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HOWARD, Entomologist and Chief of Bureau. -PLANT-BUGS INJURIOUS TO COTTON BOLLS. BY A. W. MORRILL, Pu. D., ~ Entomologist of the Arizona Horticuliural Commission and of the Arizona Agricultural gna Lexperiment Station. IssueD JuNE 14, 1910. ws Z i y Tashi c NIK a ~ += ~ ~-WASHINGTON: Pc ‘ GOVERNMENT PRINTING OFFIOR, Mee eee xt 10-1 0% Bul. 86, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE | SOME OF THE MORE IMPORTANT PLANT-BUGS WHICH ATTACK COTTON BOLLS. Fig. 1.—The conchuela (Pentatomaligata). Fig. 2.—The brown cotton-bug (Euschistus servus). Fig. 3.—The green soldier-bug (Nezara hilaris). Fig. 4.—Thyanta custator. Fig. 5.—Acantho- cephala femorata. Fig. 6.—The leaf-footed plant-bug (Leptoglossus phyllopus). Fig. 7.—The bordered plant-bug (Largus succinctus). Fig. 8.—The cotton stainer (Dysdercus suturellus). Fig. 9.—Oncopeltus fusciatus, showing egg of Tachinid parasite attached to upper side of head between the eyes. All enlarged one-third. (Original.) i] Pao. DEPARTMENE OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN No. 86. L. O. HOWARD, Entomologist and Chief of Bureau. PLANT-BUGS INJURIOUS TO COTTON BOLLS. BY A. W. MORRILL, Pu. D., Entomologist of the Arizona Horticultural Commission and of the Arizona Agricultural Experiment Station. IssueD JUNE 14, 1910. diel Se stv uc ise hi .) Sons .. = 3 ase i ez 5 i aii Di | AY eine 3} IP WASHINGTON: GOVERNMENT PRINTING OFFICE LALO. BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Maruatt, Assistant Entomologist and Acting Chief in Absence of Chief. R. 8. Currron, Executive Assistant. W. F. Tastet, Chief Clerk. F. H. CaitrENDEN, 1n charge of truck crop and stored product insect investigations. A. D. Hopxtins, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. F. M. WEBsTER, 1n charge of cereal and forage insect investigations. A. L. QUAINTANCE, i charge of deciduous fruit insect investigations. E. F. Puuures, in charge of bee culture. DON: Rocuns, in charge of preventing spread of moths, field work. Rouia P. Curriz, in charge of editorial work. MABEL CoLcoRD, librarian. SOUTHERN FIELD Crop INSECT INVESTIGATIONS. W. D. HuNTER, in charge. W. D. Pierce, R. A. Cusuman, C. E. Hoop, E. 8. Tucker, engaged in cotton boll weevil investigations. F. C. Bisuopp, J. D. MircHeitt, H. P. Woop, engaged in cattle tick life history investi- gations. A.C. Moraan, G. A. RunNER, S. E. Crump, engaged in tobacco insect investigations. D. L. Van Dine, engaged in sugar cane and rice insect investigations. F. C. Pratt, engaged in cactus insect investigations. 2 LETTER OF TRANSMITTAL. - U.S. DEPARTMENT OF AGRICULTURE, BurEAvU OF ENTOMOLOGY, Washington, D. C., December 13, 1909. Sir: I have the honor to transmit herewith for publication a manuscript entitled ‘‘Plant-bugs Injurious to Cotton Bolls,” by Dr. A. W. Morrill, entomologist of the Arizona Horticultural Commission and of the Arizona Agricultural Experiment Station, Phoenix, Ariz. The work upon which this manuscript is largely based was con- ducted by Doctor Morrill and this report prepared and submitted by him while he was a special field agent of this Bureau. It grew out of an investigation of the so-called ‘‘conchuela”’ of northern Mexico, a plant-bug which has proved to be especially destructive to cotton bolls. The same insect pest was studied further in western Texas, and other species were investigated both there and in other sections of the United States. Although the injury to the cotton crop effected by plant-bugs is of course secondary to that caused by the boll weevil, yet itis by no means inconsiderable and renders necessary a knowledge of the life histories of these injurious bugs and of the best methods for their control. I would therefore recommend the publication of this manuscript as Bulletin No. 86 of the Bureau of Entomology. Respectfully, L. O. Howarp, | Entomologist and Chief of Bureau. Hon. James WILson, Secretary of Agriculture. PR EAA: Damage by the boll weevil has brought into prominence many other insects which attack the cotton plant, the work of which has been largely overlooked. Among the most important of these minor insects are various species of plant-bugs. Many of these have been known as enemies of the cotton plant for some years, but they have received only slight attention from economic entomologists. When their damage is added to the injury done by the cotton boll weevil, still further reducing the crop, they become of such importance that full knowledge of their habits and life history is demanded. The studies upon which this bulletin is based were conducted to add to our knowledge of the biology of an important group of insect pests and of the most practical and efficient methods by which they may be controlled. The plant-bugs with which this bulletin deals, in addition to destroy- ing many cotton bolls and squares, cause more or less staining of the fiber, thus reducing the quality. A large portion of the so-called “spotted cotton,” which everywhere suffers a considerable reduction in price below unspotted cotton, is due to the work of plant-bugs. The damage is not confined to any restricted areas, though different species of bugs occur in different parts of the cotton belt. Therefore the damage that is done by these insect pests every year is by no means inconsiderable. The work accomplished by Doctor Morrill and reported on in this bulletin grew out of an investigation of the Mexican conchuela (Pentatoma ligata Say) in northern Mexico. An opportunity was there afforded for a rather careful study of the life history and habits of a representative of the large family of plant-bugs. This was followed by investigations of the same species in western Texas and of other species in other localities. As a result Doctor Morrill’s work gives rather complete’ knowledge of insects the work of which will assume new importance as the area of boll-weevil infestation continues to increase in the United States. For valuable notes and data on various subjects concerning the conchuela, and especially on its seasonal history, for hearty coopera- tion in experimental work, and for the facilities which aided in 5 6 PLANT-BUGS INJURIOUS TO COTTON BOLLS. conducting field observations, much credit is due Mr. J. P. Conduit and Mr. J. A. Vaughan, of the Tlahualilo Agricultural Company, Tlahualilo, Durango, Mexico. Mr. B. F. Butler of the same com- pany, manager of the Hacienda San Fernando, Lerdo, Durango, Mexico, furnished valuable information concerning the comparative erading of the cotton staple at infested and uninfested sections of the Laguna district. All of the investigations reported in this paper were conducted by Doctor Morrill, except where special credit has been given in the text. Of the original text figures, numbers 2,3, 4, 5, 6, 10, 11, 15, 16, 17, and 18 were drawn by Mr. J. F. Strauss, of this Bureau, while the remainder are the work of the author. W. D. HuntEr, In Charge of Southern Field Crop Insect Investigations. ’ CONTENTS. Page. Historical review of published writings on plant-bugs injurious to cotton bolls. . aa PME MEE GMO CRAG ONG fo 2 cree 2 4 aia ss Sates Rae ee te Pe Se ee eee 13 Paemrcraninjury: Dy plant-bugsss:.2ss.0. Ss 220s oP ge ee os 13 moun ot damage to cotton by plant-bugs:..2. 220..2120 5)... 22...--. 22 20 Plgnt-bugs as disseminators of plant diseases. ...-..-..25--.2...-.2+------ 23 fine manchuela (Pentatoma ligata Say)...2:.-/..22.--02 2-22.22 --.-- see sees 23 gembleshonys. 2.4... .2ad2- 2 2 es «: CAT at arta ee Rell ME ee Me Ree OA eo a2 23 LOLS DU noes Bs athe em eS Oye iia Aa an ale SI oR an ER 24 LA DOG! TORIES ah ae Re ee A ee ei eae ee Se bkRceecindl LA e Is gyal 25 Nema CHa s yee ene Met eeg TN meertd nd Lee Pe kT eee Ss tes 25 Ree BM voMne eres te Gee eter Se eee tet SOP See ee ee ae 29 ene OOMStGye etn Mone c ree ee. See ES ee 29 Seer rte eae & icecks ARMM IETS Me oe re a ee Ss 29 Period between maturity of adults and beginning of egg laying... 29 emEOd WELIOMM mares case re en se en tee ioe ce hn oie te ok wy eee 5 30 PRO PORMOMROMSE RES Aa tae Shee oth set ad eee nel eee oe ts ecradooe 32 VASID GORE MIE Gad Sane Bien ete, ee a Ae ie eRe NR ee ee gg 5 Relation of temperature to activity of adults.................--- 35 DEAE Nymph. first instars... ..ieos- ses ee s--+-! ohne ecouchmels. NN ymapm. second. instar. 55. 0ss.< 2... +... l.- 2 a7 cue eanenten. Nymph, third Instat... 252.2 vec ne. e dese eee ese e se 16 18 18 26 26 27 27 28 10 BiG: p: . The conchuela: Nymph, fifth imstar -/-2...2--.4:22-_7. . Diagram of a portion of the Tlahualilo Cotton Estates................ . Telenomus ashmeadi, an important parasite of the conchuela (Penta- PLANT-BUGS INJURIOUS TO COTTON BOLLS. The conchuela: Nymph, fourth instar toma ligaia).- 2.00628 eas Seba se ee es ee ee . Plan for the construction of a collecting can for use in hand-picking cotton plant-bugs....-- so9i. 2-42-54 5 cee eee eee . The grain bug (Pentatoma sayi): Nymph, first instar................- . The grain bug: Nymph, fifth instar: 7-5... 2-22.25. --2-2oe see = . The brown cotton-bug (Euschistus servus): Nymph, first instar. ....-. . The brown cotton-bug: Nymph, fifth, instar. _.2.23..20. = ae . The green soldier-bug (Nezara hilaris): Nymph, first instar.....--..--- . The green soldier-bug: Nymph, fifth instar; light and dark types.... . Nezara viridula: Nymph, fifth instar; ight and dark tYPes..n2 eee . Chyanta custator:, Nymph, first.anstar..-2 5. =. 223 . Thyanta custator: Nymph, fifth instar; light and dark types.-....-.-.--. . The leaf-footed plant-bug Crees phyllopus): Adult. : . The northern leaf-footed plant-bug (Leptoglossus oppositus): Tee a . The northern leaf-footed plant-bug: Nymphs. ......-..-..--.--..---- . Trichopoda pennipes, a Tachinid parasite of Coreid plant-bugs. --..-.-- . The cotton leaf-bug (Calocoris rapidus): Nymphs and adult.......... . The bordered plant-bug (Largus succinctus): Nymph, first instar. --. . . The bordered plant-bug: Nymph, fifth instar................------- PLANT-BUGS INJURIOUS TO COTTON-BOLES. HISTORICAL REVIEW OF PUBLISHED WRITINGS ON PLANT-BUGS INJURIOUS TO COTTON BOLLS. For reasons hereinafter explained, comparatively little has been written concerning insects of the suborder Heteroptera (better known as plant-bugs) in relation to their damage to cotton. The earliest records of this kind are found in the writings of Townend Glover. In the U. S. Agricultural Report for 1854,¢ in a short article on insects infesting the cotton plant, Glover writes: ‘‘Several insects (Pentatoma and Anisoscelis) were very abundant in the cotton fields, both on the bolls and leaves, which have been accused of piercing the young bolls for the sake of the juice, but as none were observed in the act it can not be stated definitely whether they actually do harm or not, before their habits have received further investigation.” In the report published for the following year (1855)° the same writer gives a brief account of many insects which frequent the cotton plant, and refers to the rotting of bolls as possibly due to the feeding of plant-bugs, mentioning especially two Pentatomids, one appar- ently Nezara hilaris Say, and the other apparently of the genus Euschistus, as also a Coreid, which, judging from the description and drawing, is Leptoglossus phyllopus L. The cotton leaf-bug (Calocoris rapidus Say), which in 1903 and 1904 proved to be of considerable importance as a cotton pest in certain sections of Texas, was here first recorded in this connection and nearly two pages in this report were devoted to the well-known “red bug”’ or cotton stainer (Dysdercus suturellus H. Schf.), an account being given of its occurrence and depredations on cotton in Florida. The report for the year 1858° contains additional notes on this latter pest. No writings concerning Heteropterous insects attacking cotton bolls, published between the date of this last-mentioned report and that for the year 1875, are known to the writer. In Glover’s report for 1875¢ the cotton @ Agricultural Report for 1854, p. 61. 6 Agricultural Report for 1855, pp. 86-87, 93-95, 103-105. ¢ Agricultural Report for 1858, pp. 271-273. @d Report of Commissioner of Agriculture for 1875, p. 124. 11 12 PLANT-BUGS INJURIOUS TO COTTON BOLLS. stainer is again referred to. The same author in 1878¢ figures and mentions certain Heteroptera found on cotton, including WNezara pennsylvamca De Geer, Euschistus punctipes Say, and Leptoglossus phyllopus Li. Professor Comstock, in his report for 1879,® reviews what was then known about the cotton stainer and gives an account of its first appearance as an orange pest, stating that the principal injury to this fruit was done where cotton was planted in close prox- imity to the orange groves. In Professor Comstock’s Report on Cotton Insects,° published in 1879, the green soldier-bug (Nezara hilaris) is credited with being more or less beneficial in cotton fields, owing to its reported destruction of cotton worms. The report of Mr. E. A. Schwarz of the destruction of cotton in the Bahamas by Dysdercus suturellus as observed by him in 18794 is of special interest on account of his description of the injury caused by this insect, and will be referred to again in discussing the nature of the injury caused by Heteropterous pests. In 1889 Riley and Howard® gave the most complete account of the cotton stainer that has been published. Insect Life, in 1890,‘ contains a brief note to the effect that a corre- spondent of the Division of Entomology had sent in specimens of the green soldier-bug (Nezara hilaris), reporting that they were dam- aging cotton in Florida. Mr. F. W. Mally, in 1893,9 in his report on the bollworm of cotton briefly described injury to cotton by Calocoris rapidus and Largus cunctus H. Schf. In a paper entitled ‘‘Notes on cotton insects found in Mississippi,” published in 1895,” the late Dr. Wm. H. Ashmead gave brief notes on a number of Heteroptera which he had collected on cotton, including several actually observed feeding on the boll. A report of damage to cotton in Peru by one of the cotton stainers (Dysdercus ruficollis) was noted by Dr. L. O. Howard in 1900,‘ in a Miscellaneous Results bulletin of this office, and a similar report of damage by the St. Andrews cotton stainer in Cuba was noted by Mr. W. D. Hunter,’ in a bulletin of the same series pub- lished in 1902. Extensive damage to cotton in Mexico in 1903 by the Pentatomid bug known as the conchuela (Pentatoma ligata Say) led the following year to a preliminary investigation of this pest, which was reported by the author in a previous bulletin of this a Manuscript Notes from My Journal, Pl. XVI. b Report of Commissioner of Agriculture for 1879, pp. 203-204 ¢ Report on Cotton Insects, p. 167. 4 Report on Cotton Insects, pp. 348-349. ¢ Insect Life, Vol. I, pp. 234-241. F Insect Life, Vol. III, p. 403. g Bul. 29, Div. Ent., U.S. Dept. Agr., p. 31. hInsect Life, Vol. VII, pp. 320-321. tBul. 22, Div. Ent., U.S. Dept. Agr., p. 100. j Bul. 38, Div. Ent., U. 8. Dept. Agr., p. 106. NATURE OF INJURY. 13 Bureau.? Prof. E. D. Sanderson during the same year conducted observations on miscellaneous cotton insects in Texas, including sey- eral of the Heteroptera. The results of his work on this subject have been incorporated in a Farmers’ Bulletin of the Department of Agriculture® and in a regular bulletin of this Bureau.