BULLETIN No. 286. FEBRUARY, 1907. ^ GENEVA, N. Y. THE POPLAR AND WILLOW BORER. (CryptorhyncTuis lapatM L.) W. J. SCHOENE. PUBLISHED BY THE STATION. BOAKD OF CONTROL. Governor Charles E. Hughes, Albany. Commissioner Charles A. Wieting, Albany. Stephen H. Hammond, Geneva. Lyman P. Haviland, Camden. Edgar G. Dusenbury, Portville. Thomas B. Wilson, Halls Corners. Milo H. Olin, Perry. Irving Rouse, Rochester. Alfred G. Lewis, Geneva. OFFICERS OF THE BOARD. StephenJH. Hammond, William O\'Hanlon, President. Secretary and Treasurer. EXECUTIVE COMMITTEE. Stephen H.JEammond, Lyman P. Haviland, Thomas B. Wilson. STATION STAFF. Whitman H. Jordan, Sc.D., Director. George W. Churchill, Frank H. Hall, B.S., Agriculturist and Superin- . Editor and Librarian. Undent of Labor. Percival J. Parrott, M.A., William P. Wheeler, Entomologist. First Assistant (Animal Harold E. Hodgkiss, B.S.; Industry). William J. Schoene, B.Agr., Fred C. Stewart, M.S., Botanist. Assistant Entomologists. G. Talbot French, B.S., Ulysses P. Hedrick, M.S., Assistant Botanist. Horticulturist. Lucius L. Van Slyke, PhD., Nathaniel O. Booth, B.Agr., Chemist. Richard Wellington, B.S., Ernest L. Baker, B.S., Assistant Horticulturists. Alfred W. Bosworth, B.S., Orrin M. Taylor, Anton R. Rose, B.S., Foreman in Horticulture. Morgan P. Sweeney, A.B., *F. Atwood Sirrine, M.S., Assistant Chemists. Special Agent. Harry A. Harding, M.S., Frank E. Newton, Bacteriologist Jennie Terwilliger, Martin J. Prucha, Ph.B., Willard F. Patchin, James Wilson, B.S., T Stenographers. Assistant Bacteriologists. Adin H. Horton, George A. Smith, Dairy Expert. Computer and Mailing Clerk. Julia H. Hoey, Junior Clerk. Address all correspondence, not to individual members of the staff, but to the New York Agricultural Experiment Station, Geneva, N. Y. The Bulletins published by the Station will be sent free to any farmer applying for them. *Riverhead,N Y. BULLETIN No. 286. THE POPLAR AND WILLOW BORER. (Cryptorhynchus lapatM L.) W. J. SCHOENE. SUMMARY, This bulletin deals with the poplar and willow borer, an^| imported beetle, which is causing extensive injuries to nursery stock and basket willows, and threatens ornamental poplars and willows. This species has one brood a year. Egg-laying occurs during August and September, and from eighteen to twenty days are required for the eggs to hatch. The larval stage lasts till the following July when pupation occurs. The pupal period occupies about two weeks and the beetles commence to appear about July 15. From this date they may be found until the middle of October. To avoid injuries by the beetle, new plantations of poplar and willow should not be planted near old blocks. In plantings subject to slight attacks, the borer may be controlled by cutting out and destroying in June the parts affected with the grubs. The numbers of the insect will be reduced by burning all branches and trees broken by the wind or otherwise injured and rendered unsalable. Observations have been made of the feeding habits of the beetles which show that they do not discriminate between sprayed and unsprayed plants, and that beetles feeding upon sprayed plants succumb in three or four days. It is believed that nurserymen could avoid important injuries by this insect by spraying during July with bordeaux mixture containing an arsenical poison. Experiments are now being conducted to determine the value of this treatment. INTRODUCTION. Atterution has been called tio the work of the* poplar borer by complaints, from a number of nurserymen in Western New York, of the extensive and continued injuries sustained im the growing of poplars and willows. In the year 1902 some blocks of poplars and willows near Rochester were so badly injured by this insect that some of the growers contemplated abandoning their culture. Since that time the annual loss in many nurseries has not been less than 10 per ct. of the trees and occasionally the entire planting hiais been ruined. In miany localities the native willows along (swamp®, stream\'s \'and canals laire badly attacked, the trees often being so severely affected) that miany of them will ultimately die as a result of the injury. The same is true of certain species of willows\' planted for ornamental purposes. On account of the growing importance of this insect, an investigation was und\'ertaken to determiine its habits with special reference to discovering means for its control in nursery plantations\'. HISTOKIOAL. GENERAL. The beetle was described by LimmaeTis in 1763 in his "Systema Naturae/\' and mention is also made of this species in Turton\'s Ldnmaeu®.1 Kaltenbach2 states that the adult feecftsi upon the dock, Rumex hydrolapathum. Later Prof. Schwagerichen3 states that im the year 1844, -the larvae appeared in the young aiders in the Saxon Oberl\'ausitz. In) 1863, Westwood reported a serious outbreak of