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LARA Tene ORD naa een eo nre ALLE ARO IE EA EACLE ere ccgersecsccesere. : Panes mer nnr ms pemme tm opaponae ae sn pl hari nh n= Arn mlooa U. S. NATIONAL MUSEUM LIBRARY OF Henry Guernsey Hubbard Eugene Amandus Schwarz 4 DONATED IN 1902 La? , > ae Ae Ke y t revit eS tye v SIXTH ANNUAL REPORT OF THE ENTOMOLOGIST OF THE State Experiment Station OF THE University of Minnesota TO THE GOVERNOR FOR THE YEAR 1900. BY OTTO LUGGER, PROFESSOR OF ENTOMOLOGY, UNIVERSITY OF MINNESOTA. ST. ANTHONY PARK, MINN., DECEMBER 1, 1900. McCGILL-WARNER CoO., PRINTERS, ST. PAUL. 4 o et a PP eb ye?, <> 1) YOET i ie WUBEUM FAK OTL LETTER OF TRANSMITTAL. STATE EXPERIMENT STATION, )} \ { UNIVERSITY OF MINNESOTA. DECEMBER 1], 1900. To His Excellency, John Lind, Governor of Minnesota: Sir :—In accordance with the law, I have the honor to present herewith my Sixth Annual Report as Entomologist of the Experiment Station of the University of Minnesota for the vear ending December 31, 1900. Very respectfully, Your obedient servant, Orro LUGGER FINANCIAL REPORT. 1899. No. of Vouchers. Amount Aug. 31. To salaries and labor for August, 1899........ 1-4 $120.00 ol = expenses paid by Di Schuetz. ..0-ccccecsssssese 5 6.15 31. ‘‘ trips to Madison, Pipestone, Mankato, Randolph, Owatonna, and New Ulm..... 6-10 24.90 31. “ bills of W. F. Lindig and Zimmerman 1 BFC) Syssandecacocools {doo SrivddadaadcesecadockioadcsosuDiooouaC 11-12 11.56 Gs ev Aiaty Pe LOA VIM SC Opes six sh onieectoeecéatvehwcsoaseses 13 32.00 Sls BMD LCIS ALC OX PEMSESs coecevc ccs seraesenece=s surste 14 6.25 Sept.30. ‘* salaries and labor for September, 1899... 1-4 125.00 RO ite MO WEN SER a sa educontesesctsescssussooueeeaeds sasvevaseuspnnee 5 2.60 30. ‘ trips to Madison, White Bear, Hinckley, Duluth, White Bear, Stillwater, Litch- HCL Gl car seeaetceaclicacaabsgoss Gosehencuon snsssactencsecs sas 6-9 15.90 30. ‘ bills of Zimmerman Bros., Noyes Bros., Art Engraving Co.......... Renee pesca seacenaedens 10-12 72.42 SOM eX PLESSI AN CEXDENSES s.: cccssceeodscsren secon eens ile 5.60 oO Mee OSLAL CS Gantt) Seccrscccsaarscosstrcscsacccraastocesisss: 14 15.00 Oct. 31. ‘‘ salaries and labor for October, 1899....... 1-5 157.40 Bite OG AWIG SS ANC CX PEHSES!...0: ‘oactod 168 Schizoneura tessellata Fitch (Alder-blight) ..... 170 Schizoneura lanigera Hausm. ( Woolly-louse of x0, Sub-family Aphidina (Typical Plant-lice).........cceseeeeseeeeee ones 177 Lachous dentatus Le B. (Toothed Willow ais] OUSe) rarcestceetececcnaes tesectsatqeacestnnwsaccermnas 1i7 \elanoxanthus salicti Harr. (Willow Grove Fe eatateMOSISE))acensccatece wcusstesscarechescesarestscnensciusees 180 Chaitophorus negundinis Thom. (Boxelder Jed Faye Kone Cra) ypenbsen gas nate noceeeeeCey Peep ECUOGOnCO ore e 180 Aphis cerasifoliz Fitch (Choke-cherry Aphis)... 183 Aphis crategifoliz Fitch (Thorn-leaf Aphis)..... 183 Aphis maidis Fitch (Corn Plant-louse).............. 184 Aphis maidi-radicis Forbes (Corn Root-louse) .. 184 Aphis brassicz Linn. (Cabbage Plant-louse)..... 185 Aphis rumicis Linn. (Bean Plant-louse)............. 188 Aphis mali Fab. (Apple Plant-louse) .............++ 192 Aphis prunifoliz Fitch (Plum-tree Plant-louse) 195 Aphis cucumeris Forbes (Melon Plant-louse) .... 196 Myzus cerasi Fab. (Cherry-tree Plant-louse)..... 198 Myzus ribis Linn. (Currant Plant-louse) .......... 199 Myzus persice-niger E. A. Smith (Black Peach- SSeS) Sed ackcs s dcedleveh rd cacaaduscutowssescedde: saenvesmends 200 Nectarophora viticola Thos. (Grape-inhabit- IM APUIS)) css. shubbaesaserececateacevncacenrdadveneesa=y-pes" 200 Nectarophora destructor Johnson (Pea Plant- LOUUSE) Sects seeeeee nee seeec cr asenemccectovsesessenscrseccnnees 201 Nectarophora avenex Fab. (Wheat Plant-louse) 202 Phorodon humili Schrank (Hop Plant-louse) .... 202 Remedies:against (Plant lice... .2.- .c-c.0.ceveutstaraccesceiaoosan>s4ieesesee- 204. ainily ALEYROID A? (Ale yrodes)..........c..sccceseenesssnesseecses secencoceaes 206 amily Coccm.® (Scale-insect, Bark-lice, Mealy-bugs) ......s...+ 208 Classification Of COCCIDAE...........c:cc00. cocsscsescveceessseeccceaes vnseee 210 Sibstatm ily COCCI AL. seecseac daca squocecesnaeaveses dedopeas scosseadassnnesaecaaes AL AL Dactyloptius species ( Mealy-bugs )......00..c0e+ cores 211 Dactylopiuscitri Risso (Common Mealy-bug).... 