accuracy of the record, as at certain ])eriods all of the larva^ entering the fruits might l)e killed and thus cause a fall in the curve of larvie entering 46 >'^"" :::::::':::":":::"': i , 1 • • • ' ^ 1 1 J 1 1 ! M ! Jj h^ 1 1 j 1 1 1 ^^.f-Hi ^- -:::::::- 1 M ' ! ! j \] , iTp^' — CV..-- L^^ . J-'-i-rl^I'll' j i r7^ , --:::::::::: ^^ t-fH o-:: ::::::::::::::^::: ^ :: _::::_::;■=;:; ::::::;:::::>q: CO nit INIII'iflr^ >;,!■.;':- •-co;:-:;:::::::::::::::::: HthTlLL ' ' ' ■ ^sn Q.- LU .= :::, = ?::::::::::: :::::i:: :-U!-;::i:|:;:::;::ii>;;; — ---- f^ -i ^..^_l_^,.i-=ri:nr . M i 1 1 1 4- -trTtTTTni^l-'r^idd-Ui Ml 1 1 ^ ? S S 2 o bands. When counted the larv^ were killed, which reduced the number of larva3 of the succeeding generation. If the tree from which the record is taken should be covered with rough bark or have a large number of holes and cracks in it, the number of larvae entering the bands will not be so great as if the band were the only place in which they could hide to spin their cocoons; therefore, filling the holes and scraping away the rough bark would cause a rise in the curve. . In most cases the con- ditions which Avould ren- der the recoi'ds inaccurate were eliminated when it was possible to do so. In order to show the relations between the daily and the weekh" hand records, a weekly summary (fig. 6) was made of Gibson's daily band record. By this means it was shown that the weekly records are only approximate, and show the general trend of the insect in the orchard rather than any details. One writer has suggested that the rise and fall of the temperature would cause a corresponding rise and fall in the number of larv», so as to obscure the true position of the maxi- mum. B}^ a study of the record made by Mr. Gib- son (fig. 5), in which the 47 effective tenipeniture is .shovv^ri hy a dotted line, many inter(^sting facts in regard to the temperature can be observed. It irmst b(; noted, however, that the number of larvje caught on any given day is influ- enced by the temperature of the preceding da}', as most of the larva? enter the bands at night, some time before midnight, and that they are usually killed and counted some time the following morning, while the observations upon the temperature were taken at 0 a. m. Fig. 6. — Weekly summary of Mr. Gibson's band record. and 6 p. m. The great rise which occurred on June 2-i was probably due in a great measure to the fact that the bands were placed upon the trees on the 21st. The fall in the number of larv{i3 on Jime 24, the rise on June 27, the fall on June 30, the rise on July 1 and 2, and the fall on July 4 can be partially accounted for by the corresponding rise and fall of the temj^erature. From about July 5 to August 4 the Fig. 7.— Band record made by William A. George, Caldwell, Idaho. In 1901. temperatuiH^ was liigh, ])ut there was no corresponding rise m the number of larva', as there were no larvje ready to iMiter the bands, the majority of the insects being in the moth, egg, and younger larval stages. This interval of few larvi^ marks the time between the maxima of the generations entering the bands. In the second maxi- mum it can be noted that the rise and fall of the number of larva* is 48 usuall}^ parallel with that of the temperature, but toward the end of the record the temperature has but little influence. The record made by Mr. George (fig-. 7) and Mr. Ayers (figs. 8 and 9) show practically \:^ Fig. 8. — Weekly band record made by Mr. Ayern at Boise, Idaho, in 1897, on 140 tree^. the same conditions, but not so clearl}^, on account of the length of time between the observations. LENGTH OF THE LIFE CYCLE. In order to establish a correct basis for the determination of the number of generations, it is essential that we determine as closely as Fig. 9.— Band record made by Mr. Ayers in 1898. possible the average number of days in which the insect can pass through one generation. Assuming a certain date, with as much accuracy as possible, when the maxima occur in a band record, ana taking into consideration all the imperfections of the records, wo should have approximately in the number of days between these max- Bji. 41 , Div. of Entomology, U. S, Dept. of Agriculture Plate VI. Fig. 1.— Larv/e, Pup/e, and Moths on Rough Bark. Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate VII. Fig. 1.— Codling Moth (Enlarged 4 Times'. Wing on tlie right shows the reflections from the gold-colored scales in the ocellus. Fig. 2.— Codling Moths (Enlarged Twice). Fig. 3.— Codling Moths (Natural Size, from Slingerland\ 49 ima the length of the life cycle of the insect. In the records given we find that tlie pcu'iods vary from 40 to about 00 days, "vvith an aver- age of 55 days, or about 8 weeks. Professor Gillette finds that according to his life history studies upon the sunmier l)rood the JULY AUGUST SEPT. IZ3A'i6 78l0 ir21J4HSi6i7l8«»2ina2i»3U7»»3l|i 2 54 S fcTa?^!!!?!^^ 190 180 XT. 170 ±1 160 T 150 :::::::::::::::::::::"::::::::::; i IM) 130 120 ::::::::::::::::::::::::::::::::/:: ::::: 10 1 I 100 T :: :::::::::::::::::::+:: 1: - 90 I __ / t. 80 70 1 ^^ 60 ? s 50 ^/ 40 T 30 +\ r i^ 20 , / f . ,,-■ 10 - - - -\ - ? ~.- -- ,^ 0 \' := t: . Fig. 11.— Band record publi-^^hed by rrof.C. P.Gillette, taken on 11 trees, at Fort C\>llins.Colo..in IWO. laying stage, 5 days (estimated): total, 49 days, or 7 weeks. From the writer's nunuM-ous records of tlie lengths of the ditferent stages, however, it is found that most iwo somewhat h)nger than those given 6514— No. 41—08 4 50 b}" Professor Gillette and that the egg stage averages about 11 days; from the hatching of larvae to leaving the fruit, 20 days; from enter- ing the bands to emergence of moth, 22 days; from emergence of moth to middle of egg laying (estimated), 5 da3\s; making a total of 58 daj^s, or about 8 weeks. By adding together the shortest times and the longest times, respectivel}^, we find the minimum length of the life cycle to be 36 days and the maximum 100 days. This period of 55 to 58 days having been obtained by these two widely different methods, they are probably not far from the correct average length of the life cycle of the codling moth. SEASONAL HISTORY. By following the development of the codling moth through the sea- son as caref ull}' as possible, we are enabled to throw more light upon the question of the nmnber of generations. Those larvte which have escaped their enemies during the winter, if left in the field, change to 800 600 .•^"•^^n J ,r,J"^^,n J , AUG., ,J „ SEPT, n Oct. =F- :: HI 100 zoo 0 ^ '- : .■ ■. 1 i i i . ; , , 1 . ■ T , , . i , i 1 , , 1 , , , 1 , 1 ., , i , , , ; M ii Fig. 12.— Band record made by Prof, E. A. Popenoe, Manhattan, Kans., in 1890. pupas, according to Slingerland, just prior to the time when the apple trees are in bloom. He found the first pupae April 27, and hy the Tth of May about one-fourth had j^upated. In 1902 the writer found the largest number of pupae about the time the apples were in bloom. Some were found in rotten wood as late as June 10. The location of the larva has the greatest influence upon the period of pupation, those in warmer places pupating more quickly than those in colder situations. EMERGENCE OF THE MOTH. From the records of various writers, as compiled by Gillette, we find that the first moths appeared from April 21: in New Mexico to about May 16 at Corvallis, Oreg. Mr. McPherson records that in 1901 he found a moth in the field in Idaho as early as April 23, and that the moths were most numerous about May 1. Mr. Hitt in breeding 50 moths found that the first emerged May 5 and the last May 28. In 1902 the writer found that the majority of the moths emerged between 51 May 15 and 20. Cordley states that in Orei^on in 1899 moths emerged in some cases April 10, and continued to do so until July 1. At Ithaca, N. Y., Slingerland found in 1896 that moths emerged from May 3 to June 22, and in 1897 from May 21 to June T. Gillette records that he found moths out of doors at Fort Collins as early as April 26. The extreme range in time of appearance of these moths was 69 days in their cages. At Fort Collins, ac- cording to Mr. Hitt's records, this period extends over about 23 days. Professor Slingei'- land found that this range was 49 days in 1896. RELATION BETWEEN EMER- GENCE OF THE MOTH AND THE BLOOMING PERIOD. Slingerland states that the moths begin to emerge in New York about the time the apples are in l)loom, l)ut the majority do not emerge until after the blossoms fall, and but few lar- vie are found to enter the fruit until about two weeks there- after. Gillette found the first moth emerging about 10 days before the trees were in bloom. He states that the majority of them emerged about the time of bloom, but eggs were found July 9, 1900, and June 19, 1901, and were all hatched by July 21, the trees having been in blo;gsom about May 5 to IT). This would make about a month between the ])looming period and the time when the S § S g s o o O o o o -HttH— m:. : .::; ■U— .-^ :.;: .!:|( -1-4-*—^-^- o z > < F=^ ZZ^ ■4''-i:4-i li::;.!;: = - : ji ,. : : : -: :::::; ^^::nTr "TTTTrTTT ^tr-i— T :zz^.'--- =^^~— ^rtrr=r '" M ^i4rt— : : 7 r/:; ::rvr • ;■;:; ■ ■ — Tt 1 ■ r ■ ; i ■ i i ;!;;;■■ M ii:! - . :- :: -:i~ -i-x^- .2 - - - ' ■ " : C_i : Z - __ ___ — _ [ ' 1 m - — - — — — o A : ' ' ■ ■ ^^ 'X —\— ^ - ""^ :: ' 1 ■: " ■ :■ 1 i ^^ ^_ d p " = -^=^ . ! . . ■ <-^ Ci c Pj : I . i •• J3 : - - , : 1 ■ ' ■ ' ' ■ 1 ' , E : '■'!■■ ■ -I'l t " •c* : 1 ' • 1 j_ — ^ — — i 1 "i. : ^ / J^ — '- - r__/- : ■ , : .i; ' ' : : ■ (A m o o < 5^ : — jrrr:- _- ::_:. ^ - 5 <^ - g : t t L i •liiii - i i i i 1 . i ' - 52 first larva? hatch and enter the fruit. Card found the eocrs about three weeks after the blossoms had fallen. Cordle}" found that in 1898 the first larva entered the fruit about Jul}^ 1, the egg from Avhich JULY AUGUST 1 SEPT. 1 1 2 Si '5 6 7891011 2 5'-'il6i7l9l')202l?r32«W627J8S3!)5l 1 2 5 2.'; 6 7 8'5l0ill2i5HI'>l6l7l8RM2l222J247i2627J8213Obl|l 2 3','; 6 78')l0in2l5l'.l'il6i7iBiO202l22232'.2b273a3c|l 2 Zi, OCT. '567890121 ','>6 2600 T I ' 2500 2AO0 T 2300 I 1 2200 , T 2100 i 2000 1900 1800 Ta 1700 ,-' ^ T 1600 J \ T 1500 / T 1 lAOO / \ 1300 ^ 1200 / ^ ilOO \ 1000 7 ^ T 900 1 \ 800 / '« 700 L \ 600 ; ^ 500 J s. , AOO V --=, -~,^ 3O0 I I "^^- ::;:::: 200 "^s^ ^-^ 100 /"""" '"---- '■ 0 , -. I - J- 1 1 Fig. 14.— Band record made by Prof. J. M. Aldrich, Juliaetta, Idaho, on 40 trees, in 1899. it hatched having- probably been deposited about June 21. This enter- ing of the fruit took place about two months after the petals had fallen. The writer found that in southern Idaho in 1902 the apples were i»i full bloom about May 13, and the first larvae were noted to Fig. 15.— One of the records made by H. E. Burke at Boise, Idaho, in 1902, to determine the maximum of the second generation. have entered the fruit June 11, or about 25 days after the blossoms had fallen. From these few observations we find that the moths ma^^ emerge some tim^e before the apples are in bloom, and, depending largely upon localit}^, the larva; he^iii to enter the; t'luit from a week to two months after the blossoms have fallen. From the standpoint of the orchardist this is a most important cjuestion in considering the effect of the fii'st sprayino- upon the insc^ct. JULY AUGUST SEPT. 1 ??A^b79?lO ii2ijiuiibi7ai9J(l?l5523X»?b5728»MJii 25'r5b?89lOiii2iJi<.i')ibi7i9i920?i2a»?^2(>?72S?J303i i 25'f'i6 7S'5l0iii2i}i4isi6i7i8i- — ^ 28 ,/_^,._.\, . ../..._ ^ ^:.._.A- -...\..n.- 2<' ,i-- \ 1 ^ J / . U \(-L 2^ .' ^^ \ 7 "" '"/ ~'V ^ "7 22 ": "" ":'::::::is ^ "7 ; 7 : """ 7 7 — 20 ^ ;, / /. /; ., ,/ ^/ 18 ^S..T ..^ / / / 'i._ . ,." 16 0 s_._._/_ ,::/ \._.__^y_____ 14 ^Js S '' / .? \ / 12 s^ \y /y / 0 8 6 4 2 0 ::: ::._: t Fig. 16.— Record by H. C. Close, Utah Agricultural College. The next point at which we can make any definite ohservations upon the codlino- moth is when the larvje are leaving- the fruit and entering the bands for the purpose of spiimino- their cocoons. The band rec- ords g'ive this most valua))le data in a very accurate manner. The following table shows the maxinuim of the ditle rent o-cnerat ions enter- ino- the bands, according to these records: Table VI. — yU(xhimi\i of larriv hilled under Jxnidii. Year. 1897 1898 1899 1901 1901 1901 1901 1901 1901 1901 1901 1901 1901 1899 1890 1883 Locality, Observer or source of record. Mr. Ayers do rrof.J.M.Aldrich ir. (}. (Jibson J. Shearer do Boise, Idaho do .luliaetta, Idalio Nampa, Idalio.. Pavette, Idaho . do do do I'rovo, rtah Itah Agricultural I College. do do do do Hagernian, Idaho I K. E. Conuor Lewistou. Idalio.. ' S. (!. lasmau Caldwell, Idaho.. Win. C. (ieorge ... Colorado David Ihothers... Kansas I K. A. Poponoe San Jose, Cal (Miapiu First maxi- mum. 110 Julv 17 110 .lulv 10 10 .luly 20 4 .lune 2(i 3 Julv 18 80 Julv 1 1-28 July r> 23 do ... 2(i July 13 31 Julv 5 27 1 Julv 12 4 ....do... lOl June 25 I Julv U5 ....I July 25 8.50 July 19 Second maxi- mum. Sept. 15 Sept. 10 Sept. 24 Aug. It; Aug. 17 Aug. 30 do ... Sept. 2 Aug. 27 Sept. 2 Sept. 4 Sept. 10 Aug. 13 Sept. 15 Sept. 28 Sept. 23 "I Time of re- moval of bunds. 4()7 Dailv 215, Weeklv... 3,;554' do.... l.WK) do.... 4,141 do.... h 6112,247 Weoklv.... r)2 20.909 do' (U> 8, 020 do ' 87.48 149. 36 215. 50 116. 75 1 71.tk5 ! 44.4'i I 13.2 ISO 45' 2. 829 do 108. 2 50: 2,.S80 do 84.7 54 194 do 8.2 60 {\^\^^ 6permontli 166. 6 49 IvtO 2 to 5 drtvs 61 Weekly.'. 66 do ... ..do.. 64 54 Riley states that the larvre of the first generation are most abundant about Jul}" 8; Gillette, that this occurs in Grand Junction about July 15, at Denver July 21, and at Fort Collins Juh^ 25. MOTHS OF THE FIRST GENERATION. Card found the first moths of this generation about July 2. Cord- ley gives August 1 as the date for the first and September 15 for the last. Gillette gives the following data: Grand Junction, Colo., first Juh^ 28, last September 12; Can3"on City, first Juh^ 15, last Septem- ber 10; Fort Collins, first Juh^ 13, last September 12. According to Gillette, the eggs of the first generation were most abundant August 12. In 1901 the writer found eggs most abundant between July 15 and August 4. In 1902 the}^ were most abundant about the same time, but were obtained in cages as late as August 29. The dates of the maxima of this generation of the larvfe going under bands is well shown in Table VI for the second generation. An examination of these band records as published shows that the period of the larvie leaving the fruit and entering the bands extends over two mouths. HIBERNATION. The following table by Gillette shows the time at which pupation ceased and the larvae began to hibernate at various places in Colorado. It was found, as shown b}^ the table, that pupation ceased between August 10 and August 30, var^dng with the localit}' in wliich the experiments were made. Table VII. — Proportion of Idhcrnating larvx taken at diferent dates. Locality. Dates larvfc Avere taken. Number taken. Number hibernat- ing. Record ])y— Grand Junctiou Colo July lG-23 1900 33 53 60 1 3 8 Silmon Smitb Do Julv 24-30, 1900 Do. Do July 31-Aug. 6, 19U0 Do. Do.... Aug. 6-13, 1900 Do. Do. Aug. 13-20, 1900 79 130 192 22 14 51 66 115 80 25 70 50 100 78 130 192 5 4 14 56 115 80 0 30 44 99 Do. Do Aiig. 21-29, 1900 Do. Do Aug. 30-Sept. 4, 1900 Do. Rockvford Colo Aug. 1-6 1900 H.H. Griffin. Do Aug. 7-11 1900 Do. Do Aug l''-14 1900 Do Do Aug. 15-21, 1900 Do. Do Aug. 22-28, 1900 Do. Do Aug. 29-Sept. 0, 1900 Do. July 30,1899 Dr. R. J.Peare. bo ". Aug. 1-13. 1899 Do. Do. Aug. 14-20, 1899 Do. Do Aug. 21-28, 1899 Do. Cordley has for several years been unable to breed any moths after September 15. In 1900 the writer found that pupation had ceased September 1, and in 1901 September T. In 1902 more extensive breed- ing experiments were carried out, from which it was found that pupa- tion began to grow less about August 1 and entirely ceased August 22, and that no moths emerged after September 17. 