° Plant-bugs attacking cotton in the Bismarck Archipelago and in German East _ Africa have been considered by Dr. Th. Kuhlgatz in a publication of the Berlin Zoological Museum in 1905.4 This report contains but few field notes outside of records of food plants. A valuable report on cotton stainers in the West Indies was published by Mr. H. A. Ballou in 1906. GENERAL CONSIDERATIONS. NATURE OF INJURY BY PLANT-BUGS. In beginning the investigation of plant-bugs destructive to the cotton boll one of the first steps found to be necessary was a study of the nature of the injury itself so that it might be identified positively or at least with reasonable certainty. As a result it has been more and more impressed upon the author that to the lack of an accurate knowledge of this subject is due the almost complete ignoring of these insects as cotton pests. In general the connection between the insects and the damage which results from their attacks is very obscure to the casual observer, and consequently seldom suspected. Even to an entomologist the damaged boll when dry gives by itself no direct evidence of the cause of its condition without reference to a field demonstration of the relation between the insects and the stained or shriveled locks. PUBLISHED DESCRIPTIONS OF THE EFFECT OF PLANT-BUG ATTACK ON COTTON BOLLS. In Glover’s brief publication on this subject in the U. S. Agricul- tural Report for the year 1855 is to be found the earliest mention of plant-bugs—Pentatomids and Coreids—as possible producers of ‘“‘rot’’ in cotton bolls and also of the nature of injury by the cotton stainer. This discussion, of the damage to cotton caused by the Coreidz, is the most complete that has been published, and in fact all later references to the subject are based directly or indirectly upon this except the report of Mr. Schwarz’s observations in the Bahamas -and the recent report by Mr. Ballou. Heretofore it seems to have been the popular belief in Florida that the principal damage to the 2 Bul. 54, Bur. Ent., U.S. Dept. Agr., pp. 18-34. 6 Farmers’ Bul. 223, U.S. Dept. Agr., pp. 20-21. ¢ Bul. 57, Bur. Ent., U.S. Dept. Agr., pp. 44-49. d Mittheilungen aus dem Zoologischen Museum in Berlin, III Band, 1 heft, pp. 31-114. ; e West Indian Bulletin, Vol. VII, No. 1, pp. 64-85, 14 PLANT-BUGS INJURIOUS TO COTTON BOLLS. cotton was through the staining of lint in the open bolls by the excrement of these insects. In this connection it seems well to refer to the common belief among the natives of that part of Mexico where the conchuela has been so destructive, that the damage to the cotton is effected by the voiding of excrement upon the lint and unopened — bolls. The author can state positively that such a belief is unfounded in this instance, and that he is, moreover, disposed to look carefully into the source of all such similar suppositions before accepting them as entirely credible. Glover quotes at length a communication from a Sea Island cotton grower in Florida who shows himself to be a care- ful observer, capable of distinguishing between fact and theory. This correspondent states: ‘‘The pod or boll is perforated by the bug. Whether the staining matter is imparted to the fiber of the cotton during the perforation directly or by a slow process diffusing itself with the sap abounding at the time in the pod is not yet ascertained. I am of the latter opinion, from the fact that almost the entire prod- uct of the boll 1s discolored when it opens, which does not seem at all to cause a premature development.” As opposed to this source of the discoloration Glover merely states: ‘‘It has been stated by other planters that the feeces of the insect produce the reddish or greenish stain.” Three years later the same author states® concerning the injury by the cotton stainer: ‘‘It drains the sap from the bolls by its puncture, causing them to become diminutive or abortive, but the principal injury it does is by sucking the juice of the seed and boll and then voiding an excrementitious liquid, which stains the cotton fiber yellow or reddish, and very much depreciates its value in the market, the stains being indelible.’”’ This description of the injury, as well as the descriptions presented in the later writings of Glover and others on the cotton stainer in Florida, seems to be based on the first account of the insect damage from which the above quotations were made. In 1879 Mr. E. A. Schwarz,° in a report on insects injuring cotton in the Bahamas, refers to the cotton stainer of the Bahamas, later identified as belonging to the same species which occurs in this country. He states regarding its injury: ‘‘It punctures the green bolls, thus preventing them from opening; the bolls wilt and finally dry up, the half-formed cotton and dried-up seeds giving food to a number of other insects; more often the cotton-bug crowds in the half or not quite half open bolls, sucking the seeds, thus preventing the cotton from blowing, or at least renders the cotton yellow and unfit for use.’”’ As these observations extended over a period of less than ten days, they do not disprove the statements of Glover’s a Italics are mine.—A. W. M. b Agricultural Report, 1858. ¢ Report upon Cotton Insects, pp. 347-349. NATURE OF INJURY. 15 correspondent that the discoloration appears as soon as the boll opens. Following the foregoing accounts the next reference to the nature of plant-bug damage, so far as known to the writer, is a brief descrip- tion of damage to cotton in Egypt by a Lygeid, Oxycarenus hyalini- pennis Costa, published in 1890.* This description, which is cred- ited to Dr. E. Sickenberger, states that these insects ‘‘suck the sap from the base of the young pods and from the blossoms and thus prevent their development; they attack also the seeds when they are tender, which results in a diminution of the germinative strength and consequently a diminution in the product of the plant.” A staining of the lint is also mentioned but the exact method by which this injury is brought about is unexplained. The cotton leaf-bug (Calocoris rapidus Say) and the bordered plant- bug (Largus succinctus L.) are reported by Mr. F. W. Mally® to damage cotton bolls, leaving a small, round, black dot at the point of the puncture. He says: ‘The injury nearly always has the effect of causing the boll to ‘flare’ and drop, or if not, then the tuft of cotton in that section of the boll becomes stained.’’ The first accounts of damage to cotton bolls, with Heteropterous insects deter- mined as the cause by definite experimental work, were published in 1905, Prof. E. D. Sanderson describing the injury caused by Calocoris rapidus, and the present writer the injury by the conchuela, Pentatoma ligata Say. Concerning the former Professor Sanderson ® says: ‘‘It punctured the squares and young bolls, either causing them to drop or making the bolls shrivel or decay where punctured. The punctures in the boll are indicated by small round black spots resembling dis- eased places, which gradually become larger and sunken.’ The fullest consideration heretofore published of the nature of the injury caused by the cotton stainers is found in the recent paper by Mr. H. A. Ballou, previously referred to. This author reports no per- sonal observations concerning the staining of cotton lint by the excrement of the bugs but mentions the probability of injury through the feeding of the insects on immature bolls and, later, on the seed at time of the opening of the bolls. EXTERNAL EVIDENCE OF PLANT-BUG INJURY. As the leaf-bug (Calocoris rapidus) is sometimes present in con- siderable numbers in cotton fields where no external evidence of injury such as described by Professor Sanderson can be found, it seems likely that the sunken spots on the outside of the boll, resem- bling some diseased condition, are not a necessary accompaniment of @ Insect Life, Vol. III, p. 68, 1890. 6 Bul. 29, 0. s., Div. Ent., U. S. Dept. Agr., p. 31, 1893. ¢ Farmers’ Bulletin 223, p. 20, 1905, 16 PLANT-BUGS INJURIOUS TO COTTON BOLLS. this insect-damage (PI. II, fig. 5). However, the fact that they have been produced in some cases differentiates the injury by this Capsid from that of all Pentatomids, Coreids, and Pyrrhocorids which has come under the writer’s observation. Investigations during the past two years in many sections of Texas and in northern Mexico with representatives of these three last-mentioned families of Heteroptera have failed to show a direct connection between spots of any kind on the outside of the carpels of the injured bolls and the insect’s punc- tures. In nearly all cotton fields bolls can be found which are marked with reddish or brownish spots (PI. II, fig. 8), more frequently seen on the parts of the boll not covered by bracts, and never showing on the inside of the carpels. It is apparently an evidence of a physiolog- cal disorder of little or no consequence, but in some cases these spots have appeared to bear a relationship to the condition of the developing lock. To determine if any such relationship existed in the case of green bolls damaged by plant-bugs, 100 bolls were examined, with the following results: Average number of spots in 25 bolls with slightly stained locks...-........... 2. 24 Average number of spots in 75 bolls with badly stained locks.................. 3 Percentage of badly stained bolls without spots... 2... 2... =... cope eee 10 Percentage of slightly stained bolls without spots............ =. 2.2 eee 46 A second lot of green bolls picked from plants on July 11, 1905, was . examined and the results are here presented in tabular form. TABLE I.—Relation of external spots to plant-bug injury of cotton bolls. | Number of | Number of Number of external spots. cue of bolls dam- | bolls un- aged. injured. More than:one>. wo ses25 52 ean ce eee ee eee ae 17 17 0 (Sine EET Ie el ee err ee we Beco te RSH! Lo od ee 11 9 2 Wone ib eee oe See Bates CE ee Ne ree 10 7 3 Potale eh sa ah ee ee eee 38 33 | 5 The punctures may be through the spot, but this is entirely acci- dental. One boll of the above lot showing over 60 conchuela punc- tures was found to have but three small external spots, while the carpel of the lock most severely damaged was entirely free from dis- coloration. Among those examined which showed but one external spot, several were as badly damaged as any of the entire number. From the foregoing observations we may conclude that the spots here referred to with which every cotton grower is familiar do not bear a direct relation to punctures by plant-bugs, for the spots may be present on bolls which show no punctures, which in all cases are detect- able when present as hereafter described, and may be absent on badly damaged bolls. They are shown, however, to have a secondary Bul. 86, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE II, EFFECTS OF PLANT-BUG ATTACK ON COTTON BOLLS. Fig. 1.—Boll with section of carpel removed to show plant-bug injury. Fig. 2.,—Portion of full- grown cotton boll, showing lock of cotton ruined by destruction of seed at apex by Thyanta custator, Fig. 3.—Lint partly removed from seeds to show discoloration by cotton stainer (Dys- dercus suturellus); a, Seed and attached lint from uninjured boll; b-c, same from boll dam- aged by cotton stainer, showing lint stained deepest close to seed. Fig. 4.—Decay of seeds in immature cotton boll as a result of feeding by plant-bugs; no external evidence of injury. Fig. 5.— Exterior of cotton boll injured by Calocoris rapidus. Fig. 6.—Cross section of immature cotton seed damaged by Pentatomid bugs. Fig. 7.—Inside of carpel of cotton boll, showing feeding punctures by plant-bugs. (Arrows point to punctures without proliferation.) Fig. 8.—Cotton boll showing external spots referred to on page 16. (Original.) NATURE OF INJURY. 17 relationship in that they occur with greater frequency on bolls injured by plant-bugs than on those entirely free from injury from this source. Although no external discoloration in the form of spotting of the bolls is known to result directly from the attacks of the representa- tives of the Heteropterous families thus far studied, and included in this discussion, there is frequently present more or less reliable external evidence of damage. Bolls when severely attacked by plant- bugs may flare, turn yellowish, become flaccid, and finally fall to the © ground. This has been observed to take place in bolls as large as 134 inches in diameter, although it more often occurs in bolls which have attained less than one-half of the normal mature size than in larger bolls. Occasionally a deformity results from the destruction of one lock when the boll is quite small, but this frequently occurs when there is no evidence to connect the deformity with plant-bugs. In addition to these physical changes in the boll, it has been observed with several of the plant-bugs that damaged bolls may be detected in many cases by the yellowish stain produced on the bracts and carpels by the liquid excrement. INTERNAL APPEARANCE OF BOLLS DAMAGED BY PLANT-BUGS. Description.—Plant-bug injury to cotton bolls can be positively determined only by means of an internal examination. This subject was treated in the author’s report® of preliminary investigation of the conchuela in northern Mexico, but additional observations allow of a more complete consideration at this time. While these observa- tions are for the most part based on the conchuela, it has been found that the same effects result from the attacks of the other representa- tives of the Pentatomide, as well as the representatives of Coreidz and Pyrrhocoride upon which studies have been made. The most essential factor in determining injury to cotton bolls by these plant- bugs is the appearance of the inner side of the carpels (PI. IJ, fig. 7), where the point of entrance of the insect’s sete is marked by a minute dark spot surrounded by a watery or blisterlike, bright-green area, contrasting distinctly with the light, dull-greenish background. In many cases, particularly in bolls three-quarters grown or more, these blisterlike areas increase to a diameter of 4 or 5 millimeters, but in other cases, more especially in small, rapidly growing bolls, a physio- logical reaction in the form of a proliferation of plant tissue takes place. This proliferation (PI. III, figs. 6-8) is of the same nature as that which results from the puncturing of the carpels of the bolls by boll weevils, described by Hunter and Hinds in a previous bulletin of @ Bul. 54, Bur. Ent., U.S. Dept. Agr., pp. 29-30, 1905. 22348—Bull. 86—10——2 18 PLANT-BUGS INJURIOUS TO COTTON BOLLS. this Bureau.¢ That this abnormal growth may be caused by the punctures of Heteropterous insects was first pointed out by the author in his report of preliminary investigations of the conchuela.® Since then, in the course of more extended investigations of this and other Heteropterous cotton pests, incidental observations on this point have been made by the writer, a summary of which will be found in a publication by Dr. W. E. Hinds dealing with the relation of the proliferation to the cotton boll weevil.“ When caused by the boll weevil, this growth can be easily distinguished from that caused by Heteropterous insects by the distinct open puncture which extends through from the outside of the carpel. The entire inner side of the carpels of bolls damaged by plant-bugs is frequently found on exami- nation to present a rough or papulous surface due to the fact that the punctures are so close to one another that the proliferous growths _ merge together. At Tlahualilo, Durango, Mex., on July 17, 1905, an examination of 100 injured bolls revealing over 4,000 punctures by plant-bugs (practically all by Pentatoma ligata) developed the fact that 34 per cent of the punctures had resulted in proliferation. On November 1, 1905, an examination of 25 bolls at Dallas, Tex., from a field -where three species of Pentatomide (Nezara hilaris, Euschistus servus, and Thyanta custator) occurred in considerable numbers, gave the following results in regard to proliferation, using the lock as the unit: Tasie I1.—Proliferation on inside of carpels cf locks fed upon by Pentatomids. Locks. Size of _bolls Number | Percent (diameter). Number.| Showing | showing re Slightly | Unin- ‘| prolifera- | prolifera- ae 2 injured. | jured. tion. tion. 8S. Inches. . gt 60 42 | 70 39 g 0 cae 40 i 27 8 3 a2 Total..... 