the larvae of this cuireulioi aimong tihe cultivated willows in the County of Essex, England. Batzeburg in Ms " Waldverderbnissi,"4 under the heading " Erlanrutsiselkafer " or alder snout beetle, gives a somewhat detailed account of the life history anidl habits of the insect, including reports from others who have observed its work. He states there is nlo record to show that the beetle has been seen sucking or chewing on the " dock Lapathnm." Forstmeister v. Kamptz observed the work of the insect in 1863! on the black alder, which is very susceptible to the attacks of the beetle. In Brehm\'s " Thierleben "5 Dr. E. L. Taschenberg mentions Gryptorhynchus lapathi as being the omly Eliropeaim represeinltative of a South American genus. Prof. F. M. Webister, in an article entitled " Tne Imported Willow and Poplar Curculio/76 sftaites that there are now sixteen species of this genius inhabiting North America, nortih of Mexico, the majority of them being founfd in the south or southwestern staftes. Taschenberg miakes the S\'tatement th\'at the adult onily becomes injurious through its feeding on the leaves. Dr. Bernard Altum7 states that near Eberswalde upon the Leuenberger Weisen,. an outbreak of G. lapathi was controlled by the lVo\\. II, p. 231, 1806. 2Die Pflanzenfeinde aus der Klasse der Insekten. 3Wiegmann\'s Archiv. n: 337. ^Bd. II, p. 247. 6Bd. IX, p. 152. 1877. QJourn. Columbus Hort. Soc, 16:146-155. 7Forstzoologie: Insekten, Abth. I. 86 cutting out of the affected stems. Dr. Altum also reports that in the district of Schonlanke (Bromberg) & plantation which had given eighty cordisi of wood per acre wats ruined. A similar instance is reported from Weisbaden to the effect that about five acres of white alders were threatened: with destruction. The Danish writer Dr. I. E. V. Boas, in 1888, in an \'article entitled "An attack of the snout>billed Cryptorlvynclms lapathi upon willows " gives a short account of its hiaibits- and life history in Denmark, and also mentions) the dkva&tationi of a plantation of willows, Salix viminalis, grown for the purpose of making hoops. In 1897 Dr. Freiherr von Tubeuf,1 states, in effect that, between Brenner-Post and Fenna, (and also between eastern* Arte and Brenner Bad, districts in Tyrol, Austria, the mountain alders presented a sickly appearanice. Examination proved this was largely due to the work of G. lapathi, land that miany of the tnees were also attacked by a fungusi Yalsa oxystoma Rehm. The injuries by these two agencies) are similar in external appearance. HISTORY OP THE SPECIES IN THE UNITED STATES. Attention was called to the appearance of CryptorlvynchMS lapathi in this country by William Juelich in 1882, who found the insect in the northern part of New York City.2 Five years later the willows near West Bergen, N. J., were discovered to be infested, and in 1891 Dr. J. B. Smith reported that in New Jersey willows were being killed by this insect. The beetle was found in injurious1 numbers\' at Melrose, Mass., in 1895 by Dr. C. H. Fernald. The presence of this iusect in the willows about Boston and other towns in Eastern Maissachusetts had been known for many years. During the following year the beetle was found at Buffalo, N. Y., by Ottomar Beinecke; and in 1901 Mr. A. F. Burgess collected one sipecimen near the city of iTwo enemies of the Alpine alder, Alnus viridis D. C. Forstl. Naturw. Ztschr., 1.1892. 2Entomologica Americana, 3 : 123. 87 Ajshtabula, Ohio. In 1903 the rnisect was found] in! two nurseries in the State of Wisconsin by Mr. Christian Flies, the State nursery inspector1 and in 1904 Prof. F. L. Washburn reported that he had received specimens of C. lapathi from North Dakota where it had been found upon poplars that had been imported into that state from a New York nursery.2 ECONOMIC IMPORTANCE. THE BEETLE A NURSERY AND A SHADE TREE PEST. The poplars, willows and alders, while not counted among our most valuable or most beautiful trees, serve useful purposes and are well worthy of preservation. They claim our attention not only for their quick growing qualities anid econiomic value, but also for the mative beauty possessed) by many of the species. Indeed certain schemes of landiscape dieconatiom would be incomplete without some of the more attractive kinds. The native willows perform ani important function as holdler® of the soil along the margins of Lakes and streams; the poplars on (account of their hardiness and rapid growth axe inwaluJable as shade trees in newly settled suburbs; and1 int Western New York the growing of the basket willow is an( important industry. In Europe this insect has been long recognized as an injurious pest upon alders and willows, and1 its work and\' life history have been a fruitful source of much discussion by Gtermjan zoologists. The beetle is reported to be destructive in England, Germany, Austria and\' Demmark. There are many inlstae/ces on record of injury to the basket willow and to the aldiers alomg the streams anjd in the forest, and mjore especially to the plantations of willows anid] alders cultivated for commercial purposes, whidh have often been destroyed. From New Jersey, Dr. J. B. Smith reported) that " C. lapathi was spreading &nd was dointg serious injury to willows. Nearly TOs. Agrl. Expt. Sta. Ann. Rpt., 21: 275. 