55 At various times records have been made of finding single moths late in the season, in October. The presence of these moths can be easily accounted for by the fact that the larvie probably got into some place where the general outside temperature had no effect on them, and increased temperature caused transformation. EVIDENCES OF A THIRD GENERATION. It is often found that in September a large number of the fruits have been entered by very 3'oung insects, and it is also found that in some localities these injuries extend into October. This has given rise to the belief that there is a third generation present: and not having definite records in regard to the life histor}' of the codling moth, many fruit growers have come to the conclusion that there are three gener- ations, and some have even gone so far as to say that there is a par- tial fourth generation. Many entomologists have taken these state- ments from the fruit growers, and not having given as complete study to the subject as was possible, have published the conclusion that three generations were present. The writer has collected all of the publi- cations in which three generations were either indicated or given as occurring, and has, with the greatest of care, studied the observations upon which the conclusions were based. ]Many entomologists have submitted original notes or copies of the notes from which their con- clusions were drawn. After carefully studying all these records and published accounts the conclusion was reached that there were only two publications in which any substantial evidence is given as to the existence of a third generation of the codling moth. Professor Cock- erell, in a bulletin of the New Mexico Experiment Station, concludes that there are three generations and a partial fourth. Professor Cock- erell relied mainh^ upon observations, and checked these observations bv breeding experiments in only a few instances. The observations, while of value, give the conditions in the orchard at irregular inter- vals, and then only for a very short period of time. ^Nlany erroneous conclusions were drawn from these observations. For instance, the finding of an empty pupa case on ,Iune i^il was considered an evi- dence that the moths of the first generation had emerged. In view of the fact that Professor Gillette finds that the extreme ])eriod of emer- gence of the moths in the spring is 69 days at Fort Collins, and that Professor Slingerland found moth in New York as late as June '2'2. we see that there is the greatest probability that these moths were the latter part of the hiluM-nating generation, instead of the first part of the first generation. The finding of wormy a]i}iles on July o was con- sidered as the beginning of the second generation entering the fruit. On August 12 small larMv in fruit were considered to be the l)eginning of the third generation. Anyone familiar with the conditions of Western orchards knows that small larvie entering the fruit can be 56 found almost any time in the summer. From the evidence ^iven by Professor Cocker ell the writer is of the opinion that there are only two generations of the insect present in Mesilla Park, and that there is no sufficient evidence of a third. Professor Aldrich in a recent bulletin states that, in his opinion, there is at least a partial third brood at Lewiston, Idaho. This con- clusion is arrived at as a result of some ver}^ careful 1}^ conducted experiments which give evidence, by breeding records, which up to a certain point is indisputable. By caging the insects at proper inter- vals Professor Aldrich obtained moths of the second generation on September 3 and 4. There is no doubt in the mind of the writer that these were moths of the second generation. But Professor Aldrich failed to state whether or not he obtained eggs from these moths, and instead of doing so took unknown field conditions to carry out the remainder of his experiments, taking it for granted that the larvae entering after September 6 hatched from eggs which had been laid b}^ moths of a similar age to those emerging September 3 and 4. As the latter were of the A^ery earliest of the second gen::T.tion, there is no reason for assuming that the larva? which entered after this time were not larvae of the retarded portion of the second generation. B}" using the length of the life cycle with the data given it is obvious that these larvae belong to the second generation instead of a third. CONCLUSION. By taking into consideration the evidence which has been derived from the band records, from breeding experiments, and observation, the writer has no hesitancy in concluding that there are but two gen- erations of the codling moth in the arid sections of the West, and that it remains to be proven that even a partial third generation of the insect is present in an}^ part of the United States. The writer admits, however, the possibilit}^ of a partial third generation in the West and South, and that careful, accurate work in the future will give us bet- ter evidence upon this point and settle the question beyond a doubt. By a careful stud}- of the temperatures for several 3'ears in the locali- ties where observations have been made upon the number of genera- tions of the insect, the writer hoped to be able to give the total temperature at which the difierent conditions in regard to the genera- tions might occur; but after a great amount of labor this Ayas found to be impracticable, principally on account of insufficient accurate observations upon the insect, and it was decided to make use of the more general life zones in determining the distribution of genera- tions. It may be stated that the boundaries between these life zones are onh^ approximate; that there are difierent gradations between them, and that as jet there are many inaccuracies in the map. Mr. Marlatt, from personal experience and the observations of other ento- 57 mologists. arrived at the conclusion that there was one generation of the insect in the transition zone, two in the upper austral, and three in the lower austral. B}^ using the conclusions of recent years the writei finds that there is one generation in the tran>ition zone, with often a partial second, two generations in the upper austral, and two in the lower austral, with a possibility of a partial third. NATURAL CONDITIONS WHICH TEND TO DECREASE NUMBERS. It has often been noted that a >udden fall of temperature is fatal to a laro*e number of the smaller larva* of the codlincr moth. It has been already noted that Professor Aldrich has recorded such an obser- vation. Hot sunshine and extreme dryness cause many of the pupie in the case to die. A moist climate aids fungi and bacteria to such an extent that sometimes most of the larva? are killed by them. Larva^ that are killed by fungous diseases are hard and mummified, and have a whitish appearance. Bacteria cause the internal organs to dis- integrate and the larva to become limp and full of juices of a brown color. NATURAL ENEMIES. Although the codling moth has many natural enemies, the number as compared with those of other Lepidopterous larvae is comparatively small. This may be accounted for ])v the fact that the insect through- out the greater ])art of its life is more or less protected, but when the larvte have left the fruits and are seeking places in which to spin their cocoons and when in the winged stage they are attacked by numer- ous enemies. Birds are ])y far the most efficient natural enemies of this insect. Anyone who tries to collect the larvjv from the trunks of trees in spring will find very few specimens, but, on the other hand, will Hnd many empty cocoons. The writer has many times in the spring searched persistently for larvie in the rough bark and the more exposed cracks, but found practically none, although many could be secured by cutting into the holes and cracks of the tree. Kiley, Walsh, and Slingerland also note this effectiveness, and the amount of good the birds do can only be estimated. The cocoons are always found, and on a close inspection of the bark a telltale hole discloses the story of some woodpecker's work. It has often been noted also that the same birds have made holes or enlarged the cracks in tlu^ stubs of old branches for tlu^ purpose of digging out the lar\"a\ IMate \'III. figs. 1. -2, 3, shows stubs of branches from an old orchard mwv Klkton, ]\ld., in which these birds have done t^tliciiMit work in reducing the number of larva> during the spring. Fig. '2 is especially interesting, as on close examination it shows the following points: Some time in 1900, in the course of pruning the orchard a branch was cut away, leaving the stub, which is s incluvs long. In the foUov^ino- winter and 58 spring the stub began to crack and decay and the bark to loosen. Many codling-moth larvae crawled under the bark in the fall of 1901. The woodpeckers found this stub in the following winter and spring, and not only probably secured all the larvfe which were under the bark, but enlarged one of the main cracks in order to get those which were hidden inside. In the fall of 1902 all the bark had fallen from this stub and man}^ more larvae took refuge in the cracks. Upon examination, in May, 1903, the writer found that the crack had been recently enlarged, as is well shown in the reproduction. This recent enlarging was probably done mostly by the pileated woodpecker {Ceoplielus pileatus)^ as the chips broken out were quite large, and probabh^ required more strength than other smaller woodpeckers could muster. This stub was sawed from the tree and sent to the writer, and in the latter part of May the moths emerged, and 28 empty pupal skins were found on June 25. The writer estimates that fully 100 larvffi hibernated in this stub. It is highl}^ probable that all woodpeckers feed on the codling moth larvae. Other birds, including the nuthatches, black-capped titmice, wrens, bluebirds, crows, blackbirds, kingbirds, swallows, sparrows, chickadees, and ja3^s, may also feed upon the codling moth, especially those birds which winter in the locality where the larvae are present. Without doubt the bobwhite quail, which has been introduced into many sections of the West, also feeds upon this insect. At best our knowledge of the food habits of manj^ of these birds in regard to the codling moth is based upon but little direct evidence; but reasoning from what we do know positively, there is little doubt that codling moths form a part of the diet of at least some of these birds. Not many years ago a movement was set on foot in the Pacific northwest to import the German kohlmeisen into this country, as it was said to feed largely upon the larvae of the codling moth; but because the bene- fits derived from the bird in its native home were not clearh^ proven, and that it sometimes injured fruit, and also on account of man}^ dis- astrous experiences in the importation of ])irds and mammals which have already been made, the majority of the authorities were con- vinced that it would be a dangerous experiment, and no further action was taken. The expenditure of time and money necessary to carry out such a project would probabl}^ be more beneficial if applied to the protection of our native birds. Koebele writes that in California he knows of man}^ small bats fly- ing around the apple trees in the evening, taking moths on the wing, and even darting down to take moths which were upon the leaves. The writer has often noticed bats flying about the apple trees, but was unable to obtain any evidence that they were catching codling moths. 59 INVERTEBRATE ENEMIES. The writer has often found moths in limb cages dead with spiders silk wound around them, but made no further observations. The insect enemies of the codling moth are either predaceous or parasitic, and are quite numerous as to species, but are usualh' few as to individ- uals. A large number of predaceous insects in the larval stage have been observed feeding upon the codling moth, the following list being compiled from publications of various authors: CJiauUognathus pennsyhanicus. Pterostic/iu.i califomiciis. CJiauliognathus marginatus. Calallnus rufipes. Telephorus hilineatus. Derinestid. Trogosita cortlcaUs. Clerid. Trogrmta lai'icoUis. Chrysopa, Trogoderma tarsalis. Raphidid. Perim egato m a va riegata . In regard to many of these predaceous insects it is doubtful whether they feed upon the living codling moth larva or upon dead specimens. At best, thev do not reduce the number of the larva:* to any consider- able extent. In Utah a species of Annnophila was found stocking its burrows with larva? of the codling moth. It i> also recorded in Cali- fornia that Sphecius nevadetisis was found pulling the larvic out of their burrows. Man}' observers have found the Qg\i> parasitized by a species of Trichogramma. Even in its protected life the larva is preved upon by many parasitic insects, among which are the following: Goniozus sp. P'unpla aunulipe^s. Macrocentrus delicatus. Bethi/lus pp. The writer found traces of three species of parasitic Ilymenoptera which were preying upon the codling moth in the Pacitic northwest, but was unable to breed any of them. Among the Diptera only one para- site is mentioned, namely. IlypoKtena var'uib'dt^ In general it may be said that these parasitic insects are found in such numbers to be of vahu* oidy in neglected orchards, and in an}' orchard that is well taken care of. sprayeil. banded, and otherwise treated in preventi\-e and remedial wa\^. these predaceous and para- sitic insects are found in very small numbers or are entirely absent. Even with the host of enemies arraved aufainst it, the codlino* moth under normal conditions in the West will ruin practically all of the appl(* crop, and if success is to be ()l)tained i)roper measures of con- trol by human agencies must be instituted, and the parasitic and pre- daceous enemie.s left out of the ([uestion, except woodpeckers, which may be encouraged with protit. 60 HOW TO COMBAT THE INSECT. The codling moth seems to have been present and injurious in orchards for centuries, but until about eighty ^^ears ago no one seems to have made any suggestions as to how its ravages might be checked. It would require volumes to contain all that has been written about the methods which have been used against this insect — most of them value- less. Before considering methods of combating the insect there are several points w^hich must be discussed. Many of the Western States have horticultural laws which aim at extermination, and man}^ of the corps of inspectors are working with that end in view; others, however, from recent experience have been led to change their views upon the subject. When one discusses the extermination of an insect he ventures upon debatable ground. As j^et no insect has been exterminated through the agenc3^of man, and judg- ing from past experiences the writer believes that it is impossible to exterminate the codling moth even in a single orchard. The control of it, by means b}^ which the damage it inflicts is reduced to a minimum, is the verj^ best that we can expect to accomplish. It is a prime neces- sity, in order to make recommendations of value, that the entomologist have an accurate knowledge of the life historj^of an insect. Not only is this necessary for the entomologist, but it is essential for the fruit grower also to understand it, in order that he ma}" apply recommen- dations intelligentl}" and vary them to suit conditions. The erroneous ideas some fruit growers have upon the life history of the codling moth are sometimes startling, following recommendations simpl}" because they are given to them, and having no idea of the reason therefor. Often they obtain good results, but more often failures result; and as they do not understand the reasons for the recommendations, they are at a loss to know why they did not obtain good results. To combat the insect successfully the fruit grower must be familiar with all the stages of the insect, the sequence of the stages, where found, and hab- its and variations. He should also be informed how the preventive and remedial measures act in reducing the numbers of the insects. With this knowledge he will be able to vary the recommended preventive or remedial measures to exactly fit his local conditions, and if any failures occur he will in a measure be able to tell why they occur, and the fol- lowing year the experience will aid him in changing his methods in order to obtain better results. He will also be protected against using methods which are of no value, and will thus avoid a large unnecessar}^ expense. PREVENTIVE MEASURES. Preventive measures are those which not only aid in controlling the codling moth, but aid the fruit grower in training trees so as to bear more fruit, support it while growing, and produce fruit of a better 61 quality, size, and color. Although many of these questions are not closely allied to the control of the codling niotii. they are of impor- tance, as anything which increases the margin of profit aids in secur- ing better general results from an orchard. There are many methods of prevention which may he applied to keeping the insect out of a section of t-he country in which it is not yet present. By study of the means of its spread it will be learned how it ma}' have entered the country, and by closing all possible ave- nues of introduction immunity may be secured for many years: but if fruit is being continually shipped into a new country from an infested district, it is only a question of a few years when in spite of all that can i)e done the insect will gain a foothold. Whether it becomes injurious or the loss is nominal will depend upon many condi- tions. Many orchardists who have planted young orchards in infested districts are quite desirous of keeping the codling moth out of their orchards as long as possible, but if there are infested orchards near by this is a practical impossibility. It may be said that money and labor spent in keeping the insect out of a section or an orchard will accom- plish more good if directed toward the study of better orchard methods and adapting the measures of control to that section of the country. To insure the best results in the planting of a young orchard in an infested locality the codling moth should be considered from the very first, and everything that is done should be done only after taking into account the actual or probable presence of the insect. If note is taken of these methods and they are faithfully carried out. a great amount of labor and loss will be saved when the orchard is in bearing. There are manv questions which can be decided for each locality only after all the conditions over which the fruit grower has no control, such as transportation, exposure, temperature limits, and proximity to water, have been fully considered. Although the question of soils is veiy important, by appropriate methods the character of some soils can be materially changed, as by cultivation, cover crops, and other means. The first question which confronts a man wishing to plant an orchard is the question of varieties, which is one of the most diflicult problems to be solved. The soil, the climate, the purpose for which apples are grown, and various other factors, must be considered, each one having its own bearing upon the problem. If a home orchard, the likes and dislikes of the grower are the first consideration, but if the aim is to plant and maintain a ronunercial orchard, the question of varieties nuist be determined, tirst. by finding what varieties are well adapted to the locality in question. This can be learned by consulting the experiment station officials in the difierent States and from the experience of growers who have orchards in that locality. The next consideration is what varieties will meet the market demands and com- 62 mand the highest prices. It is a well-known fact that in the arid regions of the Pacific Northwest the Jonathan, Grimes Golden, Kome Beaut}^ Ben Davis, Winesap, and a few others are the best adapted to a commercial orchard; while in the humid sections of the same region the Newtown Pippin, Spitzenberg, and a few others have proven most successf al. It might be well to note here, as has been stated before, that the Pewaukee and Ortley apples are always found worst infested with the codling moth, w hile the Law^^^er and Winesap are least infested. After it has been decided which varieties to plant, the next question is that of buying the stock. Good stock should always be insisted upon, and one can be sure of securing