GIFT OF FORESTRY PAMPHLETS PROTECTION Vol. II -- Insects Report on the causes of destruction of evergreen forests in northern New England and Hew York. The Larch Saw-Ply Worm. From Rep't of TJ. S. Dep't of Agriculture, 1883. The Shade-Tree Insect Problem. By A. H. Xirkland Report of Mass. Board of Agriculture. 1901. A Serious Injury to Hickory Trees by the Hickory Bark Borer. An Enemy of Poplars and Willows. Summarized by F. H. Hall from Bulletin by W, J. Schoene. Bull. 286, N. Y. Agri. Experiment Station. ^Insect Injuries to Hardwood Forest Trees. By A. D. Hopkins. Reprint from Yearbook of Dept. of Agriculture for 1903. Three Insect Enemies of Shade Trees. By L. 0* Howard. Farmers1 Bulletin No. 99. Injuries to Forests and Forest Products by Roundheaded Borers. By J. L. Webb. From Yearbook of Department of Agriculture for 1910 Insect Injuries to Forest Products. By A. D. Hopkins. Reprint from Yearbook of Dept. of Agriculture for 1904. The Gipsy Moth and the Brown-Tail Moth, with suggestions for their control. By A. F. Burgess. Farmers1 Bulletin 564. rThe Brown-Tail Moth. and How to Control It. By L. 0. Howard. Farmers' Bulletin No. E64. The Gipsy Moth and How to Control It. By L. 0. Howard. Farmers' Bulletin 275. Danger of General Spread of the Gipsy and Brown- Tail Moths through Imported Nursery Stock. Farmers1 Bulletin No. 453. The Protection of Shade Trees. 24th Report Conn. Agri. Exp. Station. 1900. Insect Enemies of the Pine in the Black Hills Forest Reserve. By A. D. Hopkins. Bull. No. 32 of the Division of Entomology. IlOt T-CS M^ Lib. Forestry • noijojj"! Je»t> lo seacso srl t no $ , • 8 .U lo . nrro v.i^-Vv^ rioiAl a •Sbt ,e 'q •H .A »rft .1001 •e'trjcM^'jf'tgA 'to o^Bo£l .asa!1.- 'io ^"toq .rtaroff .ev/olli 3-iB • eao .v, .v1 «K .m »f .Y •!•! .1 .cie??t7 ^-aerro^ boov/Jbt^r« ct ^xr^fil ^ tnitq .fcfir-tqo .€ ^. -4» /v Tr\ O*v I; r ' ' * 5 f -- '• »^ t 0 l:o '(oc -^ .oM *^« ;^ *3I ivtrtcO o-* T^oH fia-s .?.VS flf.teII0E PROTECTION Vol. II — Insects (Gonfd) Insect Injuries to the Wood of Living Trees. By A. D. Hopkins. Circular No. 126 of the Bureau of Entomology. The Elm Leaf-Beetle. Hew Hampshire College and Experiment Station. Press Bulletin No. 34. Tent Caterpillars. By W. C. OVKane. 35 Wireworms and White Grubs. Extension Circular No 8. By W. C. O'Kane. N. H. College and Exp. Station. Cutworms. Extension Circular No. 7. By W. C. O'Xane, II. H. College and Experiment Sta. The Spiny Elm Caterpillar. By Clarence M. Weed. Bulletin 67. N. .H. Agri. Exp. Station. The Forest Tent Caterpillar, by Clarence M. Weed. Bulletin 64. N. H. Agri. Exp. Station. 301958 ft f no 0 «« gnJt .ovj . l' " . •8/ , , yl37 :;^Mj the tool more easily wielded than if the might- were more distaut>#em the hand. The form of the can is found to be preferably that of a double cone or double pyramid. At its top is a can- screw opening for inserting the powder and closing it securely from wetness. The blast spout passes radially against the inside of the basal cone. The internal relations of the blast to the powder will be better explained by observing Fig. 2, which is a sectional view longitudinally through the parts. The tube, e r, inside the can, has a slot in its side, or sides, and about midway in its passage is a shut-off device, j, where this is set, partially closing the tubular passage; only a part of the blast going through direct, while the rest is crowded out to grind away the powder exposed by the slot passage. The more of the blast thus crowded out, the more of the powder will be fed to, and carried away by, the blast. One, two, or more slots or rows of holes of size and shape to suit may be thus made whereby the blast can act upon the powder in the base of the can. Other views of the same device, with an extension pipe, having a crooked discharge end, appear in Figs. 4 and 5. The lettering has the foregoing explanation so far as it corresponds ; but j indicates the upper or movable face of the bellows, 0 a gauze cover over its incurrent valve, i is the long extension pipe, with a crook, and s its discharge. The long pipe enables the poison to be freed at a safe distance from the operator, and the crook allows it to be easily applied either in an upward or a hor- izontal direction into the plant. Other crooks desirable for some purposes are shown in the extension pipe as seen in Fig. 3. These blowers work with little effort and do very satisfactory work. A tool very similar in shape, but for blowing liquid spray, is repre- sented in Figs. 6 and 7. The bellows is the same as that explained above. The blast pipe, /i, £, r, i, s, is connected with a separate part of the res- ervoir, p, for the poisoned liquid, and a can screw-cap, ?/, is found con- venient for this purpose. When the receptacle is removed by unscrewing it, the small feed-tube, x'y. and the^blast-pressure orifices, by whicbithe blast-pressure in the tube is communicated into the Teservoir and ypon the liquid therein, except that which is in the feed-tube and to be ejected by said pressure, to squirt liquid through the feed-pipe into the blast-pipe, are exposed to be of easy access in case of choking of the passages, or if it is desired to readjust their alterable capacity to feed a greater or less quantity of liquid to the blast. The peculiar form of the poison-can, p, with the feed-tube terminating in its basal apex permits a greater range of tilting of the same without interfering with the supply to the feed-tube, even if the liquid is low. But the construc- tion is such that the apparatus feeds when inverted or when in any other position, and in all positions the feeding is by virtue of the blast- pressure, through an inlet from one part of the blast-pipe where the pressure is greatest to the interior of the receptacle and upon the liquid therein, to eject it into another part of the blast-pipe where the pressure is less. The small can is at times furnished with an automatic supply of liquid from a larger tight reservoir, carried knapsack-fashion upon the back or otherwise, and having an excurrent tube conected with the inlet, 7, of the smaller receptacle. Such a larger receptacle is repre- sented upon the back of a person in Plate V, Fig. 1. An extension tube, ij is shown, and this may terminate in a reatomizing nozzle similar to the nozzles represented in Figs. 2 and 3, or the simpler form here figured which is made by closing the end of the tube and making a side perforation, s, at a short distance back from the end wall. By side pei 138 RE'pORT/oi1 S^kfi^COMMISSTONER OF AGRICULTURE. anotlier "rftbfe bf'constriictiofr'the foregoing nozzles are made to dis- charge the atomized spray in the direction of the main axis of the blast- pipe, which is sometimes desirable, as in applying the poison to trees or in directing it horizontally or downwards. For these purposes the extension -tube may be removed entirely from its juncture, r, and with such a short discharge-pipe spray may be thrown immediately there- from without reatomizing, yet a much finer quality of mist is produced by adding one of the reatomizing nozzles thereto. Again, the machine can be used by substituting a person's breathing apparatus for the bellows. In this case, as in Plate IY, Fig. 8, a blow-pipe and mouth- piece, o, should be added, that the mouth may be far from the poison. This is the cheaper form and may be employed by careful persons. The other parts of Fig. 8 are the same as already explained. Finally, for similar purposes a small squirting apparatus, pictured in Plate V, Figs. 1-5, may be described. It consists of a small telescope- pump having the internal structure of the stirrer-pump elsewhere de- scribed. The cylinder, c, is held by one hand, and the hollow piston-rod, x, by the other. The piston may be held steady while the cylinder is reciprocated back and forth upon it. Being a double-acting pump, a constant pressure and stream is applied. It draws the fluid from a knapsack reservoir, fc, or other receptacle, through the suction-hose, fe, which is joined to the pump cylinder at c. The valve, which occurred in the base of the pump already described, is here inserted in the suc- tion-hose, and by means of the hose is held in connection with the pump. Also in this case the fluid is ejected from the tubular piston- rod through its extension-pipe, a?, u, and the nozzle, s, which is the same as those already referred to. The extension-pipe may be forked, as in Figs. 4 and 5, to apply two or more jets of spray, or it may be entirely removed when desired. Also the pump is well adapted for extinguish- ing fires or squirting into trees, &c., while it will supply itself by suction from a bucket or any other suitable source. REPORT ON THE CAUSES OF DESTRUCTION OF EVER- GREEN FORESTS IN NORTHERN NEW ENGLAND AND NEW YORK. BY A. S. PACKARD, JR., Special agent o/ the Division. THE LAECH SAW-FLY WOEM. (Nematus erichsonii Hartig.) Order HYMENOPTERA ; family TENTHREDINIDJE. [Plate III, Fig. 1, and Plate XIII, Figs. 1, la, 2, 3, 4.] HISTORY OF ITS RAVAGES. In Bulletin 7 of the United States Entomological Commission we enumerated all the insects known to affect or in any way to prey upon the larch or hackmatack. There were none then known to abound upon or to seriously injure this tree, which has heretofore been supposed to be as free as even the hemlock from insect pests. The hackmatack, as is well known, is one of the most important lumber trees in Maine, as it REPORT OF THE ENTOMOLOGIST. 139 sends down a single large root, which grows laterally, forming a bend at right angles to the trunk, so that it is used for u knees " in building vessels, the smaller trees being used for the same purpose in boat- building. The larch grows in wet swamps, or standing water, where the spruce or hemlock as well as pines would not flourish, hence its growth en- hances the value of extensive swampy tracts in Maine, where the water often stands all summer, even through the severest droughts. Its devastation* in Maine. — Our attention was first called to this insect late in August, 1882, and we iirst saw the effects of its ravages at Bruns- wick, Me., where it had partly or entirely stripped the hackmatacks in a very wet swamp on the banks of the Audroscpggin Kiver, on the farm of Hon. C. J. Oilman, who called our attention to the ravages which had been committed earlier in the season. On examining the growth in company with him, we found that most of the trees, both large ones, G to 10 inches in diameter, and small saplings, 6 to 15 feet in height, had been attacked ; some of the trees were stripped, others partially so, while others had wholly escaped. The trees in the middle of the swamp appeared to have suffered most, while the smaller ones on the edge or on higher land were less injured. By jarring the trees a few young, half-grown worms of the second brood which had not yet undergone their last molt, and a single fully- grown larva were collected, while the cocoons from which the saw-flies had escaped earlier in the season were found lying upon the ground or in the moss under the trees. No cocoons with the pupa within, or any other fully-grown worms, were to be found, On the same day (August 30) we examined a noble larch on Mr. Gil- man's ground, which had been nearly killed, as he informs us, by these or similar worms. On September 6 we found that the hackmatacks in cold, boggy, wet land on the crown of Eocky Hill, near Brunswick, had suffered more than elsewhere. Many of the trees were wholly or partially defoliated. According to Mr. Simpson, the injury was here done "about haying time," July, 1881, but the worms had been at work in June and July of the present year. The trees at the time of my visit (September 6) were putting out a new set of leaves on the terminal shoots, the needles or leaflets being from one-third to one-half an inch in length. We also noticed from the railroad train in going from Brunswick to Boston, about the middle of September, that the hackmatacks had been stripped near Portland and Sacoj no trees being observed west of Saco, along the line of the Eastern Eailroad. Our attention, however, had previously been called to this insect by its ravages near Augusta, Me., where it first, perhaps, attracted general attention. The following notice appeared in the Daily Kennebec Journal for Julv 25, 1882: A white worm about three-fourths of an inch long is destroying the foliage of tlie hackmatack and fir trees in certain sections in this vicinity. The trees appear all bare and brown, as though scorched by fire. On applying for specimens and further information to the editors, we received the following note from Mr. W. A. Neweomb, of the Journal, under date of July 31 : I send you to-day some of those worms that are eating the hackmatack trees. I could not find any of the large, full-grown worms, and I think they have gone into the chrysalis state. These that I send are just hatched out, and were all the speci- nu'iis I could I'md. 140 REPORT OP THE COMMISSIONER OF AGRICULTURE. Mr. Newcomb afterwards (August 21) sent me the fully-grown worms of this brood which were then at work on the trees. The following correspondence and extracts will give an idea of the extent of the ravages of this worm in Maine. The "juniper" is evi- dently a local name for the hackmatack. Another destructive pest lias put in its appearance in tlie shape of a green worm. It preys on the juniper trees. All the juniper trees in the swamps, and the shade trees, look as though fire had scorched them ; the entire foliage is eaten in a few days by millions of these worms. — Dover Corr. Bangor Commercial, July 28, 1882. FOXCROFT, August 17, 1882. Your card to the Commercial is before me. The worms which destroyed the juniper foliage came like a shower, and lasted about a week ; they eat the trees clean, and departed all at once, no one knows where or when. I have tried to find one to-day, but could not. The worms were green, smooth, about three-fourths of an inch long, clustered together on a branch, and they ate continually, I should think, by the quick work they did in stripping the trees. No juniper escaped destruction. The lower limbs of some trees were left untouched. C. HILL. We are especially obliged to Charles G. Atkins, esq., Fish Commis- sioner, and who traveled extensively during the last summer, for infor- mation and specimens. He writes as follows : MANCHESTER, ME., August 25, 1882. The editor of the Kennebec Journal wrote me that he had sent you one batch of hackmatack worms, and was about to send you another. Doubtless you have all you need. I did not come upon specimens until too late, though now that I have once found them, I marvel that the affected trees did not sooner attract my attention. They are all about here. I have just returned from a trip to Grand Lake Stream, Washington County, and will give you the results of my observations on hackmatack insects. From Grand Lake Stream to Princeton, and thence to Forest Station, by stage, a distance of 40 miles, the hackmatacks (there called juniper} had been attacked by some insect that had shorn off the foliage of the upper part of each large tree. In all that distance I did not see a dozen trees less than 25 feet high that had been touched, but of those of 30 feet and upward in height 90 per cent, or more had been attacked at the top and denuded8^ almost completely) down on an average, say 8 feet or 10 feet from the top. The terminal shoots of the main stem and branches did not appear to have been eaten off", but the side whorls of leaves were mostly gone. In some cases the outer extremities of large limbs below the region generally denuded had been attacked near their extremities. There were no worms to be seen on the trees. I climbed one tree and searched it carefully, but found nothing. On descend- ing, however, I found a larva crawling on my coat sleeve, a greenish slate color, some three-fourths of an inch long, with black head, which I send you in vial. In Hinkley Township I noticed some sphinx larvae on hackmatack tips, and inclose one. I sup- pose it was feeding, but did not verify supposition. From Forest to Bangor, wherever I saw large hackmatacks they had been gener- ally denuded to a greater extent than on the first part of the route, and the work was worse as I approached Bangor, and a smaller class of trees had been attacked than in Washington County. I ascertained by inquiry that the devastations extended eastward as far as Orland in that direction, beyond which I know nothing. From Bangor westward the depredations everywhere appeared (I came by rail to Keadfield), and on going to a remote part of my farm where hackmatacks grow, I find they have generally suffered, but I notice here that trees under 10 feet in height have generally escaped. Here I find that the dormant buds on the sides of the twigs have begun to push out a new growth, which is now one-fourth of an inch long. I find lots of empty pupa cases in the turf under one of the trees, and send some in a vial j possibly some of them may contain pupae. No worms to be seen now. Mr. A. P. Buck, of Foxcroft (postal messenger on E. & N. A. Eailroad) told me that they were at work in his vicinity, and had committed more havoc than anywhere on the E. & N. A. Eailroad, and even small trees had been completely stripped. Hon. Z. A. Gilbert, of East Turner (post-office), (his farm is in the northwest cor- ner of Greene and southwest corner of Leeds, or near the Androscoggin River), says the hackmatack worms have been operating in his vicinity for three years. After the first attack the trees all leafed out. After the second some died, and now, after the third, many appear likely to die. REPORT OF THE ENTOMOLOGIST. 141 I showed the larva I got in Washington County to both Buck and Gilbert, and they thought it might be the same that they had seen in their sections, except that Mr. G. thought his worms were more positively green in color. He said it was characteristic of them to work first at the top of the tree, as I had observed in Washington County. Mr. G. is secretary Maine Board of Agriculture. It looks as though our hackmatack forests might be totally destroyed by this insect. I inclose some clippings from the Home Farm referring to this insect. I also send you some terminal shoots of white pine, in which you may find living specimens of a borer in three stages ; I suppose it is Pissodes strobi. In one grove|of white pine on my farm it has taken 10 per cent, of the leading shoots. CHARLES G. ATKINS. GRAND LAKE STREAM, ME., February 27, 1883. In September, after receiving your request to send the cocoons to Providence, I ex- amined them (hurriedly), and finding some defective ones concluded the whole lot was worthless. I went out once afterwards to get some more, but did not find them. I now think the cocoons I had were mostly sound in September or October, and possibly may be now, but my keeping them dry and generally warm all this time may have de- stroyed their vitality. Such as they are I mail them to you herewith. I learned from E. C. Smith, of New Sharon, Franklin County, that the worm in question infested the hackmatacks in that town last year. Also from Z. A. Gilbert, Secretary Board Agriculture, that in August, 1882, he made a trip to Aroostook County, and, my inquiries having called his attention to the matter, he looked for indications of the presence of the hackmatack worm and saw none. He was acquainted with them at home in Androscoggin County. Very truly yours, CHAS. G. ATKINS. The hackmatacks in the region near to and south and southeast of the Kangeley lakes, and near Phillips, Me., were also defoliated in the early part of the summer of 1882, as we have been informed by Dr. H. G. Miller, of Providence, E. I., who went to the lakes in August. In the summer of 1883, we found the females laying eggs, and young hatched out late in June and early in July, from Brunswick to Phillips, about Lake Umbagog, especially at Errol, N. H., and by the middle and last of July the trees were nearly stripped of their leaves throughout Maine, and many trees were fatally injured. Its ravages in Neio Hampshire. — In Franconia, as we have been in- formed by Prof. W. W. Bailey, of Brown University, Providence, the hack- matacks were stripped of their leaves about the middle of July, 1882 ; the smaller trees suffering most. The trees were observed by him August 10. We noticed at Errol, on Umbagog Lake, numerous trees which had been killed by the worms, and from the number of worms seen July 4th do not doubt that many trees in that section were at least partly stripped a week or two later. Its appearance, in Massachusetts. — We learn from Mr. Andrew Nichols that the European larches were, in 1882, attacked by " worms " in the vicinity of Danvers, Mass. In July, 1883, the worms abounded on the same trees, specimens being sent us by Mr. Nichols. We observed worms at work in July, 1883, on the European larch at Lawrence, Mass., and they were also destructive at Danvers. Mass. Prof. C. S. Sargent, di- rector of the Arnold