100 Rega My bell chy | 47 6 2 | a Inside carpels showing three and four punctures, respectively—no apparent injury. The objective point of the attack by insects investigated is the seed, which they are able to reach with little difficulty by means of the threadlike organs of their mouth-parts, except in large, nearly mature bolls which are protected by the resistance offered by the lint. Except in the larger sized bolls, therefore, a blisterlike spot or prolif- a Bul.'51, Bur. Ent., U.S. Dept. Agr., 1905. 6 Bul. 54, Bur. Ent., U. 8. Dept. Agr., p. 29, 1905. ¢ Bul. 59, Bur. Ent., U.S. Dept. Agr., p. 29, 1906. Bul. 86, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE III. EFFECTS OF PLANT-BUG ATTACK ON COTTON BOLLS; EGG AND PUPARIUM OF TACHINID PARASITE. Fig. 1.—Locks of a cotton boll shriveled by the conchuela. Figs. 2-5.—Small Sea Island cotton bolls destroyed by the cotton stainer. Fig. 6.—Nearly mature Sea Island cotton boll opened to show damage by cotton stainer. Fig. 7.—Same with seeds and lint removed to show feeding punctures and proliferation due to feeding by cotton stainer. Fig. 8.—Cotton boll showing two locks damaged by four and six feeding punctures, respectively, by the green soldier-bug (Nezara hilaris). Fig. 9.— Head and thorax of the conchuela, showing egg of Tachinid parasite, Gymnosoma fuliginosa, attached to side of prothorax at left. Fig. 10.—Puparium of Tachinid parasite, Gymnosoma fuliginosa. (Original.) Bul, 86, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE IV. A COTTON PLANT SHOWING THE BOLLS INJURED BY THE CONCHUELA. The cotton plant shown bears 76 bolls, all but 10 of which have been destroyed by this insect. (Original. ) NATURE OF INJURY. 19 eration on the inner side of the carpel, such as has been described, indicates an injury to the seed or discoloration of the lint directly opposite. When a seed of a rapidly growing boll is fed upon at first the stimulation, probably partly mechanical and partly due to salivary fluids of the bug, causes an increase in the flow of sap to the injured seed, causing a characteristic watery appearance. The seed after- wards gradually becomes discolored (PI. II, figs. 4,6) and proliferous tissue is extruded from it in some cases. Punctures near the tip of the lock are most effective in destructiveness; in one case (PI. III, fig. 8) 4, 6, 16, and 10 punctures per lock, respectively, were found to have produced proliferation from the seed nearest the tip of the boll in each lock and would have prevented the opening out of the cotton if it had been allowed to mature. This is equivalent to complete destruction of the boll. The lint surrounding the point where the insect’s mouth-parts enter turns yellowish, and, if the injury is severe, finally becomes a dirty brown and decays (Pl. II, figs. 1, 2; PI. III, figs. 1-8), which probably is the condition Glover referred to as ‘‘the rot.” As the great majority of the punctures are made on the outer half of the bolls, it is there that staining is most frequently found. In general bolls damaged by plant-bugs when open (PI. III, figs. 1-5; Pl. IV) are characterized by shriveled locks and only partial spreading of the carpels. The entire lock may become a brownish shriveled mass or the shriveling may be confined to the outer tip. Again, locks may be perfect except for a small stained patch of lint, which, however, might offset the value of the unstained product. Seeds in nearly mature bolls may be destroyed without the surround- ing lint becoming badly stained. Consequently where Heteropterous cotton pests are abundant, there is a reduction in the percentage of seed capable of germinating. This phase of the subject of plant-bug damage has received no especial attention. Proof that described wnjury rs due to plant-bugs.—The evidence that plant-bugs cause injury such as described above amounts to positive proof. Sufficient evidence was given by the author in a previous report and, although much more might be added, it is unnecessary to more than summarize the facts there presented: 1. In a field where the number of conchuelas averaged about 15 per acre and the number of other plant-bugs was a negligible quantity, a specimen of the species named (Pentatoma ligata Say) was known to have fed on a single boll for over 36 hours. After several days, during which no bugs were found on this plant, the 15 bolls found on this plant were cut open and examined, with the result that only the one upon which the insect was known to have fed showed the injury described. 20 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 2. In the same field two plants upon which 4 and 3 adult conchuelas, respectively, were found, neighboring plants in all directions, being free from the pest at the time, were found to be injured to the extent of 7 bolls out of 15 examined, and 18 bolls out of 20 examined, respec- tively, while as a check the bolls on the next adjacent plant in the row to each of the foregoing were examined and but 3 injured bolls were found out of a total of over 30. 3. The injury to the bolls which has been described as due to plant- bugs was invariably found in sections of a cotton plantation com- prising 27,000 acres, where the conchuela was also found; but in a section where no plant-bugs could be found, although careful search was made for them, no injury of this kind was observed. 4. Cage tests, consisting in the confinement of several adult con- chuelas on two plants in a field where no plant-bugs of any kind could be found and where an examination of many bolls indicated entire absence of the supposed plant-bug injury, resulted in 20 bolls of a total of 34 on the caged plants showing the injury a few days later when an examination was made. AMOUNT OF DAMAGE TO COTTON BY PLANT-BUGS. It is very probable that each year since cotton has been grown in this country certain localities have suffered from injuries by plant- bugs to the cotton bolls. The cotton stainer (Dysdercus suturellus) for many years has been the most serious enemy with which the grow- ers of Sea Island cotton in Florida have had to contend, and the same pest Mr. Schwarz in 1879 (1. c.) declared to be the most formidable enemy of cotton culture in the Bahamas, making questionable the possibility of continued cotton growing on those islands. Professor Sanderson’s reference to the damage by the leaf-bug (Calocoris rapi- dus) shows this insect to be capable of considerable destruction to cotton bolls, although no estimate of the amount destroyed has been made. In the Laguna District of Mexico—the leading cotton-growing sec- tion of that Republic—the conchuela accompanied by related pests of less frequent occurrence has been more or less destructive to cotton during the past few years. A specimen of the insect named was sent to this Bureau in August, 1902, from Mexico, by Dr. A. Dugés with the note that it was injurious to cotton at San Pedro de la Colonia, Coahuila, Mexico. In 1903 the same pest attracted considerable attention on account of its unusual abundance in the cotton fields of the Laguna District, particularly those near Tlahualilo, a settlement located in the State of Durango about 50 miles from San Pedro de la Colonia. After investigation by the author it was conservatively ! AMOUNT OF DAMAGE TO COTTON BY PLANT-BUGS. PAL estimated that the damage to the crop for the season 1903-4 was between 10 and 15 per cent. This loss on the one plantation accord-- ing to this estimate was between 1,200 and 1,500 bales. A study was made of the losses occasioned by these pests in 1905 on the above-mentioned plantation, and the results in detail are considered under the subject of ‘‘Destructiveness” of the conchuela. Briefly, _ this damage on the entire plantation approximated between 5 and 10 per cent, and for one section of 120 acres where the bugs had been most abundant, the destruction as estimated December 4—6, 1905, amounted to 30 per cent of all bolls, including unopened bolls, and 41 per cent of all bolls open at that time. In this country damage by plant-bugs, with the Seontiod of that by the cotton stainer, has never attracted so much attention as has that by the poueinela in Mexico. Nevertheless, after the character- istics of plant-bug injury have been brought to one’s attention, a per- son is generally impressed with the frequency with which it is met in the cotton fields. The appearance of the conchuela as an enemy of miscellaneous crops in western Texas, near Barstow, in 1905 led to an investigation, in connection with which estimates were made of the damage of the insect to cotton in that locality. As has been stated in a paper dealing with this outbreak, it was estimated that about 10 per cent of the cotton was destroyed near Barstow in 1905. In one field on August 11, 30 per cent of the bolls had been ruined, but the disappearance of the majority of the insects and the continuance of the fruiting of the plants resulted in the percentage of injury being ultimately reduced by one-half. Plant-bugs occur in cotton fields in the northern half of the State of Texas in much greater abundance than in the southern half, and in 1905, special attention having been given for the first time to the occurrence of plant-bug injuries, it was evident that the aggregate losses from this cause must have been large. It is impossible to ap- proximate the total loss chargeable to the work of plant-bugs in 1905, but it is almost certain that for northern Texas an estimate of 4 or 5 per cent of all bolls is not too high. As a matter of fact the writer’s personal examinations in many cotton fields in the section of Texas referred to indicated that this estimate is much too low. Plant- bugs (Pentatomids) were especially abundant near one corner of a 60- acre cotton field at Dallas, Tex., used for experimental purposes by this Bureau. On September 9, 1905, 43 green cotton bolls were picked at random in the section of the field referred to, and of these 29, or 68 per cent, were damaged by the bugs, about 50 per cent being ruined and the others showing badly staimed lint. On November 4, 25 bolls were picked at random in a section of the field where these 22 PLANT-BUGS INJURIOUS TO COTTON BOLLS. insects had been abundant, and the results of the examination are summarized in the following table: - TaBLe III.—Injury by plant-bugs to cotton bolls. BOLLS. Diameter. Number. Uninjured. | Slightly-injured. Inches. SE, TIE iat oe A crete eee fe 15 al 0 (2 Pee IO os cians NE Seis Goo Sees 10 1 | b2 Total...\: 7 huss eesetee eee ee ee eee 25 2 2 LOCKS. Destroyed by |Slightl d| Destroyed b | estroyed by |Slightly injure estroyed by |. ae Numaiber- bugs. | by bugs. weevils. Uninjured. 60 45 8 1 6 40 15 11 2 AZ 100 60 19 3 18 FEEDING PUNCTURES. Number in | Number in|} Number in eaeeaes per| Average Bed eee per| A verage per Total. destroyed | slightly in-| uninjured | destroyed | slightly in-| uninjured | destroyed locks. jured locks.; locks. lock. jured lock. lock. boll. 366 346 20 0 ed 2.5 0 26 300 186 82 32 12.4 7.0 2.6 30 666 532 | 102 32 8.9 5.3 1.8 28 | ae eee Slightly injurea | Unin- _ Destroyed bolls. Slightly injured bolls. | Destroyed locks. 8 I avi J jured : locks | Maxi- Mini- Maxi- Mini- Maxi- Maximum Minimum | Maximum | Minimum| mum mum mum mum mum number of | number of | number of |numberof| number | number | number | number | number punctures. | punctures. | punctures. |punctures.| of punc- | of punc- | of punc- | of punc- | of punc- | tures tures tures tures tures 69 | i oe | aps ERE ae nh i || I ah Ree SA 20 1 5 Les eee ee ee Site 15 55 16 22 4 16 1 10 a Two locks destroyed by boll weevil larve. b Including one boll with 55 feeding punctures by bugs, lint nike slightly stained at time of examination. The data given in Table III will serve as a guide to the relation between plant-bug punctures and the damage which results, as well as an example of a condition which may be occasionally met with in cotton fields of northern Texas where large numbers of plant-bugs — are concentrated in small areas. Fortunately such occurrences are not common and are generally restricted to small areas where the surroundings are favorable for the breeding of the bugs in large numbers. THE CONCHUELA. 98 Due credit has not hitherto been given plant-bugs for their part in diminishing the yield of cotton and lowering the quality of the lint. This failure to connect the injury with the cause, as has been pointed out, is largely due to a lack of understanding of the nature of the injury, as well as to the fact that plant-bugs have always been found in cotton fields and except in rare instances no good criterion for judging the amount of loss has been afforded. Field agents of this Bureau, engaged in investigating cotton insects, frequently have met cotton growers in northern Texas who ascribed the shriveled condition of the locks of bolls damaged by these bugs to dry weather. In Florida some cotton growers have explained damage of this same _kind as due to the prevalence of wet weather. - Summarily it may be stated that locally plant-bugs frequently cause large losses and throughout large sections of the cotton States cause small but appreciable losses which it is important should be determined in a less cursory manner than heretofore. PLANT-BUGS AS DISSEMINATORS OF PLANT DISEASES. Various plant-bugs have been suspected of transmitting fungous and bacterial diseases of plants, but as yet there appears to have been no careful investigation of this matter. That the transmission of the spores of cotton boll anthracnose (Colletotrichum gossypir Southworth) by plant-bugs from one boll to another is possible requires no demonstration. An investigator would rather be con- cerned with the extent to which these cotton-frequenting insects are responsible for the spread of the disease. It is highly probable that the bacillus of the cotton boll ‘“‘rot” (Bacillus gossypinus Stedman) may be disseminated to a greater or less extent by means of plant- bugs whose mouth setz would furnish a means of direct entrance of the organism to the interior of the boll. The entire subject is one which offers a field for interesting and valuable research, but for the present no estimate can be made of the damage to cotton indirectly caused by plant-bugs through dissemination of pathogenic fungi and bacteria. THE CONCHUELA. (Pentatoma ligata Say.) (PP 1. fie. 1) HISTORY. The conchuela ? was described in 1831, but first became known as an insect of economic importance when, in August, 1902, specimens were received from a correspondent of the Bureau of- Be Gales a This is the common name used for this insect by the natives of the Laguna Dis- trict of Mexico. It isa Spanish word meaning “little shell’’ and is based on a fancied resemblance to a shell. 24 PLANT-BUGS INJURIOUS TO COTTON BOLLS. with the note that the species was injuring cotton in the Laguna — District of Mexico at San Pedro de la Colonia, State of Coahuila. In March, 1904, the author was directed by the Entomologist to in- vestigate a reported partial destruction of the cotton crop by an un- known pest in the Laguna District of Mexico. The specific report emanated from a large plantation of between 25,000 and 30,000 acres of cultivated land located in the northern portion of the Laguna District, the headquarters being at Tlahualilo, State of Durango. At the season of the year when the first visit was made, although the cotton stalks were still standing in the fields, it was impossible to establish positively the relationship between the conchuela and the large number of ruined bolls present everywhere on the plantation. The second visit to Tlahualilo from August 30 to September 8, 1904, resulted in this point being definitely determined as well as in the procuring of considerable information concerning the insect and its work. The details of these preliminary investigations were reported on in a previous bulletin of this Bureau.