OF MINNESOTA 4 =o "7 J — TO THE GOVERNOR RICULTURAL EXPERIMENT STATION ST. ANTHONY PARK, MINN. ‘DECEMBER, 1910 _ . nag) eee THIRTEENTH REPORT OF THE STATE ENTOMOLOGISI OF MINNESOTA TO THE GOVERNOR FOR THE YEARS 1909 AND 1910. SEVENTH REPORT OF F. L. WASHBURN. AGRICULTURAL EXPERIMENT STATION ST. ANTHONY PARK, MINN. DECEMBER 1, 1910. PRESS OF H. C. BOYESON CO. Sarnt PAUL LETTER OF TRANSMITTAL STATE EXPERIMENT STATION, St. ANTHONY Park, MINN., DECEMBER I, IQIO. To His Excellency, A. O. Eberhart, St. Paul, Minn. DeEaAR Sir: I herewith present the Thirteenth Report of the State Entomologist of Minnesota, covering work of this office and insect conditions during 1909 and 1910. For the sake of economy this report is now printed biennially. In addition we print from time to time and mail to farmers and fruit growers circulars of information and press bulletins, planning to have these reach them at the time when most needed, and thus be more helpful than if we delayed publishing until the issuing of the printed report. This plan appears to work satisfactorily. GENERAL INSECT CONDITIONS DURING 1909 AND Ig10: Dur- ing 1909 native species of grasshoppers were abundant and trouble- some in various localities throughout the state, complaints reaching this office from St. Cloud, Fertile, Crookston, McIntosh, and from localities in Otter Tail and Norman Counties. These complaints were prophetic of the trouble in store for us in rg1o, the present year, in which grasshoppers have been more troublesome, causing decided loss locally, than for many years. These are native varie- ties, and while they have not possibly noticeably reduced the yield of grain, in the state at large, they have, in certain localities, cut down the crop of farmers from two-thirds to four-fifths, some individuals having become utterly discouraged in consequence. The output of flax, however, has been markedly diminished this year, which diminution is due almost entirely to the attacks of grass- hoppers. Where practicable your entomologist has helped deserv- iV ing farmers by furnishing them oil for use in hopperdozers. The furnishing of free oil, however, is too great a tax upon the slender resources of the State Entomologist, and cannot be continued unless some more material financial aid is granted by the state. It has been suggested that a grasshopper emergency fund be created, and kept upon the State Auditor’s books for use in times of crisis. The trouble has come, in every case, from the existence in the neighbor- hood of large tracts of unused or reverted land, held by residents or non-residents, who either cannot or will not cultivate the same. The subject of grasshoppers, and the need of a more stringent grass- hopper law is discussed elsewhere in this report. The greatest damage which came under our observation occurred in Wilkin County, though Polk, Clay, Norman and other counties also suf- fered.) See page 10; Cutworms have been so abundant and injurious during the spring of 1910 that we have made them the subject of our colored plate. Later in the season the wheat head army worm, Heliophila diffusa, appeared in enormous numbers in about thirty different localities, and not only destroyed the seed of timothy, but injured this crop for hay, and in many cases marched to neighboring crops, causing wide-spread havoc. This pest, which is very rarely trouble- some, originated this year in Minnesota in timothy fields which had been allowed to lie too long unplowed. The army worm cited has been so injurious that it is made the subject of a special article in this report. See pages 1 and 4 and figures 1, 2 and 3 on colored plate. The annual visitation of the different kinds of grain lice was in evidence in 1909, not resulting, however, in any serious injury. No complaints have reached us of the Corn Root Worm which, however, 1s so abundant and injurious in Iowa that Professor Holden, of Ames, Iowa, reports that the 1910 corn crop of that state was damaged to the extent of $20,000,000. Shade trees have suffered both in 1g09 and 1910 from the pests common to them, and the year just closing is noteworthy on account of the quite wide-spread destruction of some of our finest city trees. Elms have been killed by the elm tree borer, and maples attacked in many cases and ruined by one or more species of Buprestid beetles which affect such trees. Both in 1909 and 1910 the Oak Pruner, the Fall Web Worm, the White-marked Tussock Moth, the Locust Borer, Bronze Birch Borer, Birch Leaf Skeletonizer, and Leaf Folders have been in evidence. (See page 103.) The usual quota of fruit tree pests has been noted, and the increase of two scales, namely, the Oyster Sheli Scale of the apple, and the Scurfy Scale, is particularly to be remarked upon. The Buffalo Tree Hopper and the Apple Leaf Hopper have also been the subjects for complaints. We also have to report complaints of serious injury from the Strawberry Weevil. We are beginning to receive inquiries regard- ing the Onion Maggot and Onion Thrips. Buffalo Gnats, “Black Flies,” were very bad in the spring of 1909. A typhoid epidemic occurred in towns on the Minnesota Iron Range in the fall of 1910, and your entomologist was called upon by members of the State Board of Health to visit the localities in question for the purpose of aiding them in determining to what extent the common house fly, or Typhoid Fly, as it is now called, was responsible for the spread of the disease. An abstract of our report on conditions there, with photographs, is printed on pages 135-142. SPECIAL EXPERIMENTS: Under the direction of the Office of Experiment Stations at Washington we have been working in 1909 with the Apple Leaf hopper, above mentioned; also a grain insect, Macrosiphum granaria, and a clover insect, B. funebris, which reduces the yield of clover seed. Special experiments also have been conducted against the Cab- bage Maggot, which attacks not only cabbage but cauliflower, radishes and turnips; against several species of stalk borer very destructive in gardens, and spraying apples and plums to prevent injury by plum curculio. We have also tested the possibility of poisoning fruit trees by the use of arsenical sprays. Our special work in 1910 in the line of experimentation has been the study of the clover seed midge, known as Bruchophagus funebris, an insect which lowers our product of clover seed ma- terially every year, probably from 40% to 50%, and whose life history is not fully understood. In this connection we are working under the direction of the Agricultural Department at Washington, and have made considerable progress in our knowledge of its habits, which knowledge will help us in combating the pest in this state. We have also carried on special experiments with various insecticides, and are beginning work with the Wheat Joint Worms. V1 INsECTARY: Three hundred and fourteen different experiments were carried on in the insectary during 1909. This number repre- sents a large series in connection with the clover seed insect, referred to above, and also the leaf hopper. There has also been insectary work with the Stalk Borer, several species of borers working on shade trees, and many insects have been reared from the larval to the perfect stage, thus giving us an opportunity of studying their life histories and determining their names. Two hundred and fourteen insectary experiments is the record for 1910, which really represent a much larger number included as “sub-experiments.” EXPERIMENTAL GARDEN: A piece of land granted the ento- mologist for experimental work, upon a part of which the insectary is located, has again demonstrated its usefulness, and the director and a committee for the purpose has allowed the entomologist some land adjoining the present site for future work. The entomologist has been promised sufficient land for experimentation, should the present garden be needed for building space. SPRAYING EXPERIMENTS: ‘The assistant entomologist, Prof. A. G. Ruggles, carried on in 1909 a number of experiments in spraying, and in summarizing the results of the work, it may be said with certainty that three sprayings for plums and apples, with three pounds of arsenate of lead in fifty gallons of Bordeaux mix- ture, the first spraying to take place before the fruit trees bloom, the second just after the bloom has fallen, and the third ten or twelve days later, will insure a very large per cent of sound fruit, protecting the fruit and the tree from the attacks of the Plum Curculio, Cod- ling Moth, and also a majority of plant diseases. See page 143. The crop of plums and of apples was practically a failure in Ig10, and we have, therefore, been unable to push work further in this direction. STATE INsEcTIcIDE Law: At the thirty-sixth session of the State Legislature a bill, (H. F. 173) for an act to prevent deception in the sale of Paris green and other insecticides, introduced by Mr. Horton, became a law. The enforcement of all provisions of the act was placed with the State Dairy and Food Commissioner. A federal law to the same effect, but including all states and terri- tories was created by Congress in the same year. The latter also imposes several penalties for the shipment of any adulterated insecti- cide or fungicide. See page Iot. Vil CORRESPONDENCE: During 1909 the entomologist dictated 2,149 letters, in large part answers to inquiries regarding insect pests. In addition 774 circular letters were mailed, and about 2,000 circulars and press bulletins, exclusive of the station mailing list. This does not include the Twelfth Report, which was sent out to approximately 700 addresses in addition to copies mailed to comply with individual requests. Bulletin 112, which was practically a duplication of the Twelfth Report, was sent from the Experiment Station mailing office to something like 15,000 addresses. In 1910 we mailed 2,461 letters, answering inquiries, in addition to over 1,000 circulars. Lectures: In 1909 a few lectures were given by the entomolo- gist in the northern part of the state (notably one on December Ist to farmers at Red Lake Falls) in regions which had suffered that year from attacks of grasshoppers. In Ig10 one lecture was deliv- ered January 14th at Duluth, and lecture appointments for the next eight weeks have already been made, as follows: December 6th, State Horticultural Society, Minneapolis; December 12th, Boy Scouts, Minneapolis; December 21st, Agricultural College, Crooks- ton; December 28th, Entomological Society of America, Minne- apolis meeting; January 21st, Boys’ Club, Minneapolis. Lectures were given, both in 1909 and Ig10, to students in the Farmers’ Short Course at the Agricultural College. Publications. —1909— Jan. 20—“‘Cabbage Maggot on Radishes, Work of 1908.” Feb. 12—Twelfth Report of State Entomologist, ““‘The Apple Leaf Hopper and Other Injurious Insects of 1907 and 1908”. Feb. 20—Circular No. 16, “San Jose Scale Possibilities in Minnesota”. May 4—Press Bulletin 31, reprint, “Suggestions to those contemplating spraying’. May 25—Circular No. 17, “Household Insects: A, The House Fly and the Clothes Moth”. Nov. 15—Circular No. 18, “The Museum of the Division of Entomology at the Minnesota Agricultural College’, —1910— Feb. 1—Circular No. 19, “The Danger of Introducing the Gypsy and Brown- tailed Moths into Minnesota’. April —Nine thousand insect charts. Vill June 1—Vol. 1, No. 1, Minnesota Insect Life. July 1—vVol. 1, No. 2, Minnesota Insect Life, Aug. 1—Vol. 1, No. 3, Minnesota Insect Life, Aug. 25—Press Bulletin No. 39 (Circular No. 20), “Grasshoppers and Army Worms in Minnesota”’. Sept. —Pamphlet descriptive of figures on chart ‘‘SSome Minnesota Insects and Useful Birds”. Nursery INSPECTION: In 1909 sixty-two nurseries were inspected ; the sum of $234.74 collected as legai fees and expenses was turned into the State Treasury, according