1904. 2Ninth Annual Report of the State Entomologist of Minnesota, p. 115. 88 all the clumps of willows near Newark and Arlinigtoni had been destroyed, and some fancy and gardto trees had been killed."1 Another interesting and somewhat similar account of injury by the insect was reported in 1899 by Mr. A. H. Kirkland from hisi observations of the behavior of this species in Miassachusietts. In Wimthrop, Bevere, and other shore townis in the eastern p&rt of the Staite, the land is somewhat marshy, and the Balm of Gilead poplar, being the indigenous tree that thrives best, is largely planted in the streets amd yardsi foin islh&ide purposes. The branches are weakened by the borinig of tihe larva (and are broken down by the ice storms amdJ winds. At present there is hardly a sound BaJlm of Gilead poplar in the localities men^ tioned. Mr. Kirkland also states that the work of this beetle caused similar injuries! to the poplars in the larger nurseries of eastern Massachusetts, and that nurserymen were thinking of abandoning the growth of poplars and] willows. Another observer states,2 " So abundant is the pest and so extensive its ravages, that it is rarely possible to find a good healthy plant aimon\'g the shrubby willows about Boston." Dm C. H. and H. T. Fernald, entomologists of the Massachusetts Experiment Station,, reported in 18933 that for several years C. lapatM has been present in great abund&nice. The injuries which it causes to willows, p\'oplans arid simjilar soft-wooded trees* are frequently serious; and\' it is now almost impossible to raise i±Lese tree$ in some localities, thus greatly reducing their vialue for planting a® holdiers of the soil in isuch places\' as sandiy beaches. The diisseminationi of this insect in the State of New York has\' been1 easy and rapid, because of t!he great number of lakes, canals, and small streams that are everywhere bordered with willows. The abundance of these trees aids in the propagation of the ispecies and undoubtedly serves as a means of distribution. The insect spreads not only to ithe native willows along the Wan. EnL, 23: 221. 2J. G. Jack. Gard. and Forest, 10: 394. 1897. 8Mass. (Hatch) Agrl. Expt. Sta. Rpt, 16: 108. 1903. 89 waterway® but alsio to the ornamental willows in the cities1 and to the cultivated poplars and willows in the nurseries. The insect has now become well established im many localities and. the industry of growing poplars and willows1 is seriously threatened, as well as the usefulness and beauty of trees already mature. FOOD PLANTS. The beetle attacks practically ajll of the poplars, willows and alders, for there are very few species that escape injury. Mr. J. G. Jack reports) thiat the beetle has proved destructive to almioist all species of willow anidi all the cultivated poplars grown in the Arnold Arboretum. It has been found boring in the (Stems of aid nlative willows with the exception of a few mountain or very slender stemmed species which are too small to afford the borers sufficient sustenance. Of the foreign willows which niake l\'arge trees1, such species as the white willow, crack willow and laurel-leaved willow, are more or less attacked, though not so liable to injury as the Babylonian weeping willow. The beetle ihiasi been rarely found in small plants of two species of birch, the dwarf birch, Betula pumila, and the red or river birch, B. nigra. The plants in the followirug list are mentioned by German writers as being subject to the attacks of C, lapathi in Europe: Alpine alder, Alnus viridis D. C, white alder, A. incana Willd., black aider, A. glutinosa Willd., purple willow, 8alix ptirpurea L., osier willow, 8. viminalis L., 8, triandra^ Kilmarnock willow, 8. caprea L., white poplar, Populus all)a L., and Rumex hydro-lapatlviim L. The species\' mentionied as food plants1 in this country are: White willow, 8. alba L., crack willow, 8. fragilis L., weeping willow, 8. babylonica Tourn., dwarf birch, Betula pumila L., red or river birch, B. nigra L., Balm of Gilead, Populus lalsami-fera L. var. candicans Gray, Carolina poplar, P. monilifera Ait., and silver-leaf poplar, P. alba L. var. bolleana. The trees that 90 hlave been observed to sustain injuries in this immediate locality are P. monilifera Ait., 8. lucida Muhl., 8. caprea L., 8. cordata Muhl., $. sericea Marsh., $. alba L., amid 8. amygdaloides Anders. These latter were kindly determined by Prof. W. W. Kowlee of Cornell University. LIFE STAGES AND HABITS OF THE INSECT. THE EGG STAGE. Description of egg.