@ The investigations were continued in 1905 at Tlahualilo, where the author of this report spent the month of July and a week in the early part of December. } The conchuela has recently become known as a pest in western Texas, where, in 1904 and 1905, near Barstow, it occasioned con- siderable loss to seed crops of alfalfa, and in the latter season proved, in addition, its destructiveness to miscellaneous crops, including peaches, grapes, peas, and other garden products. The report of the investigation of this unexpected outbreak has been published under a separate title.? DISTRIBUTION. The distribution of Pentatoma lgata is a wide one, the species” occurring rarely in the eastern half of the United States, and with much more frequency in the arid and semiarid regions of the Western States and Mexico. It is probably of considerable significance that hitherto localities where this species has been found to occur in large numbers have been situated in the Lower Sonoran faunal region of the Lower Austral zone. In Texas miscellaneous collections for three years by members of the Bureau of Entomology engaged in cotton boll weevil investigations have not included a single specimen of Pentatoma ligata taken east of the semiarid region or approximately the ninety-eighth degree of longitude. A single specimen in the collection at the office of the Texas state entomologist bears the label Beeville, Tex., which is situated between the ninety-seventh and the ninety-eighth degrees of longitude and is the easternmost a Bul. 54, Bur. Ent., U.S. Dept. Agr., pp. 18-34, 1905. 6 Bul. 64, Pt. 1, Bur: Ent., U.S. Dept. Ace 1907. THE CONCHUELA. 95 locality in Texas from which the writer has seen a specimen of the species. West of the ninety-eighth degree of longitude specimens have been collected at the following points and elevations in the State of Texas: San Diego, 300 feet; Abilene, 1,700 feet; Barstow, 2,500 feet; Llano, 1,000 feet; San Angelo, 1,800 feet; San Antonio, 675 feet; Clarendon, 2,700 feet. The known Mexican localities _ where the species has been collected, with their elevations, are: San Pedro de la Colonia, Coahuila, 3,600 feet; Tlahualilo, Durango, 3,700 feet. FOOD PLANTS. Like most other plant-feeding Pentatomids whose habits are known, the conchuela has a wide range of food plants and shows a decided preference for fruits and seeds. In Texas and Mexico its principal food in uncultivated regions is the bean of the mesquite (Prosopis sp.) and the berry of a common wild solanum (Solanum eleagmfolium), known among the natives of Mexico as ‘‘trompillo.”’ Of these two the former seems to be preferred according to observa- tions in northern Mexico where the two food plants grow together on the arid plateaus. Records of other wild food plants of the species, with the observer and locality, are as follows: Spanish bayonet or bear grass (Yucca sp.), Barstow, Tex., J. C. Crawford; wild currant (Ribes sp.), San Antonio, Tex., W. E. Hinds and J. C. Crawford; sage, Clarendon, Tex., W. D. Pierce. Records of cultivated food plants, with the observer and locality, are as follows: Cotton, alfalfa, grapes, corn, chilli pepper, and tomato, Tlahualilo, Durango, Mexico, A. W. Morrill; peaches, Barstow, Tex., J. C. Crawford; cot- ton, grapes, Milo maize, sorghum, alfalfa, peas, tomato, Barstow, Tex., Crawford and Morrill. The fact that in 1905, at Barstow, Tex., the conchuela attacked several of these crops in sufficient numbers to cause considerable damage has been referred to under the subject of the history of the species. The range of food plants which has been recorded points to the likelihood that this insect may use as a food plant almost any of our cultivated grains, fruits, and vegetables which circumstances may place in the way. | DESCRIPTION. ADULTS. (Pine hie. i text fies 1.) This species belongs to the subgenus Chlorochra Stal, and in com- -mon with certain other members of this group exhibits a wide varia- tion in color. The general color is usually dull olivaceous, frequently either grayish, pinkish, purplish, or greenish, and occasionally black or brown. The punctures are black or dark gray. The species is most strikingly characterized by its general dark color, with the 26 PLANT-BUGS INJURIOUS TO COTTON BOLLS. lateral margins of the thorax above and below, the basal third to two-thirds of the costal margins of the wing corium, and the tip of the scutellum varying in color in different specimens from pale yellow to bright crimson. In a series of 63 specimens collected at random the range in length was found to be from 12 to 16.5 mm. While in this species there was one of either sex measuring 16.5 mm., the females in general are slightly larger than the males. Among 10 specimens of each sex collected at random in a cotton field, the average length was 15.1 mm. in the case of the females and 14.1 mm. in the case of the males, the former ranging from 14 to 16.5 mm., the latter from 13 to 14.5 mm. Fig. 1.—The conchuela (Pentatoma ligata): a, Adult bug; b, egg-mass on leaves; c, egg just before emergence of nymph; d, egg at an earlier stage of development; e, egg from side showing exit hole at the top; /, egg closed. a,b, enlarged; c-f, greatly enlarged. (Author’s illustration.) EGGS. (Text fie: i PV, fe. a) The writer has described the egg of this species in a previous report. From the examination of 25 eggs deposited by various females the dimensions may be stated as follows: The greatest diameter of individual eggs varies from 0.95 to 1.22 mm., rarely exceeds 1.1 mm., and averages about 0.98 mm.; the height varies from 1.2 to 1.45 mm. and averages about 1.28 mm. The egg is irregularly ovoid in form. When first deposited it is pale green but the chorion soon turns white except for certain areas which are translucent and grayish in color, turning to dark gray or brown as the embryo develops. Bul. 86, Bureau of Entomology. U. S. Dept. of Agriculture. PLATE V. FiG. 1.—EGG BATCH OF CONCHUELA (PENTATOMA LIGATA), SHOWING HATCHED AND UNHATCHED EGGS. ENLARGED 63 DIAMETERS. (AUTHOR’S ILLUSTRATION.) Fia@. 2.—EGa@ BATCH OF CONCHUELA FROM WHICH 32 PROCTOTRYPID PARASITES (TELENOMUS ASHMEADI) HAVE EMERGED ENLARGED 62 DIAMETERS. (AUTHOR’S |LLUSTRATION. ) This illustration shows three parasites, including male and female, ready to emerge; also an egg destroyed, probably by an ant. THE CONCHUELA. | 27 NYMPHS. (Figs. 2-6.) First instar.—In the first instar the head and thorax are deep brown. The abdomen is deep slate-gray with a middorsal series of shiny black spots, whitish at the marginal incisures between which iust inside the margin of each segment is a spot of deep brown. Speci- ‘mens in this stage vary in length from 1 to 1.75 mm. and in width from 1 to 1.5 mm. according to individual variation and age. Second instar.—The head and thorax of the nymphs in the second instar are shiny black, the thorax being margined with yellowish or orange-red. The abdomen above is dark viola- ceous, the venter paler. There is a series of Back spots on Fic. oases eee Nymph, first instar. the dorsum of the abdomen as_ Ai ae an ea aera in the first instar and a ventral series of black spots is sometimes present along middle one to each of the last four segments. The abdominal segments above and below have a yellowish or orange-red border, which narrows posteriorly. The length of second-instar nymphs varies from 1.6 to 2.5 mm., and the width from 1.3 to 2 mm. Third wstar—The nymphs in the third in- star are much like those of the second but are subject to greater vari- ation in color. There is more or less olivace- ous along the middle of the venter of the thorax. The abdomen usually Fic. 3.—The conchuela: Nymph, second instar. Enlarged 21 di- has a pale violaceous gi ie are ground color and dark violaceous spotting. The ventral series of spots is usually distinct, consisting of one spot on each of the segments from the fourth to the eighth, the anterior spot being the smallest. Frequently inside the reddish border on each segment from the second to the ninth is a ‘more or less thickened crescentic black mark. Corresponding 28 PLANT-BUGS INJURIOUS TO COTTON BOLLS. markings are sometimes present on the venter. The lines of the segments are usually dark in color. The length in this instar varies from 3.5 to 4 mm., and the width from 3 to 3.5 mm. Fourth vnstar.—The fourth instar is characterized by the first Fic. 4.—The conchuela: Nymph, third instar. ( Original.) ters. Enlarged 13 diame- - C@ous. external evidence of the developing wing- pads. The ventral side of the head, and sometimes the two basal segments of the beak, are more or less oliva- The black crescentic markings inside the margin of the abdominal segments are more distinct than before. Otherwise the color corresponds nearly with that of the third instar. The length of the fourth- instar nymph varies from 4.8 to 6.5 mm., and the width from 3.7 to 5 mm. Fifth instar—In the last or fifth nymphal instar the head and thorax are rarely uniformly black as in the two preceding instars but are more or less oliva- ceous, with black punc- tures. The venter of the thorax has usually an olivaceous but sometimes a pale pur- plish or rosaceous ground color, with black punctures and markings. ‘The basal segments of the legs are more or less oliva- ceous. The abdomen is colored as in the previous instars except that the ventral series Fic. 5.—The conchuela: Nymph, fourth instar. (Original. ) diameters. Enlarged 10 of spots along the mesal line is either absent or only faintly indicated. The length of the nymphs in the fifth stage varies from 9 to 11 mm., and the width from 6 to 8 mm. very. THE CONCHUELA. 29 LIFE HISTORY. METHODS OF STUDY. Studies in the life history of this and other species of plant-bugs were conducted in an improvised laboratory at Tlahualilo, Durango, Mexico, during July, 1905, and at the boll weevil laboratory at Dallas, Tex., after August 5, 1905. The insects were confined in lantern chimneys covered at the top with cheese cloth held in place by rubber bands, the number of adults to a cage ranging from one to five. The adults were provided daily with freshly picked green cotton bolls until about October 1, after which fresh bolls were . supplied every two days as long as any were available. Nymphs were fed upon fresh green cotton leaves or twigs, cotton bolls cut or broken in two. and imma- ture cotton seed from which the lint was first removed. Records were made atleast once each day, noting deaths, eggs de- posited, time of Fig. 6.—The conchuela: Nymph, fifth instar. Enlarged 6 diameters. examination, etc. (Original.) During thewriter’s occasional absences from the laboratory on field work these records were made by Mr. W. W. Yothers and Mr. A. C. Morgan. ADULTS. PERIOD BETWEEN MATURITY OF ADULTS AND BEGINNING OF EGG-LAYING. The data at hand on the length of time elapsing from the maturity of the adults to the beginning of oviposition are not sufficiently extensive to permit the drawing of conclusions. Apparently the specimens upon which the data are based were influenced by the lab- oratory conditions, for the period varied in length from 23 to 95 days and averaged 45 days in the case of the five specimens which were reared to maturity in the laboratory during July and August and which deposited one or more batches of eggs. Three females in addi- 30 PLANT-BUGS INJURIOUS TO COTTON BOLLS. tion to the foregoing lived_6, 34, and 125 days, respectively, but deposited no eggs. REPRODUCTION. Monthly and daily rate of oviposition and relation to temperature.— Including all the female specimens of Pentatoma ligata upon which observations were made, the average daily rate of egg production was 1.45. Omitting the month of November, during which no eggs were deposited, the rate was 1.8 per day, while up to October 1 the rate was 2.4 per day. The more important data on egg deposition are summarized in the following table: TaBLE I1V.—Rate of egg deposition of the conckuela. | Total | Average number of eggs deposited per Num- | num- insect per day. Lot. g ae Where collected. | ber of | ber of Pats females.) eggs de- | posited.) July.| Aug. | Sept.| Oct. | Nov. | Total. 1905. | eS a Wee July 6-10....| Tlahualilo, Mexico. 2h | 22,755: | 2.74.1 B05) (Os ata 0 1.92 i ee. fee Aug. 11-12. .| Barstow, Tex ...-.- 8 DOD cee ae oes 4.6 | Shale 0 2.5 (Cp Sa Seniesa hae dO: sacs bee dU A Ped U7 (kW Peete fas 6227 WeieG 0 5.4 1D ee ont uae OGi. Ase sees G07 )23}..c6b obs 210 Qa) 8). oa eae eee 0 0 0 a These insects were soft, indicating that they were newly matured. A study of the effect of temperature on egg production in the species here considered leads to the conclusion that the effective temperature as concerns egg-laying in the faunal region where these records were made, 1. e., Lower Austral, is a little less than 75° F. The effect of temperature changes upon egg production is well illus- trated bythe data given-in the following table relating to insects of lot A referred to in Table IV: | TasLe V.—Relation of temperature to egg-laying in the conchuela. | Average | ge Period. daily mean) gay depos- tempera- ited by 20 ae females. 1905. CUR: JURY: WA ate eet eee eee ok Se eee 82.6 67 July 10k oo ee oc oe ee 75.3 11 Thee OE OSes imac sek nas, eka 78.1 61 Sialy 26-20: eee asec see eee 80.8 66 THE CONCHUELA. 81 Egg-laying capacity—A summary of the laboratory records regarding egg-laying capacity is presented in the following table: TaBLeE VI.—£99-laying capacity of specimens of the conchuela collected in cotton fields. - Av oie ' Lean When | Number of! MUMmDer o EDEN: Lot. eggs depos- | eggs depos- collected.| females. ited per ited per female. female. In hibernation test December 1; all alive December 19; all dead March 8, 1906. ¢ Alive January 17, 1906, in hibernation cage; dead March 8, making 98+, but to keep on same basis as Other specimens the record was included only up to December 19, 1905. | THE CONCHUELA. 83 In order to show in a more graphic manner the vitality of the females collected at various times during the year, the data con- cerning that sex are arranged in the form presented below: TaBLE X.—Longevity of adult females of the conchuela collected in field. Number alive in sucessive months.a Number _ When collected. Where collected. of speci- Tess. July. | Aug. | Sept.| Oct. | Nov. | Dec. 1905. Jitby 6102525... - Tlahualilo, Durango, Mexico ..... 21 21 20 13 7 4 0 August 11-12... _-- SAUSbON LORE cars 2 Same o 5 ee Saat OVS. 8 4 1 1 0 September 12... .--|-...-. WO Se2 acne Messe dea= Sots ioe es Oma apes. Rete 14 6 0 0 . September 19.....- Glaren@on, (hex 38s sae 32 Slee 57 eee a Met pre 5 5 2 0 QMeteber IS... 222... IBATSLOW), HUOR Ui Go tees hececcces Osha sae ae er ale ce 10 10 d 10 ee we ett ciaed tn leas than. ive days after trip from. Barstow to Dallas, Dex: ¢ Not including 2 which died in less than five days after trip from Barstow to Dallas, Tex. d Hibernating alive December 19. All of the above records on the duration of adult life are incom- plete, as it was not definitely known in any case how long the insect had been in the adult stage when collected. Conditions at Tlahua- lilo indicate that the specimens collected at that point had been in the adult stage, on the average, about ten or twelve days. There were no means of judging on this point in the case of the specimens collected during August and September, but those collected on October 13 were still soft and specimens which died in transit contained no recognizable eggs; hence with little doubt this lot of specimens had matured within the week preceding their collection. Adults reared to.maturity vn the laboratory—As will be explained under the subject of the molting of nymphs, imperfect or crippled adults are frequently produced in the laboratory. From the ten apparently normal adults which reached maturity in confinement the most complete records on longevity were obtained. TaBLE XI.—Summary of records of longevity of adults of the conchuela which reached maturity in laboratory. Maximum Average Leama Where collected. When mature. longevity. ieagevie iM ; (Days. ) (Days. ) Ge =| 1905. SS sf © o ee 1 | Tlahualilo, Durango, Mexico.