/ Digitized by the Internet Archive in 2011 with funding from LYRASIS members and Sloan Foundation http://www.archive.org/details/gypsymothOObrit Bulletin 375 August, 1935 THE GYPSY MOTH W. E. BRITTON Connecticut Agricultural (Experiment Station CONNECTICUT AGRICULTURAL EXPERIMENT STATION BOARD OF CONTROL His Excellency, Governor Wilbur L. Cross, ex-officio, President Elijah Rogers, Vice-President Southington William L. Slate, Treasurer New Haven Edward C. Schneider, Secretary Middletown Joseph W. Alsop Avon Charles G. Morris Newtown Albert B. Plant Branford Olcott F. King South Windsor Administration. STAFF William L. Slate, B.Sc, Director. Miss L. M. Brautlecht, Bookkeeper and Librarian. Miss Katherine M. Palmer, B.Litt., Editor. G. E. Graham, In Charge of Buildings and Grounds. Analytical Chemistry. E. M. Bailey, Ph.D., Chemist in Charge. C. E. Shepard Owen L. Nolan Harry J. Fisher, Ph.D. \ Assistant Chemists. W. T. Mathis David C. Walden, B.S. J V. L. Churchill, Sampling Agent. Mrs. A. B. Vosburgh, Secretary. Biochemistry. H. B. Vickery, Ph.D., Biochemist in Charge. Lafayette B. Mendel, Ph.D., Research Associate (Yale University). George W. Pucher, Ph.D., Assistant Biochemist. Botany. G. P. Clinton, Sc.D., Botanist in Charge. E. M. Stoddard, B.S., Pomologist. Miss Florence A. McCormick, Ph.D., Pathologist. A. A. Dunlap, Ph.D., Assistant Mycologist. A. D. McDonnell, General Assistant. Mrs. W. W. Kelsey, Secretary. Entomology. W. E. Britton, Ph.D., D.Sc, Entomologist in Charge, State Entomologist. H. Walden, B.Agr. ] M. P. Zappe, B.S. Philip Garman, Ph.D. Roger B. Friend, Ph.D. Neely Turner, M.A. Assistant Entomologists. John T. Ashworth, Deputy in Charge of Gipsy Moth Control. R. C. Botsford, Deputy in Charge of Mosquito Elimination. J. P. Johnson, B.S., Deputy in Charge of Japanese Beetle Control. Miss Helen A. Hulse 1 ,, , . Miss Betty Scoville ) Secretaries. Forestry. Walter O. Filley, Forester in Charge. H. W. Hicock, M.F., Assistant Forester. J. E. Riley, Jr., M.F., In Charge of Blister Rust Control. "Miss Pauline A. Merchant, Secretary. Plant Breeding. Donald F. Jones, Sc.D., Geneticist in Charge. W. Ralph Singleton, Sc.D., Assistant Geneticist. Lawrence C. Curtis, B.S., Assistant. Soils. M. F. Morgan, Ph.D., Agronomist in Charge. H. G. M. Jacobson, M.S., Assistant Agronomist. Herbert A. Lunt, Ph.D., Assistant in Forest Soils. Dwight B. Downs, General Assistant. Miss Geraldine Everett, Secretary. Tobacco Substation Paul J. Anderson, Ph.D., Pathologist in Charge. at Windsor. T. R. Swanback, M.S., Agronomist. O. E. Street, Ph.D., Plant Physiologist. Miss Dorothy Lenard, Secretary. Printing by Quinnipiack Press, Inc., New Haven, Conn. CONTENTS PAGE The Gypsy Moth 625 Distribution Abroad and History in America 625 The Gypsy Moth in Other Countries 625 Appearance and Spread in the United States 625 Discovery and Spread in Connecticut 627 Damage and Destruction qf Trees 628 Food Plants and Injury 628 Defoliation of Trees 629 Life and Habits 630 Methods of Spread 630 Life History 631 Description 633 Natural Enemies 634 Imported Parasites 636 Prevention of Spread 639 Barrier Zone 639 Quarantine Restrictions 639 Control Measures 641 Scouting and Creosoting Egg-Clusters 641 Banding Trees 643 Cutting Brush 643 Spraying 643 Summary 645 The cover cut (Figure 76) shows gypsy moth caterpillars feeding on an oak leaf. About natural size. Figure 77. Diagram showing life history of gypsy moth. THE GYPSY MOTH* Porthetria dispar Linn. W. E. Britton, State Entomologist The gypsy moth, one of the hardiest and most destructive insects known, came to Connecticut by way of Massachusetts. For nearly 45 years that state has been engaged in an attempt to control the pest. In spite of these early efforts, however, the moth kept on spreading and soon reached other states where it has also caused great damage. Of course in the early days of the infestation our modern effective control methods had not been de- veloped. It was necessary to try new measures and note results. Since 1906, when Congress first made an appropriation for this work, the Federal Bureau of Entomology has cooperated with the various states in suppressing the gypsy moth. It was in the same year (1906) that Connecticut first used state funds for this purpose, and up to June 30, 1934, about $806,504.87 has been expended by the state forces. This sum, together with federal appropriations including emergency relief funds, makes a total of more than $2,000,000 that has been expended officially for the control of the gypsy moth in Connecticut. Since 1891 the states, the Federal Government of the United States and the Dominion of Canada have spent upward of $41,000,000 in all the infested areas. DISTRIBUTION ABROAD AND HISTORY IN AMERICA The Gypsy Moth in Other Countries The gypsy moth occurs in central and southern Europe, northern Africa, and throughout southern and central