—The egg is of a white color turning to & pale yellow when several days old. The shell is thin and fragile, the surface being ismooth and slightly viscous. The sh&pe is elongated oval, obtusely rounded at the ends, oftentimes determined by the shape of the cavity. The longer axis isi 1.1 mm. and the shorter axis .8 mm. in length. Parts of the plant selected for oviposition.—Oviposition occurs in the corky portion® of the wwd, near a bud1 or branch, or in the overgrowth® caused1 by pruning. A cut or break in the bark is a favorite place. When the infestation is marked, eggs can be readily found in \'the callosatieisi caused by injuries of this beetle in previous y£ars. The egg period.—The egg stage Lasts eighteen! to twenlty days. This was determined as foOojvs: A number of beetles\' were permitted to feed upon\' and to oviposit for one dlay in an uninfested cutting from the stem of a nursery poplar. This operation was repeated on succeeding days, fresh wood being used each time. T!he beetles were then- excluded, the cuttings being kept in moist saind under cover to prevent reinfestation. After remaining for fifteen or more days, the entire bark was carefully examined, to aiscertain the number and condition of the eggs deposited in the respective cuttings. The following is the result: 91 Table I.—Time of Incubation of Egg of C. lapathi. Interval Cutting Date of Date of between oviposi- Number Condition in which the eggs were found No. oviposi-tion. examination. tion\'and examina- of eg?s. on examination of the bark. tion. Sept. Oct. Days. 1 13 4 21 6 Eggs hatched and larvae be- ginning to feed. 2 14 3 19 2 Eggs about ready to hatch. Egg just hatched. 3 15 4 19 1 4 16 4 18 2 Eggs hatching. 5 18 9 21 2 Eggs hatched and larvae be- ginning to feed. 6 19 4 15 4 Eggs nearly ready to hatch. DESCRIPTION OP THE LARVA AND ITS GROWTH. Larva, Sept. 22, 1905.—When newly hatched], the terra is a soft fleshy grub destitute of feet and bearing a number of very fine hairs. It is 1.6 mm. long and .6 mm. thick at the broadest points, and .4 mm. at the caudal extremity. It isi somewhat shining \'and of a paile yellow color, being whitish towaird the caud\'al: extremity. The head isi light brown and1 the moiuth-parts are dJark brown, the tips of the mandibles and! maxillae being black. The bod\'y is nearly cylindrical in form, tapering a little behind and swollen at the anterior extremity. Larva, April 19, 1906.—At this time the larva has much the eiame appearance as the newly hatched form, except that it is larger, beinig 4.5 mm. in length. It is> more cylindrical, the abdominial segments being slightly swollen1. The latter have a pale brown color with a pinkish tint. Larva, May 19.—The appearance of the larva is the same as the younger stages. Some of the individuals begin to show a slight variation in size. The length ranges from 5 mm. to 6 mm. . i . - ¦\' i i , !¦ ¦! \' ( •! : Larva, June 12.—The larvae show greater variation in size than was noted upon previous observations. Some members of 92 the brood have apparently ceased to grow, while others hiave miaide a rapid growth. The larvae vary in length from 5 mm. to 11 mm.? the average lenigtih being about 8.5 mm. The larger specimens have begun to bore in the heart wood and in most cases have made a channel about one-half inch long. Larva, June 21.—At this time the larvae show still greater range in size, the length varying from 12.5 mm. in the larger specimens to 5 mm. in the smaller specimens. The largest larvae were ready to pupate. HABITS OP THE LARVA. Most of usually white, and larger both in. length and thickness. In opening the channels, a few splinters or chips can always be found; but when the larva is ready to pupate, the channel is packed for the full length, with the exception of the pupal chamber at the upper end. After filling the channel with chips and making the pup>al chamber, the larva trams* itself head! downward, in which position! the pupa will be found. DESCRIPTION OP THE PUPA. The pupa is about one-fourth of \'an inch long, being somewhat stout and of a pale yellow color. The head, rostrum, and other parts of the bbdy, have a number of small tubercles, most of which bear curved brown hairs. The antennal case is nearly parallel with anid slightly overlap® the femur of the foreleg. The wing cases are partly covered by the first two pairs of legs and in turn almost cover the third pair. The tip of the abdomen is provided with a pair of short strong inward-curving hooks. THE LENGTH OF THE\' PUPAL STAGE. In the vicinity of Geneva, most of the larvae pupate some time during July, as is. shown\' by the following observations. In an examination of some twenty larval channels, m\'ade July 8, one adult, two pupae \'and) fifteen