to law. In 1910 fifty-eight nurseries were examined, much more time being spent on each nursery than in the preceding year. The sum of $263.73 received, was handed the State Treasurer, and receipt received therefor. See page 59 for detailed account of inspection of nur- series, INSPECTION OF STOCK IMPORTED FROM EuROPE INTO MINNE- SOTA. See page 59. InNsEcT CHarts ISSUED BY THE STATE ENTOMOLOGIST TO THE PUBLIC SCHOOLS OF THE STATE. See page 123. SAN JOSE SCALE. See page 67. Insect CoLLecTIons; HyMENOPTERA OF MINNESOTA: Our collection of Minnesota insects has been materially increased this year, and we have made a special effort tc secure a systematic col- lection which will aid in a popular treatise on the bees, ants and wasps of Minnesota planned by this department. “MINNESOTA [NsEcT Lire”: This publication is a new feature of our work. It aims to place before farmers and fruit growers of the state timely items on the prevention of insect injury during the spring and summer. The mailing list of this publication is growing constantly. It is in no sense a bulletin. We issued this year three numbers—one on the first of June, one on the first of July, and one on the first of August. We aim, in future, to mail the first copy not later than April 1st, which will, among other things, give our agriculturists proper information regarding spraying. Exuipits: In March, 1g1o, at the first State Conservation Congress, held in the Auditorium at St. Paul, this division displayed an instructive collection of insect models, illustrations of insect injury, life histories, spraying machinery, nozzles and insecticides. The entomologist was in Europe at that time, and the exhibit was prepared and installed by Assistant Professor Ruggles of this department. We also had, as in previous years, exhibits at the State Fair both in 1909 and Ig10. Honorary OFFices: During 1909 and 1910 the Minnesota Entomologist has held the office of President of the American Association of Horticultural Inspectors, and has recently been hon- ored by being elected President of the American Association of Economic Entomologists for the ensuing year. ACKNOWLEDGMENTS: The work of the past two years has been materially helped by the faithfulness and efficiency of my office force and field assistants. I wish to express my appreciation of their loyalty. J] have lost one good man in Dr. Franklin, who resigned to accept an extremely flattering offer in Massachusetts. His place has been filled by Mr. Theodere Urbahns, formerly in Government service, who comes to us with excellent recommenda- tions. Mr. A. G. Ruggles is still with me as chief assistant. Mr. E. W. Stafford has been employed in the insectary. The state press, as always, has been helpful in placing before the public timely notices regarding insect pests. While this department does not hesitate to publish what it deems important, we greatly deplore the practice prevalent among many reporters of writing up ficticious “scares” for the sake of making good stories. As exhibiting the help of the press 1n connection with our work, and also showing in what demand publications from this department are, when it is generally known that such publications are for distribution, this office received, after inserting notice of publication in various county paper, but by no means in all, over five hundred requests for a bulletin on spraying, within a period of six weeks. In connection with our inspection of European nursery and florist’s stock sent to this state, the collectors of U. S. Customs, both at St. Paul and Minneapolis, have been very helpful in that they have notified us immediately upon the arrival of foreign shipments. See page 59 Finally, I wish to thank you, Sir, as well as others at the State Capitol, for most courteous and kindly treatment in connection with the work of the entomologist. Respectfully, EF) Ln WASHBURN. FINANCIAL STATEMENT,* FISCAL YEAR, AUGUST 1, 1908, TO AUGUST 1, 1909. ANIA SIS IND DIVES san) ya a aieraysialer ete Cake aes a ores ic ais ae ence eRe $ 15.99 ASSIST AM teh ntOMOLO Si Sta (salanys) ma eneeieeinnie ecieierieiciien ete 466.64 Clerk and accountant: ns )-resreioc ie csese tetas eis cae cirstelersecoreecisse 400.00 Cuts, etchings, electros, colored plates, ete., for Annual Reporte DuUlletins andacirculansmrnemeeem einer 423.82 Drawings, etc., for reports, bulletins and circulars ...... 79.49 Dxpenimentalscandentesiipplicsm assent cenit 104.99 HVcldSnoOtes Mone IMISCCUSs” koein isis ce eneie eter tones) ines ose 25.41 Field and traveling expenses of Assistants.............. 207.73 Mrerehtwand express: ict te sci ators eines Reason ste ienn ee 73.62 ImSectary a pPAaratus) se seine cisco asvenanstcisic toon terion asin tae aoe 26.55 Inmsectanrya and stield assistants! eerie Cie oe eicie 364.36 MMSE CTI GLASS oi eda 5 ct eee TO aoe OR NE cons ech eee 33.87 Efi) 070) Deane eeaire ene tiers St ae Une cre be at ie Seen ALS 2 A SR ale ge eae 152.99 Mahoravonye SuUppWesm andarapparatuse sereereiieeieee ence 82.07 Microscopes (Greenough dissecting) for imsectary ...... 222.00 Models of insects for lectures, and insect cases.......... 42.50 INUIESERYyANSPeChOnmeXpPeNSCSmen eee sien 214.91 OficevandMaboratonysassistants ease seen 306.90 OMicessupplies anid hummi shin Seances ene interne nee ri Periodicals, publications, library cards, et¢..:............ 147.31 Photessupplies sek Siseher chk atl Oo ee oe eee 75.99 Rlantseionwexpenimentialmcand Cnie ire ania eieE irra 49.90 Postage Correspondence, Biennial Report Circular ...... 156.00 Prinniniss yA nial report. ClnCuUlaGrsmetGssnenairnireiecreree 1,008.25 Sprayine’® machinery, Favs csc the ee oie a ee ee ee 18.00 State Entomologist’s traveling expenses ................ 156.47 Slatvlonanycetey saat shiek Wak ced. Parte ee eee SL BAS SWHOSHNGDINE EMSINO ACNE oocoonocdanoeooncuocsndecosoooL 22.50 Meleerams) syo.c.8 bons eat ee eee oe ee ee ee 13.08 MOE PWOME' .. x ia.5cle oust ae exces wi abe Oe of te EO eee 65.00 Credity NUESEYenInSpeCtlO nu eee erieen reer ien errs EHCOMOLOS1Sit.Si SRV eee ree eee $ 214.91 5,000.00 $5,122.46 $5,214.91 Balance.ony hand: 255 eco. he cone nee ee ene $ 5,122.46 92.45 *Bills covering details of the above are on file in the State Auditor’s Office. x1 FINANCIAL STATEMENT* FICAL YEAR AUGUST 1, 1909 TO AUGUST 1, 1910. ASTUTEDTAY? | ng SRS RG olore ne RIE Or ISLC SCR RRC UR RET CR ME RPE Hen eT att aI RPRCIS S 13.25 Assistant sHmtomologist (salany)). cso occ. ece as ee dacs 1,649.99 Assistant Entomologist, (Traveling expenses) .......... 70.32 ASSISTANT Ine MeGeral Imspection: ... ck. ce. + «oes sce e cess 135.00 Cuts, etchings, etc., for Press Bulletins and Circulars .... WIRY) Drawines torenepe DUIS: circulars: "ete ..ce..c.cec- + se cece 35.00 PRESS ECTS NG falecr vcleuctereetensheretere cron cueters Ge oe aleyalavele. 40.82 sel Climvy Oss Kernen reteyoiiet ars eieia svexecratotoere ccs oiaie sineks cars cle wide amnens 36.50 Insectary assistant (field expenses) .................... 104.60 iMmsectany chieh (fieldiiexpenses)) J22....6...+00s00veeces eels 84.55 MT SCCLAR Ven SUD DIGS arartartaieseteracte cic) s@ wits ew cle palscae si viee che as 30.02 IGSCCUCIC CS meat yore barrens See ein wielais sachetsveye cuss. ejand ate onahe 33.54 Kerosene for combating grasshoppers .................. 6.00 ILE OGLE” » BiB cesta Gre clo Uttyd C Dinec CREO OR NG cee ee ee eee ee 131.47 WAU OLATORYeSUP DIES) sxiiccictctieiaisrsoe cod eloles alee s/o elie vece ere are eas 203.03 Ap ULINN LD CT ese rer ane Cena cttee xe ora) a ch oters oueraisasyek che, baile) ASME oe ation here shinee dete 8.56 INTIES CI yam SP ECCULOMN Ns a:c-etvtes e-cnsrelsietede. sits euehera cteualscsiel ete arese a s0as 202.31 TT COMASS IS TAMULS tery folspeleyercret rece. cue eue costo shat ols lal tomel a ousteder Shaver chine 552 ICOM SUD DTC S ie ey nosey rere sees ssoreerereke cua le robs olen ertoee oy win Secs eas ana 32.35 MOLOSSSHELALLVES: sPTIMUS, (6tCicccs ocacc ciiees sell siete cm weve 33.79 Tatas Ome alte CM assy aces orcas eens rereeen stro teme teceyfatleik eel a unserer eae avers 52.85 BrnbtinesCbpulletins, circulars; Cts). oc... e260 a0 cies ere 44.75 Publications, periodicals, press notices, etc............... 109.24 SECRCUA Type IN CN GLET Ki span ert hic, sitions leudterehe miele Sues 2 sponge eee ote 1,001.00 SD evs Sena INTVETY Sa rey.c) aires cic sieteuerst henarcomis aie to cenare © aacsiarsi one 311.00 Stamps for correspondence, circulars, etc............... 69.00 AGL OMI Vater es iolred epee lsiate iersea ta Acree nerateroin sai vie yossiotorainmareee = 103.58 SupStimuremstenosmapnenr vans sees lasses eee sees cs les. 10.00 AUST ATES. SEM ere Bee ol ccas ce tea RS oO TN ee ee en eee 18.59 PEIEDINODE | As ORO ee SIS Oe CREE eee eee eer ee 60.00 PTAC MIM SAMO XI) CU SES! oss nyse hsvsrveteso seelel wile oi aie oy oie debevtae ac Sa 209.35 $5,003.07 Balanceson: hand Augeust 1) 1909) 20.6 sc eec ese cee 92.45 LEM UOTE LS apeectckey Comte hCnSiaLs COCCI tenance Uae tr EUR aaa | ARO de ee EEE $5,000.00 INTIS STARS DECEIONS eke tn ae Wy uote oi crele eros c aethek el aust cans Rooters 234.74 $5,327.19 5,003.07 ESB IDINCS OMe ANT Clas cee) ote, re) Papa ows os Reale oh ote Ma $ 324.12 *Bills covering details of above on file in the State Auditor’s Office. The above account has been examined by me and found correct. State Auditor. — —_ I. L,. WOOD, DEL BUR. ENGRAVING, MPLS. CUT WORMS, ARMY WORMS, AND OTHERS. INJURIOUS INSECTS OF 1909 AND 1910 BY F. L. WASHBURN. CUTWORMS. EXPLANATION OF PLATE: Figs. 1 and 2—Wheat-Head Army Worm, H. diffusa, Walk., much enlarged, and showing variations in color. Fig. 3—Moth of the same. Figs. 4, 5, 6 and 7—Different Cutworms, collected in the vicinity of St. Anthony Park; died before reaching maturity, hence not identified. Figs. 8, 9 and 15—Caterpillar, Moth and Pupa of Hadena devastatriz. Figs. 10 and 11—The Zebra Caterpillar, or Painted Mamestra and its moth, Mamestra picta Harris. Figs. 12, 13 and 14—Larva, Moth and Pupa of the Cutworm known as the Subgothie Dart, Feltia jaculifera. We are indebted to Dr. J. B. Smith for identification of the above imagoes. Riley’s account of H. alblinea probably applies to H. diffusa, the latter being commonly regarded as albilinea and was so figured by Riley. Cutworms, represented here by several species, have been so extremely troublesome in Ig1to, that we have made them the subject of a colored plate in this report, including also the Wheat- Head army worm, Heliophila diffusa, Walk, which has been locally very destructive, and also the Zebra caterpillar Mamestra picta, and its moth; which, while not a cutworm in the strictest sense, belongs to the same family, Noctuidae. The abundance of cutworms this year may have been due, in a measure, to the cold weather cutting down the weed growth which started in the abnormally warm weather of the early spring of IgIo, obliging them to turn their attention more completely to cultivated crops. Complaints of cutworm injury began to reach us in May of the present year, and a few letters were received as late as August. There were more than twice as many complaints in 1910 as in the preceding year, and among the localities affected were Brainerd, te INJURIOUS INSECTS OF I909 AND I9Q1O. Atwater, St. Paul, Ada, Hibbing, Hastings, Grove City, Kimball, Duluth and Sauk Center; showing the generally unusual distribution of these pests over the state. Several species were probably respon- sible for the injuries. Those shown upon our colored plates were, for the most part, numerous; but they by no means represent all the varieties present during the two past years. Two instances well illustrate the unusual abundance of this pest in 1910: A gardener in Minneapolis brought us something like fifty or sixty cutworms (species not determined at the time) which he had dug from the soil along a