| July 21..............-- @49+ | @49+ |... /....2.2. “ag 2M Et | a | ee GOs ek a. Ee ae ee July 29 and August 4..|61438+ |........ 86+ |........ ohhh EE ee Barstow, Tex: s. 2). ie eS August 7 and 14....... Bree ee MOH ee te Dee cs a ee (OKC eee a a i ae August 15 and 16...... b 126+ 69 7i+ 53 a Specimens lost. b Used in hibernation test December 1, 1905; alive December 19, 1905. From the data given in the foregoing tables we are able to esti- mate approximately the length of adult life of the conchuela under 22348—Bull. 86—10——3 34 PLANT-BUGS INJURIOUS TO COTTON BOLLS. laboratory conditions. Fortunately the natural enemies of the insect _ and probably also its greater activity in the field materially lessen the average duration of adult life below that which was found to — obtain in the laboratory. A cage test in a cotton field failed to give positive evidence regarding normal longevity of the adults on account of the fact that the amount by which the insects’ lives were short- ened through their attempt to escape can not be estimated. Seven- teen specimens which became adult between July 25 and July 31 were confined in a wire cage placed over a cotton plant bearing a dozen bolls and many blooms and squares. The cage rested on — cheese cloth in order to facilitate the finding of dead bugs. On August 27 Mr. John Conduit, of Tlahualilo, noted that 10 live adults could be seen and no dead ones. On September 2 Mr. Robert Vaughan, of Tlahualilo, noted that there were 5 dead specimens, and on October 15 another dead specimen was observed. Live adults were noted as follows: September 10, 2; September 20, 1; October 9, 1; October 12, 2; October 15, 1; October 18, 1; October 20, 0; October 24, 0; October 31, 0. The number of adults noted on each date simply includes those which could be seen from out- side the cage. It is not impossible that some of the insects found an opportunity to escape, as of the 17 insects only 7 can be definitely accounted for.- The results show that 5 died in from 32 to 37 days, 1 in between 45 and 50 days, and 1 in between 78 and 83 days after reaching the adult stage. The sex of the specimens used in this cage ‘test was not recorded. Length of life when deprived of food.—Without food the life of adult conchuelas is very short in summer temperatures: On July 21, 28 adults—12 females and 16 males—taken on cotton plants at 11.30 a.m. were placed, at 12.30 p. m., without food, in a wire cage whose dimensions were 2 by 1 by 1 foot. The insects were very restless and flew almost continuously during daylight from one side to the other in the cage. In 33 hours from the time they were last fed only 7 of the 28 were alive and in 48 hours all were dead. In a second experiment 17 adults—8 females and 9 males—taken on cotton plants July 22 at 5 p. m. were placed, at 6 p. m., In a lantern globe loosely filled with soft, crumpled paper to prevent the insects from exhausting themselves by attempting to fly. Twenty- six hours after being deprived of food 9 of the 17 were dead and 41 hours after being deprived of food the last surviving specimen was noted as dying. The daily mean temperature at Tlahualilo at the time of the foregoing tests in the starvation of the conchuelas was between 75° and 80° F. On September 20, two specimens of this species were collected in western Texas and confined in separate pill boxes without food. These two specimens lived 5 and 6 days, respec- tively. The length of life without food is clearly dependent upon THE CONCHUELA. paises temperature conditions, as will be further discussed under the subject of hibernation. RELATION OF TEMPERATURE TO ACTIVITY OF ADULTS. Observations were made in October on some surviving specimens of the lots included in Table IX for the purpose of obtaining infor- mation on the effect of temperature on the feeding of these insects. The number of observations is too small to determine this point in more than a general way, and we are justified only in concluding that the degree of temperature at which feeding ceases is between 52° and 60° F. TaBLE XII.—Observations on relation of temperature to feeding of the conchuela. Number r Number Date of observation. Hour. | Ze™per- | of adults | Of adults Remarks. ature. | feeding not &* | feeding. 1905. ° oR Wlto Were ees. 8p.m 55-60 8 8 | Specimens in laboratory. OelanersdlOs se oes. ees. ease 2 5 7.15 p.m 66 7 12 Do. Ovioner sues sso. Fi 23206022 8.30 a. m 49 0 14 | Specimens out of doors. ID oe ee eee eee 8.15 p. m 52 0 19 | Specimens in laboratory. (OG NE Ter bse S Ae ae a 8.30 a. Mm 51 0 a19 Do. @ Including one with setz inserted in boll, but motionless and evidently not feeding. Plant-bugs in the laboratory have even been observed to die in this position. For comparison, observations were also made with a miscellaneous lot of Pentatomids, including specimens of Pentatoma sayr, Euschistus servus, Nezara hilaris, and Thyanta custator. 'These are summarized as follows: TABLE XIII1.—Observations on relation of temperature to feeding of miscellaneous Pentatomids. Number of | Number of Date of observation. Hour. sgt les = adults adults not : feeding. feeding. 1905. CL A ae MOetiahers tee dele prep eee ea eb Rae i ge ae 8p. m. 55-60 5 5 LOEWE IS 2A Ss Sa gS lean ae a ie ie Tt a ae Pee oi Melon pe aide 66 4 a Mecaver Ask so tee Se tae. eee eS ae ee 8.15 p. m. 52 0 7 EGGs. PERIOD OF INCUBATION. As is the case with all insect eggs, the developmental or incubation period of the eggs of the conchuela is influenced to a marked degree by slight variations in temperature. From the entire lot of egg- batches deposited in the laboratory, numbering over 160, 26 have been selected for a study of the relation of temperature to incubation period, owing to the comparative completeness of the records. The \ 36 PLANT-BUGS INJURIOUS TO COTTON BOLLS. ey number of intervening calendar days has been taken as the basis and the additional periods approximated by a plan which has been fol- lowed throughout and which is believed to have produced very nearly correct averages. To the number of intervening calendar days has been added the known additional hours and one-half the hours between observations during which egg-laying or hatching might have occurred. In many cases the exact time of the egg-deposition or of hatching was noted, consequently lessening the chances for error. For example, a female was observed in the act of depositing an egg-batch at 4 p. m., July 16. This batch had hatched when the record was taken at 3 p. m. on July 23. The number of intervening calendar days in this case was six. The known additional period is 8 hours, 4 p. m., July 16, to 12 midnight. The period preceding the time the eggs were first noted as having hatched, during which no— observations were made, was 23 hours, one-half of which is added to the known period of 8 hours, making practically five-sixths of a day. This added to the intervening calendar days gives 6% days as the approximate incubation period. TABLE XIV.—Relation of temperature to period of incubation of eggs of the conchuela. | Range. Average. Num- Num- ‘4 : = OEE: — ae —— dantie = DpIOAT daily ace rite: Approxi- batches.| ©885- | calen- ae temperature | tem- | mate incuba- dar Seal for interven- | pera- | tion period. days. Pp 4 ing days. | ture. 1905. Tlahualilo, Du- Days. = Oe °F. | Days.| Hours. rango, Mexico.| July 14-23......- 3 99 | 6 to 6 | 74 to 62 | 75.4 to 76.1 | 75.8 6 19 DO es eee July 22-30...-..- 5 234 | 5 to 4 | 62; to 5k | 79.1 to 79.5 | 79.4 5 9 Dallas, Tex..... Aug. 6-Sept. 15.. 11 350 | 3 to 2 | 4% to 34 | 80.1 to 86 82.8 3 15 Woxwtoo-e Sept. 16-Oct. 5... 7 313 |6 to 4) 7 to 5S | 73.7 to 75 74.3 5 23 Summary with averages.....-. July 14-Oct. 5. --| 26 996 | 2 to 6 | 34 to 74 | 73.7 to 86 78 5 8 From the last three columns of the above table can be computed the average effect of 1° of temperature on the duration of the incubation period within the limits noted. TaBLE XV.—LF ffect of 1° of temperature on incubation period of eggs of the conchuela. Range, average ee Increase or decrease in incu- Place. daily mean popcsenie d bation period correspond- temperature. by range. ing to 1° of temperature. Tlahualilo, Durango, Mexico..........-.....-. | 75.8 to 79.4 | 3.6 | 0.39 days or 9 hrs. 30 min. Wallace Mem ass. coe 2s ee ene ee ee eee | 74.3 to 82.8 8.3 | .27 days or 6 hrs. 30 min. | The average of the Tlahualilo and Dallas records shows that between the limits of 74.3° and 82.8° the average increase or decrease in the incubation period corresponding to a single degree of temperature is THE CONCHUELA. 37 estimated at 7 hours and 55 minutes. It is a notable coincidence that in the case of the eggs of the spined soldier-bug (Podisus macu- liventris Say) the author found in Massachusetts that with an aver- age daily mean temperature ranging between 62° and 72°, 1° of tem- perature corresponded with approximately 7 hours and 40 minutes.* An instance of a much more prolonged incubation period was not included in the foregoing table but was reserved for separate discus- sion, as it is evidently a case of intermittently arrested development, due to low temperatures. The egg batch in question numbered 28 eggs and was deposited on October 17; 13 hatched on November 3. The average daily mean temperature® during the 16 days of incuba- tion was 65.7° F. The average daily maximum for this period was 72.3° F. and the average daily minimum was 59° F. To the author it seems plain that the 16-day period can only be explained by | the supposition that development of the eggs was arrested from time to time by the low temperatures. Here again a comparison with the records obtained from the eggs of the other species of the Pentatomid mentioned in the preceding paragraph is instructive as showing the adaptation of the physiological processes of the two species to climatic conditions. The eggs of the spined soldier-bug at Amherst, Mass., with practically the same average daily mean temperature (65.5° F.) hatched in 84 days, or after a period one-half as long as in the case of the eggs of the conchuela. PROPORTION HATCHING IN THE LABORATORY. In many cases no note was made as to whether or not eggs hatched, but the records of nearly a thousand eggs will suffice to give fairly accurate knowledge on the subject. The eggs selected were deposited during July and August by conchuelas collected in the cotton fields at Tlahualilo and abnormal conditions were eliminated, as will be ex- plained. The total number of eggs was 942, and of these 68, or 7.2 per cent, failed to hatch. -Eggs of the conchuela deposited in the field seldom fail to hatch if not destroyed by parasites or predaceous enemies. The number of unparasitized egg-batches collected in the field is too small to permit the drawing of conclusions concerning the proportion that hatch, and for information on this point laboratory data must be used. If, however, we omit records of eggs from infertile females and of certain abnormal eggs, mechanically pre- vented from hatching, there is no reason to expect any appreciable difference in the proportion of eggs hatching under laboratory con- ditions and those hatching under normal field conditions. Infertile eggs have never been collected in the field nor has any egg-laying 2Bul. 60, Bur. Ent., U. 8. Dept. Agr., p. 158, 1906. > Records based on a recording thermometer in the room with the eggs. 38 PLANT-BUGS INJURIOUS TO COTTON BOLLS. female brought from the field into the laboratory proved unfertilized; hence this factor should be eliminated from the laboratory records in order to make them comparable with actual field conditions. As an illustration of the mechanical prevention of hatching referred to, a conchuela in one instance deposited eggs in two layers, the nymphs in the lower layer of eggs, numbering 20, being of course unable to escape from the shells. This manner of depositing the eges was evidently due either to interference by other specimens in the cage or to a lack of sufficient leaf-area, both of which conditions are abnormal. Occasionally eggs are deposited, both in the labora- tory and in the field, wrong side up with relation to other eggs of the batch. This also usually results in mechanical prevention of hatching and accounts for the failure to hatch of somewhat less than 1 per cent of the 942 eggs referred to above. Other eggs may fail to hatch owing to the exit hole at the top being abnormally small, as the author has observed to occur in two instances with eggs of the harle- quin cabbage bug (Murgantia histrionca Hahn). The extent of this abnormal condition may not be noticeable, yet sufficient to prevent emergence of the nymph. Still other eggs may be abnormal in the respect that the lid which must be raised to permit the escape of the nymph is too solidly attached to the neck of the egg in proportion to the strength of the insect. EFFECT OF LOW TEMPERATURE ON VITALITY. An experiment was made to determine the extent to which de- velopment of eggs might be retarded or otherwise affected by low temperature. In this experiment 12 egg-batches comprising 288 eges were used, all of which were deposited between August 27 and September 16 by 8 different females. Each batch of eggs was placed in an ice box within 24 hours after being deposited and kept there until November 2, with the temperature almost invariable and averaging 49° F. Upon examination it was found that the eggs had been entirely destroyed, being shriveled so that there could be no doubt of their condition. It would seem, therefore, that such long- continued low temperatures are fatal to the conchuela in the egg-stage. HATCHING. As the eggshell is nontransparent, the developing nymph is invisible up to the time of hatching. The stout spine on the egg-burster is directed at the suture between the lid and the neck of the egg at a point opposite the hinge. By pressure from below a split is made along the suture and the pale pinkish head of the nymph surmounted by the egg-burster appears beneath the partially opened lid. The integument of the insect being soft, the emergence is by slow, scarcely perceptible peristaltic movements, the egg-burster slipping over the a THE CONCHUELA. 39 head and along the venter as the emergence progresses. The position of the nymph in the egg is with the dorsum toward the hinge of the lid. The antenne and legs are closely appressed to the body and extended directly backward. Movement of the antenne and legs begins as soon as they are free from the egg and emergence is not completed until the legs are sufficiently strong to enable the insect to cling to the egg-batch. Individual nymphs have been observed to emerge in from 12 to 15 minutes after the lid is first raised. Emer- gence of nymphs from a batch of eges usually extends over a period of less than 14 hours, but activities in this line asin others are largely under the iibace af temperature. A record on October 10 shows a difference of 2 hours and 15 minutes between the appearance of the first nymphs and last nymphs to emerge from a batch of 13 eggs. NYMPHS. DURATION OF NYMPHAL STAGES. Under normal summer temperatures.—In spite of the most careful attention one can reasonably give, the death rate of Pentatomid nymphs under observation in the laboratory is very high. In no case were nymphs of the conchuela reared to maturity in the labora- tory, but the duration of the various stages was determined by more than 35 individual records. The prevailing temperature conditions seem to control the duration of the nymphal stages of these and other Pentatomids, while a lack of food supply seems to result only in either a stunted growth or death from starvation. During the months of July and August, 1905, at Tlahualilo, Durango, Mexico, and Dallas, Tex., respectively, the data summarized in the following table were obtained, being based on from 5 to 35 specimens in each instar. TaBLE XVI.