Farmers' Cyclopedia Farmers' Cyclopedia Abridged Agricultural Records IN SEVEN VOLUMES AND A GUIDE From the Publications of the UNITED STATES DEPARTMENT OF AGRICULTURE AND THE EXPERIMENT STATIONS jl compilation of such Bulletins and Reports as are Indispensable to the Practical Farmer VOLUME VI PLANT DISEASES- PREVENTION AND CURE. INSECTS AND INSECTICIDES. FUNGI AND FUNGICIDES. SEE VOLUME VII FOR COMPLETE INDEX Garden City New York DOUBLEDAY, PAGE & COMPANY 1916 Copyright, 1912 by Agricultural Service Company Washington, D. C. All rights reserved ACKNOWLEDGMENT THE WRITINGS of the following authorities were consulted or abridged, or both, in the preparation of this volume: United States Department of Agriculture. — L. 0. Howard, C. L. Mar- latt, F. H. Chittenden, A. D. Hopkins, W. D. Hunter, F. M. WeJaster, A. L. Quaintance, E. F. Phillips, D. M. Rogers. A. C. True, T. H. Kearney, W. T. Swingle, M. A. Carleton, C. P. Hartley, R. H. True. 'Alabama.— P. H. Mell, W. E. Hinds. Arizona.— T. D. A. Cockerell, A. W. Morrell, J. A. Thornber, A. E. Vinson. Arkansas. — C. F. Adams, J. L. Hewitt, Ernest Walker, R. L. Bennett. California.— C. H. Woodworth, R. E. Smith, W. A. Setchell. Canada.— R. R. Waddle, E. J. Zavitz, S. F. Edwards, Morley Pettit, H. H. Dean, R. Harcourt, F. C. Harrison, William Lockhead, T. D. Jarvis, H. L. Fulmer, C. J. S. Bethune, J. E. Howitt, J. W. Eastham, D. H. Jones. Colorado.— C. P. Gillette, W. G. Sackett, G. P. Weldon, P. K. Blinn, G. H. Glover, E. P. Taylor, S. A. Johnson, H. H. Griffin, Joseph Reed, F. M. Rolfs. Connecticut. — W. M. Esten, Charles Thorn, W. A. Stocking, C. A. White. Delaware.— C. 0. Houghton, M. T. Cook, M. H. Beckwith, C. 0. Smith, F. D. Chester. Florida.— H. A. Gossard, E. W. Berger, H. S. Fawcett. Georgia. — C. A. McLendon, J. C. Temple, A. L. Quaintance. Hawaiian Islands. — D. L. Van Dine. Idaho. — John M. Aldrich, L. F. Henderson, J. S. Burd. Illinois.— S. A. Forbes, T. J. Burrill, J. C. Blair, G. P. Clinton, A. C. Beal, J. W. Lloyd, J. S. Brooks, A. D. Shamel, E. M. East, A. N. Hume, C. S. Crandall. Indiana. — James Troop, J. C. Arthur. Iowa. — H. E. Summers, L. H. Pammel, Herbert Osborn. Kansas. — E. A. Popenoe, H. F. Roberts, A. S. Hitchcock. Kentucky. — H. Garman, M. A. Scovell. Louisiana. — J. B. Garrett, W. G. Owen, C. W. Edgerton. Maine. — Oskar A. Johannsen. Maryland. — Thomas B. Symons, A. B. Gahan, E. N. Cory, J. B. Demaree (Profs. Cory and Demaree abridged Volume VI of this series), Willis G. Johnson, C. 0. Townsend. Massachusetts. — C. H. Fernald, G. E. Stone. Michigan.— R. H. Pettit, C. E. Marshall, W. J. Beal. Vol. VI. ACKNOWLEDGMENT Minnesota. — F. L. Washburn, E. M. Freeman. Mississippi. — A. B. McKay, H. C. Thompson, W. F. Hand. Missouri. — J. M. Stedman, J. W. Clark, B. M. Duggar, George M. Tucker, C. A. Keffer, J. C. Whitten. Montana. — E. A. Cooley, D. B. Swingle, J. W. Blankinship. Nebraska. — C. E. Bessey, Lawrence Bruner, F. D. Heald. Nevada. — S. B. Doten, P. B. Kennedy, Peter Frandsen, W. B. Mack, A. A. Heller. New Hampshire. — C. M. Weed, W. C. O'Kane, Charles Brooks, Fred W. Morse, H. H. Lamson. New Jersey. — John B. Smith, B. H. A. Groth, Jacob Z. Lipman. New Mexico.— T. D. A. Cockerell, C. H. T. Townsend. New York. — J. H. Comstock, M. V. Slingerland, 0. F. Hunziker, F. C. Stewart, P. J. Parrott, C. E. Crosley, G. W. Herrick, V. H. Lowe, F. A. Sirrine. North Carolina. — Gerald McCarthy, E. I. Smith, F. L. Stevens, C. B. Williams. North Dakota. — H. L. Bolley. Ohio. — F. M. Webster, H. A. Gossard, Edmund Secrest, A. D. Selby. Oklahoma. — E. M. Wilcox, J. F. Nicholson. Oregon. — A. B. Cardley, E. F. Pernot, E. E. Lake. Pennsylvania. — W. A. Buckbout, H. E. Fulton, M. S. McDowell, J. Ben Hill. Rhode Island. — F. E. Pember, E. A. Mallette. South Carolina. — A. F. Conradi, H. W. Barre, M. B. Hardin. South Dakota.— W. A. Wheeler, D. A. Saunders, E. W. Olive. Tennessee. — H. E. Summers, Samuel M. Bain, C. E. Chanbliss. Texas.— C. E. Sanborn, 0. M. Ball, Wilson Newell. Utah.—E. D. Ball, E. S. Eichman. Vermont. — G. H. Perkins, H. A. Edson, L. E. Jones. Virginia, — John L. Phillips, W. B. Alwood, Meade Ferguson, H. S. Eeed. Washington. — A. L. Melander, W. H. Lawrence, H. B. Humphrey, Elton Fulmer. West Virginia. — W. E. Eumsey, F. E. Brooks, N. J. Giddings, A. D. Hopkins. Wisconsin.— H. L. Eussell, F. H. King, M. P. Eavenel, E. H. Far- rington. Wyoming. — N. Nelson, B. C. Buffum. TABLE OF CONTENTS Part I. ENTOMOLOGY. Page Role of Insects 17 General Description of Insects 17 How to Use This Volume 22 Annual Loss by Insects 23 Results of Insect Control 25 Relation of Insects to Disease. 26 Insects Injurious to Fruit 29 Apple 29 Pear 44 Quince 49 Peach 50 Prune 58 Apricot 58 Plum 59 Cherry 61 Barks 62 Grape 62 Strawberries 78 Blackberries 84 Raspberries 84 Currants 91 Cranberries 93 Insects Injurious to Citrous Trees 109 Insects Injurious to Nuts 130 Insects Affecting Vegetables.. 136 Asparagus ' ' 143 Beans 145 Beets 146 Spinach 146 Cabbage 149 Cauliflower 149 Celery 154 Cucumber 155 Melon 155 Hops 158 Onions 161 Parsnip 162 Peas 162 Potato 164 Radish 165 Rhubarb 165 Squash 166 Tomato 166 Page Tobacco 166 Turnip 167 Sweet Potato 168 Insects Affecting Grain 168 Insects Affecting Forage Crops 197 Insects Affecting Stored Prod- ucts 217 Insects Injurious to Sugar Cane 227 Insects Affecting Cotton 236 Insects Affecting Tobacco.... 251 Insects Affecting House Plants 256 Insects Affecting Door- Yard Plants 270 Insects Affecting Shade Trees. 279 Insects Affecting Ornamentals 279 Insects Causing the Death of Trees 309 Insects Injurious to Living Trees 311 Insects Injurious to Dying Trees 313 Insects Injurious to Conifer- ous Trees 313 Insects Injurious to Hardwood Trees 314 Insects Injurious to Forest Products 314 Insects Injurious to Crude Products 314 Insects Injurious to Unsea- soned Products 315 Insects Injurious to Seasoned Products 316 Insects Injurious to Finished Products 316 Insects Injurious to Utilized Products 316 Insects and Future Timber Supply 316 Forest Insects and Fires Re- lated 317 Forest Insects and Fungi Re- lated 317 Insect Damages — Summary . . 317 TABLE OF CONTENTS CONTROL Page Principles of Insect Control.. 318 Control of Bark Beetles 320 Control of Living Timber In- sects 323 Injuries to Dead Trees Pre- vented 324 Injuries to Tree Reproduction Prevented 324 Injuries to Forest Products Prevented 324 Injuries to Crude Products Prevented 324 Injuries to Manufactured Prod- ucts Prevented 326 Injuries to Seasoned Products Prevented 326 Injuries to Tan-bark Prevented 327 Injuries to Utilized Products Prevented 327 Injuries to Woodwork Pre- vented 327 Injuries to Other Timber Pre- vented 328 Insect Injuries to Farm Homes 328 Control of Field Crop Insects. 351 By Culture 353 OF INSECTS. Page By Mechanical Means 354 By Legislation 362 Insecticides, How Made and Used 362 Arsenicals 363 Contact Poisons 369 Lime-Sulphur Wash 379 Dusting 383 Spraying 383 Gas Treatment 385 Orchard Fumigation 386 Tents, How Used 388 Subterranean Insects 390 Bisulphid-Carbon Vapor . . . 390 Kerosene Emulsion 391 Other Treatments. . .Many Pages Remedies for Grain Insects . . . 397 General Methods 397 Heat Methods 397 Substances That Repel 398 Remedies for Storage Insects. 397 Beneficial Insects 400 Parasites 400 Predaceous Insects 401 Bees 401 Part II. DISEASES OF CULTIVATED PLANTS. Disease of Plants, What Is It?. 425 Fungi and Bacteria, What Are They? 426 Plant Diseases in General 427 Shot Hole Effects 428 Leaf Spot Effects _. 428 Fungous Coverings '. 431 Wilt Diseases 431 Seedling Collapse 431 Plant Disease Understood ... 432 Parasitic Diseases 432 Diseases Named 433 Disease Spreading 433 Protection by Parasites 434 Fungi, Classes and Nature of.. 435 Special Facts 436 Parasitic, Survival of 437 Resting Forms 438 Alternation of Hosts 439 Hosts Are Robbed 440 Fungi Effects 441 Beneficial Organisms 441 Root Nodules 441 Disease Parasites Proved .... 442 Culture Proof 442 Enzymotic Diseases of Plants. 442 Chlorosis or Panochure Disease442 Transmission of Disease by Seed 443 Parasitic Foliage Diseases 444 Insect Attacks 445 Wounds by Insects 445 Timber Preservation 446 Diseases Due to Weather 449 Causes of Plant Disease 450 Directions for Examination .. 450 Fruit Diseases 451 Apple .' • 451 Quince 464 Pear 464 Others 465 Drupaceous Fruit Diseases .. 470 Almonds 470 Apricots 472 Plum 473 Peach 475 Diseases of Small Fruits 488 Berries Generally 488 Dewberry 490 Gooseberry 491 Raspberry 491 Blackberry 491 Strawberry 493 Cranberry 493 Currant 496 Grapes 497 Diseases of Tropical Fruits... 507 Fig . 507 TABLE OF CONTENTS Page Citrous Diseases 510 Chemical Injuries 525 Disease of Vegetables 531 Asparagus 531 Bean 531 Cabbage 540 Celery 54-4 Cucumber 544 Melon 544 Gourd 548 Lettuce 548 Onion 549 Pea 554 Potato 557 Tomato 566 Sweet Potato 570 Truck Crops 572 Diseases of Grain and Forage. 576 Alfalfa or Lucern 576 Buckwheat 577 Clover 577 Corn 579 Barley 581 Blue Grass 582 Millet 582 Rye 582 Timothy 583 Oats 583 Wheat 5S5 Diseases of Staple Products... 593 Beet 593 Sugar Cane 596 Cotton '. .. 601 Flax 606 Sorghum 612 Rice 615 Tobacco 620 Diseases of Flowers 625 Begonia 625 Carnation ■ 625 Canna 629 Chrysanthemum 630 Crocus 631 Hollyhock 631 Lily 631 Pelargonium 633 Peony 634 Phlox 634 Primula 634 Page Privet 634 Rose 634 Snapdragon 637 Violet 637 Virginia Creeper 640 Plant Diseases and Their Con- trol 634 Diseases of Forest Trees 640 Beech Diseases 640 Birch 641 Elm 641 Hemlock 641 Hickory 641 Maple 643 Oak 642 Pine 642 Poplar 643 Spruce 643 Chestnut 643 Walnut 647 Diseases of Stored Products.. 652 Insect Control Measures 656 Fungicides 656 Spraying 656 Copper Mixtures 657 Bordeaux Mixtures 658 Stock Solutions 659 Insecticides 660 Dust Mixtures 661 Copper Solutions, Other .... 662 Eau Celeste 665 Sulphur Solutions 665 Resin Solutions 665 Potassium Sulphid 665 Sulphur, Pure 665 Corrosive Sublimate 666 Lime-Sulphur Wash 666 Remedies for Smut 667 Remedies Not Over-Used . . 668 Remedies for Potatoes 669 Resistant Plants 670 Soil Infesting Parasites .... 673 Soil Diseases Avoided 673 Soil Methods 674 Forcing-house Practices 675 Seed Treatments 676 Soil Treatments 576 Winter . Remedies 678 General Remedies ......678, 679 ILLUSTRATIONS VOLUME VI. Page Cherry Tree with Leaf Spot. 33 York Apple Unsprayed 33 Canker Worm 38 Leaf Miner of Apples 43 Orchard in Nova Scotia.... 51 Lesser Peach Borer 54 Peach Tree, San Jose Scale. 69 Apple Tree, San Jose Scale. . 69 Tree Covered with Tent. ... 87 Tent, with Derrick 105 Tent for Chemicals 105 Curculio Catcher 123 Curculio Wheelbarrow 123 Spraying in Hop Yard. ..... 141 High Power Sprayer 158 Peach Tree Sprayed 177 Sugar Cane Mealy Bug 195 Apple Worm, Lesser 213 Tent Caterpillar 213 Corn Root Aphis <... 213 Army Worm, Semi-Tropical. 231 Dust Gun in Use 231 Mexican Boll Weevil 242 Pump Spray in Use 249 Disinfecting on a Large Scale 249 Ben Davis Apple Blotch. . . . 267 York Apple Sprayed 267 Peach Borer at Work 285 Brown-Tail Moth 290 Eutettix on Sugar Beets. . . . 303 Grape Root Worm 321 Pear Thrips, Work of 339 Clover Head Weevil. 357 Maple Worm 357 Spotted Fever Ticks 366 Corn Root Aphis 375 Oyster Shell Scale 375 Air Pump for Spraying 384 Fumigation Tent Work 384 Page Maple Tree Defoliated 393 Harlequin Cabbage Bug. ... 411 Potato Beetle Parasite 411 Weevils on Cornstalks 429 Peach Tree Bark Beetle 447 Power Sprayer 458 Apple Blotch 458 Leaf Hoppers 465 Sugar Beets and Eutettix. . . . 483 San Jose Scale 501 Piped Rot of Oak 519 Piped Rot of Chestnut 519 Aspen Tree with Fungi 537 Pine Sawyer Channels 537 Corn Leaf Aphis 555 American Rose Slug 555 Honey Bees 555 Potato Wart Disease 566 Wheat Insects 573 Wheat with Greenbugs 573 Trees Protected from Moths 591 Hop Flea Beetle 609 Lima Bean Pod Borer 609 Larger Cornstalk Borer 609 Grape Leaf Skeletonizer. . . . 609 Horn Fly 627 Healthy Seed Beet 627 Cigar Case-bearer 636 Grape Leaf Insects 636 Pine Sawyer 636 Celery Caterpillar 636 Cranberry Spanworm 645 Terrapin Scale 645 Parasite of Grain Aphis 645 Powder Post Beetle 663 Hop Flea Beetle 663 Log and Bark Insect 663 Spraying for Codling Moth. . 663 INSECTS AFFECTING VEGETATION PART I ENTOMOLOGY. INTRODUCTION". THERE is a constant and rapidly increasing demand from farmers, horticulturists and others more or less directly in- terested in insects, or more frequently in the ravages and losses caused by them, for a book giving in a condensed form such information as is required to fight our tiny foes in an intelli- gent manner. Information of this kind in a printed form is of more utility than any number of letters that might be written, since the illustrations necessary to describe clearly any insect can not well be given in a letter. — (Minn., E. S. B. 28.) When we consider the immense numbers of insects that exist in all parts of the habitable globe the task, to give in a few printed pages even an outline of their classification, seems to be a more than futile effort. Moreover, any classification of this multitude of forms (one million species of existing insects is not an exaggerated esti- mate) must be a more or less artificial one. Geologists speak of the age of shells, of fishes, of reptiles, periods all passed long ago, and they might well call the present geological age the age of insects, because these animals outnumber all others combined. In fact insects are found in every part of the globe that man has ever been able to reach, with the exception of the oceans, where they are replaced by closely allied animals, the crustaceans. And yet, notwithstanding the abundance of insects and their almost omnipresence, how few persons are really able to give a definition of an insect? The term insect is derived from two latin words in and seco — eut into, because the body is insected or divided into rings. At one time this term was applied to the entire group of articulates or jointed animals, and consequently early writers spoke of six-legged, eight-legged, many-legged insects. Articulates or jointed animals, which by persons not familiar with zoology are fre- quently called insects are : Wood-lice or Sow-bugs, Mites and Ticks, Spiders, Harvest-men, Book-scorpions, True-scorpions, Centipedes, Thousand-legs and others not found in Minnesota. None of these animals possess the essential characters of true insects. 17 18 INSECTS AFFECTING VEGETATION At the present time we use the term insect only for those articu- lates that possess six legs, and that have their external skeleton appar- ently composed of thirteen joints or rings, which are grouped into three regions, viz : the head, thorax and abdomen. The true insects, or hexapoda, (six-feet) undergo a more or less complete meta- morphosis, possess in the adult stage wings, and breathe through a peculiar respiratory system with external openings termed spiracles. All insects are developed from eggs, with a few apparent exceptions ; plant lice, for instance, reproduce both by eggs and by budding. The body of an adult insect is divided into three regions, each with peculiar functions. The head contains the organs of vision (com- pound eyes and simple eyes), the jointed antennae or feelers, which are the principal organs of touch, smell and hearing, and the mouth- parts, organs of taste and feeding. The thorax contains the organs of locomotion — the three pairs of legs and two pairs of wings. The abdomen contains the organs of digestion, reproduction and often of defense. All insects pass through a number of transformations or metamorphoses before reaching the adult or winged and sexual stage. The first of the four principal stages is the egg. In most .Antennc Kyes let pair of Legs 1st pair at Wings Sad paieof Leg* Jnd pair of Wjnga 3rd pair of Legs Tibia Tarsus - Head < TuoMK — — •• AMomtn A Locust or "grasshopper" dissected to show divisions of body. cases this is deposited by the female upon the proper food, and is there left, to hatch without any further maternal care. In social insects, such as bees, ants, etc., the eggs are taken care of by various methods. In exceptional cases the egg is retained in the oviduct until ready to hatch, or even until it has hatched. The larva (cater- pillar, worm, maggot, slug, grub, etc.), hatches from the egg, and it is in this stage of the life of an insect that most growth is made. But as the external skeleton of an insect does not grow the space ENTOMOLOGY 19 within soon becomes too small, and the larva has to throw off this old shell and replace it by a new and more commodious one. This action of throwing off the old shell is called moulting, and the proc- ess has to be repeated a number of times before the larva reaches its full size. During the larval existence of an insect there is stored up all the material required to produce wings and organs of repro- duction, as well as to transform the other organs, as eyes, legs, etc., into their final shape. When fully grown, the larva is transformed into the third stage, or pupa (chrysalis, nymph). In this stage the insect is usually quiescent, at least apparently so, though in reality it is a very active stage, as the most wonderful changes have to take place inside the stiff and rigid pupal shell, and frequently within a very short period. After a certain time the skin of the pupa breaks open, and the fourth and final stage or imago appears, ready to per- form all the functions of a winged, sexual insect. Although these transformations seem to be very sudden, they are really nothing but continuous growth, arrested at intervals by the inflexibility of the outer skeleton. The metamorphoses of insects vary very much, and serve as the basis for separating all insects into two groups, those with a complete metamorphosis, as described above, and those with an in- complete one. A complete metamorphosis is one of the most won- derful transformations known to natural history. From an egg hatches a worm-like creature, always hungry, growing rapidly until its full size is attained, when it suddenly stops feeding, and changing to an apparently lifeless object, becomes a pupa. Remaining almost motionless in this condition it breaks open and gives forth a much larger being, possessing many organs not found before in the earlier stages, and able to fly about to mate and deposit again eggs. In a complete metamorphosis the different stages such as egg, larva, pupa and imago do not resemble each other at all. In an incom- plete metamorphosis we have no such notable changes of form. The egg hatches into a being that looks very much like the parent, being of course quite small, and lacking all traces of wings or sexual organs. This larva feeds just as ravenously, and has in conse- quence of its rapid growth also to moult a number of times, and during these slight changes in size it acquires gradually rudimentary wings, which increase in size until the adult stage has been reached. But during this whole period of growth no quiescent state like that of a true pupa appears, and the young insect resembles its parent throughout the period of growth. Butterflies are a good illustration of a complete metamorphosis, and locusts of an incomplete, The mouth-parts of insects give us also an excellent means for classifying them into three groups. One group possesses a biting and sucking mouth ; the second one contains insects which chew their food by means of a pair of horny jaws acting in a horizontal direc- tion; the third group possesses apparently no jaws, and the species belonging here are sucking insects. They obtain their food by pierc- ing and sucking by means of four bristles enclosed in a jointed beak, or fluid food by means of a long and flexible tongue. 20 INSECTS AFFECTING VEGETATION But why is it at all necessary to classify insects for any practical purpose? In reply it must be stated that we can not fight against injurious insects with any hope of success if we do not know their structure. For instance, an insect that has no mouth to bite or chew can not be poisoned, and the application of any arsenical insecticides would in most cases be perfectly useless. Nor is it enough to know the structure of the insects ; we must also know their habits and trans- formations, because this knowledge alone will enable us to apply the remedies at the proper time. In fact, notwithstanding the great progress made in economic entomology during the last ten years, we are only able to combat successfully a limited number of injurious insects by means of insecticides. A large number of others, and the most injurious ones at that, can not be reached in that manner. Time, labor and material to do so successfully would cost much more than the whole crop would be worth. The chinch-bug, locusts, and others, if very abundant, can not be fought successfully by means of insecticides. Yet this is no reason, why we should not be able to re- duce their ravages to a minimum. But without being perfectly fa- miliar with the habits of these insects, with their life-history in all and every detail, including their insect and plant foes, we can not hope to succeed. But by knowing all this we may be able to dis- cover a weak spot into which a wedge can be driven to break up their ranks. Only by attacking the weak spot of a well fortified castle is victory possible. When we consider the immense numbers of insects, and the fact that they devour every and all kinds of organized matter, it seems almost vain even to try to fight against them. All insects are not, however, enemies to man; on the contrary, the great majority are either indifferent to him, or are either directly or indirectly benefi- cial. The indifferent ones eat substances we can not or do not use; the beneficial ones eat noxious plants, decaying substances, or live in the bodies of other insects, thus purifying the air and making space for other living organisms. Without them the soil would be covered with dead vegetable matter, the now existing plants, i. e., those that are fertilized by the wind, would become smaller and smaller, because their seeds, not eaten by insects, would all have an opportunity to grow, thus crowding, dwarfing and killing each other. Without in- sects the great majority of our brightly colored flowers would not pro- duce seeds, as most of them are dependent upon the work of these animals to cause cross-fertilization. The question is frequently asked : Why is it that farmers, horti- culturists, gardeners, etc., are more troubled in the United States with noxious insects than they are elsewhere? or Why is it that more injurious insects and of different kinds are found now than for- merly? The reasons for this increase of insects, both in numbers and kinds, are not so very difficult to give. When settlements were few and widely scattered, the whole country was covered with its virginal vegetation. Plants and animals were adapted to each other, and as soon as one of them became for any reasons exceedingly numerous, natural checks in the form of enemies to such plants or animals soon ENTOMOLOGY 21 reduced them to their normal numbers. In a state of nature plants distribute themselves in such a manner that one kind never occupies the ground exclusively. Our native forests are not composed of one species of trees, but of very many kinds, in constantly varying pro- portions which depend upon the character of the soil and the needs of the different kinds of trees. The same is true of the plants that clothe our beautiful prairies. Notwithstanding the uniformity of the soil the prairies are covered here and there with different plants. Animals, and chiefly insects, depending directly or indirectly upon plants, naturally follow their distribution. When the sod of our prairies was broken to receive the seeds of plants not grown there be- fore, the soil responded freely to the new demands and yielded phe- nomenal crops. This prospective reward for agricultural toil soon attracted more and more farmers until the prairies were teeming with human beings, eager to mine the golden grains — the only form of mining that will make a people really happy and prosperous. But in cultivating more and more soil, man destroyed the finely balanced relation between the animal and vegetable kingdoms by adding a dis- turbing factor. At first but few destructive insects to the new crops were found, because they had to be introduced from elsewhere ; but as soon as they found this Eldorado — an immense area covered with the best kind of food for them — they were not slow to appropriate to themselves what was not planted for them. Insects of all kinds, but at first mainly injurious ones, will invariably take possession of fields where plants of one kind are grown upon a large scale. Insect foes of such plants will soon find their way to such fields and fix there a new home. In course of time, however, things will change for the better, simply because the foes of such newly introduced species will also make their appearance and wage war upon their old enemies. This is one reason why in the older settled parts of the globe insect outbreaks are less frequent, though they are by no means unknown. The disturbed relationship between plants and animals has there be- come re-established. Moreover a more diversified farming is the rule in older countries, and insects there do not find such an abundance of food as where their food is grown upon a very large scale. Imported insects usually become injurious because their natural enemies are left behind in the natural habitat of the pest, To enable the reader to recognize his friends and foes amongst insects the following two artificial classifications are given. Both are very simple, and the study of insects, in most cases, requires no mag- nifying glasses. It is best to compare with both classifications any insect to be located, that no errors be made. Both classifications apply only to the adult or winged insects. I. Insects with both a biting and sucking mouth : Wings with veins : Hymenoptera. Insects with a biting mouth : Upper wings horny: Coleoptera. Upper wings like pergament: Orthoptem. Upper wings with many veins: Neuroptera. 22 INSECTS AFFECTING VEGETATION Insects with a sucking mouth : All wings scaly : Lepidoptera. Only two wings: Diptera. Upper wings half leathery and half membranous : Hemiptera. II. 1. With two wings: Diptera. 2. With four wings : A. Upper and lower similar: a. All wings scaly : Lepidoptera. b. All wings naked or a little hairy : 1. Wings with numerous veins : Neuroptera. 2. Wings with few veins : Hymenoptera. B. Upper and lower wings dissimilar: a. Mouth-parts forming a sucking tube: Hemiptera. b. Mouth-parts not forming a sucking tube: 1. Upper wings horny: Coleoptera. 2. Upper wings like pergament: Orthoptera. (Bui. 28 Minn. Agr. Exp. Sta.) METHOD OF USING THIS VOLUME. To determine what insect or disease is injuring your crops and the methods of prevention or cure, first carefully note the nature of injury to the particular crop. Then secure specimens of the injured plants and look for the pest. When you find the insect, if such be the pest or the diseased portion, if no insect is discovered, go to your library, get down this volume and look in the index for the name of the plant affected. Turn to the page indicated and read carefully through that portion until you come to the description of an injury which appears to be identical to that you have in hand. Read this over carefully and apply the remedy given. Be sure to note whether any cultural directions are given, regarding the future treatment of this specific crop, that will help to insure the freedom of the plant from this kind of an attack another year. Example. — Your wheat appears yellow and is falling down badly. Examine the fallen stalks carefully. You find that at the base are several constrictions and in the sheaths are small brown bodies, like flax-seed. Going to your library you turn to wheat in- sects and find that the description of the injury by the Hessian fly corresponds to the injury in your grain. The remedy given is to burn the stubble after harvesting to kill many of the second brood; in addition, the volume tells you to plant your wheat that fall as late as possible, without endangering your grain by winter killing. This late planting prevents the second brood from depositing eggs which will hatch the following spring and injure the grain another year. In any case the remedy will be given following each insect but for a complete discussion of the formulas and methods of making and using the various insecticides, consult the sections on the prepara- tion and uses of insecticides, pages 362-399 and 656-666. ENTOMOLOGY 23 THE ANNUAL LOSS OCCASIONED BY DESTRUCTIVE IN SECTS IN THE UNITED STATES. INTRODUCTION. In no country in the world do insects impose a heavier tax on farm products than in the United States. The losses resulting from the depredations of insects on all the plant products of the soil both in their growing and in their stored state, together with those on live stock, exceed the entire expenditures of the National Government including the pension roll and the maintenance of the Army and the Navy. Enormous as is the total value of all farm products in this country, it would be very much greater were it not for the work of these injurious insects. The statistics of agricultural products for the year 1889, of the Twelfth Census, and for subsequent years gathered by the Bureau of Statistics of the Agricultural Department indicate an annual value of all the products of the farm of about $0,000,000,000. To one familiar with the work of the important in- sect pests of the different agricultural products entering into this total it is comparatively easy to approximate the probable shrinkage due to insects. The detailed consideration of such shrinkage which fol- lows indicates that they will rarely fall below 10 per cent, and in years of excessive insect damage may amount to 50 per cent or even more of the important staple products of the farm. An annual shrinkage of 10 per cent is a low estimate, which is more often ex- ceeded than fallen below, and indicates, at current farm price* a money loss of $500,000,000— the minimum vearlv tax which insects lay on the products of the farm. This total comprises, however, only losses suffered by the growing and maturing crops and annually by live stock, and does not include two very considerable and legitimate items, namely, the loss occasioned bv insect pests to farm products chiefly cereals and forage crops, in storage, and to natural forests and forest products. As shown in the consideration of these two sources of loss presented below, at least $100,000,000 must be assigned to each, making a total annual tax chargeable to insects of $700,000 000 — (Reprint Y. B. Dep. of Agr. 1904). ' ' BASIS OF ESTIMATES. Throughout this work the estimate of losses in dollars is based on the farm price of the crop actually harvested, and does not there- fore, take into account the possible reduction in value which would follow the marketing of the larger crop. While it is true that prices are regulated by production, the factor of distribution may often predominate, so that large crops in certain countries may sometimes bring good prices and small crops low prices Durino- the ten years previous to 1904, for example, the price of wheat in this country exhibited little if any relation to our own production The bumper wheat crop of 1901 of nearlv 750,000,000 bushels brought to the farmer 23 cents a bushel more than the crop of 1894, which was 300,000,000 bushels less, or but little more than half the production of 1901 ; and in 1904 the farmer received nearly U a bushel for his wheat on a crop larger than the average 24 INSECTS AFFECTING VEGETATION Some definite means of estimating losses must be assumed, and any effort to scale down these losses by reckoning possible enhance- ment of the market price in view of the conditions just cited would come more in the category of pure guesswork and be open to quit A as great objection as the plan adopted. As an offset to possibly en- hanced values due to shrinkages occasioned by insects, moreover, are certain very legitimate items of cost. A very considerable item of loss properly chargeable to insects is the annual expenditure de- voted to their control, which, except in the case of certain fruit and truck crops, has not been considered in the estimates. This amounts to a very considerable percentage of the value of the crop in the case of orchard fruits, truck crops, and such field crops as cotton and tobacco. In the case of the cereals, protection is chiefly secured by farm practices, such as rotation of crops, variations in the time of planting, etc., and this also applies, to some extent, to cotton, to- bacco, and truck crops. In estimating the losses due to the cod- ling moth, for illustration, it is shown that over $8,000,000 a year is expended in spraying apple trees, allowing a cost of only 5 cents per tree. In the case of citrus fruits the cost of gassing and spray- ing ranges from 5 cents to $1.50 per tree. Another legitimate class of losses not included in the estimate is the secondary losses wrhich necessarily result from diminished products. For example, the excessive reduction in winter wheat through the Hessian fly ravages in 1900 put a serious check upon milling operations throughout the region worst affected and caused very heavy loss in this field of industry. Similarly a shortage of cotton may so increase the values as to lead to the shutting down of cotton mills. A shortage of grains means a corresponding loss to the railroads and other transportation companies and to shippers. In other words, any material shrinkage in an important product starts a train of losses to the end of the chapter, the total amount of which is quite beyond calculation or estimate. It is believed that these omitted items of loss will make good any difference of price which might result from the larger crops if insect damage were entirely eliminated. Outside of the cash value of the crop, furthermore, is the actual material loss in products, which is absolute so far as the consumer is concerned. The im- portance of this loss will vary with the nature of the crop. With perishable products, such as fresh fruits and vegetables, the losses due to insects may be of minor importance. For example, if the apple crop were increased by 25 or 50 per cent of marketable fruit, values would probably shrink a corresponding amount, and the de- mands of consumption and the possibilities of storage be very greatly exceeded, so that there would actually be very little benefit, if any, to the producer. On the other hand, in the case of staple products of long keeping quality, as grains, cotton, sugar, lumber products, etc., the loss may be reckoned as more nearly complete, and the chief loss due to insects falls in this latter class. ENTOMOLOGY 25 RESULTS OF CONTROL OF INSECTS. Enormous as is the annual loss which may now be fairly charged to insects, it would undoubtedly be vastly greater if such pests were left absolutely unchecked and no efforts were made to limit their operations. Were it not for the methods of controlling insect pests, resulting from the studies of the Bureau of Entomol- ogy and of the official entomologists of the various .States, and the practice of these measures by progressive farmers and fruit-growers, the losses from insects would be greatly increased. Familiar illus- trations of savings from insect losses will occur to anyone familiar with the work in economic or applied entomology in this country. The cotton worm, before it was studied and the method of com trolling it by the use of arsenicals was made common knowledge, levied in bad years a tax of $30,000,000 on the cotton crop. The prevention of loss from the Hessian fly, due to the knowledge of proper seasons for planting wheat, and other direct and cultural methods, results in the saving of wheat to the farm value of from $100,000,000 to $200,000,000 annually. Careful statistics show that the damage from the codling moth to the apple is limited two-thirds by the adoption of the arsenical sprays, banding, and other methods of control, representing a saving of from $15^000,000 to $20,000r 000 in the value of this fruit product alone. The existence and progress of the citrus industry of California were made possible by the introduction from Australia of a natural enemy of the white scale, an insect pest which was rapidly destroying the orange and lemon orchards, this introduction representing a saving to the peo- ple of that State of many million dollars every year. The rota- tion of corn with oats or other crops saves the corn crop from the attacks of the root worm to the extent of perhaps $100,000,000 an- nually in the chief corn-producing regions of the Mississippi Val- ley. The cultural system of controlling the boll weevil is already saving the farmers of Texas many millions of dollars, and, in fact, making the continuance of cotton growing possible; and scores of similar illustrations could be cited. The losses occasioned by insects to farm products exhibit a wide range in different years, due, as a rule, to favorable or un- favorable climatic conditions, and also to the abundance, from time to time, of natural enemies. The result is more or less periodicity in the occurrence of bad insect years. In other words, periods of unusual abundance of particular insect pests are, as a rule, followed by a number of years of comparative scarcity. Furthermore, sea- sons which may be favorable to one insect may prove unfavorable to others, hence^ there may be not only periodicity in the occurrence of the same insect, but more or less of a rotation of the different insect pests of particular crops. conclusions. A general analysis of the insect losses for this country has been given in the introductory paragraphs. In concluding it is only necessary to emphasize again the fact that these losses, enor- mous as they are estimated to be, could be legitimately swelled by 26 INSECTS AFFECTING VEGETATION adding the secondary losses which, in the case of the great staple productions of the farm, follow any considerable shortage and ul- timately add to the cost of living for every individual, in addition to creating large commercial disturbances. Furthermore, the cost of protection from insect damage has been considered only in the case of one or two products of the farm. Another considerable in- sect tax not estimated for is the direct loss and the cost of protec- tion from domestic or household insect pests. Screening of houses against mosquitoes or flies, protection from roaches, clothes moths, and the ravages of the white ant and of various parasitic insects, are a charge on every household. The white ant in Washington, D. C, alone causes losses of thousands of dollars yearly, and it is much more destructive in southern districts. If the smaller or larger sums expended for protection from such pests were tabu- lated for the whole country, the total would probably exceed $50,- 000,000, and might be double that amount. An omission perhaps more important than any of these is the indirect loss to the produc- ing and earning capacity of communities by diseases conveyed by insects. For example, malaria and yellow fever are dependent solely on certain species of mosquitoes, and typhoid fever is commonly carried by house flies. The losses from all three of these diseases are enormous, and in the case of yellow fever outbreaks, often al- most beyond computation. With domestic animals the tick, re- sponsible for Texas fever in the South, has been estimated to cause an annual loss of $100,000,000, and other diseases of man and domestic animals will undoubtedly be shown to depend exclusively or largely on biting or other insects. In view of these omissions, it is certain that the total of over $700,000,000 annual loss assigned to insect pests in America is below rather than above the actual damage. The lessening or prevention of this loss is the problem for the economic entomologist to solve. — (Rep. Y. B. U. S. D. A. 1904.) RELATION OF INSECTS TO DISEASE. It has been definitely ascertained that malaria and yellow fever are transmitted to man by the bites of certain mosquitoes and that one of the three chief sources of the transmission of the germs of typhoid fever is the house fly. The old idea that malaria is caused by breathing the miasma or mist of swamp has been exploded. Malaria is contracted only through the bites of mosquitoes of the genus Anopheles. The dis- ease is caused by the introduction into the blood, through the bite of the mosquito, of many small one-celled animals which destroy the red corpuscles of the blood of man. In order to avoid the dis- ease, it is only necessary to avoid the bites of the insects. Mosqui- toes are bred in stagnant water mostly and can be prevented by thorough drainage, where feasible or by spraying oil on the water. Proper screening of habitations is also necessary. One of the most important of these disease-transfer relations of insects which has been demonstrated is the carriage of yellow fever by certain mosquitoes. The cause of yellow fever has always been ENTOMOLOGY 27 a mystery, and indeed it is a mystery to-day in a measure, since, although undoubtedly a disease of parasitic origin, the parasitic or- ganism itself has not yet been discovered. During the summer and autumn of 1900 and spring and summer of 1901 the work of a commission of surgeons of the United States Army demonstrated in Cuba beyond the slightest possible doubt that yellow fever is not conveyed by infecting clothing of yellow-fever patients or by con- tact with such patients or by proximity to them, but that it is con- veyed by the bite of a certain species of mosquito known as Stego- myia calopus, which abounds in regions where yellow fever is pos- sible. The bite of this mosquito, however, does not convey yellow fever to a healthy person until twelve days have elapsed from the time when the same mosquito has bitten a person suffering with the disease. It follows from this fact that by keeping yellow-fever patients screened from the possibilities of mosquito bites we can prevent the yellow-fever mosquito from becoming infected. It fol- lows further" that by preventing healthy people from being bitten by mosquitoes we can keep them free from the disease even where infected mosquitoes exist. And it follows still further that by the adoption of remedial measures looking toward the destruction in all stages of the yellow-fever mosquito we may reduce to a minimum the possibilities of the transfer of the disease. After demonstrating the fact, the medical officers of the Army in Cuba put these meas- ures into effect, and the results were most gratifying. The health of Havana immediately improved, and the general health of Cuba and the industrial conditions dependent upon better sanitation have continually gained since. The New Orleans outbreak of yellow fever in the summer of 1905 was quickly stopped by antimosquito measures, and it is con- ceded that more than 4,000 lives were saved in that city during that season by the intelligent application of measures based upon the discovery of the United States Army surgeons in Cuba in 1900 and 1901. TYPHOID FEVER. The principal insect agent in this spread is the common house fly, and this insect is especially abundant in country houses in the vicinity of stables in which horses are kept. The reason for this is that the preferred food of the larvae of house flies is horse manure. House flies breed in incredible numbers in a manure pile, largely derived from horses. Twelve hundred house flies, and perhaps more, will issue from a pound of horse manure. Ten days com- pletes a generation of house flies in the summer. The number of eggs laid by each female fly averages 120. Thus, under favorable conditions, the offspring of a single over-wintering house fly may in the course of a summer reach a figure almost beyond belief. With an uncared-for pile of horse manure in the vicinity of a house, therefore, flies are sure to swarm. Their number practically will be limited only by breeding opportunities. They are attracted to, and will lay their eggs in, human excrement. Under favorable conditions they will breed, to some extent, in this excrement. The5 28 1XSECTS AFFECTING VEGETATION swarm in kitchens and dining rooms where food supplies are ex- posed. They are found commonly in box privies, which sometimes are not distant from the kitchens and dining rooms. Therefore, with an abundance of flies, with a box privy near by, or with ex- cremental deposits in the neighborhood, and with a perhaps un- suspected or not yet fully developed case of typhoid in the immedi- ate neighborhood, there is no reason why, through the agency of contaminated flies alighting upon food supplies the disease should not be spread to healthy individuals. That it is so spread is not to be questioned. That under the unusual conditions of the army con- centration camps in the summer of 1898 it was so spread to a shock- ing extent has been demonstrated by the army typhoid fever com- mission. And the remedy is plain. It consists of two courses of procedure: (1) Proper care of excreta; (2) the destruction of flies. On many farms where intelligent people live the old-fashioned box privy has been done away with, and there has been substituted for it some form of earth closet. Where a good earth closet is in operation, and the inhabitants of a farm appreciate the importance of using no other, and where in case of illness the excreta of patients are promptly disinfected, flies breeding in the neighborhood will have practically no opportunity to become contaminated with ty- phoid germs, except in the unlikely event (which future investi- gation may possibly show) that other animals than man are sub- ject to this disease. The proper maintenance of an earth closet will add somewhat to the work of a farm, but this extra work will pay in the long run. While it is true that a box inclosure, if its contents are covered with lime every three or four days, will answer the pur- pose, a much better plan would be to use a large metal vessel, the surface of the contents being covered with earth after each opera- tion, and wThich may be removed, emptied, and replaced daily. Care should, of course, be taken to empty the contents of the vessel in a pit constructed in some well-chosen spot, from which the drain- age would not be dangerous. With regard to the abolition of flies, the best measures will again naturally involve some trouble and expense. In a thickly set- tled country it will become necessary for some such measure to be generally adopted in order to be perfectly effective, but in an iso- lated farmhouse the number of house flies may be greatly reduced by individual work. All horse manure accumulating in stables or barns should be collected, if not daily, at least once a wreek, and should be placed in either a pit or vault or in a screened inclosure like a closet at the side or end of the stable. This closet should have an outside door from which horse manure can be shoveled when it is needed for manuring purposes. Each day's or each week's accumulations, after they are shoveled into the closet or pit, should be sprinkled over the surface with chloride of lime, and a barrel of this substance can conveniently be kept in the closet. If this plan be adopted (and these recommendations are the result of practical experience), house flies will have almost no chance to breed, and their numbers will be so greatly reduced that they will hardly be ENTOMOLOGY 29 noticeable. Many experiments have been made in the treatment of manure piles in order to kill the maggots of the house fly, and the chloride-of-lime treatment has been found to be the cheapest aud most efficacious. It has been stated above that the closet for the reception of manure should be made tight to prevent the entrance or exit of flies. A. window fitted with a wire screen is not desirable, since the corroding chloride fumes will ruin a wire screen in a few days. — (Farmers' Bui. 135.) INSECTS INJURIOUS TO FRUIT. APPLE INSECTS. The Woolly Aphis. — Throughout the summer on the lower por- tion of the trunk and particularly on the water sprouts of the apple may often be seen small bluish-white flocculent or cottony patches, which indicate the presence of colonies of one of the worst enemies of the apple, viz., the insect variously known in this country as the apple-root plant-louse, woolly apple-louse, woolly aphis, etc., and abroad very generally as the American blight. It exists in two forms, tne one just referred to, above ground on the trunk or water shoots, and another inhabiting the roots and not open to observation. Closely paralleling in these particulars the grape phylloxera, the damage from the woolly aphis is also almost altogether "due to the root form, the aerial colonies causing scarcely any injury. On the roots its attacks induce enlargements or galls or swellings very similar to those produced by the phylloxera, and in the cracks of these galls and swellings the root form occurs in clustered masses. The injury to the trees is due both to the sucking up and exhaustion of the vital plant juices and to the poisoning of the parts attacked, as indicated by the consequent abnormal growths. The woolly-aphis of the apple is found in nature in two so-called forms. One" infests the limbs and twigs, while the other lives under the ground upon the roots. The presence of the aerial form of the woolly-aphis is readily detected by the bluish-white cottony or downy looking substance that is excreted, by and covers the greater part of each wingless individual aphis; and since these insects live in clusters or colonies, the patches of white matter are very conspicuous, and can scarcely escape the no- tice of even the most casual observer. — (Mo. E. S. B 35- DeDt of Agr. Cir. No. 20, B. E.) ' ' The presence of the root inhabiting form is readily detected by removing the earth from the roots near the trunk of the infested tree. The appearance of a bluish-white cottony or mildew looking substance, or of knotty and distorted roots will indicate its presence. It is this root or subterranean form that causes so much damage to the apple orchards in the southern half of Missouri, and to apple nursery stock throughout the state. The infested' apple tree appears sickly; it does not grow as it should; its leaves are less numerous and they have more of a pale green or yellowish color than is nat- ural ; and finally the tree dies outright or is blown over with the first slight wind. 30 IX SECTS AFFECTING VEGETATION The woolly-aphis sucking the juices from the roots of the apple tree causes an abnormal growth of the attacked portion of the roots resulting in the formation of gall-like swellings or excrescences. These swellings are usually irregular and knotty in appearance and sometimes attain considerable size, while that portion of the roots between the excrescences is frequently undeveloped. After planting, if the trees be kept in vigorous growing condi- tion by careful cultivation and, if necessary, proper fertilizing, dam- age from the aphides is much less apt to occur, and the principal danger period, namely, the first two or three years after planting in the orchard, will pass in safety. The value, as a means of protec- tion, of thorough cultivation and good care of young orchards can not be too strongly insisted upon. Vigorous growing trees have a decided power of resistance and are able to sustain with compara- tively little damage the presence of the root-aphides, while illy-cul- tivated and neglected orchards are especially liable to injury. In planting apple trees tobacco dust should be freely used among and over the roots, and close around the trunk, in order to kill and prevent the woolly-aphis from establishing itself there. The root form of the woolly-aphis may be cheaply and easily killed and kept away from an apple tree by the liberal use of to- bacco dust. About five or six pounds of this substance should be applied as above directed to the roots of every infested tree, and one- half this amount should be applied in a similar manner each suc- ceeding spring, costing approximately two cents per tree per year. The other sprays may be used after the trees are in full leaf in the following proportions: Kerosene emulsion that is one-fif- teenth kerosene; fish oil and whale oil soaps in the proportion of 1 pound to 8 gallons of water, and tobacco decoction in the proportion of 1 pound to 4 gallons of water.— (Col. E. S. B. [Press] 31; Mo. E. S. B. 35; Dep. of Agr. B. of E. Cir. 20.) The Round-Headed Apple-Tree Borer. — The first intimation that the grower may have of the presence of this borer in his trees, unless he be forewarned, is in their retarded growth and the saw- dust-like castings, consisting of excrementitious matter and gnawn- ings of woody fiber, which the larvse extends from the openings into their burrower. The parent of this borer is a beautiful beetle, measuring from three-fourths to nearly an inch in length. The upper surface is light yellowish brown with two longitudinal white stripes extending through the thorax and elytra or wing-covers to the tip. The larva, when mature, measures from three-fourths to a little over an inch in length. This borer is practically limited in its food to the apple and kindred woody plants. It is most in- jurious to quince and apple, and somewhat less so to pear. This species inhabits more particularly the base of the trunk of trees, often being found below the surface of the earth, especially in young nursery stock. The larvae, soon after hatching, tunnel under the bark and feed on the sap-wood, gradually working their way upward and afterwards downward, usually remaining withjn a short distance of. or below the surface of the ground, particularly ENTOMOLOGY 31 in young trees. One-third the larvae gnaw outward to the bark * * * and issue through a round hole as mature beetles. — (32 3rd Revise U. S. Dept. Agr.) Any one of several washes in general use against boring insects may be used as a deterrent. A good alkaline wash is prepared of soft soap reduced to the consistency of thick paint by the addition of caustic potash or washing soda in solution. A good fish-oil, or whale-oil, soap, or common soft soap, is often used, and in some cases any one of these is sufficient to deter the insects from deposit- ing their eggs. After borers have once entered a tree there is no better remedy known than to cut them out with a knife or other sharp instrument. In the treatment of this insect an ounce of pre vention is worth several pounds of cure. The Flat-Headed Apple-Tree Borer.