row of onions, not more than fifty feet long; while a member of our staff dug up from about a small piece of golden glow, not more than two feet square, last spring, thirty to forty cutworms. Cutworms are the larval forms of moths belonging to the family known as Noctuids, or Owlet Moths. The first name was given this family because they are particularly night-fiyers, most of them remaining concealed during the day; and the second name, on account of the fact that their eyes shine at night, in the presence of a light, to which, by the way, many of the species are attracted. Living normally in sod land, what could be more natural than that when deprived of this by farm cultivation, they should attack the crop immediately following. They may be, therefore, very severe on crops following sod. The larvae, like the moths, work at night, and conceal themselves, either in the ground an inch below the surface or under some protecting material, in the early morning. Both the moths and their larvae are fond of sweets; and this fact is made use of both by collectors in catching the moths and by the farmer and gardener in killing the “cutworm”’ itself. The larva, when full grown, averages in length about one and one-half inches, and is, as a rule, dull colored, with or without obscure markings (see colored plate). This full-grown larva burrows into the soil a short distance, and turns into a brownish or reddish-brown or mahogany-colored pupa (see Figs. 14 and 15, colored plate). These pupae may winter over, when formed late in summer, or give rise to moths in August and September, which lay their eggs at that time on various plants, or on the ground near their food-plants. The larvae which hatch in late summer or fall, winter over in some concealed situation, and are ready for business in the spring. While many birds prey upon cutworms—and although they are eaten by some other insects, and are the victims of parasitic forms, to say nothing of diseases bacterial or fungoid—nevertheless we INJURIOUS INSECTS OF I909Q AND IQIO. 3 have to take active means to combat them if we wish to save our crops. This division has found poisoned bait, made of bran mash sweetened with cheap sugar, or syrup, or molasses, and made decid- edly green with a liberal application of Paris green, to be a very good remedy in a garden. A tablespoonful of this should be put at frequent intervals among the plants subject to attack; not, how- ever, nearer than twelve inches to the plant; for, in case of rain, the Paris green might be washed against the roots, and would injure or kill the plant. The Paris green should be mixed with the bran when the latter is dry. Thorough cultivation is an aid. Pieces of shingle or board, placed at intervals over the garden, serve as traps under which the cutworms hide toward morning, and enable them to be found and killed. Frequently the depredator will be found in the morning, within an inch or so of the plant cut, buried an inch under the soil. Young plants, when not too numerous, like cabbage, cauliflower, etc., when first set out in a small garden, should be protected by paper or tin, or a barrier of some sort, which should extend into the ground an inch or so, and two or three inches above the surface. This can be removed when the plant becomes so tough as not to invite attacks from the cutworm. On large acreages, fall plowing and thorough cultivation is perhaps the most practical treatment. Cutworms, as we said above, are always bad the next year after sod, since they normally live in such situa- tions. Some farmers, in 1910, reseeded their grain fields with flax on account of the former being destroyed by cutworms. The family Noctuidae is an enormous one. Professor Lugger, my predecessor, left a list of two hundred and thirty-five different species of the group, captured partly at St. Anthony Park, and partly at Duluth. Of this list, something like forty-five species are typical cutworms. Therefore, farmers can hardly speak of ‘‘the cutworm.” LE Fig. 1. A Cut worm and its work. 4 INJURLOUS INSECTS OF 1909 AND I9Q10O. A WHEAT-HEAD ARMY WORM. (Heliophila diffusa, Walk.) An Enemy of Timothy. About the first of July of the present year the note of alarm in connection with this unusual visitor was first sounded by a telegram received from Detroit, Minn.—‘‘Worms damaging corn and grain badly here. Please send man to investigate.” July 5th came another one from MHeron Lake— “Green worms working on wheat, oats and rye. Send man to introduce method of extermination. Condition serious.’ Following these, and all in July, came complaints from Russell, Canby, Walnut Grove, St. James, Elbow Lake, Windom, Cottonwood, Revere, Marshall, Worthington, Hills, Tyler, Battle Lake, Ashby, Murdock, Stillwa- ter, Ruthton, Hendricks, and elsewhere. Men were of course dispatched, upon receipt of the above telegrams, to the places asking for help; and we were kept busy during midsummer in going from place to place and doing what we could to instruct farmers in the methods necessary to overcome the trouble. We found in every instance that the original sched 20 as tear ae aoe ead infestation came from old timothy fields Worm, A. diffusa, a, a, worms —fields that had been allowed to stand feeding on head of grain; b, : eggs under a leaf sheath; c,d, for from six or seven to ten years Below, fienals eats ates ewan Ome feeling the plow, and offering smin, ""esy °F 4T- B- ideal conditions for the increase of the pest. It is probable that this army worm was present and increas- ing in 1909, though its numbers at that time were not sufficient to attract the attention of the farmers. The drouth of 1910 was probably also in part responsible for the devastation of the current year. These army worms (see Figures 1 and 2 of colored plate) vary in color from green to a very dark brown, or even blackish, but almost invariably show characteristic stripes on sides and back. INJURIOUS INSECTS OF I909 AND IQIO. 5 They are a quite different species from the army worm which is familiar to the majority of Minnesota farmers. H. wunipuncta, and which is commonly known as “The Army Worm.” The Wheat-head Army Worm, the species under discussion as causing damage this year, is not a fre- quent visitor in Minnesota, or anywhere else for that matter; and it may be many years, barring its possible occurrence in small numbers in 1911, before we are troubled by it again. It is widely distributed over the United States, as far west as the Great Plains. When full grown, at which time the caterpillar is about one and a fourth inches long, they go into the ground two or possibly three inches, and turn into mahogany-colored pupae about three-fourths of an inch long, resembling closely Fig. 14 of the colored plate, from which the pale brownish or “clay yellow” moths (Fig. 3 of colored plate) emerge later. The female moth lays its eggs on the leaves (timothy, grasses, grains, etc.); which eggs hatch into the above-named worms. We found many of them enter- ing the pupal stage shortly after the middle of July; hence it would seem that it is two-brooded, or at least partially so in Minnesota; but it would appear that the second brood of worms, coming late, after harvest, might meet with difficulty in finding food. It is not out of the way to say that at least four- fifths of the timothy seed crop in central and southern Minnesota has been destroyed this year by this species of army worm, and the timothy materially injured as a hay crop. A conservative farmer near Marshall, esti- mated the loss on the hay alone as equaling one-fourth of the crop, or a loss of about $2 on every acre. In the vicinity of Otter Tail, it was roughly estimated that i they had nearly destroyed 200 acres. Around Battle Lake, about 1,000 acres were badly damaged. A farmer at Windom states that he lest $150 on his tim- othy crop. From Russell we received a report that from 1,200 to 1,500 acres of timothy was practically Fig. 3. Heaa destroyed. From another section, 95 acres of timothy vo. erred ty the ‘vas reported as a total loss. A statement received Xrmy worm from Heron Lake (July 13) was to the effect that the Original. SS 6 INJURIOUS INSECTS OF I90Q AND IQIO. seed of 75 per cent. of the timothy acreage had been destroyed. From St. James, same date: ‘Timothy is entirely destroyed, absolutely worthless for seed. Timothy crop has been damaged from 20 per cent to 25 per cent for hay. Timothy will cut inom three-fourths to one and one-fourth tons per acre.” From Tyler, “The timothy crop of seed in this sec- tion is practically allgone * * * and what hay we get is short and thin.” From Windom, July 15th, “Twenty acres (of timothy) are a total loss.” About July 7th, A. @. Sexe, near Elills; repented that this army worm had about completely de- stroyed his forty-acre field of timothy. Under date of August 27th, 1910, Northrup, King & Co., in a letter to the entomologist, in which they speak of the serious loss in sections where most of the timothy seed is harvested, state that timothy seed had nearly doubled in value. This, however, was in a large measure due to the drouth of last sum- mer. Conditions practically identical with those in Minnesota prevailed in parts of lowa and the Da- kotas. Mr. Urbahns was sent to Worthington, Minn., July rath. He found army worms had done much damage to timothy by feeding upon the heads. The injury was most severe on high sandy soil. The larvae were rapidly pupating on above date, and their work for the season was over. He met fifty farmers more or less interested 1n the control of this pest, and carried on discussions concerning com- bative measure. In every case investigated, as stated above, we found that the pest had its origin in old timothy fields that had been allowed to run a number of years, four or more, without being plowed. After the timothy heads are eaten, the worms turn their Fig. 4. Head of attention to oats, wheat or corn, traveling in an barley injured 5 by Wheat-head army from one field to another, hence their name. Army Worm. E : Ome int, They appear to be somewhat subject to the at- tacks of parasites; and are undoubtedly, in common with other caterpillars devoured by predaceous INJURIOUS INSECTS OF 1909 AND IQIO. 7 beetles, by birds, and die on account of fungous or bacterial diseases. Nevertheless, these factors simply serve to keep them within bounds, and it is absolutely necessary, when a farmer is confronted with a horde of these worms stripping his timothy field, and pre- paring to march to grain fields, to know what to do ,and to realize that whatever is to be done must be done without delay in order to be effective. Fall plowing and the rotation of crops, sovereign remedies for many field-insects, are valuable here. If farmers would plow up their timothy fields at least once in three years, it would be a help in connection with this or any other insect which found there an undisturbed breeding-ground. Another year, quite possibly, this army worm might not originate in timothy, but be found begin- ning its depredations on some other crop. Its repression, there- fore, appears to be dependent upon proper farm practice. In cases of serious infestation, as in the present instance, when a farmer’s crop is threatened by these worms, and the land is in a condition to allow it, he should plow one or two deep furrows across the line of march of the worms, the steep side of the furrows toward the crop to be protected. The worms collect in the furrows and can be killed with kerosene, or better, with crude oil. If post-holes eight or ten inches deep are made at intervals in these furrows, they form traps into which the worms fall. Or, the ditch or furrow may be partially filled with straw, which may be wet with kerosene and burned after the worms have collected thereon. A farmer can spray a broad strip about the