the desired varieties only by buying from well-established, conscientious nurserjmien. It is preferable in the arid region of the Northwest to plant 1-year-old stock. The land usualh^ has some vegetation upon it, such as sage brush or timber, and after clearing it the soil should be thoroughly pulverized. If irrigation is intended, the ground should be leveled and graded to facilitate irrigation. The courses of the irrigation ditches should be determined by the general contour of the land, tak- ing into consideration the future routes of the spraying machine, which wnll draw upon these ditches for water for spraying. SETTING THE TKEES. There are many methods which ma}^ be used for setting the trees, the details depending on the size of the orchard and the means at hand. The essential feature of the operation is to make the holes large enough to receive the roots of the tree, so that thej^ can still retain their natural position. After filling and packing earth into the holes, water should be allowed to run in, to aid in giving the trees a good start. It has been found that it is a ver}^ injurious practice to place any manure in the holes when the tree is planted. If manure is to be applied in the new orchard, the best method is to scatter it over the surface of the ground. Care should be taken to cause the trees to lean toward the south- west, from which the hottest ra} s of the sun come. B}^ doing so, sun scald will in a great measure be avoided. After sun scald the bark breaks, and the wood is exposed and becomes cracked and decayed. It has often been found that trees thus afi'ected ahva3^s bear a larger percentage of wormy apples than trees on which the bark is unbroken. This is accounted for by the fact that the codling moth larvae go into the cracks to spin their cocoons and are there secure from their enemies. It is a common sight in all sections of the countr}^ to see trees planted from 16 to 18 feet apart, with the upper branches intermin- 63 gling so as to form a dense mass of branches which can not be sprayed properly, and there is no room between the rows for wagons or culti- vators. It is strongly urged that the trees be set not closer than 30 feet apart; some growers pref(u- 40 feet. PRUNING. No arbitrary rules can be made for pruning on account of the fact that every kind of tree and plant, in fact ever}^ individual, presents its own peculiar problem; but there is an ideal which the pruner should endeavor to attain. It is found in many sections of the West that the trees have been allowed to fork so that there are two or three main branches, and upon bearing a heavy crop these branches have split apart, sometimes totally ruining the tree. At best, if the branches are brought back into place and held by bolts, wires, or ropes, a crack will be left, into which fungous diseases can enter and in which codling moth larva? will spin their cocoons. Such a break should be dressed with grafting wax or shellac varnish, and the branches fastened closely together. With proper pruning, when the head of the tree is being formed, this trouble may be avoided. Instead of two or three main branches, the head of the tree should be so formed as to have four to six, thus distributing the weight, and preventing breakage under ordinary conditions. Many apple growers have headed their trees too high for best results. The disadvantages of this method are that it is difficult to reach the fruit and foliage with spra}^, and much more difficult and expensive to harvest the fruit. Other growers have headed their trees so low that the branches spread and droop so that the}^ are close to the ground. In many instances when there is a heavj^ crop of fruit these branches bend down and either touch or lie upon the ground. The result is that much of the fruit on the interior of these trees and on the under sides of the outer branches is so shaded by the foliage that the sunlight can not reach it, and a large percentage will bo poorly colored and of second qualit3\ (See PI. IX.) A mean between this high and low heading is to be desired, which will do away with most of the disadvantages of these extreme methods. In order to secure proper coloring in fruits on trees it is necessary that enough smaller branches be removed to admit an alnind-mce of sunlight through the tops. In the arid sections of the Far West the trees grow with great rapid- it} , and if allowed to take their natural course become slender and not strong enough to support a normal weight of fruit. It has been found that by cutting back half of each year's growth the trees will bo made to grow heavier and stockier, and thus be able to support the weight of a large load of fruit without any danger of breaking. 64 IRRIGATION. Proper irrigation of the orchard depends entirely upon the condi- tions. There are several methods of emplo} ing water in irrigation— b}^ flooding, b}^ a system of checks, or by furrows. The latter is probably the most efficient, but care should be taken that both sides of the tree receive an equal suppl}^ of water. SOIL OR COVER CROPS. The soil of different localities varies, and the treatment should var}^ with the conditions. In irrigated sections the soil is usually lacking in humus, and is often packed so closely together that it is impervious to water. By proper tillage this is corrected to some extent, but the greatest success has been attained b}^ growing cover crops. Red clover is successfully used for this purpose, and is advantageous in many ways. The roots penetrate deeph^ into the soil, thus forming passages for water; by keeping a cover of clover over the soil, evaporation from the soil is retarded, and the irrigation need not be so frequent, as the water is retained for a longer time; the clover can be cut and used for hay; and about every third year the practice of ploAving the clover is followed, so that, in addition to the fixing of nitrogen b}' the roots of the clover, the decaying vegetation adds needed humus to the soil. ORCHARD IN BEARING. A veiy serious error is made b}^ many fruit growers in regard to the first crop of fruit. Reasoning that the first crop is not worth tiTing to save from the codling moth, the grower allows the insect to infest most of it, intending the following year to appl}^ preventive and remedial measures and put it under control. The result usually is that the following 3^ear he has an abundance of insects, and his loss will be considerable. If, when the larva? were all in this first crop, the apples had been destroyed by being picked and buried, or if bands had been used late in the summer, a large percentage of the loss in the second 3^ear could have been prevented. It is often the case that on account of some imforeseen condition, such as a freeze or a frost, the fruit crop is reduced to almost nothing. Under such conditions each grower must decide for himself what methods he will pursue. Usually in such j'^ears the price of fruit is very high, tempting the grower to produce all the fruit he can, even if infested. The writer recommends that when the crop is so small that each tree will produce onlv about one box or less of good fruit, the fruit should be picked and destroyed, not earlier than the middle of July nor later than the middle of August, and other methods such as banding should be used to destro}^ as man}" of the remaining insects as possible. Various instances have been under the observation of the writer Jo which these suggestions were followed with great success. Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate VIII. .^y^ ■'*"^ -■'^^^^^ ' v":- jdflBEL Lt'''fcll i ' ' . i jdflE^ulk'' -j^yVt *1 HA^ngB^ ^i^^l. Fig. 2. Stubs of Branch Cut from a Tree, Showing Work of Woodpecker. Fig. 3.— Stub about 8 Inches Long, Showing Work of Codling Moth Larv/e and Woodpecker. Twcnty-riKlit mollis which tlu" woodpi-i'kiTs did not grt onuTgcd irom this pioi'O of wood. STUBS OF BRANCHES FROM AN OLD ORCHARD NEAR ELKTON, MD. Bui. 41 , Div. of Entomology, U. S. Dept. of Agriculture. Plate IX. 65 There are many preventive* measures which may be applied to the orchard when it is in bearing. It is a well-known fact that an orchard which produces a niodei*ate crop each year is much more profitable than one which produces an abnormally large crop one season and a very small one the next. B}' thinning each year this alternation may be prevented to some extent. The writer is very strongly of the opinion that if thinning is done when the larva? of the lirst generation are in the fruit, and the fruit and \mvx destroyed, the advantages thereby gained are sufficient to compensate for the expense of thinning. It is easy to see how the destruction of part of the tirst generation will prevent much of the injury due to the second genei*ation, which is about ten times that by the tirst generation. It is difficult for the orchardist to determine by observing the entrance holes about what time the insects are inside the fruit. In thinning, all terminal clusters should be reduced to one fruit, and none should be allowed to "grow closer together than from 4 to ♦> inches. During the process of thin- ning, with but little increased expenditure of time or money, the wormy fruits can be removed and the perfect left on the tree. Throughout the season a large number of fruits will drop from the tree to the ground. Upon examination it will be foimd that under normal conditions the larger percentage of these are the result of the work of the codling moth. The percentage varies, however, with many conditions. If a tree is heavily loaded, a large number of good fruits will be pushed off hy those adjoining, and the wind will cause many to fall. The quantity of windfalls increases throughout the season. The percentage of the larvte to be found inside the wormy fruit varies with the time of the year. In the Pacitic Northwest the latter part of June and the tirst part of July and the latter part of August are the times when the largest number of larva' are found inside the wormy windfalls. In a small orchard these windfalls can be destroyed by allowing hogs to run at large in the orchard and eat the fallen apples: or the windfalls may be picked u\) every few days and either made into cider or destroyed. In a large commercial orchard, however, it is not probable that the expense of keeping the ground clear of windfalls would ))e justitied ))y the benetits derived, although such ])enetits would undoubtedly be great. rKKPAHINC FlUIT FOR TlIK MAKKKT. The method of packing which is now coming into use is to pack the fruit in the orchard, u>ing packing tables built upon runners. These are hauled down a row, stopping at intervals. Two rows are picked on either side of the table, and the fruit is carried from the trees to the tables by the pickers. The fruit is there graded and packed, and 651.1: — No. 41 — 03 5 66 the culls are left in piles in the orchard. The advantages of this method of packing are man3\ The fruit is handled but once, and is not hauled any distance until it has been securely packed, and the danger of breaking the skin or bruising is reduced to a minimum. The picking and packing crews also work as smaller units, and can be more easily directed and do far better work. The codling moth larvae in the culls, after completing their development, will, if allowed to do so, spin their cocoons among the apples in the piles. (See PI. XV I.) Fruit may be well grown, well colored, and of proper varieties, but if not well packed these conditions are nullified. Apple growers in the Far West are confronted with rather special problems. B}^ reason of their distance from the large markets of the United States, the price they would receive for second-quality fruit w^ould hardly be sufficient to pa}^ the expense of growing, packing, and shipping, and it is incumbent upon them to ship nothing except that which is strictly first class, packed in strictly first-class manner. The cost of transpor- tation, prevailing market price, and size of crop, however, must be taken into consideration. The methods of packing depend upon the kind of package used. Eastern grown apples are usually packed in barrels. From Colorado and Montana Avestward boxes containing either 40 or 50 pounds are almost universally used. Some are even going further, using small packages containing half bushels of superior fruit. There are many methods of packing the fruit in these boxes, as ma}^ be required b}^ the purchasing dealers. In all cases it is highly essential that the fruit be packed so tightly in the box that there can be no shifting of posi- tion Avhile in transit; that there be a decided swell in the boxes on both top and bottom if they are made of thin and fiexible wood, as is usually the case in the West; that the paper lining of the box remain unbroken, and that when the fruit is opened it will be attractive to the bu3"er. The more progressive fruit grower is well aware of the fact that a reputation for first-class fruit can be obtained and secured only b}^ packing such fruit and rigorously excluding all wormy or scale- infested apples. Although it is extremely difficult for a packer to put up a box of apples containing not a single wormy fruit, it should be firmly impressed upon his mind that is the ideal to be attained. The second-quality apples, which are usuall}^ disposed of in the local markets, are those but slightly injured by the codling moth, or undersized or uncolored. The culls and windfalls should be piled together and disposed of as quickly as possible. They may be either fed to stock immediately or made into cider for vinegar. The value of these culls is considerable, and progressive orchardists count a good deal on the revenue derived from them. From the seconds, culls, and windfalls in one orchard with which the writer is familiar 67 5,000 gallons of cjder woro made, whicli sold for as lii^li as 20 cents per gallon. One bushel of apples made from 2^ to y>i: gallons of cider, by means of a hydraulic press run })y the gasoline engine used in spra^ang. If it is not possible to dispose of the culls otherwise, they should be buried in holes in the orchard and covered over Avith 6 to 8 inches of closel}^ packed earth. (PI. VI, fig. 2.) Occasions may arise when it is necessary to store these for some time, although the storing of such fruit should be avoided if possible. Fruit should be stored in a house in which there are no holes or cracks in the roof or walls. When the larvte inside the fruit have completed their development they spin cocoons and transform into pupa3, which in turn transform into moths. These moths emerge, and if there are cracks or holes in the house they will escape and fly to the orchard the follow^ing spring. If, how^ever, the house is tight it may be fumigated; or, better still, screens may be placed over the windows, and as the moths collect upon these screens, they may be crushed, or they will die if left a week or so. The writer studied two cases in Idaho in which apples wxre stored quite near an orchard. (PI. IV, figs. 2 and 3.) The effect was that the following year the part of the orchard nearest the apple house was always most infested, and in spite of all the remedial measures applied there w^as a great amount of damage. In California it was found by Mr. De Long that in a house in which apples were stored the moths alwaj^s emerged and went to the windows. Kecords were kept of these insects, and it was found that 11,971: moths were killed from April 15 to August 12. One can easily imagine Avhat destruc- tion these moths would have caused had they been allowed to fly to the orchard. PREVENTIVE MEASURES IN OLD ORCHARDS. In all sections of the country old neglected orchards are easily found in which practically all of the fruit is infested ])v the codling moth. The Avriter is quite familiar with two typical orchards, one of which is situated in an irrigated section of the far West and the other in a humid section of the East. Although the climatic and other conditions are quite ditt'erent the two orchards have many featuivs in t'omnion. The western orchard consists of about 300 trees about 18 or 20 3^ears old, planted about 1(5 feet apart each way. The branches of each tree touch those of the surrounding trees so as to form a dense mass of branches and foliage. Theformer owner of the orchard, flnd- iiig that the codling moth destroyed the larger part of the fruit, oavo the orchard no irrigation, and in cohsihiucmuh* the tnnvs are in a more or less stunted condition. The l)ranches are thickly matteil too-other, having never been pruned. The trunks and branches of the trees are 68 covered with rough scales of bark, and where branches have been cut away the stubs remain, with irregular cut ends, the branches hav- ing been hacked oS with an ax. These stubs have in many places cracked and begun to decay, thus making excellent places in which the larva? of the codling moth could spin their cocoons and hibernate. The writer once secured 20 larvae from the holes and cracks in one of these stubs. The cut ends were not given proper ^""ressing and decay has taken place, often leaving large holes in the trunks and branches. Many cocoons can be found in this rotten wood, and on all the trunks and branches one can lind numerous empty pupal skins from which moths have emerged. The soil of the orchard has received no cultiva- tion and is covered partly with weeds, principally prickly lettuce. The orchard is very productive and always bears a good quantity of fruit, but, being undersized and from 90 to 9S per cent infested by the codling moth, practically no revenue has been derived from it for the past live or six years. In 1900, 1901, and 1902 the writer searched carefully for uninfested fruit, and each time found on the tree near the trunk only a dozen or so small stunted apples which had escaped the codling moth. Other insect pests are present in this orchard, each requiring special treatment. The eastern orchard is situated in a good horticultural region. The trees number about 300, and are probably about twenty-five years old. They are placed 10 feet apart, and have made a good growth. The trees have received some pruning, but as in the western orchard there are man}^ stubs left, and there are numerous decayed