— The adult of the flat- headed apple-tree borer is a bettle measuring about one-half inch in length, the upper surface of a dark metallic-brown color and the under surface of a coppery bronze color. The larva differs from the round-headed borer in that only a single year is required for its development, pupation occurring in the spring shortly before the appearance of the bettles. It differs, also, in its manner of work, living for the most part just beneath the bark, where it excavates broad, flat, and very irregular channels. Its name, flat-headed borer, is derived from the peculiar flat expansion of the second thoracic segment — which is close to the head. In color it is light yellow and in length measures nearly twice that of the mature insect. This borer attacks diseased or dying trees by preference, inhabits all parts of a tree from the base of the trunk to the limbs, and is not restricted to fruit trees, but attacks a variety of deciduous trees, also. Infestation may be detected by the discoloration of the bark. A list of the recorded food plants of this borer includes, among or- chard trees, apple, pear, and peach. When the borers have entered the tree, they may be destroyed by cutting them out or by killing them in their burrows with a pointed wire, if they were not too deep or too far from the point of entrance. The best wash for borers, all considered, is made by the union of all the ingredients in the following way: Dissolve as much com- mon washing soda as possible in six gallons of water, then dissolve one gallon of ordinary soft soap in the above and add one pint of crude carbolic acid and thoroughly mix; slake a quantity of lime in four gallons of water so that when it is added to the above, the whole will make a thick white-wash ; add this to the above and mix thor- oughly, and finally add one-half pound of paris green or one-fourth pound of powdered white arsenic and mix it thoroughly in the above. The remedies advised for the round-headed borer are also of value and are generally employed against the present species. It is nec- essary, however, that deterrent coverings and washes should be ap- plied farther up the trunk and to as many branches as can be con- veniently reached. Careful, clean methods of orchard management are essential as a measure of protection, and involve the cutting out' 32 INSECTS AFFECTING VEGETATION of dead, dying, and injured deciduous forest and shade as well as orchard trees known to be chosen as food by this species. — (Ga. Bui. 44; Mo. Exp. Sta. 14; Bui. 47 Ariz. Exp. Sta.) The Fruit-Tree Bark Beetle.* — Injury to the peach by the fruit- tree bark-beetle is usually first indicated by the exudation of gum from the trunk and branches, forming numerous globules, and later by the presence in the bark of numerous small round holes, as if the tree had been peppered with shot. As a rule, only trees in a weakened or sickly condition are attacked, but injury to apparently healthy trees has been observed. The insect causing this trouble is a small cylindrical beetle, about one-tenth of an inch in length, and about one-third as wide. Closely examined, it is seen to be uni- formly black in color, except a portion of the legs and the tips of the wing covers, which are dull red. In this country the fruit-tree bark-beetle attacks various vari- eties of the plum, cherry, apricot, nectarine, peach, apple, pear, and quince. The adult insects perish each fall, the winter being passed by the larvae within the infested tree; and these transform to adults which emerge from the tree usually about the latter part of March. The adult beetles make minute holes through the bark, and they and their larvae mine or burrow just beneath the bark thus destroy- ing the cambium layer and killing the limb above. While the fruit- tree bark-beetle is almost sure to attack first of all unhealthy, in- jured or dying trees or parts of trees, they will attack and injure apparently perfectly healthy trees. This bark-beetle is much more difficult to control than other fruit-tree borers, but may be success- fully held in check by careful attention to the following : Clean cul- ture is of first importance ; every tree or part of a tree that is badly infested or is dying from any cause whatsoever should be removed and burned at once. The trees should be kept in as healthy and vigorous a condition as possible by cultivation and fertilization. We have found the best wash to be the following: Dissolve as much common washing soda as possible in six gallons of soft water, then dissolve one gallon of ordinary soft soap in the above and add one pint of crude carbolic acid and mix thoroughly ; two pounds of lime is then slaked in two gallons of water and filtered so as to re- move all dirt and small lumps; this is now added to the above and mixed; while to all is added one-half pound of paris green or one- fourth pound of white arsenic, and thoroughly mixed. — (Bui. 44 Mo. Exp. Sta. ; Cir. 29 B. E. U. S. Dept. Agr. ; Year Book, U. S. Dept, Agr. 1905.) The San Jose Scale. f— Probably the most serious single pest to the deciduous fruits in this country is the Pernicious, or San Jose Scale. A tree when badly infested with the San Jose Scale pre- sents a somewhat grayish appearance as if it were coated with ashes, but to the ordinary observer the tree would hardly seem to be in- fested unless very closely examined. However, if one should at- tempt to scrape the bark it would be seen to be covered with numer- * For illustration, see page 447. tFor illustrations, see pages 69 and 501 Cherry Tree with Leaf-Spot Disease Sprayed with Self-Boiled Lime-Sulphur Mixture. Dept. of Agr. Unsprayed York Imperial Apple Tree Almost Defoliated by Leaf-Spot. Dept. of Agr. ENTOMOLOGY 35 ous little scales of varying sizes, beneath which lies the small, oval, orange colored, jelly-like objects which are the true insects. If an adult female insect is closely examined, a small grayish circular scale about one-twenty-fourth of an inch in diameter, the center of which is convex forming a slight nipple will be seen ; also numerous concentric circles can be seen around the nipple the scale developing by additions to the outer edge. The scale of the male is somewhat elongated. Beneath the scale is the true jelly-like individ- ual. The color of the scale is variable. In the half mature insect the scale is nearly black with a central gray nipple and one or two grayish rings, but it gradually becomes entirely grayish when ap- proaching the adult state. The San Jose scale passes the winter in an immature condition fixed to the bark of the host plant, the small, dark-gray or blackish scales being just discernible with the unaided eye. As has been already stated the San Jose scale, in the absence of proper treatment, will quickly bring about the death of most plants of economic im- portance. When safety, cost and efficiency are all considered, we believe lime-sulphur is the best remedy for the orchardist to use. It can be used very liberally with little or no danger to the trees and, by its color, indicates within a few hours whether the spraying was thoroughly done. No particular difference has been observed in the effectiveness of the lime-sulphur wash, whether applied in the fall or early spring, during the dormant season. It is believed, however, that early spring- is the best time to spray, as the mixture will remain on the trees for a longer period during the summer, when the scale is breeding, and this is desirable. Certain manufacturers have put on the market concentrated solutions of lime-sulphur wash, which have only to be diluted with water for use. These commercial washes have proved to be about as effective in controlling the scale as the well-cooked lime-sulphur wash", and, although somewhat more expensive, have been adopted by many commercial orchardists in preference to the home-prepared spray. — (Pop. Ed. Bui. 193 and 194, N. Y. Agr. Exp. Sta.; Bui. 148, Md. Exp. Sta.; Cir. 129, B. of E., U. S. Dept, Agr. ; Cir. 64, Ohio Agr. Exp. Sta. ; Press Bui. 48, Col. Agr. E. S.) The Oyster Shell Scale* — This insect has received the common name "oyster-shell scale," owing to the resemblance of its scale or covering to a long, narrow oyster shell. The adult female scales are about one-eighth of an inch in length, usually brown to dark brown in color, though occasionally they have a grayish appearance which is due to bleaching over winter. On account of its size, the scale is not conspicuous unless in large numbers. The scale adheres very closely to the bark of the tree, and resembles it very much in color. During the winter, it shelters the eggs. A cheap and very satisfactory remedy for the oyster-shell bark- louse is kerosene emulsion, applied shortly after the emergence of the young. This is about May 1st for latitude corresponding to Washington, D. C. * See illustration on page 375. 36 INSECTS AFFECTING VEGETATION Kerosene emulsion stock solution, 60 per cent oil, is made after the following formula: Kerosene (coal oil, lamp oil) 2 gallons. Whale-oil or laundry soap (or 1 quart soft soap).% pound. Water 1 gallon. The soap should first be dissolved in boiling water; then re- move vessel from the fire. Immediately add the kerosene, and thor- oughly agitate the mixture until a creamy solution results. The stock emulsion may be more conveniently made by pouring the mix- ture into the tank of a spray pump, and pumping the liquid through the nozzle back into the tank for some minutes. The stock solution, if well made, will keep for some months, and is to be diluted before using. In order to make a 10 per cent spray (the strength for trees in foliage) add to each 1 gallon of the stock solution about 5 2/3 gallons of water.— (U. S. Dep. Agr. B. E. Cir. 12; B. 64 Del. E. S.; Tenn. E. S. Vol. X.) The Scurfy Scale. — The female scales are somewhat irregu- larly oval or pear-shaped in outline, whitish in color and measure about Vs of an inch in length. These scales may occur singly or in considerable numbers, forming irregular patches in which case the shape of the individual scales is not readily made out. It is from these scurf -like patches that the insect derives its popular name. Like the oyster-shell bark-louse the winter is passed in the egg stage. The scurfy scale, while infesting a considerable number of plants, is a less general feeder than is the preceding species. It occurs prin- cipally upon rosaceous plants, such as the apple, peach, pear, plum, cherry, etc, and also on currant and gooseberry among cultivated plants, but seldom becomes so abundant as to cause particular in- jury or to require specific treatment. Inasmuch as the life-history of this species is quite similar to that of the oyster-shell bark-louse the treatment for the latter species is equally applicable to this. The point to be remembered is to keep a close watch to see when the young begin to appear and then to spray within a few days, before they have had time to form scales which would protect them. — (Bui. 64 Del. Exp. Sta.; Cir. 121 B. of E. U. S. Dept, Agr.) The Codling Moth. — This is the parent of the worm which causes the wormy apple. The average adult has an expanse of wing of about three-quarters of an inch. The general color of the front wings is dark gray and of the hind wings light brown. Out near the tip of each front wing, as the photograph shows, there is a well marked brown patch which shows golden when the light falls on it. The fact that the moth closely resembles the bark of the tree in its coloring and being nocturnal in its habits, is, no doubt, why so few fruit-growers become familiar with the adult insect. The moth itself is harmless to the fruit. It passes the winter as a larva (worm) in a cocoon in any good hiding place, such as under the loose bark on trees. These larva? begin to transform into pupae, and soon after the apple blossoms have fallen the moths begin to emerge. The eggs laid by these are placed chiefly on the leaves, and require on an average 9 or 10 days to ENTOMOLOGY 37 hatch. Usually it is about 3 weeks after the blossoms fall before the earliest eggs have hatched. On hatching the young larvae seek an easy place to enter the apple. This the calyx furnishes, and 75 per cent or more of these first brood larvae enter the fruit by this part. The best spray mixture to use is 2 lbs. of arsenate of lead to 40 gals, of Bordeaux mixture, or dilute commercial lime-sulphur. The Bordeaux or lime-sulphur is added to control the scab fungus, as this is the most important time to spray for this disease. The Bordeaux need not be stronger than the 3.3.40 formula, and the lime-sulphur may be diluted 1 gal. to 40 gals. Paris green or arsenite of lime may be used with Bordeaux mixture instead of arsenate of lead, but with lime-sulphur arsenate of lead is the only arsenical poison that is safe. Two methods of control, differing in the kind of spray used, are general; one is known as the Western, the other the Eastern method. By the Western method spray your trees with arsenate of lead, using one pound to fifty gallons of water. Begin to spray when 80 per cent, of the blossoms have fallen, and have enough outfits on h*nd to be through in eight days. Use Bordeaux nozzles only, be- cause they throw a coarse penetrating stream, and do not use more nozzles than the capacity of your pump will supply and still keep the pressure up. Set the nozzles at an angle of 45 degrees by means of an elbow coupling. Throw the spray directly into the throat of every flower. To reach the bottom of the flowers much pressure is absolutely necessary. Do not spray at less than 80 pounds, and if possible use 200 pounds or more. By the Eastern method use arsenate of lead of any good brand at a strength of ope and a half to two pounds of the arsenate to fifty gallons of water is preferable. The time to apply the first spray is determined by the condition of the calyx of the bloom. This time is following the dropping of the petals but before the closing of the calyx. A period not to exceed from five to seven days for any one variety would cover the time when this first spraying should be "done. Use a nozzle that gives a fine mist such as the Friend or Mistry, Jr. Under cultural methods we include not only cultivation, but also keeping the dead scales of bark scraped off the trees, pruning, and burning the rubbish which naturally accumulates in the orchard, keeping fallen apples picked up and either used or destroyed. — (Press Bui. 42, Col. Exp. Sta, ; Bui. 65, N. Mex. Exp. Sta,; Bui. 142, Md. Exp. Sta. ; Bui. 187, Ont. Dept, Agr. ; Bui. 142, Cornell Exp. Sta.; Pop. Bui. 30, Washington Exp. Sta.) The Apple Maggot or Railroad Worm. — The parent insect that lays the egg from which the railroad worm hatches is a two-winged fly, about the size of the common house fly. It looks much like the house fly except that its wings have dark zig-zag marks on them. The railroad worm is hatched from an egg laid beneath the skin of the fruit From July to October is the lime of year to fight the apple maggot or railroad worm. The way to do this is to keep the infested apple from rotting beneath the trees. This can be accom- 38 INSECTS AFFECTING VEGETATION plished either by picking up the drops every few days, or by main- taining enough livestock beneath infested trees to keep the drops cleaned up. The Apple Red Bug. — The adult Red Bug is about }4 inch long. The general color varies from red to nearly black ; usually the thorax is black in front and red behind. The wings are red, usually black along the inner edge and with a pointed ovate black spot near the outer margin. The principal injury is caused by the punctures in the young fruit. The apples are then very small and the four sharp bristles of the bug's back penetrate quite to the center. The results of our experiments show that the young nymphs may be killed by an application of Black-leaf tobacco extract diluted 1 to 65, or Black-leaf 40 diluted 1 to 800 — that is, about 1 ounce in 6 gallons of water or % pint in a barrel of 50 gallons. The efficiency of this spray is increased by the addition of about 2 pounds of soap to each 50 gallons. The majority of the eggs of the Red Bug hatch after the opening of the leaves of the fruit buds and before the blossoms open. The first application should be made just before the blossoms open and while the nymphs are small, soft, and tender. — (Bui. 101, B. of E. U. S. Dept. Agr. ; Cir. 14, New Hamp. Exp. Sta. ; Bui. 291, Cornell Exp. Sta.) Plum Curculio. — This pest infests the apple, causing a great many knotty apples. (For description see the Plum Insects.) The Apple Plant Louse. — The insects appear with the foliage, and where they are at all numerous the leaves begin to curl, and growth is checked in early summer. The aphids excrete a sweet, sticky liquid. The females are of a uniform velvety green, sluggish in motion, and rather more than one-twentieth of an inch in length. The males are smaller, much more active, and dull yellowish-green in color. The eggs are large in proportion to the insects, dark-green in color when laid, becoming black in two or three days. They are regular, rather elongate-oval in shape, and smooth, shining. The apple plant louse hatches from the egg as soon as the buds begin to develop in early spring. In about fifteen days a stem-mother be- comes developed and begins to reproduce. Sprav with Black Leaf 1-65, or Black Leaf 401-840, or 10% Kerosene Emulsion.— Bui. 193, N. J. Exp. Sta.) The Canker Worm. — Two species of canker-worms in the United States, the spring canker-worm and the fall canker-worm, are often very troublesome pests in apple orchards, infesting also the elm, cherry, and to a less degree, a few other trees. The life history and habits of the fall canker-worm practically parallel those of the spring species. The females of both species are wingless, hence their dis- semination is very slow. These canker-worms are green or brown, more or less striped with longitudinal lines. Just back of the head are six legs with pointed claws, and near the posterior end of the body are four or six other legs, different in form. When the cater- pillar crawls the middle of the body assumes the shape of a hump or loop ; on account of this these insects are called looping caterpillars or measuring worms. Work of Canker-Worm: i. Egg Mass on Bark; 2. Larvae; 3- Pupae; 4- Fkmale Moths .Male Moths; 6. Work of Canker-Worm on Apple Leaves When Wl;'75' Later Work. '(Figures i to S Enlarged; 6 and 7 Reduced.) Dept. of Agr. ENTOMOLOGY 39 Orchardists having canker-worms to contend with may confi- dently expect to practically eradicate them in the course of one or two seasons by following the methods above described, namely, thor- oughly spraying the trees with a strong arsenical and thoroughly plowing the ground during the summer. If Paris green is used, this should be applied at the rate of 1 pound for each 100 gallons of water, and unless used in Bordeaux mixture there should always be added the milk of lime made from slaking 4 or 5 pounds of good stone lime. Arsenate of lead may be used at the rate of 6 to 10 pounds to 100 gallons of water or Bordeaux mixture, and because of the strength at which it may be used without injury to foliage and its excellent sticking qualities it is to be preferred to other arsenicals for canker-worms. Another important method of protecting high orchard and other trees which it is impracticable to spray is the em- ployment of special protectors, such as bands of cotton, or sticky substances.— (Bui. 68 Part II, U. S. D. A. B. E.; Bui. 44, New Hamp. Agr. Exp. Sta.) The Apple-Tree Tent Caterpillars. — These are dull reddish- brown, stout-bodied moths, with a wing expanse in the females of about 1.5 to 2 inches, and in the males of from 1.2 to 1.3 inches. Obliquely across the forewings of each sex are two nearly parallel whitish lines, as shown in the illustration. The conspicuous and unsightly nests or tents of this insect are familiar objects in the spring. The caterpillars feed upon foliage of the trees, stripping the leaves from the limbs adjacent to the nest. The favorite food of the tent caterpillar is the wild cherry, and this is probably its native food plant. Next to the wild cherry the apple is apparently preferred. In the absence of its favorite food, or under special conditions, it attacks many other plants, as plum, peach, thorn, pear, rose, and other members of this group ; also beech, witch-hazel, elm, maple, various species of willows, oaks, and pop- lars, etc. Eggs are deposited in masses or belts encircling the smaller twigs. The unsightly nests are especially apt to be found on wild cherry, apple, and other trees growing along roadsides, fences, and elsewhere. In most cases such trees could doubtless be removed with- out disadvantage, and their removal would greatly reduce the num- bers of this pest by lessening their favorite food supply. Tent cater- pillars are readily destroyed by arsenicals sprayed on foliage of trees infested by them. The caterpillars are killed in from two to three days by the use of Paris green at the rate of 1 pound to 300 or 400 gallons of water. Orchards or trees sprayed with arsenicals in the spring for the codling moth, canker-worms, or .similar insects will be kept practically free from tent caterpillars. — (Cir. 98 U. S. D. A. B. E.) The Fall Web-vmrm. — The common Fall Web-worm is so named because of the web which it spins over its food plant in Au- gust and September, somewhat resembling that made by the Tent Caterpillar in the spring, with which it is often confused. The moths are of a pure white color, the wings expanding an inch to an iO INSECTS AFFECTING VEGETATION inch and a quarter. This species is practically the only common moth which might be mistaken for the Brown-tail Moth, which is also pure white except the bushy brown tail, while the body of the fall web-worm moth is white. Rarely, however, the fall web-worm moths have the wings spotted more or less with black. The young caterpillars, which seem to be almost all head and hair, at once com- mence to spin their web over the foliage upon which they are feed- ing. Within this web the colony from an egg mass feeds, enlarging it as it becomes necessary. The webs are usually started at the tips of limbs and are to be first noticed about August 1st. When the food in the webs become scarce the older caterpillars scatter over the tree where food is more abundant, and as soon as full grown seek a place in which to spin their cocoons. The full grown caterpillars are about an inch long and quite woolly, being thickly covered with long white and black hairs, which project from numerous prominent black tubercles. When the caterpillars are first noticed at work on the tips of the twigs, if they seem to be abundant, it is best to spray the tree with an arsenical. Arsenate of lead, five pounds to the barrel of water, is best, though Paris green, at the rate of one pound to 100 gallons, with a pound or two of freshly slacked stone lime is equally effective, but does not adhere as well. It is useless to wait until the tree is covered with large webs and then spray. To be effective the tree must be sprayed early in August soon after the eggs hatch. As it is also advisable to spray at this time for the young brown-tail moth caterpillars, it will be found to be good practice to spray about this time every year. The Yellow-Necked Apple Caterpillar. — During August one often notices the tips of the apple limbs defoliated for a foot or two. If examined for the cause of the damage either the Yellow-necked Apple Caterpillars or the next species to be described, the Red- humped Apple Caterpillars are found huddled together as if confess- edly guilty. The larvae become full grown during the latter half of August, five or six weeks after hatching from the eggs. The caterpil- lar is then about two inches long with jet black head, and the next segment, often termed the neck, a bright orange yellow, from which the insect is named. Down the middle of the back runs a black stripe, and on either side of the body are three stripes of black alternating with four of yellow, the body being thinly clothed with long, soft, white hairs. The caterpillars feed together in colonies and are often tound clustered together on a limb in a, solid mass. If the limb bear- ing it is jarred or if a caterpillar is touched, it at once assumes a po- sition characteristic of this genus, throwing the head and tail in the air with a jerk and clinging to the limb by the abdominal prolegs. — (Bui. 139,' New Hamp. Exp. Sta.) The Red-Humped Apple Caterpillar. — With much the same habits and manner of injury as the last species and often associated with it, is the Red-humped Apple Caterpillar. The name is given on account of the prominent hump on the fourth segment, which, with the head, is a bright coral red. The body of the full grown caterpil- ENTOMOLOGY 41 lar is striped with yellowish-white, and dark brown or black lines and a double row of black spines extends along the back. The back is marked with five narrow black lines. The full grown caterpillar is about an inch and a quarter long and tapers toward the posterior end which is usually held in the air. The caterpillars appear about the same time in August and defoliate the limb from the tip inward the same as the Yellow-necked Apple Caterpillar. These caterpillars are also gregarious and are often found hud- dled together in masses on the limbs. When handled a caterpillar will emit a fluid which has a peculiar acid smell and which doubtless serves as a defense against its enemies. The caterpillars also feed on plum, rose, thorn, pear, cherry, willow, blackberry, and other related plants. As the work of these caterpillars is very quickly noticed and as they habitually feed together in colonies, it is an easy matter to hand pick and destroy them, or swab them off the limbs with a rag or waste saturated with kerosene. When a colony is noticed at the tip of a limb it may be cut off and burned, though this is rarely neces- sary. If this and other caterpillars are common upon the terminals it will be well to spray the trees about August 1st with arsenate of lead, three to five pounds per barrel. To be most effective this should be applied while the caterpillars are still small. The White-Marked Tussock Moth. — This caterpillar is recogniz- able by its bright red head and by the velvety black back, on which there are four thick tufts of creamy colored hair, looking like round paint brushes. At either end is a pair of long, black, plume-like hair pencils and there are shorter tufts of hair along the sides. In general, the caterpillars give the impression of being yellow, with black and bright red markings. In the winter the eggs may be easily removed and destroyed while pruning the trees. Where apple or- chards have been sprayed with an arsenical, such as Paris green or arsenate of lead late in May, in the usual manner for the codling moth and diseases, there will be little trouble with the first brood, and probably but few of the second. Should the second brood appear nu- merous spraying about August 1st, as for the other apple caterpillars described, will destroy them. Summary. — The fall web-worms, yellow-necked apple caterpil- lars, red-humped apple caterpillars, tussock moth caterpillars, and hickory tiger moth caterpillars injure apple foliage in late summer. They may be controlled by spraying with an arsenical insecticide about August first. As it is also desirable to spray for the brown-tail moth at this time, an early August spraying may well be made a reg- ular orchard practice, for which directions are given herein. — (Bui. 139, N. H. Exp. Sta. ; Bui. N. J. E. S.) Green Fruit-Worms. — From time to time, green worms, about the size of cut-worms, are to be seen working on fruits. The writer has usually found them on apples and once on strawberry. They are apple-green or light-green in color and have three light-yellow- ish stripes running the entire length, one line on the back and one on each side. Sometimes there are additional markings which are 42 INSECTS AFFECTING VEGETATION quite variable. They eat holes in the young fruit and foliage. They are said to work on a number of trees and shrubs, including most of the fruits grown in Michigan, feeding during the day and probably also during the night, and dropping to the ground when disturbed. The pupal stage is passed in earthen cells in the ground. Professor Slingerland, who discusses these creatures at length, says that the insects are very difficult to kill with the ordinary late sprays, but that trees sprayed before they blossom, with the arsenites and bor- deaux are apt to be pretty free from them. As the insects are pe- riodic in their invasions, often disappearing for a number of years together, it is not possible to foretell just when such a spray will be necessary. Those who apply bordeaux before the buds open, as a regular practice, may find it a paying investment to add a little poi- son for this insect, the bud-moth, and several other pests. Professor Slingerland also recommends jarring in the same manner as for curculio. The Cigar Case-Bearer *—This very interesting little creature is occasionally so numerous as to cause injury to apple and pear. The larva makes a case in a manner similar to the resplendent shield- bearer. This little case resembles a minute cigar about one-fourth of an inch long. It is very carefully described by Professor Slinger- land in Bulletin No. 93 of the Cornell University Experiment Sta- tion. The larva is said to make two cases during its lifetime, one in the fall, curved and very small, and one in the spring in which the pupal stage is passed. It attacks the buds as they swell, and later feeds on fruit and foliage reaching out from the case and mining under the skin of the leaf. The adult is said to be steel grey in color and spreads less than half an inch from tip to tip of its wings. It may be controlled by early sprays of paris green, applied when the buds open, and also at the time when the trees are sprayed for the codling moth. Usually it will be found expedient to add. the poison when spraying with Bordeaux for the scab, thus reducing the ex- pense.— (Bui. 24 Mich. Agr. Exp. Sta.) The Pistol Case-Bearer. — This insect is a moth of a general dark drab color. The larva is the destructive form and lives within a case. The cases are of a dark brown or black color, more or less covered with grayish pubescence from the leaves. Their form is aptly de- scribed by the word pistol-shaped. A careful examination of one of these moving pistol-shaped objects will reveal its inhabitant^ an or- ange-colored, black-headed caterpillar about one-fourth of an inch in length. Thus the insect has quite a wide range of food-plants, in- cluding three orchard fruits, apple, cherry, plum, and probably the chestnut. Beginning on the swelling buds, the case-bearers continue their destructive work on the opening leaves and flowers, showing a decided preference for the flowers. The pest can be controlled by spraying twice before the buds open with 1 lb. Paris green to 200 gals, of water or a fungicidal solution. The Palmer-Worm. — This pest does all of its destructive work in the caterpillar stage of its life. Even when full grown, this * See illustration on page 637, Work of Trumpet Leaf-Mixer of Apples; Larvae Broods ix Apple Leaf. Dept. of Agr. ENTOMOLOGY 43 palmer-worm is quite a small, slender caterpillar, measuring only about half an inch in length. It general color is olivaceous or brown- ish-green, lighter on the underside, and usually with a light-brown head. The body is striped with 4 narrow white lines. The palmer- worm moth is a minute gray or brownish-gray insect measuring across its expanded wings only a little more than % inch. This insect appears at irregular intervals in great numbers, doing con- siderable damage in the territory where it occurs. It feeds on apple, plum, cherry, and oak. The codling moth sprays will keep the insects in check on apple and the annual poison sprays on plum and cherry for curculios will answer on those trees. — (Bui. 124 and 187 Cornell Exp. Sta.) Apple Leaf-Miner. — Many fruit-growers have observed small, brownish patches on the leaves of apple trees. These patches are caused by a minute insect which feeds on the internal tissue of the leaf. The insect is the larva of a small gray moth. The mines are sometimes so numerous that as they increase in size they run together and form one large blotch covering the greater part of the leaf. As the epidermis of the upper surface of the leaf dies it loses its elas- ticity, and a curling of the leaf inward is the result. The leaves at this stage cease to perform their functions and soon drop. The higher branches of the tree are usually more seriously affected and lose their foliage first. This loss of foliage results in premature, un- dersized fruit. By checking its vegetative activity the vitality of the tree will also be more or less reduced. In view of the fact that the insect feeds entirely on the inner tissues of the leaf, the application of arsenicals or contract insecticides is useless for the control of this pest. The gathering up and destroying of the leaves in the fall read- ily suggests itself, and is recommended where tillage is not practiced. There are, however, so many insects of various species which spend part of their existence in the ground and which are destroyed by breaking up their quarters, that, aside from the generally recognized benefits, orchard tillage is, in most cases, recommended. The Bud-Moth. — Early in the spring, just as they commence to swell and open, the buds of apple and pear and sometimes those of plum, cherry, quince, and peach trees, are occasionally attacked by small, almost naked caterpillars, about a fifth of an inch long, and dirty white in color, the head and thoracic shield being black or very dark brown. The caterpillars feed on the opening buds, later bind- ing the young leaves and blossoms together with silken threads. In- side the rrest thus fonned, the larvae feed and attain the length of nearly three-fourths of an inch, change to pupae and finally to adult, winged moths, which usually emerge here during the last of June, or first part of July. The eggs are soon laid and the larvae hatched, the young larvae feeding on the under side of the leaves and skeletoniz- ing them. When partially grown, they spin small nests or hiber- naculi, in protected places, and remain until the following spring, when they attack the buds as described. The best remedy is to spray with arsenicals just as the buds open. Cover the buds with poison, and the young larvae will be killed 44 INSECTS AFFECTING VEGETATION early in their career. Sometimes more than one application is neces- sary, but be sure to hit each bud with the spray. The presence or ab- sence of the little nests later will indicate the success or failure of the application. — (Bui. 45 Conn. Exp. Sta.; Bui. 24 Mich. Agr. Exp. Sta.) The Buffalo Tree-Hopper. — A small green insect, three-eighths of an inch in length, triangular in form, and shaped somewhat like a beechnut, but having the prothorax extending above the head in two horn-like growths. They sometimes weaken the twigs of apple by laying their eggs therein. The wounds so made are slow to heal, and on young trees may be the cause of injury through the breaking off of the twigs. No remedy is known except the cutting out of the eggs during the fall and winter. — (Bui. 24 Mich. Agr. Exp. Sta.) The Plum Cureulio. — (See Plum Insects). PEAK INSECTS. The European Pear Scale. — This pest, which is commonly known in California as the Italian pear scale, closely resembles to the naked eye the San Jose scale (Aspidiotus perniciosus Comst.), but can be readily distinguished from this species by the form of the male scale which is a great deal longer and carinated. Furthermore they can be separated by the manner of working. The European pear scale, in California, probably works only under cover of the lichens on the trunk and larger limbs, and apparently does not work on the twigs or younger branches as does the San Jose scale. Distillate-oil emulsion at 6 per cent strength and crude-oil emulsion at 12 per cent strength, measured by their efficiency against scales and lichens, convenience of preparation and application, and cost, are the sprays best adapted for the European pear scale. All sprays, to insure the best results, should be applied with a power out- fit at a high pressure (180 to 200 pounds). A coarse, drenching spray applied with crook nozzles is preferable, and February is the best month in which to spray. The Howard Scale. — Individual insects are of very minute size, being smaller than a pin head. They are of yellowish- orange color, covered by a pale grayish scale secretion. For the greater part of the insect's life it is motionless upon the bark or fruit. The winter is passed in an immature stage. In the spring, winged males appear, and early in the summer young insects are hatched from eggs laid beneath the female scale covering. These crawl about for a short time, finally settling down, the females to remain motionless for the rest of their lives. Slightly infested trees will exhibit only inconspicuous grayish dots. Badly infested trees have a grayish appearance over their bark, much as if a layer of ashes covered the tree. When rubbed, this gives the surface a greasy or buttery appearance, caused by the crushing of the bodies of myriads of the yellow parasites hidden un- der the scales. It is most common upon pear, prune, plum, and al- mond. The Bartlett is the most susceptible variety of pear grown in the Grand Valley. ENTOMOLOGY 45 The lime and sulphur sprays prove to be superior from the standpoint of effectiveness and cost. They are to be recommended to the use of fruit growers as the most valuable spring spray for trees still dormant. Besides being a contact insecticide of high value against other fruit tree insects, it is also valuable as a fungicide. — (Bui. 80, Part VIII, B. of E. U. S. Dept, Agr.; Bui. 30 Col. Agr. Exp. Sta.) The Pear Thrips* — Injury to the various fruit trees by this spe- cies is caused by the feeding of the adults on the developing buds and early blossoms, by deposition of eggs into the fruit stems, leaf stems, and newly formed fruit, and by the feeding of the larvae in the blossoms and on the young fruits and foliage. On pears the greater injury is produced by the adults, which often prevent the trees from blooming, wThile on prunes and cherries the larvae fre- quently prevent a crop of fruit from setting after the trees have come into full bloom. Also, the deposition of eggs into the fruit stems of prunes and cherries so weakens the stems that much of the young fruit falls. The feeding injury is not produced by a biting or chew- ing process. By rasping the tender surfaces in the developing fruit buds and the young fruits with their hardened or chitinous mouth- parts, the thrips rupture the skin, causing an exudation of sap wThich is often followed by more or less fermentaion, especially before blooming. The feeding by larvae on prunes after blooming causes the wTell-known thrips "scab," while most of the scarred and mis- shapen pears are caused by the work of the adults. The adults or winged form of the thrips first appear on the trees about the middle of February and emergence from the ground continues till early April, maximum emergence, however, occurring in late February and early March. The pear thrips is in some re- spects an unusual insect in that it remains in a dormant or semidor- mant condition for about ten months of the year. Although on the trees for only two months out of the twelve, it is able in this short time, in the absence of treatment, to completely destroy all prospects of a crop of fruit, in many cases within a very few days. The trees are attacked at the period of bud swelling and blossoming, when they are most susceptible to injury. These minute insects come literally in swarms, and may, if left alone, completely destroy all of the fruit buds of an orchard in four or five days. Many cases have been known where a delay of four or five days in spraying resulted in loss of the entire crop of fruit, and in some cases half of all the buds were killed in three days after the thrips appeared on the trees in great numbers. In view of this condition it is very evident that any means of control must be very thorough and done in the most exacting manner at the proper time.— (Cir. 131, B. of E. U. S. Dept, of Agr.; Bui. 68, Part X, Revised B. of E. U. S. Dept. Agr.) Spraying is by far the most common and the most satisfac- tory means for controlling the pear thrips on all classes of deciduous fruit trees in California. Only the most efficient spray materials should be used, namely, the combination of distillate-oil emulsion and tobacco extract or distillate-oil emulsion and nicotine solutions. *Sce illustration on page 339. 46 INSECTS AFFECTING VEGETATION The spraying must be thoroughly done and put on the trees when the thrips appear in numbers, not waiting till many buds have been destroyed. It is strongly advised to use power machines, and grow- ers are urged to use them for all the spraying, and to have a tower platform elevated over the tank so that one man can thoroughly drench the tops of the trees. It is absolutely necessary to use high pressure — from 150 to 200 pounds — and only angle nozzles should be employed, and these must be held close to the bud clusters to force the spray directly into the ends of the buds. This is absolutely necessary to secure good penetration and get satisfactory results. Plenty of material — 3 to 5 gallons per tree for pears, depending on the size of the tree — should be used ; more liquid is required for large prune trees ; large cherry trees may require 7 to 8 gallons per tree for satisfactory results. In badly infested orchards three applications are necessary the first year for controlling the pear thrips. Two of these sprayings should be directed against the adults and one against the larvae, and to obtain satisfactory results must be timed properly. The first spray- ing should come as soon as the thrips can be found on the trees in numbers. The second spraying, which is also for adults, should come from four to ten days after the first, depending somewhat on variety of fruit, stage of bud development, and rapidity of emergence of thrips from the ground. On pears this will usually be just as the earliest cluster buds are spreading, and on prunes and cherries when the tips of the petals first begin to show. Both of these applications are important and necessary to insure the production of a good crop of uninjured blossoms. The nozzles should be held close to the bud clusters and the spray directed into the ends of the buds. This makes it necessary that the spraying be done mostly from above. The third spraying is for larvse and properly comes just as most of the petals are falling from the trees, depending somewhat upon the variety of fruit. Those who can do so successfully are advised to irrigate and plow in the fall. This is to be followed by thorough spraying the following spring.— (Cir. 131 B. of E. U. S. Dept. Agr.) The Pear Psylla. — Occasionally we hear of trouble arising from the pear psylla, an European insect, which was first noticed in Mich- igan in 1891. The presence of this insect is usually indicated by a general loss of vitality in the tree, early in the season. The young growth droops, and sometimes considerable foliage and fruit drop from the tree. The leaves are seen to be smeared with honey-dew, which attracts ants and wasps, and which supports a black, sooty fungus later in the season. The immature insects are very small, a little more than one-six- teenth of an inch in size, yellow at first but afterward becoming marked with black and red. They hatch from the eggs in May and immediately commence sucking the juice of the leaves. The secre- tion of honey-dew is so copious that the insects soon become sur- rounded by small puddles of this sticky liquid, in which they sit and grow. In about a month, they change to the adult, winged form,^ in which stage they are provided with wings, and with strong jumping ENTOMOLOGY 47 legs. When disturbed, they jump and fly away, sometimes being so numerous as to appear to fly in droves. Several broods are reared in one season. Spray with weak kerosene-emulsion while the insects are in the immature condition in late May and early June. At this time they cannot fly. Any of the strong winter washes should prove all right as they pass the winter hidden away in cracks and crannies and under the buds. Clean culture will also prove useful, for judging from allied species, many adults will be found to pass the winter in rubbish. The Pear-Leaf Blister-Mite. — About the time when the young pear leaves become full grown, and while they are still tender, they sometimes are disfigured by pinkish, thickened patches, involving a portion of the leaf, or occasionally the entire leaf. As the leaf be- comes firmer in texture, the patches become darker, finally appear ing black and corky. A thin slice through such a thickened, corky patch, shows, under the microscope, a cavity connecting with the out- side by a small opening. In the cavity may sometimes be found the cause of the mischief; minute, white mites, elongate in form, and so small that a glass is required in order to be sure of them. These little mites are the cause of the thickened growth or gall, and the conse- quent injury to the foliage. Sometimes they form galls in the young fruit as well. Oftentimes the foliage falls, and the fruit fails to amount to anything. The mites pass the winter tucked away under the bud scales. As the mites are concealed, during the growing season, in the galls of the leaves, it is useless to spray during that period. In the winter, however, they may be killed by a spray of strong kerosene- emulsion applied while the buds are dormant, or at any rate before they open in the spring. — (Bui. 24 Mich. E. S.) The Pear Slug. — The damage to the foliage of the pear, cherry, plum, and allied trees from the slimy slug-worm is familiar to every fruit grower. Two or three generations of these slug-worms, or slugs, as they are also termed, appear during the summer and frequently in such extraordinary numbers, with the later broods, that the leaves of the attacked plants turn brown, die, and fall to the ground in mid- summer, and the new growth of foliage which is afterward thrown out is often similarly destroyed. The slug-fly is a small, glossy black insect, considerably less in size than the house fly, measuring only about one-fifth of an inch in length. The wings, which are four in number, «are transparent, iridescent, and have a smoky band across the middle, which varies in intensity in different specimens. It be- longs to the family commonly termed saw-flies on account of the saw-like instrument or ovipositor with which the female insect places its eggs in the leaves or other soft parts of the plant. At first it is clear or free from slime and in color nearly white, except the yellow- ish-brown head; but almost immediately the slimy or gluey olive-col- ored liquid begins to exude over its entire body, giving it the appear- ance of a minute slug, or soft snail, from which it gets its name. Its head is dark brown, appearing black under the slime, and the 48 IX SECTS AFFECTING VEGETATION body also becomes almost equally dark. The anterior segments are much swollen, covering up and concealing the head and thoracic legs. As soon as the larva emerges from the egg it begins feeding on the upper surface of the leaf, eating out small holes or patches about the size of a pinhead or smaller, but never eating entirely through the leaf. The larvae feed almost invariably on the upper side of the leaves and the minute eaten spots which they make at the start rap- idly increase in size until much of it, but not the entire surface of the leaf, is denuded, leaving merely a network of veins, or a leaf skeleton, held together by a nearly intact lower epidermis. The best means of destroying the slug-worm is to spray the plants with an arsenical wash or with a simple soap solution. The larvae are delicate and easily killed, and as they eat almost exclu- sively on the upper surface of the leaf where the poison can be most easily placed, they get the greatest amount of it and are the easiest of all larvae to be thus exterminated. The plants may be sprayed with Paris green or other arsenical wash at the rate of 1 pound of the poison, mixed with an equal amount of lime, to 250 gallons of water. The soap wash to be effective must be applied at a strength of one- half pound of soap to a gallon of water, first dissolving the soap, preferably whale oil, by boiling in a small quantity of water. — (Cir. 26 U. S. D. A. B. E.) The Codling Moth on Pears. — The pear crop of California suf- fers much from injury by the codling moth, and in view of the com- mercial importance of this crop, the losses represent in the aggregate a large item. The injury is especially important on green fruit des- tined for shipment to eastern markets, but even in the case of drying stock there is without doubt an important deterioration in quality. For description of the insect and its life history see the Codling Moth under Apple Insects. There are practically two full broods of larvae in the pear-grow- ing districts of the interior counties of California. Comparatively few of the first-brood larvae go over the winter. The number of first- brood larvae being relatively small, the injury is not so noticeable, and many growers overlook the importance of destroying this brood of worms to prevent the greater damage by the more important sec- ond-brood larvae, which begin to enter the fruit just prior to the first picking. The first-brood larvae begin entering the fruit about a month after most of the petals have fallen, though this time may vary somewhat with the season. All spraying for the first brood should be done within three to four weeks after the blossoms are off the trees. Two, and preferably three, treatments are advised, using ar- senate of lead at the rate of 4 pounds to each 100 gallons of water. The first application should be made as soon as most of the petals have fallen, and especial pains should be taken as nearly as possible to fill each calyx cup with the poison. The trees should be drenched. The second treatment should come three to five weeks after the fall- ing of the petals. The third application should be given nine or ten weeks after the falling of the blossoms, or about two weeks before the ENTOMOLOGY 49 first picking begins. If only two treatments can be given, the first and second of the above schedule should be given. See the Apple Insects.— (U. S. D. A., B. E. Bui. 97, part II.) QUINCE INSECTS. A Quince Mealy-Bug. — A quince orchard near Geneva was found to be infested, early in April, with numbers of little plant- louse-like bugs. Nearly all of the trees showed some of the tiny, powder-covered, soft-bodied, wingless bugs; but none of them were so infested as to be perceptibly injured. These bugs are quite similar in structure and feeding habits to the plant lice; but unlike the lice, they are produced from eggs, and their mature form is not unlike that first hatched, except that the larvae at first are pink in color, while the adults are white from their covering of powder. The eggs are laid along in late June and early July, and are placed in a dou- ble-walled cocoon of silk. As these bugs are soft bodied and live openly on the twigs dur- ing spring and early summer, they can easily be controlled by spray- ing with whale-oil soap solution, 1 to 5. The arsenites would have no effect, as, like all bugs, these meal-coated ones draw their food from beneath the surface. "Where there is loose bark, scraping the trunks and branches to uncover the insects and egg cocoons, and painting the wood in winter with strong whale-oil-soap solution will be of benefit.— (Bui. 24 Mich. Agr. Exp. Sta.) The Quince Curculio. — Like all beetles, this quince curculio passes through four different stages during its life — the egg, larva or grub, pupa, and the adult or beetle. It is injurious to the quince in two of its stages. The beetles sting the fruits, forming many of the familiar knotty places, and wormy quinces are the work of the grubs or larvae. Quince growers should thus familiarize themselves with these two stages of the insect. The other stages — the egg and pupa — are discussed later on in connection with the story of the life of the pest. The beetle is somewhat larger than the common plum curculio, has a comparatively longer snout, and is very broad-shouldered. Its general color is of a rather uniform brownish gray, mottled more or less with white, especially on the thorax. The larva is a fleshy, maggot-like, footless grub of a semi-trans- parent, light flesh color. Its head is dark brown, with the horny jaws darker, and there is a lighter brown, shield-like area on the back of the first thoracic segment. The long dreary months are spent by the grub in a little earthen cavity or cell two or three inches below the surface. After leaving the fruit in the fall, the grub burrows its way into the soil and there forms its winter home by rolling and twisting its body around and thus packing the earth back, leaving a small, oval, smooth-walled cell in which its winter nap is undisturbed by the elements above. With the warmth of the spring-time the grubs begin their des- tined transformations necessary to complete their life cycle. Won- derful changes take place beneath the grub's skin which is finally cast off and a form, quite unlike the grub, known as the pupa appears. From 10 to 20 days are spent by this insect in the spring 50 INSECTS AFFECTING VEGETATION in this quiescent pupa stage in its earthen cell. Finally the pupal shroud or skin is cast off and the active adult or curculio appears. For a week or more after they emerge from the ground in the spring, the curculios feed upon the growing quince fruits, and pos- sibly to a slight extent upon the leaves. After feeding on the fruit for about a week, as described above, the beetles copulate and soon begin laying eggs. The eggs hatch in from seven to ten days, and the little grubs at once begin eating their way into the fruit. The grubs continue feeding in the fleshy part of the fruit for about a month, forming therein a large worm-eaten cavity. With our present knowledge of its life and habits, the jarring process is the most successful method for fighting the quince curculio yet suggested and tested. Those who practice the jarring method successfully, jar the trees every day, if possible, from the time the beetles appear until their numbers decrease beyond the danger point, or only a few are captured each time. This jarring process involves considerable labor and expense, but experienced fruit growers tell us it costs only from 15 to 20 cents to jar a tree during the season. One should consider that this slight expenditure may often favorably de- cide the important question of a large crop of fine fruit or a meager crop of knotty and wormy fruit. The insects of the quince are prac- tically the same as those of the apple. — (Bui. 148 Cornell Agr. Exp. Sta.) PEACH INSECTS. The Black Peach Aphis. — The black peach aphis infests the roots, tender shoots, and foliage of the peach, causing more serious injury when occurring on the roots. Its presence on the roots is often unsuspected, the failure of the trees being attributed to other causes. Young trees recently planted are most subject to injury, before they have become well established in the soil. Infested trees may fail to grow off well, at the end of two or three years being scarcely larger than when planted. The foliage assumes a yellowish green, sickly appearance, the leaves becoming somewhat curled on the edges and blotched with red, suggesting a wet soil or incipient yellows. The insects occur in two forms — winged and wingless — the for- mer occurring only on the shoots and leaves, while the latter occur on both the foliage and roots. An individual aphis is quite small, the body in both forms averaging about 2 mm. in length, shining jet black or dark brown in color, oval in shape, though the body of the wingless form is stouter. The young are faint greenish-brown in color, gradually becoming darker as they grow, till the jet black con- dition of the adult is reached. They feed by means of a beak, which is thrust into the tissues of the plant, and the sap removed by their combined attack constitutes a serious drain on plant vitality. The insect lives on the roots of the plant during the entire season, and breeding is continuous, except during the winter, which is spent in hibernation. The aphides are usually attended by ants, which aid them in securing food, transporting them from place to place and otherwise caring for them. In the spring the aphides make their way above the ground and begin to feed and breed on the tender EXTOMOLOGY 53 growth just pushing out. During summer the aphides for the most part are to be found on the roots, though a few may be found on the foliage and shoots in badly infested orchards at almost any time dur- ing the growing season. Below ground they occur more or less pro- misculously on roots of all sizes, but the smaller and more tender ones are preferred. Some of the aphides may retain their hold on the roots after the trees are dug, and the insect is thus frequently distributed on nursery stock. Heavy dressings of kainit, according to Dr. J. B. Smith, are effectual in killing the aphides. The fertilizer should be applied over the ground covering the root area of the tree, preferably just before a rain. Unleached wood ashes, from one-half to one bushel per tree, is recommended by Pettit as being very effective. It is better to first remove the soil over approximately the root area of the tree, replacing it after the ashes have been applied. Ground tobacco dust may be used in the same way. In all of these substances the insecticidal properties leach out, coming in contact with the soft bodies of the aphides on the roots and thus killing many of them. Aerial forms may be killed by "Black Leaf" 1-60.