worms, or across their line of march, with Paris green, at the rate of two or three pounds in roo gallons of water; or arsenate of lead (better than Paris green) at the rate of four or five pounds in 100 gallons of water. Sometimes it is practicable to drag a heavy roller over the advancing worms. Dust- ing Jry Paris green on vegetation about the worms may be re- sorted to. Fields where they are entering the soil to go through the resting stage should be plowed—harrowing is not sufficient. Co-operation in the attack is necessary; for there might remain on one man’s place enough worms to lay waste the entire neighbor- hood later on, if every one did not take preventive measures. The presence of this worm on cured hay does not poison it for stock, as some farmers have supposed. From July 11th to 13th, Mr. F. J. Crider of this division was in the field. His report in detail follows: CONDITIONS AT WORTHINGTON: I was taken out into the field around Worthington by Mr. Jones. Spent half a day in this way; talked to several farmers of the community in regard to the work of the army worm. Dam- 8 INJURIOUS INSECTS OF I909 AND IQIO. age from the insect was confined entirely to timothy; did not go into grain. The seed crop of timothy was a total loss. Most farmers cut the timothy for hay, but state that its hay-value was greatly lessened by the work of the insect—20 to 30 per cent was the average estimated loss on hay. The worm not only destroyed the head, but in many cases stripped the plants of their leaves. The greater amount of damage was reported from old timothy fields that have not been broken in from five to ten years. Some farmers did not use their hay for any purpose, but left it standing in the fields. It now presents the appearance of naked stems, destitute of heads or leaves. I searched, and found several live pupae just beneath the surface of the ground; but the majority of the insects seemed to have already changed to the adult stage, as was evidenced by the great number of empty pupal cases that were found. I counted as many as a half-dozen empty pupal cases in an area of sod six inches square, and among those only one live pupa. On the whole, however, there are yet a great many pupae still in the timothy sod. Mr. Jones is very much interested in the work of eradicating the army worm. He expressed a willingness to co-operate with the Station in any way possible. Says that he shall be glad, and wants to bring the farmers in closer touch with the Station, in a way that will benefit them. He will distribute literature, etc., among the farmers of the community, if such is desired. CONDITIONS AT WINDOM: Called on Mr. Brown, County Auditor; talked with several farmers of the community, and went out into the fields around Windom. About the same conditions were found as at \\orthington. From the standpoint of seed, the timothy crop is a total loss. Most farmers have cut the fields for hay, but state that its value was greatly lessened by the work of the worm. No damage was reported concerning grain-fields. The work of the insect was confined to timothy alone. Found some live pupae in the fields in timothy sod, and a great many pupal cases, showing the adult had already emerged. Mr. Brown was very pleasant, and wished to render the Station any assistance possible. CONDITIONS AT St. JAMES: Went out to Mr. Otto Uhlhorn’s place; walked through the fields all the way out. Mr. Uhlhorn and other farmers stated that the damage from the army worm was confined to timothy, except on the edges of grain-fields adjoining timothy. The timothy crop is a total loss for seed, and 25 to 30 per cent loss for hay. Most farmers used the crop for hay, a few fields were not cut at all; fields of old timothy sod were damaged worst. New timothy fields, near old sod, affected worse than entirely new fields or fields away from old sod. Insect appeared when timothy came into blossom, and remained until the crop was destroyed. Heard of one man at Darfur, seventeen miles from St. James, whose oats were attacked to some extent by the insect. Charley Stark, Mountain Lake, had a field of timothy for seed, that was entirely stripped by the 17th of July. Looked for pupae in the fields, and found the same conditions as at Worthington and Windom. Several live pupae were found, but mostly abandoned pupal cases. INJURIOUS INSECTS OF I90Q AND IQIO. 9 Mr. E. W. Stafford was sent to Heron Lake on July 6th, and makes the following report: Examined conditions at Heron Lake. Army worms have been working on timothy which is becoming mature and being cut. They now are migrat- ing to other crops, e. g., wheat, oats, barley, corn. These larvae have de- stroyed most of the timothy seed in the environs of Heron Lake. As timothy is ready to cut, maximum damage is already done to that crop. Rye is much of it cut, so not damaging it. One farmer’s oats so badly infested that he cut prematurely for hay. Recommended plowing furrows and use of kerosene and crude oil. Placed larvae on kerosene can almost dry; died in 45 to 60 seconds. Examined field of corn belonging to Mr. Pratt; across road, a badly infested timothy field, on farm of Mr. Smith. On farm of C. P. Fiske little infestation. In Pratt’s field the rows near timothy were badly infested with army worms. Attacked central shoots, ate holes in leaves, and ate on edges of the leaves. Degree of infestation decreased as one advanced away from edges of field. After about 35th row, little or no infestation. Looked at corn rather late in the evening, and found many larvae on the ground. It rained the day before examination was made, and Mr. Fiske said larvae on his oats were not as plentiful as the day before. Visited the farm of Mr. Geo. Reynault, and found army worms migrating from cut timothy to other crops. Attacked oats, wheat and barley equally badly. At edge of fields, found great numbers; ten feet in, found a few, and at thirty feet found none at all. It is said that some timothy fields have been left as long as ten years. Where there was no timothy there was no trouble with the worm. Much of the grain will soon be harvested, so will be out of danger. Many farmers are enthusiastic about the idea of using crude oil in the furrows. Price is lower, and it will not evaporate so readily nor penetrate into the soil. The worms do more damage to wheat than to other crops, as they often cut off stems at base first thing, then the whole head falls off. In oats, the larva consumes one kernel at a time. I did not find any on flax, clover, alfalfa, nor on the swale grasses. Went out with P. B. St. John to farm of John Maxner. Timothy being cut, corn adjacent. First forty rows rather bad. He had put Paris green on two rows, with little or poor results. I examined the stubble for larvae, but found none. Went to Shaeffer’s farm. He had cut a furrow about two feet from edge of field, and left strip as trap. This got covered with larvae, and with a pail he collected a large quantity, which he killed. The Wheat-head army worm. lO INJURIOUS INSECTS OF I90Q AND I9QIO. GRASSHOPPERS. During the summer of 1910 grasshoppers have worked more havoc than for years before. Numerous complaints were received in 1909, but it would seem that these complaints merely indicated that the “hoppers” were gathering their armies, as it were, and pre- paring to work all the havoc they could in 1910. The accompany- ing map indicates by crosses the counties from which complaints regarding grasshoppers were received during the above-mentioned two years, and also the number of localities in each county from which we received inquiries; by far the largest number representing complaints sent in during the season just passed. These crosses represent by no means the entire number of inquiries or reports of injury, since in almost every case many complaints came from one town. The circles shown mark localities suffering in I910 from the attacks of the Wheat-head Army Worm. Marshall 2 + ++ Clear Wat Racal g pesca) Sg § a | > 7 i+ i) oy a ies ° ze ex ost e Siri s + + ° . eet TIN 7 [septal Teal Ragefiite Eta ele TEG Sel seit oFee Rhone rca Sle eal eased eee ea Fig. 5. Map of Minnesota. Crosses show localities from which complaint was received of grasshopper injury. Circles denote localities reporting Army Worm injury. INJURIOUS INSECTS OF I909 AND IQIO. II With all due appreciation of the help given this division by the state press, perhaps no insect is used more than the grass- hopper, by ambitious young reporters, to make a good story with scare head-lines. What made it more aggravating in this instance was the continual confusing of the Seventeen-year Locust or “Har- vest Fly’”—which is a sucking insect and not a true locust or grass- hopper—and the grasshoppers or true locusts, which have been so unpleasantly prominent this year. To illustrate, we quote one or two absurd statements from county papers. The Tribune of Stew- art, Minn., under date of August 19, 1910, says: “But within the past week several farmers have seen the genuine red- legged, Seventeen-year, or Rocky Mountain locusts flying high in the air.” On January 19, Ig1o, the Standard, of Albert Lea, had some reference to a visitation of Seventeen-Year Locusts. The entomol- ogist, in a desire to straighten the matter out, sent a letter to the editor. Note how the editor treated it in his issue of February 2, IQIO: Figs. 6 and 7. Cicada or Harvest Fly, commonly called locust, and a true locust, commonly called “Grasshopper.” ‘‘No Fear of Grasshoppers.’’ “The Standard is in receipt of the following letter, which ought to dispose of all predictions and guesses concerning the pest mentioned.” i INJURIOUS INSECTS OF I9Q09 AND IQIO. “Hprror STANDARD: I note, that in your issue of January 19, you have a reference to the coming of the Seventeen Year Locust. No prediction re- garding this insect has gone out from this office at any time; and, as you say, quotations of this kind are frequently unfulfilled. It seems a pity that things of this sort are spread over the country, unnecessarily alarming citizens, and causing more or less of a reflection upon the entomologist.