Arboretum, Brookline, Mass., and special agent of the*United States Census, Forestry Division, writes us as follows : I have not heard of any injury to our native hackmatacks. Three or four years ago, however, I noticed that specimens of the European larch in this immediate neigh- borhood were suffering from the attacks of a larva, which I gathered and submitted to Dr. Hagen. I inclose his note upon the subject. A copy of Professor Hagen's letter is here inserted : [MUSEUM OF COMPARATIVE ZOOLOGY, Cambridge, Mass., July 7, 1881. The larrae belong to the Teuthredinidae (Hymenoptera), to Nematus erichsonii Hart, the Canadian Entomologist, Vol. XIII, No. 2, p. 37, 1881, I have given a short no- ufol 142 REPORT OF THE COMMISSIONER OF AGRICULTURE. tice concerning the same, sent last year from the Arboretum. The museum is very rich in Nematus, but does not possess this species, which is very rare in Europe, ami has only twice before 1840 been observed to be very obnoxious to the larch in Hol- stein by Tischbein andintheHarzby Saxesen. Ratzeburg, in his last work, remarked only that it is rare, but may prove to be rather obnoxious. The species is, so far as I know, not described among the United States species, surely not under its original name. ,The following note by Dr. Hagen, extracted from the Canadian Ento- ogist, is the one referred to in the foregoing letter : Nemaius ericlisonii on Larix enropcea. — A large number of larvas, very young to nearly full-grown, some probably full-grown, were sent living, with the twigs. The larvie agree perfectly with description and figure in Ratzeburg's Forst-Insecten, Tom. Ill, PI. 3, Fig. 4. The species is not represented in the collection here, neither in the larva nor in the imago state. It is not mentioned in Mr. Norton's catalogue of N. Am. Ten- thredinidaj. I have to remark that the larva} of the three other species living in Eu- rope on Larix. viz, Lyda laricis, Nematus soleus, and compressus, from their description, do not agree with those sent to me. I am indebted to the Harvard Arboretum and its director, Mr. Charles S. Sargent, for these specimens. — Canadian Entomologist, Vol. XIII, No. 2, p. 37, 1881. Its appearance in Northern New York. — Mr. George Hunt, of Providence, who is a close observer of plant and insect life, and who annually visits the Adirondack region in the vicinity of Scroon Lake, informs us that about July 25 and early in August the hackmatacks were seen to be entirely defoliated, no leaves being left on the trees by the first of August $ he observed the effects of the worms at Horicon, Warren County, and Scroon Lake, in Essex County, as well as at Pottersville. The region affected^was very extensive, covering many square miles in different swamps. No worms were observed in 1881. He has presented us with some of the worms, which are of full size, and do not differ from Maine specimens. They were fully grown July 28. HISTORY OF THE SPECIES AND ITS HABITS. Notwithstanding the efforts made to rear the larvae of this species last summer, no perfect insects were obtained, the cocoons furnished us by Mr. Atkins having been all parasitized by a species of Pteromalus, a parasite of the hymenopterous family Chalcididse; while of two false caterpillars which spun cocoons, neither had hatched up to the time of writing. On referring to the great work of Eatzeburg on forest insects, the admirable colored figure of the larva of Nematus erielisonii which he gives exactly represents the peculiar style of coloration of our worms ; we had identified it as perhaps this species, or as the young of one rep- resenting it in this country. It appears by the foregoing extracts that Professor Hagen had exam- ined the larva and had identified it as Nematus erichsonii. We are unable to find any differences in the larvae from the figure of the Euro- pean species, and the cocoons are of the size and form as figured by Ratzeburg. A description of the fully grown larva is not given by Ratzeburg. The eggs are described by Ratzeburg (after Tischbein) as about one-half a line (%") long, white, transparent, laid in a row upon and within the young larch shoots. The following is a free translation of his description of the saw-fly, which he calls the large larch saw-fly, and figures in Theil III, PI. HI, Fig 4. 4-5"' long and wings expanding 10-11.'" In sculpturing and coloring so great a simi- larity with N. aeptentrionalis $ that it would be mistaken tor it, were it not for the tarsal REPORT OF THE ENTOMOLOGIST. 143 scoop-like dilatation in latter species; but there is in place of the -wing-band, only a light shade in the largest cubital cell; both the femoral hooks and apophyses are almost clear, tho wing-angle of the prothorax brownish white; the whitish femoral rings arc only clear on the hinder legs, and on the abdomen at. most the four middle rings are reddish-brown. The punctures are finer than in N. septentrionalis, especially on tho scutellnm and on tho rather shining mesosternuin. Eatzeburg states that he himself has not observed this insect, which occurs in Germany and other parts of Europe. It appeared on the larch in the Harz Mountains as well as in the plains of Holstein. The larva?, are social, but do not occur in such thick, crowded clusters as do those of Lophyrtis. The flies make their appearance toward the mid- dle of June. The eggs are laid usually in a single row on the upper end of the young shoots, two or three sometimes being placed together along the shoot. The eggs are inserted in a little slit made by the ovi- positor under the epidermis. They hatch at the end of June and early in July, and the larvcosta; it also sends an angle inwards behind the median vein, and again another angle •outward opposite the inwardly-directed angle. There are often two distinct, costal, whitish dots (sometimes wanting) just before the apex, while the apex itself is brown. There is also a large brown patch in the middle of the wings near the outer edge. There are numerous fine, short, transverse, brown lines dividing the wing into squares •or checks, bordered with brown. The bands and short lines are more or less confluent or separate, varying much in this respect. Some females differ in the umber-brown being bright rust-red, and the clay-blue pale ferruginous brown, while the broad, •median, zigzag band is umber-brown on the edges and bright rust-red in the middle, .and the wing is covered with an irregular network made by the short transverse and -longitudinal dark-brown lines enclosing rust-red or smoky-red patches. Legs, body, and hind wings glistening umber-brown ; tarsi ringed with pale brown. 'The abdomen of the female is very stout ; that of the male ending in a long, distinct, Ihai ry tuft. Described from perfectly fresh specimens, 5 $ ; 8 9 • Length of body 9-10mm j of fore wing 10-12mm; expanse of wings 19-22mm. THE SPBUCB NEMATUS. (Nematus integer Say.) Order HYMENOPTERA; family TENTHREDINID^. [Plate XIII, Figs. 6, 6a, 65, 6c.] Although this insect is not, so far as known, especially destructive to evergreen trees, yet it is common over the Northern States and may at times prove obnoxious. It occurs on the spruce in Maine in the latter part of summer, and feeds separately, not being gregarious as in most 150 REPORT OF THE COMMISSIONER OF AGRICULTURE. species of Lophyrus or the Larch Nematus. It is possible that the fly escapes from the cocoon in the autumn, but as a rule it without doubt passes the winter in the cocoon, the fly making its appearance in the late spring and early part of June, specimens having been found dead in the breeding-box in the middle of May. DESCRIPTION. The larva. — The "body is long, broader than the head ; pale pea-green ; of the color of the leaves of the spruce among which it feeds. The head, is smooth, of the same color as the body, with a dark patch extending upward behind each eye. Body not spotted, but with a dorsal dark green stripe, bordered on each side"with whitish glaucous green. Along the body is a lateral conspicuous broad white stripe, the stripe much scalloped below. Body beneath, and abdominal legs, uniformly green ; thoracic legs pale honey yellow, except at base. Length 17mm. Cocoon. — Of the usual oval cylindrical form ; of a pale horn color, of the usual density, the walls being opaque. Length IS*1"1 ; diameter 4mm. The saie-fly (imago) [2 females]. — Antennas 9-joiuted; flagellurn minutely hirsute, 7-jointed, the two basal joints of flagellum equal in length; head and body dull amber yellow (testaceous) ; eyes black ; ocelli situated in a dark-brown patch ; a black irregularly triangular spot above the insertion of each antenna, being situated in a pit between the eyes and the intier edge of the broad orbits. A single minute trian- gular black spot between the antennae ; clypeus, labrum, and palpi pale dull amber (testaceous), concolorous with the head ; the mandibles dark at tips. Prothorax above not spotted. Mesonotum with three longitudinal, dark, broad stripes ; prajscutum dusky reddish brown, pale on the sides ; on the middle of each half of the scutum a broad blackish band reaching the front edge, but not extending posteriorly behind a point parallel with -the apex of the scutelluin. Behind and be- tween the ends of these dark bands are two small dark spots. Scutelluin on the posterior half dark brown*; the inetascutum is black. Sides of the thorax and beneath pale faded amber (testaceous), with a triangular black spot on the sides of the prothorax below and in front of the wings. Abdomen of the same color as the rest of the body, but on the sides and beneath with a greenish tinge ; above black, especially towards the base, next to the thorax ; the segments above being banded transversely with black on segments 1-8, the bands growing shorter (transversely) behind, until on the 8th segment the dark band is scarcely wider than long ; the black bands extend on each side of the front edge of each segment, forming a point on each side. Under side of nieso- and metathorax a little dusky. Fore and mid die pair of legs testaceous; extreme tips of tibiae and tarsal joints with a very narrow black ring ; last tarsal joint with the pad (pulvillus) and end of claws dark. Hind legs : femora in color testaceous ; tibiae a little dusky, paler towards the femora ; all the tarsal joints equally dusky. Ovipositor at base reddish horn color, tip blackish. Wings with the veins blackish brown ; costal edge paler ; stigma dark testaceous ; 4 subcostal cells, the 1st or innermost 4-sided, subquadrate. Length of antenna 5mm j length of body without antennae 8mm ; length of a fore wing 8mm. NOTE. — This agrees in all respects with Mr. Norton's description of Nematus integer Say, var. a (Trans. Amer. Ent. i, 216). It is recorded from Maine, Massachusetts, Connecticut, New York, Pennsylvania, and Indiana. It thus seems to be a widely distributed species. It is closely allied to Say's JV. vertebratus and to Norton's JV. trili- neatus, but the pale fore and middle tarsi and the greenish tint distinguish it. The description of the larva is taken from Bulletin 7, U. S. Ent. Comm., p. 234, No. 20. THE HEMLOCK GELECHIA. Gelediia abietisella, n. sp. Order LEPIDOPTERA ; family TINEIDJS. [Plate III, Fig. 2; Plate XIII, Figs. 7, 7a, 7&.] During the spring of 1883, the hemlock trees, large and small, in the vicinity of Providence, E. I., were observed to be much disfigured by the attacks of a small Tineid worm, causing sere and dead patches of leaves on the smaller branches and twigs of both large and small trees. REPORT OF THE ENTOMOLOGIST. 151 The small pale-green caterpillars bite off from six to eight leaves, con- structing a broad flat irregular case ; the leaves on being separated from the twig turning red or yellowish, thus forming a conspicuous patch. This rude case is held together with silk, the worm living in a rude silken tube, and feeding upon the inside of the leaves. The length of this tube, within which the little caterpillar finally changes to a chrysalis, is from 8 to 10mm in length. The worms are found from the first of May through the month of June. One changed to a pupa in its tube about the 20-25th of May, and the moth (in confinement) appeared June 1. Other chrysalids were found in the tubes from June 20 to 30, the moths making their appear- ance early in July. The moth is beautifully marked, and probably examples occur through- out the suifcmer. Without doubt the eggs are laid on the twigs or leaves in the summer, and the caterpillars become almost full-fed before the winter, hibernating in their cases, becoming active in the spring. The worms are preyed upon by an ichneumon, the oval cocoon with one pupa which had recently transformed, and another ready to imaginate occur- ring in the cases June 9th. DESCRIPTIVE. The full-grown larva. — Body sleiider, cylindrical, not flattened. Head of the normal form, not modified in shape as in leaf-mining larvae; not so wide as the body, smooth, amber colored. Body tapering slightly towards both ends, pale green, of the same hue as the under side of the leaves of the hemlock. Cervical shield well marked, greenish amber. Each segment is dorsally divided by a transverse suture into two slight folds, on the anterior and larger of which are four dark green piliferous warts arranged in a straight line, and two on the hinder division or fold. There are similar warts on the sides and beneath. Legs 6-f-Bj the thoracic feet are pale, blackish at tip. The four pairs of abdominal legs are concolorous with the body. The supra-anal plate amber-green, with a few long setae, as long as the body is thick. Length Q1**0. Pupa (alive). — In form slender, spindle-shaped, the head considerably narrower than the body, gradually tapering from the thorax to the end of the body; antenna} and wings reaching to the hinder edge of the 5th abdominal segment. End of the abdomen rather blunt and rounded, with a few very fine hairs. Along the side of the abdomen a row of short, thick spinules, one on the side of each segment, none on the back ; a pair of such spines on the under side of the 6th segment. Eyes reddish ; body pale amber, with a greenish tint on the thorax. The two terminal segments darker than the rest of the abdomen, and concolorous with the head. Length, 4-5mm. The moth. — Rich buif-yellow, with rich golden and white scales. Head and thorax white, with a few buif-yellow scales. Palpi buff-yellow, with the basal joint somewhat blackish on the upper edge ; terminal joint long and slender, with two black imperfect rings, the tips acute, white; eyes black. Antennae black, with numerous fine white rings; they scarcely taper to the tip. Fore wings long and narrow, of nearly the same width throughout ; the outer edge much rounded ; the fringe at the outer angle long and dense ; buff-yellow, with white and golden scales ; costa black at base ; beyond are three large, nearly equidistant, long black costal spots more or less connected on the extreme costal edge ; three equidistant black points on the sub- median vein, the first situated opposite a point half way between the two basal costal spots ; the second opposite the end of the second costal spot, and the third op- posite the third costal spot ; the third spot is sublinear and ends on the edge of the wing at the internal angle. On the costal part of the apex of the wing is a curved row of four black spots, the fourth situated at the extreme apex of the wing, and on the outer and hinder edge are two or three minute black dots, between which and the fringe is a white patch, the fringe being also streaked with white. All the black spots are more or less edged on one side with white scales. The fringe on the outer costal half is lead color with minute black scales at the apex of the wing. Below and within, the long silky fringe is much paler. Hind wings very narrow, almost linear at tip, and with the fringe concolorous with the fridge of fore wings below and within the apex. Body and legs pale glistening buff-yellow. Hind tibiae long, with a wide fringe ; first pair of tibial spines twice as long and about one-half as thick as second pair ; the tarsi ringed with black and white. Length of body 5mm ; of fore wing 5mm ; expanse of wings llmm. 152 REPORT OF THE COMMISSIONER OF AGRICULTURE. REPORT OF PROGRESS IN EXPERIMENTS ON SCALE- INSECTS, WITH OTHER PRACTICAL SUGGESTIONS. BY H. G. HUBBARD, Special Agent of the Division. SOAP EMULSIONS. Further experiments with kerosene emulsions prove that various soaps can be readily made to combine with the oil, and that the soap and kerosene emulsions are as effective as those formed with milk. The use of soap materially reduces the cost, except where milk is abundant and cheap, as is very seldom the case in Florida. Common bar soap, soft soap, and whale-oil soap have been tried and found to be almost equally good. Whale-oil soap, when of good quality, may be preferred, as it is stronger, and adds to the insecticidal proper- ties of the emulsion. The following formula is one which has proved in practice useful where a moderate quantity of emulsion is required. It gives a wash of sufficient strength to kill the eggs of the scale-insects commonly found in Florida: KEROSENE AND SOAP EMULSIONS. Formula. Kerosene. 2 gallons = 67 per cent. Common soap or whale-oil soap £ pound ) Qo Water 1 gallon j=33Percent- Seat the solution of soap and add it boiling hot to the kerosene. Churn the mixture by means of a force-pump and spray-nozzle for five or ten minutes. The emulsion, if perfect, forms a cream, which thickens on cooling, and should adhere without oiliness to the surface of glass. Dilute, before using, one part of the emulsion with nine parts of cold water. The above formula gives 3 gallons of emulsion and makes, when diluted, thirty (30) gallons of wash. The percentage of oil can be increased considerably without danger to the plant, and a stronger emulsion may, in fact, be required in coping with some of the Aspidiotus scales, upon which we have had no opportu- nity to experiment. But the amount of kerosene in the emulsion cannot be greatly reduced without weakening too much its power as an insecti- cide. The amount of soap may also be varied, but less than one quarter ot a pound to the gallon of water forms an unstable emulsion. . After another year of experiment and practical experience in the use of kerosene emulsions as a remedy for scale-insects we see no reason to change the opinions expressed in former reports. The distrust of kerosene naturally felt at the outset has in time given place to confidence, and the emulsions are now widely used by orange- growers in Eastern Florida. Many groves treated with kerosene emul- . sions have been under our own observation, and the results have been uniformly beneficial. Want of thoroughness in applying the wash, however, frequently renders repeated applications necessary. The invention and introduction of the cyclone nozzle by the Depart- ment of Agriculture greatly diminishes the labor of applying the liquid to orange trees and insures success with ordinary care and attention, at EXPLA3STA.TION" TO PLATES. PLATE T. C'AliHAGK WORJ1S. (Original.) Fin. 1. Pieris rapee %* FIG. la. Pieris rapie :, , ovipositisg. FIG. 16. Pieris rapcecf FIG. lo. Pieris rapue, larva1 of different stages. FlG. Irf. Pieris rape?, chrysalis. FIG. 2. Pin si a. braiu. Plutella cruciferaruin, larva. FIG. Ga. Flittella cruciferarum, pupa. PLATE II. THE LESSER LOCUST. (From Report I, TJ. S. E. C.) FK;. 1. ('al>jifenns atlitnitt. newly hatched or in first larval stage, from side; Ib, same, while yet pale, from above; lc. aii- tt'una of same. FIG. 2. Second stage ; '_'«, antenna : 2b, thorax, from above- :>. thorax, from side. FIG.:;. Third stajre: ::.'/, ant«-nna; 3fc, thorax, from above: :;<•, thoiax, from si«, antenna; 06, thorax, from above; 5c, thorax, from side; ad, pupal exuvuc, or last skin shed. FIG. 6. Sixth stage, or mature insect; the figure showing a typical male — natural size. FIG. 7. Typical female, with wings expanded— natural 8ize. FIR. 9. Enlarged thorax of mature insect, from above ; (J«, same, from side. FIG. 10. Anal characters of male, from, above; JOrt, same, from side; 10&, same, from behind. Fi<;. 11. Anal characters of female, from side; lla, anal characters of female, irom above. PLATE III. FOREST TREE INSECTS. (Original.) FIG. 1. Xoti.atv.s erichsonii, female (enlarged). FIG. Id. Larch twig denuded by AT. erichsonii. FlG, Iff. \ei)tat'is erichsonii, outline (natural size). FK;.!/>. FlG. lc\ erichsonii, larvae of different ••<'>nii, cocoon. FIG. 2. fielechia abieticida, adiilt (enlarged). !•!•.. •_'KUIXG WlTil 1N6ECTICJDB8. (Original ; W. S. Barnard, del.') FIG. 1. Direct powder blower; bellows, V; hollow handles, It; powder can. /;,- to dis- charge. *•; i'eed adjuster,^; screw-<-aj>.//. FIG. 2. Powder-can iii section; blast tube, er; side slot and feed regulator, oj; body of can, 'i>: screw-cap, >t. FIG. 15. Exterior cieiv of can n:i(h crooked extension < .'U.i'; screw-cap, »/; gaiiuf,/'.- upward discharge, --••. FlG. 4. Bellow*, a.m. and »tfni'•!!