— (Year Book 1905, Dept. Agr., "The Principal Insect Enemies of the Peach.") The West Indian Peach Scale. — The female scale is 2 to 2.5 mm. or .08 to .10 inches in diameter, quite convex and usually gray^ ish white in color. The scales are often inconspicuous from being covered with a thin layer of the skin of the outer bark. Again they stand out conspicuously white against the natural color of the plant they infest, naked, glossy and smooth. The male scale is pure white, exuvia pale straw color. Length 1 to 1.5 mm. or .04 to .06 inches. The male scales cluster together in dense chaffy patches, preferably on the lower parts of the branches of young trees, and on the trunk near the ground giving the impres- sion of a coat of whitewash at a distance from the tree. A scattering male scale can generally be found here and there among the females. The adult male is a minute, two-winged insect, bright red in color, with darker head and pale legs. The treatment of orchards and rem- edies advised in the control of the San Jose scale will be equally effective in the control of this species. — (Bui. 61 Fla. Exp. Sta. ; 1905 Year Book, U. S. Dept. Agr.) The San Jose Scale. — Under normal conditions the San Jose scale can kill a young orchard in ihree years if the infestation is brought in with the nursery stock. If it gets in later, the older trees resist better and less injury is caused. Very old and rough-barked trees sometimes resist perfectly and at the present time, the scale has lost some of the virulence of its early days. In no case, however, should the presence of this scale be lightly esteemed in a peach or- chard, for even a single favorable season of unrestricted breeding may irretrievably injure its trees. (For a complete description and remedial measures see page 32.) The Terrapin Scale* — The Terrapin Scale is one of the soft or naked scales, the outer covering being a hardened portion of the derm and not a wax secretion combined with cast skins, as is the case » See page 645, for illustration. 54 INSECTS AFFECTING VEGETATION with the San Jose Scale. This scale insect can be most easily identi- fied during its hibernating winter stage. The scale is hemispherical in form and at this time is about 2 mm. in length and slightly less in width, mottled brown, with radiating streaks of black toward the sides, and an orange red patch on the top, the sides being more or less ridged. Sometimes individuals will be observed to be entirely red or black. As the females develop in spring, the size increases and at full growth the scale is about 3 mm. in length and of nearly uniform reddish brown color. The eggs hatch about June 1 and the larvae im- mediately crawl to the leaves, usually on the under side. They re- main here for a period of two months, then return to the twigs to winter. From the above results we recommend that a standard miscible oil be employed at a strength of 1 to 15, applied on the trees just as late in the spring as possible before the buds open. In cases of slight infestation, where only a few trees are affected, it is best to seek out all such trees and treat them with an oil at the rate of 1 to 15. Inas- much as such an inspection may not discover all cases of infestation, it would seem advantageous to spray the balance of the trees with the same mixture diluted at 1 to 20. This dilution will reduce the possi- bility of the spread of the scale as well as the likelihood of any in- jury to buds or twigs from oil. — (Bui. 235, N. J. Exp. Sta. : Bui. 149, Md. Exp. Sta.; Cir. 88, B. of E. U. S. Dept. of Agr.) The Peach-Tree Borer.*- — In the form in which it is most famil- iar to the grower, the peach-tree borer is a white, grub-like cater- pillar with a yellowish or brownish shield-like head, which lives and feeds in the tree trunks at or just below the surface of the ground and makes irregular galleries or chambers just beneath the bark,, from which gum and sap ooze out to form conspicuous masses. These borers may be found at almost all periods during the summer, but are usually very small in late summer or fall and become an inch to an inch and a half in length in early summer. The parents of this borer belong to the Sesiid or clear-wing moths. The male is a shining, slender, steel blue, wasp-like crea- ture with two pairs of transparent wings marked with black and yel- low scales, and the abdomen is narrowly banded with yellow. It expands about an inch when the wings are fully spread. The fe- male is decidedly larger and stouter, deep blue except for a broad orange band around the middle of the abdomen, the hind wings only transparent. The larvae feed all summer and during the win- ter lie dormant doing no feeding but begin to do so with the rise of sap. Trees of all ages may be and are infested by borers, from the seedlings in the nursery to the venerable old relics still to be found in some gardens. In nursery trees and in small trees generally, a single larva may completely girdle and kill a tree. The work is usually done just below the surface of the ground. There is no in- secticide application thus far known that can be relied upon to kill borers once in the trees, * See page 885, Lesser Peach-Borer i . Male and Female Moths. 2. Cocoons Under Bark. 3. Trunk of a Ten- Year-Old Peach Tree Infested with Larvae. (Figures i and 2 Much Enlarged; 3. Much Re- duced.) Dept. of Agr. ENTOMOLOGY 55 An existing or already infested orchard should be carefully ex- amined at least twice in each year: as late as convenient in the fall, and again in the following end of May or early June. In the fall examination the earth should be removed from around the base of the trees to a depth of at least six and preferably eight inches, and every sign of a wound or place from which gum exudes should be investigated. There is needed a small, stiff, coarse brush to remove the gum and crush all surface feeding larvae ; a stout sharp knife to cut through the bark into cavities, and a more slender, longer blade to probe channels and burrows. Never cut more than necessary and never cut across the grain if it can be avoided. If a larva can be lo- cated, a straight slit through the bark into the cavity so as to hit the borer is all that is needed, and such a wound will heal almost at once. Between the end of May and the middle of June the process above described should be repeated. Leave the base of the trees exposed for a few days now, to toughen the outer bark and then, before again drawing up the soil, spray very thoroughly with a lime-sulphur, arsenate of lead mixture, to which an excess of lime has been added. Use one pound paste arsenate of lead to every five gallons of lime-sulphur, or one pound of dry arsenate to every ten gallons of lime-sulphur and apply with all the force possible to the exposed crown and for a distance of eighteen to twenty-four inches above the surface. Then cover and hill up at least six inches around the trunk after the application is thoroughly dry. The strength of the lime-sulphur wash may be that of the ordinary winter spray with double the required amount of lime. The object of this application is to hit young larvae that might later try to get into the trees. — (Bui. 235 N. J. Exp. Sta. ; Bui. 73, Georgia E. S.) The Lesser Peach Borer. — In the course of investigations of the peach borer by the Bureau of Entomology during 1905 another borer was found infasting the peach, inhabiting principally the trunk, especially of old trees or those showing injury from freezing or other causes. This insect, to be known as the lesser peach borer, has been found in western New York and adjacent portions of Canada, in Maryland and Virginia, and in Georgia, so that it would appear to be widely distributed. In the last-mentioned State it is very abundant and is the cause of important injury, infesting prin- cipally the trunks of the older trees, feeding on the soft bark, exca- vating burrows after the manner of the true peach borer. It has, however, been frequently taken at the crown of the root, and under these circumstances might readily be confused with the other species. This borer is the larva of a moth, both sexes of which are very sim- ilar to the male Peach-Tree Borer Moth. To control this species it Avill be advisable to closely examine the trunks as well as the crowns of the roots during the time of worming for the peach borer. The Peach Twig-Borer. — One of the most common enemies of the peach in the United States, is the twig-borer, or "bud worm" as it is sometimes called. Its occurrence has been reported from most of the peach growing states of the Union, both in the East and 56 INSECTS AFFECTING VEGETATION West. The twig-borer is principally an enemy of the peach, and usually we hear of it in connection with its damage to this fruit. It may be found, however, on all stone-fruit trees, but shows a de- cided preference for the peach. The larvae, hibernate in the little silk-lined chambers constructed within the bark and very close to its surface. In the spring of the year, about the time the peach trees bloom, the larvae leave their winter quarters and eat into the tips of the twigs, either beginning their work at the extremities or a short dis- tance below, sometimes hollowing them out for usually a distance of less than an inch from where the twig was entered, leaving a mere shell or hollow cylinder of the portion in which they have fed. Again they may merely gouge out the tip of a twig on one side, en- tering in as far as the pith and then leaving for some other twig. Thus they go from twig to twig, feeding first in one and then in an- other, until often the tips of a great many branches will be killed back, thereby checking their growth and more or less injuring the tree. The detection of their work is no difficult matter a short time after they begin feeding, for the leaves of affected twigs soon wTilt, and later dry up from the injury done to them. — (Year Book 1905, U. S. Dept. of Agr. ; Bui. 169, Col. Exp. Sta.) The twig-borer moth is a tiny, gray insect, about XA inch in length and having a wing expanse of about % inch. It is quite a beautiful little moth with its dark gray, fringed wings. It may be said that arsenate of lead, applied in the spring at the time the buds of the peach are beginning to open, will control the peach twig- borer as effectively and cheaply as the lime and sulphur wash, up to 50 gals, of water when the buds show pink at tips. — (Year Book this time the most universally used. Use at the rate of 5 lbs. to 1905; Col. E. S. B. 169.) The Brown Mite. — This mite passes the winter almost entirely in the egg stage. These eggs are tiny, red spherical-shaped, glassy objects, usually deposited in or near crotches of the branches. Hatch- ing takes place in the spring. At first the young mites are red in color and have only six eggs. Upon feeding for a short time moult- ing takes place, after which the mite is olive green, or brown in color, and has eight legs more or less tinged with red. It feeds principally upon the leaves, occasionally attacking the fruit, and may be detected by the faded out, pallid appearance of the foliage, dotted here and there with little black specks of excreta. Apple, peach, plum, cherry, pear, and almond trees were found infested. Apricot and quince do not seem to be troubled. Flowers of sulphur, one pound to three gal- lons of water, and enough soap so that the sulphur will mix with water, is a perfectly effective remedy when used as a summer spray. The Pied Spider. — This mite differs from the preceding one in its wintering habits; instead of living over in the egg stage, as the brown mite does, this species hibernates in the soil as an adult, close to trees upon which it has been feeding, or underneath rubbish of any kind. Eggs are laid in the spring by mites that have lived ENTOMOLOGY 57 through the winter. These eggs are pearly white, and may be seen as tiny specks on the under surface of the leaves. When first hatched from the egg this mite, like the species pre- viously treated, has only six legs, the fourth pair developing with the first moult. They are somewhat smaller than the brown mite, usually green in color while feeding upon the foliage of trees, with minute black dots on the dorsum of the abdomen. When feeding ceases in the fall, and they begin their downward migrations to the soil, they become an orange, or red color. Unlike the brown mite, the red spider has the power of spinning a web, and may easily be detected, when prevalent, by the presence of these webs on the foliage, or branches of infested trees. The appearance of injured peach foliage is not unlike the appearance of that injured by the brown mite, but is more inclined to turn yellow in patches. A sul- phur spray, the same as is recommended for the brown mite, is probably better than anything else that could be used during the summer months-.— (Bui. 169 Col. Exp. Sta. ; Bui. 152 Col. Exp. Sta.) California Peach-Tree Borer. — The most injurious insect in the Santa Clara Valley is generally conceded to be the California peach- tree borer. This insect is most abundant on peach and apricot trees, or on prune trees growing on peach and plum roots. It bores into the' bark just beneath the surface of the ground, and is most easily recognized by the very characteristic masses of gum that exude from the tree at the point of attack. These borers often become so abund- ant as to entirely girdle large trees, causing their death; and even when not so deadly their attack seriously cripples the tree. The labor necessary to dig out or otherwise destroy these insects amounts to a great deal. This insect is best known in its winter quarters, be- cause it is during the winter that practically all of the work for its repression is done. With the commencement of the flow of the sap in the spring, the older larva? proceed to the formation of their transformation tubes. These are sometimes, indeed quite commonly, formed within the bun'ows, especially if the amount of gum has not been excessive. In other cases they will be upon the surface of the bark at, or near, the mouth of the burrow. The most evident sign that the worm is working in the bark of the tree is the exudation of a greater or less mass of gum from the burrowT. Ordinarily, there seems to be a great deal of variation in the shape and direction of the burrow — about as many burrowing up as down. The general direction of the burrow is usually more nearly vertical than horizontal, though a few may go directly around the tree. The remedy, upon which the most dependence is placed in fighting the Eastern peach-tree borer, is that of digging out the worms. The time of the digging-out is almost always made a matter of convenience, and the facts we have so far learned in regard to the life history do not, as yet, prove that better results would follow a dif- ferent practice. An important feature of the digging-out method is that it is extremely difficult to find all, or even the larger worms, in a 58 INSECTS AFFECTING VEGETATION tree ; and if the worm.- are small their discovery is almost or quite im- possible. A single going-over of the trees is thus only partially effec- tive, and many orchardists have found that three times during the winter will not exhaust the supply, even though it is quite certain that no moths were flying during the intervals. The rush of other work usually prevents a summer digging-out of the worms, though it would seem that just as good or better results might follow from work at that season. — (Bui. 143, Cal. Exp. Sta.) The Peach and Plum Slug. — The adult sawflies are very active little insects. If one is observed on a leaf it will be seen to run back and forth across the leaf on the upper side, apparently peering over the edge, occasionally stopping for a moment at one of the nectaries at the base of the leaf and sipping the nectar. This sort of food seems to constitute their diet, as, in addition to visiting the peach- leaf nectaries, they were also observed visiting near-by cotton plants for nectar and honeydew, and one was seen on Japanese quince. The first damage by the larva consists in very small pinholes eaten into the leaf from the underside, all of the tissue being removed except the upper epidermis. As the larva grows and its jaws become stronger the size of the eaten patches increases until they become large blotches. The upper epidermis is, however, never eaten. So serious a menace is this insect to the peach and plum trees that, in a favorable season, the trees are completely defoliated in August. Lack of time prevented the writer from making any tests of remedies. Without doubt, however, an arsenical spray, such as arsenate of lead, would very effectively destroy these insects, and this poison is advised when the insects occur in sufficient numbers to war- rant treatment. The rapid increase in the spraying of peaches and plums with arsenate of lead in self-boiled lime-sulphur wash for the control of the plum curculio and fungous diseases of the fruit will unquestionably result in keeping the peach and plum slugs well re- duced in orchards. Its occurrence in injurious numbers is to be looked for largely in' small unsprayed home orchards, and the remedial measures indicated should be followed when its presence in undue numbers is noted. — (Bui. 97, Part V., B. of E. U. S. Dept. of Agr.) [See "Apple Insects."] PRUNE AND APRICOT INSECTS. The European Fruit Lecanium. — The insect heretofore gener- ally known as the brown apricot scale belongs to the subfamily of scale insects, the Lecaniinse, being naked but with hardened derm, and differs from the San Jose scale and European pear scale in that the horny covering of the full grown scale is a part of the body of the insect, while in the case of the other species mentioned the body is protected by a waxy covering made up from secretions and the molted skins of the larvae. The adult female of the European fruit Lecanium is about one-eighth to three-sixteenths of an inch long, three-thirty-seconds to one-eighth of an inch wide, and about one- eighth of an inch high, yellowish in color, marked with black. The older scales are shiny, oval, convex, and often covered with a mealy pruinose deposit ENTOMOLOGY 59 Distillate-oil emulsions at G per cent strength and crude-oil emulsion at 12 per cent strength, measured by their efficiency against scales and lichens, convenience of preparation and application and cost, are the sprays best adapted for the European fruit Leca- nium. All sprays, to insure the best results, should be applied with a power outfit at a high pressure (180 to 200 lbs.) . A coarse, drench- ing spray applied with a crook nozzle is preferable, and February is the best month in which to spray.— (Bui. 80, Part VIII., B E U S. Dept. of Agr.) INSECTS AFFECTING THE PLUM. The Plum Curculio. — The small, crescent-shaped punctures so commonly found on plums and other stone fruits in orchards east of the Rocky Mountains are made by a small snout-beetle of rough sculpture, known as the plum curculio. These bettles issue from their winter quarters about the time the trees are in bloom, and feed on the tender foliage, buds, and blossoms. Later they attack the newly set fruit, cutting small circular holes through the skin in feeding, while the females, in the operation of egg laying, make the crescentic cuts so characteristic of this species. The egg, deposited under the skin of the fruit, soon hatches into a very small whitish larva or grub, which makes its way into the flesh of the fruit. Here it feeds greed- ily and grows rapidly, becoming, in the course of a fortnight, the fat, dirty white worm so well known among fruit growers. To be reasonably effective in killing the beetles, arsenate of lead should be used at the rate of 2 pounds to 50 gallons of water. Paris green or green arsenoid should not, on stone fruits, be used stronger than 1 pound to 150 or 200 gallons of water.— (Cir. 73, U S Dep of Ag., B. of E. ; Bui. 25 Indiana Agr. Exp. Sta.) The Peach Tree Borer: See pages 54, 55, and 57. The Plum Slug (The Pear Slug): See pages 47 and 58. The San Jose Scale : See page 32. The Plum Gouger.— The gouger is a small snout-beetle, about a quarter of an inch long. Its method of work is much like that of the curculio. It is mottled brown in color, with short whitish hairs that give it a pruinose appearance. It can be easily distinguished from the curculio by its size and by the absence of humps on the wing-covers. It confines its work for the most part to the Mississippi valley and the West. l The adult beetle hibernates in the winter, and in the spring at- tacks the flowers of the plum in a manner at once peculiar and in- genious. The part eaten is the ovule or the part which would if uninjured, in time become a fruit. The gouger eats a hole in the side of the calyx, the green cup at the base of the flower, and reach- ing in with its long beak eats the coveted part. Later the gouger eats holes in the young fruit, sometimes laying eggs therein. The egg is laid in a hole in the fruit with no crescentic flap as in the ease of the curculio. The young grub works directly into the soft pit, and lives there, leaving no indication of its presence, except per- 60 INSECTS AFFECTING VEGETATION haps a scar on the outside of the fruit and the gum which exudes from it. Sometimes, however, a malformation of the fruit results. Here in the pit, the pupal stage is passed, and during the latter part of August, the adult beetle emerges. The fruit usually does not fall until just previous to the exit of the inhabitant. During the period of bloom and just before and after this pe- riod, the beetles may be obtained by jarring, just as is done for the circulio. Jarring should be kept up just as long as the beetles are obtained, for one little beetle obtained early in the season amounts to a good deal. It must be borne in mind that the gouger does not thin the fruit as does the curculio, but that the gouged fruit re- mains until late, drawing on the strength of the tree about as much as a perfect plum. As most of the fruit falls before the beetles make their exit, im- mediate destruction of fallen fruit will make away with many beetles. Hogs accomplish this very nicely but if hogs are objectionable, pick up the fruit by hand and bury it just as soon as it falls. The arsenites do not seem to prove as beneficial as we could wish, but no doubt they will pay for the application. Prof. C. P. Gillett of Colo- rado, recommends the hand picking of all gouged fruit. This com- bines the benefits obtained by thinning, with those resulting from the death of the insect. — (Bui. 24, Mich. Agr. Exp. Sta.)_ The Plum Leaf-Miner. — The plum leaf-miner in its injurious stage is a smooth, greenish white larva, one-sixth inch or less in length, found during late June and early July feeding between the outer layers of the leaf. Hatching from an egg attached to the under surface of the leaf, the larva penetrates the tissue and first eats a narrow linear mine an inch or less in length, then widens the mine so as to produce an irregular, more or less ovate blotch about one- half inch long. The part of the leaf so injured turns brownish and dies. From three to twelve mines are often found in a single leaf. The trees become partially defoliated and the fruit may fall pre- maturely. When continued for a series of years this injury tends to weaken the vitality of the tree and to injure the size and quality of the crop. The adult of the plum leaf-miner is a small bronzy black moth having an expanse of one-seventh to one-fifth inch. The forewings are crossed by a shining white band on the outer third, and the head bears a conspicuous orange tuft. These moths emerge from cocoons at or near the surface of the ground during the daytime in the lat- ter part of May and in early June. During the day they remain quietly on the bark of the trunk and larger branches, none being found on the leaves. Several hundred moths are often found on a single tree ; when disturbed they suddenly take flight and most of them settle on the opposite side of the tree. They gradually de- crease in numbers, and about the middle of June they disappear. God furnishes the ideal winter quarters for the cocoon. The plum leaf-miner has proved to be a difficult insect to control, owing to the fact that from the time the larva leaves the egg it feeds en- tirely within the leaf out of reach of any poison spray. Measures ENTOMOLOGY 61 directed against the moths, eggs and larvae have all proved fail- ures, and only partial success has been attained by thorough cultiva- tion to destroy the larvae and pupae in their cocoons. However, thorough cultivation seems to be the only remedy at hand at present. Plum Aphids. — Several species of plant lice infest the plum, the two most important being the true plum-louse which remains on the plum all the year round ; and the hop-louse. This latter spe- cies is restricted to regions where hops are grown, as a matter of" course, and migrates, back and forth between the two host plants, spending the summer and early fall on hops, and late fall, winter and spring on cultivated or wild plum. In other words the eggs are laid on the plum branches in October to hatch out the following spring. The young lice which are at this stage provided with wings, migrate to the hop yards for the summer, their progency coming back to winter quarters in the fall. The true plum-louse remains the year round on the plum trees, curling the leaves and sometimes doing considerable damage. The ordinary spray of kerosene-emul- sion, or tobacco-water, will kill the lice easily enough if they can be reached. Very thorough work in the central part of the tree is re- quired to hit them because of the curled condition of the leaves. — (Bui. 308, Cornell Exp. Sta.; Bui. 24, Mich. Exp. Sta.) INSECTS AFFECTING THE CHERRY. The Divaricate Buprestis. — This is a medium sized beetle with very hard, strong wing-covers and a flattened body. The surface is bronzy, and furrowed, the spaces between furrows being highly pol- ished. This insect bores into living wood much as does the flat- headed apple-tree borer. It works in cherry and most of our stone fruits beside a number of forest trees. The remedies are the same as those for the flat-headed borer of the apple. The Cherry-Tree Plant-Lovse. — A large, black, polished plant- louse that works on the young shoots and tender foliage of the cherry, often appearing in very great numbers. They multiply rapidly, sometimes covering the twigs and young fruit, and secreting a sticky sweetish liquid called honey-dew. This attracts ants, yellow-jack- ets, flies, etc. Late in the season they often become numerous be- fore laying the eggs for the spring brood. Kerosene-emulsion or any of the contact insecticides, applied in the ordinary way, except that it should be a little stronger than when used for green lice. It must be borne in mind that each louse must be hit in order to be killed. The "Cherry Leaf-Beetle. — A small, dark-red beetle less than one-fourth of an inch in length, oval in form, and with the antennae and parts of the legs black. The small beetle feeds on cherry. The writer has seen them in great numbers on pin cherry (a wild cherry) at AuTrain Falls in late August. The beetles have welcomed with enthusiasm the introduction of the cultivated cherry in their haunts, readily accommodating their taste to the new food. They feed on the leaves, and often come in large numbers, appearing in June and again in September. In the Northern Peninsula they do a great deal of damage to young trees, coming out of the ground from a depth of 62 INSECTS AFFECTING VEGETATION several inches, and attacking the young foliage about the first of June. The larva? also works on the foliage, following the adults. When on old trees not in bloom, these beetles may be killed with paris-green and lime, one pound of the poison to one hundred and seventy-five gallons of water, but on very young trees the case is more difficult. Mr. Geismar, the superintendent of the Upper Peninsula Experiment Station, points out the fact that the beetles either hibernate or pupate under the surface of the soil, often at a depth of several inches, and usually within a few inches of the base of the tree. He finds also that they are almost sure to climb the tree instead of flying, being somewhat sluggish on first coming to the surface. This suggests the use of narrow bands of sticky fly-paper or loose cotton at such times in the case of young trees. The beetles eat very voraciously and a few dozen can work havoc in a young tree, especially if it is in bloom and one does not wish to spray. [Bud Moth, see page 43; Cherry Slug or Pear Slug, see pages 47 and 5S; Apple-Tree Tent-Caterpillar, see page 39; White-Marked Tussock-Moth, see page 41; Canker- Worms, see page 38; Fall Web- Worm, see page 39.] INSECTS AFFECTING THE BARK. [Fruit Bark-Beetle, see page 32; San Jose Scale, see page 32.] The Cherry Fruit-Fly. — The work of this cherry maggot causes large losses. The maggots feed upon the juicy flesh of the ripening cherry, usually near the pit. They form an irregular, rotten-appear- ing cavity which is represented by the black cavity near the pit. Until the maggots get nearly full-grown their work does not show on the surface of the fruit. Soon after picking-time, however, the rotting extends to the skin which sinks in. Usually but a single maggot is found in a cherry; we have sometimes found a second, but always much smaller, maggot in the same fruit. The maggots do not tunnel all through the flesh of the cherry as does the apple maggot in apples. The insect doubtless spends the winter in the soil, usually not more than an inch below the surface. During the spring months, the transformation from a pupa to the adult insect takes place. Doubtless the pest will spread quite slowly from tree to tree and thus from orchard to orchard, as the adult insects are slow in their movements and are not long-fliers. This is a very important fact for it makes the checking of this new cherry pest largely an individual matter, to be worked out independently by each cherry-grower. Doubtless the sweetened arsenical sprays now employed against the apple maggot adults will be found effective in this case. The insects of the peach and plum are nearly identical. — (Bui. 172, Cornell Agr. Exp. St a.) GRAPE INSECTS. The Grape Root-Worm. — As the name indicates this worm in- fests the roots of the grape, devouring more or less completely the ENTOMOLOGY 63 smaller roots and rootlets and eating pits or burrows into the outer portion of the larger roots. It is the larva of a small, hairy, chest- nut-brown beetle which makes its appearance in vineyards at about the close of the blooming period of such varieties of grapes as Con- cord, Niagara, Catawba, and Delaware. The beetles feed freely on the upper surface of the leaf, eating a series of patches or holes through to the lower surface, thus producing characteristic chain/ like feeding marks, by which their presence in vineyards may be readily detected. The injury to the foliage, however, it quite unim- portant compared to the work of the larvse on the roots. When the larvse are abundant the vines may be killed in the course of a season or two, but usually the plants will live longer, though making but a feeble growth and failing to produce profitable crops. The death of vines or the gradual failure of a vineyard should call for an examination of the foliage for the feeding marks of the beetles and of the roots for the work of the larvse on these parts. The grape root-worm, or grapevine Fidia, is without doubt a native species, feeding originally on wild grapes, as it does at the present time. In addition to cultivated varieties of grapes it has also been recorded as feeding on the Virginia creeper and the Amer- ican red-bud. The beetle, or parent insect of the grape root-worm is about one-fourth of an inch long, rather stout, with long legs, the body brownish in color and covered with grayish white hairs. The adults make their appearance in vineyards beginning about the close of the blooming period of the vines, which in the New York, Pennsyl- vania, and Ohio grape districts, during normal seasons, will be from about the 15th to about the 20th of June. The great majority of beetles will appear during the latter part of June and the first two or three weeks of July, though a few will be coming out during the latter part of July, and stragglers may appear for a month or six weeks later. In a given locality there will be some variation in the time of appearance, which will be earlier on light, sandy soils or warmer locations and later on heavier soils. In the course of a few days after emergence the beetles begin to feed, eating rows of holes in the upper surface of the leaf. Eggs are deposited in patches usually from 25 to 40. On hatching, the larvse drop to the ground. At this time they are about one-seventeenth of an inch in length, and from their small size are readily able to find their way through the soil. Al- though the powers of locomotion and endurance of the young larvse are considerable, to enable them to overcome difficulties in reach- ing their food, many doubtless fail to do so and perish. When estab- lished on the roots, however, the grubs feed freely and grow rapidly. By fall the majority of them will be full-grown or nearly so. Upon the approach of cold weather they descend into the earth several inches, a few as much as a foot below the surface, and here construct oval earthen cells in which they pass the winter. With the approach of warm weather the larvse ascend to a point near the surface, the immature ones completing their growth, and the pupal stage is en- 64 INSECTS AFFECTING VEGETATION tered mostly from about 2 to 3 inches below the surface of the soil and within a radius of 1% to 2 feet from the base of the vine. The full-grown larva is about five-eighths of an inch long, the body whit- ish, resting in a curved position. The head is yellowish brown in color, with a transverse diameter somewhat less than that of the body. The full-grown larva prepares an earthen cell, within which it shortly changes to the pupa or turtle stage. In this condition the insect is soft and helpless, and the earthen cells are readily broken open and the pupae crushed or otherwise killed by stirring the soil. As stated, the majority of the larvae pupate about 2 or 3 inches below the surface of the ground, and this makes possible their destruction in large numbers by timely cultivations, as will be explained under the discussion of remedies. The insect may be fought in three important ways, namely, by poisoning the adults with an arsenical spray, jarring them from the vines onto sheets, and destroying the pupae in the soil by cultivation. Shortly after emergence the beetles begin to feed upon the foliage, eating holes in the upper surface of the grape leaves, and hence may be readily poisoned. To be effective, however, the poi- soned spray must be applied at the right times and with great thor- oughness. The beetles begin to put in an appearance at about the close of the blooming period. Careful watch should be kept, and upon the first signs of the chain-like feeding marks on the leaves the vines should be thoroughly sprayed with a poison. A second ap- plication should be made in a week or ten days. These applications are intended to poison the newly emerged beetles during their first feeding and before they have deposited their eggs to any extent. If applications be delayed two or three weeks beyond the time indi- cated, a considerable percentage of the eggs will have been deposited, and the treatments will lose much of their value. Vineyardists hav- ing this pest to contend with should not make the mistake of spray- ing a little too late, but should have everything in readiness to begin applications upon the first appearance of the beetles. The beetles plainly avoid feeding on foliage sprayed with Bordeaux mixture or arsenate of lead, seeking the unsprayed leaves as much as possible. It is therefore especially necessary to make applications with great thoroughness, poisoning as nearly as possible the upper surface of every leaf, so that the beetles will be poisoned or forced to leave the vines for food. This desired thoroughness of treatment is not ob- tained as a rule by vineyardists, and greater care should be exercised in this work. In commercial vineyards the tendency will be to hurry through the work, covering 12 or 15 acres per day, using an insufficient amount of spray. AVith the spraying machinery in com- imon use 7 to 8 acres per day is about all that may be covered with the desired thoroughness and about 125 gallons of spray mixture should be applied per acre. In spraying for the grape root-worm, the poison, 3 lbs. of arsenate of lead should always be applied in Bordeaux mixture, ENTOMOLOGY 65 Doctor Felt has made extensive practical tests of jarring the beetles from the vines and catching them on sheets or special forms of catchers run under the plants or along the rows, and considers this to be an effective plan of controlling the pest, the jarring of the vines causing many of the beetles to fall in their efforts to escape de- tection. A sheet of canvas placed on the ground beneath the vines will serve to catch the beetles, but where work of this kind is done on a large scale special apparatus must be provided. There is room for considerable ingenuity in constructing catchers that will suit in- dividual conditions. Concerning the value of jarring, Doctor Felt said— Our experience with collectors has demonstrated the prac- ticability of catching the beetles, and we recommend this operation for all badly infested sections, and that the collecting be begun as soon as the beetles appear on the vines in any numbers, say where there are 12 or 15 on one. The operation should then be repeated at intervals of 5 to 7 days till the vines have been gone over two, three or four times, depending somewhat on the number of insects which are captured. It will be found that it is much easier to catch the beetles on warm days, when it should be done, than in cool weather. While the grape root-worm may be present in well cultivated vineyards, it is much less destructive than in vineyards which receive indifferent cultivation or total neglect. It has long been known that much good may be done in controlling insects which live under- ground by breaking open their pupal cells and crushing or otherwise killing the helpless pupae. After the larvae have become full grown the great majority pupate but 2 or 3 inches below the surface of the soil, and mostly within a radius of iy2 or 2 feet from the base of the vine. In this stage the insects are quite helpless, and are killed in large numbers by a thorough breaking up of the soil around the base of the plants. The details of this work are very important and re- quire explanation. With the last cultivation in the fall the earth should be thrown to the vines on each side, forming a ridge along the row. The fol- lowing spring the larvae in making their way toward the surface of the soil to pupate will mostly work up in this ridge of earth, above the surface of the roots, and there enter the pupal stage. The culti- vation of the vineyard in the spring should be so adjusted that this ridge of earth may be thrown away from the vines when most of the insects are in the pupal stage, as one of the regular cultivations. An implement known as a "horse-hoe," generally used in vineyards, may be employed to great advantage in this work ; but as it is not practicable to remove the earth from immediately around the vine owing to danger of injury, it is necessary to follow the horse-hoe at once and remove the earth with a hand-hoe. The latter work is also done as a part of the regular vineyard treatment to keep down weeds and grass and is timed so as to supplement the plowing with the horse-hoe for the insect. Following the removal of the ridge of earth from along the vines, it is well to keep the ground stirred at fre- 66 IXSECTS AFFECTING VEGETATION quent intervals by means of a cultivator to further insure the destruc- tion of the pupae. Grape Berry Moth. — The larva of the grape berry moth in- fests the berry or fruit of the grape. The first generation attacks and webs together the grape clusters even before the blossoms open or soon after the grapes are set. Later-appearing larvae bore into the green or ripening fruit and produce a purplish spot much re- sembling in appearance the injury due to the black-rot fungus, with which it is frequently confused. Within the fruit the larvae feed on the pulp and seeds, passing from one grape to another, and several of these discolored and shriveling berries will often be found more or less webbed together with numerous particles of larval excrement, and sticky with exuding grape juice. The American grape berry moth occurs from Canada south to the Gulf and westward to California. In some vineyards a loss of from 25 to 50 per cent of the crop is not infrequent, and in occasional in- stances the destruction of the fruit is practically complete. The grape berry moth is small, the wings expanding not quite one-half inch. The general color is purplish brown, the wings with) markings. Moths appear in the spring from hibernating pupae, beginning about the time the shoots of the grape are push- ing out, and continuing to emerge for some weeks. The earlier- appearing individuals deposit their eggs on the blossom clusters, while those coming out after the blossoms are shed oviposit on the clusters of young grapes. About 3 weeks are required for a larva to complete its growth in summer, when it is about three-eighths of an inch in length, slender, light greenish to purplish in color, the head slightly bi- lobed, greenish above, and brownish in front, the thoracic feet blackish. When ready to pupate the larvae go to the leaves, and a small portion is cut loose, except along one side, and bent over and fastened down with silk. Beneath this a thin, whitish, silken cocoon is spun, and in 3 to 4 days the larva changes to a light greenish brown pupa, from which the moth will emerge in some 12 to 14 days. Second-brood larvae infest the grape during July and August, the later-appearing individuals probably not devel- oping to moths but hibernating in the pupal condition. Many of the earlier-appearing insects of this brood appear to complete their life cycle, and moths develop, giving rise to a third generation of larvae. The use of arsenical poisons against the first brood of the grape berry moth was recommended by Mr. Marlatt, of the Bureau of Entomology, in 1895. Since this time the recommendation has been amply justified in the experience of numerous vineyardists, who, in connection with the fight against the grape root-worm, found that their early sprayings for this pest were also controlling the grape berry moth. Professor Slingerland reports an instance in which three timely applications of arsenate of lead, at the rate of 10 or 12 pounds to 100 gallons of water, gave almost absolute protection during the rest of the season. ENTOMOLOGY 67 As would appear from the life history of the insect, most effec- tive work may be done by destroying the first brood larvae, which feed in the clusters of blossoms and berries. The first treatment should be made just before the blossoms are ready to open, and the second just after the blossoms have fallen. A third treatment in a week or ten days is also advisable in badly infested vineyards. In all these treatments special care should be exercised to force the spray well through the clusters of blossoms and young fruit. It will be noted that the second and third treatments for the grape berry moth will coincide with the first and second treatments for the grape root- worm, and the arsenicals recommended for that insect will be equally satisfactory for the grape berry moth. This practice is often followed by vineyardists, and is especially directed against larvae of the second brood. The infested spotted green berries, which are readily seen, should be carefully searched for and destroyed. This practice will lessen injury from a possible later brood, and if carefully followed would reduce the insects materially in the vineyard from year to year. Inclosing each cluster of grapes in a paper bag soon after the blossoms have fallen should protect them from injury from second and third-brood larvae, and Avould also afford protection from the rose-chafer and from black-rot. This practice is especially useful in the small home vineyard. The fact that the insect passes the winter in fallen leaves has led to the recommendation that these be raked up and burned. From Mr. Johnson's observations it would appear important to collect these early in the fall, as the pupae are to be found mostly on the 10 or 15 per cent of leaves which fall first, and great care must be taken to col- lect those leaves more or less imbedded in the soil. After remaining on the ground for a while, probably many of the cocoons break off from the leaves and would thus not be collected with the leaves. It is probable also that many of the insects could be destroyed by covering the leaves with soil early in the fall. Grape Curculio. — The grape curculio is one of the snout beetles belonging in the same family as the so-called plum curculio. The parent beetle deposits her eggs in little cavities which she eats into the grapes, and the resulting larvae feed upon the pulp and seeds, producing an injury quite similar to that done by the grape berry moth. The beetles cut small, rather characteristic holes in the grape leaves when feeding, and the berries often show a purplish col- oration at the point punctured in egg-laying. If infested berries be examined it will be readily possible to distinguish between the grape curculio and the grape berry moth, since the grubs of the former are ■whitish and quite destitute of legs, whereas the larvae of the berry moth have well-developed legs, are greenish in color, quite agile, and likely to escape quickly upon being disturbed. The grape curculio is a native species, feeding originally on the wild grape, as it does at the present time. Mr. Brooks has shown that the insect is readily controlled with arsenical poisons and, as will be 68 INSECTS AFFECTING VEGETATION detailed later, treatments for the root-worm and berry moth will also keep this pest under control. The insect passes the winter in the adult or beetle stage, hiding under trash in and near vineyards, especially bordering woods. About the time in the spring that the grape is in bloom the beetles come from their hibernation quarters and for the first few days or a week are quite sluggish, but gradually become more active, feeding on the foliage of the grape until the berries are about one-fourth grown or of sufficient size to be suitable for receiving the eggs — ac cording to Mr. Brooks, in 1905, covering a period of about 25 days. This habit of feeding on the exposed portions of the vines some 3 to 4 weeks before egg-laying permits of their ready destruction by ar- senical poisons. Late in June, in the latitude of West Virginia, the females begin depositing eggs in the berries, excavating a cavity in which a single egg is placed. About 4 to 6 days, varying with the temperature, are required for the eggs to hatch, and the resulting larva burrows through the pulp, reaching the seed in 3 or 4 days, which is penetrated and the contents devoured. In 12 to 15 days the larva has become full grown and leaves the berry by eating a hole to the outside, falls to the ground and at once seeks a suitable place for pupation, as under stones, lumps of earth, or just below the sur- face of the soil. Here an earthen cell is made and the larva trans- forms to the pupa, the adult beetle emerging in the course of 18 or 19 days, at first blackish in color with gray hairs, but soon becoming the normal brown color. The beetles feed freely upon the foliage of the grape in the spring for several weeks before egg-laying begins and continue feed- ing in the fall after egg-laying ceases along with beetles of the new generation, and it is thus an easy matter to bring about their de- struction by arsenical sprays. The treatments advised for the grape berry moth and root-worm, with perhaps an additional treatment 2 or 3 weeks later, will practically control the insect. Fruit may also be well protected by bagging the clusters soon after the grapes have set, as already mentioned in connection with the grape berry moth. Grape Leaf-Hopper. — Throughout the United States and Can- ada, wherever the grape is grown, this small leaf-hopper will almost invariably be found in greater or less numbers infesting the lower surface of the leaf, where it feeds and breeds, increasing in numbers as the season progresses, until by late summer and fall the vines are often literally swarming with it. Throughout its extended range the insect may be quite destructive in some localities nearly every year, and is likely to become so elsewhere at any time. The grape leaf- hopper is an insidious pest, often not noticed by the vineyardist until late summer and fall, when the yellow and brown-blotched leaves, falling prematurely, attract attention, by which time the injury has been done. The insects in feeding extract large quantities of liquid food, sucking it out from the interior of the leaf by means of their tube-like mouth-parts. When they are abundant this constitutes a heavy drain on the vitality of the plant. The injury to and loss of Three- Year-Old Peach Tree Injured by San Jose Scale. Dept. of Agr. (See page 32.) Apple Tree Badly Infested with S vn Jose Scale. Many Branches Killed. Dept. of Agr. ISee page 32.) ENTOMOLOGY 71 leaves prevents tne proper assimilation of food by the Vines; the fruit may be materially reduced in quantity and will lack much in flavor and sugar content. Although the yearly loss to grape growers from the attack of this species is sufficient to place it among the first-class pests of the vine, but little effort ordinarily is made to control it, per- haps principally because no very practicable remedy has until re- cently been proposed. The adult grape leaf -hopper is quite small, measuring not more than one-eighth of an inch in length. It is very agile, moving with almost equal facility in all directions, and flies out from the vines often in swarms upon slight disturbance. The insect passes the win- ter in the adult condition in hibernation in trash in and near vine- yards, in the edges of neighboring woods, in grass along gullies, in ditches, etc. Early in the spring the insects come from winter quar- ters and attack almost any succulent vegetation at hand. By the time the foliage of the grape appears they are out in large numbers and begin to infest the vineyards. These adult hoppers of the hiber- nating generation feed and breed on the lower or earlier-appearing leaves, gradually disappearing as the season progresses, but not before some of their progeny have reached the adult condition. Some weeks are spent by the adults in the spring in feeding before egg-laying begins. Eggs are placed just beneath the epidermis in the lower leaf surface, usually singly but also in groups of from 6 to 9, the egg stage, according to Professor Slingerland, lasting from 9 to 14 days. Egg-laying probably continues for two months or more. When just hatched the young hopper is very small, whitish in color, with red eyes, later becoming striped with yellow. In the course of their growth these nymphs molt four times the white skins being very nu- merous on the lower surfaces of badly infested leaves. The nymphs feed in the same manner as the parents, sucking juices from the leaves, at first on the lower surface of the older leaves where they were born, but later spreading more or less generally over the plant. They are very agile, running in all directions, but do not leap or hop. The grape leaf-hopper has proved to be a difficult pest to com- bat successfully. Various practices have been proposed, such as the use of trap lanterns to burn at night, the raking and burning during winter of fallen leaves and trash in vineyards, the use of sticky shields or fans to catch the adults as they fly from the vine on being dis- turbed, and in California the use of insect nets for the same purpose. Extensive field experiments were made by Professor Slingerland. He found that large numbers of the hibernated adults could be caught on sticky shields carried along each side of the row, the in- sects being frightened out by disturbing the vines. This work is done early in the season, before oviposition takes place to any extent. A light wooden frame is made, 7 or 8 feet long by 4 feet high. To the crosspiece at the bottom, which should be up from the ground about a foot, are fastened several stiff wires of the shape of a hayrake tooth. These are fastened so that the points curve inward and downward to the ground at base of plants when the shield is held in place beside the vines. The whole framework, including the wires, is covered 72 INSECTS AFFECTING VEGETATION with oilcloth which is coated with a sticky substance, made by using melted resin, 1 quart, and castor oil, 1 pint. Early in the season the insects will be found mostty on the lower leaves and the frame need not be high. As the higher leaves are invaded the height of the frame must be increased. In controlling the insects in this way it is very important to catch the over-winter- ing adults before egg laying has begun, thus greatly reducing the number of progeny to appear later, and the operation of catching the insects must be repeated at frequent intervals. Extensive tests with sprays were also made, and it was found practicable to destroy the young wingless hoppers or nymphs with a whale-oil soap solution, the soap being used at the rate of 1 pound to 10 gallons of water. The spraying must be done very thoroughly, covering the under surface of the leaves, as only those nymphs are killed which are actually hit with the spray. This work should be begun when it is observed that the young are becoming common. It is likely that an 8 to 10 per cent kerosene emulsion could be used, which would obviate this difficulty, and would prove equally effective in killing the young hoppers. Thorough cleaning up of fallen leaves and trash in vineyards during the winter will undoubtedly destroy many hibernating adults, and if this work be extended to adjacent areas where the insects