—F. tL. Washburn, State Entomologist.” There is no prospect at present of an invasion of the Periodical Cicada or Seventeen-year Locust, though many states to the south and southeast of us have periodical appearances of this in- sect, which passes the seventeen years (or thirteen years in the case of the 13-year form) of its larval life in the ground. It is not out of place, perhaps, to take this opportunity to advise farmers to avoid accepting unauthorized statements regarding insects, appear- ing in the daily or county papers, and to read most carefully any communication authoritatively signed; for sometimes, as in the above example, the heading and the information contained in the letter are quite at variance. One will note, upon looking at the accompanying map, that grasshoppers were pretty well distributed over the state in 1909 and 1910, drawing this conclusion from reports and complaints received through the mails, but that they became much more nu- merous, and consequently much more destructive, as one went west and northwest from St. Paul; and that in the Red River Val- ley, throughout its entire length, they were particularly severe. These are all native locusts or grasshoppers, as we all call them, as far as seen; and, when they are bad at all, loss is bound to be felt in the area indicated. In other words, in a farming locality which one might call a pioneer region, in that it is in the imme- diate vicinity of large tracts of untilled land, we will always have times of more or less trouble with grasshoppers. Although the yield of flax has been materially reduced, the entomologist does not believe that the entire output of grain by Minnesota has been materially diminished in 1910 by this year’s attack. But that is not the point at issue at present. The fact that INJURIOUS INSECTS OF I909Q AND IQIO. lle. many of our hard-working and deserving farmers in the counties indicated have lost materially, anywhere from a fifth of a crop to their entire crop production, and that some are so thoroughly discouraged as to think of abandoning farming in Minnesota, should interest state authorities sufficiently to cause them to inquire into the reason for these periodical invasions, and find a remedy. The reason is not hard to find. Large tracts of land which have reverted, or which have never been cultivated, held by speculators or others, offer ideal places for the egg-laying of this pest; and there are thousands of acres of such land in the western part of this state, where owners are absolutely indifferent to the fact that farmers, endeavoring to make a living on the out- skirts of these pest-breeding acres, have to make prodigious efforts to secure crops, and frequently fail altogether, because they cannot cope successfully with the hordes of grasshoppers pouring in upon them from the above-mentioned uncultivated acres. We have a grasshopper law in this state; but, inasmuch as the owner or lessee of such dangerous land is not obliged by this law to pay for the plowing, it is ineffective. We have the names and addresses of many of the owners or holders of such land. and a list of their property in Wilkin County; and have written some, only to find— knowing as they do, the weakness of the law—absolutely indiffer- ence, carried to such an extent in one or two cases that they did not even take the trouble to answer our letters. There are thou- sands of acres of such land in Wilkin County alone—the undis- turbed breeding-ground of millions of grasshoppers. In Andrea ~Township alone we have a record of over 8,000 acres of such land. Manifestly a county cannot stand the expense of plowing these tracts, even if sufficient men could be secured to properly do the work. Two ways are open, which would seem to offer at least partial relief for this deplorable situation; one, the work of the individual farmer, properly directed by experts, aimed at keeping the hop- pers off his growing crops, and to that end using intelligently not only well known methods, but others which may be discovered through investigations of entomologists; and second, the creating 14. INJURIOUS INSECTS OF I9Q09Q AND I9QIO. of a more stringent law—something like the grasshopper law of North Dakota, perhaps,—obliging large land-owners to bear the expense involved in fighting this insect. We are heartily in favor of such a law for this state. We want also to have, for the next two or three years, an expert in the field constantly, located at a central point in what we might call “the grasshopper district,” and not only trying various new methods available for the farmer, some of which we have in mind at present, but also going from place to place where needed by farmers, and instructing them how to properly apply the best known measures of protection. Such a man would be immensely useful to farmers in a stricken locality, beside being in a position, from a constant careful study of the sit- uation, to make valuable suggestions along new lines of control. Further, we have recommended to the Governor and the State Auditor the advisability of keeping upon the Auditor’s books a sum which does not revert, but is always available in times of crises, to meet emergencies along these lines. For a time there was such a fund, consisting of several thousand dollars, left over from early grasshopper days. This has reverted long since, and at present there is absolutely no fund to draw upon if we ever have a sudden and destructive visitation of grasshoppers. The writer has suggested that a fund of from $12,000 to $15,000 be kept upon the books, for emergency use only, and its expenditure properly safeguarded by a board or commission. This plan has met with the approvat of the State Auditor, who states that he sees no rea- son why such a bill would not receive the approval of the Legis- lature. In April of the present year (1910) a report was received, from a farmer living at Granite Falls, that the unusually warm weather in March had brought out the young grasshoppers, and that they had been killed by the freeze in April. This would have been good news if it had been actually the case in all arts of the state. Un- fortunately, grasshoppers were found hatching in large numbers early in May, when all danger of cold weather had passed; and our hopes, based on earlier reports, if we had such hopes, were doomed to disappointment; for, in the eight years and more we have served Minnesota, we have never had so much trouble and so much complaint as in 1910. Twenty or more afflicted farmers in Wilkin County were in correspondence with this division on ac- count of this trouble, and we have had men in the field assisting them, showing them how to construct and use hopperdozers. INJURIOUS INSECTS OF I90Q AND IQIO. I5 Plan of Hopperdozer. Urbahns. Fig. 8. North of Wilkin County, near Crookston, Fertile and Beltrami, and also in Otter Tail County and elsewhere, practically the same conditions existed. In some cases we fur- nished oil free to farmers, for use in hop- perdozers. There is no law directing the entomologist to do this, but he looked upon the existing conditions as an emergency, and wished to do all he could to assist men en- deavoring to raise crops under these trying conditions. Perhaps fifty hopperdozers were in daily use in one neighborhood in Wilkin County. Letters complaining of grasshoppers be- gan to reach our office early in June, rapidly increasing in numbers during that month, and continued arriving in large bunches un- til late in August and even into September ; and this division of the Experiment Station was kept busy, both in visiting different localities and in correspondence. We mentioned above the furnishing of free oil to needy farmers who required it for hopperdozers (see account below). In this connection it should be said that the State Entomologist’s fund is not sufficient to meet any such demand, and particularly would this be the case if we were deluged with the pest. It is to be hoped, therefore, that some special legislation may be en- acted this winter, covering the needs in question. 16 INJURIOUS INSECTS OF I90Q AND IQIO. KEROSENE ALLOWED FARMERS FOR COMBATING GRASSHOPPERS IN 1910. June 18 We We kowles, Biverdelilteecss eee 25 eealsisumoresD TUNer ls Vee he MIder HoxhOome eerie. Dp 2.94 June Zoe Ohassskveber, Hoxhomlemren see ce 50 s 6.25 Junee24 Hews SUGLELY HO xMOMEeH eerste crore 10 ie 125 June! 24 He J. Marsh) Hoxbomese emcee. cere 5 S .63 Aine, 7 PEAS) COMER, IopeIN@MNME> oo ooo cenoonesos 18 e 2.25 June 26 Henry Hendrickson, Everdell......... 25 ss 3.25 JuUNee Ziel) SLOnechant.s EOUNSayaeim erie ere 45 a 5.85 July AG Mes Gammes Beltramilerr siete 20 ot 3.00 July Cake Wukmianweb clita rier 25 ‘ Be July Bo.Os Lindberss beltiramibeee scene 20 es 3.00 July IM, We dbenyA Ballina. 500 cee cooudGGS + 20 x 3.00 July Ce) NordlumssBelitramit eer ee eeeeee ice 20 - 3.00 July 6 O. K. Bjerkebek, Breckenridge........ 10 - 1.50 July 8 O. K. Bjerkebek, Breckenridge........ 10 oY 1.50 Ambler 8) co maccandovonedc 15 SS 1295 Aug. 17 Benesh & Pierce, Breckenridge....... 50 i 7.00 Aug. 18 Benesh & Pierce, Breckenridge....... 50 a 7.00 vy * (gaDouTA INJURIOUS INSECTS OF 1909 AND IQIO. ly Fig. 9. Hopperdozer at work. Original. The grasshoppers causing the damage in 1910 have been, as far as we have seen, the Red-legged Locust or grasshopper, the Lesser Migratory Locust or grasshopper, the Two-striped Locust or grass- hopper; the latter being extremely numerous, compared with its Fig. 10. Hopperdozer at work, front view. Original. 18 INJURIOUS INSECTS OF 1909 AND IQIO. numbers in former years. Some farmers thought, because they saw swarms of locusts in the air, that they must have been the Rocky Mountain form; but we saw no evidence of this species, and will have to call attention to the fact that the Lesser Migratory Locust, as well as other forms, probably, have this habit in common with the Rocky Mountain variety. Further, farmers must bear in mind that any grasshoppers can be destructive in proportion to their abundance. They do not need to come from the Rocky Mountains in order to be dangerous. Friends of the writer, entomologists who work in Colorado and Montana, stated in 1909 and also in Ig1o, that for some time they had been unable to find, in their rep- resentative states a trace of the form known as The Rocky Moun- tain Locust, Caloptenus spretus; which species, by the way, is very closely allied to our common and destructive Lesser Migratory Locust. While in the field in Wilkin County, July 6th and 7th, 1910, we found the Two-striped Locust very abundant, for the most part full-grown and some mating. Of the Red-legged and Lesser Migratory there were more young than adults. At these dates also we occasionally saw quite large swarms high in the air, and coming apparently from the West. Observations. In addition to field work with the farms in r910, we have made some laboratory observations which may be of interest, and tried experimentally a solution (arsenite of soda) in successful use in South Africa. Fig. 11. Another view of working hopperdozer. Original. 1. We have found that young hoppers, freshly hatched, can live from four to five days without food under trying conditions— a fact which is not particularly encouraging to the farmers. INJURIOUS INSECTS OF I909 AND IQIO. 19 2. Avery young hopper will average, in traveling on hard soil, about one foot every five minutes. They make about one foot at a jump, rest awhile and jump again. On soft soil their rate of travel is very much less than on hard—only a very few inches every five minutes. Fig. 12. Scooping out the dead hoppers. Original. 3. The accompanying drawings, made from living specimens by Miss Iris Wood, show the successive stages in the hatching of a grasshopper, and its freeing itself from the enveloping membrane, or so-called “amnion.” Fig. 1, breaking through the egg-shell; Fig. 2, a few minutes later; Fig. 3, still later; Fig. 4, freed from the egg-shell, but still wrapped in the “‘amnion’’; Fig. 5, kicking off the “amnion.” The length of time required in this process varied from about four minutes to fifteen, possibly dependent upon the amount of moisture present in the soil containing the eggs. 20 INJURIOUS INSECTS OF I909Q AND IQIO. Quoting from Miss Wood’s notes, figure 3 was drawn at a time when ‘‘a strong movement was observed between thorax and ab- domen.” Almost no independent movement of legs until the pellicle or “amnion” is cast off. This (casting off of the amnion) began to take place immediately when the hopper was free of the egg-shell (Fig. 4). The pellicle split across the back of the thorax, and, by movements more of the body than the appendages, was passed for- ward over the head. The antennae and mouth parts were drawn out of the pellicle; then the first and second pair of legs were drawn out, and in about three minutes the entire amnion (pellicle) was cast off, but clung several minutes to the posterior end of the ab- domen. As soon as the hind legs were free, the hopper turned over and began to walk, at first using only the two front pairs of legs, the tibiae and femora of the hind legs being close together and raised, and the body dragged along by the front pair.” 3 4 & Five stages in the hatching of a grasshopper. Original. Remedies and Preventive Measures. (1) THE PLow AND THE Harrow are the most important ene- mies of grasshoppers. A faithful use of the plow on the part of all farmers 1n a neighborhood, and all land-owners, will materially re- duce the number of this pest in any given locality. As is