—Observations on duration of nymphal stages of the conchuela. Average | Minimum | Maximum s Stage. duration. | duration. | duration. Days. Days. Days. PERRET LEIS cise, Senet eee pa Ve et we ee i Oe 4.5 4 5 Ee OTE MEINS VEL ee aya Ne eh ie ee reese Pe Nt a St! 6 5 7 USUBUTRO LTS UA ELS Bs Ss Boe 2 a ie ie ee Oi hte 8 6 10 LE CLOT ELD TBST SRS Ste Ea ale ad a il A Un Ope Oe A 8 5 12 SEER clTMER SHI Spee eye eee ee ee ee, Ti A St Deel Dn ace 1 7 17 ANSELTGIS italy o) AE) GS TORS) Bes enantio ie ne Re T e aee in eeeee 38. 5 27 51 It is very unlikely that the maximum duration of each stage given ‘above would ever be equaled by a single specimen passing through the successive stages, even in the laboratory during the summer months. It is, moreover, probable that under out-of-door temperature condi- tions the average duration of all nymphal instars taken together is a few days less than the average obtained by the laboratory observations. aged ae Bs oe 2 i 40 PLANT-BUGS INJURIOUS TO COTTON BOLLS. This would seem to be the natural result of the insects being fre- quently exposed to direct sunlight. The average daily mean tem- perature during July at Tlahualilo was 81.5° F., and during August at Dallas was 82.8° F’., the daily mean for the 2 months averaging 82.1° F’. There is considerable variation independent of. tempera- ture. This is shown by specimens reared from the same egg-batch and kept in the same cage, having in every respect equally favorable opportunities for development. The range in duration of the stages becomes greater with each succeeding instar, which fact is well brought out by Table XVI. Cold as a factor in retarding development.—At an average daily mean temperature of 69.4° F., the minimum length of the second instar among three specimens of the conchuela was 19 days, the period being from September 26 to October 15. In Table XVI is included a record of 7 days as the duration of this instar in one specimen. ‘This repre- sented the minimum length of the second instar among more than 10 specimens of the same brood. The period extended from July 20 to July 27, the average daily mean temperature being 77.9° F. A comparison of these two records plainly shows the effect of tem- perature on the duration of nymphal stages. Still greater retarda- tion was exhibited by a lot of 31 fifth-instar nymphs of the conchuela, although the records are not as exact as those given, owing to the fact that the specimens were collected in the field and the entire length of the stage is consequently unknown. The specimens referred to were collected at Barstow, Tex., on October 13, and taken to the laboratory at Dallas, where they were confined in a wire breeding- cage out of doors, and supplied with fresh cotton bolls up to about the middle of November. From among these nymphs adults appeared on the following dates: October 17, 2; October 18, 1; October 19, 2; October 26, 3; November 3, 1. Nymphs were recorded as dead on the following dates: October 10, 5; October 14, 2; October 16, 1; October 26, 1. On December 19, 2 nymphs were still alive, although feeble and barely able to crawl, owing to lack of food. The average mean temperature at Dallas from October 15 to December 19 was 53.7° F., the October average being 62.9° F., November, 57.1° F., and up to December 19, 41° F. LENGTH OF LIFE WITHOUT FOOD. Like the adults, the nymphs of the conchuela, when deprived of food during the summer months, are short-lived. Nymphs in the first instar have been recorded as surviving as long as 5 days without food, which period is the longest ever noted under natural tempera- ture conditions in any instance during the months of July, August, and September. On August 11, 46 nymphs hatched from a batch of egos and all but 3 of these were dead from starvation on August 14, THE CONCHUELA. 41 none surviving after the fourth day. There seems to be little or no difference in the ability of nymphs in later instars to withstand starva- tion, so far as observed in all cases with summer temperatures, death taking place in from 2 to 4 days. Data in connection with the retard- ing influence of cold, given in the preceding paragraph, illustrate the effect of low temperature on the length of life without food of nymphs ‘in the fifth instar. In an ice box with an average temperature of 48.6° F., the life of a nymph of the first instar has been prolonged to nearly 40 days without food. In the brood of 24 nymphs to which this specimen belonged, all were alive on the seventeenth day after being placed in the ice box; 18 alive on the twenty-third day; 10 alive on the twenty-ninth day; and only 1 alive on the thirty-seventh day. A third-instar nymph, robust, and apparently well fed previously, lived only 8 days in the ice box without food, the temperature as before averaging 48.6° F. MOLTING. As the time for molting approaches, a nymph becomes less active, ceases to feed, and shows a tendency to seclude itself where it will be less liable to interference by other individuals of the brood. A twig — or other suitable object is tightly clasped, and the insect by pressure, exerted perhaps by means of air drawn into the trachea, splits the integument of the dorsum along the mesal line of the thorax, and in a line on each side of the head extending from the inner margin of the eye backward to the prothorax. The insect becomes freed from its old skin usually in the course of twenty or thirty minutes, although in one observation a conchuela in molting its fifth-instar skin required slightly over an hour. The insect as it emerges is pale pink and very soft, but gradually attains its normal color during the course of an hour. Adults remain soft to the touch for several days after molting. The molted skin which originally covered the abdomen shrivels, and, as is also the case with the integument which covered the thorax and head, only the black markings remain. HABITS. NYMPHS. FEEDING AND GREGARIOUSNESS. For several hours after hatching, the young nymphs of the con- chuela remain closely clustered either on or near by the egg-batch. If there are any unhatched eggs in the batch, the nymphs after a few hours’ quiescence begin to feed on them, although it is probable that if such eggs contain nymphs they are dead or unable to hatch. Frequently enough food is contained in unhatched eggs of a batch to enable several nymphs to molt for the first time. For the most 49 PLANT-BUGS INJURIOUS TO COTTON BOLLS. part the nymphs are dependent on the juices of plants for food although eggs of their own and other species of insects are fed upon with relish wherever accident places them in their way. Except for this habit of feeding on insect eggs, the writer has never observed nymphs of the conchuela to attack living insects. In one instance, however, a nymph in the fifth instar exhibited a decided preference for ani- mal food over vegetable. This nymph was in a cage in the labora- tory with specimens of other species of Pentatomids, including a nymph in the fifth instar of Podisus lineatus H. Schf. This last- mentioned specimen died, but was not removed from the cage, and 24 hours later the nymph of the conchuela was observed feeding on the dead insect. As there was a fresh cotton boll in the cage, feeding on the dead inse:t was clearly a matter of preference. The habits of nymphs on the cotton plant are much like those of the adults, except that the nymphs are less conspicuous, frequently being entirely hidden by the bracts of the bolls. They have a well- marked gregarious tendency, especially in the first three stages, dur- ing which all the surviving nymphs of a brood are usually found on the same boll. In a field at Tlahualilo, nymphs of the fifth instar occurred in unusual abundance in a field of cotton averaging 5 or 6 bolls over 1 inch in diameter per plant. The nymphs reached the plants by crawling, and at the time of examination while less than one-fourth of the total number of bolls were infested, as a rule, each infested boll had several nymphs clustered upon it. As many as 17 fifth-instar nymphs were counted on a single boll, while frequently from 5 to 15 nymphs were found on a single boll, with the plant otherwise free from the pest. DISTANCE CAPABLE OF TRAVELING FOR FOOD. The distance which nymphs of the conchuela are capable of travel- ing for food proved to be a matter of considerable importance at Tlahualilo in 1905, owing to an invasion by nymphs of vineyards, gardens, and cotton fields adjoining an alfalfa field where the insects were breeding in enormous numbers. The cutting of the alfalfa removed the food supply of the insects, thereby causing a migration in search of food.* The adults distributed themselves by flight, but the migration of the nymphs was limited by their capabilities for crawling. Few of the nymphs in the first 3 instars got beyond a4 Migrations of this kind have not been previously unknown among the Penta- tomide. Prof. D. A. Saunders in reporting an unusual outbreak of Uhler’s green plant-bug (Pentatoma uhleri?) in South Dakota says regarding this point: ‘“‘By the middle of June the bugs, being now about half-erown and their wings beginning to appear, began to migrate in great droves ‘on foot’ toward the cultivated fields. Mr. Senn estimates that they would make about one-half mile in a little less thana day across cultivated fields * * *.”’ (Bul. 57, 8. Dak. Exp. Sta., p. 39, Feb., 1898.) THE CONCHUELA. 43 the limits of the alfalfa field. The fourth-instar nymphs were found in abundance on fence posts, tree trunks, cotton plants, and weeds within 10 yards of the alfalfa field where they originated, and were scarce from 10 to 20 yards from this field. Nymphs in the fifth instar invaded a cotton field up to about 30 yards, in numbers estimated to average between ten and fifteen per plant; from 30 to 40 yards, between five and ten per plant; and from 40 to 60 yards, between two and five per plant. Few, if any, attained a distance of more than 60 yards from the point of origin. In these estimates due allowance has been made for the nymphs which occurred in the field before the beginning of the migration. These records do not show the maximum distance which the nymphs are capable of crawling, for the new food supply immediately adjoined the field of original infestation. It is certain, however, that this distance is over 60 yards. ADULTS. FERTILIZATION. Laboratory observations show that males of the conchuela are polygamous and females polyandric. During copulation in the cot- ton fields, both insects are usually engaged in feeding on a boll or other part of the plant. No attempt has been made to ascertain how long a pair of the insects remain in coitu, but in 2 instances a note was made of more than one-half hour or more than 2 hours, respec- tively. With other species of Pentatomid bugs, pairs have been observed in coition for.a period of several hours at a time. EGG LAYING. Place of deposition.—Egegs are deposited in batches or clusters wherever the female happens to be feeding or resting. On cotton they have been found on both upper and lower surfaces of the leaf, though more commonly on the latter, also on bracts of bolls and on stems. In a cotton field at Llano, Tex., in September, 1905, a female con- chuela was observed depositing a batch of eggs on lint in an open boli. On grape, 11 batches of eggs collected on July 12 were deposited as follows: 8 on underside of the leaves, 1 on the upper surface of the leaf, and 2 on the tendrils. Of 9 egg-batches collected on July 17, 4 were on the underside and 3 on the upper surface of alfalfa leaves and 5 on the underside of a solanaceous weed, the ‘‘trompillo”’ of the natives of Mexico. At Barstow, Tex., eggs of the conchuela with eges of another Pentatomid which will be referred to later—Penta- toma say Stal—were frequently found on the seed-clusters of alfalfa, a favorite fecding place. In captivity the females of the conchuela, as well as other cotton-feeding Pentatomids, deposit eggs usually on the cotton bolls supplied for food, but occasionally on paper at the bottom of the cage and on the cheese-cloth cover at the top. ~ 4a PLANT-BUGS INJURIOUS TO COTTON BOLLS. Number of eggs per batch.—The conchuela, in common with other members of the family Pentatomide, deposits eggs with considerable regularity in parallel rows, each egg except those in the outside rows being in contact with 6 others. The frequency with which eggs are deposited in multiples of 14 is strongly marked. A total number of 172 egg-batches of this species was deposited in the laboratory during these investigations. The total number of eggs in these batches was 4,900, or 28.4 eggs per batch. The number of eggs most frequentiy noted in single batches was 28, and the number ranking next in frequency was 42. The maximum number of eggs deposited in a single batch was 79. Rate of deposition of indwidual eggs.—The intervals between the deposition of individual eggs in a batch, with midsummer tempera- ture, varies from one minute to one and three-quarters minutes according to records made in the case of 2 females under observation while depositing eggs. The first of these specimens deposited 13 egos in twenty minutes, 4 of which were deposited with one-and-one- half-minute intervals. The second specimen deposited 15 eggs in as many minutes. FEEDING. Part of plants preferred.—The conchuela shows a marked preference for the juices of the seeds and fruits of its food plants. In a report of preliminary investigations of this insect the writer recorded an observation regarding this preference. As no specific observation on this point has been made, it may be repeated that of 57 adults feeding on cotton plants, 43 were on bolls, 4 on leaves, and 10 onstems. The proportion feeding on bollsin this observation is less than ordinarily, as is incidentally shown by data given in another paragraph relating to proportion of time adults spent in feeding. The immature seed are the objective point of the insect’s attack, as has been stated in de- scribing the nature of the plant-bug injury. Rapidly growing bolls of medium size are preferred to large, nearly mature bolls, the lint of which offers serious resistance to the entrance of the threadlike mouth setz. In connection with this preference bolls on the lower branches of the cotton plant are less subject to attack than are those growing on branches higher up. Conspicuous position when feeding.—The conchuela is by far the most conspicuous of the Pentatomids destructive to cotton bolls which are discussed in this bulletin. This is as much so on account . i in of its selection of a feeding place as on account of its size and striking ~ color. This characteristic is an important factor under some condi- tions in the control of the pest in cotton fields, as will be explained in discussing remedial measures. The author’s outline of field work necessitated the examination of many thousand cotton plants for the purpose of counting the insects which were found on them. From THE CONCHUELA. 45 this experience it is certain that in the cotton fields in clear summer weather fully 90 per cent of the conchuelas are visible to the observer from a standing posture and without moving any part of the plant. It was a rare occurrence, when making records of the kind indicated, that any additional specimens of these insects were found by using the hands to open up the plant. Only a few instances have been observed where the adult conchuela has been entirely or almost en- tirely hidden by the bracts of the cotton boll on which it was feeding. When feeding on a boll these insects generally occupy a position on the upper half. When resting, during bright sunlight, they are com- monly observed in a conspicuous position on the cotton boll or on the upper surface of the leaves. The resting in the sun is usually observed during the forenoon. Proportion of time adults spend in feeding.