are likely to find shelter, the reduction in their numbers will be mate- rially greater. Where practicable the burning over of adjacent meadows, wood lots, and spaces along fences is very advisable. It has been observed that in vineyards in which clean culture is practiced, all grass and weeds being kept down throughout the season, the hop- pers are notably less abundant than where this practice is not fol- lowed. The absence of suitable hibernation quarters in the vineyard causes them, largely, to migrate elsewhere, and vineyards receiving such care are much less seriously infested the following spring and summer. The grape leaf-hopper secures its food by sucking juices from the interior of the leaf, and arsenical poisons useful against the grape root-worm and the grape berry moth are quite useless against this pest. Grape Leaf -Folder. — Observing grape growers have often no- ticed, especially during midsummer and later, grape leaves folded to- gether, the interior (upper) surface of the leaf being more or less skeletonized, and within the fold a slender larva, which, upon being disturbed, is apt to wriggle out and fall or hang suspended by a thread. This insect, the grape leaf-folder, is widely distributed and a few are to be found in vineyards almost every year, while here and there throughout their range they may be so abundant as to do seri- ous injury. There are two broods each year in the more northern States and three or possibly more in the South. The insect winters in the pupal stage in the folded and fallen leaves, the moths appear- ing in the spring shortly after the foliage puts out, and the eggs^ are placed in small patches here and there on the vine. Upon hatching, the young larvee attack the foliage, folding the leaves as stated, Mr» ENTOMOLOGY 73 Johnson has observed that larvae of the first brood may attack bunches of grape blossoms and young fruit in a way similar to the grape berry moth. In 3 or 4 weeks the larvae are full grown and trans- form to pupa within the folded leaves, moths emerging some 8 or 10 days later. By midsummer and fall the insects may become quite abundant, and in badly infested vineyards the folded leaves are everywhere in evidence and are quite conspicuous from the color of the lower surface. In the fall the larvae pupate in the folded leaves and pass the winter in these on the ground. Where the insects are but moderately abundant it will be quite practicable to search out the folded leaves and crush between the hands the larvae or pupae within. The destruction of the first brood in this way would greatly reduce the number of the insects later in the season. Vines sprayed with arsenicals for the root-worm and the berry moth will be well protected from the leaf-folder, for in this way the majority of the leaves will be sufficiently poisoned to insure the de- struction of the larvae and prevent the folding of the leaves. After a leaf has been folded the larva is practically safe from poisoning. As the winter is spent in the pupal stage in the leaves on the ground many of the insects may be destroyed by collecting and burning the fallen leaves, as recommended in the case of the grape berry moth and the leaf-hopper. Grapevine Flea-Beetle. — Early in spring, as the buds of the grape begin to swell and burst, these may be scooped out or entirely consumed by a small blue or greenish beetle, measuring about one- fifth of an inch in length, of robust shape, with thick thighs, and jumping readily from the vines upon being disturbed. "When the beetles are abundant all of the buds on the vines may be quite de- stroyed, greatly retarding leafing out or even causing the death of the plant. Later the young foliage is eaten by the beetles, the fe- males depositing their eggs more or less on the leaves, but largely, according to Slingerland, in cracks in the bark at the base of buds, between bud scales, or even in the holes which have been eaten into the buds. The resulting larvae feed on the leaves of the grape, mostly on the upper surface, and are thus readily destroyed with sprays. In 3 or 4 weeks the grubs have attained full growth ; then, dropping to the ground, they make an earthen cell an inch or so below the sur- face, and transform to pupae, from which the adult beetles will emerge in the course of 1 or 2 weeks. The new brood of beetles feed upon the-grape and other plants, going into hibernation in the fall and appearing the next spring to attack the buds of the grape, as stated. In the Northern States Slingerland's studies have shown but one generation of the insect each year. In the South two or more generations annually are supposed to occur, but definite evidence on this point is wanting. The flea-beetle is native to North America, and occurs very gen- erally throughout the eastern half of the United States, its western limits being Minnesota, eastern Nebraska, Kansas, and Texas. Its natural food is undoubtedly the wild grape, though numerous other 74 INSECTS AFFECTING VEGETATION plants are fed upon, as plum, apple, pear, quince, blue or water beech, elm, etc. In vineyards which are regularly sprayed with arsenicals and Bordeaux mixture the flea-beetle will be effectively kept in check. The first application for the berry moth before the blossoms open, together with the application made after the blossoms fall, will destroy the larvae, since these feed almost exclusively on the upper surface of the leaves. The insects thrive best in neglected vineyards, and may become quite abundant and destructive locally. Where it is desired to treat for this insect only, the vines should be thoroughly sprayed with an arsenical just as the buds are beginning to swell, or somewhat earlier. A close lookout must be kept for the first signs of the beetles, and the poison must be applied immediately. The delay of a day or so may mean the loss of the buds, and hence of the fruit crop. In the small home vineyard it will be practicable to search out the beetles and remove them by hand, doing the work in the morning when they are less agile. As stated, the destruction of the larvae when feeding on the foliage later will be very easily accom- plished by spraying with arsenicals. It will also be quite practicable, as stated by Doctor Howard, to jar the beetles from the vines on canvas frames placed beneath, which should be kept saturated with kerosene. Rose-Chafer. — About the time of blossoming of the grape in the spring the rose-chafer may suddenly put in an appearance, often in enormous numbers, the long, spiny-legged, awkward, brownish beetles literally covering the plants, feeding at first upon the blos- soms, but later attacking the young fruit and foliage, the leaves being eaten bare, except the larger veins. This insect is a very gen- eral feeder; it attacks practically all fruits — e. g., apples, plums, cherries, peaches, etc. — as well as various vegetables, grains, and grasses. Many ornamental plants, such as Spiraea, Deutzia, and roses, are attacked, and its injuries to the last-mentioned have led to^ the use of the common name of rose-chafer or rose-bug, though it is perhaps now most commonly complained of from its injuries to grapes and other fruits. When abundant, the beetles may do serious injury in vineyards, quite destroying the blossom clusters or the newly set fruit. Berries not actually devoured are often so marked by the beetles that they become misshapen and crack as they grow, the seeds often protruding. After 3 or 4 weeks of feeding the beetles may disappear almost as suddenly as they came. The insect lives in the larval stage underground, feeding on the roots of various plants, especially on the roots of grasses. In general, it breeds principally in light sandy soils, especially in meadow lands, but also in other places where there is more or less of growth of grass and weeds, and, to a less extent, in cultivated ground. Wet, clayey, or compact soils do not furnish desired conditions for the insects, and from the fact that they are largely confined to the lighter soils it becomes practicable to reduce them greatly^ by planting these to annual crops which receive thorough cultivation. EXTOMOLOGY 75 The beetles deposit their eggs singly, burrowing beneath the soil, laying, according to Doctor Smith, from 12 to 20 eggs. The result- ing larvae feed upon the roots of various grasses and possibly weeds and other vegetation. They are mostly full grown by fall, and bur- row below the frost line, where the winter is spent. With the coming of spring the grubs ascend toward the surface and enter the pupa stage, from which in from 10 to 30 days, varying with the tempera- ture, the beetles develop and attack the grape and other plants, as stated. There is thus but one generation each year, the principal injury of the insect being done during the 3 or 4 weeks of its life as a beetle. The rose-chafer is an exceedingly difficult insect to combat suc- cessfully. When the insect occurs only in moderate numbers, arseni- cals will be reasonably satisfactory; but when it occurs in swarms, the plants are reinfested as fast as the insects are killed. A heavy application of arsenate of lead, say 5 to 6 pounds to 50 gallons of water or Bordeaux mixture, with IV2 pints of molasses added, will largely protect the vines. Very thorough applications should be made upon first signs of the insects and repeated as necessary. The numbers of this insect may be considerably lessened by restricting its breeding grounds. In vineyards on sandy or light soil especial care should be taken to keep the rows and surroundings free from weeds and grass, upon the roots of which the larvae feed. Sandy meadow land? in the vicinity of vineyards should be broken up and cultivated to annual crops, and in this work the co-operation of vineyardists throughout a neighborhood is especially important. Bagging grapes as soon as the fruit has set is often practiced, and affords protection not only against further injury from the rose- chafer, but also from the grape berry moth, the grape curculio, and fungous diseases of the fruit.— (Farmers' Bui. 284, U. S. D. of A.) The Grapevine Root-Borer. — This insect has been recognized as an enemy of the grape in the United States for more than fifty years. It is capable of doing serious damage to grapevines and the slight attention which it has received in the past is no doubt due in a measure to the obscure appearance and habits of the insect through- out the four stages that compose its life-cycle. So inconspicuous is the insect itself, and its manner of working, that a vineyard may be suffering greatly from its attacks and yet those who have the care of the vines remain entirely ignorant of the cause of the trouble. The eggs are small, of a dull color, and the female in ovipositing scatters them promiscuously about in the vicinity of the vines. The larvae, or borers, feed beneath the ground on the roots of old vines, usually some distance out from the base of the roots. No chips or castings are thrown to the surface to direct attention to the injury which is being done. The roots of one-year-old and two-year-old vines are rarely attacked, so that in the work of planting out vineyards the borer is not likely to be seen. The transformation from larva to adult takes place within an earth-covered cocoon that is hidden in the ground, often six inches or more from the root where the borer fed. The adult moth flies by day, but in size, color and manner of 76 INSECTS AFFECTING VEGETATION flight it so closely resembles some of the common wasps of the genua Polistes that a close scrutiny is necessary in order to make sure that the insect under observation is a moth and not a wasp. As a result of these peculiarities the insect may be abundant in a locality and yet remain unnoticed by grape growers. Vines when attacked by the borers do not often die as a direct result of the injury sustained, but may become so enfeebled that the annual growth of bearing wood is meager and the yield of fruit very small. It is in the larvae stage alone that the insect is capable of doing any injury. When first hatched the larvae are very small, being only about one twenty-fifth of an inch in length. They are whitish in color with brown heads, and are sparsely covered with stiff hairs. When full grown some specimens attain a length of one and three- fourths inches. As soon as the young borer is out of the egg, which, as stated, is on the ground at the time of hatching, it begins to work its way downward through the soil, evidently trusting good fortune to guide it to a grape root. That the borers can survive at this early age for several days with but little food was shown by placing half a dozen in a small bottle, where they lived for three days and then escaped by tunneling through the cork stopper. During the three days' confinement they had no nourishment except what they might have extracted from the dry cork, which wTas most likely very little. The borer, after finding the root, first eats its way through the outer bark and then begins to excavate an irregular burrow, which at first is confined to the softer portions of the bark. At the begin- ning, this burrow may encircle the root several times, but later, as the borer increases in size, it is made to run with the grain of the wood and may be extended either toward or from the base of the root. The diameter of the burrow is increased with the growth of the borer. The females, when they are engaged in egg-laying, can very readily be approached and killed by striking them down with a paddle-like instrument or board. If a watch is kept about infested vines from the middle of July to the middle of August the females may be seen and killed in this wTay. It is by the thorough cultivation of vineyards that the greatest good is likely to be accomplished in the way of reducing the ravages of this insect. Observation has shown that from the middle of June to the last of July the insects are transforming from the borer stage to the adult stage within cocoons which are located just beneath the surface of the ground in near proximity to grapevines. If, during this period the ground about the vines is thoroughly cultivated, most of these cocoons will be either thrown to the surface where the pupae wuthin will perish, or be buried so deeply that the moths escaping later will not be able to work their way out of the soil. The cocoons are usually found a foot or more away from the vines, a fact that enables the cultivator to reach most of them without the necessity of working up entirely to the vine, which is a difficult thing to do where some methods of pruning are practiced. As a matter of course, the cultivation will give the vines increased vigor, enabling them more ENTOMOLOGY 77 readily to withstand and overcome the attacks of root-borers and other insects.— (W. Va. Bui. 110.) The California Grape Root-Worm.* — This is an insect that at- tacks both the roots and the growing parts of the vine above ground. It has been known to attack the leaves of the vine in this State for a good many years, but until a year or two ago it was unknown as a root feeder. It is similar in its life history and mode of attack to the well-known grape root-worm of the Eastern States, which is one of the worst pests that the vineyardists there have to wage war against. Our species has been doing considerable damage during the j^ast two or three years, and it promises to be an important enemy of the vine in California. While the insect has occurred on vines in the State for the last thirty j'ears it seems not to have spread so rapidly as might have been expected, judging from the experience with the same insect in Europe and its related species in the Eastern States. It is difficult to explain just what may account for this. Since the greater part of the insect's life is spent in the ground, it is in this stage that conditions would be most likely to influence its progress. Such conditions might be found in the kind of soil, the cultivation of the soil, the variety of vines and the great depth of the root systems in some of our drier sections. Again, the true importance of the insect's work has never been appreciated in the State hitherto, since it has been known as a leaf feeder entirely. Vines, therefore, may have shown a general unthriftiness due to its attacks, but be- cause the root infesting habits of the larvae were unknown the trouble may have been assigned to other causes. The young larva upon hatching from the egg makes its way to the ground almost immediately. It may crawl to the ground, as we infer from finding them pretty well scattered down the trunk of the vine, or they may possibly in many cases simply drop to the ground. As soon as the larvae reach the roots of the vine they begin feed- ing, and it is generally the smaller rootlets that are first attacked, although we have found young larvae around roots of considerable size. These smaller roots may be eaten off entirely. The larger roots are injured by the larvae gouging out long strips of the bark, which sometimes take almost any direction, but on the roots of medium size these strips are usually eaten out in a direction parallel with the axis of the root, or in a spiral direction. The frass or eaten bark is left in their paths and is characteristic of their injury. The furrows made are from one-tenth to one-fifth of an inch wide, and in cases of severe injury all the bark may be eaten away from the roots. This feeding is continued from the time they hatch in the spring until the vine becomes dormant in the fall. There are two forms of the adult beetle occurring in the State, one being black in color and the other mostly brown. There is con- siderable differences in the size of different specimens, and particu- larly in the sexes — the males being much smaller. On an average they will measure about one-fifth of an inch in length. ♦See page 321, for illustration. 78 INSECTS AFFECTING VEGETATION Many of the pupae may be destroyed by deep cultivation for a radius of two or three feet about the base of the vine. The beetles may be killed by a strong arsenical spray, or by jarring into crude oil, or otherwise captured as they are shaken from the vine. — (Bui. 195, Col. Agr. Exp. Sta.) The Grape Phylloxera. — The phylloxera occurs normally in four forms, which have been called by Victor Mayet: 1. The gall insect, or form of multiplication ; 2. The root insect, or form of devastation ; 3. The winged insect, or form of colonization ; 4. The sexual insect, or form of regeneration. The gall insect lives upon the leaves, and is the commonest form on the wild vines in the native habitat of the insect. It rarely or never occurs in California. In Europe it is found often upon American and rarely upon European varieties. It causes little swell- ings or galls upon the leaves and younger parts of the vine, which, though sometimes very numerous, do little permanent injury. The chief danger from the gall form is that it multiplies with astonishing rapidity and migrates from the leaves to the soil. Here it attacks the roots and gives rise to the root form, which is the form of devas- tation, the one which finally destroys all the vines it attacks which are non-resistant. Every insect of the root form which reaches maturity lays about twenty-five or thirty eggs, each of which is capable of developing into a new egg-layer needing no fertilization. As there are from five to seven such generations during the year the increase in numbers is extremely rapid. The most satisfactory method of combating phylloxera is the use of resistant vines, because it is applicable to all conditions and is the most economical in the end. A resistant vine is one which is capable of keeping alive and growing even when phylloxera are living upon its roots. Its resistance depends on two facts: 1st, that the insects do not increase so rapidly on its roots; and, 2d, that the swellings of diseased tissue caused by the punctures of the insects do not extend deeper than the bark of the rootlets and are sloughed off every year, leaving the roots as healthy as before. Though high resistance to phylloxera is essential in a grafting stock, there are other characteristics equally necessary. The Rotund- ifolia (Scuppernong), which has the highest resistance of any vine, is useless as a stock on account of the impossibility of grafting it with any Vinifera variety. This is due to a lack of affinity, which means a lack of similarity in structure and composition between the tissues of the stock and those of the scion. This lack, in extreme cases, results in an imperfect and temporary union, but when not excessive, only a slight decrease of vigor. The affinity is not perfect between Vinifera varieties and any resistant stock, but in the case of Riparia and Rupestris is generally sufficient to insure permanence to the union, and the slight decrease of vigor consequent often results in an increase of fruitfulness. The Strawberry Root-Louse. — Whenever numerous bare spots are found in a strawberry bed, and the remaining plants are more or less unhealthy, failing to mature fruit properly, the owner will do ENTOMOLOGY 79 well to examine it for the root louse. If the bed be infested, open- ings of ants' nests will usually be found very numerous and large numbers of small brown ants will be seen among the plants. Upon pulling up an infested plant many of the roots will be covered with clusters of the little black plant lice. The root lice, or aphids, found on the roots during summer and early fall are very small insects only about one-twentieth of an inch long. They are of a deep bluish-black color, and somewhat pear- shaped, tapering toward the head. There are usually four genera- tions. The pest may be spread in three ways: (1) by the aphids or eggs being introduced upon the plants in setting the beds, (2) by the spread of the winged lice, and (3) by being transported by ants. Undoubtedly the species has been most generally spread by infested plants, either from the nursery or from old beds. It is evident that land infested with aphids should not be immediately replanted with berries, for through the care of the ants, a few eggs or viviparous females are very apt to survive either in ants' nests or upon stray plants growing around the border of the field. If it is desired to replant berries after a single year's rotation the land should be put in several crops which require constant culti- vation. Corn and melons are commonly infested with aphids which are attended by ants, and these crops should therefore never be fol- lowed by strawberries, where there is any possibility of the root-louse. As the aphids and their eggs are readily transported on young plants it is of the utmost importance that the plants be secured from sources known to be free from the pest, or, if any doubt exists on this point, that they be thoroughly disinfected by the dipping of the plants in a tobacco decoction or' by fumigation with hydrocyanic acid gas as for San Jose scale. — (Bui. 49, Del. Exp. Sta.) The Strawberry Weevil. — Just before the blossoms of the straw- berry expand they are attacked by an insect which severs them from the stem. This insect is the strawberry weevil, and the severing of the buds is accomplished by the female in the process of oviposition. The weevil first deposits an egg in the bud and then punctures or cuts the stem below it so that in a few days it drops to the ground. Within the severed bud the larva hatched from this egg develops, and transforms to the pupa and afterwards to the beetle. The strawberry weevil measures only a tenth of an inch in length, and is provided with a slender, slightly curved snout, about half as long as the body, to which are attached its jointed antennae. The color" varies from nearly black to dull red, and each elytron or wing-cover is ornamented just behind the middle with a dark spot surrounded with whitish pubescence. The presence of the weevil in strawberry beds is manifested by the decreased number of blossoms and the severed buds and stems, the diminutive size of the beetle protecting it from general observa- tion. Nor is the destruction of the buds likely to be noticed until some time after the insect has been at work. Hence it happens that injury, even over wide areas, is often attributed to hail, frost, or to some other cause than the right one. Appearing, as the insect cO 80 INSECTS AFFECTING VEGETATION often does, in great numbers almost from the outset, its injuries are severe even in seasons when only a moderate percentage of a crop is lost, because the blossoms chiefly injured are the earliest, and con- sequently the shortage is largely in the early fruit, or that which commands the highest market price. Injury, as already stated, is due to the work of the female in the course of oviposition. Selecting an unopened, nearly mature bud she perforates with her beak the corolla or outer husk and turn- ing about deposits in the hole thus formed a single egg. She then crawls to the pedicel or flower-stem just below the bud and with the microscopic but scissors-like mandibles at the extremity of her beak deliberately punctures or cuts it in such manner that the portion containing the bud hangs by a mere shred of the epidermis and soon afterwards falls to the ground. The object attained by the parent insect in puncturing the stem is twofold: (1) The development of the bud is arrested, and its outer envelopes of sepals and petals remain folded, thus retaining the eggs or growing larvae of the insect and the pollen on which the latter feed; (2) the bud falling to the ground is kept moist, whereas if permitted to remain upon the stem it would eventually have become so dry as to prevent the development of the insect within. Ordinarily a single larva inhabits a bud, but in exceptional cases two individuals may develop in one bud. — (Cir. 21, Rev. Ed. U. S. Dep. of Agr.) Owing to the difficulty of contending with the insect when once it has invaded a strawberry bed, it is necessary to have recourse to preventive measures. A nearly perfect preventive consists in cov- ering the beds. This covering, which may be of muslin or some similar light material, if properly applied will not only exclude the weevil and other noxious insects, but will secure immunity from frost and is moreover a positive benefit to the berries, which ripen a week or ten days earlier and are superior also in quality and size. Whatever covering is employed should be put in place over the beds at least a week before the appearance of the first blossoms and may be safely removed as soon as the first berries are ready for market. Pistillate plants, or those which produce no pollen, require no such protection. It is obviously unsafe, in districts where the weevil is known to be abundant, to trust entirely to staminate varieties of berries. It is advisable, therefore, to grow chiefly pistillate varieties and just as few staminates as are necessary for the purpose of fertilization. The insects, when they become abundant, will mass themselves upon the staminate plants, where they may be destroyed by spraying and similar measures. The most satisfactory method of securing freedom from injury by the strawberry weevil is to plant very profuse-blooming varieties, and many have agreed that the following, in the order named, are the best that have been tested to secure this end : Rio, Superior, Ten- nessee Prolific and Gandy. In the same manner that the rows of staminates used for fertili- zation constitute a protection for the other rows, certain varieties, ENTOMOLOGY 81 particularly such as bloom early, may be used to protect later-bloom- ing plants. One of the best for this purpose is the Charles Downing, as it blooms early and its blossoms are exposed to the sun. By laying out beds with Downings or other early staminates on the sides that experience has shown to be most susceptible to attack — e. g., in pro- tected sunny spots or near woodland in which the beetles might have hibernated — the insects will be attracted from the other portions of the beds and can be the more readilv controlled by spraying with the arsenicals.— (Cir. 21, R. E., B. of E. U. S. Dept, of Agr.) The Strawberry Leaf-Roller. — This leaf-roller seems to be of European origin, and is one of those species which in its native home is not seriously injurious, but in its new surroundings finds conditions to its liking and frequently outruns its natural checks. At the present time it extends from Canada to Virginia and probably even farther south, and westward to the Mississippi Valley, very often in harmful numbers. It is, in the adult stage, a small moth, measur- ing with expanded wings about three-fifths of an inch. Its color is light reddish brown, the forewings streaked with wavy darker brown and white lines as shown in the figure. When the wings are folded and the insect is at rest, the dark area at the base forms a somewhat conspicuous deeper brown patch on the middle of the back. The hind wings are of a soft dark smoky gray, and both wings have long fringes. The moths fly readily during the middle of the day and run rapidly on the leaves, diving to the under side or into a fold so quickly that it requires close watching to follow their movements. They do not ordinarily fly very far where food plants are abundant, but where they are plentiful, some of them find their way to con- siderable distances, infesting new fields where clean plants were set out. This moth makes its appearance in the strawberry fields in early May. The insects mate soon after their appearance and egg- laying begins at once. The eggs are pale green, almost like the underside of the strawberry leaf in color, round or slightly oval, much flattened and about as large as the little meshes in the netting of the half-grown leaf. Larvae hatch from these eggs in from five 2, Wash. Agr. Exp. Sta.) The Raspberry Byturus. — The cause of the injury is a small brown beetle, belonging to the same family as the buffalo carpet moth and the museum pests. This one, however, has the unusual habit of confining its attack to living plant tissues, instead of feed- ing on animal fibre and tissues as its near relatives do. This small brown beetle, the Raspberry Byturus, feeds upon the young leaves and buds of the raspberry, and the larvae develop in the head upon which the berry is borne, causing the affected berries to ripen earlier, and this tends to make them small and unfit for market. Its injuries are severe, but these are usually confined to small and somewhat local areas. It probably has some insect enemies which hold it in check, in most cases, as it seems to disappear after a few years of abundance, during which it inflicts severe injury on red raspberries. The beetles are pale yellowish-brown in color when they first emerge, but get much darker in a few hours. They often fly to the tender leaves and buds of the raspberry bushes be- fore they have assumed their normal color, and immediately com- mence feeding on the tender leaves, and on the under sides of lone buds, and on the inner contiguous sides of clustered buds. In the latter case where the buds are touching each other, they do the most damage, as they often eat out the sexual organs of all the adjacent buds in a cluster. Most of the tender leaves are partly skeletonized, and sometimes completely so, when the beetles are plentiful. These worms are plump and cylindrical, slightly tapered at each end, and nearly one-fourth of an inch in length when full grown. They are white, each segment having on the back a broad, pale, tawny yellow band, occupying more than half its surface, and being also furnished with a few short, erect, whitish hairs. 'Spray heavily with arsenate of lead just before the emergence of the beetles and this will destroy most of the beetles and materi- ally lessen their injury to the flower buds. In connection with this, thorough cultivation late in the fall, close up around the bushes, will destroy many of the pupae, or expose them to the freezes and thaws of winter, thereby causing their destruction. Spraying with kerosene emulsion is only to be recommended where the beetles are already very numerous, and the spraying with ar- senate of lead has been deferred until after the beetles have appeared in large numbers; even then, the arsenate of lead will be fully as effective and last for a much longer period, but in extreme cases the two may be used together. Bordeaux may be added for fungous diseases, and will help to hold the arsenate of lead on the foliage and buds, making the spray slightly more efficient than if arsen- ate of lead were used alone. — (Bui. 202 Ohio Agr. Exp. Sta.) The Tree-Crickets. — Many times one finds long rows of punc- tures on the sides of raspberry and blackberry canes, and also on the new growth of peach trees. When such a twig is split along the row of punctures, each hole is found to contain an egg, the egg of a tree-cricket. The rows vary in length from one to several ENTOMOLOGY 91 inches, and sooner or later usually cause the twig to split open, weakening the twig if not killing it outright. The cricket that causes all this trouble is a delicate little creature, light colored, sometimes with dark markings, and provided with good sized wings. It is perfectly harmless except for the habit of placing its eggs in twigs in the autumn. In fact it is said to feed largely on plant- lice and therefore to be our friend. The only pratical method of combating these insects is by cutting out the affected canes and twigs and destroying them by fire. If not at all numerous, they may safely be ignored. — (Bui. 24 Mich. Agr. Exp. Sta.) The Currant Span-worm. — Unlike the larvae of the imported currant worm, those of the span worm are measuring-worms or loopers, sometimes called inch-worms. All are familiar with cater- pillars of this class. The currant span-worm often comes in large numbers, and devours the foliage very rapidly. The caterpillar, when full grown, is marked with, three longitudinal yellowish stripes and by several spots on each segment. The pupal stage is passed under the surface of the soil, and the delicate, yellowish moth lays the eggs in summer for the brood of larvae which will come out next spring about the time that the foliage becomes well grown. This insect works also on gooseberry. There is but one brood each year. When the larvae are noticed early before the fruit is more than just set, paris-green applied in the ordinary way, will kill them very nicely. After the fruit gets started, use hellebore in place of paris-green, because it is much safer. The Imported Currant-worm. — The common currant-worm is the larva or false-caterpillar of a saw-fly. Sawr-flies belong to the same order as the wasps, but in place of stings, they are provided with saw-like implements with which they are enabled to cut slits in the foliage or bark of vegetation. They are mostly small, thick- waisted creatures with four wings, the color being often black or yellowish. The saw-fly under consideration, lays its eggs in rows along the ribs of currant or gooseberry leaves where they absorb water and become swollen, afterwards hatching into small, whitish false- caterpillars, which turn green after a time. Later, many black dots appear on the body, and just before they are ready to spin up in a cocoon, they change once more to green with yellowish ex- tremities. The larvae of saw-flies may always be distinguished, from those t)f moths and butterflies, by the number of feet, there being always six true, jointed legs and twelve to sixteen false legs; while true caterpillars with very few exceptions have only ten false legs. When full grown the larva spins a cocoon, usually in rubbish near the base of the plant, although they may go beneath the sur- face of the soil. The cocoon is oval in form and thin, being papery in texture. There are two broods a year but they are not well de- fined. The adults come out at various periods, necessitating a repe- tition of the measures required to kill the larvae. The time honored 92 INSECTS AFFECTING VEGETATION practice of dusting with hellebore will ordinarily prove sufficient if the hellebore be fresh. After the fruit has been picked, arsen- ites may be used to advantage. See directions for using paris-green. The Native Currant Saw-fly. — Another species of currant- worm which is a native of America is sometimes met, especially in the North. It occurs somewhat later than the imported species and the larvae are green. The same remedies as those used against the imported species will apply. The Currant Aphis. — Green lice on the under side of currant leaves, causing the leaves to turn reddish in color and to have an irregular surface. Spray with kerosene emulsion or whale-oil soap solution. This spray kills only by coming in contact with the lice, therefore direct it against the under side of the leaves. — (Bui. 24 Mich. Agr. Exp. Sta. ; Bui. 51 Mont, Agr. Exp. Sta.) Imported Currant-borer. — The currant and gooseberry are often attacked by a borer that works in the center of the branch, tunneling down quite a distance and interfering seriously with the development both of the foliage and of the fruit, and eventually bringing about the death of such tunneled wood. Stems contain- ing borers show the presence of the invader by wilted and stunted foliage early in the season. The larvae after feeding on the pith and central part of the stem until autumn, pass the winter in the tunnel. In the spring when the plant starts to grow the larvae are awakened to new activity and quickly complete their growth. Before changing to pupae they eat their way almost through to the outside, plug up the hole loosely and retire. The pupal stage is entered upon and in June the adult moths come out to the open air. In this stage the insect is very beautiful, being a little less than half an inch long, slender, and brilliant black and yellow in color. The wings are only partially covered with scales, the uncov- ered part being transparent. For this and other reasons they are placed among the group of moths known as clear-wings. They so closely resemble wasps that one hesitates to handle them without careful examination. The larva possesses feet like those of most moths. When the foliage commences to expand, the mutilated stems can be distinguished by the sickly appearance of the leaves. Cut out all tunneled stems below the lowest part of the tunnel, and burn them. If this practice be constantly followed up, the bushes can be kept fairly free from this borer. The Native Currant Borer. — Curiously enough, we have two borers working in the currant, one belonging to the clear-winged moths, imported from Europe, and the other a native insect belong- ing to the beetles. The adult beetle is from three-sixteenths to one- fourth of an inch long, brown in color, with the posterior half of the wing-covers darker than the rest of the body, and with two whitish spots on each wing-cover. The larvae or grubs of this beetle are footless, and work very much as do the imported borers, except that usually several work together instead of singly as in the case of ENTOMOLOGY 93 the other. The same remedies apply as in the case of the imported species. — (Bui. 51 Mich. Exp. Sta.) See Apple Insects. INSECTS INJURIOUS IN CRANBERRY CULTURE. The Blackhead Cranberry Worm. — This is perhaps the best known and most uniformly injurious of all cranberry insects and is locally known as the vine worm in Massachusetts and as the fire worm in New Jersey. As a larvae (worm) it is a deep, rather velvety, green, slender little caterpillar, not over half an inch long- when full grown, and with a shining black head and neck. The adult is a small moth or miller with narrow, dusty-brown wings that measure less than half an inch when expanded and seem much smaller because they are so slight. More closely examined the fore wings will be found to have alternate light and dark gray- brown shade bands, obliquely arranged. The moths first appear on the bogs in early June, continuing until nearly the end of the month, and again late in July, continuing into August, when they disappear for the season. These eggs are flattened, disk-like, and less than half the size of an ordinary pin head, but their bright yellow color makes them easily visible against the green of the leaf, even without a magni- fier. There they remain throughout the winter, whether the bog be dry or flowed, and the little caterpillars hatch from them in spring as soon as the temperature reaches an average of about 60 degrees. Many of the eggs perish during the winter, but where the vines are uncovered in sheltered spots they hatch out little worms about the time the vines themselves are making a start. For a day or two the wTorms nibble on the under surface of the old leaves or may even burrow into them and then make their way to the tip of an upright, where they spin together the edges of the new leaves. The bog at the beginning of July shows very plainly the ef- fects of the insect's attack in brown tips that are everywhere notice- able; and every brown tip at this time means a barren upright. Next the leaves drop and the burnt appearance disappears for a few days, but this is only to give way to another series of spun-up tips which resemble those of the early brood, but with a difference. The vines are now in full foliage, full of buds and almost ready to bloom. Unlike those of the first brood, the worms of this second brood are not content to spin up only a single tip ; they gather into their web everything within reach. Two or three sprays with all their buds may be included and every chance for fruit destroyed. In fact, the buds, flowers, and very young berries are eaten by preference, and the injury to the crop is out of all proportion to the amount of plant tissue actually devoured. So, also, instead of eating up a leaf entire, the worms take a few bites here and there until, toward the end of July, the bog appears as if it had been burnt over, justifying the term fire-worms for the insects. The Yellowhead Cranberry Worm. — The common name here used describes the most conspicuous difference in the larval (worm) stage from the preceding species, and is employed in preference to 94 INSECTS AFFECTING VEGETATION the term vine worm under which it used to be best known in New Jersey. In this species the eggs are not on the bogs during the winter. On the contrary, the moths themselves hibernate in any shelter they can find — in cranberry houses, barns, or other build- ings; under bark or bark scales on trees, and in numerous other places where they may find protection from the direct influence of the weather. At this season the moths are uniformly slate gray, inconspicuous, much broader winged than the moth of the black- head worm, apparently much larger in every way. They are on the wing as soon as vegetation starts in spring and are ready to lay their eggs during the latter part of April and early May. They prefer cranberry if they can get it; but if not, make a shift with huckleberry or some allied plant, or even with apple. Wherever cranberry vines run up on the dams above the water line, or are otherwise not submerged, eggs are laid on the underside of the leaves. These eggs resemble those of the blackhead species so closely that, except for their fresher, brighter appearance, no dif- ferences can be observed even with a good hand lens. By the middle of May in New Jersey, and perhaps a little later in Massachusetts, all the moths have disappeared. This habit is an important one from the practical point of view and gives in some localities prac- tical control of the insect. The eggs hatch in a week or ten days — depending much upon the weather — the worms make their way to the tips and spin together the terminal leaves, exactly as do those of the preceding species. The yellow head is practically the sure mark to tell this kind from the blackheads. This matter of distinguishing between the two is of decided importance, because, while the feeding habits are similar, there are vitally important differences that affect remedial measures. The yellowheads are, on the whole, stouter than the blackheads, and, as a rule, lighter in color. They are also less active and, especially when nearly full grown, do not so readily wriggle out of their nests. The yellowheads grow fast, and are ready to pupate late in May or very early in June, a little before the blackheads appear. The second moths appear early in June, but are now bright orange red in color, whereas the first moths are slate gray. The second lot of eggs hatch toward the end of June, and the yellowhead worms are nearly half grown when the cranberries are in full bloom, early in July, when the second brood of blackheads has just started. They make even larger webs than the blackheads, and are even fonder of boring into the fruit. It is not uncommon to see half a dozen up- rights and runners all tied together in one large web, in which leaves, even if not eaten, turn brown and die. By the middle of July or a little later the yellowheads are again full grown and change to pupa3. The worms spin a silken cell, in which the change takes place, and the pupa is dark brown or blackish, with a little knob-like protuberance on the head case. This peculiarity makes the species easily distinguishable from the same stage of the blackheads. ENTOMOLOGY 95 The third crop of moths appears late in July or early in August and are of the same orange-red color as the second. Eggs laid by these motlis do not hatch until in August or even early in •September, and the worms that come out of them grow slowly as compared with the earlier broods. Few of them spin up more than a single shoot and few of them eat into any but the smallest berries. They also tend to become reddish in color and even striped, so that at one time they were believed to form a distinct species, described as the red-striped cranberry worm. Not until after the picking, if anything he left to pick, do these worms become full grown. Very irregularly in late September and early October they come to maturity, and now the moths that come from them are, after a dust of orange wears off, of the slate-gray color seen in spring. The application of insecticides on large bog areas where the plants cover the ground as densely as do the cranberry vines is a task no grower likes to contemplate; and provided he has control of a satisfactory amount of water there is no necessity for it. As against the yellowhead it will suffice if the water be held on the bogs until the middle of May, or perhaps a little later in cold sea- sons. By this time the huckleberry and heath plants have made a good growth and have tempted the hibernating moths to lay their eggs. Unless, therefore, the vines are uncovered at the edges or on knolls above water, the plants will be free from the first brood of worms. In the woods and on the upland plants the worms and even the moths are exposed to the attacks of birds and many preda- tory insects that never go upon the bogs; hence the adults of the first summer brood will not be nearly as plentiful as if they had bred on the vines. Only a few, comparatively, of the moths will fly upon the bogs, and even then do not usually get very far from the edges; so that the heavy, very injurious middle brood will be reduced to practically harmless numbers. The third brood, even if it does spread over a greater area, is not likely to prove troublesome, for reasons already stated. Hence, care and attention to the drawing of the water in spring will of itself suffice to keep this insect in check. If to this we add the destruction of the heath and huckleberry plants immediately surrounding the bogs, the nearby breeding places are further reduced and the bog is the more likely to remain free. As against the blackhead late holding will not of itself suffice, because the, eggs are already on the plants and will, under ordinary circumstances, hatch only under the same conditions that favor the start of vines themselves. But there is a little leeway in favor of the plants, and the eggs do hatch under water at a temperature not quite sufficient to start the vines. To hatch the eggs the proper tem- perature only is needed; to start the vines there must be also sun and air. If, therefore, a bog is tolerably level the water may be drawn from below until it just covers, and may be held there even after May 15, until the starting of the vines indicates that the dan- ger point has been reached, and then it must be drawn to avoid killing the fruit buds. Runners or laterals not bearing fruit buds 96 INSECTS AFFECTING VEGETATION will stand a quarter or even a half an inch start under water with- out danger unless the water is drawn on a very warm day, and then there is danger of scalding. The further advanced the plants the greater that danger becomes; hence great care and good judgment must be exercised when this measure is adopted. Fruit-bearing up- rights can not be safely permitted to make more than a mere start. On a sloping bog, where the water is deep at the gates and becomes shal- low at the edges, the water may be gradually drawn from the bottom so as to leave the warmer surface water, and in this way practically all the eggs will come under the influence of the moist heat that favors their development. Carefully carried out, this measure is often very effective; the warmth favors the development of the embryo within the egg, and when the worm hatches it drowns. Occasionally a specimen may bore into a leaf and so maintain itself twenty-four hours or more, but usually it stifles without getting even a bite. Sometimes badly infested bogs are completely freed by this method without apparent injury to the setting of fruit, yet at times the crop is reduced one-half by holding a little too late. In the latter case, however, the crop had been destroyed by the insect for several years in succession, and the owner was quite willing to sacrifice 50 per cent if thereby he got rid of the insect, as he did. This method should be em- ployed only when reflowing is not possible. When the supply of water is abundant above the bog area, so that a pond or reservoir may be formed, both the yellow and black- heads may be completely controlled by drawing the wTater early, waiting until all the eggs have hatched and some of the worms are nearly half grown, and then re-covering the bog with water for forty-eight hours. This method is so simple and so absolutely ef- fective that the larger growers are adopting it almost universally, and few new bogs are laid out anywhere without considering the matter of reflowage and providing for as good a control of the water as possible. Under proper control the water may be drawn from the bogs when the best interests of the plant demand it with- out any regard to insect conditions. If worms appear in any num- ber toward the end of May, the bogs are reflowed, and rarely is this necessary more than once in three years. Only when the bog area is small and the surroundings are very bad is annual reflow- age needful. For a complete effect the vines should remain cov- ered forty-eight hours, because it requires some time for the water to penetrate the spun-up leaves so as to kill the worms. Many, indeed, especially the half-grown blackheads, wriggle out, seeking to escape when the water reaches them, but those nearing maturity are less active, remaining at home until the water surrounds them and they simply can not get out. Covering the bogs should begin in the late afternoon and should be completed before next morn- ing, if possible. On a rainy day it may begin at any time, the object being merely to prevent the sun from boiling the young shoots. So drawing off the water should also begin in the early afternoon, and the bog should be practically dry the morning after. ENTOMOLOGY 97 Incidentally this reflowing will rid the bog of numerous other pests and may make a material impression on the girdle worm where that is abundant. The importance of a sufficient water supply has come to be so generally recognized among advanced growers that in New Jersey miles of ditches tap streams far away from the bogs, and in Massa- chusetts expensive pumping machinery has been installed to raise water in large quantities to high-bog areas. It is sometimes possible to use the upper one of a series of bogs as a reservoir, holding a full head of water as late as it is safe to reflow the lower bogs of the series which have been drawn early. In one series of 100 acres, divided into 5 sections by cross dams, a fall of about 10 feet is utilized to reflow all save the uppermost section, and this practice is possible in almost every case where water is avail- able. Sometimes it happens that bogs can be neither winter flowed nor reflowed, and the application of insecticides becomes an absolute necessity. Only arsenics are to be relied upon for good results, although for a long time tobacco was and in some parts of Massa- chusetts is yet the main reliance. It follows from what has been said concerning the habits of the worms that when once they have spun up the tips and are feeding in their cases they are practically beyond the reach of our common insecticides, and that is particu- larly true of the first brood. If there is reason to believe from past experience, or because eggs have been found on the plants, that the early brood will be numerous, spraying must be done just as soon as the vines make a start or not later than the date when the first spun-up tip is seen. The object is to get the poison into position before the leaves are spun up, so that the worms may find their first meal poisoned. If spraying for the first brood is omitted, that for the second brood should be timed in the same way, and, because the worms now spin up a greater amount of vegetation, the chances of killing them off are greater. All things considered, the best insecticides for use on cran- berry bogs is arsenate of lead, either in the paste form as sold by certain makers of insecticides or made up by dissolving separately 4 ounces arsenate of soda and 7 ounces acetate of lead in water enough for that purpose, then combining the solutions in a tank to which 50 gallons of water may be added. If the paste arsenate is used, Impound in 40 gallons is better. Any sort of machine or pump may be used and any nozzle that makes a reasonably fine spray. The point to be aimed at always is the terminal growth, because it is there that the insects feed. Nothing will be gained by driving the mixture into the body of the vines, especially if they are long and densely matted. The conditions on the bogs vary so much that every grower must determine his outfit according to his own needs. In some cases horses can be used on the bogs to draw a geared machine of large capacity; in others they are out of the question; and so the size 98 IX SECTS AFFECTING VEGETATION of tank from which the spraying is done and the way in which it is mounted must vary according to circumstances. It may under some conditions be more satisfactory to apply a dry insecticide, and for this purpose there are now several duct sprayers and powder guns on the market. By means of a fan blower a fine powder can be rapidly and evenly distributed over a large area, and this would naturally lodge just where it was needed. A good mixture for such application is 1 pound of fine Paris green to 10 pounds of dry hydrate or fresh air-slaked lime. The lime should be sifted, thoroughly mixed with the Paris green, and the combination applied while the vines are slightly moist. The Cranberry Tip Worm. — This is a minute orange-red or yellowish grub about one-sixteenth of an inch in length, found in the growing shoots, whether uprights or runners. It is com- paratively rare on Cape Cod and is not common on all the New Jersey bogs, though more plentiful there than anywhere in Massa- chusetts. It appears on the vines soon after they make a start, and the first indication of its presence is when the small leaves of the tip cease to unfold and become bunched into a compact, bulb-like mass. When this mass is opened, from one to five, and usually two or three, of the little grubs will be found at the very heart of the growing tip, feeding upon the juices and completely checking growths. If it is a runner that is attacked, it is destroyed; if a fruit-bearing upright, the flower buds come out below the infested tip and no harm is done to the crop. But the insects continue to appear on the bogs at intervals throughout the season, and the danger is that the late-tipped uprights will form no fruit buds for the next year. The little grub is rather a helpless sort of a creature, without legs and even without distinct jaws; but it has on the underside of the body a little horny process or breast bone by means of which it scrapes the plant tissue until the cells break down and their con- tents may be absorbed. In about ten days it reaches full growth, envelops itself in a thin, white, silken cocoon, and two or three days thereafter changes to an adult — a minute, two-winged fly or midge whose wings when expanded measure less than an eighth of an inch from tip to tip. The male is quite uniformly yellowish- gray and inconspicuous, but the female has the abdomen deep red, the upper surface of the body gray, the sides yellowish, the head and eyes black. She also has a slender, extensile tip to the abdo- men, by means of which the minute white eggs are laid in the very heart of the bud. After the fly has emerged from one of the infested cranberry tips the leaves that were massed together turn red or brownish, die, and break off, leaving a stub above the fully developed leaves. If the tips are killed early in the season fruit buds may form at the axils of the leaves, or one or more little spurs may start lower down on the shoot, at the tips of which normal fruit buds may de- velop. On new bogs, with young, vigorous vine>, the earlv broods ENTOMOLOGY 99 cause no damage at all and the lale broods very little. On old bogs, with long vines, the earlier broods do little harm, but the later broods materially injure the crop prospects for the year following by preventing the set of buds on the injured uprights. Strictly speaking, no direct remedial measures are known. It is not known positively how the insect passes the winter; hence control can not be attempted at that season. The worm never comes within reach of our ordinary insecticides, and therefore di- rect attack is not possible. Since the loss of the tips attacked in spring does not injure the crop of that year, the effort must be to keep the vines in such vigor that they will set fruit buds on laterals and at leaf axils when the direct tip has been lost. How this vigor- ous growTth is to be obtained the grower will be best able to deter- mine. This insect is not confined to the cranberry, and in fact breeds much more abundantly on loose strife and on some of the heaths. Therefore, where the species is troublesome, those plants should be kept down on the dams and other bog surroundings. Tip worms occur on both flowed and dry bogs, and reflowing does not reach them; but as they first occur on flowed bogs around the edges, the inference is that the winter is passed on the upland, on or in some one or more of the alternate food plants. This would make the destruction of such plants an effective measure. The Cranberry Span-worm* — In some sections of Cape Cod certain span, inch or measuring worms occasionally become in- juriously abundant, and the most destructive of these is the species above named. The parent moth is much larger than any of the other forms found on the bogs, the broad fore wings expanding IV2 inches or thereabouts. In general color it is pale ash gray, sprinkled with black, and both wings are crossed diagonally by black lines and shades. The lines have a tendency to become toothed or scalloped, and the wing margins themselves are also a little notched. The worms first appear on the bogs in June and be- come full grown by the end of that month or early in July. They are then rather more than an inch long; slender, smooth, livid gray caterpillars with a deeply indented head and a long, pointed anal plate. They have three pairs of short legs close behind the head and two pairs near the anal end. When they walk, they first stretch out at full length, take hold with the anterior legs, then bring the jmsterior pairs close to the others, the middle of the body forming a loop. This mode of progression gives them the common name "loopers" in addition to ithose already mentioned. At rest or when not feeding, the caterpillars hold fast by the anal legs only, and stretch out the remainder of the body at an angle, and so rigidly that they resemble leafless bits of vines. On a section of bog on which they have been feeding the observer may stand in the midst of thousands of them and see none until something starts them into motion; then it appears almost as though the entire bog was alive. * See puge 645, for illuetration. 