well known, grasshoppers lay their eggs in late summer and early fall, in pockets made by the female, an inch or an inch and a half deep. These INJURIOUS INSECTS OF I90Q AND IQIO. 21 eggs hatch in the spring, in normal years between May rst and May 15th, or thereabouts. These pockets are turned over by the plow, preventing the escape of most of the newly-hatched hoppers. Con- sequently late fall or early spring plowing (five or six inches deep) is one of our best remedies against these insects. Evidently, there must be co-operation on the part of all farmers in a neighborhood, in this important matter. Where deep plowing is impossible, a faithful harrowing would help shallow plowing, thus more effec- tively breaking up the egg-masses and exposing the eggs to the varying changes of the weather. The plowing of roadsides in the late fall or early spring, where there is serious infestation, is de- sirable. (2) PLow1nc UNDER YounG Hoppers: Young hoppers just hatching can sometimes be taken care of by plowing them under, beginning on the outside of the field in which they are hatching, and plowing toward the center. This turns many under, and by depriving them of almost all food, makes it much more difficult for them to reach the edge of the plowed piece where they might dam- age a valuable crop. (3) CrippLtE Mixture: When grasshoppers are young, or half grown, a poisonous bait, known as the Criddle Mixture, has proved effective in many parts of the country. This consists of one part Paris green and about 100 parts of fresh horse-manure, by measure. Enough water is added to make the mass soft without being sloppy. It can be taken to the field on a wagon or stone- boat, and scattered about by means of a paddle. One might think that turkeys and other fowls, in picking over such material for bits of undigested grain, might be poisoned. This, in our own expe- rience, does not seem to be the case. It would probably be dan- gerous if used in proximity to small chickens. (4) Burninc Younc Hoppers: It is sometimes possible to burn over a tract swarming with young hoppers, and thereby save an adjoining crop. This burning, however, must be done with care, and the farmer must decide whether he is doing more harm to his hay crop than he is getting benefit thereby. (5) Potsonep Bran: Garden truck to which chickens do not have access may be protected to some extent by mixing bran with water to the consistency of chicken feed, adding Paris green until the mixture has a greenish color (2 parts Paris green to 25 parts bran, by measure), sweetening with cheap syrup or molasses, and 22 INJURIOUS INSECTS OF I909 AND IQIO. strewing the same amongst the plants, taking care not to place it directly against a plant. Spraying garden vegetables and other plants with arsenate of lead, 4 pounds to too gallons of water, would also serve to protect them. (6) Hoprprerpozers: These, though not giving complete sat- isfaction, are regarded as one of the best helps; in fact, almost the only help, for a farmer upon whose crops the grasshoppers are pour- ing from adjacent unplowed fields. Hopperdozers are made of sheet iron, generally 16 feet long (though they may be shorter), and the drawing which accompanies this article illustrates a general Fig. 14. Experimenting on small scale with arsenite of soda. Original. plan. The upright part behind may be canvas or cloth, or of sheet iron. With the details suggested by Fig. 8 farmers should be able to construct one to suit their needs, and possibly improve upon the plans given. I might say, in this connection, that a horse at each end is better than one horse in the middle. When wanted for use, a little water is placed in the pan and also thrown against the canvas-cover back, if canvas is used. This back is then drenched with kerosene, and about two quarts of the oi! are poured on the water in the pan. The machine is driven back and forth over fields of young grain or flax which is being eaten, and bushels of the insects are killed in this way. This work is’ best done when the day is bright and warm, and before the insects reach full size. Even though a grasshopper may jump out of the pan.—if he has been in the kerosene, he is doomed. INJURIOUS INSECTS OF IQOQ AND IQIO. 23 (7) PLowine a Strip TO CHECK ADVANCES OF YOUNG Hop- PERS: In case a farmer is located next to an immense tract of unplowed land, whereon grasshoppers are hatching in large num- bers and threatening to overrun his crops, manifestly he cannot do the impossible—in other words, plow all the reverted or unused land ;—but he might plow a strip of this infested land several rods wide, along the side of his own land, thereby forming a barrier which it would be difficult for the very young hopper to cross, and thus giving time to prepare other means, (hopperdozers, for in- stance) to use against them. (8) THe MInNNEsoTA GRASSHOPPER Law: This is strikingly ineffective, as stated above, and we would do well to follow the example of North Dakota in this respect. The method of pro- cedure under the Minnesota law is as follows: Complaint of the infested land should be made in the fall, to the State Entomologist, or to the Board of County Commissioners, or both, accompanied by specimens of eggs. The entomologist ex- amines the land; and, if conditions justify it, he recommends to the Board of County Commissioners that the lana be plowed. The County Board serves notice on the owner cr lessee of infested land, requesting him to plow within a certain time. If he fails to do this, the county plows the land; and, if said plowing benefits him in rais- ing crops immediately after, assesses him to refund the money paid. It is evident that, under the provisions of this law, the county will have to pay most of the bills for plowing. If our farmers think this law should be made more stringent, and the owner of said prop- erty be made to pay for the plowing in any event, it is in their power to make an effort to amend the present law to that end. The North Dakota law, given below, is more stringent in that the expense of plowing is made a lien upon the land, and the record Owner or incumbrancer of said land must pay the cost of plowing. Revised Code of North Dakota, 1905. ARTICLE 27.—DESTRUCTION OF GRASSHOPPERS. Sec. 2108. Duty of County Commissioners.—The Board of County Com- missioners shall have power, and it shall be their duty, to order the plowing of land, and such other means as they deem expedient, wherever and when- ever they deem it necessary to cause the destruction of grasshoppers and Rocky Mountain locust’s eggs: and said plowing and other means shall be done at the time and in the manner directed by said Board of County Com- missioners by the owner or incumbrancer, if any, of said land immediately after receiving notice thereof from said ‘Board of County Commissioners. 24 INJURIOUS INSECTS OF I90Q AND IQIO. Sec. 2109. Notice, how and when served.cWhere the owner of the land on which said Board shall have decided plowing must be done for the purposes herein specified, cannot with reasonable diligence be served with notice within the state, it shall be sufficient to serve the said notice by publication thereof for two successive issues in the official newspaper nearest said tract. Sec. 2110. Must plow in five days.—If the owner or incumbrancer, if any, shall fail to plow said tract or tracts as ordered and directed by said Board of County Commissioners, within five days after notice as herein pro- vided, then, in that event, said Board of County Commissioners shall cause said tract or tracts to be plowed, or so much thereof as may be by them deemed necessary, and audit and pay for said work out of the general fund of said County, upon warrant as in other cases made and provided. See. 2111. Expense a lien upon land.—Immediately after the said ac- counts are audited and paid by said County Commissioners, it shall be the duty of the County Auditor to certify to the County Treasurer the amount so expended upon each piece and parcel of land, which certificate shall contain the name of the record owner or incumbrancer of said tract, a true descrip- tion of said land, the amount paid by the county for plowing done thereon; and the County Treasurer shall thereupon enter said amount against said land as taxes are entered against said land, and the said amount shall con- stitute a lien upon said land prior to all other incumbrances, and shall bear interest at the rate of seven per cent per annum from date of entry by the County Treasurer, and collection thereof may thereafter be made and enforced in the same manner as delinquent taxes are enforced and collected against real property. Sec. 2112. Payment out of general fund.—When the Board of County Commissioners shall deem the plowing of state land necessary for the pur- poses herein specified, they shall order the same done, and payment therefor may be made out of the general fund of the county, upon warrant as in other cases provided; provided, however, that no growing crops shall be de- stroyed under the provisions of this article; provided, further, that when the Board of County Commissioners shall deem it necessary to cause plowing upon government land held by resident claimants, or other means to cause the destruction of grasshoppers and Rocky Mountain locusts, said claimant shall be liable to the county in a civil action for all moneys necessarily ex- pended in carrying out the directions of the Board of County Commissioners for the purpose herein specified. A Partial List of Reverted Lands in Wilkin County in 1910. Of all localities this county appeared to be the worst affected during 1910, and since we have found that similar conditions in other counties in the Red River Valley are largely responsible for grasshopper injury, we give here a partial list of these lands in Wilkin, with the names of the owners or representatives of the owners, as reported to us at the County Auditor’s office: INJURIOUS INSECTS OF IQ0Q AND IQIO. 25 ANDREA TOWNSHIP. eV eh Gs SIMIO Aah clonsnctets, «) «ae coe! Mary A. Kenefic, care G. I, Byget, Day- ton, Ia. RISA VLaieree Ne) icing eects, citae, laid s ws O. Bertleson et al, Fergus Falls. ALBUS BOING allies AO, Sy Sera gy Sit. ohn eepaees J. R. Milliken, N. W. Nat’l Bk., Sioux City, Ia. See CUA oat nena ae Pons o Shaleles Camelia Allen. ERIN Pa oo ahaito reat evehe ayeaare, 8 4) M. R. Keeley, Dwight, III. U0) UND 2A Sees op Oe A oS ge P. G. Shaw, Pocahontas, Ia. SLES aM SAV ited. otere es ance Wen erawabclere midee vss A. W. and Willie Anderson, Stanhope, Iowa. MOMEINGW VAs ba sheckaksi ott oreo atte oe fe Paul Rinnengen, Big Bend Land Co., Spokane, Wash. PU SININV Higa hte Seay ie ® aecbens areal cid see etic Howard Espeset, Estherville, Ia. Zhe NN DL) ered oe tease 5 REL SICH NRE Jacob Niebles, Fergus Falls. Pe HIN het anle Wome Mabaso hers Sudlsele) Se F. F. Schnetstay, Fergus Falls. PRE SAVdeb a er cy cxere eh vaitene Kee heel alunos H. G. Richter, Foxhome, Minn. Toy SLD Nee ROCHE ARERR SRS Ch CRORE KH. and L. Edwards, Alta, Ia. Pe NIL VV Ris itatiats i oisccs anata hy ey cuctentitels. ate ee G. W. Johnson, Schaller, Ia. OMSL aerate. aire aetrnte. eA Re ets hersusshialls: MNS Hig Moments che he Jarces eRe anes es S. A. Rouse, Mankato. ere AUME Net aU RANT cid sae salah shel ors James Espeset, Estherville, Ia. Pre Oty ose ee AGNES eo Se «aya tae eyeye tiers A. R. Kitts, Fergus Falls. OMEN Gems atoSe., Ms antl aere cata ah ore W. L. Austin, Rutland, Ill. LON V ME AM rae te cit Lae? ocho sletace whobore ..-.