larvae were found. In another examination, of some larval channels on July 12, four adults, four pupae and ten larvae were found. While there were manly adults\' in the larval channels up to the latter dlate, none had emerged. The appearance of the trees on July 30 seemted to indicate that practically all of the beetles1 had emerged. The pupal stage lasts from ten to sixteen days. In one instance, a larva ready to pupate was kept under observation. Pupation occurred during July 13 and the adiult emerged July 27, the period being fourteen days. 94 A DESCRIPTION OF THE BEETLE. The body of the beetle varies from one-third to three-eighths of an inch in length. The general color is a dull black, though the rear third of the wimg covers\', the basal half of the front thighs, and! the ventral part of the prothorax, are covered with white scales. The other portions of the body are covered with black scales interspersed with a few white scales. A few jet black tufts of erect bristles or scales are found upon the wing covers and thorax. When the wing covers axe magnified, each is plainly pitted in ten. longitudinal rows, the thorax also being minutely, though irregularly, punctured\'. The umder1 side of the abdomen anld the legs aire black, being marked here and there by white sicales which are especially numerous on the femora, giving the latter a slightly banded appearance. The head) anid proibosscis are black in color. There is a very marked groove in the sterna which lies between the first and extends to the middle of the second coxal oavitiesi. If the beetle is mot active, the proboscis is contracted into this groove. When handled the beetle frequently emits) la squeakinig noise, Which is evidently made by rubbing the parts of the thorax together. HABITS OP THE ADULT. The adult belongs to the same family as the well known plum curculio anld has somewhat similar habits. When) moving about the beetle does not run, but walks with a slow, steady lumbering motion. The beetle does not fly when disturbed but will drop to the ground1 with limbs and snout contracted, or if on the top sid£ of a branch, will roll over on its* side and to the ground. No beetles have been observed to puncture the leaves. HABITS OP THE FEMALE DURING OVIPOSITION. The female usually eats thirty to forty minutes in making a cavity to coniceal the egg. She then reverses herself anid stands still with ovipositor thrust deep in the opening for thirty second\'s 95 or a minute. The abdomen is then worked up and down as if the egg were being packed in. The whole operation requires two or three minutes. The position is again reversed and the female works the packing with snout and \'antenna for several minutes until apparently satisfied, when sihe moves off in search of another place in which to deposit an1 egg. THE NUMBER OF EGGS OVIPOSITED BY ONE FEMALE. Some observations were m^die in 1905 and 1906 to determine the number of eggs deposited by adult females. When the investigation of the life history of this insect was taken up, in the latter part of August, 1905, practically all the beetlesi of that year\'s brood hiaid emerged from the larval channels. It Was therefore too late to obtain beetles that summer to determine the capacity for egg laying, and know with certainty that no eggs had been deposited. However, some observations were madfe upon beetles that hiaid been captured in a poplar plantation, and; it is thought that simce the beetles continue to emerge for several weeks after the first appearance of the adults, at least some of the beetles haid not begun to oviposit. The details of the observations are as follows: A pair of beetles while copulating were confined in a separate breeding cage, in which bad been planted cuttings about an- inch in diameter that had been made from the stem of a two or three year old nursery poplar to serve as food amid for purposesi of oviposition. After the beetles had fed upon and oviposited in the cuttings for several days, the punctures were dissected with the aid of a lentsi, the eggs not being counted) until they were seen. Observations were made on ten pairs of beetles lasting from Sept. 6 to Oct. 11. The examinations for the eggs in the bark were made at irregular intervals. The egg laying record of the insects is as follows: 96 Table II.