/> iff! iliachcrfjp; bellows, /:,- ln-ad,./'; gau/e valve cover, Z; handle, h; fau,y>,- coii]de, or hose, r.- j)ij)e, /,• discharge, ,;. FIG. ~>. Compact beUoiog~c&n arrangement; cau,pp; screw-cap, .'/.- handle, A; valve gauze, Z: liead.j,- discharge pipe, h,e,r,c. FIG. 0. Hand bellotcs Kpraij bloirer ; bellows, ",• ;e. valve, Z; handle, ft; discharge pipe, h ;/ r i s; spray, s; screw -cap couple,.*/; can.p; apex,a;; bases, a n; supj)ly tube, I. FIG. 7. Liquid can in section; blast pipe, ?/; can,/); suction pipe, xp y; blast inlet, ?/; a]>ex, .(•: bases, <• n : su]>ply tube, I. FlG. H. MoUth spray-blotter n-(th direct dischargf: inoulh piece, o ; blast tube, tejs; cou()le. f; screw-cap,;/,- can, p; apex, a1; bases, a ii; supply tube, i. PLATE V. U.VU'S.U'K I't/.ML1 rM»Kl;rtl'RAYI-;R AND Al'l'I-'UTEXAXCES FOR Al'l'LVING I.NSKCTK IUKS. FIG. 1. K-napsc.ck pi'mp undersprai/er iu opera- tion: loops, b b; support can, k: suc- tion hose. /• h <'; ejeotbt-pump, c x; pis- ton u>.l extension, .<••«'«.- to eddy cham- ber J)ox,/,]e, it: siile spray, x. 2. Edd;i chdii-hrr nuzzle, natural si/.e; lace view and sectiou. (Original: W. S. Barnard,^.) FIG. 3. Eddy clmmbcr nozzle, f, for direct dis- charge,. FIG. 4. Trailing pipe fork; its stem pipe, f; y-fork, ii: inside s]>ring rods, a js; flexile joints, ci-: lii'an -plate, or shoe, ee,- uoz- •/.]{' arm-pipes, i i; their swing, m n tit; nozzles, n n. EXPLANATION TO PLATES. PLATE VI. DEVICES FOR UNDERSPRAYIXG TREES WITH IX8KCTICIDES. (Figs. 1 and 2 original ; 3 and 4 from Ann. Kept. Dept. Agr. 1881-2.) FIG. 1. Parts of hose-pole device for spraying trees,- bamboo pole, b b; drip washer, j; hose, h Xf side hook, v; eddy chamber noz- zle, n m; spray, z s. FIG. 2. Metallic hand pipe with diagonal nozzle,- hose, h; metallic pipe, t; diagonal eddy chamber nozzle, n; its removable face, i; spray, *. FIG. 3. Barrel rest or skid; two coupling cleats, 66; two side rests, a a; chamfered con- cave, c c. FIG. 4. Stirrer pump with barrel and mixer funnel in section; funnel, u; its cylindrical sides, g g; funnel base, 1 1; spout, p; (in bung -hole, k), gauze septum, d; barrel, k k; trunnions, i; trunnion eyes, e; wedge, v; lever-fulcrum, /; pump lever, i i; swing of the lever head and piston top, a b C; cylinder packing cap, c; cylinder, q; its swing, x y; stirrer loop or eye, h; stirrer bar, m ?i; rope, w w; bung, r z. FIG. 1. Coal-oil pan, large size. FIG. 2. Coal-oil pan, small size. FIG. 1. The Bobbins Coal-tar pan. FIG. 2. The Flory Locust-Machine, front view— in operation. PLATE VII. (From Ftept. I, TL S. E. C.) FIG. 3. The Anderson Coal-oil contrivance. PLATE VIII. (From Kept. I, U. S. E. C.) FIG. 3. The same, side view of frame. PLATE IX. (From Kept. I, U. S. E. C.) FIG. 1. The Eiley Locust Catcher. PLATE X. CABBAGE WORMS. (Fig. 1 original; 2, 3, 4 after Kiley ; 5 after Harris.) FIG. 1. Pieris monuste; a, larva; b, pupa; c, adult. FIG. 2. Pieris protodice, c?. FIG. 3. Pieris protodice, ?. FIG. 4. Pieris protodice; a, larva; 6, pnpa. FIG. 5. Pieris oleracea; a, larva. PLATE XI. (Figs. 1, 3, 4, 5, and 6 original; 2 alter Riley.) FIG. 1. Phymata erosa; a, dorsal view (enlarged) ; b, side view (enlarged) ; c, front leg (enlarged); d, rostrum (enlarged). FIG. 2. Plusia bragsicce,- a, larva ; 6, pupa; c, moth. FIG. 3. Plutella cruciferarum; a, larva (enlarged ) ; 6, dorsum of a single joint (greatly en- larged) ; c, side view of same ; d, pupa (enlarged) ; e, cocoon (enlarged) ; /, moth (enlarged) ; g, wings of dark va- FIG. 4. Fig. 5. FIG. 6. riety (enlarged) : h, moth at rest (en- larged) : f, creinaster of pupa (greatly enlarged). Pionea rimosalis ; a, larva; 6, pupa; c, moth ; rf, segment of larva (enlarged*. Larva of Plusia brassiere parasitized by Copidosoma trnncatellum. Copidosoma truncateUum (greatly en- larged). PLATE XII. (Figs. 1 and 3 original; 2 after lliley.) Fis. 1. Mamestra chenopodii; a, b, larva; c, pupa; d, moth ; e, wing of same (enlarged) ; /, anal segment of pupa. FIG. 2. C'eramica pictn,- a, larva; 6, moth. FIG. 3. Oaleruca xanthomelcena,- a, eggs; b, larva?; c, adult; e, eggs (enlarged); /, sculp- ture of eggs; (j, larva (enlarged); ft, side view of givatly enlarged segment of larva; i, dorsal view of -same: j, pupa (enlarged) ; k, beetle (enlarged) ; I, portion of elytron of beetle (greatly enlarged). PLATE XIII. (Original; Packard— Gissler, del.) FIG. 1. Nematus erichgonii? head of larva before last molt. FIG. la. Same, full-grown larva. FIG. 2. Maxilla of same, from above; g, galea; lac, lacinia ; palp, palpus. FIG. 3. Same, underside; mx, maxilla; mxp, max- illary palpus; mx', labium; mx'p, labial palpus. FIG. 4. Mandible of same. FIG. 5. Pteromalns parasitic on same. FIG. 6. Nematus integer, head and thorax; psc, praescutum; sc, scutum; scl, scutel- lum. FlG.6a. Same, ovipositor; 9, 10, 9th arid 10th ab- dominal segments; ov, ovipositor; c, cercopod. Flo. 66. Same, wing. FIG. 6c. Same, antenna. FIG. 7. (jfilechia abietisella, larva enlarged (natu- ral size indicated by hair line). FIG. la. Same, head and thoracic, and first abdomi- nal joints more highly magnified. FIG. 76. Same, terminal joints on same scale as last. All the figures magnified. ;p'ort of EntomologistU.S.Dep? of Agriculture, 1883 Plate III LARCH AND SPRUCE INSECTS No. 4.] SHADE-TREE INSECT PROBLEM. 77 THE SHADE-TREE INSECT PROBLEM. I'.V A. II. KIKKLAND, M.S., BOSTON, MASS. The love of nature common to man never finds worthier expression than in the planting of shade trees. We plant orchards that our financial resources may be increased ; we plant shade trees primarily that our environment may be adorned and our inner lives enriched. The limitations of circumstances may restrict our planting to a few specimens of some favorite variety ; or it may be our good fortune to have a part in beautifying streets and public places with trees that will contribute to the enjoyment of thousands to us unknown. In either case we pay homage to nature as manifested under one of her most pleasing forms. What a tribute to the good taste and good sense of past generations are the magnificent elms that adorn the valley of the Con- necticut. These monarchs of the meadow are all around us. Had they voices, what tales could they relate of genera- tions and events whose records have long since passed into history. Beside their ripened age the span of human life seems as but a watch in the night. We approach them with admiration that is akin to reverence. Here they have con- templated the passing centuries ; here they have witnessed the development of a great nation ; and here they still stand, eloquent though silent witnesses of the forefathers' love for the beautiful and thoughtfulness toward posterity. And perhaps it is well for our peace of mind that audible speech has been denied our grand old trees. Had they voices, no doubt they would cry out at the injuries and wanton neglect too often falling to their lot. Their roots, anchored deep in the earth, are severed to make way for curbings or water mains ; their Heaven-seeking tops are butchered to give clear passage to electric wires ; and, what 78 BOARD OF AGRICULTURE. [Pub. Doc. is more common, their foliage is denuded and their vitality sapped by hosts of hungry insects whose ravages might be prevented with a minimum amount of intelligent effort on the part of man. So general is this latter form of injury that tree lovers are being continually brought to face what may be well named ''The shade-tree insect problem." The damage may be slight, and confined to a single valued tree ; or it may be great, and seriously affect the shade trees of an entire com- munity. Under one guise or another the problem recurs with the seasons and apparently in increasing magnitude. It is indeed a problem that may well receive the earnest consideration of this Board, — a body which for half a cen- tury has actively and consistently encouraged every effort making for the better preservation of fruit and shade trees. That damage by insects is increasing seems to be an ac- cepted generalization. Things were not thus in " the good old days," if we are to believe commonly circulated state- ments. Admitting frankly that insect damage is now of more importance than formerly, I would suggest that, in contrasting present with past conditions, due allowance be made for the infirmities of memory and the deficiencies in records. Accounts of insect depredations in the early years of civilization, while relatively scarce, show that injury by these pests has been contemporaneous with the development of agriculture. Considering the slight attention given to natural history in early literature, the sacred writings contain many inter- esting references to insect damage. Of the plagues of Egypt, three were of an entomological nature, — lice, flies and locusts ; while the lament of the prophet Joel, "That which the palmerworm hath left hath the locust eaten ; and that which the locust hath left hath the cankerworm eaten ; and that which the cankerworm hath left hath the caterpillar eaten," may well strike a responsive chord in the hearts of agriculturists of the present day. Three hundred years before Christ, Aristotle described several noxious insects ; while Pliny, writing about 77 A.D., has given lengthy details of insect damage. Theological No. 4.] SHADE-TREE INSECT PROBLEM. 79 writings of the middle ages describe several church trials of the insect pests of that day. Such proceedings were of a most serious and formal nature. The pests were haled (by proxy) before the bar of the church, and, after being found guilty, were subjected to anathemas and maledictions. We may say parenthetically at this point that this unique method of dealing with insect pests has been described at length by M. Laverune in " Cosmos," of Sept. 12, 1897 ; and that in the year of grace 1899 an attempt was made to check the forest tent caterpillar invasion at St. Hilaire, P. Q., by sim- ilar means. Later newspaper reports indicate that the use of Paris green finally proved a more effective remedy. The historic outbreak of the brown-tail moth at Grenoble in 1543 is one of the best authenticated instances of wide- spread damage from caterpillars. The Puritan settlers of Massachusetts early found their attempts at agriculture hindered by the attacks of native insects, and gravely recorded the seasons of 1646 and 1649 as " caterpillar years." Scarcely a century ago Damage by the canker worm in Boston and vicinity led the Massachusetts Society for Pro- moting Agriculture to offer a substantial reward for the best treatise on the insect, and means for preventing its ravages. Between 1860 and 1880 damage by the gypsy moth in the forests of central and southern Russia reached a severity hardly paralleled by any insect depredations previously recorded. I have given some space to the mention of these historical insect depredations, to emphasize the point that in all lands and at all times noxious insects have vexed the labors of the tiller of the soil, and that the present is not an unusual period, so far as damage by insects is concerned. Com- pared with past standards, however, it is an unusual period in the increased attention given to the care of trees. Never before have so many people been interested in the cultiva- tion of trees ; never before have greater efforts been made to disseminate information concerning their proper treat- ment. The care of public shade trees is being made gener- ally a public duty throughout the land. The tree warden 80 BOARD OF AGRICULTURE. [Pub. Doc. act in this State is an encouraging sign of the times, show- ing the drift of popular sentiment. The enhanced value now placed upon shade trees leads naturally to an increased appreciation of the damage wrought by shade-tree insects, — an interest bound to grow with the increasing concentra- tion of population in cities and their suburbs. Of three principal factors directly favoring an increase in insect depredations of shade trees, one of the most impor- tant is the massing throughout large areas of a single species of tree, in accordance with the modern dictum " that every connected street must be planted with a single variety of tree." Insects are more or less critical in matters of diet, the tent caterpillar preferring the wild cherry, the elm- beetle the various species of elm, the brown-tail moth the pear, and so on throughout the list. Where the chosen food plant of a particular insect has been planted in large numbers, there that species finds just the best conditions for its rapid development. The " City of Elms" must be of necessity the city of elm insects. Boston Common gives a more familiar illustration. The older plantings are almost entirely of the American and English elms. The white- marked tussock moth finds in the foliage of the elm food exactly suited to its development ; hence this insect has periodically stripped these elms at least from the days of Harris to the present time, its ravages being ultimately checked by the increase of its parasites. Another factor which has contributed in no small degree to recent outbreaks of shade-tree insects is the superabun- dance of the English sparrow, a seed-eating bird, pugna- cious, filthy in habit, and of but little practical value as a destroyer of insects. This bird thrives best where popula- tion is most dense, and this is just the condition under which shade trees have the hardest struggle for life. Im- mensely prolific, and finding an abundant food supply in the form of offal and refuse, the sparrow has directly or indi- rectly eliminated the native birds which formerly inhabited our city trees and fed upon injurious insects. We need not seek far to find an illustration of the harm wrought by this bird. In Northampton and vicinity the sparrow has largely No. 4.] SIIADK-TREK INSIST PROI5LKM. 81 driven out the native birds. In the farming communities just outside this city damage by the canker worm is now of frequent occurrence. The hilltops to the west, Chesterfield, Huntington and Blandford, for example, are not yet occu- pied by the sparrow. There cuckoos, orioles and warblers nest undisturbed, and there the chickadee, nuthatch and woodpecker ply their trade throughout the year. Although the canker worm breeds in these localities, it is seldom able to develop in numbers sufficient to commit serious harm. Damage by the sparrow along this line is particularly notice- able in the case of insects which are general feeders. Special feeders, insects like the elm-leaf beetle, limited to one or a few food plants, cannot spread beyond a certain area without exhausting their local food supply ; thus they are subject to limitations which eventually confine their activities. On the other hand, general feeders, like the gypsy moth, forest tent caterpillar and web worm, are not restricted to a single or even a few food plants ; hence in their cases man stands in even greater need of the help given by birds and parasites. Add to this the fact that these general feeders are usually hairy, and that hairy caterpillars are seldom eaten by the sparrow, and the damage caused by this bird is seen to be greater than would at first appear. So far as Massachusetts is concerned, the greatest damage to shade trees by insects in recent years has been caused by certain imported pests. These insects, accidentally brought to our shores, usually arrive unattended by the parasites which hold them in check in their native environment. Finding America a land of freedom indeed, they commit depredations by the side of which their ravages in the Old World frequently pale into insignificance. Perhaps as good an illustration as any of this point is found in the case of the San Jos6 scale (Aspidiotus pernici- osm), which, primarily a fruit-tree insect, is becoming a dangerous enemy of shade trees in many localities. Intro- duced into California in the early seventies, it has spread into nearly every State if not every one in the Union, kill- ing nursery stock, fruit trees and even shade trees of good size. Probably no more deadly orchard insect ever found 82 BOARD OF AGRICULTURE. [Pub. Doc. its way to our shores ; yet so comparatively harmless was it in its native environment that we have but just learned au- thoritatively that it hails from northern China. Beyond doubt its increase at home is restricted by certain parasites, and when it was imported to the United States the importa- tion did not include the beneficial agents. Of these imported pests, the one at present of the greatest general importance in Massachusetts " is the European elm- leaf beetle (GaleruceUa luteola, Muell.). This insect has FIG. 1. Different stages of the elm-leaf beetle: a, eggs; 6, larvae; c, adult; e, eggs enlarged; /, sculpture of eggs; g, larva enlarged; ft, side view of greatly enlarged seg- ment of larva; i, dorsal view of same; j, pupa enlarged; k, beetle enlarged; I, portion of wing-cover of beetle greatly enlarged. — From Riley, Report United States Depart- ment of Agriculture, 1883. now established itself in nearly all our cities and larger towns. It has been characteristic of the northward spread of the beetle that its routes of march have been particularly along water courses and the seaboard. One reason for this readily suggests itself. These well-watered localities are the ones in which the elm most freely develops. It divides No. 4.] SHADE-TREE INSECT PROBLEM. 83 honors with the willows and poplars as the characteristic tree of our river valleys and seaboard. This abundance of elms along our streams long ago defined the areas in which the beetle etui breed to the best advantage, and where it will doubtless become a permanent resident. The swarms of beetles which invaded this State from the south by way of the Housatonic and Connecticut valleys have passed north- erlv into southern Vermont and New Hampshire, while lateral swarms have ascended the valleys of the Westfield, Deerfield and Ware rivers. Another invasion of a later date has occurred along the line of the Blackstone River. The beetle has also worked eastward around the coast and ii}) the Merrimac River to Haverhill, Lawrence and Lowell. The main lines of railroads probably have contributed in no small degree to the diffusion of the beetle, which with the approach of cold weather frequently enters freight cars for the purpose of hibernation. Finally, the compact plantings of elms in the centres of our towns and cities have given the insect the best kind of an opportunity to develop as a local pest. The life history of this insect is similar to that of other members of the great family Chrysomelidoe. The beetles hibernate in large numbers in sheltered localities, under roofs, shingles, clapboards and in empty buildings. As soon as the warm weather starts the buds of the elm, these beetles emerge and feed greedily upon the young leaves, which soon become perforated as if by charges of fine shot. After feeding for a week or ten days, egg-laying is com- menced, and by this time the leaves are nearly developed. The beetle feeds and lays alternately over a period of several weeks. Two female beetles observed by Dr. E. P. Felt for four weeks laid respectively 431 and 623 eggs. Because of the similarity, any one familiar with the eggs of the potato beetle will readily recognize those of the insect under dis- cussion. The yellow, spindle-shaped eggs of the elm-leaf beetle are laid in small compact masses on the under surface of the leaf. In a week's time the eggs hatch and the young larvae commence feeding upon the tender foliage. While the damage caused by the feeding of the mature 84 BOARD OF AGRICULTURE. [Pub. Doc. beetle is of considerable importance, it is not to be com- pared with the injury wrought by the larvae. These insects destroy the epidermis, feeding upon the under sides of the leaves. The latter turn brown and soon fall from the tree, sometimes leaving it as bare as in midwinter. When the larvae are full grown they are about one-half an inch in length, light yellow in color, with black markings arranged along the back to form two conspicuous stripes. The ma- ture larvae drop in large numbers from the tips of the over- hanging branches, and pupate in masses in or near sheltered places. A small per cent pupate beneath the bark of the tree, or descend to its base. From these orange-colored pupae in from five to ten days mature beetles emerge and feed upon the foliage. There are two well-defined broods of the insect at Provi- dence and on Cape Cod, and a partial second brood certainly occurs at Springfield. The effect of the repeated defoliation is to sap the vitality of the trees and invite the attacks of other injurious insects, notably bark beetles and borers, and the death of the tree is often the ultimate result. While the spraying of the foliage is a difficult and often an expensive undertaking, it offers the most effective means of combating this insect. The insecticide used should be some form of arsenate of lead, and, if possible, should be thoroughly applied in the spring, when the beetles are feed- ing. It is obvious that, if the hungry hibernating beetles can be destroyed, further damage by the insect will be pre- vented. The general custom, however, is to wait until the foliage has fully developed, and then treat it with a heavy spraying of arsenate of lead. This will destroy the late- feeding beetles, and will remain in an effective condition until after the eggs have hatched and the larvae have com- menced to feed. One thorough spraying should preserve the trees from injury throughout the season, although in the case of the second brood it is sometimes necessary to make an additional spraying late in July or early in August. Since Massachusetts abandoned the work of exterminating the gypsy moth (Porthetria dispar, Linn.), the numbers of this insect have increased to an alarming degree in the east- Elm at Boston defoliated by larvae of elm leaf beetle. No. 4.] SHADE-TREE INSECT PKOBLKM. 