holes in the trunks and branches. In many trees the branches are matted together and shade the fruit. The soil is in fairly good condition and lightly sodded. Until the ])ast two or three years the orchard has been remarkable for its productiveness, but a large percentage of the fruit was small and much the larger part of it was infested with the larvae of the codling moth. The treatment that these orchards should receive to bring the cod- ling moth under control is about the same. It may be stated that if the preventive measures advised for a young orchard had been faith- fully and intelligently carried out man}^ of the existing conditions would not have been present. TREATMENT OF OLD ORCHARDS. The first thing to be done to old orchards is to prune the trees in such a manner that the sunlight and spraying solutions will have easy access to the foliage and fruit. Every other tree in the western orchard should be cut down. The stubs of branches should be sawed off close to the trunks and burned in order to destroy the hibernating larvae contained in them, and the cut ends remaining on the tree cov- ered with shellac varnish or grafting wax. The holes in the trunks 69 and branches should be filled with cement, plaster, or clay, in order that the insects inside niay be confined and die. and that other larvte later in the season will be unable to enter to spin their cocoons. The rough bark on the trunks and branches should be scraped awa}' and burned. In both of these orchards it is a noticeable fact that the woodpeckers have been very efficient in digging out the hibernating larva*. (PI. VIII.) It has been often noted by authors that early in the spring it is almost impossible to find larva? of the codling moth under the rough bark and other exposed places in badly infested orchards. Instead of finding the cocoons with the larva^ inside, one will find empty cocoons with a hole through the bark of the tree, showing that the insect has fallen prey to woodpeckers. All places in which the larva? might spin cocoons should be destro^^ed or rendered unsuitable, and the larvae forced to spin cocoons in exposed places where the wood- peckers and other birds can get them. The soil in these two orchards should receive about the same treat- ment, except that irrigation should be begun in the western orchard. Thev should both receive a ver}' shallow cultivation for about one year, with a dressing of manure. The cultivation should be so shal- low as not to injure any of the roots, which may be quite near the surface. The second year, red clover, cowpeas, or some other legu- minous cover crop should be sown, and every third year this may be turned under, thus adding available plant food to the soil. When these methods are followed the recommendation given for an orchard in l)earing should be adopted. At best the preventive measures can not control the insect in an orchard. ])ut they are valual)le adjuncts which render the measures more efficient. REMEDIAL MEASURES. Remedial measures against the codling moth are those measures from which little or no benefit is derived except in saving fruit from the ravages of the insect by killing it. MEASURES OF LITTLE OR NO VALUE. The codling moth seems to have been common in orchards for many centuries, but no one made any suggestions as to how its ravages might be checked. The first reconunt^ndations made were of no value, aiul it is interesting to note how thoe i-econuuiMidations have recurred at various periods in popular writing>. Many of these riMuedie>, having little or no value, are takcMi up by companies, given all the benefit of modern advertising methods, and thoroughly distributed before the fruit growers beconu> aware of their worthlessness. In order that the fruit ui'owcr mav know what not to do as well as what he 70 should do, a number of the more prominent of these ineiBcient methods are briefly discussed. It has often been recommended that moth balls be hung- in the trees in order to keep the moths away. If there were any virtue in this remedy, so many of the moth balls w^ould have to be hung on each tree, to do the work, that the expense would render it valueless. Smudging the orchard, or burning ill-smelling compounds so that the fumes will pass through the trees, has been practiced to some extent. The theory is that the moths will be kept awa}^ by the fumes and go to other orchards to deposit their eggs. It is quite evident that as soon as these fumes are blown out of the orchard the moths will return if they have left, and in order to produce any results it will be necessary that the smudge be continued practically^ throughout the season. Plugging trees with sulphur or other compounds and plugging the roots wath calomel have been practiced to some extent, on the theory that the sulphur or calomel will be taken up by the sap, distributed through the tree, and prove distasteful or poisonous to the insect. Trustworthy scientific experiments have been carried on which show that it is absolutel}^ impossible for the tree to take up any amount of these substances, and little or no effect upon the insects results. The writer has found several orchards in which the trees were banded with tarred paper, the evident intention ))eing to keep the larv?e from getting up into the trees. Knowing the habits of the insect when in its larval form, we can see that this method is ridiculous, and instead of being a detriment it is a positive aid to the insect; in many cases larv?e were found which had spun cocoons under the bands, which formed a place in which they were comparatively free from the attacks of their enemies. There seems to be a popular idea among many farmers and fruit growers that all insects are attracted to light. Based upon this idea, there have been many recommendations to keep fires burning in the orchards, or to arrange some sort of a trap lantern by which the insects are to be attracted to the lights and fall into water on which is a film of kerosene and thus be killed. This scheme of trap lanterns was exploded many years ago, but it seems that at intervals somebody revives it, and its fallacy must be exposed afresh. By carefully experimenting with trap lanterns and determining the catch as accu- rately as possible it is found that the majority of the insects caught are either decidedly beneficial varieties, or are males, or females which have already deposited their eggs, and that but few^ injurious insects are caught, and none in any great number. Probably the most exten- sive experiments with trap lanterns were those conducted by Professor Slingerland. Among 13,000 insects he was not able to recognize a single codling moth. This is the usual result of all these experiments, 71 and wo can say without any hesitancy whatever that the fanner who uses these trap huiterns or tries to experiment with thenj is simply wasting his time and money, as the method has })een thorou^-hly })i-o\en inefiective. It is also the practice to some extent to put cans or l)ottle> contain- ino- molasses, cider, vinegar, or some other substance of similar nature in the oi-chard. and upon tinding that insects are attracted by these compoimds and killed, many fruit growers think this is a good remedy for the codling moth. The results of many careful expi'riments show that only incidental captures of the codling moth are made. With both these last two practices — that is, trap lanterns and baiting the moths — the greatest trouble has been that the fruit growers are not accjuainted with the codling moth in its early stages. Any fruit grower can breed moths for himself, and l)y comparing his catch can very easily satisfy himself. Many times fruit growers have tried spra3'ing their orchards with ill-smelling compounds with but little success. These compounds are always more or less expensive and have never been so efficient as to justify their use. Other fruit growers think that spraying the orchard with water fre([uently will give relief from the attacks of the codling moth. Undoubtedly if the trees were kept in a spray all the time, the fruit would be clear of the insect; ))ut if this were done, the probabilities are that no fruit would set, and if any should set it would not ripen well, and the trees themselves would probabh^ die. The expense of this operation would l)e many times greater than that of spraving. It has l)een stated that electric lights repel the moth and that trees near electric lights in cities are often free from its v,ork. The writer had an excellent opportunity to investigate this point, and found that an apple tree about 40 feet from an electric light was as badly infested as any other in that vicinity. In order to do away with the lai)or entailed by using bands around the trees many kinds of traps have ])een invented. Hiley. l)y careful expei'iments, showed that one of these tra])s would not catch as many larvie as the bands; and other experiments have shown that these patent traps are never very efficient. It was claimed for some time that the llowers of i)lants of the genus Phy.sidiit/dis might })e efficient against this insect, since in order to reach the honey of the flower the proboscis would have to be passed through a narrow cleft, from which it could not be withdrawn, and the moth would therid'ore ))e held a i)risoner until it tlitnl. It wa> proposed to train the vines around the trunks and l)ranches of the trees, and, the moths IxMug captured, the orchard would be protected. C onclusiv(^ evidenci^ has been riH-ordiHl which >hows that those tlowors ha\i' no attraction for the codliiiLi- moth. 72 It has been suggested tlmt the codling moth might be controlled by 'bacterial and fungous diseases. From the facts that the insect leads such a protected life and that fungi and bacteria have given so few positive results in this connection it is almost useless, Avith our present knowledge, to even theorize upon the value of these agencies. In general it ma}^ be stated that entomologists have at all times tried experiments with these different plans and are unanimous in their conclusions. If anything new and efficient is ever perfected by which this insect ma}^ be more easily controlled, no doubt entomolo- gists will be its lirst advocates. MEASUEES OF VALUE. By taking into consideration all the habits and variations of habits of the codling moth in its different stages we find that, like other insects, there are certain stages in its life history in which it is more amenable to remedial measures than at others. We find that it can be best attacked in the larval stage, although some experiments indicate that something can be done when it is in the Qg^ stage. Cook found that by spraying an apple tree weekl}^ from May 15 until the end of June with a strong soap solution he succeeded in preventing the infesta- tion of a single apple by the larva?. In laboratory experiments with kerosene emulsion Card secured good results against the eggs. Gillette also obtained good results with kerosene emulsion. The results of these experiments have never been put to practical use for many rea- sons. The kerosene emulsion would probably be so strong, in order to have an}^ effect on the egg, that it might injure the tree. The kerosene would eva])orate quickly, and thus its effect would be for but a short time. The expensiveness of kerosene in the West, and the number of times the spraying would have to be made to be efficient, would prohibit the adoption of this method. The insect can be more easily attacked, at less expense and with greater effectiveness, in the larval stage. MEASURES USED AGAINST THE LARVA. The remedial measures used against the larva vary according to whether they are used after it has been hatched and before or while it is entering the apple or after it has completed its growth and left the fruit. The greater effectiveness is secured by the use of arsenical sprays before the larva has entered the fruit. The effectiveness of these arsenical spravs against the codling moth was discovered by accident in 1872. Le Baron recommended the spraying of trees with Paris green to check the ravages of the canker worm, which recom- mendation was adopted in man}^ orchards with great success. Profes- sor Slingerland states that the credit of this discover}^ belongs to Mr. E. P. Haynes and Mr. J. S. Woodward, who found that spraying with 73 Paris green not only rid the orchard of can kerw onus, but that the apples on the sprayed part were much less affected by the codling moth. It seems that other people used Paris green for cankerworms in Iowa, but there are no indications that they were alive to the fact that at the same time they were checking the codling moth. Prof. A. J. Cook, of Michigan, took up the idea and by a series of careful experiments clearly showed that the treatment was very effective against the codling moth. Forbes, Goff', and numerous others have at various times carried on spraying experiments with arsenicals, with results that show this to be the most effective and cheapest remedial measure that can be used. Spraying with arsenicals may be defined as putting a coat of any arsenical poison on the foliage and fruit of a tree, so that when the insects eat the foliage or enter the apples they eat some of this poison in their first few meals and are killed. Since the beginning of the practice of spraying there have been many important improvements in both spraying machinery and spra^nng solutions, which have ren- dered the process much easier than when primitive methods were in vogue. SPRAYING MACHINERY. There are as man}^ kinds of spraying machinery as there ar(^ condi- tions to be met in spraying operations. There are certain spraying outfits devised especially for orchard work, varying from the common bucket pump to rather complicated machiner}^ driven by gasoline engines. For a small home orchard or for an orchard of a thousand trees or less the writer would advise the use of a hand-power outfit. The capacit}^ and cost will depend primarily upon the size of the orchard, the size of the trees, and the rapidity with which it is desired to spray the orchard. There are many excellent types of spray pumps on the market, and no mistake can be made in jjelecting any of the outfits of the ])etter manufacturers, ])ut there are several })()ints whii'h should be insisted upon. The interior fittings of the pump sliould i)e of brass and should be arranged so that the inside of the cylindiM- can be easily reached in order that repairs may be made. The air cham- ber, which insures a steadier stream and acts as a reservoir of force, is almost a necessit}^ A pressure gauge upon this air chamlxM- will be of great value, as it will aid the man who does the ])umping to keep the pressure at about the sanu^ point. The })ump may ho mountiul upon a barr(d, wliich may be stood on (Mid or put on tlu^ side, or it ma}^ be mounted on a taidv or upon the wagon frame on which the tank is mounted. Tliese tanks iwo i)referably of wood, and should l)e of ver}' strong construction and securely bolted togi^ther with iron rods. Screens should be used to strain out particles wiiich would clog 74 the nozzles, a.nd should be used both as the water is put into the tank and as it is pumped out. It is highly essential that some mechanical device be used to keep the liquid in agitation so that the coarser par- ticles will not settle to the bottom of the tank and render the mixture of variable strength, especially if Paris green is used. The hose may be any of the t3^pes in use, and a hose extension of some light tube, covered preferabh^ with bamboo, should be used in order that the tops of the tall trees may be easily reached. A stopcock at the junction of the hose and extension can be used to great advantage. The nozzles most used in spra3dng orchards are of two t3^pes — those which throw a fan-shaped spray, which are used for long-range work, and those which throw a cone-shaped spra}^, which are used for close work. Several of these nozzles may be placed on one bamboo exten- sion, and thus the amount of liquid thrown increased. Four lines of hose may run from one pump, but it is found that so large a number causes confusion and that more work can be done with two lines of hose. The usual number of nozzles upon each extension or line of hose is two. The nozzles can be set at an angle to the axis of exten- sion, and then by turning the extension the stream can be variably directed. If the spra3^ing outfit is small, consisting of a barrel with a pump, it can easily be hauled through the orchard on a sled; but if the outfit is larger it is usuall^^ drawn upon an ordinary wagon. Details of the mounting on the wagon and the position of the pump and tanks will depend a great deal upon the facilities which the grower has at hand. Many have the tanks and pumps mounted upon a frame, which the}^ can put upon the wagons and remove when the spra34ng is com- j)leted. If it is desired to spra3^ very tall trees, it has been found that spraying can be done more rapidly and thoroughl3^ if there are high platforms built upon the wagons upon which the operators can stand (fig. 17). The capacit3" of these hand-power spra3'ing outfits depends upon man3^ factors, such as the number of men emplo3^ed, size of pump, number of nozzles, capacit3^ of tank, distance from water sup- pi 3^, and size of trees. It has been found that three men, using a 200- gallon tank and two lines of hose, each fitted with two nozzles, can spra3^ about 250 average-sized trees per da3^ These hand-power spra3^- ing outfits can be purchased and put in working order for from $15 to $75. A pump, if used for arsenicals alone and given good care, should last for five or six 3"ears with but few repairs. But if the same pump is used for spra^^ing with the lime, sulphur, and salt com- pound, and the compound allowed to corrode the pnmp, it w^ill be necessar3^ to purchase a new pump oftener. (See Pis. XI and XII.) GASOLINE-POWER SPRAYING OUTFITS. If an orchard consists of more than a thousand trees, it will be found expedient to use a gasoline-power spraying outfit. If the orchard 75 consists of five to ten thousand trees, it will be found that the ex|K'nso per tree with this outfit is only about half of what it would b<' with hand-power