Asia, including Japan and Ceylon. On the European continent the insect becomes abundant at intervals and causes great damage in certain areas. In general, however, it is held in check by its natural enemies and is nowhere such a serious pest as it has proven to be in this country. It is now considered a rare insect in England. As most of the earlier collections contained plenty of examples of the gypsy moth and the more recent ones do not, it is fair to assume that it was formerly rather abundant there. Appearance and Spread in the United States According to the best obtainable information, the gypsy moth was first brought into this country in 1869, or thereabouts, by Mr. L. Trouvelot, *A revision of Bulletin 186, with much new matter added and some portions entirely rewritten. 626 Connecticut Experiment Station Bulletin 375 an artist and astronomer who was interested in silk culture. In order to overcome a wilt disease or "flacherie" then playing havoc in some silk worm establishments, he tried to cross the silk worm with certain other species to obtain a hardier or more resistant race of silk worms. Among other silk spinning caterpillars in their various stages, which he imported from France for this purpose, were some egg-masses of the gypsy moth. Some of the caterpillars escaped accidentally from the breeding cages at his home, 27 Myrtle Street, Medford, Mass., and though he searched for them and published a notice at the time, the affair was soon forgotten. The insect was not seen for years, but by 1889 had become a serious pest defoliating many trees in this same locality. The town of Medford first raised a sum of money for its control, and in 1890 the State Legislature made its first appropriation for moth work. At first only a small area was infested, and had the knowledge and ex- perience which we now possess then been available, the pest might perhaps have been exterminated. But methods had to be worked out, men trained, the insect studied, and as many of the earlier methods finally were shown to be ineffective, the insect was not eradicated. Finally, after 10 years, the Massachusetts legislature in 1900 refused to make further appropria- tions and the state suppression work ceased. At that time the infested area covered 359 square miles in the vicinity of Boston. For five years no state work was carried on, though many private owners and probably some municipalities controlled the pest on the land under their jurisdiction. In 1905 the gypsy moth had spread and multi- plied and become such a nuisance that state control work was resumed and has since been continued. But by that time the infested, area covered 2,224 square miles instead of 359, and extended from beyond the New Hampshire line south to Buzzard's Bay, and westward as far as Marl- borough. A large colony had also become established at Providence, R. I. It had no doubt spread considerably beyond these limits, for it was soon found in New Hampshire and later in Connecticut and in Maine. At the present time, the gypsy moth occurs in all of the New England States, but does not infest their entire area. The infested area includes : The eastern two-thirds of Connecticut, the whole of Rhode Island, all of Massachusetts except Berkshire County in the western part, the south- western third of Maine, all of New Hampshire except a few towns in the northernmost portion equivalent to about one-third of Coos County, and the eastern half of Vermont, except Orleans and northern Essex counties in the north. Separate infestations are also present on Long Island in New York, in Morris County in New Jersey, and in the vicinity of Scranton and Wilkes-Barre in Pennsylvania. These isolated infestations will probably be eradicated as many others have been, in the course of the attempt at official control. Among more than 400 infestations that have been completely wiped out, only a few can be mentioned here. Connecticut : Greenwich, New Haven, Seymour, Stonington, Wallingford and Woodbridge (Stonington after- wards again became infested) ; Ohio : near Cleveland ; Pennsylvania : Loretto ; New Jersey : Rutherford ; New York : Brooklyn, Chesterfield, Geneva, Greenport, L. I., Moriah and Mount Kisco; Vermont: Alburg, The Gypsy Moth 627 Bennington, Benson, Castleton, Danby, Essex, Fairfield, Fair Haven, Ferrisburg, Ira, Leicester, Pittsford, Rutland and Salisbury. In addition to the infestations listed above, a great many colonies have been eradicated, but later the areas became reinfested. Also many small infestations have been uprooted in the barrier zone. Discovery and Spread in Connecticut The presence of the gypsy moth in Connecticut was discovered in July, 1905, when two female moths were taken and two males seen in Stoning- ton, by Ernst Frensch, a local collector of insects. Later a few egg-clusters were noticed. Mr. Frensch communicated with this Station in February, 1906, and