212 IRETMECIESeeree Nera teee cette races orcrae =< Jcensnneoaasnsdenetevocta-serssieceses 212 Pseudococcus aceris Geoff. (Maple Pseudo- COCCUS))sessec cease smectcracesedesncnsitecseusecescemsaqcsacenn. 213 Sub-farily Lecanina::....:.0-.00scvescsecessdascccevecsccconssaserssacese: nooase 216 ClassiiicaMonyOlmVeECa ia: suciosecteccsestccnvessccnastesc senses: 216 Lecanium cerasi.c:: Fitch (Cherry-tree Scale).... 217 Lecanium nigrotasciatum Perg. (Peach Le- GAMIMEMN oe teces senteuneta le teuaeeicerscarachavycesrseserseecess 218 Lecanium ribis Fitch (Currant Scale)................ 218 Pz!vinaria innumerabilis Rathy. (Cottony Seale) Maries sactvsstaces cauhestarennassoncestesdesdeeceel cosee- 219 xi. Sul family Dasma c. .-pkdas ceassle ss supa never pilaseeaateneae Vary meetin ee 223 Classifieation Of Dita spi icecjacwas sera’ sawsaadurdas setencysdageeenay 223 Aspidiotus nerii Bouché (Common White Scale) 224 Aspidiotus ancylus Putn. (Eccentric Scale of the Bln) pein ecectes cone peacrcnetseem cwecwescecccncoeeees 224 Aspidiotus perniciosus Comst. (San Jose Seale) 226 Diaspis rose Bouché (Rose Scale).............seseeees 235 Diaspis cacti Comst. (Cactus Scale).............002+. 235 Chionaspis furfurus Sign. (Scurfy Scale)........ 236 Chionaspis salicis Linn. (Willow or Cotton- wood Seaile)ij.cvc.t see cobacne sat sess sua Sbadosansentacs Zain Chionaspis americana Johnson (Elm-tree White SCALE); chasesbsalevte lesseccvecpeass seesaw asedsccces cose sarees 238 Chionospis pinifoliz Fitch (White Pine scale)... 239 Mytilaspis pomorum Bouché (Oyster-shell Bark-louserof. ple Apple) j<..5:4<.0s020eceissccdeansees 239 xiii INTRODUCTION. The sixth annual report of the Entomologist of the State Experiment Station of the University of Minnesota, respectfully submitted to His Excellency, Governor John Lind, contains an account of bugs found in Minnesota, which in their different stages are destructive to our various kinds of crops, and which frequently cause very great losses to the farmers and fruit growers. It was, however, impossible to describe all the numerous and destructive insects, belonging to the Order of Hemiptera, or Bugs, but as the species not described in the following pages are similar in shape and habits to those mentioned, it will not be difficult for the intelligent farmer to select the proper remedies against them. Remedies are given in every case and if applied a large amount of injury and consequent loss may be prevented. It would perhaps have been best to have the insects de- scribed in this report arranged according to their food- habits, but to make it also useful to students of our public schools, etc., the insects are arranged according to the classi- fication of Hemiptera usually adopted, and the different families have been described in a few words. The illustra- tions will assist greatly to discover the name of the culprit, so that those interested in such matters will find it easy to consult other publications to learn more about their habits, etc., as could be given in one report. There remains for the Entomologist the very pleasant duty of expressing his sincere thanks to all persons that have aided him in many ways in his work. Especial thanks is due to His Excellency, Governor John Lind, who always took great interest in the work of the Entomologist, and also to the different newspapers, who with unfailing court- XIV. esy, published all articles written for the instruction of the farmer in regions infested by injurious insects. The Chicago, St. Paul, Minneapolis & Omaha, the St. Paul & Duluth, the Northern Pacific, the Minneapolis, St. Paul & Sault Ste Marie, the Minneapolis & St. Louis and the Great Northern Railroad Companies also deserve thanks for their liberality in furnishing free transportation over their roads whenever such was asked. The descriptions of many of the insects given are taken from a number of sources, but mainly from the excellent works of Uhler, Comstock, Smith, Forbes, and others, and from the publications of the Division of Entomology, De- partment of Agriculture. Many of the illustrations were kindly loaned by Dr. L. O. Howard, of the above division of entomology, and by other gentlemen whose names appear below them. Miss Lillie L. Howenstein, under the guidance of Mr. Chittenden, made most of