100 INSECTS AFFECTING VEGETATION "When full grown they bury themselves a short distance be- neath the surface and change into rough, brown, rather stubby pupae, from which the moths emerge a few days later. The second brood of caterpillars matures early in August, and pupation begins before August 9. Though worms will continue to be present in numbers until after the middle of the month, the moths appear at its end and in September. There seems to be no regularity in the appearance of these insects. In some years they are not seen at all ; in others they may be locally abundant, and only occasionally do they seem to occur everywhere in great armies. Usually they start from some point near the edge of the bog, spread out a little, and then move in an almost direct line ahead. Sometimes the beginning is nearer the center, and the eating may be in all directions from a given point where some groups of eggs were laid. It is the first brood which, as a rule, starts near the edges. The second brood starts from in- side centers, and wThen these are numerous the boundaries of the individual broods become lost, and, the masses uniting, an army is formed which, as it advances, plays havoc with the crop. Not a green thing is left on the vines, and in a few days acres may change from green to brown ; from a smiling promise of a full crop to the barrenness of desolation. Being an open feeder upon the foliage, this span worm is susceptible to arsenical poisoning and unless the bogs can be rapidly reflowed and as rapidly laid dry, spraying or dusting are the only alternatives. Where the worms are noticed when they first start, spraying the foliage just ahead of them may answer all purposes, and indeed this poisoning of their line of advance should always be done 'before treating the parts already infested. Either Paris green at the rate of 1 pound in about 160 gallons of water, may be used, or the arsenate of lead or a dry powder may be applied, as for the blackheads and yellowheads. The Cranberry Girdler. — This species more commonly known as the girdle worm, is found abundantly in all the cranberry dis- tricts, but it is seriously injurious in Massachusetts only. The larvae, which are slender, grayish caterpillars, with shining, light chestnut-brown heads, and yellowish thoracic shields, pass the winter in a torpid condition within a silken tube or cocoon, which resists the entrance of water. In New Jersey the adults are found in May, on and around the edges of the bogs; in Massachusetts they do not fly until July, and there is evidence that the worms do some feeding in spring before they actually change to the pupal stage. This change to the pupa takes place in the tube or cocoon made in the previous fall, and on Cape Cod at the latter part of May or in early June. The adult is a pretty little creature, with fore wings expanding about three-fifths of an inch, and is one of the long-snouted moths, the palpi or mouth feelers projecting well beyond the head. The fore wings are rather narrow, very pale straw-yellow in color, with smoky lines in the interspaces between the veins and narrow silvery cross bands at the outer part, near the ENTOMOLOGY 101 margin. The hind wings are much broader and of a uniform silvery gray. When the moth is at rest the wings are so closely wrapped around the body that it looks like a narrow whitish cylin- der about three-quarters of an inch in length. The young worm is very active and strong, and at once be- gins the construction of the silken tube reenforced by bits of vege- tation, in which it lives. It works about the running portion of the plants extending along the surface of the sand in the stratum of fallen leaves which always cover an old cranberry bog and from which the delicate clusters of new rootlets take their rise. Every- where over an infested area, but especially along its borders, these worms can be found in filmy silken galleries following the pros- trate stems of runners, into the surface of which they eat their way, destroying the vital part of the plant and, especially next to the base of the runners, deeply girdling the stem. They grow rather slowly, and not until November do they make their course cocoon of mingled sand and silk that serves as winter quarters. It seems probable that in Massachusetts there is only one brood of the moths which is active in July. In New Jersey, on the other hand, the moths have been found in every month from about May 21 to the middle of September. There must be, therefore, at least two broods, which develop very irregularly. With this dif- ference in the life cycle in the two States there is an evident di- vergence in food habits, for there is no such destruction of _ large tracts in New Jersey as is found in Massachusetts. That the insect is not specifically a^cranberry feeder is proved not only by the fact that it occurs not uncommonly many miles away from any cran- berrv plantation, but also by the direct evidence of an investigator who" actually bred it on the common grasses and found further that the worms would eat freely of sheep sorrel. The cranberry feed- ing habit seems to be, therefore, a somewhat local characteristic and this gives hope that by persistent work this bog variety may be in large part stamped out. An infested bog is rarely affected over its entire extent. Small areas varying from a few feet in diameter to half an acre or more are found here and there, and sometimes a little patch only a foot or two across will remain for two or three years in succession with- out becoming enlarged, but rather it will become closed up by run- ners from the adjacent healthy vines. Larger areas tend to become larger, new vines dying from the edges each year. A restart over areas so killed out is very slow, yet it does usually occur after the second year; but the growth is apt to be _ irregular and requires 6ome time before it comes again into bearing condition. It is quite obvious that insecticides are not available here, be- cause of the concealed feeding habit, and that resort must be had to more direct methods. The suggestion is therefore made that, immediately after the fruit is off, infested bogs be flowed and be kept covered for at least a week, and better two weeks. _ This should be effective against these worms and harmless to the vines. While 102 IXSECTS AFFECTING VEGETATION the ripening fruit is on, any water covering kept on over twenty- four hours would be apt to do material injury. An additional suggestion is that the actually infested area be completely burned off as soon as its extent can be determined. The vines already attacked are doomed at best, and if in destroying them the insect can be also killed the loss will be balanced by a greater benefit. For this burning a gasoline torch may be employed, and the heat thus applied directly to the point where it will be most effective. The use of the torch will also prevent setting a fire that might injure other portions of the bog, since it can be used when the vines are so wet that they will not burn under ordinary conditions. The burned-over area can be immediately reset and the actual amount of injury limited to a minimum. If burning is resorted to, it should be done as early in the season as possible and should be extended far enough to cover the entire infested portion of the bog. The Cranberry Fruit Worm. — This is another species that is much more injurious in Massachusetts than in New Jersey, though it is by means unknown in the latter State, and in some seasons and localities does considerable damage. As a rule, bogs that can not be reflowed and high and sandy bogs suffer more. The adult moth appears on bogs in ordinary seasons about the middle of July, when the berries are setting or have already set. It is probable that the moths remain on the bogs for a period of at least a month, as indicated by the very unequal development of the worms that are found in the berries in early September. The moth, with wings expanded, measures about three-fourths of an inch and is of a glistening ash-gray, mottled with white and blackish. The forewings are narrower than the hind wings, which are more smoky gray in color and have no markings. It is a shy species, not easily started during the day, and flies with a darting motion for quite long distances. It is not generally recognized, therefore, even by growers who annually lose heavily by it. When at rest the wings are folded close to the body, and on a cranberry stem, where it usually rests head down, it is not readily seen even by an experienced eye. The eggs are laid on the young berry, preferably in the calyx, just beneath one of the lobes, but they may be on any part of the berry and possibly on the leaves as well. They are very slightly convex, almost flat, round in 'Outline, pale yellowish in color, and so soft that they adapt themselves readily to any inequalities of surface. The worms emerge in about five days, and for a day or two feed on the outer side of the berry. Then each worm enters a berry, eats out the seed chamber, and migrates to another. The vacated berry turns red, shrivels up, and eventually drops. The worm, on entering its new home, carefully closes the opening be- hind it with a web of fine silk, so dense that it is sometimes difficult to see where the hole was made. In this second berry it becomes half grown, then works out through a large jagged opening and gets into a third berry, closing the point of entry as carefully as ENTOMOLOGY 103 before. By this time the season is pretty well advanced, the fruit is of good size, and, soon after the worm starts feeding, the newly infested berry begins to turn red. To the ordinary observer the fruit is ripening nicely, if early; but the grower knows better and realizes that every such specimen is lost to him. Not unusually the worm completes its growth in this berry, but if it does not it eats into a fourth. This time it makes no attempt to seal up its point of entry; very often it spins together a little cluster of berries, eating from one into the other and ruining all of them. Full growth comes, as a rule, in late August or early September, just before picking time; then the caterpillar leaves the berry and in the sand at the base of the plants spins a rather close silken cocoon, in which it passes the winter. But quite frequently the worms do not get their full growth at picking time, and emerge from the berries after they are harvested and in the cranberry house. These delayed forms make their way to any crevice or other shelter that they can find and there spin up for the winter rest. At this time the worm is rather more than half an inch in length, of a bright-green color, with a variably marked reddish tinge on the back. The head is a little narrower than the first body segment and is of a more yellowish color, except the mouth, which is brown. The ■bod}7' segments are transversely wrinkled, clothed with a few sparse, rather long hairs. As a whole this is decidedly the stoutest of those occurring on the bog as injurious species. The full-grown caterpillars winter in their silken cocoons, which they make by first rolling in the sand, gluing the particles together with saliva, and then spinning their web inside of the rough casing so formed. Pupation begins toward the middle of April with specimens that have been dry during the winter, but probably not much before the end of May or early June on the bogs. The pupa is brown, rather chunky, and of the same general form as in the species already described. Winter flowage is not fatal to these insects, and covering the bogs with water at any time after the winter cocoon has been formed would probably be ineffective. Nevertheless, as already indicated, water-covered bogs are less troubled, and it is probable that the earlier the water is put on in the fall the more effective this prac- tice will be. Indications are that if a bog can be safely submerged for forty-eight Jtiours between August 10 and 15, just before the worms reach their full growth, the great majority will be killed off. Sound berries covered for that length of time will not come to harm if the water can he put on and drawn off rapidly enough to avoid scalding. Fruits not quite so far advanced may be covered for even a long time without injury, but there is always a risk which the grower should fully consider before he acts. The vines should be completely covered before the sun beats upon them high enough to warm the water, the covering should be sufficiently deep to prevent a scalding effect, and when the water is drawn 104 INSECTS AFFECTING VEGETATION sunrise should find at least every berry above the water level, that the drying off may be gradual. A cool day would almost insure safety to the berries, an intensely hot one might cause injury, and the nearer maturity the fruit the greater the danger. Nevertheless, despite the danger, renowage is advisable, provided it can be done within the time limit given. _ If reflowage be not practiced, pick the crop as soon as it is at all practicable, so as to get as many wormy berries off the bog as may be. The worms will emerge in the cranberry house and form their cocoons in cracks and crevices or among rubbish. Give them plenty of shelter in the way of loosely piled slats, boards, or other cover, placed wherever conveniently possible, and any time during the winter clean up thoroughly, so as to reach the hibernating worms. Field mice will eat these worms. Also a liberal use of gasoline in such places under the usual precautions against fire would reach every one of them. Insecticides are possible only during the two or three days in which the young worm feeds on the outside of the berry, and the only material that offers any chance of good results is arsenate of lead. If when the worm starts feeding it finds a poisonous meal prepared its career will be ended at once. It must be remembered that any application to be at all effective must be on the berries by July 10 and must be maintained there at least a month to get most of the hatching worms. Arsenate of lead is the most lasting of all the arsenical sprays, but new berries are being added constantly as new fruit sets, and at that season growth is rapid, so that a week will add a large amount of new, uncovered surface. One^ spraying per week for three, or preferably four, weeks offers a fair chance of success by killing off the berry worms before they get into the berry. On bogs that can not be flowed the arsenate of lead, aided by early picking, will probably reduce the amount of injury materially; but on such bogs the development of the moths may occur earlier and the grower must rely more upon the stage of growth, or, better, the appearance of the moths themselves on the bog, than upon any absolute dates. The Cranberry Katydid. — One of the most destructive^ insects on the New Jersey bogs is a species of katydid, though its injuries are, as a rule, charged to grasshoppers in general. On Long Island the damage is less marked, and in Massachusetts the insect is prac- tically unknown. The injury is chiefly caused by the feeding habits of the adult of one species which chews into the berries when half to full grown, rejects the pulp, and eats the seeds. Other species have similar habits, but occur more rarely. The injured berries wilt, shrivel, and die; but when they have just been left by the katydids, the common, shorthorned grasshoppers feed on the exposed^ pulp and, being detected in this, are quite generally charged with having caused the entire trouble. One katydid may eat out several berries at one sitting, and when the insects are at all abundant the per- Front Edge of Sheet Tent and Tops or Derricks Ready to be Pulled Over Tree. Dept. of Agr. (See page 388.) Sheet Tent Ready for Introduction of Chemicals. Dept. of Agr. (See page 388.) ENTOMOLOGY 107 centage of fruit destroyed is very large; on some bogs the amount reaches almost or quite one-half the entire crop. The katydids when mature are green, grasshopper-like insects, with very long antennae, or feelers, and long slender hind legs. The fore wings are also green and are narrow, a little thickened, not used in flight. The hind wings are decidedly longer, much broader, very much thinner, almost transparent, and longitudi- nally folded under the fore wings when at rest. Fully expanded, these wings measure from 2 to 2x/2 inches between tips, and the body is about l1/! inches in length. In the male there is a little triangular area at the base of the fore wings where they overlap, and where a few ridge-like veins form a musical instrument by means of which they produce their chirping song or call. In the female this structure is absent, but we find at the end of the abdo- men a broad scimitar or sickle-shaped ovipositor, by means of which the eggs are laid. The young wingless katydids are found around and at the edges of the bogs about the middle of June, but do not mature until early in the following August. Not until they reach the pupal stage, after the middle of July, does the berry-feeding habit become developed, but from that time until the fruit is picked their fondness for this kind of food increases, and the insects themselves increase in number on the bogs. The first eggs are laid about the middle of September and the laying continues until about the same period in October. By that time the insects have disappeared and nothing more is seen of them until June of the following year. The eggs are laid chiefly in two kinds of grasses, locally known as deer grass and double-seeded millet. Occasionally eggs are laid on other grasses or plants, but never on cranberry leaves. They are laid chiefly at night on the drier parts of the bog, in the edges of the leaf between the upper and the under surface, to the number of from, one to five in one blade ; the single number is much the more usual. When deposited the egg is very flat, almost three-sixteenths of an inch long, less than half as wide, slightly kidney shaped and of a very light yellowish brown color. The disk of the egg is closely and roughly marked or netted without definite pattern. The character of the remedy to be adopted follows from the egg-laying habits of the species. Allow none of the host grasses to maintain themselves on the bogs and burn over the dams during the winter' while the bogs are flowed. From the fact that the very young katydids are never found on flowed bogs except at the edges joining the upland or at the base of the dams, it may be fairly in- ferred that the eggs do not survive the winter when kept completely submerged, so that destruction of the grasses above the water line might answer. It would be safer, however, to have the grasses out; they have no place on the bogs anyway. For burning the grasses and other host plants on the dams some one of the gasoline torches now on the market may be used. They give a very intense heat and lick up leaves and plants with 108 IX SECTS AFFECTING VEGETATION extreme rapidity. As they can be used against the wind or while the plants are somewhat damp there is practically no danger, that the fire will get away, and when the ground is frozen, the covering of leaves and stalks is burned so rapidly that no heat gets to the roots. Growers consider it desirable to keep a cover of vegetation on the dams to strengthen or prevent them from washing, and this method will destroy the egg-bearing vegetation without also de- stroying the plants themselves. The Ideal Cranberry Bog. — So much has been said of bog conditions, and bog conditions so greatly influence the abundance of injurious species of insects, that it may not be out of place to describe briefly what a bog should be to make insect control easy and certain. (1) The bog should be as nearly level as it can be made, so as to require the least possible amount of water to flow it. A bog that can be completely covered by a 12-inch head is better than one that requires 24, and when the difference in level of an area is 5 or 6 feet or more it is better to make two bogs out of it, that the lower may be reflowed from the upper and less than half the amount of water be required. (2) Make no one bog so large that more than thirty-six hours are required to cover completely, and no more than twenty-four hours are required to draw the ditch level. (3) Build a reservoir or reserve a flooded area above the level of the highest bog of a series sufficient to hold water enough to flow at least the highest bog completely. The importance of this re- quirement is so fully appreciated that miles of ditches have been dug in New Jersey to tap streams at a higher level, and many acres of swamp area have been created by raising contour lines to deepen natural basins. In Massachusetts powerful pumps have been in- stalled to pour water directly upon the bog or into a reservoir above it. (4) Adjust bog levels so that the upper one of the series can be completely emptied into the one below, and yet have the gates and outlets so adjusted that any one bog may be completely emptied without interfering with either those above or those below. It happens not infrequently that one bog needs cleaning or other attention while others do not. (5) There should be a broad, deep, marginal ditch between the dam and the bog or between the bog and upland, and this ditch should be always clean and at least partly full of water. Many kinds of insects can be altogether kept from the bogs in this way, while grasshoppers and other insects are delayed until they can fly. Then they are feeding on other things, and they do not often change the food habits of their early life. (6) The dams and the edges of the uplands should be kept as free as possible from vegetation that harbors cranberry-feeding species. Cranberry vines should not be tolerated for an instant. Huckleberry bushes are almost as bad, and these should be cleared back for some distance where bog and upland join without an inter- ENTOMOLOGY 109 veiling dam. Other heath plants are also undesirable and should not be allowed too near the bogs nor on the dams. (7) It follows from what has been said that the bog itself should be kept as free as possible from all plants other than vines, certain grasses being especially objectionable because they are used by long-horned grasshoppers as places to lay their eggs. Bogs so arranged could be kept completely safe at all time, and once properly laid out would require little outlay to keep them so. The question whether bogs should be kept wet or dry, whether there should be many or few ditches, and whether these should be deep or shallow need not be here considered at all. The dates of flowage and reflowage and other points of measurement by means of which control may be made effective have been already touched upon. The important advantages are that neither insecticides nor spraying machinery would ever be required, and the insect prob- lem would be reduced to the simplest possible terms. — (Farmers' Bui. 178 U. S. D. A.) SCALE INSECTS AND MITES ON CITRUS TREES. THE ARMORED SCALES. The majority of the important scale-insect enemies of the orange belong to the group known as armored scales because the insects be- gin to excrete as soon as they thrust their beaks into the tissues of the plant a waxy covering which protects the growing insect and forms a definite scale-like shield entirely independent of the insect itself. This group includes the long scale, purple scale, the red scale of California and the red scale of Florida (an entirely distinct in- sect), the oleander scale, the chaff scale, and other less important species. In general habits these armored scales are very similar. The eggs, which are developed in enormous numbers, may be extruded under the covering scale of the mother insect and undergo a longer or shorter period of incubation before hatching, or the young may be partly or fully developed within the body of the mother and emerge as active insects, or more properly shake off the egg envelope at the moment of birth, so that certain species appear to yield living young. The young of these different species of armored-scale insects very closely resemble each other, and can not be distinguished without careful microscopical study. While very minute, the young are yet visible to the,naked eye, and during the breeding season may be seen, by sharp inspection, running about on the leaves, twigs, and fruit. In color they are usually light lemon-yellow. They have six well- developed legs, also antennae and eyes, and are highly organized in comparison with the degraded condition soon to be assumed. After finding a suitable situation, often within a few minutes from the time of their emergence, though sometimes not for an hour or two, they settle down, thrust their long slender hair-like beaks into the plant, and immediately begin growth, the first evidence of which is the secretion of waxy filaments from the upper surface of the body, 110 INSECTS AFFECTING VEGETATION which mat down and form the beginning of the scale covering. This waxy secretion continues during the life of the insect, the covering scale being enlarged as the insect increases in size. The females un- dergo two molts, and the skins thrown off in these molts form a defin- ite part of the scale, being cemented to it closely with the wax. The female insect, after the second molt, soon reaches full size, and when fertilized by the male begins to develop her numerous progeny. The preliminary stages of the male scale exactly correspond with those of the female. After the first molt, however, the male as- sumes a slightly different appearance, being more elongate than the female at this stage. With the second molt the male diverges entirely from the female ; the old skin is thrust out from beneath the covering scale, and does not become a part of it, as with the female, so that in the case of the male insect the first-shed skin only is associated with the scale, which never becomes more than one-half the size of that of the female. With this second molt the male insect transforms to a preliminary pupal stage, in which the antennas, legs, and wings are partially developed. A third molt occurs with the male insect, result- ing in the final pupal stage, which exhibits more fully formed legs and wings than the preceding stage and also the so-called terminal style. A fourth and last molt of the male produces the perfect insect, which escapes from beneath the covering scale and can fly about. The periods between the moltings vary with different species and with weather conditions. Most of the species, however, reach full growth in from four to six weeks in summer; development is slower in winter. The female insect, having once thrust her beak into the tissues of the plant as a larva and begun the secretion of a covering scale, never moves from her position ; and, in fact, if she be removed by force is never again able to penetrate the bark with her sucking beak, and soon perishes. The opportunity for the local spread of these in- sects is, therefore, limited absolutely to the larval stage, as in this respect they differ from the Lecaniums and mealy bugs, whieh have the power to move about until nearly the end of their growing period. The number of eggs from a single female varies somewhat with the species, but may be from 100 to 500, the number being less in un- favorable seasons. The progeny from a single female in a year, if they should all survive, would represent almost inconceivable num- bers, running into the billions. It is not to be wondered at, there- fore, that plants become thoroughly infested with these insects in a very short time, especially in climates where the breeding is but little checked by the winter season. The waxy covering makes it necessary to use rather strong washes to penetrate the scale. The difficulty increases when the old scale protects a mass of eggs, as is usually the case with the species of Mytilaspis, represented by the long and purple scales; and it is not always possible with the best washes to kill all the eggs of these species, hence the necessity of spraying repeatedly to destroy the young as they emerge. Remedial operations should ba instituted as ENTOMOLOGY 111 far as possible when the greatest percentage of the scales are in a young or partly mature condition. The Long Scale. — The long scale is supposed to have originated in China, but in common with most of the other species discussed has now a world-wide distribution, being represented in practically every important citrus region. It made its appearance in Florida about 1838, and soon became a very serious pest in that State and elsewhere in the Gulf region. At its first appearance it was vastly more destructive than later on, parasitic and natural enemies having in later years kept it decidedly in check. At present it is every- where distributed throughout Florida and Louisiana in the orange and lemon groves, and also on wild orange. Strangely enough, it was a long while getting into California. About 1889 or 1890, how- ever, in company with the purple scale and rust mite, it wras carried into California on a lot of stock from Florida, but it has not de- veloped as a very serious pest in the Pacific coast region. This insect is characterized by its very elongate form ; in other re- spects it closely resembles the long scale, and also the common oyster- shell scale of the apple and other deciduous fruits. In color it is a rather rich reddish, often obscured by extraneous matter taken from the surface of the leaves or bark. It apparently requires a great deal of moisture to thrive well, and hence is apt to be abundant on oranges or other plants grown in conservatories, and this also accounts, doubt- less, for its greater multiplication and injury in Florida than on the Pacific coast. Breeding continues practically throughout the year. According to Hubbard, there are three periods in Florida when the young are especially abundant, marking in a rough way the appear- ance of the main broods, namely, in March and April, in June and July, and in September and October; the fourth, irregular brood, oc- curring in January or February. The treatment for this scale is the use of the oily washes and fu- migating with hydrocyanic-acid gas. It is much more easily con- trolled than the purple scale. The Purple Scale. — The original home of the purple scale is un- known, but it now occurs practically wherever the orange or lemon is grown. It was probably introduced into this country at an early date. It is frequently associated with the long scale, and is one of the most troublesome scale insects affecting the orange and lemon, because it is very difficult to get an application on the trees strong enough to kill all of its eggs with one treatment. For many years the purple- scale was limited in this country to Florida and the Gulf region, but some years since it was carried on Florida stock into southern California, where, fortunately, it has not yet become widely distributed. In general color it is a brownish purple, and in shape duplicates the oyster-shell scale of the apple. The life history and habits are the same as those of the long scale. The purple scale is not limited to citrus fruits, but occurs also on many other plants. Neither the gas treatment nor any of the washes is a certain remedy for this scale, except in the immature stages. Occasionally a very strong treatment will kill the eggs, but it is usually necessary 112 INSECTS AFFECTIXG VEGETATION to repeat the application once or twice at intervals of two or three weeks to effect anything like extermination. The Red Scale of Florida. — This is another scale insect of world- wide distribution. As an orange scale it is not a very serious pest on trees grown out of doors, but on trees grown in conservatories or un- der glass it is very apt to thickly infest the leaves and fruit. It has a very wide range of food plants and is one of the commonest of scale insects. This and the following species differ from the Mytilaspis scales in being nearly circular in general outline, with the molted skins in the center of the scale instead of at the small end. The color of this scale is a rich reddish brown, almost black. The central por- tion, however, is much lighter, giving the appearance of a dark ring with a light center. The number of generations can not be accurately given, breeding going on throughout the year, but undoubtedly in greenhouses and tropical regions six or seven generations are not unusual, and in subtropical regions five generations may be safely counted. It seems never to have attracted any attention as an enemy in the orange and lemon groves of California, the dry climate evi- dently not suiting it. The moist climate of Florida and the Gulf region seems more favorable to it. The Red Scale of California. — This species is entirely distinct from the red scale of Florida. Its name comes not from the covering scale, as with the Florida species, but from the fact that the body of the mature female turns a reddish brown and shows through the thin transparent waxy scale. This insect, although for years very com- mon and destructive in the groves of southern California, and enjoy- ing also a cosmopolitan distribution, has, curiously enough, never ap- peared in a destructive way elsewhere in this country. Its origin is a matter of some uncertainty. It is now widely distributed, and has undoubtedly been a scale pest in oriental countries for centuries. It is not limited to citrus plants, but may occur on almost any plant growing in tropical or subtropical regions. It is the most destructive and injurious of all the scale insects affecting the orange in Califor- nia, being especially troublesome in the districts about Los Angeles. So far no effective parasites or predaceous insects have been found to combat it. It is controlled by the oily washes, and also by the gas treatment. The young are born free, or, in other words, the insect is semi-oviparous, and therefore any wash which will kill the old scale will destroy the young also. This insect has, in California, a rather well-marked variety, known as the yellow scale. This variety does not differ in any struc- tural feature from the red scale, but the mature insect remains yel- lowish in color. This variety is attacked by quite a number of para- sitic flies, which keep it more or less in check, so that it is not, as a rule, so abundant as the red variety. The Oleander Scale. — This species is not distinctively an orange pest. It occurs on a great variety of plants and has a world-wide dis- tribution. It occasionally occurs on the lemon and orange, espe- cially in California, not apparently being so likely to attack this plant in Florida. It is a very delicate scale, with a very thin wraxy ENTOMOLOGY 113 covering, and yields readily to treatment. It frequently occurs on the oleander, and is commonly known as the oleander scale. The male scales are white and very greatly exceed the females in abun- dance. The female scales are light buff in color with a faint purple tinge, rather than white, are two or three times the size of the male scales, and rather larger also than the scales of the species already described. The fruit of the lemon and orange is often invaded by the females of this species. The Chaff Scale. — With this scale insect the molted skins are at one end of the scale, as in the case of Mytilaspis, and the scale is oval or nearly circular, as in the case of Asipdiotus. It is very apt to be clustered thickly, often overlapping on leaves or twigs and fruit, giving the surface a rough appearance, as though covered with loose chaff. In color the female scale is light straw-yellow, the female in- sect showing through, usually with a greenish tinge. The number of generations and life history correspond very closely with the species already described. As a rule, the chaff scale by preference remains on the trunk and branches, covering these portions of the plant densely before going on the leaves and fruit. This fact renders it somewhat less noticeable than the other species, and its presence may, for a time, be overlooked. The chaff scale has been destructive, so far, only in Florida and the Gulf region, having apparently been introduced from the Ber- muda Islands or some of the West Indies. It is closely allied to cer- tain scale insects occurring in the Old World, and probably came to this country from Europe or Asia. It yields to the same treatments which are advised for the other armored scales. The Orange Chionaspis. — This species occurs in the orange groves of the Eastern United States, and is also especially trouble- some in Louisiana. Professor Morgan reports that its presence on the trees causes a bursting of the bark and very ugly wounds, followed in very many cases by the rotting of the trunks of the older trees. The orange Chionaspis is found also in several of the West Indian islands, Mexico, and in most foreign countries where citrus fruits are grown. The male scales are striking objects on account of their white color, and the females are readily distinguished from the other ar- mored scales of similar general shape by the distinctly ridged appear- ance of the waxy portion. The orange Chionaspis is readily con- trolled by the same treatments advised on a previous page for the other armored scales. The Unarmored Scales. — The species to be considered in this group include three Lecaniums, the mealy bug, two wax scales, and the fluted scale. Strictly speaking, the Lecaniums are the only ones wThich secrete no covering. The mealy bug secretes a waxy or mealy powder, which covers its body, and a similar secretion in less amount is made by the fluted scale. Both of the latter species secrete very abundant quantities of wax for the protection of their eggs. The wax scales cover themselves with copious waxy secretion, which, however, attaches firmly to the body, and can not be considered as a separate covering in the sense of the scale of the armored species. The de- 114 INSECTS AFFECTING VEGETATION velopment of the different species in this group is very similar, in that they all retain the power of locomotion until nearly the end of their lives, and do not suffer the loss of limbs and the marked retro- grade development already described in the case of the armored scales. They excrete liberally the honeydew, which is followed by the smut fungus. In this group are included some of the worst scale pests of the orange and lemon, notably the black scale, the fluted scale, and the mealy bug. Not being so firmly attached nor so pro- tected by a covering shell or scale, they are as a rule more easily de- stroyed by fumigation or sprays, and they fall a more ready prey to attacks of predaceous and parasitic insects. All of the species are egg- laying. Their Lecaniums and wax scales deposit their eggs in cavi- ties under their bodies, formed by the contraction of the female in- sects, so that ultimately the mothers become mere shells over vast numbers of eggs and hatching young. The mealy bugs and fluted scale excrete a quantity of cottony fibers, which are stocked with eggs. After a certain amount of incubation, the young hatch and escape from beneath the old parent scales or burrow out of their cot- tony nests. In transformations and general life history, except in the points noted, these scale insects closely duplicate the habits of the armored scales. The Black Scale. — This scale insect is notably an olive pest, but it also attacks citrus fruits, and is quite as destructive to the latter as to the olive. It is an insect of world-wide distribution, having been an important enemy of the olive and citrus fruits in the Old AVorld as far back as we have any records. It also affects a great variety of other fruits and plants. It occurs more or less in greenhouses, and has undoubtedly been transported to various parts of the world upon greenhouse plants as well as upon the various subtropical fruits. In the United States it is especially destructive only on the Pacific coast, and while it occurs generally in Florida it has never there assumed any great importance as an enemy of the orange or lemon. It not only saps the vitality of the plants by the extraction of their juices, but also abundantly secretes honeydew, which results in a badly at- tacked plant becoming thoroughly coated and blackened wTith the sooty fungus. The adult insect is dark brown, nearly black, in color. Its char- acteristic features are the one longitudinal and the two transverse ridges. Very often the portion of the longitudinal ridge between the two transverse ridges is more prominent than elsewhere, giving a resemblance in these ridges to a capital letter H. The general sur- face of the body of this scale insect is shagreened or roughened, which will distinguish it readily, under a hand lens, from the allied spe- cies, even before the ridges have become prominent. Very fortu- nately for the citrus grower, the development of this insect is slow, and it has but one brood annually. The young, however, appear over a very wide interval of time, and this gives the appearance of more than one brood. On reaching full growth, early in the summer, the female insect deposits her eggs beneath her already much-hardened parchment- ENTOMOLOGY 115 like skin, the lower surface of the body gradually contracting until there is nothing left but the shell, covering a mass of hundreds of eggs. The eggs will hatch in a comparatively short time, but, as the females come to maturity at different dates, the young from this spe- cies are constantly appearing and spreading over the infested plants between June and the end of October. The growth, however, is very slow, and even those earliest hatched do not reach maturity until late in autumn, the latest maturing in June and July of the following year. While retaining the power of movement practically throughout its development, this scale insect is very little apt to change its posi- tion after it is once settled, or, at least, after it is half grown. There is a general migration from leaf to twig, but the scale often develops on the leaf if the latter remains vigorous and supplies it sufficient nourishment. The remedial measures for the black scale are spray- ing with the oily emulsions and the gas treatment. The Soft Scale. — This scale insect also known as the turtle-back scale or brown scale, is closely related to the black scale, but is a much softer and more delicate insect. It changes in color with age from a transparent yellow in the young to deepening shades of brown in the adult. The adult scale has a length of 3 or 4 millimeters, is turtle-shaped, and very much swollen, the body of the mother in the last stages becoming a mere cap filled with young. In the early stages the insect is thin and flat and semitransparent, so that it is scarcely noticeable on the surface of the leaf or twig. It is very com- monly found on various greenhouse plants, and has been carried to all parts of the world on such material. In climates suitable for the growth of the orange and lemon it occasionally gains a foothold on outdoor plants. It has a gregarious habit, and commonly lives in colonies, frequently covering the young limbs and the midribs of the leaves. These colonies are usually not of long duration, being soon attacked and exterminated by parasitic and predaceous enemies, the soft texture of the insect not furnishing much, if any, protection. The transformation and habits are very similar to those of the black scale. It, however, is much more rapid in growth, and, where the climate is favorable, goes through a continuous series of generations, or broods, throughout the season. It readily yields to oily washes or to the gas treatment. The Hemispherical Scale. — This scale is also distinctively a greenhouse pest, and it can hardly be considered as especially inju- rious to citfus trees in orchards. It occurs all over the world, and oc- casionally will multiply to a slight extent on orchard trees. The in- dividuals are about the same size as those of the last two species. In color it ranges from light brown in the young to dark brown, chang- ing to reddish in the old scale. The adult scale is hemispherical in shape, perfectly smooth and shiny, and this, with its color, readily distinguishes it from the other two species. The remedies are those used against the black scale. The Florida Wax Scale. — This very curious and striking scale insect secretes a white waxy covering, arranged in a very regular 116 IXSECTS AFFECTING VEGETATION geometrical pattern. It was long known from Florida, where it is undoubtedly native, its principal food plant being the gall berry. It has now been carried, however, to other parts of the world, notably some of the adjacent West Indian islands, and also to the Old World. It was imported into California on stock from Florida in 1889, and possibly earlier, but has never gained any foothold on the Pacific coast. This insect often occurs on citrus plants, though rarely in sufficient numbers to be of very great importance. The white color and striking appearance of these scales cause them often to be noted, and very natural fears of damage are excited, but as a rule the nat- ural enemies and other causes result in very few of the young reach- ing the adult stage. This, as shown by Mr. Hubbard, not only fol- lows the action of parasites, but also is due to the fact that the scale lice as they become old and gravid can not maintain their hold on the smooth surface of the lemon or orange leaf and fall to the ground and perish. The citrus plants, therefore, are not especially adapted to this insect and very rarely suffer long or seriously from it. The Florida wax scale is three-brooded, developments not being very rapid and extending over three or four months. The waxy se- cretions give an appearance to the young insect of an oval stellate ob- ject, the waxy prominences coalescing and disappearing with age. The Barnacle Scale. — This insect, which is closely allied to the last, has been found in two or three localities in Florida, notably at Jacksonville and in Volusia County, on orange and quince, and also on a species of Eupatorium. It is frequently associated on citrus plants with the Florida wax scale. It has since been found on the same and other food plants on some of the "West Indian islands and in Louisiana and California. The barnacle scale is much larger than the Florida wax scale, having an average length of 5 millimeters and a width of 4 millimeters. The waxy covering is a dirty white, mot- tled with several shades of grayish or light brown, and the division of the waxy excretion into plates is distinct, even to a late age. The development of the insect and secretion of the waxy scale covering is very similar to that of the last species described. The barnacle scale is of very little economic importance, and is mentioned merely because its presence might arouse suspicions of probable injury. The Fluted Scale. — Of all the scale insects attacking citrus plants, this species is perhaps the most notable, not so much from damage now occasioned by it as from the problems of control which it has brought to the front and the international character of the work which it has occasioned. The facts indicate that Australia is undoubtedly its original home, from whence it was introduced on Australian plants into New Zealand, Cape Town, South Africa, and California at about the same time. The evidence points to its introduction into California about the year 1868 on Acacia latifolia. It is a very hardy insect, will live for some time without food, and thrives on a great number of food plants. In California it spread rather rapidly, and by 1886 had be- come the most destructive of orange scale pests. The damage occa- sioned by it was of such a serious character as to threaten the entire ENTOMOLOGY 117 citrus industry of the Pacific coast. The nature and habits of this insect made it almost impervious to any insecticide washes, and the orange growers of California were rapidly losing heart. In 1889, however, through the agency of Mr. Albert Koebele, an assistant of this office, the natural ladybird enemy of the fluted scale was discovered in Australia and imported into California. This lady- bird, Novius (Vedalia) cardinalis, multiplied prodigiously and in a very short time practically exterminated the fluted scale, saved the State of California annual damage amounting to hundreds of thou- sands of dollars, and removed this scale insect from the roll of dreaded injurious species. The beneficial results derived from this ladybird have not been confined to California, Through the agency of this Department and in co-operation with the California State authorities, this ladybird has been sent to South Africa, Egypt, Portugal, and Italy, and in each of these countries its introduction has been followed by similar beneficial results in the control of the fluted scale. While the fluted scale, at the time or soon after its injurious rec- ord in California, gained access to several foreign countries, very for- tunately Florida and the Gulf districts remained long free from it. The first and presumably only introduction of this insect into Florida was an intentional one, though not malicious, and illustrates the risk run in importations of beneficial insects undertaken by per- sons unfamiliar with the subject. A nurseryman of Hillsboro County, Fla., hoping to duplicate against the common Florida scale insects the wonderful work of the imported Australian ladybird against the fluted scale in California, and, ignorant of the fact that the ladybird in question did not feed on any of the armored scales which he especially wished to have controlled by it, got one of the county horticultural commissioners of California to ship him a lot of these ladybirds, together with some of the fluted scale as food. The whole lot was liberated on his premises and resulted, naturally enough, in stocking some of his trees very thoroughly with the fluted scale. The infestation coming to his attention, he sent, in June, 1894, specimens to the Division of Entomology and they were promptly determined as the dreaded California scale pest. Fortu- nately, the nurseryman in question realized the enormity of his of- fense and took, at Dr. Howard's earnest suggestion, immediate and active measures to exterminate the fluted scale on his premises, ulti- mately taking out and burning the trees. It was hoped that extermination had been effected, but four years later (1898) the fluted scale was again received from the same district. In view of its quite general spread, as reported, in the im- mediate region, it seemed improbable that it could be easily extermi- nated, and the introduction of the Australian ladybird was urgently advised. During the spring and summer of 1899 the ladybird in question was successfully colonized in Florida by Mr. Gossard, with the assistance of Mr. Craw. The fluted scale in Florida evidently does not multiply as rapidly as it does in California. Furthermore, as shown by Mr. Gossard, it 118 1XSECTS AFFECTIXG VEGETATION is attacked by a fungous disease which appears suddenly in July and results in the death of from 25 to 70 per cent of the partly grown scales. We may hope that with the aid of this disease, and by means of the prompt introduction of its natural enemy, the fluted scale will never play the role in Florida which it originally did in California. The habits and transformations of the fluted scale closely parallel those of the species of Lecanium already described. The general ap- pearance of the insect, however, is strikingly dissimilar, owing to the waxy excretions from the ventral plate of the adult female insect. These are ribbed, or fluted, from whence the insect takes its name, and becomes the receptacle of a vast number of eggs, a single female being the possible parent of more than a thousand young. The waxy material constituting the egg sac issues from countless pores on the under side of the body, especially along the posterior and lateral edges. As this secretion accumulates the body is lifted, so that ulti- mately the insect appears to be standing almost on its head, or nearly at right angles to the bark. The eggs are laid in the waxy secretion as it is formed, the waxj^ fluted mass often becoming from two to two and one-half times as long as the insect itself. The young are of red- dish color, very active, and spread by their own efforts and by the agency of the winds, birds, and other insects. The female insect is, for the most part, a reddish orange, more or less spotted with white or lemon. The early stages of the male are similar to the corresponding stages of the female. Before appearing as an adult, the male insect secretes itself in some crack in the bark, or in the ground, and exudes a waxy covering, which forms a sort of cocoon, in which the transfor- mations are undergone, first into the pupa and then into the adult insect. The winged male is rather large for a coccid, and has a red- dish body with smoky wings. The rate of growth of the fluted scale is comparatively slow, and it does not normally have more than three generations annually. This insect is quite active, the female traveling and moving about very freely nearly up to the time when she finally settles for egg-lay- ing. The male is active up to the time when it settles down to make its cocoon. The fluted scale exudes a great quantity of honey- dew, and trees badly attacked by it are covered with the sooty fungus, characteristic of the black scale and the white fly. The remedy for this scale insect is always and emphatically to se- cure at once its natural and efficient enemy, the Novius cardinalis. "Where this insect can not readily be secured, the scale may be kept in check by frequent sprayings with the kerosene or resin washes. Fumigation is comparatively ineffective against it, because the eggs are not destroyed by this treatment. Spraying is, for the same rea- son, effective only when it is repeated sufficiently often to destroy the young as they hatch. The Mealy Bug.