the writer visited him and saw his specimens and the egg- clusters. Apparently the center of the infestation was in some low brush around a pond near the velvet mill on the eastern side of the village. These egg- clusters were soon creosoted and the brush cut and burned. Later egg- clusters were discovered on some of the apple trees and shade trees in the near vicinity and scattered throughout the village. Altogether, less than a square mile seemed to be infested. In 1906, 73 egg-clusters, 10,000 caterpillars and 47 pupae were de- stroyed. In 1907, 118 egg-clusters, nearly 3,000 caterpillars and 200 pupae were destroyed. The numbers decreased each year until 1911, when only three egg-clusters were found. Although careful scouting was done in Stonington in 1912 and early in 1913, there were no traces of the gypsy moth until summer, when five caterpillars and one pupa were discovered. It seemed to be a reinfestation and this view was later confirmed by federal scouts, who found scattered egg-clusters in nearly all of the eastern border towns of the State during the following winter. The infestation in Stonington was evidently eradicated wholly by creosoting egg-clusters, seeking and crushing caterpillars and pupae under burlap bands, in cavi- ties and other protected places. Spraying with poison, as now practiced, was attempted only in a small way. Another infestation was discovered in December, 1909, in the village of Wallingford. More than 8,000 egg-clusters, nearly 9,000 caterpillars, and 100 pupae were destroyed there during the first year. The numbers were reduced rapidly, and in 1913 only two egg-clusters and three cater- pillars could be found. No gypsy moth infestation has occurred there since. Altogether less than a square mile of territory was infested, and the control measures practiced were creosoting egg-clusters, pruning and scraping trees, filling and covering cavities, cutting and burning worthless trees and brush, banding trees with burlap and with tanglefoot, and spraying trees with lead arsenate. It is uncertain how the gypsy moth reached Wallingford, but probably egg-clusters were carried there unnoticed on a crate or packing box. The center of infestation seemed to be just north of Center Street, in the rear of some stores that had received many shipments of goods from eastern Massachusetts. In later years several localities in the town of Wallingford became infested when the insect spread westward. 628 Connecticut Experiment Station Bulletin 375 In May, 1913, windspread must have occurred along the Rhode Island border. The following winter the gypsy moth appeared in 10 towns, including most of those adjoining Rhode Island, and, in some cases, in the second tier of towns as well. In 1915 the pest was found in 10 additional towns, making 20 alto- gether. By 1917 this number had increased to 22, and by 1918, to 29 towns, all in New London and Windham counties. In 1920, and possibly in 1921, windspread carried the pest into other counties, adding 35 towns to the list, and making in all 64 infested by the gypsy moth. In 1923, when the control or barrier zone was established, there were 100 Connecticut towns infested. Since then the pest has invaded a few more. However, with the present system of careful and thorough work in the barrier zone, only slight future changes may be expected in the relationship between infested and non-infested towns. At this writing, 60 are in the barrier zone or southwest of it, and 109 are in the quaran- tined area, although many of them are only slightly infested. With the prospect of large federal allotments of relief funds and additional CCC camp work on gypsy moth control, there is a possibility that some of the westernmost towns in the quarantined area may soon be freed from infestation and quarantine. DAMAGE AND DESTRUCTION OF TREES Food Plants and Injury The caterpillars of the gypsy moth damage trees, shrubs and other plants by stripping them of their leaves. Formerly it was supposed that they would attack almost any kind of foliage, ash being perhaps the most nearly immune of any of our broad-leaved deciduous trees. In the pub- lication, "The Gypsy Moth," by Forbush and Fernald, is given a list of several hundred food plants, containing nearly all the common cultivated ones. But more recent investigations at the parasite laboratory, Melrose Highlands, Mass., conducted under the direction of Mr. A. F. Burgess, show that the caterpillars in their first and second stages are not able to live on some of these plants even though they may feed on them in later stages of development. For instance, though the caterpillars in their later stages will feed upon pine, and have killed large areas of pine mixed with hard wood in Massachusetts, they must have some deciduous foliage for food in their first and second larval stages. Considering the matter from this standpoint, it seems