the original illustrations, and deserves much credit for her artistic work. The Art Engraving Co., of St. Paul, prepared many of the illustra- tions for the printer, and deserves credit for the good work. OtTtro LUGGER. Pte MIP LERA OR BUGS DESTRUCTIVE IN MINNESOTA. BUGS (Hemiptera) LV IRVOUS TO OUR CULTIVATED SPLANTS: OTTO LUGGER. The destructive species of Butterflies, Moths, and Beetles found in Minnesota have been described in previous reports, and especially have those been mentioned which are injurious to fruit- producing plants. In every -case a description and an illustra- tion of the culprits was given, as well as the best remedies to counteract their injuries or to prevent entirely losses caused by. them. In this report “Bugs” will be considered in the same manner, and to make the report of greater value to farmers and students, the insects belonging to the order of Bugs (flemiptera) will be arranged in such a manner as to indicate their classification as usually adopted. To do this more thoroughly a few only moderately injurious as well as some beneficial species have been included, for it is wise that the fruit-grower and farmer should not only know his enemies, but also his friends, as this knowledge will enable him to combat the former and to protect the latter. ORDER’ OF BUGS, PLANT-LICE, BARK-LICE ETC. (Hemiptera). The perfect, adult, or winged members of this order of in- sects possess four wings; in one sub-order, (Heteroptera), the first pair of wings are thickened at the base and have thinner extremities, which overlap on the back (Fig. 1); im another sub-order, (Homoptera), the first pair of wings are of the same thickness throughout, and usually slope at the sides of the body (Fig. 2). The mouth-parts are formed for sucking, (Fig. 3), and the metamorphosis is incomplete (Fig. 4). 2 BUGS. The Hemiptera comprise the insects which are properly called bugs. This term, as commonly used, is applied to any- thing that creeps or crawls, but the entomologist always refers to a member of the order of Hemiptera when he speaks or writes of a bug. In the order are included such insects as true lice, bark-lice or scale insects, plant-lice, tree- or leaf-hoppers, stink- bugs, chinch-bugs, bed-bugs, electric-light bugs, and others. Many of these insects are very destructive, and annually cause heavy losses to the fruit-grower and to the farmer. Others are Fic. 1.—A heteropterous insect (Nezara Fic. 2.—A homopterous insect (Ormenis pennsylvanica De Geer), with crossed pruinosa Say); a, with wings expand- wings. Original. ed; 6, with folded wings. Original. beneficial, as they destroy numerous injurious insects, while still others, as the cochineal and lac insects, produce useful materials. The name Hemiptera, which has been selected for this order, has been derived from two Greek words: hem1, half; and pteron, wing. It was suggested by the form of the first pair of wings in the true bugs, where the basal half is thickened, resembling the wing-covers of beetles, and where the abrupt terminal half is quite different, being delicate and wing-like. The second pair of wings is thin and membranous; they are used for flight, and are folded beneath the first pair of wings when at rest. -The BUGS, i upper pair of wings are frequently called wing-covers, or heme- lytra, a name suggested by their structure. The wing-covers furnish characters of importance in classifi- cation, and for this reason special names are given to the differ- ent parts. The thicker basal portion is composed of two pieces joined together at the sides; one of these, called the clavus, (cl.), is narrower, and is the part next to the scutellum when the wings are closed, Fig 5; the broader piece is the corium (co.). In some families a triangular piece of the terminal part of the corium is separated as a distinct piece, which is called the cuneus, (cu.) ; in other cases a narrow piece on the costal margin of the corium is separated, which has received the name embolium, (e.). The softer terminal portion of the wing-cover is called the mem- Fic. 5.