sprayers. Many dealers have placed spraying machines on the market in which the power is derived from gasoline engines. They consist largely of engines, pumps, and machinery for other uses, placed together for this purpose. AVhile a majority of these are quite well adapted to the work of spraying, many improvements are possible which would Fig. 17 —Spraying outfit for treating tall trees (after Gould). increase ethciency without inricasing rost. There are many makes of gasoline engines, most of which are well adaptod to this work. The horsepower of the engines is usually too large. An outfit with which the writer is most familiar is run ))y a 1 V-horsepower gasoline engine, and in ordinary spraying optMations it was found that the engine was too powerful, as four out of nine possible explosions were all that was recjuired to run th(^ ])unips and k(M'))tht> pressure at l(M) pounds. The engiiK^ for spraying purposes should Uo about 1 horst^pi>W('r. which 76 may be more than is required at ordinary times, but occasions may arise when more power would be desired. There are many methods by which gasoline is fed into the cylinders of these engines. The better engines have a pump by which the gas- oline is forced into the cylinder. The ignition is accomplished by one of two methods — either by an ignition burner on the outside of the cylinder which communicates heat to a platinum point which explodes the gasoline vapor, or by an electric spark from an induction coil which is connected with numerous dry batteries. The cooling tank used with these engines for the purpose of keeping the cylinder moist and cool is usually from 12 to 14 inches in diameter. This size is intended for stationary engines, where the water can not be renewed frequently. In spra34ng, however, the water can be renewed ever}^ few hours if necessar}^; and therefore the tanks can be built as small as 6 inches in diameter, which will make a considerable reduction in the weight of the machinery. Purchasers are always given full instructions in regard to the care and running of these engines, so that one with comparatively little mechanical ingenuity has ver}^ little trouble. The greatest source of difficult}^ is with the electric current. The insulations often become imperfect or the sparking points become dirt}^ and fail to produce a spark. B}^ carefully testing the current and keeping these points clean practically all of the trouble is avoided. It is preferable to place the engine at the rear end of the frame and the pump as near the engine as possible. There are two types of spray- ing pumps which ma}^ be used for this purpose — the triplex pump, which consists of three vertical plungers, and the straight horizontal double-acting force pump. Either of these pumps will be found to answer to the conditions required for these outlits, but the horizontal pump is more commonl}^ used. The pumps should be so manufactured that all of the parts are accessible and the brass lining easil}^ removed. The working parts should be made of brass or bronze. A large air chamber is essential, as well as a pressure gauge. It is absolutel}^ necessary that a relief valve be attached to the pump, so that when the stopcocks on the bamboo extension are closed the engine will not have to be stopped, but at a certain pressure the spraj^ing liquid Avill be returned to the tank. In sections of the countrj" where irrigation is practiced it has been found that the most effective method of filling the tank is to have another pump which can be attached to the engine, by which water can be pumped from an irrigating ditch into the tank. This pump should belong to the t3'pe known as "low-down pumps," which deliver large quantities of water at low pressure. The suction hose should be 2 or 3 inches in diameter and the end which is put into the irrigating ditch should be w T screened. There is usually some 77 method by which this pump can be connected with the engine. It is unnecessary to disconnect the spraying pump from the engine, as the suction hose of the spray pump may be removed from the spraying tank. This filling pump and connections can be purchased for about $20, and the time and labor saved b}^ its use will pay for it many times over during the season. This idea of having a filling pump attached to the spraying machine was originated and carried out suc- cessfully by Hon. Edgar Wilson, of Boise, Idaho. As before stated in regard to hand-power outfits, it is found nuich more expedient to use onl}^ two lines of hose. The length of this hose will depend upon the method used in spraying the trees. Bam])00 extensions and nozzles are the same as those used in power outfits. It is found that water from irrigating ditches contains a considerable amount oi sand. The effect of the sand and the lime in the spraying solution is to cause the face of the nozzle to become badl}^ worn, ren- dering it unfit for use in five or six days of continuous spraying. Letters have been written to the more important manufacturers call- ing their attention to the fact that if these faces were hardened or made of steel the nozzles would last much longer, and it may be that these firms will shortly put such improved nozzles on the market. The tanks used in these spraying outfits may be made of wood or galvanized iron. The latter would be preferable on account of its lightness, but it would be disadvantageous because it would be some- what difficult to thoroughly brace it. The tanks should not have a larger capacity than 150 gallons and should be placed on the front end of the frame. Screens should be placed over the end of the hose lead- ing from the filling pump, as well as over the suction hose from the spraying pump. The agitator which has given the best satisfaction in this connection is formed ])y two paddles set at an angle, mounted on a vertical shaft, and run by power derived from the gasoline engine b}' means of a belt and bevel gearing. This agitator keeps the spraying solution in violent agitation and renders it uniform. The whole machine, engine, pumps, and tank should be mounted upon a rigid frame. On this frame there should be a platform at either side, with a railing, upon which the operators can stand. There should be supports for the bamboo extensions placed near the center of the outfit. (PI. XI, tig. 2.) This frame can be mounted upon an ordinary wagon, but it is preferable to use a low wagon with steel wheels and tires not less than 6 inches in width, which will largely pre- vent the wheels from sinking into the soft earth. A team and two men are required to operate this outfit. Both of the men spray; one drives, and the other starts and stops the engine. This reduction of labor makes a material reduction in the cost of spraying. Many tests have been made of these machines working under actual 78 conditions, and it is found that TOO trees (in the West, where they are considerably larger than trees of the same age in the East) can be easily sprayed in one day. Some fruit growers tell the writer that they have been able, when they found it necessary to work more rap- idly, to spray 900 trees per day. By a series of observations it has been found that it takes from four to five minutes to fill the tank by means of the filling pump, and the same amount of liquid can be sprayed out in from thirty to forty minutes, upon from 60 to 80 trees, depending on their size, using about 2^ gallons per tree. In an irri- gated orchard it is quite desirable that the ground be allowed to become dr^^ before the spraying is begun, and thus avoid miring the machine in the soft earth, which will frequentl}^ occur in wet places in the orchard, especialh" when the tank is full. The cost of these complete machines varies with the cost of the engine and pump and their fittings. They can be purchased for from about $260 to $500. The machine with which the writer is most familiar cost $320, which included a $40 wagon and filling pump and attachments at $20. With good care and proper repairs these machines can be made to last for several j^ears. In a working da}^ of ten hours it was found that a li-horsepower engine consumed about 1 gallon of gasoline. Although the initial expense of this outfit is greater than that of the hand-power outfit, it will be found to be much cheaper in the end, as the engine can be made to more than pay for itself by other uses when sprajdng is not in progress, such as running the cider press, feed cutter, and cream separator, sawing wood, turning the grindstone, and numerous other tasks about a farm for which power is desired. The machinery can also be removed from the wagon and stored in an outhouse and the wagon used for other purposes. WATER SUPPLY. The distance of the water supply from the orchard is one of the greatest factors in determining the rapidity with which spraying can be done. W^ith the water supply some distance awa}" much valuable time is lost in going to and fro to fill the tank. In the smaller orchards, where but little spra^ang is done, the usual custom is to drive the wagon to a ditch, pool, or well, where the water is trans- ferred into the spraying tank with buckets. Many fruit growers have found it advantageous to draw their suppl}^ of water from an ele- vated tank into which water is pumped by a windmill or piped from some spring or stream. For irrigated orchards the water is usually taken direct from the irrigating ditches, sometimes from the main ditch and sometimes from the lateral ditches running through the orchard. By taking the water from these laterals in the orchard the routes of the spraying apparatus in operation can be largely deter- mined, the foreman trying at all times to be near one of them when 79 tho tank becomes empty. By hk^ids of the filling- i)umi) on the (gaso- line power outfits iimch vahui})le time can })e saved in the operation of tilling the tank, as compared with the method of having an extra wagon to liaul water to the spraying outfit, sometim(\s employed. The routes followed ])y the spraying machine in the orchard depend upon many factors, such as source of water suppl}^, position of hills and ridges^ and direction of wind. Each orchard is a pro})lem \)y itself, and experience will show which routes can be followed with the least loss of time. APPLICATION OF SPRAY. There are many methods of spraying the trees. In following the chosen route through the orchard some use four lines of hose, com- pletely spraying four rows of trees at a time; but it has been found in actual practice that on account of the long hose and the great dis- tances the men have to walk other methods are more advantageous. Many use two lines of hose, and men standing on the ground go com- pletely around the trees, thus spraying two rows on all sides. Other fruit growlers drive down one row and spra}' half of the tree on either side; coming back on the other side of the row they spray the other side and one-half of the next row. It has been clearly shown that this method gives the best results, both in the saving of time and in com- pletely covering the trees. When the trees are tall it is quite neces- sary that the men ride upon an elevated platform, and it has also been found advantageous in using the gasoline-power outfit to have the men ride on the apparatus. In this way not only the men are saved unnecessary labor, but from their elevated position they can spray the trees more thoroughly. With the nozzles set at an angle on the l)am- boo extension, part of the tree can be sprayed as it is being approached. Then on stopping at the tree the whole side can be sprayed, and when leaving it the last part can be spra3'ed and spraying be begun on the next tree. It is almost impossible to spray wdiile moving at right angles to a strong wind, and if such a wind is encountered it will be found desirable to have the wagon go either with or against it and take advantage of it 1)}^ allowing it to blow the mist through the trees. PLxperience on the part of the operators will enable them to devise UK^thods to reduce the time without impairing the effectiveness of the spraying. The ideal to ])e attained in applying spray is to cover the tree with a thin coating of the spray solution, so that when the water dries it will leave a coating of poison on ever}^ portion of the foliage and fruit. When the spray is applied with but little force the stream does not break up into sufficiently fine globules, and when tliey strike the foli- age they either cover only a small portion of it or run together into large drops and fall to the ground, leaving but little of the solution on the tree, and that little ver}- much scattered. If, however, the spray 80 is applied with great force, the stream is broken up into a fine mist, which, if well directed, is evenly distributed over the foliage and fruit, and upon dr3dng leaves a more or less uniform coat. If the nozzle is held close to the foliage, the force causes it to spread well, but the coating is not so uniform as that which is derived from the mist. In spra^^ing one-half of a tree the mist drifts through the tree from the side which is being sprayed, and in that way the tree is well covered, having received practically two incomplete sprayings. If fruit is allowed to grow in clusters it is necessary to apply the spray with great force in order to secure good results. MATERIALS FOR SPRAYING. CONTACT INSECTICIDES. Contact insecticides are those which kill the insects by touching them. Kerosene emulsion and solutions of whale-oil soap are the sub- stances that have been most used for this purpose; but on account of the expense, the necessity of frequent application, and the fact that the insect can be more easil}^ and effectively reached in other stages by other insecticides, these kinds of spraying solutions have been used but little against the insect. AESENICAL SPRAYS. The arsenical spra3\s contain arsenic as their essential ingredient. Other chemicals are mixed with the arsenic for the purpose of pre- venting it from burning the foliage or are products incidental to the numerous compounds of arsenic which were used for other purposes than spraj^ng. There are man}^ spraying compounds of which arsenic is the base on the market, but there are many others which the fruit grower can make for himself by combining the necessary ingredients. Paris green is probabh^ the best known of these arsenicals. It has been used for man}' 3'ears with success, and is a definite chemical com- pound of arsenic, copper, and acetic acid. The composition is usuallj^ quite uniform, but many instances have been found in which it was adulterated or the percentage of soluble arsenic was dangerously high. As indicated b}^ its name, it is a substance green in color. It is a rather coarse powder, which has the fault of settling rapidly in the spraying tank. It is quite necessary to use lime with Paris green in order to counteract the burning effects of the free arsenic. Paris green is comparativeh^ expensive; in the East it costs about 20 cents a pound and in the West 25 cents. Paris green may be prepared for spraying as follows: Paris green . - pound. . 1 Lime pounds . . 1 to 2 Water gallons. . 100 to 250 Bui. 41, Div. of Entomology. U. S. Dept. of Agriculture. Plate X. Fig. 1.— Band on which the Remains of 330 Cocoons were Counted. Fig. 2.— Pupa in Cocoon on Underside OF a Loose Piece of Bark. Fig. 3. — Larva and Pup/e in Cracks IN Bark, from which Rough Bark has been Removed. Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate XI. Fig. 1.— Gasoline-power Sprayer, Showing the Engine and Spray Pump. Fig. 2.— Gasoline-power Sprayer as it was Improved During the Season. Fig. 3.— Same Sprayer as in Fig. 1, but Seen from the Other Side. Showing Filling Pump and Attachments. GASOLINE-POWER SPRAYING MACHINES. I Bui. 41, Div. of Enlomology, U. S. Dept. of Agriculture. Plate XII. Fig. 2.— Filling Tank by IVlEA\b uh rut tilling Pump from an Irrigation Ditch. Fig. 3.— Hand-power Spraying Outfit, in which the Pump is Mounted Upon a Barrel on an Ordinary Wagon. SPRAYING OUTFITS IN USE. 81 The lime should ]>e fresh and slaked in small quantities as needed. B}' mixino' a small quantity of water with the Paris g-reen until a paste is formed it is much more easily distributed in the water. The lime may be added to the water in the proper quantity. A good average strength of this solution is 1 pound of Paris green to 15U gallons of water; but for trees with delicate foliage, such as peach, it is advisable to use a much weaker solution. Man\- fruit growers are using Paris green of the strength of 1 pound to 100 gal- lons, with the addition of lime upon apple trees, without burning the foliage. ScheeJes green is a similar preparation to Paris green, but differs from it in lacking the acetic acid. It is a finer powder than Paris green, is much more easily kept in suspension, and the cost is only about half that of Paris green. There is but little of this insecticide manu- factured and placed upon the market. London purple is a waste product in the manufacture of aniline dyes. It contains a number of substances, of which the principal ones are arsenic and lime. It is quite variable in composition, and is gen- erally considered as being not so effective as some of the other arsen- icals. For spraying it is now being replaced by the other poisons. Both Scheele's green and London purple are prepared for use in spraying similarly to Paris green. WHITE ARSENIC COMroiXDS. If white arsenic is used alone in spraying, it will seriously injure the foliage of the trees ])y ])ui'ning. but when combined with other chemicals which prevent this burning, it forms the base of our most eft'ecti^'e spra3's, any of which can be easily prepared by the fruit grower. Arseniie of lime. AVhite arf^enic pound . . 1 Lime pounds. . 2 Water irallon . . 1 The white arsenic* and the lime are boiled together for not less than half an hour in the recjuired amount of water, as it is very ditticult to make th(^ lime and arsenic combine. After the combination is com- plete enough water is poured in to replace that lost by evaporation. This solution may be ke])t as stock, and 1 pint of it ustnl to every 40 or 50 gallons of water. It is advisable to add more lime to this spraying solution in order that all danger of burning may be avoided. Although this solution is by far the cheapest spmying material, there is much danger of poor combination of the arsenic and lime, leaving free arsenic, which will injure the foliagt\ In order that the lime may more thoroughly coml)ine with the arsenic, soda has been used to facilitate the combination. ()51-I:— No. 41— Uo 0 82 Arsenite of Jhne with soda. White arsenic pound. . 