quite possible to cut out all other growth, leaving solid stands of pine or other conifers which, with only slight protection, may escape destruction. By the use of tanglefoot on the trunks of the trees around the margins of such an area, little damage will result. The caterpillars are partial to fruit trees, willow, oak, poplar and rose. But when they are abundant, food becomes increasingly scarce and they will feed upon a great many different trees and plants. The Gypsy Moth 629 Defoliation of Trees Wherever gypsy moth infestations are permitted to build up without artificial- check, as frequently occurs in undiscovered woodland colonies, severe defoliation or "stripping" of the trees may take place. Extensive defoliation has occurred at various times in the past in eastern Massa- chusetts and many acres of woodland trees were killed. In 1918, certain woodland areas near the base of Cape Cod were wholly or partially defoliated, and this condition has been more or less constant throughout the generally infested area in Maine, Massachusetts and New Hampshire. Even in more recent years extensive stripping has occurred in the New England States. In 1926, about 70,000 acres, and in 1927, 142,000 acres were completely or partially defoliated. In 1928, the area increased Figure 78. About 30 acres of woodland were stripped by gypsy moth cater- pillars near Groton Long Point. Photographed July 10, 1933. to 262,000 acres, and for the first time defoliation was found in Con- necticut. The stripped areas were chiefly in Maine, Massachusetts, New Hampshire, and small sections in Rhode Island and Connecticut. In 1932, a few oak trees were stripped in Brooklyn and Killingly. In July, 1933, just after the close of the spraying season, a gypsy moth infestation was discovered near Groton Long Point, where the large merchantable trees on 30 or more acres of land had been partially or completely defoliated. Figure 78 shows some of these stripped trees. Soon after the females finished laying eggs, clean-up measures began. Altogether, 286,664 egg- clusters were creosoted in this place. Some of the trees stripped in 1933 failed to put out leaves, and in 1934 many of them had died as shown in Figure 79. 630 Connecticut Experiment Station Bulletin 375 LIFE AND HABITS Methods of Spread As the insect passes about three-quarters of its life cycle, including the winter, in the egg stage, there is a long period from late July until the following May when the egg-clusters may be transported on packing boxes, crates, freight cars, vehicles, nursery stock, lumber, quarry, or other products, which have remained for a time in July or August in the infested region. This is especially true if these products have been stored, stacked, or allowed to stand where gypsy moths were abundant at the time when the eggs were laid. The egg-clusters are seldom noticed or recognized by the men handling these materials, and may be shipped Figure 79. View of trees at Groton, defoliated by gypsy moth caterpillars in 1933. Some of these trees did not leaf out in 1934. Photographed June 14, 1934. long distances into various states. This is the reason for establishing a quarantine, thus preventing all shipments going out, unless inspected and certified by a federal inspector. This method of spread will probably account for the isolated infestations at Stonington and Wallingford and for most of those in other states. The caterpillars when nearly grown, and especially if very numerous, crawl about in search of food or a place in which to pupate. They some- times board trains or other vehicles and may be transported by these means. The insect may also be carried from place to place in the pupa and adult stages. But there is less danger of spread then because the females do The Gypsy Moth 631 not fly, the pupae are usually in holes or protected places and because these stages in the life cycle are short. Windspread is probably accountable for most of the extension of the large area of infestation which has been more rapid toward the north and east than in other directions. When the caterpillars first hatch from the eggs, they are, of course, very small and are covered with hairs, some of which are bulbous and known as aerostatic hairs. Whether or not this is their real function, it is true that these first stage caterpillars are carried long distances by strong winds occurring at this time. Several years ago Mr. Burgess had a large screen placed on the Isles of Shoals, seven miles away from the nearest infested trees in New Hampshire. It was covered with tanglefoot and caught several young caterpillars. Ac- cording to the federal men, windspread explains the scattered infestations through eastern Connecticut in the spring of 1913. Of course, if the wind blows toward the center of the infested area no harm will result, but if it blows outward, the area may be greatly extended. A