85 ern part of the State, and we must now prepare for the time when it will become generally diffused throughout this and adjoining States. For two years it has had an opportunity to multiply unrestricted, and the developments of last sum- mer would lead us to anticipate a repetition of the outbreak of 1888-89 in the near future. Already in many localities in the metropolitan district formidable colonies of the moth have seriously menaced park and shade trees. The Fells reservation of the metropolitan park system is badly in- fested, and most strenuous efforts will be needed in the near future, if one of our most beautiful park areas is to be pre- served intact for the enjoyment of our citizens. The parent moth lays its eggs to the number of five hundred to one thousand, in a yellow, hairy covered mass, on tree trunks, fences, buildings, walls, etc. The eggs hatch early the following May, and the caterpillars swarm abroad in search of food. They devour both buds and leaves, and sometimes even attack the tender bark of the twigs. As soon as the foliage develops they give it their undivided attention, feeding chiefly by day. When about one- third grown their feeding habits change, and the insects seek shelter by day and feed almost entirely by night. The full-grown caterpillar is. sparingly covered with stout hairs, and has a double row of tubercles along the back. On the five anterior segments these tubercles are blue ; on the six posterior, dark red. The caterpillars pupate in masses in any convenient shel- tered locality, particularly at the bases of large branches, and in about a fortnight the moths emerge. The males are yellowish brown, expand about one inch, and fly actively on warm days. The females are somewhat larger than the males, white, sparingly marked with black, and, although FIG. 2. Egg cluster of gypsy moth. 86 BOARD OF AGRICULTURE. [Pub. Doc. provided with well-developed wings, do not fly. After mating, the females at once deposit their eggs, the life cycle of the insect usually being completed by the middle ot Au- gust. As the egg masses are usually laid near the ground, and are conspicuous for some eight or nine months, it is obvious that this season is an excellent time to combat the insect. The spongy egg masses should be saturated with a mixture of creosote oil, containing 15 per cent coal tar in- corporated by the aid of heat. The addition of the tar is not necessary for the destruction of the eggs, but is desirable in order to color the treated nests, thereby distinguishing them from those untreated. In extremely cold weather the mixture thickens, and should be thinned by the addition of turpentine or benzine. Where this work of egg de- struction has been neglected, and the caterpillars allowed to hatch, chief reliance should be laid upon a thorough spraying of the foliage with arsenate of lead as soon as it develops. Advantage should also be taken of the habit of the cater- pillars in seeking shelter, by tying bands of burlap loosely about the trunks of the in- fested trees at a convenient height. These bands should be examined every day, and the caterpillars concealed beneath them destroyed. The chief characteristics of the gypsy moth which make it so serious a pest are its wide range of food plants, feeding, as it does, on all deciduous trees and nearly all conifers ; its relative immunity from attacks by parasites ; and its insid- ious night attacks, whereby entire trees are often defoliated before the presence of the insect in force is suspected. In the attempt to exterminate the gypsy moth the State FIG. 3. Full-grown caterpillar of gypsy moth. Pines, oaks and other trees stripped by the omnivorous cater- pillars of the gypsy moth. Georgetown, July 11, 1899. No. 4.] SHADE-TREE INSECT PROBLEM. 87 of Massachusetts has given the world one of the greatest object lessons in applied entomology. The abandonment of the work by action of the Legislature at a time when the insect was well suppressed has seemed to many a great mis- take. Present indications are pointing in no uncertain way to the ultimate justification of the State work against the moth as conducted by a committee of this Board. The truth will ultimately be established, and we must wait with pa- tience the developments of the near future. It is fortunate that from this great undertaking there have developed improved methods of combating insects, which have a wide application. Thus the original use of ar senate of lead as an insecticide against the gypsy moth has now been extended to the treatment of the elm-leaf beetle and a host of other leaf-eating insects. The improvements in spray- ing apparatus developed in the gypsy moth work have a world- wide usefulness, and al- ready this improved apparatus is now in general use in park work in the larger cities of New England. FIG. 4. Pupa of gypsy moth. The past summer has brought to light a large colony of the gypsy moth at Providence, R. I. From all evidence at hand, it is apparent that the insect was taken to this city by some malicious person, and it is quite possible that other similar colonies may be found elsewhere. In view of this fact, it seems probable that the gypsy moth will now never be exterminated in New England. Property owners in the vicinity of the infested sections should carefully familiarize themselves with the appearance of the various forms of the nioth, in order that incipient in- festations may be dealt with in season. Should official work against this insect be renewed, it would seem desirable to 88 BOARD OF AGRICULTURE. [Pub. Doc. FIG. 5. Male gypsy moth. carefully investigate the parasites preying upon this insect in its native home, although such work was hardly feasible while the State was engaged in the effort to absolutely ex- terminate the moth, as the presence of imported parasites would necessitate the presence of an abundant supply of the host insects. Another European insect re- sponsible for a notable amount of damage and annoyance in east- ern Massachusetts is the rapidly spreading brown-tail moth (Eu- proctis chrysorrhoea, Linn.). This pest first came into prominence in May, 1897, when it was found committing severe depredations on pear trees at Somerville. It seems probable that the insect was brought to this locality on rose bushes imported from Holland or France. This insect has a unique life history, in that its cater- pillars successfully hibernate in a half grown condition in conspicuous webs at the ends of the infested twigs. Leaving these webs as soon as the buds swell in the spring, the tiny caterpillars first consume the buds and later devastate the foliage. By the last of June they have reached their full development, and spin up in loose cocoons on the smaller FIG. 6. Female gypsy moth. branches, on houses, walls and in other sheltered localities. From these cocoons in about three weeks' time the white, brown-tailed moths emerge and fly vigorously by night in search of suitable places in which to deposit their eggs. PLATE I. FIG. 1. FIG. 3. FIG. 2. FIG. 5. FIG. 4. Explanation of Plate I. FIGURES Nos. 1, 2, 4 AND 5 DRAWN FROM NATURE BY J. H. EMERTON. No. 1. — Female brown-tail moth. No. 2. — Winter web of brown-tail moth caterpillars. No. 3. — Pruning shears suitable for removal of winter webs. No. 4. — Brown-tail moth caterpillars, enlarged. No. 5. — Brown-tail moth caterpillars, natural size. No. 4.] SHADE-TREK INSECT PROBLEM. 89 These insects are strongly attracted to light, and great num- bers of them meet their fate in the globes of arc lamps. This same attraction to light, however, has doubtless been the means of spreading the moths from town to town, since it is found that the oldest infestations are found in the cen- tres of towns where the lights are most numerous. The eggs are laid in compact, hair-covered masses, on the under surface of pear and other leaves, and hatch in about three weeks from the date of laying. From 200 to 400 eggs are deposited by each female moth, the rate of increase being somewhat slower than is the case with the gypsy moth. The menu of .the brown-tail moth includes a wide range of ornamental trees, although primarily it must be considered to be a pest of the pear tree. Wherever it is numerous, maples, willows and elms are defoliated to a serious extent. For two years this insect was suppressed by the gypsy moth committee, but with the abandonment of the work of that committee in the spring of 1900 the systematic cam- paign against the brown-tail moth necessarily came to an end. It has been interesting to the writer, living since that date in the infested district, to note the gradual increase and spread of this pest in the vicinity of Boston. Where in the winter of 1899-1900 there were but scattered webs, they may be counted now by the thousand. Not the least important feature of outbreaks of the brown- tail moth is the truly terrible irritation caused by the hairs of the caterpillar whenever they come in contact with human flesh. This irritation is well compared to nettling several degrees intensified, and probably is of a mechanical nature, being produced by the fine, brittle, barbed hairs breaking up in the skin. It is best allayed by the liberal use of vas- eline or sweet oil. Last summer so severe and general was this painful affliction in the Allston and Brighton districts of Boston that the residents of those suburbs petitioned for and received a public hearing at the office of the Boston Board of Health. The nettling of these caterpillars fur- nishes an excellent but painful means of identifying the insect. The brown-tail moth is now known to occur in a territory 90 BOARD OF AGRICULTURE. [Pub. Doc. bounded by Scituate, Brockton, Hudson, Lowell, and Sea- brook, N. H. An isolated colony also occurs at Kittery, Me. As the female moths fly vigorously, this insect spreads much more rapidly than. the gypsy moth, and it seems prob- able that within a short term of years it may occur through- out the entire State of Massachusetts. It is fortunate that the insect is exposed in conspicuous webs throughout the winter, thus making its destruction easy. For the work of cutting off the webs the common form of pruning shears attached to a pole is the most con- venient implement. The webs so collected should be care- fully burned at once. Where this work is thoroughly done, there will be no damage by the brown-tail moth the suc- ceeding year. It is remarkable how quickly and at what small expense these webs may be collected and destroyed by trained men, suitably equipped. In the winter of 1899 the employees of the gypsy moth committee gathered and de- stroyed over 900,000 webs, at a total cost of $9,700. This work of web destruction is the cheapest and most ef- fective method of disposing of the pest ; but if it is neglected until after the caterpillars leave the web in the spring, the infested trees should be thoroughly sprayed with arsenate of lead. It is also necessary sometimes to spray, to protect the trees from the fall brood. This spraying should be done in September, as soon as the small webs are noticed. In the case of pear and other fruit trees this late treatment will result in the poisoning of fruit approaching maturity. How- ever, it is but a choice between two evils, since, if the tree is defoliated, the fruit will fall before it is ripe. On shade trees there is no valid objection to the fall spraying. Turning to our native insects, an important periodic pest of shade trees is the tussock moth ( Orgyia leucostigma, S. and A.). This insect is well known in Boston, Providence and elsewhere, from its severe injuries to elms in certain years. While primarily an elm insect, when numerous it attacks in force the linden, horse chestnut, silver maple, pear and other trees. Its damage is contemporaneous with that of the elm-beetle, and, as it is double-brooded, at least in our river valleys and along the seaboard, it is a shade-tree Xo. 4.] SHADE-TREE INSECT PROBLEM. 91 pest of no mean rank. Fortunately, however, its increase is largely controlled by parasites, which, when the caterpil- lars are numerous, soon gain the ascendency. This accounts for the occurrence of the insect in force only at somewhat extended intervals. The white, froth-covered eggs of this insect are com- mon objects on the trunks of trees chosen as food plants. FIG. 7. Different stages of the tussock moth: o, caterpillar; 6, female pupa; c, male pupa ; rf, male moth ; e, same, wings spread ; /, female moth ; g, female moth on cocoon ; h, egg mass with froth over it; i, cocoons on tree trunk; k, same, showing females and egg masses also ; all slightly enlarged. — From Howard, Yearbook, United States De- partment of Agriculture, 1895. The egg masses are laid by the wingless female moths, — mere spider-like creatures, — in late summer or fall, on the old cocoons, and are covered with a brittle white varnish. The number of eggs laid by a single female ranges from 75 92 BOARD OF AGRICULTURE. [Pub. Doc. to 200, the species being perhaps the least prolific of any we have discussed. The young larvse leave the egg masses late in the spring, after the leaves have developed, feed freely on the foliage, and attain maturity by mid-summer. Their characteristic markings are two plumes of hair directed for- ward on either side of the head and a similar plume point- ing backward from the posterior end of the body, together with a row of short, dense brushes down the upper surface of the body. The caterpillars drop freely from the branches when disturbed, and are carried from place to place by teams and pedestrians. When full grown the larvae spin up in loose, yellow cocoons on the trunks of trees, along fences and in other suitable sheltered places. In two weeks the moths emerge and deposit eggs for a second brood, which is frequently more injurious than the first brood. The moths from this last brood continue to appear until freezing weather sets in. Thus at Somerville, Mass., November 2 of the pres- ent year, the writer found belated female moths of this spe- cies still engaged in the work of egg laying. This insect is controlled easily by spraying with arsenical poisons or by the destruction of the egg masses in the fall, winter and spring. Crude creosote oil, uncolored, gives perhaps the best means of killing the eggs. It should be applied by means of a sponge or brush, as in the case of the gypsy moth egg clusters. Where an invasion of the tussock moth has commenced, non -infested trees may be kept free from the swarming caterpillars by the use of stocky bands of raupenleim, bodlime, tar, tree ink, or even cotton bat- ting. On small trees the caterpillars may be jarred off, and the trees banded to prevent reinfestation. The destruction of the cocoons before the moths have emerged is not ad- vised, because of the large numbers of beneficial parasites that breed therein. The fall web worm (Hyphantria cunea, Dr.) probably is one of the most general feeders of our insect fauna. Ap- pearing in late summer, it spins its unsightly webs on the tips of branches of almost every kind of a fruit or deciduous shade tree, at once distinguishing itself from the tent cater- pillar, with which it is commonly confounded. The latter Elms at Boston defoliated by caterpillars of Tussock moth, 1895. No.. 4.] SHADE-TREE IXSKCT PROBLKM. 1)3 insect appears only in the spring, and always places its webs in the forks of the branches. The butternut, ash, oak and elm have to pay tribute to the web worm, while the maples, lin- dens and horse chestnuts are almost equal sufferers. A ride through the State in August or Sep- tember will show that the pest has little preference in the matter of lo- calities or food plants. The fact that it appears so late in the summer is of advantage to the trees, since at that season the ef- fect of defoliation is not as injurious as when it occurs at an earlier date ; still, the webs are unsightly, the in- sect annoying, and the injury to the tree of sufficient importance to necessitate remedial measures. Farther south, where the insect is double-brooded, its ravages have an increased im- portance. In this State the moths emerge from their cocoons in July, and lay upwards of 400 eggs in a cluster on the under surface of the leaves. The young larvae at once begin spin- ning a web, which includes the near-by foliage, and often extends by the close of the feeding season over an entire branch. These webs doubtless serve as some protection from parasites, although on the other hand, they are the best kind of sign-boards for the guidance of cuckoos, orioles and other birds that consume hairy caterpillars. When full FIG. 8. Fall web worm, moths and cocoons, natural size. — From Howard, Yearbook, United States Depart- ment of Agriculture, 1895. 94 BOARD OF AGRICULTURE. [Pub. Doc. grown the caterpillars are one and one-half to two inches in length, with yellowish, longitudinal markings, and clothed with grayish hairs. They wander about on walks and fences in search of places to pupate, and in this latitude often find shelter beneath loose rubbish on the surface of the ground ; otherwise, the cocoons are placed at the base of the tree or on fences near the ground. Pupation takes place in Sep- tember, and the white moths do not emerge until the fol- lowing July. As already pointed out, the web worm is extensively preyed upon by birds. It is also parasitized by various ichneumon flies. In eastern Massachusetts it is often confounded with the brown-tail moth, whose webs, however, are much smaller and more compact, and whose caterpillars feed outside of the web, returning to it for shelter only. A common practice among farmers is to burn the webs by means of a torch. If this is done as soon as the insects ap- pear, no strong objection can be raised against the practice, as the large branches will not be injured, as is often the case where tent caterpillar webs are burned in this way. A better practice is to spray thoroughly with arsenate of lead as soon as the first webs are noticed. The poisoned foliage will be drawn into the web, and the caterpillars destroyed. And right here we may well emphasize a unique property of arsenate of lead. This insecticide adheres in a notable degree to the foliage, and trees that have been thoroughly and heavily sprayed with it in the spring will be exempt from damage by the web worm in the fall. Some years ago the writer sprayed part of a row of pear trees, about May 15, to destroy the brown-tail moth. Va- rious strengths of arsenate of lead were used, and it was found that trees sprayed with this insecticide at the rate of 3 or more pounds to 100 gallons of water were completely exempt from damage by the web worm the following Au- gust. Lower proportions of the poison did not give satis- factory results, while the trees in the row that were not sprayed were badly injured by the web worm. As the trees sprayed were in the middle of the row, the result of the treatment was unmistakable. No. 4.] SHADE-TREE INSECT PROBLEM. 