—Venation of an upper wing of a heteropterousinsect. Original. brane, (m.). All wings are strengthened by veins, which have also received special names not necessary to mention in this report. There are a number of degraded forms of bugs, degenerated because leading a parasitic life. In these cases, as in the true lice and in the bed-bugs, the wings are not developed, nor would they be of much use to the insects. In fact they would be de- cidedly harmful in the case of the bed-bugs, who in sparsely populated regions, after leaving one host, would not be likely to be able to find another one. But in cities wings would be a great improvement for bed-bugs, though a step in the wrong direction as far as man is concerned! In some species of aquatic bugs we find adult individuals entirely unwinged, half winged, and with fully developed hemelytra and wings. 4. BUGS The mouth-parts (Fig. 3) of all bugs are formed for piercing and sucking. They appear as a slender jointed beak, starting at the base of a shorter pointed upper lip or labrum. But this beak or rostrwi, usually composed of four joints, never more, is simply a horny, jointed, and tapering sheath, enclosing the true and real mouth-parts. If we dissect the beak, or rather remove Fic. 3.—Mouth-parts; a, of Reduvius, from side, after Smith; b, of Notonecta, after Miall; c, of Bed-bug, original; d, of Aphis, after Smith. it entirely, we can detect four bristles, two of which represent the mandibles, and two the maxille. Maxillary palpi are want- ing. The four bristles are adapted for piercing the tissues of plants, or the skin of animals. Sometimes the beak is very long and slender, or it is short and thick. The length of the beak depends upon the food-habits of the bug, whether it has to probe deep into the plants, or finds liquid food near the surface. BUGS. 5 By means of contractile muscles the liquid nourishment is imbibed. We find, as a general rule, that bugs living upon the sap of plants have a long and slender beak, while those imbib- ing blood have a stout and shorter one. The sternum is so modified that it coincides with the form and use of the beak, since it has to support the movements of the head and its organs. The Hemiptera are either aerial, terrestrial, riparian, or aquatic. Some live high up in trees, others on the lower limbs and trunks; still others are found among the roots and rubbish on the ground. Many hide among the foliage of plants, among FIG. 6.—Different legs; a, grasping claw of Hog-louse; b, grasping front leg of a Soldier-bug. c, ditto of Phymata. Original. grasses and herbage, while others skim over the surface of placid waters, or swim below it, coming to the surface only to breathe. A few are found even remote from land, upon the quiet waters of tropical and sub-tropical oceans. But in all cases their legs are adapted to their mode of locomotion. Some are fitted for leaping, others for running and creep- ing, and still others for grasping tightly to the objects upon which they rest. Those that creep about in search of living prey are often furnished with curved or hooked fore-legs, suit- able for seizing and holding creatures when in motion, such as caterpillars and other larve (Fig. 6). The anterior femora of 6 BUGS. many kinds which move about on branches and leaves of trees are set with numerous sharp thorns, sometimes in opposing rows; with them they transfix and hold their victims. In the tropics there are many forms in which the hind legs are not alone simply flattened, but are flattened to such an extent as to be transformed into veritable sails. “The head is either somewhat flat above and extended for- wards nearly in the plane of the thorax, with the eyes seated in or next the base; or it is spindle-shaped, long conical, or cylindrical, freely movable, with the eyes placed considerably in advance of the base. In most riparian forms the eyes stand out prominently from the corners of the broad forehead. The aquatic species have the eyes either deep-seated in the basal angles, or projecting like beads on the sides of the vertex. In the Corisz the head overlaps the front of the thorax like a cap, and is there attached by a slender neck, as in Diptera and dragon- flies. Strongly in contrast to all these we find in the principal Homoptera a head either transverse or vertical, deep-seated, im- mobile, and prolonged downwards and backwards. In such ex- ceptional groups as the Fulgoride, the front of the head is either drawn out into a large inflated protuberance, is curved forwards in a long, tapering horn, or it is shaped