more extensive windspread occurred in 1920 and possibly in 1921, carrying the pest into Tolland, Hartford, Litchfield, Middlesex and New Haven counties, more than doubling the number of infested towns in Connecticut. Life History The young caterpillars, hatching from the eggs about May 1, feed and hide upon the leaves, spinning down on silken threads when disturbed. They usually feed at night and often rest on the under side of the leaves during the day, where their presence is apt to be overlooked. They molt five or six times and gradually increase in size, reaching maturity early in July. Caterpillars molting five times usually develop into males, and those molting six times become females, according to Mosher and Webber*, who have carried on many experiments and observations at the Gypsy Moth Laboratory at Melrose Highlands, Mass. During this entire larval period, the caterpillars are hairy, dark in general color and some show a predominating tint of brown while others are gray. There is much variation in size, the largest caterpillars being nearly three inches long (probably molting six times) ; most of them, however, are between two and two and one-half inches. From the time they are half -grown, they hide during the day in crevices in the bark, in cavities, or in some other dark place, presumably to escape bright sunlight, and are found on the leaves chiefly at night. When fully grown they crawl about to find a protected place in which to pupate. The pupa stage lasts from ten days to two weeks, when the adult emerges. The male moth is generally brown in color and flies about even in the day time. The female is nearly white, with rather inconspicuous cross markings of brown and black, and is larger than the male. The female has a heavy body and does not fly but rests on the trunk or branches of trees, sides of buildings and walls, and in such places she lays her eggs. Figure 83. The adults take no food and live only a short time. ^Journal Economic Entomology, Vol. 7, page 368, 1914. 632 Connecticut Experiment Station Bulletin 375 ^^_> --■"-■■■-:-iiT^,,; - 1 Figure 80. Egg-clusters and pupae on inside of loose hickory bark. Figure 81. Gypsy moth caterpillars. Natural size. The Gypsy Moth 633 It is in the egg stage that most of the time is spent, the eggs being found from August until the following May, a period of nine months. Description Egg. The egg is globular, white or transparent, and slightly more than 1 mm. in diameter. An average of between 400 and 500 eggs are laid together in a cluster and covered with the buff hairs from the body of the moth. The egg-clusters vary greatly in size and shape, but roughly speaking they are oval, about two-thirds as broad as long, and look and feel like a piece of chamois skin. Some large egg-clusters are two inches or more in length, and small ones may be not more than half an inch, y ■ Figure 82. Old pupa skins under fence rail. Natural size. Figure 83. Female laying egg-cluster on bark of tree. Natural size. but in Connecticut the average length is about an inch. Egg-clusters are shown in Figures 80 and 85. Larva. The young larvae resemble the mature ones closely enough so that they may be easily recognized when seen. The fully grown caterpillar has a dusky ground color, finely marked with darker spots, giving it a granular appearance. Sometimes it has a marked brown tint, and some- times it is decidedly gray. There is a lighter stripe along the back with a row of tubercles on each side of it, two on each segment. From the head, the first five pairs of tubercles are blue ; the remaining six pairs are brick red. The colors show more prominently as the larvae approach maturity. There is usually a lighter lateral stripe between the row of tubercles and the spiracles. The ventral surface, legs and pro-legs are 634 Connecticut Experiment Station Bulletin 375 light grayish brown. The head is dark brown marked with yellow. Each segment bears six tubercles arranged in a transverse row, each tubercle bearing a tuft of hairs. The larvae vary from two to three inches in length and are shown on the cover and in Figure 81. Pupa. The pupa is almost naked but is loosely inclosed by a few strands of silk. It is reddish brown in color with a few short, light brown hairs around the spiracles and across the thoracic and abdominal segments. The apical extremity by which it is fastened also bears a tuft of these hairs. The pupae usually occur in clusters in protected places, such as under fence rails near the posts, in crotches of trees, cavities, and similar locations. This stage is shown in Figures 80 and 82. Adult. The female is dirty, creamy white with rather faint, transverse brown markings, and having a wingspread varying between two and two and one-half inches. The abdomen is heavy, cylindrical, and covered with -c^ Figure 84. Female and male gypsy moths. Natural size. buff hairs. The male