* — The mealy bug of the orange and other citrus plants is especially destructive in Florida and the West Indies. It is not of much importance in California. * fct/e illustration on page 195. ENTOMOLOGY 119 It occurs very commonly in greenhouses, and has been carried to every quarter of the globe. The insect is mealy white in color, the female attaining a length of nearly a quarter of an inch when fully adult. The edge of the body is surrounded by a large number of short waxy filaments. This insect is active in all stages and the eggs are laid in and protected by a cottony or waxy secretion, the female insect as this is developed being gradually forced from the bark, as in the case of the fluted scale. The adult winged male is light olive brown. This species is somewhat gregarious and occurs in masses in the angles of the branches and leaf petioles and about the stem of the fruit. The remedies are the emulsions and oily washes, repeated as often as necessary to reach the young as they hatch. The White Fly. — The white fly of Florida and the Gulf region is not a scale insect, but belongs to a closely allied family. In gem eral appearance and habits, however, at least in its economic features, it exactly duplicates the true scale insects. For many years this very interesting insect has been known to infest the orange trees of Florida and Louisiana and also to be a common pest on the orange in green- houses. It has been found also on a number of plants other than orange, such as viburnum, cape jasmine, and the aquatic oak of the South. These other food plants are of significance only in indicating that it may be harbored in situations near orchards in which efforts have been made to exterminate it. The first careful description of this insect and general account of its habits was given by Kiley and Howard in 1893, and from their article the data following are largely derived. The white fly is limited, economically, to the citrus plantings of Florida and the Gulf region. It is widely distributed in greenhouses, as already noted, and has undoubtedly been carried to California on many occasions, but has never gained a foothold out-of-doors. The dry hot season of southern California probably accounts for this, and may prevent its ever becoming troublesome in that region. Its origin as unknown. It first came into prominence about 1885, but probably had been present in greater or less numbers for a much longer period, and perhaps is native to Florida. While closely resembling a scale insect in its early stages, the white fly in the adult stage emerges, in both sexes, as a minute white gnat, having four chalky wings of a fine granular texture, from which fact it is frequently called the "mealy wing." This active adult condition gives the white fly a distinct advantage over scale insects in means of spread. The damage occasioned by it is greatly increased by the secretion, in the larval and pupal stages, of a honey-dew similar to that secreted by the true scale insects. This is in enormous amount, and the sooty mold which develops in it frequently covers the entire upper surface of the leaves and produces very serious effects on the vitality of the plant ; the fruit does not ripen properly, is deficient in quality and size, and keeps poorly, involving in addition the expense of washing before it can be marketed, 120 INSECTS AFFECTING VEGETATION The life round of the insect, briefly, is as follows : The winter is passed in the mature larval stage as a thin, elliptical, scale-like object on the under sides of the leaves. Early in the spring the transforma- tion to the pupal stage occurs, this stage differing but slightly from the larval in appearance. The adults begin to appear by the middle of March and continue to emerge through April. The eggs deposited by this brood require about three weeks for development, hatching into larvae from the middle of April to the 1st of May. The adults of the second brood begin to emerge by the middle of June and con- tinue to appear until the middle of July. Between the middle of July and the middle of September a third brood is developed, the larvae of which, hatching about the last of October, carry the insect through the winter. The number of eggs laid by a single female is in the neighborhood of twenty-five, and they are placed, by preference, upon new leaves, but all of the plant is taken when the multiplication of the insect makes it necessary. The young larva is active, resem- bling closely the larva of a true scale insect. The life of the adult ranges from ten to twenty days. The most satisfactory remedies for this insect, as demonstrated by Messrs. Swingle and Webber, are the kerosene and resin washes and hydrocyanic acid gas. The treatments may best be made dur- ing the winter, between December and March, and again, if neces- sary, in May, and also in August or early in September. Two or three applications may be made in the winter. The application in August is made if the sooty mold is found to be spreading to the fruit. Since the insect lives on the under sides of the leaves almost exclu- sively, it is of prime importance that the under surface be thoroughly wetted with the spray, and it is necessary that the tree be opened up by pruning. Fumigation with hydrocyanic acid gas is also a ready means of destroying this insect. It is undoubtedly kept more or less in check by parasitic and predaceous enemies, and is subject to at- tack by several fungous diseases, which may be of occasional value in preventing its undue multiplication. The Rust Mite of the Orange and the Silver Mite of the Lemon. — This mite is an enemy of both orange and lemon, affecting these fruits in a somewhat different way. For many years this mite was known only in Florida, and its injuries were notable only in the case of the orange. It is probably native to the Florida peninsula, pos- sibly having originally some food plant other than the orange. The lemon and orange groves of California were for a long time entirely free from the attacks of this mite, but about 1889 some car- loads of citrus trees were taken into California from Florida and planted, without careful inspection, in the Rivera and San Diego Bay districts. This shipment of trees brought with it, unfortunately, two or three of the Florida scale insects, and also this rust mite, which has gained a foothold in the important lemon districts about San Diego, and is now one of the worst pests the lemon grower has to deal with. For a number of years the effect of its attacks in California was ascribed to a fungous disease, and it was not until the writer vis- ited the lemon districts about San Diego Bay in 1896, and identified ENTOMOLOGY 121 the injury as due to the Florida rust mite, that its true nature was known. Our knowledge of its life history and habits and the rem- edies for it are chiefly due to the work of Mr. Hubbard in Florida. This mite develops on both the leaves and fruit, although its presence on the former is often overlooked. On the foliage the pres- ence of the mite causes the leaves to lose their gloss and become some- what curled, as though by drought. The leaves are never killed, how- ever, the attack resulting merely in the considerable checking of the vigor of the plant. The presence of this mite affects the fruit of the lemon slightly differently from that of the orange. The ripening fruit of the orange, after having been attacked by the mite, becomes more or less rusted or brownish, and the rind is hardened and toughened. While the orange loses its brilliant fresh color and gloss, the toughening and hardening of the rind enables the fruit to stand long shipment, and protects it very materially from decay. The quality of the juice is rather improved by the mite than otherwise, the mite-attacked oranges being more juicy and sweeter flavored. As a result of this, a demand grew up in the Northern markets for the rusty fruit, and good prices were obtained for it. In the case of the lemon, however, an injury to the rind is an important consideration, a perfect rind being a requisite of the fruit, on account of the numerous uses to which the rind is put and the valuable products obtained from it. The effect on the lemon is also somewhat different from that on the orange. The rind of both fruits, when attacked by this mite in the green stage, becomes somewhat pal- lid or silvered due to the extraction of the oils and the drying up and hardening of the outer layer of the skin. This whitening is much more marked with the lemon than with the orange, and, since the lemon is often picked while green, the subsequent rusting is not nearly so notable ; hence, in California this mite is known chiefly as the silver mite. If the lemon is allowed to fully ripen on the tree, however, it also becomes bronzed or rusted, but rather lighter in shade than the orange. As in the case of the orange, the rind of the lemon is hardened and toughened, but the juicy contents are not affected materially; furthermore, a silvered lemon will keep very much longer than a perfect lemon, and will bear long shipment without risk of# much loss. Until very recently the rusted lemon in southern California found no market whatever, and was a total loss to the grower. The scantiness of the crop in 1900 resulted, however, in some shipments of rusty fruit being made under the name of russet lemons, about half the normal price being obtained. Should the manufacture of citric acid assume very much importance in southern California, the mite-injured lemons could be used for this purpose. Nevertheless, considering the ease with which the mite may be controlled, there is no excuse for allowing it to maintain itself in injurious numbers in a lemon grove, since, irrespective of the appearance and value of the fruit, its work on the foliage materially lessens the healthfulness and vigor of the plant. 122 IX SECTS AFFECTING VEGETATION The rust mite avoids exposure to sunlight, and hence the lower half of the fruit is nearly always first invaded, and only gradually does the mite work its way around to the upper surface, very fre- quently a small portion exposed to the direct rays of the sun remain- ing unattacked. This gives the appearance, most prominently shown in the case of the orange, of a discolored band extending about the fruit. The multiplication of this mite goes on at all seasons of the year in the orange and lemon districts, being merely less prolific and active in winter than in summer. It has been supposed in Florida that dry weather is inimical to if, but the fact that it thrives in south- ern California would seem to throw doubt on this belief. The rust mite itself is very minute, practically invisible to the naked eye. It is honey-yellow in color, and about three times as long as broad. It is provided with four minute legs at its head extremity, by means of which it drags its wormlike body slowly from one spot to another. The eggs are circular and are deposited singly or in little clusters on the surface of the leaf or fruit. They are about half the diameter of the mother and nearly transparent in color, having, how- ever, a slight yellowish tinge. They hatch in four or five days in hot weather, but in cold weather the egg stage may last for one or two weeks. The newly hatched mite is very similar to the adult. About a week after hatching, it undergoes a transformation, or moult, requir- ing a period of about forty-eight hours, after which it escapes from the old skin, which remains adhering to the leaf or fruit for some little time. This moult brings the mite to its adult stage, in which it is somewhat darker in color than the young and opaque. No sexual differences have been discovered, and the number of eggs deposited by a single mite is not known. The entire development of the mite is short, probably not much exceeding, in warm weather, two weeks. The food of the mite seems to be the essential oil which is abundant in all the succulent parts of citrus plants, and which is obtained by the mites by piercing the oil cells with their beaks. These mites, while excessively minute, are capable of very active locomotion, moving from one part of the leaf to another, as the conditions of light and food necessitate. An estimate, made from actual count, indicates that the mites and eggs on a single leaf in midwinter may reach the enormous number of 75,000. This indicates for trees, in the active breeding season of summer, billions of mites. The mite is very readily dis- tributed by means of insects and birds. The rust mite is readily destroyed by various insecticides. The eggs, however, are much more difficult to kill, and practically no wash can be relied upon to reach and destroy all the eggs of this mite. Experience in California indicates that gassing is also in- effective against the eggs. The sovereign remedy for the rust mite is sulphur. It may be applied as a powder on trees, and, mois- tened by rain or dew, will adhere to the leaves for quite a long period, not being readily washed off even by a hard rain. When spraying is done for scale insects, the flowers of sulphur can be mixed and applied with the spray, accomplishing both purposes Curculio Catcher Made of Sheets on Frames. Used in Georgia. Dept. of Agr. Wheelbarrow Curculio Catcher Used en New York State. Dept. of Agr. ENTOMOLOGY 125 at once. A better method, perhaps, is to first dissolve the sulphur with lye, as follows: Mix 20 pounds of flowers of sulphur into a paste with cold water, then add 10 pounds of pulverized caustic soda (98 per cent). The dissolving lye will boil and liquefy the sulphur. Water must be added from time to time to prevent burning, until a concentrated solution of 20 gallons is obtained. Two gallons of this is sufficient for 50 gallons of spray, giving a strength of 2 pounds of sulphur and 1 of lye to 50 gallons of water. An even stronger application can be made without danger to the foliage. _ This mixture can also be used in combination with other insecticides. There are several species of mites which attack citrus plants, the most troublesome one of which, especially in Florida, is the one named above. Almost any insecticide will kill the adult mite, such as kerosene emulsion, resin wash, or even a simple soap wash, but unless the eggs are killed the trees will be reinvaded about as thickly as ever in the course of a week or ten days. The advantage of the sulphur treatment arises from the fact that the sulphur ad- heres to the leaves and the young mites are killed as soon as they come in contact with it. The Six-Spotted Mite. — This leaf mite or spider, is closely allied to the common red spider of greenhouses. It first made its appearance as an important orange pest in Florida in 1886. Fol- lowing the severe freeze of the winter of 1885-86, the weakened trees seemed to be especially favorable for the multiplication of this mite; it increased suddenly in enormous numbers during the dry weather of the early summer and was responsible for very con- siderable damage to the foliage of the orange. The original food plant of this mite is unknown. It was first noted on wTild orange, from which it spread to other citrus trees. It is probably a native of Florida. Like its allies, this insect is greatly influenced by climatic con- ditions, and needs for its excessive multiplication dry hot weather. Therefore, in rainy seasons it is not especially troublesome, and it usually disappears as soon as rainy weather sets in. In Florida its period of greatest destructiveness falls between February and the middle of May. This mite was carried to California a decade or more ago with Florida stock, doubtless at the same time that sev- eral other Florida citrus insects were transported to the Pacific coast. In California, however, the principal mite injury seems to be due to "an allied species, also brought from Florida. The attacks of the six-spotted mite are confined largely to the under sides of the leaves, which are covered with a fine web, be- neath which the mite feeds. The first indication of its presence is usually a yellowing in streaks and spots of the upper surface of the leaves. The under surface becomes soiled by the accumulated excrements in the form of minute black spots and by the web of the mite. On badly attacked trees the foliage curls and shrivels and the trees may lose half or more of their leaves, and similarly also a large percentage of the half-formed fruit. Being an ac- 126 INSECTS AFFECTING VEGETATION companiment of drought in Florida, part of the damage may un- doubtedly be ascribed to the effect of the dry weather. The remedies are the same as for the rust of silver mite. The bisulphide of lime is also an effective wash. It can be made very cheaply by boiling together in a small quantity of water equal parts of lime and sulphur. Five pounds of lime and 5 pounds of sulphur, dissolved by boiling, should be diluted to make 100 gal- lons of spray. Gassing is ineffective. — (Farmers' Bui. 172; U. S. Dep. of Agr.) The Orange Thrips. — This insect, a small, yellow, active insect belonging to the order Thysanoptera (popularly known as thrips), scars the fruit and curls and distorts the leaves of the orange. At the present time its control constitutes the chief insect problem con- fronting the citrus growers of the San Joaquin Valley orange belt of California, which winds along the Sierra Nevada foothills, from east of Fresno to south of Delano. This insect, the work of which was first noticed 15 or 16 years ago, has increased in numbers with the growth of the citrus industry and recently has assumed serious economic importance. Injury to citrus trees and fruit is caused directly by the feeding of both adults and larvae upon the surface of the parts attacked. This feeding may be on the young fruit, the nearly mature fruit, or the new, tender foliage, and generally takes place on all of these. The injury to foliage is generally on young leaves, but may also occur on the axillary buds. The manner of feeding of both the adult and larva of the thrips is identical, and consists in piercing the plant tissues with the sharp mouthparts with which both stages are equipped and then rasping the wound by a rooting motion of the head. The vegetable juices thus liberated from the plant cells are sucked into the alimentary canal of the insect. The characteristic marking or scabbing of the fruit so noticeable at picking time, is started when the fruit is very small — just after the petals have fallen from the blossoms. This scabbed area is small at first, but as the fruit grows and the thrips continue to feed the markings deepen and at the same time the area of injury is enlarged. The continued feeding of a large number of thrips results in the scabbing of nearly the entire surface of the fruit. Often the marking is so large and deep over a portion of the orange that it causes the fruit to be misshapen and aborted. Frequently the entire surface is scarred while the fruit is still small, with the result that it ceases to grow and falls from the tree. The orange thrips passes the winter in the adult state, and it is generally the adult form which first becomes conspicuous upon the orange trees in the spring. Although no large number of adults has been collected in hibernation, these undoubtedly pass the winter in sheltered places, such as the dead leaves and twigs forming the trash under most orange trees ; they are occasionally found on living plants and on citrus nursery stock in midwinter. In view of the success attained in reducing injury to fruit and foliage by the orange thrips, it is believed that it will be possible to ENTOMOLOGY 127 control this species in normal seasons with four applications of lime- sulphur combined with blackleaf tobacco extract. Three of the treatments should be made in the spring to free the fruit and spring growths of foliage from injury, since the more severe marking of fruit is done while the fruit is small. The fourth treatment should be made in August or September, according to season, for the protection of the later growths of foliage, and should be timed to catch the thrips when numerous, but before the leaves show much curling. The three spring applications should be made about as follows: First. Just after most of the petals have fallen from the blossoms ; Second. Ten to fourteen days after the first ; Third. From three to four weeks from the time of the second treat- ment. The dates for spraying in any given season must be timed by the abundance of thrips.— (U. S. D. A., B. E. Bui. 99, Part I.) The Red Spider of Citrus Trees. — Red spiders have been in- jurious in southern California for many years, but little attention has been given to the matter, chiefly on account of the extremely minute size of these creatures. The appearance of the fruit from trees badly infested with the red spider is very characteristic, and easily recognized when once known, but has not, as far as we can learn, been taken into consideration in the grading of fruit. Should the market come to recognize and begin to discriminate against the paler fruit, upon which the mite has been at work, the losses would become very large. Upon hatching, the creature which appears resembles the adult mite very closely except in size and in the absence of the hind pair of legs, making the number six, thus resembling insects to this extent. Many other mites are six-legged when first hatched from the egg. The young red spider at once begins to feed and is very soon ready to prepare for the change of skin which results in the assumption of the fourth pair of legs. The juices of the leaf are sucked up through a tube-like cavity between the palpi; and where each slit is made and the contents pumped out a paler spot remains. A material that is both safe and effective is the sulfid of potash spray mixture. This mixture is usually made according to the fol- lowing formula: Potash 32 lbs. Sulphur, finely ground 37 lbs. Salt 2 lbs. Water 50 gal. This makes the stock-solution which is diluted with about a hundred times as much water for spraying. The potash, sulphur, and salt may be mixed together in a large metal tub with a little water, when chemical action will at once set in and the whole mass will dissolve and begin to boil very vigorously. After the boiling has ceased, the water is added and the stock-solution is made. It is very doubtful whether the salt is of any value in this mixture, but it can at least do no harm as it is in such small quantity. This sulfid of potash is of very little value, at least at this strength, as an insecticide, but is effective enough against the active stages of the 128 INSECTS AFFECTING VEGETATION mite. In order to kill the eggs and moulting forms it will be neces- sary to make three applications, separated by intervals of one week. This will make a very clean sweep. — (Bui. 145, Cal. Agr. Exp. Sta.) The Scale Insects of the Date Palm. — To the naked eye the scales appear as small dark-grey or black specks, edged with white, At one end will be seen a small oval object, which is the first skin; that is, the skin shed by the young at its first moult. The large shield-shaped object is the second skin, and the white surrounding part is the scale secreted by the insect in its last stage. The date scale when once established, spreads rapidly, damages the foliage of the date palm and renders the fruit unmarketable, being therefore a serious menace to the industrial future of the tree under our climatic and cultural conditions. Fortunately, however, the limited size of the broods, insect enemies, the probably wingless condition of the male, and the fact that this scale so far as now known has no other food plants in this region, all tend to limit the numbers and range of the insect. For remedies see under heading of the Marlatt Scale. The female insect is from 1 to l1/^ mm. long, and secretes a wThite waxy substance but does not produce any true scale like that of the Parlatoria. The Marlatt Scale, because of its closer confinement to the bole of the palm, is comparatively harmless and to be regarded with less apprehension. To free the palm trees of these two scales, first cut back close to the bole all old leaves that are badly infested and then thoroughly go over the trunks and leaves wTith the flame from a gasoline torch. With the radical and thorough method of treatment by burn- ing at command, described above at the same time fatal to scale insects and not seriously injurious to the palms, and with a suitable law for the application of the method, there is no reason, except lack of vigilance, why the scale insects affecting date palms may not now be considered under control in Arizona. (Bui. 56 Ariz. Exp. Sta.) The Pineapple Scale. — This pest of the pineapple is a. scale in- sect, one of the Coccidse, which, because of its special fondness for this plant, has received the common name the "Pineapple Scale." These small, scale-like insects are very conspicuous, because of their color, and not easily mistaken for other forms. The scale and not the insect itself is the object commonly seen. The insect is found beneath this secretion, which serves as a shield. In the case of this insect the scale or protective armor is made up partly of a waxy secretion of the insect and partly of molted skins. The insect itself in the adult stage is quite well buried beneath the epidermis of the plant and hence the necessity of combating the pest in its early stages. The pineapple scale can be controlled by spraying where it occurs in the field with kerosene emulsion or the resin wash, 1 part to 10 of water. The cheaper and easier method is by proper preven- tive measures to keep the pest from gaining a foothold in the planta- tion. These measures are to burn all leaves where the pest is at all ENTOMOLOGY 129 evident after harvesting the crop, to dip young plants in an insecti- cide before planting, and to produce the maximum vigor and health of the plants by thorough cultivation and fertilization. In the question of the control of the insect pests and diseases of plants, no one point is more important than vigorous and clean cultivation and the proper supply of plant food and moisture. It is an accepted fact in applied entomology that a healthy growing plant is capable of offering resistance to the attack of an insect pest. (Press Bui. 10, Hawaii Agr. Exp. Sta.) The Mango Weevil. — The destructive work of the mango weevil in the seeds of mangoes was noted in Hawaii for the first time last year. The nature of the insect and its injury point it out to all persons interested in the culture of the mango as a serious pest, As a beetle, the mango weevil has a thick pair of wing-covers which, when folded together at rest, give the body the appearance of a shell. The wing-covers are much rounded and extremely hard. As a weevil, the head is prolonged in front into a beak or rostrum, bearing the antennas on its sides and the modified mouth-parts at the extreme end. The mouth-parts are formed for gnawing. In the mango weevil, the beak is short and thick and when at rest is turned back beneath the thorax in a groove terminating between the first pair of legs. The adult weevil varied from a/4 of an inch to 5-16 of an inch in length in the specimens measured. When newly de- veloped, the adult is a whitish pink in color, but soon changes to a dark brown with yellowish markings. The beetle feigns death on being disturbed and drops to the ground with the head drawn well under the thorax and the legs folded beneath the body. Its protective resemblance to coarse earth and debris is particularly noticeable. Nothing has been observed in regard to the food habits of the adult. The eggs of the mango weevil were found on mangoes from one-half to three-fourths fully grown, situated alongside a slight incision on the rind. The writer has not observed egg-laying or carefully noted the habits of the weevil as regards oviposition, but is inclined to think that the eggs in the instances seen were probably placed within the incision or cavity and later forced outby the exuda- tion of juice, an amount of which in a dried condition enveloped them. The larvae in appearance are, generally speaking, like the sugar- cane borer, that is, footless, "fleshy" grubs, light in color, with a dark headr The entire development after hatching from the egg is undergone within the seed. When fully developed, the larva con- structs a pupal cell, surrounded simply by the excrement, within the tunnel formed by feeding, and transforms to the pupa. The inac- tive pupa is perfectly white in color with the developing head, legs, wings and body-parts plainly indicated. Since the mango weevil is a special feeder on the seed of the mango, its numbers in any particular season are in direct propor- tion to the size of the mango crop for that season. That is, when the mangoes are abundant, the brood of weevils arising from the 130 INSECTS AFFECTING VEGETATION fruit will also be large in numbers. Any natural condition of climate or disease that affects the mango crop will likewise reduce the numbers of the mango weevil. The fact that the weevil during its entire development is within the seed renders the use of any insecticide impossible in combating the pest. Since also there is practically no exterior evidence that the fruit is infested, little can be done in the destruction of infested fruit during the growth of the crop. The destruction of all fallen mangoes and refuse seeds will be quite effective for the reason that the adult beetle does not leave the seed until some time after the maturity of the fruit. The burning of all refuse about the mango trees during the months from October to March would destroy many of the hiber- nated weevils. — (Press Bui. 17 Hawaii Agr. Ex. Sta.) THE NUT WEEVILS. The Larger Chestnut Weevil. — The larger chestnut weevil is considerably the larger and more robust species. The female rostrum or beak, although proportionately of about the same length as in the lesser weevil, is perceptibly more prominent because less curved, the curvature being toward the tip. It is also more widened at the base. The body measures from one-third to nearly one-half of an inch in length, and the beak of the female is often five-eighths of an inch long. That of the male is nearly as long as the elytra. The egg is small, about one-sixteenth of an inch long. It is nearly white, partially translucent, and without sculpture. The larva is milk-white, robust, fully three times as long as wide, with the dorsal or upper portion rounded and convex. The entire surface is very strongly wrinkled transversely, and there are a few very short hairs scattered sparsely over the different segments. The head is about one-fourth as wide as the widest portion of the body. It is provided with short but strong mandibles, by means of which it gnaws the kernel constituting its food. The fully devel- oped larva in ordinary resting position measures nearly half an inch. Although the larva has no true legs, it is able to crawl, slowly and clumsily, it is true, by means of the flattened lower surface, locomo- tion being aided by transverse wrinkles. The pupa is of a clearer whitish color than the larva, and shows the principal external organs of the body of the future beetle, all, except the beak, folded tightly to the body. This species, like the other weevils under consideration, is native to America and is known from Rhode Island to Virginia, the District of Columbia, southern Ohio, and Tennessee, and westward to Kansas. The geographical distribution of this and the other nut weevils has as yet not been carefully studied, but in all probability it is considerably more extensive than above stated. In some regions this species is quite generally known as the chinquapin weevil, but the investigations conducted during 1904 indicate that, although it breeds in chinquapins and more com- monly in chestnuts, it occurs in greater abundance in the larger imported nuts. ENTOMOLOGY 131 The Lesser Chestnut Weevil. — The lesser chestnut weevil has the scape of the antenna longer than in the preceding species and the first joint longer than the second. The average length of the body is about one-fourth of an inch, but the size varies, as in all of these insects. The distribution of this species extends from Canada and Massachusetts to North Carolina, Tennessee, and Ohio, and proba- bly farther westward. The investigator has seen sets of specimens labeled Arizona. Although in some localities the larger species is much more in evidence, taken all in all, the lesser weevil is the more common and is probably even more widely disseminated. The egg has not come under observation, but is undoubtedly very similar to that of the preceding, being proportionately smaller, which is true of the remaining stages. The larva is only a third of an inch long and its length is about three times its width. The body is milk-white and the head light brownish yellow, while the A -mark has a short lateral branch each side. The pupa differs from that of the larger species by size. The life history of our two chestnut weevils is so similar as to be practically the same for both species. There are, however, minor differences. These, as well as related nut and acorn weevils, hiber- nate exclusively in the larval condition and in the soil. Both make their first appearance at about the same time — with the first bloom- ing of chestnuts — but this period may vary from late in June to July, according to locality and season, or, more properly speaking, the mean temperature. At this time the beetles are found rarely and scatteringly, and as oviposition has not been observed then it is doubtful whether it begins until considerably later. What function these early arrivals fulfill is problematical. The beetles increase in number as the nuts approach maturity, or until about the middle of September or a little time before the nuts are first marketed. Then they may be seen in greater abundance, several pairs, frequently of both species, often occurring on a single bunch of burrs. As it requires about two weeks for the egg to develop, it is not probable that they are laid much earlier than when the nut begins to form. Eggs are laid singly, but many are placed in a single nut, as high as 40 or more (of the smaller weevil) in imported nuts, and as many as 9 in native nuts. The larvse when hatched feed on the tissue of the growing kernels, enlarging with their own growth the cells thus made. Rarely larvae bore through the burr. On leaving the nuts they burrow into the earth to depths varying from 2 to about 8 inches, according to the hardness of the soil. If confined in soft earth or sand they penetrate still deeper. The larval period probably lasts from three to five weeks in the nuts, and about ten months in the earth, pupation taking place within three weeks of the issuance of the beetle, the latter remaining several days in the earth before appearing above ground. The most practical remedy for nut weevils that can be suggested is the early destruction of the Avorms in the nuts by means of bisul- 132 INSECTS AFFECTING VEGETATION phid of carbon and the observance of clean orchard management and other cultural methods. It may be well to preface the discus- sion of these methods with a statement of the uselessness against nut weevils of ordinary measures employed in the control of similar insects. The value of bisulphid of carbon as a fumigant for chestnuts infested by weevils is now fully established. Although at first thought it would seem difficult for the gas to penetrate through shells so firm and compact and kill the larvae, nevertheless a prominent grower in Pennsylvania successfully uses the bisulphid, applying it when the nuts are first harvested. The dead weevil larva? are at this time so small that the average person would never detect their pres- ence, while if they were permitted to develop they would soon de- stroy the nut for food. Bisulphid of carbon has been used on the largest chestnuts grown in this country, and, since a score or two of larvae find shelter in a single nut, one can appreciate the desira- bility of prompt fumigation. The grower mentioned uses bisulphid of carbon at the rate of 1 ounce to a bushel of Paragon nuts placed in a kerosene barrel of about 50 gallons capacity and covered by sacking. After an exposure of about sixteen hours the nuts are removed, the larva? being then practically all destroyed. Some growers make a practice of plunging the nuts as gathered into boil- ing water just long enough to kill the contained insects and yet not injure the nuts for sale, after which they are dried before being marketed. This may be profitably accomplished by using a large sieve, which is filled with nuts, dipped in the water, and removed in about five minutes. Different methods are employed in drying. A good way is to place the nuts in the sun and agitate them occasionally by stirring or shaking in a bag until thoroughly dry, because if moisture re- mains unevaporated it is apt to form mildew when the nuts are pre- maturely packed for shipment. Nuts for planting should not be scalded, and care should be taken not to cook the kernels of nuts intended for sale. Some growers claim that the hot-water treatment is objectionable because the nut-shells lose a certain degree of polish, rendering them less desirable for market. Infested nuts can be subjected to a tempera- ture of between 125° F. and 150° F. without injuring them for food or for seed, and this will effect the destruction of the larva? within. Some growers of chestnuts destroy the weevils by kiln-drying. Cold storage has been employed and is successful in arresting the development of the larvae. The appearance of the nuts is scarcely different from that of those not so stored, but nuts thus treated and submitted to the writer after becoming dry were deficient in flavor, having an acrid and moldy taste. A crude form of cold storage has been successfully followed by a Virginia grower. It consists in placing nuts in the earth under the shade afforded by his house, where the soil temperature, after the nuts are gathered, does not exceed 50°. Since most insects are inactive below 51° ENTOMOLOGY 133 this has the effect of restraining their development, causing the eggs or minute larvse to die. It is always advisable to gather the entire crop, leaving none on the ground, and either place the nuts in tight receptacles or fumi- gate with bisulphid of carbon before marketing. The grubs crawl out soon after the nuts have been gathered, and as they require con- siderable moisture they will die if confined in closed barrels or boxes. The trouble is that enough nuts are usually left .in orchards or in adjoining wood or forest land to serve for the propagation of the insects the following year. In order to make the method of treatment here described thorough, it will be necessary to secure the co-operation of neighboring landowners who grow chestnuts for mar- ket and of all who own woodland containing chestnut and chin- quapin. The collection of remnants can be made by children or the un- employed. It is also profitable to allow hogs the run of the orchards to destroy what nuts remain after the crop has been harvested. In the mountainous sections of Virginia and Pennsylvania it is a com- mon practice to fatten swine on the unpicked fallen nuts. Hogs fatten on nuts and acorns as well as on corn, and without expense to the grower. The Pecan Weevil. — With the increase of pecan culture in our southern States frequent inquiry is made in regard to the cause of the holes in the nuts and during 1903 and 1904 there were reports of great injury of this nature, more particularly to pecans grown in Texas, where "considerable loss was reported, and in Georgia, where in one locality 75 per cent of the crop was a failure. A shortage has also been reported in Mississippi. The insect involved in these cases is the pecan or hickorynut weevil, a pest which is evidently destined to become one of the principal drawbacks to the cultivation of the pecan. Indeed, in many parts of the South it already divides that distinction with the husk-worm, so that it has been truthfully said that what the husk-worm leaves the weevil destroys. The beetle is about the same size as the larger chestnut weevil, from which it may be distinguished by its much duller color and by the relative lengths of the first and second antennal joints, the first joint being longer than the second in the pecan-infesting species. The larva differs from that of proboscideus in being decidedly yellow, having the head bright red and wider than long. Its cervi- cal plate "also is darker. The pupa is similar to that of the larger chestnut weevil. The distribution extends from New York to the Gulf, and west- ward at least to Iowa. The life history of this weevil, as it occurs in the pecan in the South, is, so far as can be gathered from reports from Georgia and Texas and from laboratory experiments, very similar to that of the chestnut weevils. According to the observations of Mr. H. A. Hal- bert, at Coleman, Tex., the female begins to deposit her eggs in August while the pecan is still immature, and the larva usually 134 INSECTS AFFECTING VEGETATION escapes from the nuts in the latter part of September and in October ; but most of them do not issue until the husks open, allowing the nuts to fall. In Georgia they have been found in the nuts as late as the middle of January. The same care in the selection of the site for a pecan orchard is advised as in the case of chestnut culture, with this difference, that the grower should avoid planting in the vicinity of wild pecan and hickory of whatever kind. The entire crop, also, should be har- vested or hogs should be turned in to devour what nuts are left. "Where swine and chickens have access to a pecan grove, the ground is well rooted and scratched up and there is less loss from weevils than in the previous year. Evidently both hogs and poultry devour the larvae in the ground. At the time that bisulphid of carbon was first suggested as a remedy for chestnut worms it was feared that the firm and compact shell would hardly permit the gas to penetrate and kill the con- tained larvae. Experience, however, has shown that this remedy is, successful in the case of chestnuts, and it is not impossible that it might be adapted to pecans, using a larger amount of the chemical and a longer exposure in a perfectly tight receptacle. We can as yet scarcely advise this method on a large scale, but it should certainly be tried experimentally. The Hazelnut Weevil. — Hazelnuts or filberts are injured in much the same manner as are chestnuts and pecans and by a similar weevil. Injury was recognized as early as 1841, but was attributed to other species than that under consideration. Owing to the com- paratively slight importance of the hazel as a nut tree in this coun- try, few notices of losses from weevil attack have been recorded. The weevil which affects the nut was not differentiated from others of its kind until 1884. In 1891 it was reported as badly damaging hazelnuts in Iowa. The beetle differs from others which attack edible nuts, exclu- sive of acorns, by its shorter, more robust form and shorter beak. It is about one-fourth of an inch in length, and the beak does not exceed half the length of the body. The vestiture varies from gray to ochreous, and the elytra are moderately mottled. This species occurs from Massachusetts and New Hampshire westward to Minnesota and Texas. Injury has been noted in Massa- chusetts, New York, Indiana, Iowa, and Minnesota. Of the life history little has been recorded beyond the fact that the worm issues from the side of the nut, and that paired adults have been found on hazelnuts in July. Since hazels are not cultivated in this country to any extent, no remedy need be employed other than gathering entire crops and de- stroying isolated bushes where it is unprofitable to gather the nuts. It would be quite possible, owing to the small size of the hazel plant, to control this species by jarring, as for the plum curculio. — (Cir. 99, B. E., U. S. Dep. of Agr.), The Pecan Cigar Case-Bearer. — Among the insects of minor importance that affect the pecan, the pecan cigar case-bearer is ENTOMOLOGY 135 probably met with in groves more than any other species. At times the insect occurs in such numbers as to defoliate entire trees, check- ing their growth and considerably reducing the crop of nuts. In the future this insect is likely to cause increasing damage as the acreage in pecans increases. Damage by the pecan cigar case-bearer occurs during the early spring, principally to budded trees, and is due to the feeding of the larvae on the tender buds and unfolding leaves. Where this insect is very abundant it causes injury in two ways. If the buds are backward in opening, the larvae leave the twigs where they have hibernated, and crawling to the swelling buds attack them and eat out the contents, so that the life is destroyed, and before the tree can put out its foliage the dormant buds must develop. On the other hand, if the trees develop their foliage before the larvae leave hibernation in injurious numbers, the leaves are riddled by the larvae as they come from the twigs and the wind soon whips them to pieces. The adult is a delicate little moth, ochreous in color with a wing expanse of about 1-3 of an inch. The larva is about 1-5 inch in length, brown in color. The moths emerge from the pupae during May and June, and at that time may be found among the pecan trees. The larvae upon hatching from the eggs in July, mine the leaves of the host plant, and after feeding there for some time cut out the two skins of the mine and construct the cases within which they live during the fall and winter. After the cases are made the larvae feed upon the leaves by eating through the lower epidermis and tunneling out the interior of the leaf in all directions until the mine is so large that to mine farther the larvae would have to leave their cases. Under such conditions they move and begin a new mine, so that the leaves become full of irregular rectangular patches of brown with a small round hole in the center on the underside. In feeding, the larvae carry the cases nearly perpendicular to the leaf surface. Where this insect becomes abundant enough to be injurious it can with little doubt be controlled by spraying the trees with arse- nate of lead (at the rate of 3 pounds to 50 gallons of water) when the buds are swelling — in March in central Florida and in similar climates. When the larvae attack the foliage, this should be simi- larly sprayed. Lime-sulphur mixture applied during the dormant season would undoubtedly give good results. — (U. S. D. A., B. E. Bui. 64, Part X.) The Pecan Bud-Moth. — In some orchards the depredations of this insect, combined with the damage inflicted by the case-worm, cuts off one-half the yield of nuts. The moth is about % of an inch in wing expanse ; color grey. The pupa is light-brown in color, J&- inch long and is encased in a tube of dead leaves lined with silk. The larva is slightly more than V2-inch long,# light yellowish green. The minute eggs are deposited on the under side of the leaf. Upon hatching the young caterpillars at once commence feeding on the outer skin of the leaflets, on the under side. The larva soon con- 136 INSECTS AFFECTING VEGETATION stracts a silken tube from which it does all its feeding thereafter. The damage is to the under surface only and causes a brown patch to appear. Lime-sulphur spray used as for the San Jose Scale, during the dormant period offers the best chance of success, fully combatting this pest. — (Bui. 79 Fla. Agr. Exp. Sta.) INSECTS AFFECTING VEGETABLES. GENERAL PESTS.