- FH. EF. Frost, Des Moines, Ia. PLO Mi Ge? ehayans Aer. Fe. thet Ree aneteonte C. F. Livermore, Fairmont, Minn. AKRON TOWNSHIP. Ad IN Eri Ole NW ater ae ert a shel eee Sec. 20, Jonas Swenson, Fergus Falls. Dee AN Loe? O fet INI Wi liteaeecheutiay oct bw earenee ans Sec. 20, Jonas Swenson, Fergus Falls. Ie AN IS a ates ack She Sete hea bcs a ee tee te Caspar Lien, Fergus Falls. Pep I /ge Ole INIWiaesed euciatcdoeka en ce A. Swenson, Rothsay. Ad, No and SW of SWiesee sees. A. Swenson, Rothsay. EY) OL SIVA arch dptortaieaneteh ee Frank Gronnos, Elizabeth. PINS Av A: lah od revaycings: Sy ay Oe ete et te oes Andrew Christofferson, Rothsay. OR Hin 2 hee tetetlons, chateias eeaeennwat crane sae O. G. Felland, Rothsay. OO MAININV ia 2 cost tecuauohs terete ans arenets tang ote H. G. Heikland, Spencer, Ia. ENE OV VGO/A.” cae Avra avate lene quarantine eeiave Mortage M. J. Adams, Ames, Ia. OS Wa Sate Soa arene ees dee ens ehene H. J. Olson, Rothsay. Sor Ol> NIN laws wns eters E. E. Secor, care Harvey Johnson, Banning, Calif. Soros OL BIN Bit /4 a cucaeeree eee oiene otens H. L. Shirley, Breckenridge. Sea EE aires eobaver se oh heLere ae oa eee H. L. Shirley, ‘Breckenridge. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. Sec. INJURIOUS INSECTS OF I90Q9 AND IQIO. TANBURG TOWNSHIP. ED AN V io ewan otsiale syretvsneyie aid lo cl arioneteyedenetrs H. K. Farries, Morning Sun, Ia. DOMME GTOLOS Wi/gisisiesc cere sic eere ere J, E. Vincent, Britt, Ia. SO MHS OL INIWofiaescs 3 Se cee CPs Baileys BOS MWe ewOL INEZ cays tae B. F. Parker, St. Paul. SOT ANI Gee tio State helt eae 6 O. E. Jonsrud, Rothsay. DD eo ga anes aah cna eon e teceeeontis ceayi eres O. A. Smekop, Rothsay. MEADOWS TOWNSHIP. 2A MSIE Yaiake cles) © eres tek eve eee Walter Davis, care F. E. Boone, Breck- enridge. DAS IVS cimaiesticiesat vn betaie tele iegstels eee here J. A. Wigdahl, Rothsay. 1 ING OLA Score cn een rola clioaceaieactcee aie G W. R, Appleton. AMON WEL Gee ce, Seka take eee ee cree one O. P. Burrows, Breckenridge. TA SIV Uae torah ater cshecote te dere nee meee TS F. C. Felts, Fort Dodge, Ia. SEA SGU) Ae gs aiee dar ance, Cachialct ofan tenes arate F. C. Felts, Fort Dodge, Ia. LINDE OE IN Waa cite eo miseries eee P. L. Christianson. TINS COLUNIR Ai ae va a aices ete P. L. Christianson. 1ST VOf NN aim caine eee ae C. S. Marden, Barnesville, Minn. TS 26 SO NW aoe acc ee ere C. S. Marden, Barnesville, Minn. SLR, STW eke ec ssay Sache sana nee iorarie oheeeteats C. S. Marden, Barnesville, Minn. ING SIIHA obceo noe deoonddasaodo ss J. F. Buggy, Buffalo Centre, Ia. UO EBLE Witine scetueearsnevegsiae a aetrat eee ens ieee G. E, Ward, care J. C. Kain, Brecken- ridge. SRS IW siete a Sen eh cre oe R. F. Locke, Rockford, Ill. Seats Of tcrtoRS mecca > ctsteto io eens Cl oRateG Oscar Anderson. Dil one nate td cia vcieianeder cuekercesietere vers Otto Berg. ZONA Seer een Cae ee ae Naor ey ee S. I. Dakin, Breckenridge. ZO PAW Aoi eis ery he Coie oes E. J. Elliot, care E. G. Everett, Des Moines, Ia. SOFAS Hat ee eencnan, oictetemrcneoen anon F. T. Berkey, Breckenridge. EIN GWA sacs, steed corer eee eae tee G. W. Barrows, Breckenridge. DEIN i canter ve ee David Meridith, care J. A. Carlton, Dubuque, Ia. Nec Oe cS te i eaee H. K. Bjargaard, Rothsay, Minn. INJURIOUS INSECTS OF I909Q AND IQIO. to NI Testimony as to Conditions. The following letter, taken from a large number of similar com- munications, received in 1910, is fairly indicative of conditions in the Western and Northwestern part of our state. “Everdell, Minn., June 25, 1910 Mr. F. L. Washburn, State Entomologist, St. Anthony Park, St. Paul, Minn. Dear Sir: Received your order dated June 18th, for 25 gallons of kero- sene, and wish to thank you for the same. At the same time I want to call your attention to the fact that the farms I am working have a total of about twelve hundred acres in crop this year, and very likely there will be con- siderable more needed than the 25 gallons, Will you not furnish more? The grasshoppers seem to be very numerous, and already it is claimed that they have done and are doing damage. A number of farmers are trying to work against them with the hopperdozers, but the trouble is that there is so much land not being cultivated, growing grass; and it seems that they are very numerous on such land, and the trouble is that they breed on such Jand and afterwards go to the grain on the cultivated land. The situation here is fierce. ‘This will be the third successive year that the grasshoppers have been doing damage on a large scale, and if there is anything that you can do through the state to help the farmers in this locality, it ought to be done. Thanking you in advance for a prompt reply, I am, Respectfully yours,” These Grasshoppers Are Not the Rocky Mountain Locust or Grasshopper. Reference has been made above to the fact that the grasshop- pers doing the damage in 1909 and 1910 are not the Rocky Moun- tain variety; and it was further stated that for some reason the lat- ter form (M. spretus) has not been apparent in its usual haunts for many years. In this connection I quote from two letters recently received. One from the State Entomologist of Montana reads as follows : “T have been collecting Orthoptera in Montana for thirteen seasons now, and have in the collections about 170 species, of which about a dozen are new and undescribed. I have looked particularly for M. spretus (Rocky Mountain Locust), but have not taken a single specimen, nor have I taken one that approached this species. This has been particularly interesting to me, in 28 INJURIOUS INSECTS OF I9Q0Q AND IQIO. view of the fact that parts of Montana were formerly considered to be within the so-called permanent breeding grounds. I have collected within this tract as well as outside of it.” The other is from a prominent Colorado entomologist : “* * * Tn all of our collecting here during the past twenty years, and it has been quite extensive, we have never taken an example of the Rocky Mountain Locust, M. spretus. It is quite a disappointment to me, as I sup- posed I should certainly have an opportunity to collect this insect many times in Colorado, as Riley had given the permanent breeding-grounds of this insect as extending over a considerable portion of the mountains and foot- hills and even the plains in this state.” The Lesser Migratory Locust, WM. atlanis,—one we have with us all the time, capable, as we have seen, of doing great injury when occurring in large numbers, and with somewhat the same habits as the Rocky Mountain form,—is so closely akin to the latter that some entomologists regard them as almost identical, the latter possibly a long-winged variety of the former. The casual observer, not- ing them in the field, certainly could not distinguish the one from the other. Mr. Urbahns was sent into the field twice during the summer. His report follows: First trip made to Foxhome, Minn., June 38rd: Drove out to farms of Chas. Reber, O. L. Fuder, Geo. Sutter and G. W. Greiner. The young hoppers, just hatching, were very abundant, especially so on high sandy waste lands. Burning of meadows and idle lands was practiced wherever possible. In some cases this was done too early to destroy a large percentage of the young hoppers, and in other cases meadows were burned so late as to destroy the Zrass crop. A movement was organized to clear the fields of grasshoppers by the use of hopperdozers, through the joint efforts of the farmers of the entire locality. Mr. Chas. Reber was appointed chief in the movement. Promises for the construction and immediate use of eight hopperdozers were secured. Second trip to Foxhome, in June: Arrangements were made over tele- phone by which several farmers from south of town were met at the hotel. Two groups of farmers were met in the country at five and eight miles northwest of town. Fields were visited where hopperdozers were in use. The discussions carried on led to several changes in the construction of hopperdozers. Grasshoppers were apparently on the increase, but reports of the work were quite favorable and encouraging. A good number of hopper- dozers were in use, and farmers were urged to make greater use of the same. Rothsay, Minn.: Met four farmers at the home of Ed. Steiner, eight miles southwest, and then drove two miles north to meet eight farmers, who INJURIOUS INSECTS OF 1909 AND IQIO. 29 had gathered at a cross-road to discuss the grasshopper situation. Upon driving one mile farther north, to the home of M. F. Fisher, a meeting wag held in the yard, with six farmers present. These meetings were all hur riedly arranged by telephone, through the help of farmers interested in com: batiug insect pests. Farmers were reporting much idle land as a public nuisance, and nearly ten thousand acres were listed. Over eight thousand acres of such land were listed in a single township. Gentilly, Minn., June: Drove out eight miles to Gentilly from Crookston, and met a group of farmers by appointment. Twelve men interested in com: bating grasshoppers were present. A few others took slight interest. Re- ports of abundance of grasshoppers came in from all sides of town, and mostly from fields which were high and sandy. The situation was discussed, and the most practical methods of control were considered. Grasshoppers in this section were further advanced than they were around Foxhome or Rothsay. Farmers were enthusiastic, and seemed willing to at once take up the work as outlined. Beltrami, Minn.: I was called to this place by Mr. Johansen. The grass- hoppers had destroyed the barley in spots on a field of Mr. C, K. Luhman. A few crude hopperdozers were in use. A gathering of farmers was held on Mr Luhman’s farm, and the work was discussed. Young flax-fields were suffering severely, and the flax was too small to allow of the practical use of hopperdozers. Grasshoppers were mostly about half-grown. A second meeting was held in the evening, at the home of Ole Olson, with seven farmers present, for the purpose of discussing the construction of a most efficient hopperdozer. INJURIOUS INSECTS OF I9Q0Q AND IQIO. WORK OF 1909 WITH THE APPLE LEAF HOPPER. Empoasca malt. This practically marks the completion of work upon this insect, done under the provisions of the Adams’ Act, though some points of interest in its life-history yet remain, inviting further endeavor. The work of 1908 on this species was described in the Twelfth Report of the Minnesota State Entomologist. Summarizing that work we cite the following observations: us 2. 3. Fall-laid eggs were not found on any herbaceous plant. The insect winters only in the egg stage. Oviposition in summer was found to occur on the petiole of apple and clover, and probably occurs on other herbaceous plants. List of food-plants was given. Five nymphal stages were reported, covering a period of about twenty-two days. Adults may live fourteen days or over (1907 experiments indi- cate that they may live thirty days or more). The location and appearance of the winter egg-blister and the contained egg. Remedial measures. The work of 1909 practically corrobcrates that of 1908, and adds certain new facts. We add these conclusions and the chief items of work: 9. 10. ae 12. 