like an Indian war club. Two, or at most three, ocelli are generally present; but they are absent in certain groups. “The thorax constitutes a large portion of the mass of the body, and its first principal division is generally free, as in the Coleoptera. All three sections of this part of the body, the prothorax, mesothorax, and metathorax are well distinguished, and are only“fused together in such low forms as Aleurodes, Aphide, Coccide, and the lice. “To these three pieces the legs are attached, not far out on the sides, as in Orthoptera and Pseudoneuroptera, but beneath, and generally near the middle line. They are fitted for running, jumping, grasping, or swimming; and are often provided with curious balancing plates, curved thorns, waved lamelle, or rows of spines. The coxe are also built upon two principal patterns ; the one being more or less conical and rotatory, the other more elongated, fixed, and only capable of motion in the direction of BUGS, G the longitudinal axis of the body. The tarsi have generally three or two joints, rarely only one. Generally there are four wings present, but the posterior pair does not appear in the males of the Coccide. The hemelytra and lower wings are developed from the sides of the meso- and metathorax; and in the Homop- tera they are generally attached lower down than in the Heterop- tera. “A system of tracheal vessels conveys air to all parts of the body, and communicates with the outer surface by means of openings called stigmata. These openings are provided with a lid or contractile fold, which can be tightly closed to prevent suffocation. In a few of the aquatic forms, Belostoma, Zaitha, etc., they are apparently closed, but in reality have slit-like or valvular orifices which serve to strain the air and perhaps to admit only the oxygen that it contains. An air-chamber gener- ally rests beneath each stigmata, and is connected with the others by tracheal tubes running throughout the length of the body on both sides. The stigmata amount in all to ten on each side; a pair is placed on the underside of each of the three divisions of the thorax, generally on or near the transverse sutures; six pairs are set beneath, on the sides of the abdomen, and a pair is placed above next to the suture which separates the thorax from the abdomen. In Fulgora and its near allies the latter are very large, but are covered with a whitish fibrous secretion in the living insect. In the higher Heteroptera the abdominal orifices are capped by a little prominence resembling a bead, while in Notonecta, Corixa, and some Cicadas they are concealed by fur, hairy filaments, or scales. Fanatra and Nepa possess the usual number of stigmata, but have in extension a pair of long respira- tory tubes at the end of the body through which they appear to receive most of the air required. “A variety of fluids and other substances are secreted by the Hemiptera. Some of these are for the protection of the body or the eggs, as in the Coccide; others, perhaps, for de- fence, as the annoying spray emitted by most of the Heteroptera. In many of the latter a most offensive bug-odor is characteristic - of the fluid secreted by glands situated generally in each side of the body behind the mesosterum. Each of these glands com- 8 : BUGS. municates exteriorly with an orifice placed behind or near the middle coxa, called the osteole, which generally issues in some kind of an open channel styled the osteolar canal, and this is surrounded by a more or less rugged and granulated space, the evaporating surface. The secretion is an ethereal oil variously combined, speedily dissipated in the atmosphere, and often hav- ing an odor similar to that of pears and other fruit. In some species of Coreidz it is decidedly aromatic, and in a few it has a spicy smell very much like that of cinnamon. “These organs appear to be absent from the Homoptera; but most Cicadas secrete a powdery substance, scales, or hairy patches from the under side of the body, while the Fulgoride become covered beneath and on the end of the abdomen with a cottony or fibrous white substance. Some of the Coccidz secrete wax or lac, and others various kinds of valuable dyes. The functions of nutrition are performed by a well-defined system of organs, of various forms, and often of remarkable complexity. Behind