1 Sal soda (crystal) pounds. . 4 Water gallon. . 1 The ingredients are boiled in the required amount of water until dissolved, Avhich will take place in a comparatively few minutes, after which the water lost by evaporation is replaced. To every 40 or 50 gallons of water a pint of this stock solution and from 2 to 4 pounds of fresh slaked lime are added. The chemical compound derived from the combination of the sal soda and the white arsenic is arsenite of soda. In the presence of lime this breaks down and arsenite of lime is formed. It requires 4.4 pounds of cr^^stal sal soda or 1.6 pounds of dry sal soda to combine with 1 pound of arsenic and 2 pounds of freshly slaked lime to combine with 1 pound of arsenic to form arse- nite of lime. It is always desirable to have an excess of lime present, in order to prevent all danger of burning; furthermore, this excess is a convenience to the fruit growers, because they can see b}^ the distri- bution and amount of lime on the foliage how well the spraying has been done. This formula, which is the Kedzie formula, with a A^ery few minor changes, has been used in many different sections of the countiT with unvarying success. In all of the practical tests under the advice of the writer this solution is used, and is found to be not only as efficient as other solutions, ])ut far cheaper. Arsenate of lead. Arsenate of soda ounces. . 10 Acetate of lead do 24 Water gallons. . 150 to 200 The arsenate of soda and acetate of lead should be dissolved sepa- rately and then poured into a tank containing the required amount of water. These chemicals unite readily, forming a white fiocculent pre- cipitate of lead arsenate, which is easih^ kept in suspension, and can be used in excessive strengths on delicate plants without the addition of lime. When sprayed upon the foliage it forms a hlmy, adhering coat, which is but little affected by ordinary rains. There are several good preparations of lead arsenate upon the market. Some of these are prepared in a w^et state, others in a dry or powdered form. The moist l^reparations are much preferable, because the dry powder does not give such a good coat of poison upon the foliage. This poison has given excellent results in use against the codling moth, but on account of its expense it is comparatively little used. If it is desired to use Bordeaux mixture with any of these solutions the arsenicals are added to the Bordeaux mixture in the same propor- tions as they would be to a similar quantity of water. At all times the greatest care should be taken to prevent accidental poisoning with 83 these compounds/' The fact should ))e firmly impressed upon all those who have anything to do with these solutions that they are of the most poisonous nature. All packages, boxes, or bottles containing the materials should be plainly labeled and kept insecure places which can l)e locked. The utensils in which the mixtures are prepared should he thoroughly cleansed or kept in some secure place, so that no mis- take can occur in using them for other purposes. COST OF SPRAYING. The cost of spi'aying is so small when compared with the benefits to be obtained that we can say it is the very best investment the grower can make. As with other farming operations, the first year will be more expensive than succeeding 3'ears, as b}^ experience the fruit grower will be able to reduce expense considerably without impairing efficiency. It is a vorv difficult task to estimate the cost of spraying, for many factors enter into the problem. The initial cost of the outfit varies from Slo to 875 for hand-power outfits and from ^260 to ^'275 for gasoline outfits. These outfits can be used for many years, and the parts of the gasoline outfit can be used for other purposes. The cost for spraying material amounts to little. The cost of the difierent spraying materials will vary with the difierent sections of the country, according to the freight rates and the quantities purchased b}' fruit growers. Where a large amount of (' Although no accidents are known to have occurred from the use of arsenicals in spraying, it is well to know what to do in case of accidental poisoning. If evil effects are noted in the case of persons who constantly handle these poisons, a physi- cian should be consulted. If by any mistake or carelessness a small quantity is swal- lowed, an antidote should be employed without delay. The following extract in regard to antidotes for arsenic poisoning is taken from Poisons: Their Effect and Detection, by A. W. Blyth: "In any case where there is opportunity for immediate treatment, ferric hydrate should be administered as an antidote. This converts the soluble ai-senic acid into the insoluble ferric arsenate, the ferric oxid l)eing reduced to ferrous oxid. It is neces- sary to use ferric hydrate recently prepared, for if dried it changes into an oxyhydrate, or even if kept under water the same change occurs, so that after four months the power of the moist mass is reduced to one-half and after five months to one-fourth. When once the poison has been removed from the stomach by absorj^tion into the tissues the administration of the hydrate is absolutely useless. "Ferric hydrate is i)rei)ared by adding stnuig ammonia to the solution or tincture of ferric chlorid found in every chemist's shoj), care being taken to add no excess of caustic ammonia." Lime water may also be used as an antidote, but it is not so effective :u< ferric hydrate. It is understood that after the antidote some emetic, such as mustard or warm water, should be administered immediately. Persons who use great quan- tities of arsenites in spraying, and who are some distance fn>m drug stores, are advised to keep a small bottle of each of the chemicals named to use in making the ferric hydrate. In preparing ferric hydrate continue to add the ammonia until, after being well shaken, a faint odor of ammonia c;m be observed. 84 arsenites is used it is advised that they be purchased in 100-pound lots, using- 600 gallons of spraying- solution as a basis. Taking the prices of these different compounds as they are in the Far West, the following estimates are made: Paris green: Paris green, 4 pounds, at 25 cents _ |1. 00 lime, 8 pounds 04 Total 1. 04 f^cheele's green: Scheele' s green , 4 pounds, at 12 J cents 50 Lime, 8 pounds 04 Total 54 Lime arsenite: White arsenic, Ih i:)ounds, at 10 cents 15 Lime, 8 pounds 015 Additional lime, 12 pounds 06 Total 225 Lime arsenite with soda: White arsenic, 1 j pounds, at 10 cents .15 Salsoda, 6 pounds, at 1 ^ cents 09 Additional lime, 6 pounds 03 Total 27 Lead arsenate: Arsenate of soda, 2} pounds, at 10 cents 25 Acetate of lead, 6 pounds, at 12 cents /z Total 97 Prepared lead arsenate, 36 pounds, at 20 cents 7. 20 From the foregoing quotations, any fruit grower can estimate the expense of spraying b}" changing the prices to those prevailing in his vicinit}^ The prices of these chemicals, excepting the lime and sal soda, are from about 2 to 5 cents per pound more in the West than in the East. The labor of preparing, which is but little, is another factor which must be included. In the preparation of arsenicals for a home orchard or a small commercial orchard it may be advisable for the fruit grower to purchase the more easil}^ prepared compounds, such as Paris green or prepared lead arsenate, as this does away with much trouble and loss of time in preparing the solution. Labor is the principal element of cost in actual spraying operations. The cost of one spraying for a thousand 8-vear-old trees in the far West, using 2^ gallons of lime arsenite and soda compound per tree, is estimated as follows: 85 Hand-power outfit: Man and team 4 days, at $3.50 $14. 00 Two men 4 days, at §l.oO each 1 2. 00 Materials 1.12 Total 27.12 Gasoline-power outfit: Man and team 1 h days, at $3.50 5. 25 One man 1^ days, at $1.50 2. 25 Materials , 1. 12 Gasoline, 1 h gallons 55 Total 9. 17 The above estimates are taken from actual conditions in the tieUl. and the prices of material and labor are based upon current rates in the far West, where they are considerabh' less than in the East. It is assumed that the men and teams were employed at the local rates; but as men and teams are already employed upon fruit farms, the actual expense of these spra3ung operations is much smaller. Accord- ing to these estimates one spraying w^ould cost 2.7 cents per tree if a hand-power outht is used, or 0.9 cents per tree if a gasoline-power outfit is used. The additional cost to the fruit grower would be nmch less than this, and in some cases would probably not amount to more than 1 cent per tree with the hand-power outfit, or one-half cent per tree with the gasoline outfit. TI^^IE AND FREQUENCY OF APPLICATION OF SPRAT. The time of application of the spra}^ is one of the most important con- siderations in the work. It has been found that in many sections of the country fruit growers have spra3"ed without any definite knowledge as to when the spray would be effective, and many times it was not at all so, the effectiveness that it had depending more upon chance than anything else. Other growers follow the empirical rule of spraying once ever}^ two weeks after the blossoms have faHen. If this rule is followed no doubt many of the sprayings during the reason have little or no effect upon the codling moth. It can be readily seen that to be effective the poi.son nuist be placed ui)on the trees so that when the larv{\3 are hatching they will get sonu^ of the poison; but if they are already inside the apples or in their cocoons they sutler very littK^ from the spraying. Hence we find that where there are ])ut twt> genera- tions of the insect there are only two periods in the seascMi when a large proportion can be affected by the poison, and these are the i^roixu* times for spraying. The work done at these two periods may be termed the early and the late sprayings, the early spraying )>eing directed again,st the first geiHM'ation of the codlino- moth. Two sprayings at the early period are advised, one a t'ew days after the blossoms have fallen and before the calvx closes, and the other 86 about two weeks later, when the majority of the larv?e are entering the fruit. There has been much discussion recentl}" in regard to dis- pensing with the spraying immediately after the blossoms have fallen. It has been found that the lary?e enter the fruit from one to two months after the blossoms haye fallen. In cases of bad infestation, where preyentiye measures haye been neglected, or there is an abun- dance of the insect, it might be well to make three spra3^ings while the second generation is entering the fruit. This period yaries with the localit}" and with the seasons in the same localitj^ ; but there are a few methods by which the time can be approximated with sufficient accu- racy, and in yiew of the fact that the time is variable the writer does not wish to recommend that the spraying be dispensed with until each locality is studied. Spraying may be ])egun immediately after the first new entrance holes of the second generation are found, or about twent}^ days after the date the maximum of the first-generation larvje are found under the bands read}^ to spin their cocoons. The lary^e of the second generation in southern Idaho usualh^ begin to enter the fruit the last week in Juh^, but the majority enter in August, and but few in September. The number of sprayings to be made against this generation depends entirely upon the success achieved against the first generation. It has been found quite definite^ that the injur}^ due to the second generation is much greater than that from the first gen- eration ; and if the injury due to the first generation is from 2 to 5 per cent the writer advises a third spra3dng for the second generation; but if the injury has been only 1 per cent or less, two sprayings will be found sufficient. The quantity of lime used in these late sprayings should be reduced to a minimum, as lime on the fruit depreciates its market value. Light showers wash but little of the spray from the tree; but if there is a heav}^ shower or continued rain, a large amount will be removed, and it will be necessary to repeat the sprayings as soon as possible. Lead arsenate is less afi'ected by rain than the other spray- ing compounds. HOW THE POISON KILLS THE INSECTS. Though Paris green has been used for spraying purposes for many years with success against the codling moth, it is only recently that any serious effort has been made to ascertain how the poison is obtained by the larvae. Slingerland was the first to answer this ques- tion with any degree of accuracy. According to him the spray lodges in the saucer-like calyx when the young fruit is erect after the blos- soms have fallen, and upon the segments or leaves of the calyx clos- ing the poison is held there for some time. As about 80 per cent of the larva? of the first generation enter the fruit through the calyx, it is easily seen how the majority of them would obtain some poison. 87 Cahxcs were anah^zed and the poison found in thcni, show inj^ that the closing of the lohes incloses some poison at least two weeks after the spra\'ino- has been done. The writer is unable to find any pub- lished record of any larva? having been found in a calyx, which were killed or supposed to have been killed by the poison. The evidence which goes to show that they are killed is all indirect. In Idaho in 1902 the writer gave special attention to this most difficult point. By examining the apples immediately after the blossom had fallen it was found that the calyx proper consisted of two parts; first, the calyx tube, which we ma}^ say is on the interior of the apple, and then the lobes or bases of the lobes which support the stamens. The stamens stand close together and form a sort of roof over the cah^x tube. The writer has man}^ times cut open this calyx tube after spraying has been done, and was unable at an}^ time to distinguish any particles of spray inside the tube. The Avriter is also unable to give any definite figures as to what percentage of the larva? enter the apple by wa}^ of the calyx tube, but it is possible that it is large. The differ- ence in percentages of larvae which have entered the calyx on sprayed or unspraA^ed trees should indicate the efficiency of the spray. Table III gives 82 per cent as entering the cah^x on sprayed trees and SO per cent on unspra^^ed trees. There was lack of data in regard to the sprayed trees, which was not discovered until it was too late to obtain a new series. Cordley finds that the larva? do not enter the fruit until two months after the petals have fallen, and on that account does not recommend the spraying immediately after the blossoms have fallen. How the larvie of the second generation are killed is a ([uestion still in a somewhat chaotic state. It is generally believed that the larva^ get the poison when they enter the fruit, l)ut the observations of many investigators, including the writer, show that when the larva* are entering they eat little or none of the fruit. In both sprayed and unsprayed orchards it is quite connnon to find places where they have entered the fruit and have died shortly after entering. Countings on 426 new entrance holes in sprayed trees showed that tluMH* was an average of 40 per cent of the holes in which tho lar\ a* had diinl, aiul in two coiuits this percentage went as high as 7<>. Other countings on unsprayed trees gave, out of ()(H) new tMitranc(\s. II pcM- cent in which the larva? had died. As there is no way i)\' knowing accurately how many of these holes were caustnl hy iar\a' whii'h entiM-ini the fruits where two a})ples touched, thest^ data can not hv vvVicd upon, but the writer believes that during the period in which the entrance holes were made at least 10 or IT) per cent of the lar\a> succumbed to the spray. Twice lar\ ;e wtM'c found di\i(l Iji^t'on^ {\\oy had entiU'ed the fruit. Alain- timers carh iii the sc^ason hol(\s \v(M-(> found, tin* making- 88 of which would employ the larvpe for several da^^s. In these cases it is questionable whether or not the spray killed the insects. In regard to the entrance of the second generation, the larvae may get some of the poison when their jaws are slipping on the fruit in the attempt to make an entrance, but at best the percentage probably killed in entering the fru^t can in no way account for the general effi- ciency of spraying. Considering the egg-laying habits and the leaf- feeding habits of the larvae of both generations, the writer is strong]}^ of the opinion that b}^ far the larger number of the larvas killed by spray are killed through eating or nibbling the poisoned leaves before they find fruits. It is to be hoped that future years will develop more definite data on this subject. THE BANDING SYSTEM. As before indicated, upon leaving the fruit the larva seeks some place in the crevices or loose bark in which to spin its cocoon. This fact was known as early as 1746, but it was not until ISttO that Bur- relle, of Massachusetts, discovered that by winding something around the tree or placing cloth in a crotch many larvte would be induced to collect there and could then be destroyed. He recommended destroy- ing them in a hot oven. The banding system was further studied and elaborated by Dr. Trimble, who recommended hay ropes for bands. Very soon this became the most successful method used, and up to about 1880, b}^ its use mau}^ fruit growers were able to save consider- abl}^ more of their fruit than before. Manj^ other observers have made studies of these bands and proved what was best in the way of material and the manner and time of application, until now it is one of the very best adjunct methods in the control of the codling moth. Generalh^ speaking, the system of banding is simph^ furnishing the larva a good place in which to spin its cocoon and killing it after it has done so. (See PL X.) The materials used for these bands may be designated as temporary and permanent. The temporar}^ bands are composed of ha}^ paper, or any other cheap material, and, after the larvae have entered the bands, are burned with the contained larvae. Permanent bands are usually of cloth; these, after the larvae are killed, are replaced on the tree. The materials for these bands are various, and it has been found that the most efficient is some dark, heavy material. Bands of thin muslin are quite inefficient. Professor Aldrich recommends brown canton flannel. In orchard practice it is found that fruit growers use almost any material, such as old clothes, burlap, and canvas. One of the most essential features of the banding system is to render all other places on the tree unsuitable for the spinning of the cocoon, thus leaving the band the only alternative. Cracks in the tree should be filled, the rough bark scraped away, and all other obstacles removed. 