* Before taking up in order the insects that attack the various plants grown in our vegetable gardens, attention may be drawn to a number of kinds that are general feeders, not limiting themselves to any particular varieties, but attacking almost everything that comes in their way; on that account they are the most serious foes that we have to contend against and in many cases the most difficult to keep under control. Aphids (Plant-lice). — These are minute pear-shaped, soft-bodied insects that may be found on almost every kind of plant, usually in dense colonies clustered thickly on the terminal twigs and buds, on the under-side of leaves, on stems and other parts, and even under ground on roots. Wherever situated they are occupied in the same manner — sucking out the life-juices of the plant and multiply- ing their own numbers by constant reproduction of living young all through the summer. There are a great variety of species, most of them varying shades of green in color, some are shining black, others bright red; some again are covered with waxy filaments re- sembling threads of cotton wool, and others with a dusting of a mealy substance composed of the same material. Singly they are insignificant creatures, but occurring as they do in enormous num- bers and multiplying with amazing rapidity, they are able to seri- ously injure and often to destroy the vegetation that they attack. Fortunately they are devoured by many predaceous insects, such as lady-bird beetles and their larvse and those of lace-winged and syrphus flies and other creatures washed off and drowned by heavy rains, and reduced in numbers by internal parasites ; otherwise they would in time destroy all vegetable life. Ants are usually to be found prowling about the colonies; they do not eat the Aphids, as might be suspected, but are attracted by the sweet honey-dew that exudes from them, and take them under their special protection. In gardening operations nature's checks are not sufficient, but require to be supplemented with artificial remedies such as kerosene emulsion, strong washes of soap-suds or tobacco decoction. In greenhouses they can be kept in control by burning the commercial preparation of tobacco. Ants. — These insects are often suspected of injuring the plants over which they are seen running, but as a rule they are only indi- rectly responsible. A few species, such as the large black Carpenter Ants, form their galleries in trunks of trees, posts and timber and do *Except where specially noted otherwise all extracts concerning vegetable in- sects are taken from Bui. 171, Ontario Dept. of Agr.; Ontario Agr. College, EXTOMOLOGY 137 a considerable amount of damage, but the great variety of smaller species which infest our gardens do not feed upon foliage or injure growing plants. Sometimes they may be found upon unopened flower buds, but the}' are only attracted by some sweet secretions on the surface; as a rule their presence indicates that there is a colony of aphids near by, which they take under their protection in order to obtain from them the sweet honey-dew exuded by these minute creatures. The worst injury for which they are responsible is the establishment of colonies of Aphids upon the roots of many plants ; the ants collect the eggs and take care of them during the winter and when growth is sufficiently advanced carry them to the roots and look after them during the summer, in order to have a constant sup- ply of honey dew. These colonies increase rapidly, soon check the growth of the plant and ultimately destroy it. Where ants' nests abound, frequent digging and stirring of the soil, and in field culti- vation repeated disking and harrowing, will get rid of many, or they may be treated with carbon bisulphide ; a small quantity should be poured into the entrance of the nest or into a hole made with a stick and quickly covered with earth ; the fumes will speedily kill all the inmates. It is best to perform the operation towards evening when all the ants are within the nest. This is a very effective mode of getting rid of the large colonies which make mounds of rubbish on lawns and in fields. Cutworms. — At the beginning of the growing season the gar- dener often finds in the morning young plants cut off near the sur- face of the ground that the evening before were strong and healthy. On stirring up the soil near by he may find hidden in the ground a greasy-looking caterpillar, the culprit in the case. Cutworms, so called from this habit, are the caterpillars of dull-colored night- flying moths of a great variety of species and varying to some extent in their habits. As a general rule they are partly grown at the approach of winter and hide away in a torpid state during the cold weather; when restored to activity by the warmth of spring, which causes the buds to open and the growth of plants to begin, these worms come out in search of food and attack any kind of tender vegetation they meet with. They are nocturnal in their habits and hide away during the hours of daylight under any shelter they can obtain or just below the surface in the loose soil of newly made beds. Owing to their destructive practice of cutting off a whole plant in order to devour a portion of its foliage, they do a great deal of ap- parently needless damage. After they have become fully grown they change to the chrysalis stage in the ground and in early summer the moths appear, many of them making their presence known in our houses by their attraction to light. Before very long another brood of caterpillars comes upon the scene, often more numerous and more destructive than the first. Some of them climb up into fruit trees and destroy the foliage, others attack farm crops, vegetables, grape vines, the plants in flower gardens, etc., while occasionally a single species ap- 138 IX SECTS AFFECTING VEGETATION pears suddenly in enormous numbers and sweeps like an army over the land devouring everything that comes in its way. Happily a very simple and completely effective remedy has been found for these destructive creatures. It is called the poisoned bran- mash and is made in the following manner: Mix half a pound of Paris green in 50 pounds of bran (the proportion for larger or smaller quantities is 1 to 100) ; the poison should be added to the dry bran little by little and stirred all the time till the whole is tinged with the green color, then add water sweetened with sugar, or molasses, till the mixture is sufficiently moistened to crumble nicely through the fingers. If bran cannot be procured, shorts or flour may be used, and for field work may be distributed dry by means of seed drill. The mash should be scattered about the plants that are liable to attack in the evening, and strange to say the worms will devour it in preference to their ordinary vegetable food. When they begin to feel the effects of the poison they wander off to find a hiding place or burrow in the ground and there die. Their dead bodies will be readily found in the morning just below the surface of the ground, often in surprising numbers. Young plants, such as cauliflowers, tomatoes, etc., may be protected when set out by wrapping a bit of newspaper around the stem between the root and the leaves and reaching a little below the surface of the ground. The worms will not attempt to bite through or climb over it. Flea-Beetles. — There are several species of these minute insects which attack a large variety of plants ; some confine their attentions to one or two kinds, while others are general feeders. The beetles are about one-tenth of an inch in length, oval and convex in form, usually shiny black or bronzed in color, sometimes ornamented with broad, pale stripes along the back; they all possess enormously de- veloped thighs on the hind legs by means of which they are enabled to jump with great agility and hence have acquired the name of Flea-beetles. They appear in early spring, often in large numbers, and eat small holes in the foliage of young plants, preferably the thick seed-leaves. The larvae, as far as known, feed for the most part on the roots of weeds, as well as upon some garden vegetables ; clean cultivation, especially of fence corners and bits of waste land, is therefore of much importance in the control of these and many other kinds of insects. The beetles may generally be found all through the summer when they especially attack the foliage of potatoes, tur* nips, beets, tomatoes, and many other plants. In many cases, fungous diseases, such as potato blight, find suitable places for the growth of their spores in the holes made in the leaves by these beetles. Cheese-cloth screens are very effective in warding off attacks upon young plants, such as cucumbers, etc., but where their use is not convenient or practicable the beetles may be controlled by the use of the poisoned Bordeaux mixture, the combination being effec- tive against both the insects and the fungous diseases. For tender foliage arsenate of lead is preferable to Paris green as it is not so likely to cause injury by burning. ENTOMOLOGY 139 Grasshoppers (or Locusts, as they should be called). — These are often very destructive in the later summer months, especially if the weather should be dry and hot. They are general feeders, few kinds of vegetation coming amiss to them when they are numerous and the supply of food at all scanty. Usually they are most abundant in dry pastures and the neighboring grain fields; this is due to the fact that their eggs are laid in grass lands, especially where the soil is dry and sandy, and the young nymphs grow there to maturity. They do not pass through any chrysalis stage, but gradually become bigger after each moult till the full-winged adult state is reached.^ ManjJ mechanical devices have been employed for their destruction, but the use of these troublesome methods can now be dispensed with since the discovery of the Criddle mixture, a poisoned bait which derives its name from Mr. Norman Criddle, of Aweme, Manitoba, who proved its complete efficiency after a series of experiments. It is made and applied as follows : Take a three-gallon patent pail and fill it with fresh horse droppings, then empty into a barrel; repeat this five times. As each pailful is poured in, mix thoroughly with the manure about a quarter of a pound of Paris green and half a pound of salt which has been dissolved in water. There would thus be used about one pound of Paris green and two pounds of salt to half a barrel of manure. The mixture may be drawn in a cart to the infested places and scattered broadcast with a trowel or wooden paddle. The grasshoppers are attracted to it from considerable dis- tances and are killed in large numbers. It has been found most effective to distribute the mixture on alternate days, a little at a time, rather than to use larger quantities at longer intervals. In the case of grain fields, oats being especially liable to attack, the mix- ture should be thrown into the grain along the sides of the field and the grasshoppers will eat it in preference to anything else. Care should be taken not to allow cattle or poultry to have access to it. Plant-Bugs. — In the American use of the word the name Bug is erroneously applied to insects of every kind — to a beautiful butterfly or moth as well as to a disgusting bed-bug. The name, however, when correctly employed denotes insects belonging to the order Hemiptera, which are provided with sucking and not biting mouth- Earts, and which do not pass through any quiescent chrysalis stage ut are gradually developed from the newly hatched larvae to the winged adult. To the true bugs belong two species which are very abundant in gardens, attacking plants of all descriptions, flowers and vegetables alike. These are the Tarnished and the Four-lined Plant-bugs. Tarnished Plant-bug. — This is to be found all through the sea- son on plants of almost every kind, sucking the juices of flower buds and foliage and sometimes of the leaves of young fruit trees. The mature insects are oblong in form with a triangular head and promi- nent eyes, and tapering to a rounded angle at the tail. The color is variable, usually grayish brown, marked with yellowish and black dashes, and having a slight bronzy reflection; its length is a little over a quarter of an inch. They are very active insects, taking 140 INSECTS AFFECTING VEGETATION flight readily when disturbed, or dodging round to the other side of the plant. Four-lined Plant-bug. — This is much the same size and shape as the preceding, but is yellow in color, with dark lines down the back and four black dashes along the thorax. Its attacks are most noticeable in early spring, when it may be found on mint, sage, cur- rant and gooseberry bushes, and often also on potatoes. It sucks the juices of the tender terminal leaves, causing them to shrivel up and turn back, and frequently severely injuring the plant. The stand- ard remedy for these and other sucking insects is spraying with strong kerosene emulsion; where this cannot be applied, as in the case of many flowering plants, dusting with pyrethrum insect pow- der has been found quite effective. Much may be done by knocking off the bugs with a stick into a pan containing a little water covered with a film of coal-oil; this should be performed in the cool of the morning when the insects are less lively than during the heat of the day. White Grubs. — These are the larvae of May-beetles or June- bugs which breed for the most part in old pastures. The beetles appear about the end of May or early in June and attack the tender foliage and buds of fruit and ornamental trees, often inflicting a considerable amount of damage. They come out at night and swarm about the trees, making a loud buzzing noise: many are at- tracted by lights in houses and cause some consternation among the inmates through their clumsy flight about the room and the noise that they produce ; as they can neither sting nor bite no alarm need be caused by their presence. During the night they feed and by morning all disappear, hiding underground where the soil is loose and under grass or rubbish about fences and buildings. At this period boys might be employed to search for and kill them ; trap- lanterns have sometimes been used with advantage, and spraying the trees they frequent with Paris green will destroy large numbers. The beetles deposit their eggs on the stems or roots of grasses just below the surface of the soil ; from these the grubs hatch out and feed for two or three years underground. During the summer of their third season thev change to the pupal state and transform to beetles about September, but do not come out until the following spring. This long larval stage accounts for the fact that in some localities the beetles only appear once in three years. The grubs, when fully grown, are thick, fat creatures, white in color — hence their name — with the body partially curled up and the last segments discolored from the food showing through the skin. When an old pasture is broken up they live for a time on the grass and roots that have been turned under and then attack whatever plant may be grown. The first and second crops usually suffer most, especially strawberries and corn ; clover is least affected by them and may be seeded down with rye, then small grains followed by corn or potatoes. Late and deep plowing will break up the winter quarters of the grubs and beetles and expose them to frost and also to the various animals that prey upon them. Pigs and poultry greedily EXTOMOLOGY 143 devour them ; crows and other birds and skunks also destroy large numbers when they can get access to them. In gardens digging deeply and trenching in the fall is very useful, but in the flower beds where perennials are grown this is im- practicable, and therefore recourse can only be made to disturbing the soil between the plants as much as possible in late autumn and early spring. Lawns and golf-links are frequently very badly af- fected as they are left for many years undisturbed; sometimes the roots of the turf have been so completely eaten off that the sod may be rolled up like a carpet. In such cases the best plan is to dig up the part affected and destroy the grubs, put in a fresh layer of soil and resod or sow with grass seed. For small patches, watering with kerosene emulsion, and washing it well in with plenty of water from the garden hose, will kill the grubs. Where large areas are found to be affected on golf-links or in pastures, the most effective plan is to enclose the place with hurdles and turn in a few young pigs; they will soon root out and devour all the grubs, and may then be re- moved to another spot. Wireworms are the larvae of Click-beetles, so called from their curious habit of springing up in the air with a click when laid upon their backs. The beetles are long and narrow, rounded above, with very short legs and usually dull gray or black in color. The grubs are long and cylindrical, with a very hard integument from which they get the name of Wire-worms, and yellow or whitish in color. The life history is very similar to that of the White-grubs; they breed chiefly in old pastures, take two or three years to mature, and feed upon the roots of any plants that may be convenient to them ; they are especially injurious to corn, and often may be found during the winter feeding inside potatoes in which they burrow great holes. No treatment of the soil with salt, poisons, etc., has any effect upon them ; the only remedy is a short rotation of crops as in the case of White-grubs ; plowing in August and cross-plowing again in Septem- ber will destroy large numbers of them. In gardens, as the beetles usually spend the winter under any shelter they can find, clean culti- vation, especially along the fences, is of great importance ; in spring many may be destroyed by placing bunches of clover or weeds pois- oned with Paris green under shingles or bits of board where the beetles go for shelter. ASPARAGUS. Asparagus Beetles. — The two species, the Blue and the 12- spotted, have spread over a great part of Ontario during the last few years and in many places are very abundant. Both species are often to be found upon the same plant; the former is shining blue-black in color with creamy-white blotches on the wing covers which vary a good deal in size and shape, and sometimes form a cross of the ground color of the back ; the sides and the thorax are dull red and the head black. The other species is the same length, about a quar- ter of an inch, but is somewhat stouter; the whole insect is dull red and polished and has twelve round black spots on the wing covers. 144 INSECTS AFFECTING VEGETATION Both these beetles pass the winter in the adult stage and are ready to attack the asparagus shoots as soon as they appear above ground in the spring; these they gnaw and spoil for table use, and the Blue species deposits upon them its shiny black eggs which are attached by the tip to the plants. Later on the eggs of both species may be found upon the growing plants, and the larvae soon appear. Those of the Blue beetle are dark olive gray grubs, which feed openly upon the foliage ; the grubs of the 12-spotted are yellowish or somewhat orange in color, feeding at first upon the tender foliage, but boring into and devouring the pulp of the seed capsules as soon as they are large enough to attack. The life cycle of both kinds re- quires only six or seven weeks for its completion and we therefore find all through the season till sharp frosts come in the autumn, eggs, larvse and beetles in great numbers at the same time ; the pupal stage is passed beneath the surface of the ground. The simplest and most efficient remedy is to let poultry have the run of the beds ; they will devour both beetles and grubs and will not touch the asparagus. Where this is not practicable, the young shoots should be dusted with fresh air-slaked lime when the morning dew is on the plants; this, of course, should be washed off before cooking. At the same time some of the shoots may be allowed to grow and attract the beetles which may then be killed with Paris green or arsenate of lead. If the plants have many eggs upon them, they should be cut off and burnt and others left to grow in their place. After the cutting season is over the plants should from time to time be sprayed with one of the arsenical poisons, but when the seed capsules are formed this will be of no avail against the grubs of the 12-spotted species. To get rid of it, the seed bearing plants should be cut off and burnt. In early autumn it will be well to cut down and burn the whole of the plants. The Asparagus Miner. — The stalks of asparagus are fre- quently attacked by insects, and in recent years have been reported considerably injured by the larva or maggot of a minute black fly to which the name asparagus miner has been given. The larva mines beneath the epidermis of the stalk, and when it has transformed to the puparium or "flaxseed" stage the thin outer skin becomes more or less ruptured and the presence of the insect is easily detected. It operates more abundantly near the base of the stalks and penetrates below the surface of the ground to a depth of 7 or 8 inches. The larva is about one-fifth of an inch long and milk-white in color. Like other maggots, it is footless, large at the posterior ex- tremity, and tapering toward the head. The puparium is not unlike the flaxseed of the pernicious Hes- sian fly, with which it has been aptly compared. At a little dis- tance, also, it suggests a Lecanium scale. This stage is remarkable because of its peculiar flattened and curved position, as seen from the side. It is red in color, and measures about 3.5 mm. in length and about 1 mm, in width, The egg has not been observed. ENTOMOLOGY 145 In its injurious occurrences this species appears to be limited to the eastern United States, from New England to Tennessee. With our present knowledge of the life economy of this species, two methods of control suggest themselves as of greatest value, and it may be that they will prove all that is necessary under ordinary conditions. (1) In spring permit a few volunteer asparagus plants to grow as a trap crop, to lure the fly from the main crop or the cutting beds for the deposition of her eggs. After this has been accom- plished the trap crop should be destroyed by pulling the infested plants and burning them with their contained puparia. The time to pull the plants will vary according to locality and somewhat ac- cording to season also. The second and third week in June would be about the right time in and near the District of Columbia. On Long Island this work should be done a week or two later. In the northernmost range of this insect — for example, in Massachusetts — the last week of June would be a suitable time. These plants must be destroyed before the end of the cutting season, otherwise they are apt to provide abundant rust infection. (2) The second generation can be destroyed in like manner by pulling old infested asparagus stalks as soon as attack becomes manifest and promptly burning them also. If this work were care- fully done over a considerable area, it would leave little necessity for other methods, since it would do away with these insects in the vicinity and leave few to be dealt with another season; unless, in- deed, this insect has an alternate food plant. Thoroughness and the co-operation of neighboring asparagus growers are essential for suc- cess.—(Cir. 135, U. S. D. A. B. E.) BEANS. The Bean Weevil. — It is a very small beetle, one-tenth of an inch long, only half the size of the Pea-weevil, which in other re- spects it closely resembles. It is grayish brown in color, due to a coating of dense fine hair; the wing-covers are marked with a series of lines running lengthwise and have a mottled appearance. The beetle is oval in shape, the head is bent down and terminates in a short square beak; the end of the abdomen is not covered by the wdngs, and differs from that of the Pea-weevil in being destitute of the two oval black spots which are characteristic of the latter. The eggs of the insect are laid upon the young bean pods ; the grubs, as soon as they are hatched, bore through and enter the beans inside, several making their way into a single bean. Maturity is reached in the autumn, when the beetles emerge if the season is warm; otherwise they remain all winter in the ripened bean. If unmolested they will increase and multiply in the dry seeds and continue their work of destruction for a long time. It is therefore useless to hold over the seed for a year, as may be done to get rid of the Pea-weevil. Whenever this insect is found to be present, the beans should be fumigated as soon as practicable after they are harvested. This is done by putting them in a barrel or tight bin and pouring on 146 INSECTS AFFECTING VEGETATION them one ounce of bisulphide of carbon for every 100 pounds, and then closing the receptacle tightly and leaving it for 48 hours. At the end of this time every insect will be dead. As the fumes of this substance are inflammable and explosive, it should not be used near any light or fire. Beans that have been injured by the insect should on no account be used as seed, as most of them will fail to germinate, or at any rate will produce only feeble plants. The Bean Plant-Louse. — Windsor or Broad Beans and Horse- beans are not much grown in this country, though in some places they are found of value as an addition to ensilage. Some difficulty is experienced in obtaining satisfactory crops owing to their liability to attack by this black Aphis, which is a serious pest in Europe. At the time of flowering the colonies of this insect are to be found cover- ing the tips of the plants so thickly that they look as if dusted with soot; if let alone the}'' soon multiply enormously and greatly reduce the vitality of the plants. The most successful plan is to cut off the tips of the affected plants and destroy the colonies of Aphis by burning or trampling under foot. This has the additional benefit of checking the growth and causing the pods to fully develop. Spraying with kerosene emulsion or strong soap-suds will also be effective. Other Insects. — Beans, like other vegetables, are liable to be in- jured by Cutworms when the plants are small, and later on in the season by the Tarnished Plant-bug. Broad beans are also subject to attack by the Black Blister-beetle, which is one of the enemies of the potato plant, and sometimes appears in destructive numbers. The Bean Leaf-Roller. — The bean leaf-roller is quite destruc- tive to beans. The larvae feed upon the leaves, eating holes in them or eating along the edges. Leaflets are folded over, to form a retreat. The larva is about one and one-fifth inches in length, fusiform in shape, the body being thickest in the middle, with small neck and large head. The general color is yellowish, with a dorsal black strip, and two lateral orange stripes extending down the body. The insect can be successfully treated. Use Paris green, in the proportion of one pound to 150 gallons of water, add to this one pound of quicklime, first made into a thin paste, to destroy the burning effects of Paris green on the foliage, or arsenate of lead 2 lbs. to 50 gallons of water. Apply with spray pump, keeping mix- ture well stirred. — (Bui. 45 Fla. Agr. Exp. Sta.) BEETS AND SPINACH. Blister Beetles. — Beets and spinach are liable to be attacked by many of the common garden pests that are general feeders, such as Cutworms which bite off the young plants close to the surface of the ground, Wire-worms and White-grubs which feed upon the roots, Flea-beetles, Leaf-hoppers, the Tarnished Plant-bug and Grasshop- pers which affect the foliage. Descriptions of these insects and the methods of dealing with them will be found elsewhere. Mention may be made of a few other insects which occasionally attack these plants in injurious numbers. ENTOMOLOGY 147 Blister Beetles are long, narrow, soft-bodied insects which be- long to the same family and possess the same blistering qualities as the Spanish-fly, which is used by druggists in the preparation of certain plasters. There are three species which may be distinguished by their color; the Black, the Gray and the Spotted; a fourth, the Striped, is occasionally to be found. Of these the Black is the most common and may often be seen feeding harmlessly on the flowers of the Golden-rod. At times these beetles appear in swarms and rapidly devour the foliage of beets, potatoes and a few other plants, and after inflicting a considerable amount of damage suddenly dis- appear. They may be controlled by spraying with Paris green, but this should not be resorted to unless the attack is serious, as their grubs have the very useful habit of feeding upon the eggs of grass- hoppers and may therefore be included amongst the beneficent in- sects. A better remedy, which has been employed with success, con- sists in driving the beetles away from an infested field by a party of men or boys walking in a line across and waving branches from side to side. The beetles thus disturbed fly ahead, and by following them up may be cleared out entirely ; once they are driven out of a field they seldom return. Spraying with Bordeaux mixture will keep them off the plants, and may be employed if necessary. The Beet Leaf -Miner. — Blotches may often be seen on the leaves of beets and spinach, which are found on investigation to be caused by a minute maggot which feeds on the green tissue below the skin. The parent insect is a two-winged fly about a quarter of an inch in length, which deposits its eggs on the foliage of these plants ; the maggots when hatched immediately burrow beneath the surface and cannot therefore be reached by any applications. The only method that seems at all available is to pick off and destroy the infested leaves, a laborious plan which can only be adopted where the plants are grown on a small scale. If the attack is serious it would be worth while to adopt this method in order to get rid of the trouble and guard against its repetition. Caterpillars. — The foliage of beets and spinach is liable to be attacked by some caterpillars, but as a rule they are in small num- bers, widely scattered over the plants and seldom inflict much damage. This does not apply to the extraordinary outbreaks on rare occasions of the Army-worm and the Variegated Cutworm, which devour every green thing that they come to, beets as well as everything else. Among the others referred to may be mentioned the Yellow Woolly-Bear, which is a hairy caterpillar, readily seen from its bright yellow color, and attaining to an inch and a quarter in length when fully grown. It turns into a beautiful snow-white moth, with a few black dots on its wings and rows of black and yellow spots on its body. When feeding they are conspicuous, and may be picked off by hand ; but usually they are beneath the leaves when at rest. If very numerous, Paris Green may be employed. They are general feeders and do not confine themselves by any means to garden vegetables, but attack many kinds of weeds as well. 148 INSECTS AFFECTING VEGETATION Leaf-Hoppers. — A number of species of leaf-hoppers feed oil the leaves of the beet. All are small, rather slender, and all jump on the slightest provocation. They suck the sap from beneath the surface of the leaves, leaving a small dead spot to mark each punc- ture. This would ordinarily amount to little, but when the insects come in swarms, as is often the case, the aggregate amounts to a good deal. It is not possible to control these pests by spraying with poisons, as they pierce beneath the surface for their food supply. The contact insecticides will kill a certain proportion of them, but no spray yet devised is satisfactory unless used when the pests are small. They pass the winter in rubbish, under leaves, etc., there- fore collect and burn all rubbish after cold weather sets in. Grasshoppers. — When, from time to time, grasshoppers attack the beets, they should be killed by poisoned baits, provided of course, that such baits may be used without danger to stock or poultry. Criddle mixture, a mixture of arsenic, salt and horse- manure, is highly recommended by several Avho have tried it. Bran and arsenic, or paris green and bran, has the disadvantage that it is readily eaten by birds and poultry. For a further discussion of grasshoppers see Insects of Sweet-corn. Beet Web-Worm. — From time to time we meet the beet web- worm, an insect that, on several occasions, has been very severe in its attacks. The eggs of the web-worm are laid on the leaves, and the larvae that come from them attack the foliage, either spinning small webs among the young and tender shoots at the center of the plant, or else feeding on the underside of the larger leaves, either protected by a small web of silk or else exposed, with no protection whatever. The caterpillars are pale yellowish-green, or reddish- yellow in color dotted with small black points, each of which bears a hair. They are about three-fourths of an inch in length. The head is yellowish-brown marked with brown spots; the prothoracic shield is somewhat lighter in color. The backs of the first two segments each bear four black dots; segments three to eight each bear six black dots, arranged in two triangles. Segment nine has one larger median spot with two smaller lateral ones and segment ten has the anal shield, dirty yellow in color, marked with brown spots. The under side is marked somewhat similarly with dirty spots, each spot being bordered indistinctly with pale. The legs are pale with darker markings. The pupa of this moth is buried in the soil. The larva spins a slender silken tube about three-quarters of an inch long, and in this tube the pupal stage is passed. In the early broods the pupal stage is of short duration, but the members of the last brood remain in the tubes over winter. There are several generations each year. Spray with paris green on the first appearance of the larvae, using lime as indicated in the directions for preparing insecticides. Use one pound of the poison to one hundred and seventy-five gal- lons of water. Plow the field after harvesting the beets, so as to ex- pose the pupae to the birds. In spraying, use a nozzle set at right ENTOMOLOGY 149 angles to a short extension, so that it will be easy to spray upward from beneath. CABBAGE AND CAULIFLOWER. These plants are subject to a series of attacks by insects from their first appearance above ground to maturity. Cutworms destroy a great many seedlings and young plants when they are set out in the spring. Later on Plant-lice make their appearance, and cover the leaves with their colonies, sucking out the sap and causing the foliage to dry up and wither; they become excessively numerous towards the close of the season, and in addition to the injury they inflict, cause the plants to present a disgusting appearance. Through- out the summer the leaves are liable to be devoured by several cater- pillars and in August and September by Grasshoppers, while the roots are frequently caused to rot by the Maggots of a small fly. Aphids and Cutworms and other general feeders are treated else- where ; reference will therefore be only made here to such insects as are peculiar to the Cabbage and other Cruciferous plants. White Cabbage Butterfly. — This insect, which came to us from Europe about fifty years ago, is now one of our commonest butter- flies, and may be seen flitting about everywhere from early spring till cold weather sets in. It is one of the worst pests that the- cabbage grower has to contend with unless measures are taken to prevent its ravages, and happily this is a matter of no great difficulty. The butterfly lays her eggs on the leaves of the food-plant; the cater- pillars are velvety green and almost exactly the color of the leaves upon which they are feeding; when at rest they lie at length upon the midrib and are not easily seen. There are two broods in the year, the later being much the more numerous, and sometimes a third if the autumn should be fine and warm. The caterpillars riddle the outer leaves and then burrow into the heads, devouring the substance and spoiling the plant for table use by their excre- ment. Besides Cabbages and Cauliflowers they attack also mignon- ette, stocks and nasturtiums. Pyrethrum insect powder is thoroughly effective. One pound should be mixed with four pounds of cheap flour and kept in an air-tight jar or canister for twenty-four hours so that the poison may be thoroughly incorporated with the flour. The plants infested by the caterpillars should then be dusted with the mixture which can be applied with a small bellows, or in a cheese-cloth bag tapped lightly with a slender rod. This powder will kill insects, but is per- fectly harmless to human beings. Another method, which is more rapid in its effects upon the worms, is to dissolve two ounces of the Pyrethrum powder in three gallons of lukewarm water and spray at once. The liquid kills immediately all the caterpillars it reaches, while the dry powder often takes many hours to produce the same result. Paris green and other virulent poisons should never be ap- plied to Cabbages and vegetables of any kind that are intended for table use. Zebra Caterjullar. — There may often be found feeding upon Cabbage and some other garden plants of the same family, a hand- 150 INSECTS AFFECTING VEGETATION some caterpillar about two inches long, when fully grown. It is vel- vety black on the back and has two bright yellow stripes along the sides, which are connected by a series of irregular yellow lines on a black ground-color ; the head and feet are reddish. These strikingly contrasting colors render the caterpillar a conspicuous object on the green foliage that it feeds upon, and make it an easy task to pick them off by hand. There are two broods in the year, the moths, which are dull reddish-brown with white underwings, appearing in May and August. The young caterpillars when first hatched feed in colonies and devour the green substance of the leaves, thus pro- ducing white blotches on the foliage and rendering their presence easily noticeable. Should they be too numerous to be destroyed by hand picking, resort may be had to Pyrethrum powder applied as mentioned above, or to white hellebore which may be dusted on the leaves or sprinkled by mixing one ounce in two gallons of warm water, stirring from time to time to prevent the powder from settling at the bottom of the watering can. Cabbage Plusia. — A pale green caterpillar, with whitish lines running lengthwise of the body, may sometimes be found devouring the leaves of cabbages, lettuce and other vegetables, feeding usually on the under side of the foliage. It is called a semi-looper from its raising the middle of the body when walking, owing to the absence of some of the usual prolegs. In the early part *of the season they may be got rid of by dusting with a mixture of one pound of Paris green in twenty pounds of lime, applying the powder to the under side of the leaves. A liquid spray may also be used of the ordinary composition. Diamond-Back Moth. — This is from time to time a serious pest, as its caterpillars appear in large numbers and devour the foliage of cabbages, turnips and other cruciferous plants. These worms are much smaller than those of the preceding species ; are green in color and remarkably active when disturbed; they will then wriggle about in a violent manner and drop to the ground by a silken thread from the leaf on which they are feeding. As they devour all the green substance of the foliage the plant attacked soon withers and dies. There are usually two broods in the year, the first set of caterpillars appearing at the beginning of July, and the second towards the end of the summer; in favorable seasons there may even be a third. The winter is spent in the pupal stage, the lace-like cocoon enclosing the chrysalis being attached to the under side of the leaves. The moth is a beautiful little creature, dark or ashen gray in color, with a series of white marks on the forewings which form, when the wings are closed, a row of diamond-shaped markings down the middle of the back; from this characteristic the moth receives its name. The remedy that seems most effective is spraying the under- side of the leaves wherever attacked with kerosene emulsion, at the same time applying fertilizers, such as nitrate of soda, to induce a vigorous growth. As a preventive measure all remains of stalks and foliage, after the crop has been taken in, should be destroyed in order to get rid of the wintering chrysalis. Though the insect is an ENTOMOLOGY 151 importation from Europe, it is largely kept in check by parasites and only occasionally becomes a serious pest. Cabbage Maggot. — This is one of the most serious insects that growers of this vegetable have to contend with. Young plants, soon after being set out in the spring, are often found to have their roots infested with these maggots, their presence being indicated by the dying of the plants. They are white, footless larvaa, the offspring of slender two-winged flies, smaller than the ordinary house fly; the eggs are laid on the stems of the plants close to or just beneath the surface of the ground ; when hatched, the maggots burrow down into the roots, where they tear the tissue with the hooks which take the place of their jaws, and live upon the sap; the breaking up of the cells of the plant causes a rot to set in and the entire destruction of the root soon follows. When full grown the maggots form their reddish brown puparia in the soil near by, and from these a second brood of flies soon emerges. Working under ground as they do, it is a difficult matter to apply any effective remedy ; the only one that has proved useful is a decoction of pyrethrum insect powder (quarter of a pound to a gallon of water) or white hellebore of the same strength. The earth is drawn away from the root of an af- fected plant and half a tea-cupful is poured in ; the soil is then re- placed and hilled up around the stem. Preventive measures are less troublesome and usually more effective. One of the best is the screening of newly set-out cabbages and cauliflowers with cheese-cloth. Light frames of slats are made 8 feet long, 2 wide and 2 high ; over these is tacked cheese-cloth which should reach to the ground on all sides, and be prevented from blow- ing about by heaping a little earth on all edges. These frames cost very little and can be readily moved when required and stowed away for future use ; they should be put on as soon as the plants are set out and left till they are well-grown. The frames not only pre- vent the flies from laying their eggs on the plants, but also keep off the other insects which are liable to attack them. Tarred paper disks, three inches in diameter, with a slit from one side to the middle, are used to place around the stems of plants when they are set out, and prevent the flies from laying their eggs upon them. These are somewhat troublesome to make and put on and are not nearly so effective as the cheese-cloth screens. Cabbage Aphis. — From mid-summer until fall, cabbages are subject to attack by plant lice. Of course the lice are present earlier in the season but in such small numbers that they escape detection. Both winged and wingless forms occur, all of them being covered with a coat of fine waxy powder, very much like the bloom on the leaves of the cabbage on which they rest. This waxy bloom, no doubt serves as a protection by helping to conceal the insect, but when we come to spray we find that it helps very effectually to repel the liquid. Lying, as they do, in closely packed colonies, which sometimes cover almost the entire underside of a leaf, one would expect to kill them with ease. One finds, however, on trying to do so, that most spray mixtures slide from them like water from a 152 INSECTS AFFECTING VEGETATION duck's back. Furthermore, it is very difficult to reach them when under the foliage. In order to overcome this last difficulty, we have used a short extension, about three and one-half feet long, with a Vermorel nozzle set at right angles to the extension. This makes it easy to reach the underside of the leaves and by simply turning the extension in the hand, one can spray downward on the head of the cabbage. The best sprays for the lice that we have been able to find are tak-a-nap soap, used at the rate of one pound to four gallons of water, and Pyrethro-kerosene-emulsion made with whale-oil soap. This is diluted ten times. Both of these sprays killed apparently all the lice that were hit. The difficulty of hitting all the lice with a spray can be appreciated only by those who have made the at- tempt.—(Bui. 233, Mich. Agr/Exp. Sta.) The Harlequin Cabbage-Bug * — The insects thus far mentioned as attacking cabbage do their injury by devouring the leaves. This one feeds in an entirely different manner, being provided with a beak with which it punctures and abstracts the sap. The effect of the puncture appears to be somewhat like that of the tarnished plant-bug. The leaves wither and turn brown as if scalded. It is very destructive at times, killing in this way the greater part of the plants in a field. It is a glossy, flatfish insect, about % inch long and nearly */£ inch in greatest width. The general color is black, and the mark- ings are of an orange, or reddish yellow. The wings are ample, and ordinarily lie flat on the back, with the plain black tips overlapping. The young differ chiefly in lacking the wings. They feed at all times after hatching from the egg. The calico-back, as it is sometimes called, places its relatively large eggs in two rows, side by side, on the leaves. They are some- what barrel-shaped, each with a dark band about the upper end, and a faint line and dot near the attached extremity. These marks vary a great deal however, and may be wanting, while often ex- tensive blotches appear. When the young hatch they push up a round lid-like piece at the free end of the egg. — (Bui. 114, Ky. Agr. Exp. Sta.) The adult spends the winter among rubbish in gardens and fields, and comes out very early in the spring to feed on the first plants of the cabbage family to appear. Several broods develop dur- ing the season. Within the cabbage family, it seems to have no preferences. Among other plants, it is known to feed on peas, grapes, and even corn, at times. Coal oil in emulsion is about the only thing that can be recom- mended for such insects, since it is necessary to kill them by means of a contact insecticide, except the use of the gasoline torch. Owing to the disposition of the insect to hide among the leaves where it cannot readily be reached with sprays, it is not easy to get rid of. One of the best remedies is the sowing of some trap crop before the regular sowing, then when the bugs have been drawn to it, plants and bugs can be destroyed with hot water, oil, or fire. *See page 411, for illustration ENTOMOLOGY 153 It is not consistently present in our fields. Some seasons it appears in scattered localities and occasions a good deal of complaint. Then it disappears and nothing is heard of it for a number of years. It seems not to endure very severe winter weather, being a southern insect, and this mav account for its comings and gomes. — (Bui 114, Ky. Agr. Exp. Sta.) * V Black Swallow-Tail Butterfly. — There may often be found feed- ing on the foliage of carrots and parsnips a handsome velvety green caterpillar ornamented with bands of yellow. This is the larva of one of our largest and most beautiful butterflies, black in color, or- namented with rows of bright yellow spots. The caterpillars do not feed, in colonies and consequently are not often injurious, the amount of foliage consumed by an individual seldom affecting the vitality of a plant. Being conspicuous, they may, if sufficiently numerous to require repression, be picked off by hand and crushed under foot. They are kept in check, however, by a large parasitic fly, which lays an egg on a caterpillar from which hatches out a grub that feeds within the body of its host until the chrysalis is formed, and then completes its work of devouring all that remains, a fly with four clear membranous wings coming out instead of the butterfly. Carrot Rust-Fly. — This is a more serious enemy to the plant than the preceding species. It is a comparatively recent importation from Europe, having been first observed in this country about twen- ty-five years ago. Its attack may first be noticed in spring when the leaves of young carrots turn reddish, and on examination the roots will be found covered with rusty blotches, hence the name of the in- sect. The parent of the mischief is a small two-winged fly, one- quarter of an inch long, with dark green body, head and legs pale yellow and the eyes red. From the eggs, which are laid on the stem below the surface of the ground, the young maggots make their way into the root, and tear the tissues in a similar manner to the cabbage maggot described above ; the attack causes the rusty blotches to appear. The maggots of a later brood infest the full-grown roots and continue their work of destruction in the root-house during the winter. Celery and parsnips are also attacked. Preventive measures seem to be the only remedies available. To deter the fly from laying her eggs, the rows of young carrots, ^vhen ready for thinning out, should be* sprayed with kerosene emul- sion, or dusted with sand or plaster in which coal-oil is mixed, half a pint being-used to a pailful of the material. The application should be made weekly, and especially after hoeing, until about the middle of July. In gardens where carrots are grown for table use and size is not an object, late sowing is found to be advantageous, the plants thus escaping the egg-laying of the fly. Repeated sowings a week or so apart, will secure the freedom of some of the crops from attack. The plants should not be grown two years running in the same piece of ground. Stored roots, if found affected in the winter, may be treated 154 INSECTS AFFECTING VEGETATION with carbon bisulphide, one ounce to 100 lbs. of roots, placed in pans on top of the pile, provided that they are in fairly air-tight bins. They should be left for 48 hours and then exposed to the air in order to get rid of the fumes, which are very inflammable ; no light or fire should be anywhere near when this substance is being em- ployed. CELERY. Celery, as a rule, is not much affected by injurious insects; those that do attack it are the same as the enemies of carrots and parsnips, to which reference is elsewhere made. The handsome caterpillars of the Black Swallow-tail Butterfly may often be found eating the foliage, but they are never very numerous and can easily be controlled by handpicking. A small caterpillar called the Celery Leaf-Tyer is sometimes abundant and injurious; it feeds for the most part at night; when young it eats small holes in the leaves which are hardly noticeable, but as it grows larger it becomes more voracious and consumes a considerable amount of foliage. When fully grown they roll up a leaf and tie its edges together with silk, forming thus a convenient case in which to pass the chrysalis stage. The moth is about three-fourths of an inch in expanse of wings, pale brown in color, with a reddish suffusion ; the wings are marked with irregular cross lines of black and some circular spots. There are at least two broods in the year. The insect is sometimes known as the Greenhouse Leaf-tyer from its attacking a variety of hot-house plants ; out-of-doors it by no means confines itself to celery, but may be found on a great variety of vegetables. As soon as the cater- pillars are noticed the plants attacked should be sprayed with Paris green, applied to the under side of the leaves. In the greenhouse any infested leaves should be cut off and destroyed. One of the most serious enemies of celery is the Rust-fly de- scribed among the insects affecting carrots. The maggots attack the thick part of the roots of young celery plants and prevent their proper growth; they also produce the characteristic rusty blotches on the stems and spoil them for table use. Celery Aphis. — Occasionally celery is infested by one of the plant-lice or green-flies. The writer has never seen any serious in- jury by these insects, but in case they become troublesome, kerosene- emulsion should prove effective as should also tobacco water. Little Negro-Bug. — This insect ordinarily seems to prefer weeds to celery, but on occasion, it has been known to overspread a celery field in late July, collecting in little clusters on the leaves, and playing sad havoc with the commercial fields. The outer leaves of the stalk suffer first, but later the inner, feathery ones that go to make the market head. The cause of all this trouble is a small, shining black bug, very convex and quite broad comparatively, the length being a little less than one-eighth of an inch. The insect is said to rear only one gen- eration each year. It is known to work on strawberry, raspberry, grape, wheat, some grasses, and a number of weeds, including red- root and ground-nut, beggar-tick, plantain, rag-weed and smart weed. ENTOMOLOGY 155 Mr. Davis recommends crude carbolic acid and water used at the rate of a teaspoonful to two gallons of water and sprinkled over the plants or else crude carbolic and air-slaked lime used at the rate of a teaspoonful of the acid to a bushel of lime, and dusted over the plants. The emulsion of carbolic acid diluted so that the same amount of the acid is found in two gallons of water, will make a more even preparation and one would expect less danger from burn- ing the plants than with the plain mixture. The experimenter has never had an opportunity to try this, however. Mr. Davis found that hot water killed the bugs when used at 155 degrees Fall, and that the plants were killed at 175 degrees. On a small scale, this can be applied with a sprinkler if care be taken to test the water with a thermometer carefully and at short intervals. The long list of weeds which serve as food-plants for this little nuisance, shows plainly that the removal of weeds from the vicinity of the celery fields will be the most effective preventive measure at our command. Clean culture is, after all, a measure which pays well. CUCUMBER AND MELON. Cucumber Beetles — the Striped and the Spotted. — The former of these insects may be found all through the season on cucumbers, melons, squashes and pumpkins from the time that the plants are first set out till the frost destroys the foliage in the autumn. The beetles hibernate in the adult stage and are ready to attack the seed- ling plants as soon as they appear above the soil ; oftentimes they are sufficiently numerous to kill the tender plant by eating the leaves and gnawing the stem; later on they may be found in the flowers, where, however, they seem to feed on the nectar and not to do much harm. The beetle is less than half an inch in length, oval in shape, yellow in color, with a black head and three black stripes down the back. The larvse are slender white grubs which feed upon the roots of the plants and sometimes burrow up into the stem, continuing their injuries for about a month, when they change to the pupal stage and later on come out as a second brood of the beetles. The latter are very lively insects, flying quickly from plant to plant when disturbed; sometimes when their usual food is not available they at- tack the young pods of peas and beans, and may be found on a va- riety of other plants. The Spotted Cucumber beetle is larger than the Striped, and less oval, broadening considerably towards the posterior end of the body ; its color is yellowish green, with a black head and three rows of four black spots, making twelve in all, on the wing covers. It is a more southern insect than the Striped beetle, and in many parts of the United States it does serious injury to the roots of corn. It is a much more general feeder, attacking a great variety of plants; its life history is somewhat similar to the preceding, but it seems to feed mostly upon the pollen of blossoms in the beetle stage, the grubs being the chief cause of injury by their attacks upon roots and stems. The treatment for both insects is chiefly preventive. Young cucumber and melon plants should be protected as soon as they are 156 INSECTS AFFECTING VEGETATION set out with the cheese-cloth screens described as a protection against the Flea-beetles, or by smaller screens made with two flexible sticks crossed at right angles and with their ends securely fixed in the ground, and then covered with a piece of cheese-cloth, which can be kept from being blown about by heaping a little earth on the edges. These screens may be safely removed when the plants have grown too big to be covered by them. Another plan is to grow a few squash plants earlier than the others so as to attract the beetles to them, and then treat them with Paris green, one pound mixed with 50 lbs. of lime or plaster; this may be dusted over the plant when the beetles congregate upon it. In the autumn all the refuse of the vines should be gathered up and either burned or buried in a compost heap, so as to kill the hibernating beetles. Spraying the young plants with poi- soned Bordeaux mixture has also been found effective. The Squash-Bug. — The bugs are much larger insects than the beetles described above, being nearly three-quarters of an inch in length, of a dirty blackish color above and speckled creamy beneath ; they have the usual repulsive odor common to the stink-bugs, to which family they belong. Late in autumn the bugs may be found in all sorts of places, crawling about in search of winter quarters, and should then be crushed under foot. In the spring they come out, and begin their injurious work of sucking out the juices of young cucurbitaceous plants. The eggs, which are metallic in color, are laid in batches on the under side of leaves near the base of the plant; from them soon hatch out the young bugs, but not all at once, so that we may find nymphs of all sizes on the under side of the same leaf. They not only injure the foliage by sucking out its juices, but also poison it as well, causing a speedy wilting of the leaves they at- tack. If any withering leaves are observed they should at once be inspected, and if a colony is found at work it can soon be extermin- ated by crushing under foot. These bugs are difficult to get rid of, as the usual remedies for sucking insects, kerosene emulsion, for instance, have but little effect upon them, except when applied to the colonies of young nymphs. The methods recommended above for Cucumber beetles are also the best remedies for these disagreeable insects. In the early part of the season the parent bugs may be trapped by laying pieces of shingle or board near the plants; the bugs will be found taking shelter under them in the morning and can easily be destroyed. Flea Beetles, described above, are often very injurious to young cucumber and melon plants, and also a species of Aphis. Occasion- ally the fruit is attacked when green by small caterpillars, one called the Pickle-worm, and another the Melon caterpillar; both turn into beautiful little moths. In the South they are regularly injurious year after year. Should they become numerous at any time they could be easily controlled by the use of arsenical poisons. The Fickle Worm. — Injurious to the fruit of cantaloupe, squash, cucumber, and other cucurbits. Holes are eaten into the rind or quite to the interior, causing the decay of the fruit- The insect ap- ENTOMOLOGY 157 pears after the middle of June, and early crops hence escape their ravages. Eggs are probably deposited, as a rule, on the fruit, blossoms or foliage, and the young larvae soon begin to feed. The life cycle re- quires about twenty-seven days, and several broods occur each season. The winter is past in the pupa state in the dead cucurbit leaves, and trash in and around the field. About seven months of the life of the insect seems to be passed in the pupa state. The most hopeful method of protecting cantaloupes from this insect, that we have discovered, is in the use of squash plants as a trap crop. A decided preference seems to be shown for the bloom, vines and fruit of squash, which should be planted in and around canta- loupe fields, and the larvae carefully collected and destroyed. Arsen- ites and repellants have not thus far proven to be effective. Melon-Louse on Cucumber. — At all times after cucumbers com- mence to "run" they are subject to attack by a plant-louse. The in- sect is blackish-green in color and both winged and wingless forms occur. They multiply so rapidly as almost to cover the under sides of the leaves in a short time. Ordinarily in large fields, the attack commences in certain small, well-defined areas, from which the trouble spreads rapidly in ever widening circles rendered conspic- uous by the curled and discolored leaves. The source of the pests was for some time a mystery, but Mr. Theodore Pergande, of our Na- tional Bureau of Entomology, throws a great deal of light on the sub- ject when he explains that the same insect feeds also on cotton, orange, melons, strawberry as well as on a long list of our common weeds. In the light of this information, it is easy to see how the pest is kept alive until opportunity to attack melons and cucumbers offers itself. The fact that the pests work almost entirely on the undersides of the leaves, where it is difficult to apply sprays, makes them very serious pests to combat. The writer has made an effort to select a spray that will kill the greatest number of those hit, trusting to the operator to hit as many as possible and to repeat the application when necessary. Others have found it practical to place a low tent over the plants, and to fumigate with burning tobacco stems and other agents. Such fumigation has given partial success, but seemingly is little, if at all, superior to the sprays. The cost of fumigation is unquestionably greater. The spray that gave the best results with us was whale-oil soap kerosene-emulsion, with Pyrethrum added. (See directions for preparing insecticides.) This was diluted ten times. We succeeded in killing about 99 per cent of the lice, in one trial, doubtless all that were hit. In order to apply this spray with sufficient thoroughness, a knap-sack pump was used. This was fitted with a short extension, about three feet long with a Vermorel nozzle set at right angles to the extension, making it easy to apply the spray sidewise and upward from beneath. As stated, the lice usually start from one or two vines in a field. Careful watching will reveal these centers of infestation and prompt treatment should check their spread in the beginning. Of course it 158 INSECTS AFFECTING VEGETATION will be necessary to repeat the spray as often as the lice appear. As in the case of the lice on cherry, the difficulty lies in reaching the lice and not in making a spray that will prove effective. — (Bui. 45, Ga. Agr. Exp. Sta.; Bui. 233, Mich. Agr. Exp. Sta.) INSECTS AFFECTING THE HOP. Hop Merchant. — The spiny caterpillar of the hop-merchant is known to all hop growers. After a time, these caterpillars change to the naked pupae which are marked with golden or silver spots. From these pupae come the adults, very pretty butterflies of a general brown- ish color, marked with darker brown and slate. On the underside of each hind-wing is a silver mark, shaped like a comma, from which the insect takes its Latin name. The eggs are laid in strings on the leaves. Besides hops, the caterpillars feed on elm and nettle. The only remedies are hand picking and spraying with arsenical poisons early in the season. After the hops form, no sprays should be applied because of danger from poisoning. The Violet-Tip. — The violet-tip closely resembles the hop-mer- chant. It is, however, larger and the greys on the wings are apt to take on a more purplish tint. Each hind-wing is marked with a silver spot something like an interrogation mark. The larvae feed on nettle, elm and blackberry as well as on the hop. The treatment is the same as that for the hop-merchant. Hop-Louse. — Such a fragile creature as an aphid can hardly hope to pass the winter successfully on such a plant as the hop which is spread on the ground during the cold season. For this reason a curious habit has been developed. Late in the season, winged sexual forms are developed from the non-sexual form of the lice that have been feeding on the hop all summer, and these sexual forms lay their eggs on the plum trees, where the eggs are in good high situations, safe for the winter except from birds and other enemies. In the spring, wingless forms are produced at first, and from these, winged females which migrate to the hop to become the parents of the myr- iads of lice which later appear. The lesson to be learned from this life-history is very easy to see. Avoid having plum trees, either cultivated or wild, near the hop yards. If it is impossible to do this, then spray the plums with kerosene-emulsion, or tobacco-water just as soon as the eggs hatch, and spray with extreme care so as to hit as many of the lice as pos- sible, before they migrate to the hops. It will be necessary, in many cases, to spray the hops themselves, especially the vines on which the lice first appear, and which serve as centers of infection for the rest of the field.