—Number of Eggs Deposited by Female , C. lapathi. Insects. Sept. 6 Sept. 7 Sept. 8 Sept. 9 Sept. 11 Sept. 13 Sept. 15 Sept. 18 Sept. 21 Sept. 25 Oct. 11 Total A B .2 2 3 1 5 4 1 3 1 6 8 CSI 25 14 1 C D 1 1 2 1 3 8 5 1 20 4 1 1 E F 2 1 1 2 2 7 6 4 2 7 6 2 3 5 23 G 1 3 2 4 10 H I 2 5 4 1 1 2 3 4 1 4 14 15 1 2 J 1 1 5 4 11 The average number of eggs dieposited by the tern females\' is 16.3, and the greatest number deposited by one individual is 27. An effort was made in 1906 to repeat these observations, upon beetles that had emerged in breeding cages. Many beetles were secured from the wood of some badly infested poplars and willows. A week or ten days after emerging some of the beetle® began to copul\'ate and a n-umber of pairs were isolated. But for some unaccountable reasiom the beetles were short-lived and very few eggs were deposited. FEEDING HABITS OF THE ADULT. The -adult is a voracious eater and obtain® subsistence by puncturing the bark and feeding on the cambium layer. For the first week or ten days after emerging the beetle feeds extensively upon the tender bark of one yeiar old branches!, then copulation takes plaice, after which, the beetles are more often found on the older parts of the tree. One observation seems to indicate that young bark is a prime necessity. A number of beetles developed in a breeding cage in which there was only the old wood from which they had1 emerged. The beetles did not eat the old barb and manyf appeared dead after three or four days, but revived when* put on a diet of young twigs. This was probably the ripening period for oviposition, as during the first Plate II.—Figs. 1 and 2, Bark Punctured by Adults; Fig. 3, Exudations of Splinters and Exckkmext from Larval Channels; Fig. 4. Bark Removed Showing Gird u.vg by Plate III.—Longitudinal Sections Showing Larval Channels of Poplar Weevil. > 05 PL. o a Q W P W 03 H I Plate VI.—Native Willows Injured by Poplar Weevil. r 97 week or ten days after emerging no eggs are deposited. When the beetles arc ovipositing they are more of ten found puncturing the bark of two to four year old wood, and if at this time they are given twigs and small branches of one year old wood exclusively for food, they will riddle the bark with punctures but will not oviposit in the bark. In several instances similar to this the eggs have been deposited on the floor or walls of the breeding cage. No eggs have been detected in the bark of one year old wood. This apparent, distinction shown by the beetle between one year and two year bark is brought out strongly in one of the methods of growing poplars in the nursery, which is as follows: A cutting of one year wood is put in the ground. This is allowed to root and one bud to grow. After one year\'s growth the shoot and tap root are pruned and the stock replanted. At the end of another year it is called a one year old tree, though it may have six or eight inches of two year wood above ground. These one year trees are often infested but the point where the eggs are inserted will invariably be in the two year old wood. According to nurserymen, this pruning and replanting is done to give the tree a better root system. DISTANCE THE BEETLES TRAVEL TO FIND NEW PASTURES. In infested localities the beetles seem to be present everywhere upon willows and poplars, and it is evident that they occasionally migrate or are scattered by some means. However, none have ever been observed in the act of migration. The beetles have perfect wings but in the observations of two summers none have been seen flying. In a grove composed mostly of poplars and willows, isome of which were badly infested with this beetle, a lantern trap was placed on the nights of October 4th and 5th, 1905, and\' again for eleven nights during August, 190G. The catch of insects in each instance was large, both in variety and numbers, but included no C. lapathi. Some observations that are of interest in this connection were made in one of the nurseries 98 belonging to Mr. H. E. Merrill of Geneva. There are four blocks of poplars in a line east and west, each about one hundred yard® apart. The west xand east blocks are the youngest, one being one year old, and the other, cuttings; and though frequently inspected no beetles were found on either, But the central blocks, one two years old and the other three years old, were each badly infested. During the summer of 1906, in order to learn more of the migratory habits of the beetle, thirty-five specimens were caught in a nrursery poplar block and marked so that they could be recognized. These marked beetles were then liberated at a distance of fifty yards from the block in which they were captured. At intervals of several days all the neighboring poplars were carefully examined, and more than four times the original number of beetles were captured, but none of the marked beetles were collected. While these observations are not conclusive, yet it is believed from the behavior of the beetle® that they do not naturally travel far and\' that they rarely migrate from an. abundant food supply. EXPERIMENTS WITH POISON SPRAYS FOR THE CONTROL OF THE PEST. The adult is an external feeder and obtains subsistence by puncturing the baric,—The great number of punctures made in the bark hy the adult while feeding at once suggested the possibility of using arsenical sprays as a means for the control of the pest in the nursery. In order to learn\' the effect of these sprays upon the beetles, a number of experiments were made, as follows: SPRAYING TESTS OP 1905. Experiment No. 1.