89 Tho ))and sliould consist of a piece of clotli loner cnoug-h to ^o around the tree more than once, and from 10 to 14 inches in width. This piece of cloth is folded once lengthwise and placed around the tree. There are many devices for holding the bands in ])lace upon the tree. The one which gives the most satisfaction, and allows the })and to be removed and replaced most readily, consists of driving a small nail through the ends of the band after wrapping it around the tree, and then nipping off the head of the nail in such a mannei" as to leave a sharp point. Su])sequent removal of the band is accomplished by simply 18.— Large apple tree properly banded for the eodliiij,' moth (original). $:'■ t^ Fk;. I'.t.— Apple tree banded, showingbands b«ith alnn'O and below a hole in the trnnk i, original). pulling the ends off the nail, and replacement by pushing them down again over it. Ordinarily one band to the tree is sufiicient in general orchard practice. ])ut in cases where the trees are large and have a number of large branches, it is advisable to put one band around the trunk and one around each of the larger limbs. (Fig. IS.) A\'here there are holes in the trees which can not be rtMuh^rcHl unsuitable for the spinning of the cocoons, it is the best tt) put bands both ai>ove and below them. (Fig. l'-^) 90 Mai\v writers have experimented upon the effect of upon the tree. LeBaron gives the following table: Table VIII. — Xumher of Jarvx caught under bands. 'eral bands Date of examination. July 28. Aug. 11. Aug. 25. Sept. 9. Sept. 23. Bands on limbs 43 83 94 31 13 21 7 15 24 9 39 33 4 Middle bands 99 Lowest bands 28 On a single tree, from July 4 to July 23, the same writer found 110 larvae under the top band and 150 under the lower band. The author states that the windfalls in ever}^ case were left as they fell. In the season of the year when a large number of the wormy apples were on the ground the lower band caught most of the larvae, while durinof Julv, when the windfalls caused bv the first o-eneration had hardly begun to fall, the larger number of larvae were caught bv the upper band. Professor Aldrich experimented upon one large tree and five bands. The tal)le made from these experiments is here given. T.\BLE IX. — Professor Aldrldi's record of hands on one tree. July— August — September— October— 7.jl5.|21. 30. *^- 12. 18. 26. 4. 10. 17. 25. 1. 8. 15. Top 2 27 32 11 20 7 8 4 4 6 2 0 20 13 1 156 Second 0 4 9 12 1 6 13 3 1 3 7 8 9 4 1 80 Third 1 4 5 12 14 6 0 6 2 3 3 13 11 6 i 8(5 Fourth 1 4 11 11 11 3 4 2 1 2 4 7 8 6 ' 75 Bottom 0 I 3 7 18 17 1 7 8 4 3 .... 8 9 7 3 97 Total 1 1" 64 64 63 23 32 23 12 1 17 .... 24 37 55 34 j 494 Out of a total of 194 larv» about 30 per cent were caught on the u])per hand, and the lower band caught more than an}^ of the inter- mediate ones. The experiment also shows that in seeking a place for their cocoons the larvae will cross several bands, and as there is no way bv which those going up the tree and those going down can be separated, no exact percentages of such can be given. Wickson found by carefulh^ conducted experiments that while 2,701: apples and pears were counted from which larva? had escaped, there were only 1,188 under the bands, or 1:1 per cent. The remaining 56 per cent either found other places in which to spin their cocoons or were destro3'ed by their enemies. The percentage of larva? caught upon a tree will depend entirely on the condition of the tree. If the tree is free from cracks, holes, and rough bark, more larva> will ])e caught; while if there are other places in which they can spin, fewer of them will go under the bands. It has been fully demonstrated that in l^adly infested orchards of the West only a comparatively small percentage of the fruit can l)e saved bv bands alone. 91 After the larvae have collected under the bands tlu^y must be killed or the Vjands will become a positive aid to the insect. The usual method of examining the bands is as follows: One end is removed from the nail and rolled back upon itself around the tree. As the cocoons, larva\ and pup^e are exposed they are cut in two with a sharp knife or crushed. Many methods have been devised })y which these bands can be collected in wagons and brought to a central place, where the}' are put in hot water, run through wringers, or somr other device used to kill the larvi\i; but in view of the fact that many of the worms will crawl out in transit, and comparatively few of them remain attached to the l)ands, these methods must give wa}' to the one described. Another important point is the length of time which should intervene between the examination of bands and the killing of the larvae. This time depends entirely upon the length of time which it takes the larva to emerge as a moth after having left the fruit. In the warmer sections of the West ut two weeks after tlie iirst wonny fruits hiwc l)een noti^d. and in south- ern Idaho is about Juiu> 1'). It is always well to apply the bands a week or so earlier than there is any necessity for. The bands should be examined every ten days and the larva^ which have collected in them killed. This makes about ten or eleven examinations of the bands in the course of the season. KxaminatiiUi ixUov the tirst week 92 in September is unnecessaiy in southern Idaho and practically all of the Pacific northwest, as veiy few moths emerge after this time. After the fruit has been picked and carried off, the bands shoidd be removed, all the larvae in them or on the trees killed, and the bands stored, because if the}' are left in the orchard they will soon rot. WHEN BANDS MAY BE USED. Bands may be used to great advantage in an orchard bearing its first crop, which is but little infested. Many growers whose orchards are more or less isolated and but little infested use the banding system as a means of control. One of these is Mr. I. B. Perrine, of Blue Lake, Idaho, who has had great success in keeping the injury in the worst infested section of his orchard down to less than 3 per cent. The most important use of the bands is as an adjunct to spraying in a badh' infested orchard when it is desired to bring the codling moth under control in that orchard, or in genei-al practice when the trees are large and the spraying can not be well done on account of either the inefficiency of the spraying machine or the height of the trees. However, the writer, by man}- extensive experiments, has clearly demonstrated that when four or five sprayings are made with the gasoline power outfit, and the spraying solution is thorough 1}^ applied at the right time, banding is unnecessary. In orchards where spray- ing is the only remedial measure used it is advisable to keep bands on four or five normal trees, killing the larv^ at stated intervals and recording the results, so that the band record may act as an indicator for the conditions in the orchard. PRACTICAL TESTS. The season's work in 1900 may be svmimed up in saying that the work accomplished simply outlined the problem of the codling moth in the Pacific northwest. In 1901 the apple crop was so unusually small that all practical tests which had been begun were abandoned, and the time devoted to a stud}" of the life history of the insect and planning a campaign for the following year. It was decided to give the recommendations of previous years a thorough practical test under actual field conditions from the fruit grower's standpoint. Some dif- ficulty was experienced in obtaining orchards in which to work. Keeping in view the idea that the codling moth is the greatest injuri- ous factor in the commercial orchard, a large amount of work was done in such orchards, the principal part in the orchard of the Wilson Fruit Compan}', near Boise, Idaho, through the kindness of Hon. Edgar Wilson, and in that of Mr. Fremont Wood. Mr. ]\[cPherson's orchard and that of Mr. David Geckler were visited frequently and observations made. There were many orchards in various localities in Avhich no measures were used against the codling moth, and these were used as checks upon the sprayed orchards. In Idaho the injury 93 b}^ the codlino- moth in 1902 was ({u'lUi viiriji})l(', as thoro had Im'cii })iit a scattcrint^' fruit crop the year before, and conse({uently a lack of insects in some localities. The orchard of the Wilson Fruit Company, which is a type of the very ))est connnercial orchards in Idaho, was planted in isO-t by Hon. Edgar Wilson, and wa.s sold l)y him to the company which is the pres- ent owner in the early spring of 1902. Mr. Wilson acted as manager for the orchard compan}' for the season, aided by Mr. W. ¥. Cash. This orchard consists of 650 Ben Davis trees, 500 Jonathan, 750 Rome Beauty, 141 Northern Sp}^, and 800 trees which were planted as Wolf River, but were subsequently ])udded to Jonathan, and have not yet come to bearing. There are three short rows of Pewaukee, and a few trees of other varieties scattered throughout the orchard. The house in which the apples were packed and the culls stored in the fall of 1901 is about 200 feet from the orchard and has always been a source of infection for it. (PI. IV, ligs. 2 and 3.) Early in the season of 19<)2 Mr. Wilson purchased a gasoline-power spra}^ outfit and prepared to give the orchard a thorough spraving. The improvements made l)y Mr. Wilson and Mr. Cash have rendered this machine one of the most efficient for this purpose. A single spraying was accom- plished in about four days, using lime arsenite with soda exclusively as a spraying solution. A})out 2,000 very heavily loaded trees were in bearing. The conditions of the previous season were such that there was an abundant supply of insects present in 1902, except in the Rome Beaut}^ section. The writer estimated in 1901 that from 4<» to 60 per cent of the fruit in the Jonathan and Ben Davis sections was infested, no late spra3^ing having been made; and the small amount of fruit in the Rome Beaut v section was all infested. No bands were used, except upon the trees left unsprayed and a ver}^ few near the apple house. The blossoms of the flonathan and Ben Davis were fully open about May 10, and had droppinl about May 20. The Rome Beautv blooms through a longer period of time, and some blossoms were observed as late as June 1. S})raying should have begun about May 19, but on account of contimied rains it was delayed until the 2od, at which time the orchard was given a thorough s])ray- ing. After two weeks th(^ orchard was again spraytnl. at about the time the first larvie were l)eginning to enter the fruit. Hy the 1st oi July about all of the larvie of the first generation had entered the fruit. Countings on the B(mi Davisand the Jonathan section ga\e an av(Mage of a little less than 1 per c(Mit infested, while the Pewauket^ trees, which were unspraycnl, had from 20 to 2(5 per cent infestinl. The Jonathan tree nearest the a])ple house had about T) \h'v cent wormy, but this percentage^ decreased rapidly in the surrounding trees. Other orchai'ds in the same condition showed from 10 to 50 ]Hn' cent wormy; while orchards in which no renunlial measures had btHMi appruHl, and in which no insects were left over from the ^•ear i>(^fori\ showed a verv 94 small percentage wormy. In the last week of Jul}^ at about the time the second generation was beginning- to enter the fruit, a third spray- ing was made; and the fourth spra3dng was made about August 8, at which time a demonstration was made to visiting fruit growers. About ten da3^s after the spraying a dashing rain washed off a consid- erable amount of the spray. Mr. Wilson and Mr. Cash did not think it advisable to make another spra3^,in view of the fact that the results already secured were so satisfactory^ that they thought it unnecessary. There is no doubt in the mind of the writer that if this spra^dng had been made the results would have been better. Harvesting Ix^gan about the second week in OcloSer, at which time the final results were o])tained. Many trees were selected earh^ in the season and the worm}' fruit upon them counted; l)ut as the season progressed the number was reduced on account of the lack of time to make the proper countings. The following table is com]^iled from the results upon six average-sized Ben Davis trees which were situated about the center of the Ben Davis section. At all times the greatest care was exercised in making these countings as accurate as possible, ever}' one of the apples being counted and no estimates made. Table X. — LifcMnJ and iion-hifesfcd (ijqtlcs on si.r spruijcd trees. Num- ber of trees. Apples oil tree. Fallen apples. Total apples. Total apples in- fested. Total Date. In- fested. Free. Total. In- fested. Free. Total. Per cent in- fested. per cent in- fested. 1 July 16 .... Aug. 22 .... Sept.4 'Nov.— .... Total Julv 10 ... . Aug. 22 .... Sept. 4 Nov — 15 2 12 153 10 29 330 83 340 112 2 25 182 3 6 19 143 1,364 1,517 39 413 452 1,998 221 11 2 ( 21 45 410 123 431 168 4.8 26 1 ! Total 1 1 171 1,107 1 1,150 66 533 599 1,777 237 13 3 Julv 16.... Aug. 22 ... . Sept. 4 Nov.— .... Total July 16 Aug. 22 .... Sept.4 Nov. — 4 10 11 167 26 10 1 37 16 7 63 26 8 41 38 12 192 977 1 1,144 37 60 97 1,241 229 11 4 12 0 4 129 32 4 133 10 165 14 io 28 Total July 16 .... Aug 22 145 1,430 1,559 36 143 179 1,433 181 10 5 4 22 17 0 30 65 46 23 63 87 63 23 93 25 26 0 Sept.4 Nov.— .... Total Aug.13 .... Sept.4..... Nov.- .... Total 12 152 168 1,228 1,396 69 197 266 1,662 237 13 6 19 7 174 19 0 50 82 16 141 101 16 191 200 1,210 1,384 69 308 1,892 209 14 95 The large amount of free fallen apples on trees No. 1 and No. '1 are due to the apples picked otf in the process of thinning. The average total per cent infested throughout the season for these trees was 13. The greatest difficult}^ was met with in obtaining an}- reliable esti- mate upon the general results from tlie orchard, for the reason that the larger percentage of the seconds and culls wei'c graded as such because the}' were small or uncolored. The Ben Davis section pro- duced 1,944 boxes of strictly first-class fruit, and the writer estimates that this was only about one-third of the total produced. In one sec- tion of the orchard there were trees in which the loss was fully 25 per cent at harvesting time, but there were man}' others in which the loss was not over 5 per cent. The writer estimates that at picking time about 10 per cent of the fruit in this section of the orchard was infested. In the Jonathan section ::!.U30 boxes of iirst-class fruit were packed, and the culls were estimated at 1-IG boxes. By numerous counts it was found that onh' about half of these were infested, which gives a total of 78 boxes of infested fruit. As a general result, about 3 per cent of the apples were found infested, and the total per- centage for this section of the orchard was probably about 5. It was found that the tree nearest to the packing house was al)out 50 per cent wormy, but the percentage diminished rapidly toward the center of the i)lock. A few trees which could not be well spraved on account of their situation with regard to irrigating ditches were more wormy than others. In the Kome Beauty section, in which there was a small crop the year previous, a total of 3, oil boxes of tirst-class fruit was packed, and it was estimated that one-fourth, or 109 })oxes. of the culls and seconds were infested, or al)out 3 per cent of the whole crop. The Pewaukee apples were practically 100 per cent infested at the end of the season. The apples were counted on an unsprayed Domine tree September 4. and 81 per cent were found infested. From experiences in other orchards with this insect, the writer believes that, had it not been for spraying, the fruit in this orchard avouM have averaged from so to 90 per cent infested. (See Pis. XIII. XIV, XV.) In Mr. Cash's orchard, which is separated from the Wilson orchard oidy by a road, it was found tiiat the Jonathans were 25 per cent infested, only two sprayings having been made. The orchard of Mr. Fremont Wood, which is a tyi)e of the lu^st of the smaller commercial orchards, was kept under observation through- out the season. This orchard c-onsists of ai)out 1,000 trees, the larger per cent of which are Jonathan. These trees were set out ;il)out 1S<»5. In 1901 the crop was small and was ahnost totally destroyed by the codling moth. In 1902 a hand-power spraying outtit was used (PI. XII, tig. 3), which was supplemented by banding. The sprayings were made about tlie same time as in the Wilson orchard. excei>t that the last spraying was afttu* the rain. al)out the middh^ oi. August, and 96 it was probably more efficient on that account. After the first genera- tion of the larvae had entered the fruit, it was found that there were not over 3 to 5 wormy apples per tree. Harvesting- was begun in October, and at that time it was found that in the Jonathan section, which consisted of al)out 900 trees, there were 4,700 boxes of first-class fruit packed. Of culls and windfalls there were about 900 boxes, of which, from numerous counts, it was estimated that about one-half, or 9 per cent of the entire crop, were infested. Mr. McPherson's and Mr. Geckler's orchards are types of old com- mercial orchards in which the trees are large and the infestation bad. It was onh' with difficult}^ that remedial measures could be applied efficiently, as preventive measures had been neglected. In both instances, on account of the height of the trees and their closeness, the sprays could not be well applied. Mr. Geckler estimated his loss as high as 50 per cent, while Mr. McPherson lost as high as 30 per cent on the same varieties. In both of these orchards there is a con- stant supply of insects from other orchards, and their control requires ?'adical application of preventive and remedial measures. Mr. J. A. Fenton estimates that his crop was only about 15 per cent injured in 1902, he having used bands and spraying. ^Ir. I. L. Tiner, who has a small orchard in the cit}^ of Boise, estimated that he saves about 80 per cent of his fruit each year. Mr. Gus Goeldner, near Boise, estimates that he saves 90 to 95 per cent of his fruit each year. In many sections of the West estimates have been made l)v fruit grow- ers in which the^^ sa}^ they save from 85 to 98 per cent of their fruit. Sometimes these estimates are obtained from countings, but more often they can not be relied upon, the fallen fruit not having been taken into consideration. The results of practical tests in these orchards show that with four or five thorough sprayings, preferably by a gasoline-power out- fit, from al)out 85 to 95 per cent of the fruit can be saved from the codling moth. By a series of applications of these measures even this margin of loss may be reduced; but the saving of 90 per cent of the fruit under present conditions may be considered a solution of the problem. RESUME AND CONCLUSION. The codling moth, which is now a cosmopolitan insect, was intro- duced into the Pacific northwest about 1880. On account of the warm climate two overlapping generations are produced, and if proper meas- ures of control are neglected the insect, under normal conditions, will infest practically the entire apple crop of man}^ localities. The preventive measures are fully as important in controlling this insect as the remedial measures. Bui. 41, D>v. of Entomology, U. S. Dept. of Agriculture. Plate XIII. Bui. 41, Div. of Entomology, U. S. Dept. of Agnc-. ture. Plate XIV. ■z. ' = O — 3 £ o - I _ > L Bui. 41, Div. of Entomology, U. S. Dept. of Agriculture. Plate XV. Clean and Wormy Apples from Tree No. 6. Wilson Orchard. Showing 8 boxes of clean apples and 1 box of wormy apples from the tree, and 1 ba.. 465. Brief account with many earlier references. Common and sometimes destructive in orchards; and records its habits in fruit rooms. 