— (Bui. 233, Mich. Agr. Exp. Sta.) Onion Thrips. — Tiniest of all the insects mentioned in this paper, is the onion thrips. A little larger than a printed period and very active, it is so small and quick in its movements, that it is usually overlooked. The injury is brought about by the great num- bers that collect on the plants. On the onion, the thrips prefer the axillary portion of the plant, where two leaves join. They scrape the soft material off the leaves, giving them a grey or hoary High Power Spraying Outfit in Use in Treating Roadside Trees. Dept. of Agr. ENTOMOLOGY 161 appearance, sometimes noticeable at quite a distance. The leaves or tops decay if the weather turns wet and the keeping qualities of the bulbs are impaired. The immature insects are usually more abundant than the adults, they are about one-twenty-fourth of an inch in size, and yel- lowish-green in color. The body is long and slender, with six legs and six jointed antennae. The feet, like those of all true thrips are destitute of claws. The general color is dirty yellow with dusky markings. The antennae are seven-jointed in the adult. The ex- tremely narrow wings are fringed with long hairs giving them a feathery appearance. The time required for each generation is said to be about six days in the South. Here in Michigan, more time will, no doubt, be required; at any rate, a number of broods are developed each year. Thrips feed by scraping minute particles off from the soft parts of the plants, but as far as their control is concerned, they may be classed wTith the sucking insects, and we must resort to con- tact insecticides to kill them. Kerosene-emulsion, used at the rate of one part of the emulsion to ten of water will kill them. To- bacco water should also prove effective. Drenchings of cold water are said to be useful when practical, for thrips thrive best in a dry, warm atmosphere. — (B. 233, Mich. E. S.) ONION. Onion Maggot. — It is very similar in mode of attack and life- history to the Cabbage Maggot already described; it is unnecessary, therefore, to repeat these particulars. It is often extremely destruc- tive, and has almost driven market gardeners to despair. The pre- ventive measures referred to above are hardly suitable for a plant whose style of growth is so different from that of a cabbage, and few persons would take the trouble to protect onion beds with cheese- cloth screens, nor could tarred paper disks be employed. There is, however, a simple method of protection which has been found effec- tive: as scon as the tiny shoots of the onions begin to appear above the soil, the rows should be treated with a whitewash made of lime and water, and thick enough to form a thin crust over the surface. The effect of this is to close up all crevices and openings in which the parent fly would lay her eggs, and prevent the maggots which may hatch for any eggs laid above ground from reaching the roots beneath. The young plants penetrate through the thin crust of lime without difficulty. Later on, when hoeing, any plant that is not growing satisfac- torily should be cut out and crushed underfoot so as to destroy the maggots. Furthermore, onions should not be grown a second time on, or close to, a bed which has been infested with these insects. Pyrethrum insect powder or white hellebore may be applied in the same manner as recommended for the cabbage maggot. Many other substances, such as salt, plaster, Paris green, etc., have been tried without any satisfactory results. When taking up the onions in the fall any bulbs infested by maggots should be carefully destroyed. 162 INSECTS AFFECTING VEGETATION PARSNIP. Parsnip Webworm. — When parsnips are left in the ground all winter and allowed to grow up for seed-bearing purposes during the following season, they are very liable to be attacked by this insect. Towards the end of June, when the stems are tall and bear fine umbels of flowers, it is often found that the bloom is disfigured with webs which draw the whole into an untidy mass, and on exam- ination a colony of small caterpillars will be found at work within. When they have finished consuming the flower, they burrow into the stem and feed upon the soft inner lining; here they change to the chrysalis stage during the latter part of July, and are often so numerous that the hollow stems will be found packed with larvae or pupa?. The caterpillars are of a dirty green color above and yellow- ish on the sides and beneath ; most of the segments are furnished with shining black warts, each of which terminates in a fine bristle. The moths come out about the first of August and hibernate in any shelter that they can obtain, often coming into houses for the pur- pose; they are dusky gray in color, with no conspicuous markings, and with the body much flattened; the expanse of the wings is less than an inch, and the length of the body under half an inch. The insect is an European species. These caterpillars may be found in abundance working in a similar manner on celery plants that have grown up for seed and on wild carrot and other kindred umbelliferous plants. In the gar- den they should be treated with Paris green as soon as they are no- ticed ; if the umbels are drawn into a web, they should be cut off and burnt, and if the stalks are perforated the same operation should be performed on them. Wild carrots and parsnips should be cut down wherever they may be found in neighboring fields or waste places. Parsnips are also attacked by the insects already mentioned in connection with carrots and celery. PEAS. Pea-Weevil. — The life-history of this insect resembles in many respects that of the Bean-weevil, already described. The beetle is about one-fifth of an inch in length, brownish-gray in color, with two conspicuous oval black spots on the end of the abdomen which is not concealed by the wing-covers. The head is bent under the front of the body and ends in a square-cut beak. When peas are in blossom these little beetles may be found upon them, waiting for the young pod to be disclosed; on it the minute eggs are laid, and the grubs, as soon as hatched, bore through and enter the small green peas, one beetle only infesting a single pea. Here the grub remains, feeding upon the substance of the pea, passing through the pupal stage, and only attaining maturity when the peas are ripe and ready for harvesting. Most of the beetles remain inside the peas until they are sown the following spring, but some emerge when the peas become ripe, and remain in the field or in the barn all winter. Unlike the Bean-weevils, this species does not increase and multiply in the stored peas, but will die if they are kept over for another year. ENTOMOLOGY 163 The pea crops should be harvested early, a little on the green side, so that the pods will not shell out before removal from the field; threshing should be done as soon as possible, and all refuse. from the machine should be swept up and burnt. If any weevils are noticed in the peas, the crop should be put into bins or barrels and fumigated with carbon bisulphide in the manner recommended for the Bean-weevil. Peas that contain weevils, even though they are dead, should not be sown, as the plants grown from them will be stunted owing to the lack of food material in the pea; a consid- erable proportion would probably not grow at all, owing to the germ having been devoured by the beetle. The remains of the crop, not taken from the field, should be raked up and burnt. If every pea- grower would adopt these methods we should soon be rid of the pest as the beetle does not attack any other plant. Pea Moth. — The parent moth is small, less than half an inch in expanse of wings, and of a dull, slaty-gray color. It lays its eggs on the growing pods of peas; the caterpillars soon hatch out and bore their way into the pod, where they feed upon the young peas, consuming many of them and filling the space with a mass of excre- ment. When full grown the worms leave the pods and form their small oval cocoons below the surface of the ground. Where there is reason to expect an attack, the pea vines should be sprayed as soon as blossoming is over with a liquid wash of one pound of soap in twenty-five gallons of water in which has been thoroughly mixed four ounces of Paris green ; the spraying should be repeated a couple of times at intervals of a week or ten days. The object is to poison the young caterpillars when they are eating their way through the pod. Sowing early varieties as early as possible in the season has been found useful, the pods being too far advanced to be injured when the worms appear. Very late sowing is also recommended in order that the blossoming may not take place till after the moths have ceased egg-laying. An important point is to plow or dig deeply in the fall any piece of land where infested peas have been grown in order to bury the cocoons and prevent the moths coming out in the spring. All unripe pods should be burnt, as they may contain worms, and peas should not be grown again upon or near the same piece of ground the next season. Pea Aphis. — This large green plant-louse has during recent years become extremely destructive to the vines of peas. In some parts, where large acreages were devoted to this crop for canning purposes, the annual loss was estimated at many millions of dollars, three-fourths of the crop being in some instances destroyed. The usual remedies for plant-lice have already been referred to under "Aphis," but they are of little value when contending with an at- tack on a very large scale. A method that has been found effective is to sow the peas with drills and wide enough apart for a culti- vator to work between the rows, instead of the usual broadcast plan. As soon as the plant's are seen to be infested boys are employed to 164 INSECTS AFFECTING VEGETATION brush the insects off, and they are followed at once by the cultivator, which buries the lice and prevents their getting back on the vines. The operation has to be repeated a few times, but the results have proved entirely satisfactory and warrant the labor and expense. POTATO. Colorado Potato Beetle. — Is so familiar to everyone that it is hardly necessary to give any description of the destructive creature. The adult beetles come out of their winter hiding places about the end of May and feed at once upon the earliest appearing potatu plants; soon after this the females lay their bright orange colored eggs on the under side of the leaves in batches of various numbers up to fifty or more. The grubs hatch out in about a week and set to work to devour the foliage ; their dark orange color renders them somewhat conspicuous, so that an attack can hardly fail to be no- ticed. When fully grown the insect changes to the pupal stage in a cell a few inches below the surface of the ground. A period of about eight weeks is required to complete a life cycle, and then a second brood of beetles appears, lays its eggs and starts new colonies of grubs; the third brood comes out in September and may be ob- served crawling or flying about in search of winter quarters. The broods are by no means distinct, as all the grubs do not mature at the same time, consequently the insect may usually be found in all its stages at any time during the summer. The well-known and long-tried remedies are Paris green or arsenate of lead combined with Bordeaux mixture, the latter in- gredient assisting in warding off the attacks of fungous diseases and also in destroying Flea-beetles, when they are present, as they com- monly are. Spraying should be done early in June as soon as any grubs are to be seen, again a month later, and three times, at in- tervals of a fortnight, between the end of July and the first of September. Three-Lined Potato Beetle. — Looks very like the Striped Cu- cumber beetle, but is larger and of a darker yellow color. Before the coming of the Colorado beetle this was the chief insect enemy of the potato, but now, though common, it is not usually particularly destructive; its life-history is much the same, the adult beetle com- ing out in the spring and laying her eggs on the under side of the leaves of the young plants; these are yellow in color and are laid along the midrib of the leaf. The larvse have the extraordinary habit of piling their excrement on top of their backs, possibly as a protection against their enemies, and thus present a disgusting ap- pearance. The grubs appear in June and go through their trans- formation in time for another brood to come forth in August; the beetles from this later brood do not emerge till the following spring. When this insect is at all abundant, it can be easily con- trolled by the application of Paris green ; the measures everywhere taken to check the Colorado beetle have no doubt prevented this species also from becoming numerous. Potato Flea-Beetle. — Is one of the most serious pests of tlie potato plant. The tinv creature — it is less than one-twentieth of ENTOMOLOGY 16o an inch long — eats small holes all over the surface of the leaves and causes much injury in this way; but a worse result is that the spores of the fungous diseases called "Blight" find a suitable place in these holes for germination and the complete destruction of the leaf soon follows. Flea-beetles as a class have already been referred to; it is unnecessary, therefore, to do more than state that spraying with Bordeaux mixture is a satisfactory remedy for both the insect and the blight. Blister Beetles are often reported as appearing suddenly in great swarms in the potato fields and greedily devouring the foliage. An account of them has already been given under insects attacking Beets and Spinach. Potato Stalk-Borer is an occasional cause of injury to the plant in this country, but in some of the States to the west and south it is considered almost as great a pest as the Colorado beetle. As the name indicates, the attack is made by boring the stalk ; this is done by the grubs, which are whitish in color and without legs. The small beetles, about a quarter of an inch long, are ashen-gray in color and belong to the family of weevils or snout beetles, having the head developed into a long beak ; the base of the wing-covers is marked with three distinct black spots, which readily distinguish it from similar species. About the month of June the parent makes a hole in the stalk of the potato with its snout and deposits an egg and repeats the operation a number of times. The grubs which hatch from them burrow up and down in the stalks, devouring the interior, and when full-grown, about the beginning of September, form their cocoons inside the stalk near the base, of the plant ; the beetles emerge later on, but remain in this retreat all winter. No application of poison is of any avail, as the grubs are out of reach in the stalk, but much may be done to exterminate the insect by cleaning up and burning all the remains of the plants after the potatoes are dug in the fall ; this is advisable also in order to destroy the germs of fungous diseases. RADISH. Radishes are very liable to attack and serious injury when they first come up in the seed beds by the minute Flea-beetles described among the insects that are general feeders ; cheese-cloth screens are found to be the best protection. The Radish-maggot is the same or a very closely allied species to that which attacks the roots of cab- bages, and may be treated in much the same way; protection with cheese-cloth- is by far the simplest and entirely effective method of securing perfect radishes in the spring. INSECTS AFFECTING RHUBARB. Rhubarb Snout-Beetle. — Rhubarb is usually free from insect pests, there is, however, a long, slender snout-beetle, which is to be found early in the spring and late in the fall, resting on the plants. It is dark grey in color and covered with a rust-colored powder that rubs off easily. This beetle is the parent of the white, grub-like borer that tunnels in the leaf and flowcrstalks, and the eggs of which are laid in small cavities cut in the tissue of the plant. It is c«;J 166 INSECTS AFFECTING VEGETATION that the practice of removing the old leaves regularly will take care of the pests, as the borers will in this way be destroyed just as fast as they come, and the new stalks will be found to be free after a little time. The insect also feeds on dock, and for this reason, it is well to destroy all the docks in the vicinity of rhubarb plants. INSECTS AFFECTING THE SQUASH. Squash-Vine Borer. — It often happens that squash-vines sud- denly wilt, just as they are getting a nice start. This may be due to one of several causes, sometimes a bacterial disease is the cause and sometimes one of the fungous diseases; often, however, one finds on examination that there is a grublike borer in the hollow stem, and that a tunnel has been gnawed down into the roots. Here the borer dwells, sometimes above and at others below the level of the soil. When full-grown, this grub leaves the tunnel and pupates near by in the soil. In the following spring the adult appears. The adult is a very pretty insect belonging to the family of moths known as clear-wings, because the wings of many of its members are partially transparent. The moth of the squash-borer measures about one and one-fourth inches across the extended wings, from tip to tip, the front wings being green and the hind- wings clear. The body is reddish except for the basal part which is green like the front-wings. The hind-legs each bear a fringe of long hairs. The species is said to be single brooded in this part of the country. Further south it is double-brooded. The remedies for this pest are three in number. The results are most satisfactory when all thre^e are used together. Trap Plants. — Fortunately the borer works in summer-squash as well as in the winter varieties, the summer-squash planted be- tween the rows of winter-squash, will attract the majority of the borers. Later, when they have all become settled in their burrows, the early varieties may be pulled up and burned leaving the later ones free from the borers. Many times it is possible to cut out the larvae by making a longitudinal slit in the vine. Last, but perhaps best of all, the vines may be induced to put out roots at short intervals by placing a little soil over the joints, thus supplying plenty of food to the vine even after the tap-root has been destroyed. If the plant escapes until it has commenced to run well, it is easy to induce roots to grow by pulling a couple of hoefuls of soil over some of the joints. Cucumber-beetle (see Insects of the Cucumber). Squash-bug (see Insects Affecting the Cucumber) . TOMATO AND TOBACCO. These two plants may be associated together, as the same in- sects are liable to attack both. Cutworms early in the season are very destructive to the young plants, but may be warded off by the use of the poisoned bran-mash. The leaves are liable to be attacked by the Flea-beetles, the Tarnished Plant-bug and Grasshoppers. The most conspicuous enemy of both plants is Five-Spotted Hawk Moth, or Tomato Worm. — This is a large caterpillar, attaining to a length of nearly four inches when fully ENTOMOLOGY 1G7 grown and correspondingly thick ; it has a series of oblique pale lines along the sides and a prominent tail; in color there are three vari- eties, pale green, dark green and almost black. They are very vo- racious feeders, and soon strip the foliage from a plant; but being so conspicuous they can be readily got rid of by hand picking. When growth is completed, the caterpillars burrow into the earth and form a cell in which they transform to a dark brown chrysalis, which has attached to the head and underside of the thorax a pro- jection resembling the handle of a jug and containing the enor- mously long sucking tube with which the moth is provided. Usu- ally it remains buried in the ground until spring, but occasionally some of the moths come out in the autumn if the weather should be warm. They are large, handsome, swiftly flying creatures, ashen- gray in color with a variety of paler and darker lines and markings ; the abdomen is ornamented with five large orange spots on each side which give the insect a very characteristic appearance. These To- mato worms have often been supposed to be poisonous, and many marvellous tales have been told of their deadly stings and bites; they are, however, quite incapable of either stinging or biting, and may be handled without the least danger. Corn Ear-Worm. — This, which has been described above, fre- quently attacks green tomatoes before they are fully grown and bores large holes which utterly destroy the fruit. It also feeds on tobacco, eating into the unripe seed capsules and devouring the con- tents. In the case of tomatoes the only plan seems to be to cut off and destroy all the infested green fruit. Where tobacco is ex- tensively grown, if there should be an annual attack of these cater- pillars, it would be advisable to grow a strip of corn as a trap-crop along the sides of the field; the moths would lay their eggs on the young ears of corn in preference to the tobacco plant, and these could be gathered and burnt or fed to pigs before the worms attain to maturity. TURNIPS. Turnips are attacked by several of the insects already described as enemies of the cabbage, viz., the Zebra Caterpillar, the Diamond- back Moth, the Cabbage Maggot, and the same species of Plant- louse (Aphis). The last mentioned insect has been more complained of recently by turnip growers than any other pest ; its ravages in late summer and autumn of 1908 were widespread over Canada, due to the prolonged dry, warm weather which was favorable to their in- crease, and in many cases whole fields were rendered worthless. The usual remedies, kerosene emulsion and strong soapsuds, were found effective when applied in time ; but in most cases the attack was not noticed till the damage was beyond repair. Much may be accom- plished by keeping a sharp look-out for the colonies of plant-lice when hoeing is being done ; an affected plant should be at once cut out and the lice crushed under foot ; early measures of this kind will prevent a serious infestation later on. Turnip Flea-Beetle. — Differs from our other species in having a wavy yellowish stripe down each side of the wing covers, but its 168 INSECTS AFFECTING VEGETATION habits are much the same as those of the rest of the family. Its attacks on the young plants when they first come up are often very serious and prevent the growth of a large proportion of the crop, necessitating a resowing. As the first brood of beetles disappears toward the end of June it has been found that turnips sown during the third week of that month escape attack, and produce as good a crop as those sown earlier. When the beetles are observed to be attacking the young plants they may be got rid of by dusting with Paris green and land plaster, one pound of the poison to twenty of the plaster ; this should be done when the plants are moist with dew in the early morning. A condition of the soil which induces rapid and vigorous growth is of great importance, as it enables the young plants to get beyond the danger point before much injury has been sustained. INSECTS AFFECTING THE SWEET POTATO. The Sweet Potato Flea-Beetle. — This is a small bronze or brassy- brown beetle about 1/16 of an inch long. The eggs have not been observed but the larva and pupa have been found on birdweed roots. The plants should be dipped in arsenate of lead, one pound to six of water, before being set. The Two-Striped Sweet Potato Beetle. — This is one of the Gold- Bugs or Tortoise-Beetles. Its color is rather dull brownish-yellow with only a faint golden lustre while on each wing cover there are two black stripes; the insect is ^4 inch long. The larva is dirty yellowish^white. The Golden Tortoise-Beetle. — This species is a uniform golden yellow and measures XA inch in length. The larva is dark brown and carries its excrement about on an anal fork. The Black-Legged Tortoise Beetle. — This beetle is 5/16 of an inch in length, golden but not so brilliant as the foregoing and has three black spots on the wing covers and black legs. The larva is pale yellow. The measure used against flea-beetles, dipping, will prove suffi- cient to control this group of beetles ordinarily, but should the larva become numerous later, spraying with arsenate of lead, 2 lbs. to 50 gallons of water, should be effective. — (N. J. Agr. Exp. Sta. Bui. 229.) BULLETINS USED ON VEGETABLE INSECTS. Bul. 171, Ontario Dept. of Agr., also Cir. 135, U. S. D. A. B. E. ; Bui. 233, Mich. Agr. Exp. Sta. ; Bul. 114, Ky. Agr. Exp. Sta. ; Bul. 2, Va. Truck Exp. Sta. ; Bul. 45, Ga. Agr. Exp. Sta. ; Bul. 45, Fla. Agr. Exp. Sta. INSECTS AFFECTING GRAIN. [The pests of wheat and corn include all the principal in- jurious insects that attack barley, rye, oats and all other grains. For such injuries refer to corn and wheat insects.] INSECT ENEMIES OF CORN. The insect enemies of Indian Corn are legion, and may be found attacking every part of the plant, root and stem, leaves and ENTOMOLOGY 169 ears, the tassel and silk, and the ripe harvested corn ; about 350 dif- ferent species are recorded from North America. It is unnecessary to describe more than a few species which are always with us and against which constant warfare has to be waged. Attacking the roots we find White-grubs and Wire-worms very destructive, especially where corn is planted on old pasture land broken up a year or two before. These insects have already been described. Another serious enemy is the Corn Root-aphis, which is attended by its ant protectors; it is especially injurious to the plants when young. The winged forms migrate to various common weeds such as plantain, pigweed, etc., showing the importance of keeping fields and gardens free from these places of refuge. As soon as the tender blades of corn appear above the soil they are liable to be cut off by those nocturnal marauders, the Cutworms, which can be circumvented by the use of the poisoned bran-mash. The grubs of the 12-spotted Cucumber beetle often infest the roots of corn when the plants are young, and a great deal of loss is occa- sioned by them. Later on, as the plants grow bigger, they may be attacked by Grasshoppers and seriously injured. The Corn Root Aphis* — The corn root aphis is by far the most injurious of the six species of aphids that infest corn. It sucks the sap from the roots, impoverishing the plants, and doing the most injury when the plants are small. The welfare of the root lice de- pends largely on the care bestowed on them by ants, several species of which attend them and protect the eggs over winter, besides car- ing for the lice during the growing season. The best results seem to follow rotation, together with late fall plowing in order to break up the nests of the ants. The aphids feed on other plants and like especially smart-weed, pigeon-grass, and purslane. Heavy applications of fertilizer are said to help the plants to recover from the early attacks. The aphids spread quite freely, but are worse when corn follows corn than when corn follows some- thing else. Keep out the weeds above mentioned. Southern Corn Root-Worms. — Two corn root-worms occur. One of them is the Southern Corn Root- Worm, which is a first-class corn pest, in parts of some of the states south of us. As it has not, thus far, been guilty of depredations in Michigan, we will merely refer to Dr. Forbes' full account of the creature, and state that it is said to bore, when in the larval stage, into the stalk beneath the surface of the ground, sometimes killing the plant outright, but oftener retarding it so that it-is still green when frost comes. Northern Corn Root-Worm. — Tunnels in the roots themselves, and is, when abundant, said to be even more serious. These root- worms are small grubs, white in color, and about four-tenths of an inch in length in the case of the Northern species, and about fifty- six-one-hundredths in the case of the Southern species. — (Mich. Bui. 258.) Wire-Worm. — Low ground and more especially mucky ground, is apt to be infested with wire-worms. These are slender, yellow. little creatures, cylindrical in form, and in size varying from half •For illustrations, see pages 213 and 375,' 170 INSECTS AFFECTING VEGETATION an inch to more than an inch in length. All have hard, polished skins amounting almost to shells, and six short legs just behind the flattened heads, besides a sucker-like false-foot on the last seg- ment. Wire-worms usually feed on the roots of grains, corn and other grasses, though they will not refuse potatoes when occasion offers. There are many species to be found, and while one may pre- fer corn, another wheat, and so on, they may all be considered as injurious, except those found in rotting wood, and treated together. The adults are the common snapping-beetles or click-beetles, the little fellows that jump up into the air with a click, when placed on their backs. These beetles lay the eggs from which the wire-worms hatch, and the wire-worms in turn become click-beetles after passing through a chrysalis stage in their little earthen cells in the soil. It is probable that two years are required by the larvae to attain matu- rity. The winter is passed in little cells in the soil in some cases, while in others the adult beetles emerge in the fall and hibernate. Wire-worms are primarily insects of grassland and the fact that they require two or three years to develop helps to explain why it is that they are often worse the second year after grass than they are the first, most of them being full-grown at that time. In corn, the most noticeable injury is to the seed after planting, though the larvae also feed on the roots after the corn is up. A long series of experiments by Professors Comstock and Slingerland of Cornell University, failed to show any practicable method of treat- ing the seed so as to prevent injury by wire-worms. They did show, however, that late fall plowing killed many of the pupae and adults by breaking open the earthen cells in which they were. They failed also to kill the wire-wrorms by any of the commercial fertiliz- ers or insecticides, unless these were used in excessive quantities. Prof. S. A. Forbes, State Entomologist of Illinois, proposes a rotation of crops in which the clover shall always follow grass, and corn shall always follow clover. Plow the grass in early fall, and sow clover, either with oats, wheat or rye. Allow the clover to stand two years and follow with corn. On general principles it is well to use wood-ashes where obtainable, because of their tonic effect on the plants. It is understood, of course, that these practices are recom- mended for aggravated cases of wire-worm infestation and not for regular use in the absence of the pest in dangerous numbers. Corn and Timothy Bill-Bug. — The timothy and corn bill-bug is a small beetle that habitually works in timothy, where its work is naturally more or less obscure. When, however, corn follows in- fested timothy, or when corn is planted near infested timothy, it is likely to be attacked. The beetles are less than one-fourth of an inch long, and are black. They belong to the group of snout-beetles. In young corn they tunnel directly into the plants just above the crowns, causing the plants to wilt and usually to die. Fortunately the beetle pro- duces but one generation each year, and the injury, so far as corn is concerned, is done by the adult beetles alone. ENTOMOLOGY 171 While the bill-bug is known best by its work on corn, it is really timothy that suffers the most from its ravages. Working as it does in the bulbous roots of the timothy, it is able to pass unnoticed un- less it occurs in very large numbers. Here in the timothy bulbs are passed the immature stages, the adults emerging at just the right time to attack the young corn. The moral is not to plant corn after timothy in places Avhere one has reason to fear the presence of the beetles. When the beetles have once come out and done their work in the corn, there seems to be no danger from re-seeding, for there is but one generation each year and the beetles require timothy for their early development. Cut Worms. — Just about the time that the danger from crows has abated somewhat, the young sweet-corn is often called upon to withstand an attack by cut-worms. There are striped cut-worms, dark, light, glassy, greasy and many other sorts, each belonging to a different species, and each developing into its corresponding moth. The moths or millers are nocturnal in their habits, and are spoken of as owlet-moths because of their habits and the shape of their heads. Cut-worms naturally work on sod land, and for this reason, it is well to avoid planting corn, tobacco, tomatoes or anything else especially liable to their attacks directly after grass. Then too, the great majority of our cut-worms pass the winter in a partially grown condition, and when spring comes, and the sod and roots are re- placed by a comparatively smaller number of corn plants, the worms are hardly to be blamed for feeding on them. Sod land, then, has its disadvantages when used before a crop liable to attack by cut- worms. It is also a menace when adjacent to a corn-field, for the worms will travel quite a distance from their breeding grounds in order to get at their favorite food. They work at night, traveling on the surface of the soil, and cutting off the plants low down at or just below the soil level. They cut off much more than they can use and then retire before daybreak, burrowing lightly and hiding often near the plant just cut off. One worm will forage night after night and destroy many times as much food as could be eaten. One can not help wondering at its wasteful habits. It has been suggested that the food is cut in order to let it wilt before it is eaten. Wet food does not seem to agree with some caterpillars, neither does that which is too vigorous and turgid. It is not unreasonable to suppose that much of the food is cut in order that it may wilt and be ready for future use, rather than from mere wanton destructiveness. As has been stated, many of the cut-worms pass the winter in a partially grown condition, just beneath the surface of the soil. Occasionally, in winter, during a sudden thaw, the larvae will crawl up on top of the snow, being driven upward by the water from the melting ice and snow. In such cases they seldom get back into winter quar- ters, but perish as soon as it freezes again. The writer has seen the snow thickly dotted with cut-worms on such occasions. Many para- sites feed on them and shrews and birds devour quantities. The measure that has been most successful in the past, is the use of poisoned baits, when the trouble is on a large scale. On a 172 INSECTS AFFECTING VEGETATION very small scale, other methods are more effective. Of the baits used, clover is the favorite. A goodly pile of clover should be cut, and while it is still fresh and green, it should be wet down with paris- green and water, using about half a pound of poison to a barrel of water, then, late in the afternoon, so that it will keep fresh as long as possible, twist bunches of this wetted clover in wads, more or less compact, and throw out over the field at short intervals. If the field to be protected be near a field in sod, then place an extra amount on the threatened side. The cut-worms love clover and oftentimes they will hide under such wads of fresh green food in the morning after a night's travel, eating a little of the poisoned food before hiding away. Poisoned pieces of turnips will do if clover is not to be had. Poisoned bran, sweetened with a little molasses and made into moist balls the size of a plum, has been recommended, and Mr. Sir- rene, of the New York State Experiment Station, recommends dry bran mixed with dry paris-green, sowed on the surface of the soil by means of a hand drill. In any case do not use such baits of bran unless stock and poultry are excluded or when partridge and quail are likely to get it, and do not expect to find the dead worms in the morning unless you are willing to sift the top soil for some dis- tance about each bait, for the pests always bury themselves before dying. The only way to judge of the death of the larvae is by the cessation of their work. The habit of passing the winter in a. partially grown condition or in the egg state, at once suggests fall plowing as a palliative meas- ure, unless it be undesirable for cultural reasons. The Sod Web-Worms, or Root Web-Worms. — Every observer of insect life has noticed, as he walks through grass on lawns or mead- ows in summer, multitudes of small white or grayish moths rising before him, flying a short distance, and then lighting to rest on the grass, head downward, with the body parallel to the blade. These moths, or millers, if examined when at rest, are seen to have the wings folded around the body in a way to give them a cylindrical form instead of the usual triangular one of ordinary moths. These are the parent insects of small, slightly bristly, reddish caterpillars which live abundantly in the turf, hidden away by day in a silk- lined burrow among the roots of the grass, but becoming active at night, when they feed especially upon the underground part of the stem of the plant, sometimes also upon its roots or blades. These caterpillars average about half an inch in length when full grown, are pinkish red or brownish, and covered with rows of comparatively smooth dark spots, from the center of each of which springs a rather coarse hair. They differ from cutworms in their habit of quickly wriggling away when picked up or disturbed, and making active efforts to escape. Cutworms, on the other hand, are sluggish, and take disturbance quietly, simply curling up and taking their chances. Not infrequently the web-worms become so abundant as to cause brown or deadened spots in a lawn or meadow, sometimes, indeed, in seasons unfavorable to the growth of grass, deadening the turf ENTOMOLOGY 173 as thoroughly as white grubs or cutworms can do. When land so infested is planted to corn, this plant is very likely to be heavily injured, or even completely destroyed over considerable areas in early spring. The injury done is somewhat like that due to cut- worms, and is largely under ground, but, on the other hand, the stems are rarely completely severed until the whole plant is eaten up. Commonly the first injury to the plant is done by gnawing the outer surface beneath the ground and about the roots. Then the caterpillar works upward, eating a superficial furrow or burrowing lengthwise along the center of the stem. The leaves are also fre- quently eaten, the lower ones first, and then the upper ones. The tips are eaten off, or irregular elongate holes are eaten through the blades. The injury being done at night, search must be made for the author of it by day by digging around the affected hills. The web-worms will commonly be found just below the surface, each in a retreat formed by loosely webbing together a mass of dirt, more or less cylindrical in shape, an inch and a half to two inches long, and about half an inch through. Within this mass is a silk- lined tube opening at the surface of the ground next to a stalk of corn, and within this specially prepared domicile a single caterpil- lar is secreted. Injuries due to these web-worms are commonly at- tributed by farmers to cut-worms, and the caterpillars themselves are similarly confounded. This error would signify but little ex- cept for a single important difference in the midsummer life his- tory which has its bearing on the proper time of plowing the sod in spring, and that for planting or replanting the corn. Cutworms are never protected by an underground web, are much larger than web-worms, make no active efforts to escape when disturbed, but curl up and remain inactive, and are without rows of conspicuous shining spots upon the body, these being represented by small and inconspicuous ones. The injury to corn by the sod web- worms is not uncommon in fields planted on sod ground, and as it begins quite early and may last some weeks, it is fully as serious as a similar attack by cutworms or white grubs. Frequently more or less extensive replanting is re- quired, and sometimes whole fields are completely destroyed two or three times in succession. Unless the damage they do is very serious it is hardly no- ticed, or, if noticed, attributed to other causes. As the larvae live a retired life, close to the surface, eating mostly at night and remain- ing in their nests during the day, they are rarely seen. Like most larvae they feed most voraciously just as they are completing their growth ; consequently, when the damage is noticed most of the larvae are hidden in their retreats where they pupate. In these places none but an experienced entomologist would find them, or would think of associating the damage done with the harmless appearing moths that fly later. Hardly any farmer would think seriously of the loss of only one stalk of grass in ten, yet the aggregate for the country at large would be enormous. Not only is the damage to a crop where noth- 174 INSECTS AFFECTING VEGETATION ing short of a serious injury would attract attention, but the damage is distributed throughout the growing season. As a general rule, each species is most destructive at a different time from the other species of that locality; hence, species of Crambus prey upon the grass as a succession of small armies. Could the loss caused by these species come at one time in the year their destructive power would be better appreciated. Less than a third of the species may be classed as of economic importance, but these possess a capacity to cause almost infinite loss if the conditions are favorable. Besides the injuries to corn, grass, and oats already mentioned, wrheat and rye have been injured by vulgivagellus, tobacco by lute- olellus (caliginosellus) , and cranberry by hortuellus, a species not yet reported from corn. There are about sixty species of the genus Cram-bus in the United States. So far as known they are of very similar habit, and it is quite likely that any of them living habitu- ally on grass will injure corn if this is exposed to their attack. The species notably injurious to this crop will consequently depend, in all probability, upon those which happen to predominate in the grass at the time the field is plowed, and as these predominating species differ from year to year, the list above given is not to be re- garded as final. — (Bui. 95, 111. Agr. Exp. Sta.) The young caterpillars form their web-lined nests immediately upon or just under the surface of the soil, strengthening them by the addition of bits of grass or particles of dirt to the surface. They commonly cut off the blades of grass and draw the ends down into the nest so that they can feed without leaving it. The facts concerning these web-worms all admonish the farmer to break up a grassy turf as early in the fall as practicable prelim- inary to planting the ground to corn ; the middle of September is as late as safety permits. If, however, this is not done until spring, it may best be postponed, so far as web-worm injury is concerned, in most cases, until the latter part of May. If an infested meadow or pasture is plowed earlier than this, when the larvae are still young, they will probably live to attack the corn when it appears; and if plowing is postponed later, until the first brood of moths have emerged, they are likely to lay their eggs in the grass before plow- ing, and thus to give origin to a brood of caterpillars, which, being quite young when the corn comes up, will make a long-continued at- tack upon it, against which replanting will be of no avail. — (Bui. 95, 111. Agr. Exp. Sta.) Burrowing Web-Worms. — These species, treated among the less important insects of the corn plant, are mentioned here merely to distinguish the larva of this group from the other web-worms, which it resembles somewhat in habit and injury to corn. It inhab- its, however, a vertical cylindrical burrow penetrating the earth to a depth varying from six inches to two feet or even more. It is about the size of a common cut-worm, but differs by its dull velvety sur- face and its colors, varying from silvery gray to brown, by the rows of polished spots on the body, and by its greater activity and more loosely jointed structure. ENTOMOLOGY 175 The Stalk-Borer. — This well-known caterpillar, often called the heart worm because of the character of its injury to corn, may be at once known wherever it is seen by the peculiar break in the striping of the body at the middle. It is about an inch long when full grown. The general color varies from purplish brown to whitish brown, ac- cording to age, and it is marked with five white stripes, one running down the middle of the back, and two on each side. These side stripes are interrupted, being absent on the first four segments of the abdomen, giving the larva an appearance as if it had been pinched or injured there. The stripes nearly vanish as the larva matures. The head and top of the neck, and the leathery anal-shield at the opposite end of the body are light reddish yellow, with a black stripe on each side. Its presence in a young stalk of corn is very clearly indicated by the wilting, breaking down, and death of the top, and by the presence of a round hole in the side of the stalk, plugged with the brown excrement of the caterpillar within. It infests a great variety of other plants in a precisely similar way. It is most noticeable in early spring in blue-grass, by road- sides, or around the borders of a field, its presence there being be- trayed by the whitening of single heads of the grass while all the rest of the plant is green. At this time it is of small size, and finds sufficient food within the grass stem ; but later it is compelled to re- sort to thicker-stemmed plants, and it is at this time that it may ap- pear in fields of corn. — (Bui. 95, 111. Agr. Exp. Sta.) Going in usually from outside the field, its injury is, as a rule, almost wholly confined to the outer rows. It rarely does any serious general damage to corn, and it has also been occasionally found in- juriously abundant in fields of wheat. It is probable that where the injury is not limited to the margins of the field, but is general throughout its area, the eggs were laid in fall in grass or thick- stemmed weeds in corn-fields, where these have sprung up profusely after the corn has been laid by. The burrow which the stalk-borer makes within the stem runs upwards from the entrance opening, and of course varies in size with the growth of the larva. Sometimes in leaving a stalk it makes a new hole above that by which it entered, and it may in this way burrow in succession several different stalks and several different kinds of plants. Corn is injured by it while from two to ten inches high. It is only one of several insects which produce this general effect at this time, but its own injury may be at once distinguished by the round hole which it leaves in the stem of the infested plant. The caterpillar, when full grown, pupates, as a rule, within its last burrow, commonly below the opening at which it entered — seemingly a precaution against its destruction by the withering and breaking away of the upper part of the injured plant. The pupa is light mahogany-brown, about three-fourths of an inch in length, and bears at the tip of the body a pair of spines. From it comes out a fawn-gray or mouse-colored moth, with the outer third of the wings paler and bordered within by a whitish cross-line. Other 176 INSECTS AFFECTING VEGETATION specimens have some white spots on the disks of the wings. The moth is nocturnal, and has been taken by us flying about electric lights, and also at sugar. The eggs have not as yet been found. There is but one brood in a year, and by the end of June the caterpillars are over half grown, and have mostly left the grasses in which they made their start and entered the thicker-stemmed plants, of course including corn. Fortunately, injuries by this insect are not of a kind to require special measures of prevention or remedy. It is, of course, impos- sible to poison the larva in the corn-field, and the breeding habits of the insect are not such as to enable us to destroy it in the pupa state by any ordinary operation. If headlands and other grassy lots adjoining corn show in early spring an unusual abundance of these insects, it might be worth while to mow the infested turf and carry away and feed the cut grass promptly, before the caterpillars could escape to enter the corn. — (Bui. 95 111. Agr. Exp. Sta.) Larger Corn Stalk-Borer* — In many southern cornfields a heavy wind late in the season, before the corn is matured, does great dam- age by breaking the plants off at the surface of the ground, thus ruin- ing them. An examination of these broken stems will, in most cases, show that they have been greatly weakened by the burrows of a larva or caterpillar. This larva is known as the larger corn stalk-borer. Its work is largely within the stem of the plant and is so ooncealed that, in most cases, unless weather conditions make it conspicuous, the presence of the insect passes unnoticed. — (Cir. 116, B. of E., U. S. Dept. of Agr.) This insect seems to have been originally an enemy of sugarcane and to have first transferred its attention to corn in the southern part of this country, where corn and cane are grown over the same terri- tory. In the United States this borer is found almost universally throughout the South, from Maryland to Louisiana and westward to Kansas. Corn is damaged by these caterpillars in two ways. First, in the early part of the season, while the plants are small, they work in the throat of the young corn, and if the tender growing tip within the protecting leaves is once damaged all chances that the plant will become a normal production specimen are gone. In many sections of the South this is commonly known as bud-worm injury, and though there are several other insects which cause a similar mutila- tion of the leaf, a very large proportion of the so-called bud-worm damage may be charged to this insect. The effect of its work on the leaves of the young corn plants is similar to that resulting from attacks by the corn billbugs and is evidenced by the familiar rows of small circular or irregular holes across the blades of the plant. The other form of serious damage chargeable to this pest occurs later in the season. The larvae, having then left the leaves and de- scended to the lower part of the stalk, tunnel in the pith. If the larvae are at all numerous in the stalk, their burrows so weaken the plant that any unusual strain will lay it low and destroy all chance of its maturing. * tiee p