95 Willows and poplars are much in demand in planting schemes for damp localities, or in places where rapid growth is desired. As trees of this class are so well adapted for such purposes, it is most unfortunate that they are becoming more and more subject to damage by the imported willow weevil (Cryptorhynchus lapctthi^ Linn.). This small snout beetle of the great family of weevils has been known for generations in Europe as a pest of the basket willow and of alder plantations. Its food plants there include about all the willows, poplars, many alders and a few birches. It occurs from southern France up into the highest mountains of Switzerland, where it breeds in the green alder. Doubt- less it was brought to this country in nursery stock ; cer- tainly its general occurrence in the nurseries in this State would give force to this opinion. It has now spread at least from Brooklyn to Portland and westward to Buffalo and points in Ohio. The mature beetle is of a dark-brown color, with a con- spicuous white marking at the posterior part of the body, and with smaller white markings on the anterior part of the wing covers. With its long snout it drills holes into the bark just beneath the leaf scars, and inserts its eggs, from one to four in a place, each in a separate chamber, which is afterwards closed with bark dust. This egg laying, as the writer has observed it, takes place late in the summer ; but in nearly every case the eggs hatch and the larvae feed in the bark for a few weeks before hibernating. The insects at this time are so minute in size that they can be found only by diligent search. With the coming of spring, however, they extend their burrows in the bark, breaking through the surface at frequent intervals, and then in about a fortnight sink into the sapwood and finally to the heart of the tree. The growth of the white, yellow-headed larva is something phenomenal, especially in young trees. By the first week in July the larvae are fully grown, and carefully enlarge their burrows downward to the surface of the bark, throw- ing out large quantities of white chips, which are an excel- lent indication of the presence of the insect. The sap which oozes from the burrows is also a characteristic sign of the 96 BOARD OF AGRICULTURE. [Pub. Doc. insect's work. Having drilled its burrow to a uniform diam- eter, the insect ascends to the upper end, packs itself se- curely in an elliptical chamber, and pupates. In 1897 the writer collected a large number of infested sticks of poplar, and examined them daily from June 30 to July 31. In a single stick, one and one-half inches in diameter and two feet long, he found 57 larvae. Some of these sticks were split open each day, and on July 3 and 4 about all the larvse were found to have pupated. By July 22, mature beetles were found in the wood, although emerging did not take place until about July 31. This would give us about eigh- teen days as the length of the pupal stage. The beetles appear all through the months of August and September, and, after feeding for some weeks upon the ten- der petioles, deposit eggs for the brood of the following season. In young, rapidly growing trees, with an abun- dance of tender wood, the development of the insect is as detailed ; in older trees a part of the beetles do not emerge until the second spring. This gives us the straggling im- agoes that have so confused students of the life history of this insect. This pest is not amenable to treatment by spraying, so far as at present known. The best method of treating it is to dig out the young borers in the early spring, when they are still at work in the bark, where their black burrows can be detected by careful observation. Trees infested with this insect are weakened, and are easily broken down by ice storms. This insect gives us another illustration of the folly of planting only a single variety of shade tree. The silver maple, the three-thorned accacia and the elm make good growth in localities where poplars and willows are most grown for shade or ornament, and are not subject to attack by this weevil. It is difficult, in a paper of this kind, to select those in- sects that are most injurious without excluding species of at least considerable local importance. Should all important shade-tree insects of the State be considered fully, the next winter meeting of the Board would find us not far removed from the meadow city. The writer believes that the insects No, 4.] SHADE-TREE INSECT PROBLEM. 97 discussed are the ones most commonly troublesome to the shade trees of this State ; and, with their treatment well un- derstood, it will be easy to apply similar methods in the cases of allied pests. It will be noticed that, of the insects in the previous list, all but one are amenable to treatment by spraying, although in the case of the brown-tail moth by far the cheapest method is to destroy the winter webs by hand. This leads us to consider the best insecticides for spraying, and the means of applying them. There are certain simple tests by which the merits of an insecticide for use against leaf-eating insects may be determined : it must kill the insects ; it must not injure the foliage ; it must adhere to the leaves for a reason- able length of time ; and its price must not be prohibitive . Three compounds of arsenic fall within these specifica- tions, viz., London purple, Paris green and arsenate of lead. Of these, London purple, while effective and cheap, is open to the objection of being a by-product, and therefore of ir- regular chemical composition. Some samples contain a large percentage of soluble arsenic, and therefore cause serious injury to the leaves. It settles rapidly in the spraying tank, and requires considerable stirring. It does not ad- here well to the foliage, and where its application is followed by repeated rains, a notable burning of the leaves usually occurs. In the market the price of London purple ranges from 15 to 20 cents per pound ; and, as but 1 or 1J- pounds are used to 100 gallons of water, it is by far the cheapest arsenical insecticide. While its use is not advised, should it be adopted, it is well to add 2 or 3 pounds of fresh-slaked lime for every pound of the insecticide. This will convert the soluble arsenic into arsenite of lime, and thereby lessen the burning effect. Paris green for years has been the mainstay in work against leaf-eating insects. It is probably the quickest in its action of the three insecticides mentioned. • Where all the insects it is desired to destroy have hatched and are feed- ing, and good weather prevails, there is no better insecticide for use than Paris green. But these conditions are almost impossible of attainment in the damp, changeable climate 98 BOARD OF AGRICULTURE. [Pub. Doc. of New England. Again, Paris green has a high specific gravity, and requires constant stirring. An overdose will clear the foliage from trees even quicker than the insects it may be desired to destroy. At present prices for copper, Paris green retails at from 18 to 30 cents per pound, and a good article can hardly be bought for less than 25 cents per pound. Paris green is ap- plied at the rate of 1 pound to 100 or 150 gallons of water, and should be used with double the amount of lime, to in- sure a better distribution and to neutralize any uncombined arsenic. With a strictly pure Paris green the addition of lime is not necessary. Since the discovery of the value of arsenate of lead as an insecticide by the chemist to the gypsy moth committee, it has come into increasing use as a remedy for shade-tree in- sects. Arsenate of lead is a white, flocculent poison, of light, specific gravity, remains suspended in water, hence it requires but little stirring, and adheres tenaciously to the foliage for an entire season. While not as quick in its effect on the insects as the two insecticides previously men- tioned, this difficulty may be eliminated by increasing the quantity used. Arsenate of lead also will not injure the most delicate foliage, hence the extreme care and accuracy necessary where London purple or Paris green is used are not needed. Because of the general demand for this material, several manufacturers are putting it on the market in paste form, at a price ranging from 15 to 25 cents per pound, ac- cording to the size of the package. These pastes carry from 50 to 68 per cent actual dry arsenate of lead, and are very convenient for general use. In large spraying operations, however, it is sometimes desired to make the arsenate of lead from the ingredients, and where skilled labor is avail- able this can be done with little difficulty. The materials necessary are nitrate of lead and arsenate of soda of 96 per cent purity. It is important to get a high-grade arsenate of soda, as the low grades contain a considerable amount of common salt, which will form chloride of lead, — a substance of no value as an insecticide, but which consumes the lead salt. The formulae to be followed are given below : — No. 4.] SHADE-TREK INSECT PROBLEM. 99 Ibs. Ibs. Ibs. Arsenate of lead desired, ... 1 2i 5 Nitrate of lead required, . . .1.2 3 6 Arsenate of soda required, . . . .5 1.25 2.5 Total weight of ingredients, . .1.7 4.25 8.5 These ingredients should be carefully weighed, placed in separate packages, and, when wanted for use, dissolved in separate wooden or fibre pails. When the solutions are completely formed, pour the contents of each pail into a spraying tank partly filled with water. Arsenate of lead will then appear as a fine white precipitate. The above formula? are based on nitrate of lead containing ()i>.5 lead oxide, arsenate of soda of 96 per cent purity (con- taining 59.8 per cent arsenic oxide), the arsenate of lead required being the actual dry product. It will be noted that the ingredients give a little more than one-half their weight in actual arsenate of lead. The same holds true with the arsenate of lead pastes previously mentioned. The cost of ingredients is a variable quantity. Arsenate of soda 96 per cent pure retails at about 15 cents per pound, and nitrate of lead at about 10 cents per pound ; therefore the cost of one pound actual arsenate of lead would be about as follows : — Nitrate of lead, 1.2 pounds, at 10 cents, . . . $0 12 Arsenate of soda, .5 pound, at 15 cents, . . . 075 Bags, twine, etc., 01 $0 205 To these figures should be added the cost of the labor of weighing and packing the ingredients, and that consumed in dissolving and mixing them. Even with these factors included, the cost of one pound of arsenate of lead is somewhat less than that purchased in paste form. The manufacturers of the pastes, on the other hand, urge the superior merit of uniform composition and availability for immediate use, and the saving of time and skilled labor. In small spraying operations, where only a few hundred pounds of the insecticide are needed, probably it would be more advantageous to purchase the prepared paste. In larger operations, where a ton or more of the insecticide is 100 BOARD OF AGRICULTURE. [Pub. Doc. to be used, the parties in charge of the work, knowing their own resources in the matter of skilled labor, and having ob- tained quotations from reliable manufacturers, should be able to decide readily which form of insecticide is cheapest for their purpose. For the elm-leaf beetle and the gypsy moth it is desirable to use the insecticide at the rate of 5 or 6 pounds actual arsenate of lead to 100 gallons of water. For the brown- tail moth, tussock moth and fall web worm, 4 pounds actual arsenate of lead to 100 gallons of water are sufficient. Several park superintendents and city foresters have found advantage in adding glucose when using arsenical insecti- cides, the theory being that this material causes the poison to adhere in a superior manner to the foliage ; and this at one time was our practice in the work against the gypsy moth. Careful experiments, however, involving chemical analyses of foliage sprayed with the same quantities of arse- nate of lead but with and without glucose, showed no in- crease where the latter was used. This result was confirmed by picking foliage from the sprayed trees several weeks after the spraying, and feeding it to caterpillars. The death rate in the two cases was practically the same. There can be no harm, however, in using the glucose, and it is pos- sible that its addition results in a better suspension and dis- tribution of the poison. Not less important than the subject of insecticides is that of spraying outfits. Of these it may be truly said that their name is legion, and a glance through the catalogues of pump manufacturers will show an assortment of outfits suit- able for spraying almost any kind of crop or tree. While there are doubtless hundreds of outfits suitable for use on shade trees, it will be my purpose to mention only a few standard forms, which experience has shown to be of high value for this specific purpose. First let us consider the needs of the owner of a few shade trees. In many cases he cannot afford, and does not require, the high-priced outfits suitable for park work on a large scale. He can get satisfactory results from an outfit suited for ordinary orchard work, with a slight additional expense No. 4.] SHADE-TREE INSECT PRQBLivM. (US! for ho^e. The bill for such apparatus would be about as follows : — 1 hand-lever pump with air chamber, mounted in a 50-gallon cask, $15 00 100 feet half-inch white cotton hose, at 10 cents, . 10 00 1 8-foot i-inch gas pipe pole extension, . . . 1 00 1 Vermorel nozzle, 60 $26 60 Concerning the pump, it may be said that any of the standard makes, operated by a lever and having an air cylin- der of one and a half inches or more in diameter, a stroke of five inches or more and a suitable air chamber, will give sufficient force for the spraying of even tall elms ; and, as already indicated, the outfit, if properly cared for, would be suitable for orchard and garden work for a term of years. On large estates or in the case of parks or street trees a more powerful outfit will be required. For economy of labor, the pump should be capable of supplying at least four lines of hose. It should have a large air chamber to regu- late the pressure, and its construction should be so simple yet rigid that it can be operated by one able-bodied man. Such a pump has been recently offered in the market and tested in park work at Ipswich, Mass., with most satisfac- tory results. The bill for this outfit would stand about as follows : — 1 pump, $25 00 Suction hose and fittings, 5 00 200 feet half-inch cotton hose, 20 00 2 spray poles, at $1, 2 00 2 nozzles, at 60 cents, 1 20 1 150-gailon hogshead, 1 50 $54 70 Where four lines of hose are to be used, the items for spray poles, hose and nozzles should be doubled. This out- fit will effectively spray the tallest trees, and will readily operate four lines of hose where it is desirable. One of the best outfits ever devised for park or street work is the one formerly in use by the gypsy moth com- ; BOABD OF AGRICULTURE. [Pub. Doc. mittee, and which is now being manufactured in a limited way. This apparatus consists of a 100-gallon tank, mounted on a suitable truck for transportation by hand, a powerful double-acting brass pump with agitators, 200 feet of hose, spray poles and nozzles complete, and can be purchased for the lump sum of $125. The advantages of this outfit over the one previously described are that it requires no team for transportation, the pump is submerged and therefore there is no leakage, while powerful agitators keep the mixture thoroughly stirred. These outfits have been used in the parks of Worcester and Springfield and elsewhere with com- plete success. There is a question whether more and better work cannot be done with two outfits of the kind previously described, as used at Ipswich ; but this is a point which park authorities must settle after examining the respective outfits. It may seem . somewhat strange to pass the subject of spraying outfits without extensive consideration of those operated by power. The writer has carefully examined a large number of these power outfits, secured figures of their cost, etc., and has come to the conclusion that, at least for our New England cities and towns, better and more satisfac- tory work can be done with the same amount of money invested in hand outfits. A suitable gasoline or steam spray- ing outfit cannot be purchased for less than $225, the price ranging upward to $500. A fair estimate of the cost of the power apparatus would be $400, and for this sum there could be obtained three outfits such as used in the gypsy moth work, or seven like those used at Ipswich. The great desideratum in spraying operations is to thor- oughly cover the infested territory. in the shortest possible time. This can be done by a battery of small outfits much more satisfactorily than with power apparatus. These light outfits permit simultaneous attack over the greater part of an entire city, and with a suitable corps of men the spraying can be done at just the right entomological moment ; whereas the same amount of capital invested in one or two power outfits would not permit timely work on a large scale. In addition, where such an outfit breaks down, everything Xo. 4.] SHADE-TREE INSECT PROBLEM. 103 comes to a standstill until repairs, often expensive, can be made. With the small outfits the temporary loss of even t\vo or three will not prevent the continuance of effective work by the remainder, and, as the parts are interchange- able, frequently two broken pumps can be combined to put one of them into working condition. Another objection to the use of power outfits is the in- creased temptation to throw the solution onto the foliage in a stream, instead of in a spray. The pump is backed by adequate power, and nothing is easier for a lazy workman than to open the nozzle and drench the tree, instead of spraying it. Sprinkling is not spraying ; drenching is not spraying. The only effective way to spray a tree and have the poison remain on it is to apply the solution as a fine mist. Take a lesson from nature ; the dew or fog coats the foliage with minute isolated particles of water, which adhere ; the drops of rain roll off. So it is with spraying. The poison in the form of a mist-spray can be drifted into the tree, com- mencing at the top, and the whole tree can be treated with- out the loss of a single gallon of the solution. This is the only right way to spray. The poison dries on the leaves, and is in the right place when the insects arrive. I venture to say that at least one-half of the poor results from spraying are due to a lack of knowledge of how to apply the materials to the foliage. The cost of spraying operations on the scale necessary in park or town work is difficult to compute, yet on no other point is information so much needed by those in charge of trees. The experience of others is the best guide, but even this is difficult to obtain, as most workers very properly de- vote their energies to spraying the trees, and consequently ignore the details of daily or weekly records of work per- formed. The writer, by dint of correspondence and personal solicitation, has obtained the statements given below from reliable sources, and would at this time make thankful ac- knowledgment for the same. Mr. J. A. Pettigrew, superintendent of parks at Boston, Mass., while holding a similar position at Brooklyn, N. Y., sprayed 8,712 elms with London purple, at a total cost of 104 BOARD OF AGRICULTURE. [Pub. Doc. $1,370. This operation included salaries of engineer, fore- man, one double team, one single team and six laborers. The trees were from 15 to 40 feet in height, and approxi- mately one-third of them were sprayed twice ; thus the cost of once spraying the 8,712 trees was less than 12 cents per tree. Mr. Wm. F. Gale, at Springfield, Mass., has had long experience in the work of spraying, and, although he has many very large elms with which to deal, he has reduced the operations to almost an exact science. The figures he kindly gave me are as follows : — Labor, . f 4,069 00 Insecticides, 357 00 Repairs, . . Ill 00 Interest on investment in outfits, .... 106 44 $4,643 44 Number of trees sprayed, 16,000 Net cost per tree, . . . . . . . $0 29 Certain large elms at Court Square cost between $10 and $11 per spraying ; but as these trees are of exceptional size, and stand in a busy public square, their treatment was sur- rounded with more than ordinary difficulties. While connected with the work against the gypsy moth the writer made a compilation from the daily reports of employees of the cost of spraying 212 large oaks and other open land, first-growth trees, at Brookline, Mass. In this case the laborers were paid a minimum of $2 per day, and the item for supervision was larger than would be necessary in town or park work. The total expense was about 49 cents per tree. The cost of spraying 1,500 sprout-growth oaks, ranging from 15 to 40 feet high, at Medford, Mass., was similarly compiled, and found to be 15 cents per tree. At Worcester, Mass., the park commission, through its energetic secretary, Mr. James Draper, has waged a thor- oughgoing warfare against the elm-leaf beetle for three years past. The city forester, Mr. Chas. Greenwood, writes me that he never has kept an accurate account of the exact cost of spraying, but estimates it as follows : — No. 4.] SHADE-TREE INSECT PROBLKM. 105 Trees 8 to 10 inches in diameter, . . f 0 50 to $1 00 Trees 12 to 20 inches in diameter, . . 1 00 to 2 00 Trees 24 to 30 inches in diameter, . . 