—On August 26, 1905, the branch of a poplar tree was sprayed with paris green at the rate of one pound to fifty gallon\'s of water. Three pairs of beetles were then put on the branch, which was covered by mean® of strong mosquito 99 netting. Four days.later some of the beetles were apparently dead and the others were ailing. On September 1, six days later, all the beetles were dead. The bark showed no evidences of injury by the beetles. Experiment No. 2.—On August 29, 1905, the tops of two poplars im a nursery row were headed in and then sprayed with arsenate of lead, using two pounds to fifty gallons of water. Eight pairs of beetles were then placed on each tree, being enclosed by means of large cheesecloth bags. On September 4, six days later, twenty of the thirty-two beetles were dead. The wood had been only slightly pumctured. Experiment No. S.—On September 29, 1905, forty beetles were enclosed in a similar manner as in experiment 2 on two trees that had been sprayed twenty days previously with arsenate of lead1., using two pounds to fifty gallons of water. The greater part of the spray had apparently washed off during the twenty days. On September 29, ten days later, some beetles were dead and all appeared ailing. On October 10, all but one, of the forty beetles were dead. As a check on the preceding experiments, twenty-six beetles, divided into five lots, were confined in bags on unsprayed trees to determine if the confinement itself affected the insects unfavorably. The results are as follows: Table III.—Effects of Confinement of Beetles on Unsprayed Trees. Date beetles were confined in bags. Number of beetles to each lot. Number alive September 23. Number alive October 13. Aug. 26. Aug. 26. Aug. 25. Aug. 25. Aug. 25. 14 2 4 2 4 11 2 4 2 3 The bark in each instance was badly-punctured 100 From the above table it will be seen that on September 23, twentv-nino days after the beetles were confined in bags, twenty-two of the twenty-six beetles were still living. On October 15, fifty days after the beetles were confined, six adults were still living. From these results it is believed that the use of bags to enclose beetles had no appreciable effect upon the health of the insect. SPRAYING TESTS OF 1906. On August 23, 190G, the following experiments were undertaken to corroborate the results of 1905 with the use of poisons for the control of the beetle. A tree was selected that had\' been sprayed thirty-nine days previously (July 14) with bordeaux mixture, containing five pounds of arsenate of lead to fifty gallons of the spray. Most of the application had apparent!}\' washed off during the interval. The larger limbs of the tree were cut back land the tree was enclosed in a strong bag of mosquito netting in which twenty beetles were placed. On the same day another tree was selected from a block of poplars which had been sprayed August G with arsen-ate of lead, using three pounds of the poison to fifty gallons\' of water. During the intervening seventeen days all but a trace of the poison had apparently washed off. This tree was bagged as the preceding one and twenty beetles were also confined. A third tree was chosen from a block of poplars that had mot been sprayed and was covered with mosquito netting to contain twenty beetles, to be used as a check. In three d\'ays the effect of the poison began to show upon the activities of the beetles, for the individuals on the sprayed trees appeared dormant. On September 5, thirteen days after being put on the trees, the contents of the bags were examined. All the beetles, forty in number, on the sprayed trees, were dead. Of the twenty specimens 101 on the check tree, only four were dead. The remaining sixteen were apparently mot affected\' by being eniclosed in the bag of mosquito netting. CONCLUSIONS OF THE EXPERIMENTS WITH POISON. While the experiments with poisoni sprays were conducted according to laboratory methods and the number of beetles involved in the experiments was limited to aibout three hundred, the results are encouraging and indicate that thorough spraying with an arsenical poison of the poplar and willow plantations about July 15, will materially reduce the nuniber of beetles and thereby lessen the number of eggs deposited in the trees. THE EFFECT OF CONTACT SPRAYS UPON THE HIBERNATING LARVAE. A numTber of experiment® have been made to determine the effect of various washes, composed largely of lime, kerosene and arsenical poison in combination. These washes were applied during the winter to learn the effect upon the young larvae. In each case the application had no appreciable effect upon the larvae. DOES POISON REPEL OR DESTROY THE BEETLES? After the spraying and bagging