—In the determination of the amount of damage an individual conchuela is capable of inflicting in a cotton field it is important to know what part of its time it is engaged in feeding on cotton bolls. Observations were conducted both in the laboratory and in the field, and the results are summarized in the following tables: TaBLE XVII.—Feeding records on the conchuela in the field, Tlahualilo, Durango, Mexico, July 22, 1905. Number of con- Number of con- . Number of ob- . chuelas crawl- | Per cent feed- Hours of observation. servations. chuplas Jeeding ing or resting | ing on bolls. ; on plants. so Lees Long 1 1172401 (0 ee a 251 142 109 56 USCS TRO GD cs 66 51 15 77 Summary for day .=:--- 22.22... 2- 317 193 124 66 TaBLE XVIII.—Laboratory feeding records on the conchuela, Lot A,@ Series I, Tla- hualilo, Durango, Mexico, July 20-22, 1905. Number of con-| Number of con- Hours of observation. Rhea chuelas feeding| chuelas not eee Serve ; on bolls. feeding. ene: (oS UNE ye TOC OMe es U)icz eg 0 ee ee 69 50 19 72.4 ONG. TIE Os a 0 0 a i ae 46 46 25 45.6 TL TDN ICTS ACE) 0) 0 ee 115 57 58 49.5 EO pata GOD. We a 5262 cees bol os 69 48 21 69.8 ‘er TOPLEE aD I 0) Ria TR ea ae Te 69 62 fi 89.8 TaBLE XIX.—Laboratory feeding records on the conchuela, Lot A, Series II, Dallas, Tex., September 4-8, 1905. Number of con-| Number of con- Hours of observation. ae ae chuelas feeding| chuelas not eee : on bolls. feeding. 8: Pen POR Ein. ee ye Ue ote Fae ts 47 8 37 17 2 (Do TADS ACO) CN 0 «a ce res ae eee 24 9 15 37.5 geet Wp: Mm... .. 5/2 e ee kc eee 24 15 9 62.5 a Collected in cotton fields in Tlahualilo between July 6 and 10, e a“ z - Fe ~~ 46 ‘ PLANT-BUGS INJURIOUS TO COTTON BOLLS. TaBLE XX.—Summary of laboratory feeding records on the conchuela, Lot A. : Per cent feed- | Per cent feed- Per cent feed- — Place. ome ingin daylight.| ing at night. hee and Tlahualilo, Durango, Mexico.........-- July 20-22,1905 59.4 89.8 74. Dallas Pexs Sc 72n2: hepa ie sae see z Sept. 4-8, 1905 27.2 62:5) ee 44 A comparison of Tables XVII and XVIII shows a close corre- spondence between the laboratory and field observations on the amount of time the adults spend in feeding during daylight. The fact that in the field the conchuela feeds almost constantly after sun- — set has already been recorded. We may safely assume that the adults feed for fully as large a percentage of the nighttime in the field as in the laboratory. Considering, therefore, that 90 per cent of the night (Table XVIII), and 66 per cent of the day, is spent in feeding, the percentage of the calendar day spent in feeding at the times and places of these observations was approximately 78. - Table XX shows a difference between the same lot of insects which is probably attributable to the difference in age of the speci- mens. Difference in temperature could have had no appreciable effect as it was slight, the average daily mean at Tlahualilo on the days of the observations being 76° F’. and at Dallas 79° F. Method of attack.—For locating the position for piercing the carpel of a cotton boll the conchuela makes use of its antenne and tip of ‘the rostrum. As in other Heteroptera, the rostrum is used only as a guide for the threadlike sete and is never forced into the object upon which the insect may feed. As the setz sink into the boll the rostrum bends at the joint between the first and second segments, being directed backward. The setz at the same time are freed from the rostral groove of the basal two segments, and as these two seg- ments fold together, this allows a greater depth of penetration. Next, the apical or fourth segment is bent or folded back leaving the setz in the rostral groove only at the angle between the third and fourth segments. In this position the rostrum forms a letter ‘‘Z,” the upper angle representing the joint between the second and third and the lower angle the joint between the third and fourth segments. Feeding may be continued with the rostrum in this position or the rostrum may be freed entirely from the setz and directed straight back along the middle of the venter in the usual position it occupies when the insect is resting or crawling. The insect may therefore use practically the entire length of the sete to penetrate through the carpel and the developing lint to the cotton seed. This length is about one-fourth of an inch. When feeding, the bug alternately aBul. 54, Bur. Ent., U. 8. Dept. Agr., p. 26, 1905. THE CONCHUELA. 47 raises and lowers its head. After withdrawing the setz from the boll, a downward stroke of one of the fore tibie places them in the rostral groove, each tibia for this object being provided with a short spine located on its inner side slightly beyond the middle. Miscellaneous observations on feeding habits.—Twenty-six observa- tions gave 20 minutes as the average time the adults fed through one puncture in a cotton boll. The maximum length of time in these observations was 1 hour and 30 minutes. In his report of prelimi- nary investigations* on the conchuela the author presented his observations on the length of time adults remain on a single boll and on a single plant as follows: ‘‘One adult under observation in the field visited 4 bolls, 2 on each of 2 plants in 2 days, and remained for over 36 hours on the last of the 4 bolls. Another adult bug remained on the same boll for 2? days. Three remained on the same boll for over 30 hours and 3 others were found on the same plant 30 hours after they were first recorded. In none of these cases was it known how long the insects had been on these plants previous to their first being noted.’’ Abnormal predaceous and cannibalistic habits —Starving adult con- chuelas confined with live caterpillars of the bollworm (Heliothis obsoleta Fab.) and the cotton boll cutworm (Prodema ormthogalli Guen.) failed to exhibit any indication of carnivorous habits. Dead or dying insects, however, are not always refused and are sometimes fed upon by adults as well as by nymphs in preference to cotton bolls. (See feeding habits of nymphs, pp. 41-42.) Ona few occasions where 2 or more adults have been confined together in breeding cages, dead or dying specimens have been fed upon by the survivors of the lot. Ail evidence at hand goes to show that in the field the adult conchuelas are entirely phytophagous. GREGARIOUSNESS. The gregarious habit exhibited by the conchuela, like its habit of occupying a conspicuous position on the plant, is of considerable importance in its control. The author has previously noted ° this striking feature, basing the records on observations made at a season of the year when these insects were comparatively scarce. Between August 31 and September 6, 1904, in a selected section of the cotton fields at Tlahualilo, 34 adults were collected on 16 plants, although the insects were so few that but 5 or 6 plants out of 100 were found to be infested. In July, 1905, 2 other species of Pentatomids _ (Pentatoma sayz Stal and Thyanta perditor Fab.) were found associated with the corchuela and occurring in moderate abundance on the aBul. 54, Bur. Ent., U. S. Dept. Agr., p. 26,1905. ® Loc. cit., pp. 26-27. 48 PLANT-BUGS INJURIOUS TO COTTON BOLLS. cotton plants. Field observations showed that whatever the nature of the attraction which is the basis of the occurrence, it is operative between the different species of Pentatomids as well as “betaeea individuals of the same species. As a result of this gregarious tendency it was found that of 467 cotton plants examined on July 15, 1905, in one of the most heavily infested sections of the plantation ait Tlahualilo, the infested plants, or those plants upon which there was at least 1 bug, numbered 91 and averaged about 2 bugs per plant. There were therefore about five times as many of the insects upon the infested plants as upon the average of the plants examined. A further concentration of these bugs was observed on the individual bolls. Of 100 bolls upon which one or more of the bugs was feeding 52 were found to have from 2 to 5 bugs each and 48 only 1 bug each. In all, there were 175 bugs feeding on the 100 bolls. FLIGHT. In September, 1904, conchuelas in the field showed themselves capable of only short flights, about 25 feet being the maximum dis- tance attained by any one effort observed. In July of the following year observations showed these insects to be strong fliers. Gentle winds have little effect on the flight of the insects, as they seem to fly as often against as with the wind. Many of the insects have been observed to fly as far as the eye could follow. In one instance when lost to view the specimen was about 50 feet above the ground and eradually rising higher; in another case a specimen disappeared from view without rising higher than 15 or 20 feet. The numbers of the insects in any given locality are subject to rapid changes owing to their flying propensities, but extensive migrations are always traceable to the need for a fresh food supply. SEASONAL HISTORY. INCREASE AND DECREASE IN NUMBERS DURING THE SEASON. Previous to the season of 1903, as far as can be learned, the con- chuelas attracted no particular attention as cotton pests in the Laguna district of Mexico. For the information here presented concerning the seasonal history of these insects in 1903 and 1904 the author is indebted to Mr. John Conduit, resident manager of the Tlahualilo cotton plantations, who, owing to the immense tract of cotton grown under his supervision, gives particular attention to cotton pests, and in addition to personal examinations in the fields directs the ‘‘bosses”’ of the various parts of the estate to send in to the office specimens of insects taken on the cotton plants, with information concerning their abundance. The bosses in their turn make examinations and send dozens of laborers into, the various THE CONCHUELA. . 49 subdivisions of the estate to search for any particular insect concern- ing which information may be desired at headquarters. This sys- tem made it possible to obtain accurate information concerning the abundance of the Pentatomid bugs here considered. In 1903 the conchuelas were abundant only during the month of July and reached a maximum in numbers about July 20. Their first appearance was in the outlying districts, next to the mesquite, but they soon spread all over the cotton plantation, although they were more abundant in certain parts than in others. The insects disappeared early in August and did not reappear in noticeable abundance during the season, although the cotton plants remained - green until October 17, when the first. frost was recorded. Although a close watch for the insect was maintained during the late spring and early summer of 1904, the first specimen was not taken in the field until July 6. During the following seven days a rapid increase in its numbers was noted, and on July 17 it was observed that a marked decrease had occurred. Nowhere on the plantation were the insects as abundant as in July of the previous year, nor were they so generally distributed. On August 31 a personal examination in the cotton fields by the author showed the insects to be very scarce, although in certain sections of the plantation the open cotton bolls with stained and . ruined lint gave unmistakable evidence of their greater abundance a few weeks earlier in the season. In July, 1905, a detailed numerical study was made, which verifies Mr. Conduit’s general observations for the two previous seasons. While the subject of natural enemies is discussed under a separate heading, it is necessary to mention here that the abundance of the conchuela during the season is principally dependent upon the efficiency of its parasitic and predaceous enemies. Egg-laying by the average individual is distributed over such a long period of time that it can hardly be said that the conchuelas naturally appear in broods. However, practically the same effect may be produced locally to a greater or less extent by the action of natural enemies. During the first two weeks of July adults and nymphs in all stages were found in abundance on mesquite in the uncultivated lands surrounding the Tlahualilo Cotton Plantation. The gradual ripen- ing and drying of the beans was evidently causing a migration of the adults in search of food, many finding their way into the cotton fields. Ege-parasitism was acting as a practically complete check on further multiplication in the mesquite. In their search for food the first migrants from the mesquite settled in large numbers in sec- tions of the plantation upon which zoca or seppa (stubble) cotton was growing, and later the migrants showed a preference for the planted 22348—Bull. 86—10——4 50 PLANT-BUGS INJURIOUS TO COTTON BOLLS. cotton when the bolls became more numerous and large enough to be attractive to them. | - The most thorough study of the changes in the numerical status of the conchuelas during July, 1905, was made in a tabla comprising about 120 acres and known as ‘“‘Ceceda A 14” (fig.7). The cotton in this tabla was zoca or seppa, and during the first half of July repre- HL ‘Wel 0 WHI VAL bod PYPOU A WY I Fic. 7.—Diagram of a portion of the Tlahualilo Cotton Estates. The shaded tablas are the principal ones referred to in the text. (Original.) sented conditions more attractive to the insects than did any equal area of planta (planted) cotton. Five examinations were made during July near the west end of this tabla, beginning with a row about 15 or 20 yards from the end and examining across the tabla, changing to next row east, every 10 plants. The results of this examination are summarized in the following table: TaBLE X XI.— Variation in abundance of Pentatomids during July, 1905, at Tlahualilo, Durango, Mexico. Average. ..- Number of | Number of Adults per 100 plants. Totaladult | Number of , 5 infested Pentato- | nymphs P. eS yee plants mids per | ligata per P : in 100 P. ligata. P. sayi. | Thyantasp.| 100 plants. | 100 plants.a la Se ae 100 19 52 0 0 52 0 i eae 99 30 52 3 2 57 13 14 7AM Rs Se 98 31 59 4 0 63 24 DD arene ciety ae 103 12 33 | 0 | 33 0 DOSE om pee 96 ii alyé 0 Orne] 17 y eee 1 Pptall es! e 493 | 99 213 7 2 222 6 .6 ; 42.6 ity 45 44.2 14 [rrr ae nanan Eee a Small figures indicate the instars. se : THE CONCHUELA. , 51 Bugs were picked from the plants on this tabla between the exam- inations of July 11 and 15 and again between the examinations of July 27 and 29, the first pickings averaging about 7 per row and the second averaging between 5 and 10. The removal of these may be taken into consideration, although affecting the general results but little. The data obtained by these examinations show that con- chuelas, or in a broader sense the Pentatomids, reached their maxi- mum numbers in this field about July 20, and during the following week there was a decrease of nearly 50 per cent. Considering the picking just previous to the last examination, a , continuance of the natural decrease in numbers is evident. Following the same general plan, four additional examinations were made on July 15 for the purpose of showing the numerical status of the bugs on that date throughout the tabla. The length of the tabla being about one and one-quarter miles, five examinations were made, one at each end and three between, at places estimated to divide the tabla into fourths. Table XXII shows the data obtained by these examinations. TasLe X XI1.—Numerical status of Pentatomid bugs in field of 120 acres, July 15, 1905. Number Number of Number | of plants x ae of | Number of | Number of otal adult sae ase adults Thy- Examination of plants | infested nymphs P.| adults P anta sp. Pentato- No. in r. rao dults ligata per ligata on sayi per. er 100 mids per OW y 100 plants. | 100 plants.@| 100 plants. y 100 plants. p plants. Weiss stasis ote 99 30 52 IPS} es 3 2 57 ee Oe a 82 26 57 12 15 8 2 67 ee te tcieiciei 103 ily 33 92 14 0 il 34 AIR Sacro its 127, Duo Tors) 0 0 1 8.8 i eae 56 12.5 21.4 0 0 1 22. 4 Motales<: 467 91 ial 16 11 7 189 Average... 93. 4 18. 