3 00 to 4 00 Trees extra large, 6 00 to 10 00 Dr. E. P. Felt, State entomologist to New York, has given this subject much attention, and kindly sends me the data of some large spraying operations. At Lansingburg, N. Y., a large number of street trees (exact number not given) were sprayed by Mr. H. "W. Gor- dinier of Troy, N. Y., at a net cost of 23 cents per tree. Mr. Gordinier is personally known to the writer, and, as he carries on contract spraying as a side line, his estimates of cost are entirely worthy of credence. He figures that the actual cost of spraying elms as they run, large, medium and small, is from 50 to 60 cents each. Dr. Felt also writes that in 1900 Mr. F. W. Wells, super- intendent of streets at Saratoga Springs, sprayed 5,667 trees at a net cost of 17 J cents per tree. The trees were between 20 and 80 feet in height. The outfit used was a power sprayer with elevated tower. These varied estimates will give a general idea of the cost of spraying operations as carried on both with hand and power apparatus. It should be borne in mind that in some cases cheap spraying is not always the most effective. The figures given by Mr. Gale are to my mind highly suggestive when applied to Massachusetts conditions, although they are lower than would be the case in the average town or city, because of the large number of small elms which were sprayed from the ground. The writer's estimate of spraying trees once with arsenate of lead, using a suitable hand outfit, and with labor at $2 per day, is as follows : — Trees 10 feet tall, . $010 Trees 15 feet tall, 15 Trees 20 feet tall, 25 Trees 30 feet tall, 40 Trees 40 feet tall, 50 Trees 50 feet tall, 1 00 Trees 60 feet tall, 2 00 Trees 70 feet tall, 4 00 Trees 80 feet and over, . . . . $5 00 to 10 00 106 BOARD OF AGRICULTURE. [Pub. Doc. These figures will vary with the efficiency of the men, the distance water must be carried, and other considerations that may come in to help or hinder the work. The question of who shall bear the cost of suppressing noxious shade-tree insects is being settled rapidly by public- spirited citizens, so far as street and park trees are con- cerned. Such trees being public property, their protection is a public duty, and there is no better index to the charac- ter of a community than the care given its shade trees. While municipalities afflicted by outbreaks of shade-tree pests are dealing with them energetically as a rule, there is one factor that often hinders the success of municipal work. I refer to the unrestricted occurrence of these insects on private estates. It profits little to spray street trees for the tussock moth, for example, if on adjoining estates the in- sects are allowed to run riot and reinfest the treated trees. Such negligence is clearly of the nature of a public nuisance, and should be dealt with accordingly. If the municipal machinery is organized to care for shade trees in public places, it may well be used to prevent the injury coming from unsprayed private estates, the expense being levied upon the owner, or met from the municipal treasury, as the community may elect. The essential thing is to keep these pests in subjection, but the question of who shall bear the expense has often prevented thorough remedial treatment. A view which commends itself to the writer is that by the suppression of these pests, wherever they occur, property owners in the entire municipality are protected, and hence can well afford to bear their part of the cost in taxes, as a premium paid for immunity from direct loss. It may be that before such operations can be carried on addi- tional municipal or State legislation will be necessary. If the plan appeals to the judgment of tree, lovers, let them give it their serious consideration, for the need certainly is a pressing one. In the matter of tree protection all citizens should take a lively interest. See to it that the care of your trees is placed under proper supervision and in the hands of a com- petent man. The growing tendency of making all munic- No. 4.] SHADE-TREE INSECT PROBLEM. 107 ipal offices the spoils of political victory has as bad an effect on shade trees as it has upon schools, fire departments or police forces. Illustrations of this point can be found in cities which shall be nameless, where the hand of politics has dropped incompetent men into offices nominally in charge of miles of shade trees, — cities where the elm-leaf beetle and tussock moth have actually killed valuable elms, while those in charge failed to lift a finger until irretrievable damage had occurred, and then contented themselves with sweeping the insects into the gutters, to be farther distrib- uted by showers. All this is not in keeping with the spirit of the time% and it is the citizens' duty to ask and obtain a change. Springfield, Worcester, Northampton, Plymouth and scores of other municipalities have shown what can be done by intelligent, well-directed effort. The successful prosecu- tion of this work is creditable alike to those in charge and to the enlightened sentiment of a public that has made it possible. We said at the outset that perhaps it was well that audible speech had been denied our grand old shade trees. Yet, lacking voices, they have spoken to men like Gilbert White , Thoreau, Whittier, Holmes and Bryant, — men in broad and complete sympathy with nature in all her forms. And sympathy was the key which unlocked the portals and let them into closest association with the whole living world. Wo need more of this feeling for all manifestations of life. o And when we obtain it, we too may hold converse with the tree guardians of our dwellings and streets. Let us so act that the messages they may bring us shall not be the sad notes of neglect or reproach, but rather the sweet harmony of a beautiful, peaceful existence. Ex-Governor HOARD. The lecturer spoke very slight- ingly of the English sparrow, and I do not owe him very much good-will, but I do know a few things about him, and I am impressed with the thought of where the English sparrow gets its food for its young ; for every single bird on earth, except the pigeon, feeds its young on animal food, and 108 • BOARD OF AGRICULTURE. [Pub. Doc. may it not be possible that the English sparrow helps a little while he is rearing his young? Mr. KIRKLAND. I think a paper has just been published by Mr. S. D. Judd, on the "Food of nestling sparrows," that covers that point very well. The sparrow feeds its young in part on spiders and soft-bodied insects, but changes the diet to grain as soon as the young can stand it. Ex-Governor HOARD. I have seen them feed them on cabbage moths when nearly full grown. Mr. KIRKLAND. There is no question but they eat more or less insects, but of course they are grain-eating birds, and should not be classed as insectivorous birds. Mr. JAMES DRAPER (of Worcester) . I should like to say a word or two to supplement one or two points not brought out by the lecturer. In addition to the treatment he sug- gested, we commenced the scraping of the bark of the elm trees, going up fifteen to twenty feet from the ground, getting off all the bark we possibly could and gathering it and burning it, and in that way we destroyed millions and millions of the pupae. Then, in addition to that, at the first treatment, several years ago, we sprayed the trees with kerosene emulsion, but we gave up the spraying process later, and took a stiff fibre brush which we could rub up and down quicker than we could spray the trunk. Mr. KIRKLAND. The spray used was for the trunks of the trees? Mr. DRAPER. Yes. Then we followed up the spraying process as suggested by friend Kirkland very effectively, and wherever the work was thoroughly done the trees were pre- served. But we ran across this trouble : parties owning trees on private estates did not care to have them sprayed, and those trees would be the nesting place for a large quantity of beetles, and those trees have been injured very seriously. There is the great difficulty that we labor under. We take care of our shade trees and park trees and perfectly protect them, and yet the owners of private trees do noth- ing, and their trees are injured. You say, " Why don't you go in and take care of them ? " We have no right to enter upon private estates for that purpose, nor have we Elms of Worcester Common protected by spraying from injury by elm leaf beetle. No. 4.] SIIADK-TRKK IXSKCT I'KOBLKM. !<><) any right to take public funds to apply on private estates. We got a ruling from the city solicitor, to see if we had the right to do it. He said, " If you have a right to do it for the elm-tree beetle, you have a right for any other pests." I think it is the particular province of a meeting of this kind to discuss and see if there cannot be some measure provided to get help in this direction. One word more in regard to this equipment. Instead of having one or two large outfits, we had ten constructed, and had them made to order after the pattern used by the gypsy moth committee. Instead of iron fittings inside, we had them made of brass and composition, so there was no rust- ing. Instead of two wheels, we have them on low, four- wheeled trucks, which are easier to handle than these tall, ungainly wheels. We have ten of the pumps, and they are doing very decent work. City Forester GALE (of Springfield). The essayist has covered the elm-tree beetle question so thoroughly, I do not think I can say anything more in its favor. But our expe- rience has been that spraying thoroughly protected the trees. If the trees are thoroughly sprayed in the early part of the year, as soon as the foliage is established enough to bear the treatment, fully developed, the trees will go through the season without any damage from any leaf-eating insect. As far as the trouble from private estates is concerned, that is the great problem. We have in our city a good many public-spirited people, who are willing to pay their share of the cost and glad to have their shade trees sprayed. We treat all those at the expense of the owners. Our earnings this year have been, perhaps, a thousand dollars from that source. But there are a great many whom we cannot reach, from the fact that, as has been stated, we have no authority for going in there, and of course have no right to expend public money for that purpose. But there should be some- thing done. The law of France that the speaker has re- ferred to is just what we want. We want to have something to compel the property owners who are indifferent and care nothing for the general appearance to allow us to spray their trees and rid their premises of injurious insects. I hope 110 BOARD OF AGRICULTURE. [Pub. Doc. the time will come when we can do that. There is but one sure protection against the elm-tree beetle, and that is by thoroughly spraying the foliage, and that applies also to other beetles and insects, as the speaker has said, and he has covered the ground very thoroughly. The apparatus we use with the best success is the one used by the gypsy moth people. I have fourteen small fifty-gallon cask pumps and two of the larger ones, and I shall use two more this season. The importance is in doing the work promptly. The entire city or town wants to be covered within a given time. When one section of the town is ready, it is all ready, and it is important to have sufficient apparatus to cover the whole territory at once as nearly as may be. If it can be done within ten days, all the better. I mean to cover our en- tire section within three weeks, unless weather prevents. QUESTION. What insecticide do you use? Mr. GALE. Arsenate of lead. The CHAIRMAN. Isn't there considerable that can be done by the individual with the beetle ? Mr. DRAPER. In the larval state, of course, individuals can destroy thousands by simply brushing them down every morning. We have one lady in our city who is very much interested in the matter, and I cannot say now how many thousands she has gathered, but a great many of them. She has a little cotton band covered by newspaper, where the larvae gather during the night, and every morning she takes them out by the quart, or in great quantities, and destroys them. A great many of the larvae come down trees that are not sprayed. It is not always that they come from the tree they are on. Sometimes they come from other places, where no insecticide is used. We have had experience this season with trees that had been thoroughly sprayed where larvae came down, and it was reported by some of the newspaper people that they were thoroughly eaten up from the larvse of the beetle. Within fifty feet of these trees were two trees on private grounds that had not been treated. Before the larvae had finished feeding, those trees were stripped, while the trees that were sprayed were perfectly green. Mr, PRATT, I would like to ask, have you any evidence No. 4.] SHADK-TRKK INSECT PROBLEM. Ill of trees that have been stripped for several years being entirely destroyed or killed ? Mr. DRAPER. We have had only a few. We have had the beetle now six years. There are two trees which have been stripped three years repeatedly, which are not entirely dead, but the greater part of them is dead. Mr. PRATT. In case of the gypsy moth, two or three shippings were death to the tree ; but I think the elm-tree beetle does not work as severely on the tree as the gypsy moth. Mr. DRAPER. I would like to say that I had a corre- spondent in Paris who told me that three or four hundred trees had died from repeated strippings, and that three or four defoliations would kill them out entirely. But I think the American elm would stand more. The English elm might give it up after three or four years. Mr. BABB. One thing that remained with me from the morning, brought out by Mr. Clark, was in regard to the use of glucose with the arsenate of lead. The question was not answered exactly this morning. I should like to ask Mr. Kirkland about the use of glucose, — whether it is necessary. Mr. KIRKLAND. In the early days of the gypsy moth we used glucose as a matter of course, and had faith in it ; but there were some things that led us to doubt the advisability of using it, and we made a series of experiments. We sprayed some oak bushes with glucose and arsenate of lead, and other bushes with the arsenate of lead in the same pro- portion and no glucose. Professor Fernald with Mr. For- bush saw those bushes a few weeks after. They could see no evidence of difference in the two lots. We took the foliage at the end of about six weeks, counted a number of leaves from each bush, and fed them to caterpillars. The killing of the caterpillars was practically the same in each case. In September, some months after the spraying, we cut whole bushes and picked off the leaves from each lot, and had an equal weight of those leaves examined by a chemist, and he found practically no difference in the amount of arsenic present. The next year we dropped the use of 112 BOAKD OF AGRICULTURE. [Pub. Doc. glucose and sprayed with arsenate of lead with no glucose, and it was the most successful year we had ever sprayed. Perhaps the greater success was due to the improvement in the outfit. I do not think the glucose helps the poison to adhere. It may, by making a more dense solution, insure a better distribution of the poison. The chemist told me that after the first rain yo.u could find no glucose on the leaves. Mr. BABB. I asked the question because it seemed tome Mr. Clark was a strong advocate of glucose, and my opinion was it was not necessary, an unnecessary expense, so might as well be saved. Mr. CLARK. I would answer that question in regard to glucose that the expense of it is almost nothing, and it does make the arsenate of lead adhere most thoroughly. I began the campaign against the elm-beetle the earliest of anybody in this valley, probably. I commenced with one three-horse steam-power boiler, and I think for all large towns and cities it is well to have one steam sprayer for the work, because it is very difficult to put ladders up 70 and 80 feet, and we have trees here nearly 90 feet high. With a steam sprayer we can spray these high trees very fast, and by an attachment we have on the engine we can spray two small trees at the same time with the steam sprayer, — trees 30 or 40 feet high, if it is required. Of course for the smaller trees of the town, I think it certainly is well to have the Ware pump that has been spoken of here. I believe that is the one used in Worcester. Mr. DRAPER. Yes. Mr. CLARK. In buying that pump I wish to say this, you want to buy it entirely with brass connections, because those fitted with steel or iron will corrode. With brass fit- tings it can be used for years. I have prepared a little paper for superintendents of parks, part of which I would like to read to you, because it gives a hint of how to com- mence the work : — First, examine carefully, in the month of July, all the elm trees under your care, and see if any of the leaves are skeletonized, — that is, if the green portion of the leaves is eaten out and the skeleton left, No. 4.] SHADE-TREK INSECT PROBLEM. 113 Second, nail a galvanized-iron tag about one inch square on all trees found infected in the slightest degree, making an accurate list of all such trees and the exact location, tak- ing in also all trees on private ground adjoining, so as to know just where to begin the work. Third, get your apparatus purchased before the month of May, or this coming winter, if possible, so as to be ready for your work next spring. The apparatus should comprise, for ladders, one three- section extension ladder, 60 feet ; one two-section extension ladder, 45 feet ; one single ladder, 35 feet ; one single lad- der, 20 feet; one single ladder, 12 feet, for each gang of five men where both large and small trees are to be sprayed. The best sprayer that has come to my knowledge is the Ware hand pump, made for and used by the gypsy moth committee. It is fitted with hardened brass fittings, is worked by one man, and will spray two trees at once, but not quite so rapidly as a steam pump sprayer. When there are a large number of large trees, 50 to 80 feet high, I recommend a two to three horse-power boiler and a duplex steam pump. The one I use is manufactured in Springfield, Mass., and will rapidly spray trees 80 feet high by using a little larger nozzle for the top branches. Be especially careful to spray both sides of the leaves, as the beetle attaches its eggs on the under side of the leaf, and the worms begin to feed there as soon as they are hatched out. The early spraying is then far the most effective, as it kills both beetles and worms. Always commence spraying at top of the tree. Spraying poles 10 feet in length with attachment for nozzles can be had for $3, and are very valuable for high spraying. Although you want for most of the spraying work a noz- zle that will spray, I find it better to use a little larger straight-tip nozzle, so as to be sure to thoroughly wet the top branches of high trees, — the most difficult work to be done, as the beetles resort there when driven from the lower part of the trees . A low one-horse truck for transporting the hand-pump, 114 BOAED OF AGRICULTURE. [Pub. Doc. 100-gallon truck and other apparatus, can be bought for $35, and is just what is needed for use in the field or street. In regard to scraping the bark off, since we have the arse- nate of lead spray I don't think there is need of it. Taking all the bark off the tree certainly has a tendency to make its bark too thin for winter protection, and is liable to injure the tree. I have had pretty good success. In Florence I commenced spraying about five years ago, and we have practically exterminated the beetle. The question has been asked about the killing of the trees. You can go through Longmeadow, a town that has been neglected, they haven't sprayed at all, and see the ends of the trees dying. If you neglect the tree, it is certain to die. If the trees are not sprayed, they will commence to die down. Dr. H. T. FERNALD (of Amherst). It seems to me there are some items that should be spoken of with reference to how far our authorities permit us to enter upon private prop- erty for the control of noxious pests. That question, I think, is one of the most important we shall have to deal with in the next fifty years, because the number of insect pests is spreading rapidly all over the country, and they are not pay- ing any attention to property lines or fences. The park or the city authorities may clear all the public ground of those noxious pests, but if they are unable to control those pests on private grounds, and the owners of those grounds do not co-operate with the public authorities in the matter, any attempts come to no result. The question has recently been discussed as to the power of public authorities to enter pri- vate grounds for those purposes, in a meeting of official hor- ticultural inspectors of the United States, held at Washington some two weeks ago. At that time it was decided that the present laws in most of our States are very defective, in that they do not make clear that the authorities have a right to enter upon private property, or in some States they said that they have no such right, and that a person so entering upon private property is liable to a suit for damages. It was the sentiment of that convention, at which I was present, that this was a very unfortunate condition of affairs, but never- No. 4.] SIIADK-TRKK INSK(T I'KOHLKM. 