experiments of 1905 were completed, it was evident that enclosing beetles in bags upon trees that had been sprayed with poison resulted in the death of the beetles. It wa® now desirable to ascertain whether the beetles died as a result of poison or of starvation. To determine this-, on August 4th, 1906, forty-five beetles, divided into lots of fifteen individuals, were fed in three glass containers with ani abundance of food. The first container held only sprayed twigs and branches, the second held1 both sprayed and unsprayed twigs, while the third held only unsprayed twigs. The beetles in container two fed upon both sprayed and unsprayed food 102 with apparent relish, showing no discrimination between sprayed and unsprayed bark. On August 11, seven days afterward, of the beetles in containers one and two, only one beetle in each lot was alive, while in container three, holding only unsprayed food, thirteen beetles were alive. NURSERY PRACTICES THAT FAVOR THE BEETLE. In a study of the various methods of growing poplars and willows, a practice has now and then been observed that is favorable to the multiplication of the poplar beetle. It has been learned that in most cases the degree of infestation increases with the age of the popl\'ar and willow blocks. Oftentimes a block of one year or two year trees that is practically free from infestation one year, will in the following season be so badly infested that from twenty-five to fifty per ct. of the trees will be unfit for sale. For this reason nurserymen should, as far as is practicable, dispose of the stock when it is not more than two or three years of age. When a tree becomes so badly injured by the beetles that it is unsalable, it should be taken out and burned, as the chances for its recovery are small, and such trees serve as a breeding place for the beetle. The same practice should be pursued with infested native willows that are frequently allowed to grow in swampy places or along canals or streams adjacent to nurseries. Any brush or injured trees taken from the nursery blocks should be burned. On several occasions brush in nurseries has been found to contain adult beetles ready to emerge. A special instance was noted as follows: Several one year old trees were found in a nursery brush pile with the appearance of having been there a week or more. A number of these that had been broken off by the wind as a result of the girdling habit of the beetle, were put in a dry place and examined two weeks later. Of the larval .channels that were 103 examined, a number of the beetles had emerged, some were still in the channel ready to escape, and of thirty larvae present in the channels, all but three reached the adult stage. DIRECTIONS FOR PREVENTION OF INJURY AND CONTROL OF BEETLES. From observations that have been made, it is believed that planting young blocks- of trees adjacent to old plantations facilitates the spread of the beetles, and their injurious work. Whenever practicable, young trees should not be grown near old infested blocks. When a few trees or a plantation is slightly infested, the insect can be effectually controlled by cutting out and burning the infested parts in June, before the beetles emerge. The presenice of the larvae in the wood is1 indicated by the appearance of sawdust and excremental particles, and the exudation of sap at the external opening of the larval channel. Also much benefit will be derived by destroying by fire all branches and trees broken by the wind or otherwise injured, as they are likely to be infested. Plate II, fig. 3. Poplar and willow blocks grown in localities\' where the beetle is abundant should be sprayed during the last two weeks in July with bordeaux mixture, containing three pounds of lead arsenate to fifty gallons of the mixture. This is advised experimentally, as the tests in the nurseries to determine the value of this treatment are not as yet completed. The trees should be thoroughly sprayed so that all parts of the bark, including that of the simall branches, are well coated with the poison. The total cost of this treatment when applied to two year old nursery trees in our experiments, was approximately one-fourth of a cent per tree. The experiments indicate that if the treatment is properly applied it will control the poplar weevil. This spray also protects the tree from many other insect and fumgus enemies. 104 ( If willows or poplars planted for Windbreak®, or screens, or holders of the soil, should become so badly injured aiS to impair, thedr beauty, it is advisable to dig out amd burn the infested trees during the winter or spring, and to replant with some other kind of a tree. For this purpose, Mr. A. H. Kirkland of Massachusetts, recommends the silver maple, Acer dasycarpum, or its variety weirii^ either of, which are said to make a good ^growth in damp localities.