the mouth a short, distinct throat receives the fluid from two pairs of ducts connected with the salivary glands. From this the stomach is continued by an intestine-like tube, swollen in two or more places, until it reaches the vent. The first stomach, or gizzard, is a large, straight, frequently constricted glandular sac, narrowed behind into a long flexed or convoluted canal (duodenum), also glandular, and dilated posteriorly into the chylific stomach; this is often continued backwards as a slender intestine (ilium), emptying into a colon-like expansion that terminates with the corespondingly wide rectum. Both of the intestinal parts of this organism are sometimes reduced to mere peduncles of the three pouched dilatations. “Most of the eggs of the higher Heteroptera are ornamented with bands, or other patterns of color, and many of them are fluted, beaded, ribbed, ete. They are also capped by a toothed and movable lid, provided with a ligamentous spring to aid the emergence of the larva. (Some eggs are shown in the illus- trations showing the various stages of these insects.) The num- ber of eggs laid by a single female varies also, not only with the species, but in the individuals. Some have been known to lay as few as twenty-five eggs, while the female Cicada sometimes deposits more than five hundred. BUGS. 9 “Although these insects are not so numerous in species as the Coleoptera, Diptera, or Hymenoptera, they far outnumber the Orthoptera and Neuroptera, and possibly also the Lepidop- tera. A large proportion of them have sober colors, agreeing well with bark, earth, rock, or other surface upon which they rest, and multitudes are easily overlooked because of their close resemblance to buds, processes, scales, and other objects that surround them; it is these peculiarities which have caused them to be difficult to recognize and have retarded their acquisition. But with the spread of more exact knowledge of their habits, a new impulse has been given to the study of the species, so that every expedition to unexplored regions returns with a quota of previously unknown forms. ca Fic. 4.—Stages of growth of atrue bug. Original. “Their metamorphosis (Fig. 4) is incomplete, excepting only the males of the Coccidze and a few forms closely related to them. After leaving the egg they generally change the outer skin four times, at intervals of a few days each, to become adults. Growth is thereby permitted, the wing-pads and body become one size larger, and there is only a slight difference to be noticed be- tween the young and the perfect insect. Nothing like the cater- pillar stage appears in the newly hatched creature, and there is no such differentiation as marks the larva, pupa, and imago of Coleoptera and the higher orders. The next stage to the adult is commonly called pupa, or nymph, but not because it is in any true sense equivalent to the pupa of other insects.”— Uhler. There are few great groups of insects that display such a wide range and diversity of structure and consequent habits as the Hemiptera, and for this reason it is rather difficult to give a classification. By some authors the order Hemiptera is 10 CLASSIFICATION OF BUGS. divided into two orders of equal rank, but whether much is gained by this operation is doubtful. It seems best to divide it into three well marked groups or sub-orders. Prof. Comstock, who has given much thought to this group of insects, places the: Heteroptera first, because they resemble the ancient Hemiptera— the first to appear on the earth—more closely than the members of the two other sub-orders. He places the true lice next. These are very much lower in structure than the Heteroptera, but their simplicity of structure is the result of degradation due to para- sitic habits, hence represents a later development. They are probably descendants of some ancient form resembling some of the existing Heteroptera. We see in the bed-bug, an undoubted species of Heteroptera, a similar downward tendency due to its parasitic mode of life. The Homoptera, including no doubt also some very primitive forms, show the widest divergence from the hemipterous type. The three sub-orders can be separated by the following table: BUGS. (Hemiptera. ) A. Wingless Hemiptera, parasitic upon man and other mammals, with a fleshy, cmjpomtedeheak.