115 thelrss it was the present state of the case, and the only way of controlling insects and other pests distributed impartially on public and private grounds was by co-operation of the public authorities and private owners. Unfortunate as this conclusion may be, it is at all events the condition which confronts us at the present time ; and we must work either on that basis or work for a change of our laws that will recog- nize, perhaps, what we consider the law of "public nui- sances," and obtain an application of that law to public pests. Perhaps in that line we may look towards relief in the future, if we do not have it at the present time. Mr. Kirkland has said, if I understood him correctly, that one-half of the failures of spraying were due to not know- ing how to apply the spray. I entirely agree with Mr. Kirkland in that, and I would like to add that in my opinion the other half of the failures in spraying are due to not knowing how to make the material to put on. Anybody who has tried to- make up arsenate of lead from the chemi- cals, and who has gone to a drug store and bought those chemicals and run his risk of the adulteration, and has tried to get arsenate of soda 96 or 98 per cent pure, and then gone to work and tried to get it into a gallon of water in the proper proportion, — by the time he has done that he is generally a pretty thoroughly mixed up man the first time, and sometimes a good many times thereafter. That is one reason why Paris green remains in favor. Most men I find start out with Paris green, and they say it is because they have only to dump it into the water. They get mixed when they try to prepare insecticides. The trouble is, we need more or less of chemical training to keep us from dropping into pitfalls. They are all about. I have never seen a man that succeeded in making a kerosene emulsion, that was an emulsion, the first time. For that reason I think we must look for a fixed supply of definite insecticide materials ; and I do not know but that it is the natural modesty of the speaker who has just concluded, but it seems to me he has left something unsaid. Mr. Kirkland could not speak from his position as I am able to. I acknowledge the feeling that we must have an insecticide which demands only the addi- 116 BOARD OF AGRICULTURE. [Pub. Doc. tion of water or only simple treatment to prepare. I do not believe in advertising in a general way, but where I can hon- estly recommend a thing I feel it is as much my business as to put down a moth catcher such as they got out in Missouri last year. I consider that the Bowker insecticides, among others, are excellent and reliable ; and one of the best points about them is, there is no weighing out so many ounces of this and that and heating it in a steam boiler, and stirring it so long, and perhaps muttering a charm as you do it, but you have it right in hand, and that is where it should be every time except for those of us who have opportunity to experiment and practise until we get the results well under our control. These gentlemen have a great advantage over the average man who has his spraying to do in a hurry, right then, with other work pressing in every moment. If I had acquaintance with other firms, I might be able to say the same thing. I have not that fortune. I speak of what I know. The brown-tail moth has been spoken of. Let me say that one of my duties as one of the nursery inspectors of the State has taken me into nurseries in several parts of the State, and in several of these nurseries the brown-tail moth is abundant. That means if men buy nursery stock they are liable to bring the brown-tail moth here, or to Pittsfield, or anywhere in this State or other States ; and the only protec- tion you have against the brown-tail moth or the San Jos6 scale is such protection as is given by requiring the nursery- man to give a certificate that his nursery has been examined and none found. The failure to do that has cost the loss of thousands and thousands of dollars to this State, and is going to cost the loss of many thousands of dollars more in the same line. It behooves every man who intends to be careful about the stock he buys to see that it is covered by a certificate that declares protection to that stock. Mr. DRAPER. In the line of what Dr. Fernald has said, I wish to emphasize the same point brought out by what he said. I am a student under our friend Kirkland in this matter of insecticides, and while he was with the gypsy moth committee, he came and gave us instructions in the preparation of kerosene emulsion and its application, and Xo. 4.] SHADE-TREE INSECT PROBLEM. 117 we followed his directions and the result was satisfactory. I omitted one part of my little talk about the use of kero- sene emulsion. I spoke of simply using it on the trees. Instead of resorting to hot water, as suggested by my friend from Northampton, we sprinkled the trunks and around the roots of the trees with kerosene emulsion. I think that is easier than to try to keep water hot. Mr. CLARK. I would answer that by saying I have ex- perimented upon the larvre and pup*e with both, and it was found the hot water was more effective. The other is good, there is no question about its being very good indeed, but \vhiMi you put on the hot water there is no possible escape. When you. put on the boiling hot water, everything is gone as far as life is concerned. The hot water costs nothing, and the kerosene emulsion costs considerable. Mr. DRAPER. It is not the purpose of the speaker to ad- vertise anybody's goods or to advertise Mr. Ware's pump, but that is, in my judgment, the best equipment for our park and street work. You are obliged to have your ladder men as well as the tree men, that we call " squirrels." You have to have the ladder men, and they can just as well work the pump, and one of these pumps will run four lines of hose on most of your trees, and that is about as fast as you can do it. I don't believe it is policy to go into the steam pumps. One word more. Our experience in making arsenate of lead was fairly satisfactory. We took the formula from Mr. F. J. Smith of the gypsy moth committee and tried to make it ourselves, and it was fairly satisfactory. But when Mr. Kirkland went into this company and they put out a mate- rial that all we had to do was to put it into the tank all readj^ mixed, I thought they were doing a great service to those fighting the insect pests, and I use that chemical as furnished by them, and it has been entirely satisfactory to us the past year. The CHAIRMAN. It seems to me it demands a little explanation as to the Ware pump and the arsenate of lead. The committee who had charge of the gypsy moth work felt the necessity of a better insecticide than Paris green, because of the danger of burning the foliage, and the 118 BOARD OF AGRICULTURE. [Pub. Doc. complaints that were brought in from private individuals that their trees were injured. A chemist was employed and set at work, the committee getting all the hints from other chemists possible for the chemist they employed. Pro- fessor Fernald was consulted, Dr. Wellington, Professor Shaler and others, and hints were gotten from all sources possible, and this chemist put them in practice and tried everything, first one thing and then another and another, and the outcome was arsenate of lead. This morning per- haps undue credit was given to the chemist who did the work. He did the work, but he got hints from educated men everywhere. Probably a hundred different compounds were suggested and tried, and none of them excelled Paris green until we struck the arsenate of lead, and that filled the bill. In regard to the pump, we found in the immense amount of spraying we were obliged to do, on trees one hundred feet high, bushes and all kinds between, over hundreds of acres, we must have better facilities for spraying than we did have. We found a man willing to work under our direc- tion, getting hints wherever he could, from experienced men, scientific men and practical men, and put them together for this spraying machine. That man was Mr. E. C. Ware. Mr. Ware made this machine for the State of Massachusetts, and the State of Massachusetts paid the bill, as it paid all the bills for the discovery of the arsenate of lead ; and when the committee made the contract with these men, it was agreed that any discovery they made under the pay of the State of Massachusetts should not be patented, but should be reserved for the use of the people of the country, free, and that is the condition of the arsenate of lead and of the Ware pump. If you can make a Ware pump, you have a right to make it. If you can make arsenate of lead, you have a right to make it. With reference to Mr. Bowker's arsenate of lead, he did not invent it. He puts together the invention that the State of Massachusetts made, and if he can put it together better than anybody else, he is the man you ought to buy it of. If he is not, then you ought not. No. 4.] SHADE-TREE IXSECT PROBLEM. 119 Professor BROOKS. Many of you know that all trees or shrubs which come from Japan are, as a rule, free from the attacks of our insects. The Japanese insects prey upon them to the same extent that ours do. When I came from Japan I brought a few Japanese elms that I found growing wild about the country where I lived. I do not know whether I have the only tree of the kind in the country or not. I think perhaps Professor Sargent has them now, because he has been over the same ground recently. This tree that I speak of was planted where it stands, behind my house, in the spring of 1890. It is now about seven or eight inches through at the butt and about thirty feet high, a very shapely tree. All the elms I saw in Japan were shapely trees, — perhaps not equal to ours, but very shapely. This tree is not attacked by the beetle. It stands in the midst of native elms. This past summer those elms were stripped, while the Japanese elm was not injured appreciably. This is a point some horticulturist or nursery- man may like to know. I hope efforts will be made to introduce the tree here, because it is a means of enlarging our resources. It is a handsome tree, altogether apart from whether it proves permanently to be free from insects. Prof. C. H. FERNALD. I have a word to say very briefly upon what Professor Brooks has said. A year ago last summer, while in Plymouth, Mass., I went to the famous old graveyard, and there saw the elm trees being defoliated by the elm-beetle, and after they had stripped those they went to the maple trees and stripped the maple trees. That is why I asked Mr. Gale the question, to see whether the elm-tree beetle has been found going to other trees. If they would take the American and the English elm trees and strip those, and then go to the American maples — a red maple, I suppose it was — and strip those, I should doubt whether any species which came from any country would be safe. They would naturally have a preference for that food plant, and would take our American elms first ; but after they had done writh that food I should doubt, from what I saw in Plymouth, whether they would not eat the other trees as well. 120 BOARD OF AGRICULTURE. [Pub. Doc. The CHAIRMAN. I think canker worms do the same thing. Professor BROOKS. I do not care to prolong this discus- sion. I stated simply a fact. Other neighboring trees were depleted, and those Japanese elms were not. As far as the taste of the insect is known, I believe all destroy the leaf, and this elm has a thicker and more hairy leaf. It might be possible the beetles would eat it. I do not pretend to say they would not. I simply state the fact observed this past season. EVENING SESSION. The evening session was called to order by Mr. A. M. Lyman of Montague, delegate from the Hampshire Agricult- ural Society, who introduced as the lecturer of the evening Maj. Henry E. Alvord of the United States Department of Agriculture. The lecture, "Dairying in France," was illustrated by the stereopticon. •&• HICKORY BARK BORER. 26/ through a force pump for about five minutes, until the whole forms a creamy mass, which thickens upon cooling. For use, dilute nine times with cold water. The mechanical mixture is made by using a special form of pump, which mixes the two liquids under pressure. The trees along Broadway have unquestionably been injured by gas escaping from the main. They have also suffered great injury from the beetles, and the combined effect of gas and beetles has killed some of the trees. All residents should cooperate with the city authorities to kill as many of the beetles as possible right away. It is hoped that the municipal authorities of Connecticut will be on the alert the coming season, and in readiness to spray the elm trees with poison if the beetles should be dangerously abundant, and thus prolong the lives of the trees, which, with their various other troubles, already have a precarious existence. A SERIOUS INJURY TO HICKORY TREES BY THE > HICKORY BARK BORER. Scolytus quadrispinosus Say. On August ist, in answer to a request, the writer visited "Sachem's Wood," New Haven, to examine the hickory trees, which were in an unsatisfactory condition. Many trees had died, and many more were fast losing their vitality. The foliage was falling from the supposedly healthy trees and the ground was literally covered with fresh and dried leaves. The many dead leaves still on the trees gave them a brown and scorched appearance. An examination of the twigs revealed great numbers of small black beetles, nearly one-fourth of an inch in length, which were boring holes in the axils of the compound leaves (see fig. 2), cutting them off in many cases so that they fell to the ground. In some instances the twig was eaten to such an extent that it broke off (see Plate VIII, b). The trunks of the dead and dying trees were the breeding grounds of the beetles, and larvae, pupae, and adults were numerous under the bark. The adults were emerging from the bark through small circular holes, which were so abundant that the tree appeared to have been filled with shot. Specimens were sent to Washington for identification, and the beetle found to be Scolytus quadrispinosus Say. The late Dr. C. V. Riley studied this insect in Missouri in 1872, and 1 268 CONNECTICUT EXPERIMENT STATION REPORT, IQOI. believing it to be a new species, described it as S. carya* Later it was found to be identical with Say's quadrispinosus. Fig. eetle injuries to other trees 320 Oaks, chestnut, birches, and poplars killed by bark-boring grubs 320 Methods of control 321 Insect injuries to the wood of living trees 323 Pinhole injuries in oak wood 323 Pinhole and wormhole injuries to chestnut wood 324 Characteristics of the chestnut timber-worm 325 Methods of preventing losses 325 Carpenter- worm injuries to oak and locust 326 Methods of control 327 Work of the Columbian timber beetle 327 Character of the work 327 in ILLUSTRATIONS. PLATE. Page. PLATE XXXIX. Fig. 1. — Character of larval mines of oak-destroying bark- borer in inner surface of bark. Fig. 2. — Larval mines of destructive bark-borer in surface of wood of dying cotton- wood tree 320 TEXT FIGURES. FIG. 27. Work of the hickory bark-beetle on surface of wood beneath the bark. 315 28. Complete brood galleries of the hickory bark-beetle in surface of wood 316 29. Exit holes* in bark of hickory tree from which broods of the hick- ory bark-beetle have emerged 317 30. Brood galleries of the oak bark-beetle 318 31. Brood galleries of the cherry bark-beetle, showing character of pri- mary galleries and larval mines _ 319 32. Work of the birch bark-beetle 320 33. Brood galleries of the ash bark-beetle in surface of ash wood 321 34. Mines of a destructive bark-borer 322 35. Pinholes in oak — work of the oak timber-worm 323 36. Wormholes in chestnut— work of the chestnut timber-worm 324 37. Wormholes in red oak — work of the oak carpenter worm 324 38. Work of the Columbian timber-beetle — black holes and t( grease spots" in white oak 325 39. Work of the Columbian timber-beetle — " steam boats" in quartered or split white oak 326 40. Work of the Columbian timber- beetle in tulip wood — ' ' calico poplar ' ' . 326 41. Work of Columbian timber-beetle — end of log showing evidence of serious damage, and how the brood galleries made in the sapwood are covered by subsequent growths of wood 327 42. Work of Columbian timber-beetle in sapwood of living tree 328 43. Brood gallery of Columbian timber- beetle in sapwood of white oak. . 328 IV INSECT INJURIES TO HARDWOOD FOREST TREES. By A. D. HOPKINS. /// ( 'hurt/i' of Forext Inwcf Investigations^ JHrlxion of Entomology. EXTENT OF DAMAGE DETERMINED HY SPECIAL INVESTIGATIONS. Within recent years the writer 1ms conducted investigations in the principal hardwood forests of the country for the purpose of deter- mining the extent and character of damage caused by insects, and especially that which results in direct losses to the owners, manufac- turers, and consumers of hardwood forest products. This resulted in finding that oaks, chestnut, hickories, maples, birches, walnuts, cherry, tulip or yellow7 poplar, gums, and others of our principal hardwood, or broad-leaved, timber trees are damaged to a far greater extent than U realized by the casual observer. A large percentage of the hard- wood timber in nearly all of the States east of the Rocky Mountains is affected, and the average annual losses from this source we would estimate at between 15 and 20 million dollars. There is not only a direct loss to owners of forests, and manufacturers and consumers of forest products, but the continued depredation is contributing to the rapid depletion of the available hardwood timber supply of the country. THE CHARACTER OF INSECT INJURIES TO LIVING FOREST TREES. The character of insect injuries to living forest trees may be discussed under two distinct heads: (1) Injuries which cause the death of the trees. (•2) Injuries to the wood which do not materially affect the vitality- of the trees, but cause serious defects in the parts which furnish com- mercial products'. There is also great loss from insect injuries to felled timber, saw logs, round and square timber, lumber, and other crude products, but the limited space allotted here will not permit a discussion of this phase of the subject. 313 314 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. INJURIES WHICH CAUSE THE DEATH OF TREES. The principal insect injuries which result in the death of trees are burrows through and beneath the li\7ing bark of the trunks. There are two distinct classes of these injuries, one caused by bark-boring beetles, the other by bark-boring larvae or grubs. INJURIES BY BARK-BEETLES. The adults of this class of enemies bore into and beneath the bark for the purpose of excavating galleries in which to deposit their eggs. These galleries are the primary injury which weakens the vitality of the trees, while the secondary or larval mines complete the girdling process which kills them. INJURIES BY BARK-BORING GRUBS. This class of injuries is caused by larvae which hatch from eggs deposited by the adult insects in the outer bark, and never in burrows beneath it; therefore the burrows made through the living inner bark by the young not only cause the primary injury, but complete the girdling process. The form of the barrows or galleries is, as a rule, sufficient to iden- tify at once the class to which a given injury belongs, and very often is sufficient to identify the insect. BARK-BEETLE INJURIES TO HICKORY TREES. Within recent years the dying of hickory trees has attracted consid- erable attention, especially in the northern tier of States, from Wis- consin to Vermont. The trouble also extends southward through the Atlantic and Eastern States as far as central Georgia and westward to Missouri. Thousands of trees have died, and in some sections nearly all of those in forests, parks, and on farms have perished. This is causing a serious loss not only of a valuable timber product, but of shade trees and the crop of nuts, which latter, in some sections, is of considerable importance, both as a commercial product and for home consumption. This dying of the hickories has been found in every case investigated to be the result of injuries to the buds and twigs and to the bark of the branches and trunks by the hickory bark-beetle (Scolylus Jf-spinosus Say). THE HICKORY BARK-BEETLE. The hickory bark-beetle is a short, stout, shining black or reddish- brown beetle, averaging 3.6 millimeters (0.14 inch) in length. The wing covers are short and project over the abdomen, which in the males is excavated beneath and armed with four rather prominent INSECT INJURIES TO HARDWOOD FOREST TREES. 