is smaller and much darker in color. He has a wingspread of about one and one-half inches, with a small and pointed abdomen. The color is brown, varying considerably. Antennae in both sexes are pectinate, narrow and black in the female, broader and light brown in the male. The female is shown in Figure 83, and both sexes in Figure 84. NATURAL ENEMIES Every species of insect has its natural enemies. The gypsy moth has several which are native to this country, but none of them is effective in holding it in check. One of the large ground beetles, Calosoma scrutator Fabr., known as the "searcher" or "caterpillar hunter," was rather com- mon under the burlap bands at Stonington and at Wallingford, and was observed eating the caterpillars. One of these beetles in captivity devoured 137 gypsy caterpillars in 13 days, an average of more than 10 per day. The Gypsy Moth 635 KgK¥ Figure 85. Egg-clusters on trunk of apple tree. 636 Connecticut Experiment Station Bulletin 375 Calosoma calidum and C. frigidum also feed upon the caterpillars, and no doubt other large ground beetles eat them also. Several species of Dipterous parasites have been bred from gypsy caterpillars. In 1910, a caterpillar was observed at Wallingford with Tachinid eggs on its back. This caterpillar pupated in captivity, and from the pupa emerged a large, two-winged fly, Exorista larvarum Linn., (Tachina mella Walk.) (See Figure 87.) The gypsy moth pupa was closely packed with the puparia of the fly, but only one adult emerged. Several other Tachinid flies have been reared from the gypsy moth. Several Hymenopterous or four-winged parasitic flies have been recorded as attacking the gypsy moth. Three or four species of predaceous bugs, called "soldier bugs," are known to attack and kill the caterpillars. Though upwards of 40 species of birds have been observed feeding upon the gypsy moth in its different stages, only a few species are useful in destroying the pest. Among these are the cuckoos, oriole, robin, catbird, blue jay, crow, chipping sparrow, chickadee and vireos. A wilt disease which has been known for several years and which may be indigenous to this country, kills many caterpillars, but is more com- mon where over-population exists or the food supply is depleted. As mentioned above, all the native natural enemies occurring in New England have so far demonstrated their inability to control or appre- ciably to check the gypsy moth. IMPORTED PARASITES As has been stated, in Europe the gypsy moth is not such a destructive pest as in the United States, and probably is held in check by natural enemies. Beginning in 1905, the State of Massachusetts, in cooperation with the Federal Bureau of Entomology, sought to import some of the parasites and predaceous insects from abroad as an aid in controlling the pest in the United States. Dr. L. O. Howard, then Chief of the Bureau of Entomology at Washington, made several trips to Europe and enlisted the services of all the leading entomologists in countries where the gypsy moth occurs. Japan was visited for the same purpose. Consequently, parasitized material was gathered in enormous quantities and sent to the Gypsy Moth Laboratory at Melrose Highlands, Mass., where the parasites were reared, segregated and studied. Many species were found to be hyperparasites and had to be destroyed. The more promising primary parasites were reared in large numbers and were liberated in situations favorable for their development. This work has been continued ever since by the Federal Bureau of Entomology. Altogether, more than three dozen species of parasites and predaceous insects have been introduced to check the gypsy moth and the brown-tail moth. Some of these insects were never recovered after they were liber- ated and some eked out a feeble existence. On the other hand, several species became established, multiplied rapidly and have successfully passed a number of New England winters. Colonies of several of these species have been liberated in Connecticut. The Gypsy Moth 637 Among the most important of the introduced natural enemies is a large, purplish, iridescent ground beetle, Calosoma sycophanta Linn., shown jn Figure 86. This beetle comes from Europe, and in both its adult and larval stages feeds upon the caterpillars and pupae of the gypsy moth. Colonies were liberated in Stonington in 1914, and in Thompson in 1915. In May, 1915, Mr. Harry L. Johnson took a specimen near his house in South Meriden, at least 40 miles distant from the nearest point of liberation. Collections and observations made at various times and places during the past 20 years indicate that this beetle is present in Connecticut and each year kills a certain percentage of the laryae and pupae of the gypsy moth. Two species of Diptera or two-winged flies from Europe are effective parasites. Compsilura concinnata Meig. attacks the large caterpillars and [■ /'