1802. De Tigny. Historic Nat. des Insectes, Vol. IX, p. 256. Largely a compilatiim from Reaumur and Roesel. Says eggs are laiil on fruit before petals fall. 1806. Bechsteix and Sc'iiAKFKNHKKc. Xatur. dor Scluid. Forstinsoktcu. Tart 111. pp. 753-755. Mostly a compilation from Koesel ami Hrahm. 1818. IltJBNER. Verz. Bekamit. Sihmott, p. 375. 6514— No. 41—03 7 98 1819. Tufts. Massachusetts Agricultural Repository and Journal, Vol. V, 364-367. Apparently the first account of the insect in American literature. Previous American writers had credited the plum curculio with the cause of "wormy apples." Records some original breeding experiments by which he was led to conclude that the cause of most of the wormy apples in Massachusetts was a moth, and not a beetle or curculio. ^ 1825. Thatcher. American Orchardist, second edition, p. 116. Records finding the worms on the trunks of trees, and therefore advises scraping off the rough bark and washing trunks with Forsyth's composition. Apparently the first notice of the insect in horticultural books, and the first one to make any recommendations fur controlling the insect. 1826. KiRBY and Spence. Introduction to Entomology, III, p. 123. 1829. Teeitschke. Die Schmetterlinge von Europa, Vol. VIII, pp. 161-163. Many references to earlier literature. Descriptions. Brief compiled account of life history. 1831. Curtis. Brit. Entom., YIII, pi. 352. 1833. "RusTicus." Entomological Magazine, Vol. I, pp. 144-146. A very good detailed account of the life habits of the insect. Eggs laid in the calyx cup. One brood. Apparently the first important article in the English literature. 1833. BoucHE. Garten-Insekten, pp. 113-114. Brief compiled descriptions and account of habits. All that can be done to control it is to collect and feed out all wormy fruit as fast as it falls. 1834. Stephens. 111. Brit. Ent. Haust, IV, p. 119. 1837. ScHMiDBERGER. In Kollar's Naturg. der schiid. Insecten, (For English translation see Loudon and Westwood's edition of Kollar, pp. 229-232, date 1840). Good general account. Two broods indicated. (He published an earlier and more complete account in his Natur. der Obst. schiid. Insecten, to which we have not had access.) 1838. Westwood. Gardiner's Magazine, Vol. XIV, pp. 234-239. Mostly a good compilation from the accounts by Reaumur and " Rusticus." One brood indicated. 1840. BuRRELLE. New England Farmer, Vol. XVIII, no. 48, June 3, p. 398. "On the Curculio." Records breeding the moth. One brood only. Apparently the first one to suggest the famous "banding" method. 1840. Ratzeburg. Die Forst-Insecten, Vol. II, pp. 234-236, pi. 14. tig. 7. Very good general account. Believes there is but one brood in North Germany, and doubts Schmidberger's account of two broods in South Germany. 1841. Harris. Insects of Massachusetts, pp. 351-355. (In the editions of 1852 and 1862 no change occurs. ) Very good general account. Only one brood indicated. 1843. Gaylord. Trans. X. Y. State Agr. Soc, p. 158. Brief account with Westwood's figure. Recommends allowing swine to run in orchard. Insect then common in New England, but very rare in the Middle States. 1844. Low. Schiidliche Insecten, pp. 239-241. Largely a compilation from Roesel, with good discussion of remedies. 1845. Downing. Fruits and Fruit-trees, p. 66. Brief account. 1846. Morris, Miss. ("Old Lady.") American Agriculturist, Vol. V, February, pp. 65-66. Good account, with original observations, and illustrated by what is probably the first original figure of the insect to appear in American literature. 1849. Cole. American Fruit Book, p. 89. Brief account. Reports it numerous in New England and along the seaboard, and becoming more common in the Middle States. 99 1850. Simpson. The Horticulturist, Vol. IV, j). 567. Brief account of breeding experiments. Two or three brrx)ds indicated. Di.scovered that a cloth in the crotch enticed many worms, and after experiment.s with wax re<'om- mends that trees be sprayed with whitewash to fill blossom end of fruits and thus prevent egg laying at this point. 1855. NoRDLiNGER. Kleineu Feinde der Landwirthschaft, pp. ;:539-.346. One of the best and most complete accounts which have appeared in tlie '.••rinair literature. Very good discus.sion of remedies. Believes it is .single broriginal obser- vations. 1875. Saunders. Report Ontario Entomological S(H'iety for 1S74, pi>. 4.3-.50. Good general account, largely compiled from LeBamn and Riley's writings. Twobnvnls in Canada. 1875. Cook, A. J. Report Michigan Pomological Society for 1874, pp. 152-1(»0. One of the best accovuits in American literature, largely based tipon original observa- tions. Records seeing the eggs, but does not describe ttieni. 1878. Thomas. Seventh Report State iMitomologist <.t Illinois, p. JtiO. Two generations indicated. 1879, Woodward. Rural Xe\v-Yi>rker. 1V1>. 8 (Vroc. West. N. Y. Hort. Soc. for 1879, p. 20). First published account of successful use of poisons ^^ I'arisgreen i against theOiHlling moth. 100 1880. Cook. American Entomologist, Vol. Ill, p. 263. Also published in 1881 in Proc. Am. As. Ad. Sci. for 1880, p. 669; and in Kept. Mich. Hort. Soc. for 1880, p. 136. Records the successful use of London purple to destroy the insect: first test of poisons made by entomologists. 1881. ScHMiDT-GoBEL. Die schad. und niitzlichen Insecten, pp. 121-122. Brief general account. 1881. Cooke. Insects injurious to California Fruit and Fruit Trees, pp. 13-19. One of the best discussions of the habits and methods of fighting it in our literature. (Practically the same account was published by the author in 1879. and again in 1883 in his book on '-Injurious Insects," pp. 102-108.) Three broods indicated. 1883. Saunders. Insects Injurious to Fruits, pp. 127-133. Very good general discussion. 1883. Chapin. Report Second Annual Convention of California Fruit Growers, pp. 17-25. Detailed account of an extensive experiment with bands and gathering infested fruit; over 15,000 moths caught in a fruit room in one season. 1883. Walton, Miss. Report Iowa Horticultural Society for 1882, pp. 199-203. Good general account, with some valuable breeding experiments. 1883. Codling moth in California in 1883. Ann. Rep. State Board Hort. Cal., p. 18. 1883. Chapin. Progress of the orchards of California during 1883. Ann. Rep. Cal. State Board of Hort., p. 12. 1883. Manning, Jacob "W. Repelling and destroying codling moth. Trans. Mass. Hort. Soc, p. 10 ff. 1883. GoDFEEY, A. N. The codling moth. Kansas Hort. Rept. for 1883. p. 91. 1883. GiLLET, Felix. The greatest pest of California insect pests, or the codling moth. In First Ann. Rep. State Board Hort. Cal., p. 72. 1883, Dec. Snow, F. H. The codling moth or apple worm. In Quart. Rep. Kan. State Board Agr. 1884. Atkins. Report Maine Board of Agriculture for 1883, pp. 356-363. One of the most important contributions to the American literature; it is based entirely upon original observations. One full brood and a partial second one indicated. 1884. LiNTNER, J. A. Apple AVorm. Country Gentleman for Oct. 30, vol. 49, p. 897. Letter from H. C. S., Crozet, Va., in reference to enemies of the worm. 1885. GiRARD. Traite d'Entomologie, Vol. Ill, pp. 714-716. Good general account. One brood. 1885. Codlin moth (in Victoria, Australia). Report of the Secretary for Agricul- ture. 1886. Crawford. Report on Insect Pests in South Australia, pp. 32-39. Good general account. 1886. "Whitehead. Report on Insects, prepared for Agricultural Department of Great Britain, pp. 62-67. Good general account. 1886. Forbes. Transactions Illinois Department of Agriculture for 1885, Appendix, pp. 26-45. Records one of the first and most carefully and scientifically conducted experiments with poison and lime against the insect. Eight applications made. 1886. GoFF. Fourth Report of New York Agricultural Experiment Station, 1885, pp. 246-248. Records one of the first carefully conducted experiments with Paris green. 1887. WicKSON. Bulletin 75, California Agricultural Experiment Station. Careful comparative experiments Avith bands and spra\-ing. 1887. Klees. Sixth Annual Fruit Growers' Convention (of California), jd. 206. 101 1887. Cook, A. J. London i)urple agaiust codling moth. Agricult. >'•.. I. **. >ept., 1887, p. 215. 1887. Forbes. Bui. No. 1, Office of State Entomologist of Illinois, 20 pp. Re.sult.s of scientific experiments with Paris g^reen. London purple, and arsenic in 1886. Comparison of one. two. and three applications. Three broods indicated. 1887-88. Claypole, E. "W. Spraying for the codling moth. 2Lst Reix)rt Hort. Soc. Ohio, pp. 212-214. " 1888. Howard. Report U. S. Department of Agricultm'e for 1887, pp. SS-115. The best and most exhaustive discussion of the insect at that time. From ft have been compiled most subsequent discussions of habits and life historj-. Colored plate. 1888. Cook. Bui. 39, Michigan Experiment Station, pp. 1-4. Results from one. two. and three sprayings, and general conclusions from eight years' experimenting with poisons. 1888. McMillan. Bui. 2, Nebraska Experiment Station, pp. 68-77. Very good general discussion of habits and especially of remedies. 1888. PoPEXOE and Marlatt. First Report Kan.«a.s Experiment Station, pp. 16.5-193. A'aluable record of careful experiments with psects,.pp. 286-290. Brief general account. 1890. Cook. Report Michigan Board of Agriculture for 1889, p. 320. Experiments to show that grass under sprayed trees may be safely fed to stock. 1890. Bos. Tierische Schiidlinge und Niizlinge, pp. 526-527. Brief account. 1891. French. Handbook of Destructive Insect*? of Victoria, part 1, pi>. 45-,'S5. Excellent general account: colored plate. 1891. Beckwith. London purple r. Paris green for the codling moth. Bui. 12, Del. Agr. Expt. Sta., p. 16. 1891. Hudson, G. V. A few words on the codlin moths {Qirpocapsd jxnnonella L., and Cacoecia ej:ces!inna Walk. ) . Proi*. New Zealand Instit. , vol. 23, pp. 56 ff. Cacoccia excessana. native to New Zealand, attacks apples in a similar way to Carpociip^a pomoneUa. 1891. Gillette, C. P. The codling moth. Bui. 15, Colorado Agr. Expt. Sta., April. 1891. Olliff, A. Sidney. Codling moth. In Agric. Gazette, New South Wales. II, no. 7, July, p]i. 385-386. 1891. Beckwith. Bui. 12, Delaware Exivriniput Station, pp. l(>-23. Comparative test of Paris green and London purple, showing slight advantiigo for the former. 102 1891. Washburx. Bui. 10, Oregon Experiment Station, pp. 1-16. Valuable record of careful experiments with poisons and bands. 1891. Gillette. Bui. 15, Colorado Experiment Station, pp. 4-18. One of the best and most accurate general discussions of habits and remedies. 1892. Thompson. Handbook to the Insect Pests of Farm and Orchard (Tasmania), Part I, pp. 34-54. Excellent general account; two broods. 1892. LoDEMAX. Bui. 48, Cornell Experiment Station, pp. 268-274. Results of careful experiments with combination of poisons and Bordeaux mixture. 1892. Olliff. Entomological Bui. 1, Dept. Agr., New South Wales. 1892. MuNSox. Kept. Maine Experiment Station for 1891, pp. 99-109. Careful experiments with poisons and important deductions therefrom. 1892. Kellogg. Common Injurious Insects of Kansas, pp. 78-80. Good general account. 1892. TowxsEXD, C. H. Tyler. Codling moth. Bui. 5, Xew Mexico Station, March, 1892. 1893. Washburx. Bui. 25, Oregon Experiment Station, pp. 1-8. Record of original observations which form one of the most important and accurate contributions to the literature of the habits of this insect yet made. The egg figured for the first time. 1893. CoQUiLLETT. Bul. 30, Division of Entomology of U. S. Department of Agriculture, pp. 30-33. Notes on life history, supposed enemies, and methods of combating the insect in California. 1893. LiXTXER. Ninth Report on Insects of New York, pp. 338-342. Detailed account of the work of the .second brood of larvae in Xew York; and a discussion of the prevalent ideas regarding the egg-laying habits of the insect. 1893. Riley. Bul. 23, Maryland Experiment Station, pp. 71-77. Very good general account of liabits, remedies, and especially ofits enemies. 1893. LoDEMAX. Bul. 60, Cornell Experiment Station, pp. 265, 273-275. Experiments to show that usually two applications of poisons are all that are necessary or profitable in New York. 1894. Smith. Entomological News, Vol. Y, pp. 284-286. Records breeding experiments which indicate but one brood of the insect at Xew Brunswick, X. J. 1894. Marl ATT. Insect Life, Yol. YII, pp. 248-251. Evidence from various sources to show that insect is usually double brooded. 1894. Sempers. Injurious Insects, pp. 57-59. Brief general account. 1894. Schillixg. Der Praktische Ratgeber, vol. 9, pp. 121-123; 133-135; 141-143. The best discussion of the insect from a practical and economical standpoint in the German literature. One brood. 1894. Goethe, R. Experiments for catching larv?e of Carpocapsa pomonella with paper rings. Bericht d. Kgl. Lehr. fiir Obst. Wein, und Garten bau, pp. 20-21. 1894. Cockerell, T. D. A. The codling moth. New Mexico Entomologist, No. 1, Apr. 21, 1894. 1894. Garmax, H. Spraying for codling moth. Bul. 53, Ky. Agr. Expt. Sta., December, 1894. 1894. Bruxer. Insect enemies of the apple trees and its fruit. Nebraska State Hort. Soc, 1894, p. 215. 1894. Washburx. Bul. 31, Oregon Experiment Station. 103 1895. ^NIarlatt. Proceedings P>ntoinological Sodety of "Washiiiirton. Vol. Til. pp. 22S-229. Suggests that Merriam's life-zones may explain aii'l determine tlic variation in and number of broods of the insect. 1895. Weed. Insects and insecticides, Second P^dition. pp. 88-89. Brief general account. 1895. Goethe. Bericht d. Kgl. Lehr. fiir Obst. Wein, und Garten})au, pp. 22-25. Records original observations (from breeding-cage experiment) on the egg and on the habits of the young larva;, with illustrations and descriptions. First definite account of these phases of the insect to appear in any foreign literature. 1895. Adkin, Robert. The Entomologist, vol. 29, p. 2. Nut-feeding liabits. 1895. Theobald, F. Y. The Entomologist, vol. 29, p. 28. Nut-feeding habits. 1895. Adkin. South London Entomological Society. The Entomologi.st, vol. 28, p. 345. Nut-feeding habits. 1895. Westwood. South London Entomological Society. The Entomologist, vol. 28, p. 345. 1895. (Barman, H. Experiments for checking apple rot and codling moth. Bull. 59, Ky. Agr. Expt. Sta., December, 1895. 1896. Smith. Economic Entomology, pp. 322-323. Good general account. 1896. Lodeman. The Spraying of Plants, pp. 252-255. Good general account. 1896. Slixgerland. Michigan Fruit Grower, Vol. V, p. 8. Paper read before Mich. State Hort. Soc. Detailed account of original observations on oviposition and tlie habits of the young larvae, resulting in the discoverj- of some new and important economic facts. (The paper also appears in Kept. Mich. Hort. Soc. for 1S96, and that portion of it relating to the codling moth in the Rural New Yorker for Jan. 30, 1897, p. 67; and in the Proc. West. N. Y. Hort. Soc. for 1897, pp. 28-30.) 1896. Bos. Tijdschrift over Plantenziekten, Vol. XII, pp. 52-74. Very good account compiled from the writings of Schilling and Goethe. 1896. LouNSBURY. Report Government Entomologist for Cape of Good Hope, for 1895, pp. 33-36. Brief account. 1897. AValsingham. Proceedings Zoological Society, London, j>- 130. Concludes that Cydia ii the proper generic name. 1897. Smith. Garden and Forest, Vol. X, p. 334. Notes peculiar differences in habits of the insect in New Jersey, and especially at New Brunswick, N. J. 1897. ScHOYEN. Notes on insects of Norway and Sweden. Bui. 9. n. s., Div. Ent., r. S. Dept. or Agr., p. 80. 1897. Slixgerlaxd, ^NI. V. New facts about the codling moth, (ianlou an