315 spines, which suggest its technical name. It appears on the wing from Mav to August and hegin> its attack on the living trees at the base of the luuls and leaves, apparently for the purpose of obtaining food; later it enters the bark of the larger branches and top of the trunk and excavates short longitudinal burrows (tig. 27, ,/) in the inner bark and surface of the wood. The eggs, which are placed along the sides of this primary gallery, hatch into small white grubs, or larva?, which burrow at right angles through the inner bark and groove the surface of the wood (fig. 27, It). The broods of larva* pass the winter in these brood gal- leries, and the transforma- tion to the adult takes place in the spring in the outer portion of the inner bark. The adults emerge through holes in the outer bark (fig. 2!») to continue their dep- redations on the buds and branches of other trees and the remainder of the trunks that were not killed by the first attack. They com- mence to emerge about the middle of Ma}' in the latitude of Morgan town, W. Ya.. and two or three weeks later in the latitude of Detroit, Mich. Indi- viduals of the hibernating brood continue to emerge until August, and may be found excavating galleries and depositing eggs as late as September. Thus, they will be found attacking trees all through the sum- mer, and all stages, from very young to matured lar- va1, will be found in the bark at the commencement of winter. In the States north of Tennessee and North Carolina there is evidently but one generation, while farther south there may be two. EXTERNAL CHARACTER OF THE IN.JTKY. The first indication of attack is shown by the leaves, some of which die and remain on the twigs, while others fall earlv in the season. Later, in July and August, the larger branches or the entire top may FIG. 27.— Work of the hickory bark-beetle on surface of wood beneath the bark: a, primary gallery; b, larval mines. (Original.) 316 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. die, while the lower branches and trunk may remain in normal health. Sometimes the entire tree is killed the first season, but more often the lower portion dies from a subsequent attack. Upon examination there will be found the wounds made by the beetles ajb the base of the buds, which cause the leaves to die or fall. Upon removing the bark from the dead branches the characteristic brood galleries will be found in FIG. 28.— Complete brood galleries of the hickory bark-beetle in surface of wood. (Original.) the inner bark and engraved on the surface of the wood (tigs. 27 and 28). If the tree is infested the parent beetles will be found in the primary longitudinal galleries, and great numbers of small, white grubs in the larval burrows in the bark. If the broods have emerged, the bark will be found perforated with numerous small round holes, as indicated in fig. 29. INSECT INJURIES TO HARDWOOD FOREST TREES. 317 METHOD OK COMBATIM; TIIK INSECT. The fact that there is ;i single generation annually, and that the generation* pass the winter in the immature stage in the bark, makes it a comparatively easy pest with which to deal. It is only nores>ary to determine which trees are actually infested at the beginning of winter, and to see that those are cut and the bark burned before the middle of the following May. If the greater number of infested trees over a considerable area are thus treated, the number of the insects will be so reduced that they can not continue their destructive depredations on living trees. It is important to remember that there is nothing to be gained by cutting and burning the old dead trees after the insects have emerged, but that it is of the greatest importance to locate all trees which have died within a year from the 1st of June and are infested, and that these be cut and the insects destroyed before the 1st of May of the year following the death of the tree. In some eases it will be advisable, when the tops and branches only are dead and infested and the remainder of the tree is living, to cut out and burn the infested top and thus save the lower part of the tree. The broods can be de- stroyed without loss of the wood by utilizing it for fuel within the time specified, or, if it is desired for other purposes, the bark can be removed and burned or the logs placed in water until the insects are all dead. The practical application of this meth- od of cutting and burning the infested trees was made by the commissioner of parks and boulevards of Detroit, Mich., on Belle Isle Park, in May, 1903. A great many hickories on the island were infested, and all were threatened with destruction by this insect. Upon request of the commissioner, addressed to the Department of Agriculture, investigations were made by the writer, who recommended that the infested trees be cut and burned before the broods of the beetles commenced to emerge. This plan was promptly adopted, and the cutting and burning of the infested trees was so thorough that no evidence of the destructive work of the beetle on the remaining trees has since been observed. FIG. 29.— Exit holes in bark of hick- ory tree from which broods of the hickory bark-beetle have emerged. (Original.) 318 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. ' BARK-BEETLE INJURIES TO OAK TREES. Different kinds of oaks, of sizes ranging from a few inches in diameter to large trees, are frequently found in the woods dying or recently dead, with no evidence of external injury. If, upon remov- ing the bark from a place on the trunk some 4 or 5 feet above the base of one of these trees, the inner surface is found to be grooved with great numbers of minute transverse burrows, similar to fig. 30, &, which are also faintly marked on the surface of the wood, it is the work of the oak-destroying bark- beetle (Pityophthorus pruinosus Eichh.). This is an exceedingly small dark-brown or nearly black beetle, less than 2 millimeters (0.08 of an inch) in length, which, notwith- standing its small size, sometimes occurs in such vast numbers that large oak trees are attacked and .killed by it in a few weeks. It passes the winter in the adult and larval stage in the inner bark of trees and limbs where it bred the previous summer. It commences to fly early in the spring, and pre fers to enter the bark of trees re- cently felled or injured by storm or other causes. It also enters the bark of large and small branches recently broken or cut from living trees. In the inner bark of these the parent adults excavate short double transverse primary galle- ries, from which the broods of FIG. 30.-Brood galleries of the oak bark-beetle, }TOUng larV86 eXCRVate long lateral showing character of primary gallery at b; mines (fig. 30), Up and down, larval or brood mines at a. . , . . through the inner bark, and folio #- ing the bark fibers in such a way that they are difficult to recognize. Enormous numbers of these brood galleries are often found within a small area of bark. When a large number of trees and branches are infested the swarms of beetles of the first generation will emerge later in the summer, and if they fail to find sufficient felled and injured trees in the right condition to attract them, they will concentrate their attack on a few living trees, which soon perish. The leaves of such trees will first fade, then turn brown, and remain on the branches until the next spring. INSECT INJURIES TO HARDWOOD FOREST TREES. .\IKTIH>|iv OF IONTKOI.. 319 If the trees die lute in the Miimner the broods of the beetles will remain in the bark over winter, and can easily be destroyed by felling the tree>. removing the bark from the trunks, and burning the branches. The removal of the bark in the winter is sullicient to kill the broods, but it is easier to burn the branches than to remove the bark from them. This work can be done at any time between September and the following March. If the trees die earlier in the FIG. 31.— Brood galleries of the cherry bark-beetle, showing character of primary galleries and larval mines. (Original.) season it will be best to fell them and treat as above as soon u< the leaves commence to die, in order to prevent the development and emerging of a possible second generation before winter. It is also important, especially in farmers1 woodlots, to have all tops and branches from oak trees felled during the winter, piled and burned between the 1st of May and the 1st of June. This will allow the spring brood to commence operations in the bark of such material 320 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. before it is burned. All infested tops and branches of summer cuttings should be destroyed, and the bark removed from infested logs dur- ing the winter. Therefore, clean forest management and the prompt felling and removal of the bark from dying trees will serve to prevent serious harm from this insect. BARK-BEETLE INJURIES TO OTHER TREES. The wild cherry is sometimes killed or seriously injured by the cherry bark-beetle (Phlceophthwus limitiaris Harris), but this insect rarely attacks perfectly healthy trees, although it is capable of doing so. The ornamental double transverse gallery of this beetle in the inner bark and grooves of the surface of the wood will be easily recognized by the characteristic form, as shown in fig. 31, although they are seldom found so perfect. The paper birch and other birches of the north woods and higher Allegheny Moun- tains are sometimes killed by the birch bark-beetle (Dryo- c&tes eickhoffi Hopk.). Trees slightly injured b}^ fire, which would otherwise recover, often die from the attack of this insect, yet in such trees they breed in such FIG. 32.— Work of the birch bark-beetle: primary galleries and larval numbers as to attack mines in bark. (Original.) living ones and kill them. The galleries made by this beetle and its larvse in the inner bark (fig. 3:2) differ from the preceding in having no regular form, but penetrate in all directions from the main entrance and the irregular primary galleries. The hackberry bark-beetle (ftcolytus muticus Say), the elm bark- beetle (Ilylastinm rufipes Eichh.), the mulberry bark-beetle (Phlwopk- thorusfrontaUs Oliv.), the ash bark-beetle (Meliobius aculeatus Say— fig. 33), and a number of others of this class of beetles, are sometimes quite injurious, but more often are secondary enemies which attack only injured trees and prevent their recovery. OAKS, CHESTNUT, BIRCHES, AND POPLARS KILLED BY BARK-BORING GRUBS. There has been a great mortality among the oaks and chestnut of the Appalachian region which has been going on for many years. No such large bodies of timber have been killed in any one year as to attract special attention, but scattering trees all through the forest die every year. In some of the southern sections nearly all of the larger Yearbook U. S. Dept. of Agriculture, 1903. PLATE XXXIX. INSECT INJURIES TO HARDWOOD EOREST TREES. 321 chestnut trees on thousands of square miles have died, and in other sections the oaks have died to an alarming extent. Upon investigation in different sections of the country it was found that the oak-destroying bark-borer, or two-lined chestnut borer (Ayrthi* !> 43--Brood *aller>' of Columbian timber- IU.> l beetle in sapwood of white oak: A, inner bark; L U. S. DEPARTMENT OF AGRICULTURE. FARMERS' BULLETIN No. 99. THREE INSECT ENEMIES OF SHADE TREES. BY L. O. HOWARD, ENTOMOLOGIST. [Reprinted, with some annotations by the author, from the Yearbook of the Department of Agriculture for 1895.] WASHINGTON: G O V K R N M E N T PRINTING OFFICE. 1899. LETTER OF TRANSMITTAL U. S. DEPARTMENT OF AGRICULTURE, DIVISION OF ENTOMOLOGY, Washington, D. rown or black in color, for cutting through plant tissue. Some spe- cies mine only in the bark of trees, some mine in both bark and wood, and some confine themselves to herbaceous plants. In each case the borer is hatched from an egg laid upon or in the bark or 1 See " Injuries to forest trees by flat-headed borers," Yearbook, 1909, p. 399. 341 342 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. wood by the parent beetle. It lives and feeds entirely within the bark or wood until it attains its full growth, when it changes to the pupa, or resting stage, within its burrow. The pupa later transforms to a beetle, which emerges and flies in search of suitable places to repeat the process of propagating the species. In nearly every in- stance the entire damage is done while the insect is in the grub, or borer, stage. This form is therefore the most important from an eco- nomic standpoint. ECONOMIC IMPORTANCE. Some species of roundheaded borers kill trees outright by mining in the bark, thus destroying the vitality of the tree, while others injure the wood of dead, dying, or felled trees, or timbers manufac- tured from such trees. Still others both kill the trees and injure the wood for commercial purposes. The annual loss to owners of forest trees and forest products from this source, if figured up in dollars and cents, would amount to a sum far in excess of what the ordinary individual would think possible. CHARACTER OF WORK. The work of this class of insects usually appears as irregular wind- ing mines or " wormholes " in the bark and wood. The mine always starts in the bark, where the minute larva just hatched from the egg starts to bore and feed. At first the mine is very small, but gradually becomes larger as the borer advances and grows in size. As already indicated, the work of some species is confined entirely to the bark. The work of other species is found in both bark and wood. In this case the mine is continuous from bark to wood, the entrance into the wood being a flattened oval hole. That part of the mine which is in the wood may be long or short, according to the species. In general it is more or less winding and irregular, contains borings and woody excre- ment, and finally broadens out into a cell or " pupal chamber." At the farther end of this cell the mine, or " exit burrow " as it now becomes, usually leads directly to the surface by the shortest route. Upon the surface it usually appears as a perfectly round " exit hole " (fig. 21, d). LIFE HISTORY AND HABITS. As a usual thing the adult female beetle lays an egg or a cluster of eggs either in or upon the bark in the spring, summer, or early fall. Sometimes the parent female excavates a pit in the bark with her mandibles, through which the eggs are thrust by means of the ovi- positor. In other cases eggs may be deposited in crevices of the bark or under the overlapping scales of bark. In a few days after the egg is INJURIES BY ROUNDHEADED BORERS. 343 deposited a minute wormlike larva (fig. 10, c) issues therefrom and immediately begins boring into the bark with which it finds itself in contact. The larva usually proceeds directly to the inner bark, or cambium, immediately next to the wood. Here the larva mines and feeds until it reaches a certain growth, when it makes preparation for a change called pupation. The entire growth of the insect is attained in the larval form. Usually, before it at- tains full growth, how- ever, the larva mines either into the solid wood or into the outer corky bark and digs out an elongate oval cell, in which it will soon pupate. From the far- ther end of the pupal cell the larva, as a gen- eral thing, extends the mine almost to the sur- face of the tree or log, in order to facilitate its emergence into the open air when it has gone through its changes in the pupal cell to the adult or beetle form. This wrork completed, it- retires to the pupal cell and awaits the change to the pupal form. Finally the outer skin comes off and the insect has an entirely different form and appearance (tig, 20, d). It is now a pupa. The length of time passed in this form is variable with the species and with the local conditions, the pupa resting perfectly quiescent in its cell during this period. At length another change takes place and the insect is in the adult or beetle stage (fig. 20, &). At first the beetle retains the white color of the pupa and ^arva, and the outer tissue of the body is quite soft. But gradually the color turns darker and the outer tissue becomes hard and chitinous. When FIG. 19. — Work of the western larch bark-borer (Te- tropium velutinum). Sections of bark of western larch : a, Cluster of eggs deposited under overlap- ping scale of outer bark, the overlapping scale, In this instance, having been removed ; 6, inner surface of bark with newly started mines ; c, small larva, a few days old. Slightly enlarged. (Original.) 344 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. fully hardened and mature the young beetle crawls into the mine leading away from the pupal cell and completes this mine to the sur- face of the tree or log. It then flies away. Mating and egg laying soon follow to provide for another generation. SEASONAL HISTORY. Probably in the great majority of cases the larva does not change to the pupa until the spring following the season in which the egg ia laid, passing the winter either in the larval mine or in the pupal cell. However, pupation may take place in the fall and the winter be passed in this stage, or the adult stage may be reached in the fall and the winter be passed in this form within the pupal cell. The following spring the larva? which have wintered over transform to pupae. The pupa? soon transform to adults and the adults emerge and take flight. Likewise, the pupae which have wintered over trans- form to adults and emerge. The first to emerge, however, are those individuals which have wintered over as adults. Sometimes a spe- cies may have two generations a year, or a partial second genera- tion. In these cases development takes place rapidly after the eggs are laid in the spring, the adult insects of the first generation emerg- ing in late summer or fall, and laying eggs for the second generation. The second generation passes the winter as outlined above. In still other and more rare cases two or more years may be necessary for the complete development of certain species. THE WESTERN LARCH BARK-BORER. (Tetropium velutinum Lee.) At the present time the western larch bark-borer is quite a serious pest in the Glacier National Park in Montana. In the vicinity of Lake McDonald about 10 per cent of the stand of western larch or tamarack is being killed annually by this bark-borer. Besides larch it attacks fir, Douglas fir, western hemlock, and pine, in the Rocky Mountain and Pacific coast regions. The eggs are deposited in clusters under overlapping scales of bark (fig. 19, a) and the minute larva? hatching therefrom proceed to the inner bark, where they immediately commence their mines (fig. 19, &). The work of this borer in larch is confined to the bark, though in some of the other host trees mentioned above it sometimes enters the sapwood. The larval mine is irregular and winding in the inner bark. The number of mines is so great as to completely girdle the tree and cut off the sap, thereby causing the death of the tree. Often almost the entire inner layer of bark, or cambium, is destroyed for quite a considerable space upon the trunk (fig. 20, a). INJURIES BY ROUND HEADED BORERS. 345 •s The-grub (fig. 20, c) is elongate and somewhat cylindrical, yellowish white in color, and about 1 inch long when full grown. Its mouth- parts are dark brown to black, and the under side of the body is pro- vided with three pairs of minute legs. It lives in the bark about a year, emerging in the spring or summer as an elongate, brownish to black beetle (iig. 20, ?>), the surface of the body having a velvety appearance. The beetle ranges in length from 9 to 19 mm.1 The principal time of emergence is May and June. This species attacks either healthy, injured, or felled trees. The methods of control are preven- tive. Once a tree is <^c badly infested noth- ing can be done to save that particular tree. Something can be done, however, to stop the spread of the infestation to other trees. Infested trees should be felled and barked and the bark burned before May 15. Something could also be accom- plished by the use of trap trees. As the insect breeds readily in felled trees, a few healthy trees felled in May or June near those infested would attract the beetles which would otherwise deposit their eggs in healthy trees. Later in the season, or before the following spring, the bark should be stripped off the trap trees and burned. (sjjlflltjlifr V ...vSf a FIG. 20. — Work of the western larch bark-borer (Tetropium velutinum). Section of bark of western larch: a,, Com- pleted larval mines in inner bark ; b, adult beetle ; c, larva ; d, pupa. Insects approximately natural size. (Original.) 1 1 mm. =5*5 inch. 346 YEAEBOOK OP THE DEPAETMENT OF AGEICULTUEE. THE SOUTHERN PINE SAWYER. (Monahammus titillator Fab.) Within recent years the States of the extreme south have suffered severely from cyclones and other windstorms. An immense amount of pine timber has been felled by these storms. In practically every case great damage has been done to the fallen timber by the southern pine sawyer over the entire area covered by the storm. It has been estimated that during the years 1906, 1907, and 1908 the pecuniary loss from this source in the Southern States was over $6,000,000.1 FIG. 21. — Work of the southern pine sawyer (Monohammus titillator). Section of trunk of storm-felled longleaf pine, showing : a, Egg pit in bark ; 6, entrance hole of larva into wood ; c, pupal cell ; d, emergence hole ; e,