13. This species deposits its winter eggs only on perennials, and of perennials, as far as can be determined, only on the apple. There are certainly three, and probably four broods in Minne- sota. Manner of emergence of nymphs from egg-blister. Further observations on life-history. Remedial measures. The work in 1909, as in 1908, was in charge of Dr. H. J. Franklin, and his report in detail is as follows: INJURIOUS INSECTS OF I9Q09 AND IQIO. 31 Empoasca mali. Alfalfa and dahlia plants, which had been badly infested with Empoasca mali during the summer and fall of t908, were brought in and placed in the insectary, and kept in the cold part of the greenhouse through the winter. These plants showed the effect of the insect’s attack plainly when brought in, and there were many of the insects still on them at that time—October 8th. No speci- mens of Empoasca mali lived through the winter on these plants, and no nymphs emerged from the tissues the next spring (spring 1909). This goes to show that E. mali does not deposit winter eggs in the tissues of herbaceous plants, and that the species relies entirely upon the eggs deposited in the blisters found on the bark of peren- nials. These plants were last examined in the season of 1909 on June 5th, and the plants were at this time more or less dead and dry, except for the new growth which had started up during the month of May, 1900. Fig. 15. Emergence of nyniphs from egg blister. Original. Apple branches were examined in the orchard early in the spring and were brought in from time to time, and the egg blisters of E. mali carefully examined, to find out when the nymphs should begin emerging from the blisters. Nymphs were found in process of emerging on May 24th, the apple leaves at this date being not over one-third developed. Numerous hoppers were found at this date in first and second instars on the apple leaves, and it seemed probable that some of them hatched from the eggs as early as May 2ist. Several adults were reared from nymphs hatched from these blisters, and, with one exception, they all proved to be E. mali. One undetermined specimen, which was slightly smaller than E. mali, was reared from a nymph which emerged from an egg- 32 INJURIOUS INSECTS OF I909 AND I9QIO. blister found on apple, which could not be distinguished in any way from the true egg-blister of E. mali. On May 26th Miss Wood made several drawings to illustrate the method of emergence of the FE. mali nymphs from their egg-blisters. These nymphs emerged through the oviposition opening of the blister, making this opening somewhat larger during the process. When a young hop- per begins to emerge from its egg-blister, if the weather is fairly warn, it will often complete the process in a few minutes. One was timed from the moment the vertex of its head appeared until it got clear out of the blister, and it took five minutes. Another was watched from the time it was half-way out until it got entirely free from the blister, and it took about thirteen minutes. The young hoppers were observed to be still emerging from their egg-blisters, in large numbers, on May 26th. The flower-buds of the apple trees were at this time, as a rule, just on the point of bursting into bloom, many of them being already in bloom, and the leaves were from one-third to two-thirds developed. From these observations there is now no doubt that the egg-blisters, which were so carefully measured by Franklin last fall, on the branches of the trees in the orchard, were those of E. mali. Evidence that E. mali does not hibernate in the egg stage on other perennials than the apple. Young leaf-hoppers were gathered from the foliage of elm, white oak, red oak, gooseberry, black birch, linden and white birch, from June 4th to June roth (at which time the nymphs of the first brood of E. mali were developing to the adult condition in the apple orchard) and reared to adults, to see if any E. mali had hatched from the winter egg in any numbers on these trees. Adults were reared from nymphs found on all these food-plants, but not one of them proved to be &. mali. Currant bushes, box elders, mountain ash, dogwood and some other perennials of less importance were carefully examined for young leaf-hoppers from time to time during the first two weeks in June, and not a single nymph or adult of any species was found. Willows were examined carefully on June 11th, and only a single young leaf-hopper was found. This was reared, and proved to be EF. mali. Plum trees were also examined carefully on June 7th, and only two nymphs of leaf- hoppers were found. One of these was reared, and proved to be E. mali. These observations clearly indicate that E. mali seldom, if ever, form winter egg-blisters on any of the kinds of trees examined, namely, elm, white oak, red oak, gooseberry, black birch, INJURIOUS INSECTS OF I909 AND IQIO. 33 white birch, linden, currant, box elder, mountain ash, willow, dog- wood and plum. Even in the case of the two last we have no certain proof that the specimens of E. mali reared from them did not first hatch from eggs in blisters on apple trees, and then get blown from the apple to the plum and willow trees, which were about fifty yards distant, though the chances for this, considering the observations made by sweeping on alfalfa, do not seem great. Notes and Observations on Life-History. On June 4th trees of the orchard on the flat were examined for this species; no adults were found on the apple trees, though nymphs were present in all stages. The alfalfa field just across the road was examined, to the north of this orchard, and swept with a fine collecting-net, and adults of EF. mali were found. No nymphs in any stage were found upon the alfalfa at this time, which again shows that this species does not pass the winter in the egg stage on or in alfalfa. The adults found on the alfalfa at this time had evidently come to maturity on the apple trees in the neighboring orchard, and then either flown or been blown by the wind from these trees on to the alfalfa. Counts were made of the number of specimens of adults that were taken by sweeping across the alfalfa field at various distances from the orchard. The field was 164 paces long, extending directly away from the orchard, and the width being about the same (52 paces) from end to end. For each count the width of the field was swept, taking one good sweep of the net at every step. The following table gives the number of sweepings, their distance from the orchard, and the number of Empoasca captured. Paces from Orchard Number of specimens taken Sweepings. 9 5 Once across. 130 1 Once across. 13 5 Once across. 21 3 Once across. 40 6 Once across. 60 8 Once across. 80 3 Once across. 100 4 Twice across. 120 3 Once across. 140 2 Once across. 164 eo Twice across. 34 INJURIOUS INSECTS OF I909 AND I9QIO. Making a total of thirteen sweepings across the field, and of 43 adults collected in all. | It will be noticed by this table that there was a slight falling off in the number of specimens toward the further end of the field; but that, aside from this, the Empoasca adults were pretty evenly distributed over the entire field. This field of alfalfa was swept several times after this, in a similar manner, with the results given below. On June oth: Paces from orchard. Specimens of adults taken. 10 14 20 fi 40 10 60 13 80 i 100 2 140 15 120 ial 160 12 Making a total of nine sweepings in all, and 91 specimens taken. No nymphs at all were found in any of these sweepings. It will be again noted that quite as many specimens were taken at a distance from the orchard as close to it. On June 11th the field was swept again with following results: Paces from the orchard. Number of individuals found. 10 37 20 22 40 19 60 i, 80 14 100 12 120 21 140 18 160 13 164 24 Making a total of ten sweepings and 192 specimens. On June 14th the results of the sweepings were as follows: No. of paces from orchard. No. of specimens taken. 10 iy) 20 23 40 22 60 14 INJURIOUS INSECTS OF 1909 AND IQIO. 35 80 14 100 it 120 Seat les 140 14 160 15 165 36 Making a total of ten sweepings and 177 specimens taken. On June 21st results of the sweepings were as follows: No. of paces from orchard. No. of specimens captured. 9 24 adults. 1 young. 13 30 es 20 3 40 28 x 60 18 S 80 28 Wy 100 24 i 120 20 140 22 ss 160 23 3 165 21 * Making a total of eleven sweepings and 268 specimens. It should be noted that this is the date on which the first nymph was found in the alfalfa. It was very small, being in the first stage. As the field of alfalfa on which we had made the previous sweeping had been cut down, we had to sweep another somewhat smaller field. The sweeping and counting on this field was done in the same way as in the other field, and the results were as follows, the field being about the same width as the one above, June 25th: birst sweeping -across. the field... ....<..% ses. «s- 55 specimens. SCONCES WCE DIMA ater eihs orailo cue ieseus ye ete sbale Sieg ofe eo eusae ie ns 60 $ PRIEMG eens WiC PINS cake she Sein 7 Cameume etic ten enc cc slcre eis eh ol 66 MOUGiES WiC PINS. © case tinh ae ol deh isteohae oie oe ees 40 ORES WCE DIME Mee that sbaunete kom eksiny ocicet sakes e.% sont V2 54 cy Making a total of five sweepings and 275 specimens. This field was somewhat farther away from any apple trees than was the first one. A few nymphs in the first stage were found. If the results of the sweepings made on these different dates be examined and compared carefully, it will be seen that the individuals taken increased steadily in numbers from the first to the last, with the exception that the sweeping on the 14th of June gave a somewhat smaller number of adults than did that on the 11th. This falling off on the 14th of June, however, is readily accounted for by the 36 INJURIOUS INSECTS OF 1909 AND IQIO. fact that on the 12th, and again on the 13th, there was a consid- erable amount of rainfall—over half an inch of water falling on the 3th—it being very probable that so much precipitation would kill off the adults in considerable numbers. On July oth the alfalfa field which was cut on June 24th was swept, and a number of specimens of FE. mali were found; the alfalfa since it was cut having attained a considerable new growth. Sweepings had been made upon clover at about this date (July oth), and nymphs were found in large numbers. Nearly as many adults were found upon the alfalfa on this date as were found on the clover, in proportion to the number of sweeps of the net. No nymphs, however, were found. The adults had apparently but recently either flown or been blown on to the alfalfa, from the neighboring orchard and from surrounding fields. The absence of nymphs on this field, which had been cut, goes to show that if legumes such as clover and alfalfa be cut just before the eggs for the second brood hatch, much of the infestation for the second brood may be reduced. On July 24th fields of wheat, rye, oats, barley and flax were examined and hardly any E. mali were found in them. On August 24th a large patch of raspberries, at Mr. J. F. Larson’s place at Stillwater, was looked over and many of the leaves on the rasp- berry canes were found to be badly curled as the result of the work of EF. mah. Many canes had all the leaves curled up, and the adults flew off from these in large numbers when the canes were shaken. On August 26th a large number of apple branches in the flat orchard were very carefully examined, and we could not find any egg-blisters of E. mali. On September 13th, however, another examination on some of the trees close to the alfalfa disclosed the ege-blisters of E. mali present in considerable numbers. It seems probable that oviposition had begun several days before this date. The blisters were not, at this time, nearly so numerous as they were last fall after oviposition had ceased; this showing that adults were still laying at this date (Sept. 13th). On September 17th the clover fields and alfalfa fields were swept, and it was found that EF. mali were far less numerous than they had been before this date. In connection with the work on Empoasca, the accompanying chart, constructed by Mr. Stafford, shows the relative abundance of adults and nymphs, indicated by his sweepings of clover upon thirteen dates. This is numerically expressed as follows: INJURIOUS INSECTS ‘9T “SIA ‘S}[Npe ‘taMo, ‘sydurdAu ‘ouly, staddy ‘gsa]ep JUuedoyrp ye syduicu pue sioddoy Jroet y[Nnpe Jo vouepuNnge 9AT}eIvdWI0D Surmoys JAIvYD “paloyers OF 1909 AND IQIO. 37 38 INJURIOUS INSECTS OF 1909 AND IQIO. Date— Adults Young Ml yes oat ereae ananaealens croiehegeaaceeare Lota 4.3 les Uta ate Sis es cteenera a carpentoe cas in aoeestene Ato ahots 6.2 6.8 TU PSs bose ioteke eons at rocweee 6.4 33.0 AI /UOL Ite Pal CO) Ween eee ese ood rks avin hak Abate 2.0 18.2