2 34, 2 3.4 Dee 1.4 37.8 a Small figures indicate the instars. As there were nearly 1,660 rows in the above tabla, it may be esti- mated from the data given that there were on July 15 approximately 60,000 conchuelas in the entire area of 120 acres. Another series of observations made in planta cotton in Zaragoza B, tablas 1—9, also shows a diminution of the pest during the last 10 days of July. 1..1 2.2 70-71 Conifers, food plants of gipsy moth:...-.....25... 22.2252. a ee sepa "44 Corn, food plant-of gipsy moth:..-...--..-.c-.-:-:.275-2 2 #0) er 14 Creosote against gipsy moth egg-masses.............-.-. bs 19-20, 41, 43 Crow, factor in dissemination of gipsy moth-.....2.....-...... = see 27 Cutting and burning against gipsy moth. .-....:........... 2222 18 Dipterous parasites of gipsy moth and brown-tail moth..................-..-. oT Elm leaf-beetle, arsenate. of lead as remedy. ..........-:--..2.2) See 65 Empusa aulice, fungus enemy of brown-tail caterpillars.....................- 70 Euproctis chrysorrhea. (See Brown-tail moth.) . ‘‘Placherie” affecting larvee of gipsy moth. .........2... .- eee 70-71 Forest products and lumber, inspection against gipsy moth and brown-tail MOU. 25h. tle ee) eee a 57-60 Fungous disease of brown-tail caterpillars. --2.... 2.25. 2222582 5. eee Be is 70 Galerucella luteola. (See Elm leaf-beetle.) Garden crops, sometimes eaten by gipsy moth caterpillars...............--..- 14 Gipsy moth, adults, description and life history ....__...-.-./ 222 eee 16 and beanie moth field work by State of Massachusetts ....... 47-49 cost of methods employed........ 69-70 experiments. —..... 25. eee oes 60-62 inspection of lumber and forest products. . ...-..-:¢.32=— 57-60 in the State of Connecticut. ..... 56-57 Maine. 2532 2oae 50-52 New Hampshire. . 53-54 Rhode Island..... 54-56 introduction, to repotts.2-=. ose 9 suggestions to owners of private property in infested districts... 72-74 value to farmer and fruit grower. ve conditions in infested territory at close of Massachusetts state work, 1900. 22222-2502 -222-25.2.28..24 2k aan sr 29 danger of introduction from foreign countries..........-..------- 60-62 ege clusters. method of destruction. - .-.-..... 5... .-2e3= eee 19 eggs, description and life history. .--... . .2:-.-4 5-32 12 experimental: work in control. .-._:-=-..3: 2222. eee 62-63 importance as an insect pest in this country ............-------- 9-10 mitroduction and spread in this country ..-. 2... 3a 9-10 larvee;.description and lite: history 2.2. .222.. 2202.33 eeeee See 13-15 in younger stages can not ‘eat pine... |. 3. J. eee 62-63 life history ose... -.2elccehe lei dec ks ek oo eee 12-16 Massachusetis Act. for suppressing it. -:...-..328.2.2 6a 31-35 methods formerly employed in work against it............--.-.- 16-20 now used in fighting it 12.22...) 212... 2 ee 63-70 National work against-1t begune 2.223222. 25-4... eee 37-47 natural enemies natiye to America; ..2.2... 2.2.2... eee 26-27 valieag 6) wae oe Oe oe ce 70-71 outlook for control ..: 2.0.2 58¢-.5+ tae eee 74-76 parasites and natural enemies, introduction..........-.---.----- fg! publications in America treating of 1t...,..-.-..-.-.-- te ae 77-78 pup, description and life history <...2 2022205 2n..c eee 15 INDEX. 3 81 ; Page en moth, record of it im tts mative home./-..<.-... 3. .u.-2------5-----2.-2 11-12 state work against it in Massachusetts, 1890-1900.....-.......... 11 dascontmuance:.. 2... 5 <. 28-29 discontinuance, results.... 30-31 funds expended.......-..- 29 progress made. 22.22.2222: 27-28 FESUMPLIOM 2. oc. kil 31-37 Grass, sometimes eaten by gipsy moth caterpillars.................--...2-2..-- 14 Pick TOOU. plant Ol gIpsy, MOUN 4.. 2222 igre ee oot Fi. Se eee be one 15 Hickory for reforesting purposes in district infested by gipsy moth............ 74 Hymenopterous parasites of gipsy moth and brown-tail moth..-....-.........- 2h Insect enemies of gipsy moth and brown-tail moth native to America......... 26-27 Juniper, practically immune from attack by gipsy moth...............-..... 14 Lumber and forest products, inspection against gipsy moth and brown-tail ieee ee PPE N51 LIE Ree Nate) ce Set ae hs PLAC ee eee 57-60 Maple for reforesting purposes in district infested by gipsy moth......... cote 74 moeaeprecterred-iood. plant of gipsy moth: -..-:.....2../-222 22-2. 022 ene 14, 74 Oak, me meen ood planter Sipsy-moth. 1... .-.-2.. cc wee ee nn 14 Ocneria dispar. (See Gipsy moth.) Orchards, proper treatment in districts infested by gipsy moth and brown-tail WLU. ce ecscculnncd Stim el berate a Osta Penne 73 Pentatomidz, enemies of gipsy moth and brown-tail moth................... 27 Pine for reforesting purposes in districts infested by gipsy moth.............. 74 noeteaten by small sipsy moth caterpillats............-.---.-.-.....- 62-63, 74 Pmremiond plant ot eipsy moth... 2.2.2... 02. 6..2-2.6 2222.20 ele. 14-15 Porthetria dispar. (See Gipsy moth.) LP PO QE OS CTS 1000) 8 9 ee ee a a 19 Scouting against gipsy moth..........- Shae E is, Sen, SAE MRM etre A ba Oe 16-17 Spatrow. Emelish, enemy of brown-tail moth.........0.-....-...-.2-..---- eee 24 Pam ts SUSY MOM. 2 5.2. 5.22 fe yeti ee = be Se ee ee ee 1 improvements in machinery.................... 63 OUMMPUS MIMO ME UIS eC el RA acuta hs aes it ee ee 65-68 SPeeomoummminat Gi Gipsy MOth. 222.23 4 <.- 2. de ee de eee eens dae cee 1 Tametetoor, lise aeaimst Sipsy Moth... 2.24. Se. e. se. ee ec ee tee eee 39-40, 63-64 Toad enemy ot cipsy moth-and brown-tail moth: .....2.......:....22. 24 Dy, Miatlows, preierred tood plants ot eipsy moths. :.:..-.....-...522..0022-25.0 2 14 PiWwilia -diseaseorripsy moth caterpillars. .....c.:.2-4.s0-2. 2.5.22. . eo. 2. 70-71 O 40705°—Bull. 87—-10-—_6 U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN NO. 88. L. O. HOWARD, Entomologist and Chief of Bureau, PREVENTIVE AND REMEDIAL WORK AGAINST. ] MOSQUITOES. - BY L. O.. HOWARD, Pu. D., aeve Chief of. Bureau. Issurp June 20, 1910. eh Ea < ‘eonian aya bo Fd / x ( (2. JUN 20 1310 e. \ Vik | 2 q as @ t i Onal Ni) use \ |. eae . WASHINGTON: , ae ' < GOVERNMENT PRINTING OFFICE. FORA? 1910. £5 xe by x \ > \ -U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN NO. 88. L. O. HOWARD, Entomologist and Chief of Bureau. PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. BY L. O. HOWARD, Pu. D., Chief of Bureau. IssuED JUNE 20, 1910. ee re ¢. =e , I => if ES 4 a Zap : 4) WASHINGTON: GOVERNMENT PRINTING OFFICE. 1910. cee BUREAU OF ENTOMOLOGY. L. O. Howarp, Entomologist and Chief of Bureau. C. L. Maruatt, Assistant Entomologist and Acting Chief in Absence of Chief. R. 8S. Currron, Executive Assistant. . W. F. Taster, Chief Clerk. CHITTENDEN, 1n charge of truck crop and stored product insect investigations. eos A. D. Horxins, in charge of forest insect investigations. W. D. Hunter, in charge of southern field crop insect investigations. F. M. WEBSTER, in charge of cereal and forage insect investigations. A. L. QUAINTANCE, 7n charge of deciduous fruit insect investigations. E. F. Puiuuips, in charge of bee culture. D. M. Roaers, in charge of preventing spread of moths, field work. Rouia P. Currie, in charge of editorial work. MABEL CoLcorD, librarian. 2 Wnws hela i? ai LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY, Washington, D. C., March 29, 1910. Sir: I have the honor to transmit herewith the manuscript of a bulletin on preventive and remedial work against mosquitoes. It is my hope, with your approval, to follow this with four other bulletins and a circular, all relating to mosquitoes, and to prepare the series in such a way as to bring about a measurably complete consideration of these baeniay ie and dangerous insects for North America. I respectfully Se evicatel that this manuscript be published as Bulletin No. 88 of this Bureau. Respectfully, L. O. Howarp, Entomologist and Chief of Bureau. Hon. JAMES WILSON, Secretary of Agriculture. CON LENAS. IIR IEEE re els Or Si AR ar i ts AY A AS RS OWASSO bole ME MEMEMOHEIOILES: Soo Behl eile. de Y Paes on Be Ae we isles bee emerson Sg hac ot ee can Mets Sut. Sah A Perera amd CUNnOpIes..o 5... 6-22. se ws ee PUES TRONS gees URES Yen PEEP LPeO ING Dlaces! 20122. elie steko eee eee ones eioss DeEMENEPIN CEO INE BIACES fo Ls os eis Se as oo a ele te bea abet. pone 2 Deterrent trees and plants....-..-..- pti Aa ed SAW AE Th OS RUAN BORE pCR Ae nA Le sd geo aes IR i a ge Ake meen i ed ie hn aaa, ay ela 2 E08 USER UG SINS 5 SR a re a re an ee gee ee Ce meee ge ane MP EMIRE CHM Raa Py te) BS ae ts id eS no Hye wi oe ELSES bs 22 ea EPA i ea roe Wig ae Ag mer ge iat ie SePEnemremmnNaAiS. fo 8 oe a el ree ee tee Pyrethrum or chrysanthemum. . Pia Cee ONS alee oa re AOD, Bays ve ce ReaD BUI eR A ei ews ea Say a Peds Sh Deed Gua k~ o MNEInETIG CI rary ecb he ge Ys A oN ohne Powe hee ae S IMPRESS eee EEO INGING Eten ey et ee a ee Leh a SS os iS pee tor catching adult mosquitoes... 2.2: 22-52... 22222-22222. -+ 22-228: En anOac iba bites. 255°. 80s). 2s aba le tt see ne sede. lace EERE ey oP Sih et WS aah Seca Milo SOs oe LEE Ae uc EENERILE TL WEE ate osu en tinh ee at a ag See ee were a Saye ae bas MU OL tats this Ue Sead i ne ak Pe ok) ae precron reclaimed: lands: 002022. 2 ee ke ere ee sees. ee ee ee Sepee ere tantGit WOEKE, ¢. 5.2 fe ta eke oes ol to ene eer lands iN Cw Jersey! o.oo 2 a nic 2 Ba be ee ereele Das oe: The practical use of natural enemies of mosquitoes..................---.----- Salamanders, dragonflies, predaceous mosquitoes, and fish..............- Fish introduced into Hawaii to abate mosquitoes..................----- (LETS DES UICSTS: 27 Bri 1°21 ge ot So eke On a Semen MaChming Hast witied: j0 80a Me eee Se Pevere airs Milne 8 a ee on Pe Mae erate. Soa Ske MERIT EMEREN OS) 02 3.) ts ole tee teow ol ll el Deeeeeetionh ior COmMmMnMILy Work... 25:4.) 421256 09s... 2 eS The importance of interesting children eee ere Meee IRLVG CETHANT Yi cr. 2 ee ee ee ae ee min dane river irontigin Hey pt. +... 02, -22 aes -h- 52 dca lee eee Examples of mosquito exterminative measures in different parts of the world guages ihe sanitary results following them... 5/J......1..2...+.---.--.---+. eee ape eI LN Lakes 25 12 a rg Ns ue Ey aoe The work in Habana during the American occupation, 1901-2.......-.--- 5 6 | CONTENTS. Examples of mosquito exterminative measures, etc.—Continued. Page. Work. .at the Isthmus of Panama. ./o40. 2b Slee ee ee Pes Oy 93 Work in Rio'de Janeiro. . 2 220.25 5s.222 2b o2 2 fe. tee 95 Work in. Algeria... 222.9220. 2S. 20 SISA 2s bese ee 98 Work in Ismailia...) . 22 Pa ee 100 © Work in Veracruz. (000.22 So eva ee ee ee 100 Workin Japan. . 6.05 2<2 272 Eb 2 Ge ae ee - 102 Antimosquito work in other parts of the world. ...-.....-..-....-...---- 104 Conclusions. 2.5232 0 eet te eee i 114 PENGSR. bo. ee a aS ek 117 PREVENTIVE AND REMEDIAL WORK AGAINST 3 MOSQUITOES. INTRODUCTION. For many centuries humanity has endured the annoyance of mos- quitoes without making any intelligent effort to prevent it except in the use of smudges, preparations applied to the skin, and in re- moval from localities of abundance. And it is only within compara- tively recent years that widespread community work against mos- quitoes has been undertaken, this having resulted almost directly from the discoveries concerning the carriage of disease by these insects. As obvious a procedure as it might seem to be, the abolition of mosquito-breeding places is a comparatively new idea. ‘The treat- ment of breeding places with oil to destroy the larval forms is, how- ever, by no means recent. As early as 1812 the writer of a work published in London entitled ‘‘Omniana or Hore Otiosiores” sug- gested that by pouring oil upon water the number of mosquitoes . may be diminished. It is stated that in the middle of the nineteenth century kerosene was used in France in this way, while in the French quarter in New Orleans oil was placed in water tanks before the civil war, the idea having possibly come from France to New Orleans or vice versa. Another early recommendation of the use of oil was given by an anonymous writer in the Magazin Pittoresque,? in an article on the ‘‘Mosquito and Its Metamorphoses.’’ The phraseology translated into English is as follows: When one has recognized that the ponds or ditches existing close to houses are swarming with the larvee of mosquitoes, one can immediately destroy this dangerous race by spreading on the surface a little oil, which extends in a very thin film and prevents the little insects from coming up to breathe. This proceeding is especially easy to put into practice upon the irrigating tanks in gardens, since it is in such places that the greatest number of mosquitoes develop. Again, quite recently, Mr. John P. Fort, of Athens, Ga., has com- municated to the writer that about the year 1854, while his father, Dr. Thomlinson Fort, was physician to the penitentiary at Milledge- ville, Ga., a place of about 2,000 people, the institution had become so infested with mosquitoes as to cause much complaint. Doctor a Vol. 15, pp. 178-182, 1846. 8 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Fort had the matter investigated, and it was found that the mos- quitoes originated in the tan vats of a tanyard in the penitentiary and in a large cistern attached to the livery stable in the city. He ordered oil to be put upon the water in the tan vats and the mosquitoes were destroyed. In 1892 some exact experimentation was windoreiae by the writer in Green County, N. Y., which indicated the amount of kero- sene necessary for a given male surface, and the duration of effi- ciency. These experiments also showed that adult mosquitoes are captured by a kerosene film—that is to say, adult females alighting on the surface of the water for the purpose of depositing eggs or for drinking are destroyed by the kerosene before the eggs are laid. The account of these experiments, published in Insect Life,* attracted much attention by persons interested and received extended news- paper notices, from which it resulted that practical work on a larger or smaller scale was carried on with success by H. E. Weed, at the Mississippi Agricultural College; by Dr. John B. Smith, on Long Island; by Prof. V. L. Kellogg, on the campus of the Stanford Uni- versity of California; by Rev. John D. Long, at Oak Island Beach, Long Island Sound; by Mr. W. R. Hopson, near Stratford, Conn.; by Mr. R. M. Reese, in Baltimore; by Mr. W. C. Kerr, on Staten Island; by Mr. M.J. Wightman, at an Atlantic coast resort; and by Dr. St. George Gray, in the British West Indies. The publication of the extensive mosquito article in the bulletin on household insects ® by the writer and Mr. Marlatt intensified this interest, and was pro- ductive of other successful work. . With the discovery of the disease-bearing relation of mosquitoes, first with malaria and next with yellow fever, public interest in their destruction became intensified, and large-scale remedial work was done at many points. Bulletin No. 25,° by the writer, devoted con- siderable space to the subject of remedies, and indicated in the main those remedies which are of use to-day and are to be recommended upon a sound basis of practical experimentation. It is probably unfortunate that the writer in this bulletin laid so much stress upon the use of petroleum as to obscure in a way the much more vital measures of thorough drainage and the complete abolition of breed- ing places; but the idea that was prominent in his mind at the time the bulletin was written was ‘‘Let us stop mosquito breeding at once in an economical way, and then let us take our time in more expensive, more elaborate, and more radical measures.’”’ The same criticism can be made and the same partial, though by no means a2 Vol. 5, No. 1, pp. 12-14, September, 1892. 6 Bul. 4, n.s., Div. Ent., U.S. Dept. Agr., 1896. ¢ Bul. 25, n. s., Div. Ent., U. S. Dept. Agr., 1900. INTRODUCTION. 9 satisfactory, explanation in the case of a book entitled ‘‘Mosquitoes,’’? published in the spring of 1901; but both bulletin and book served a good purpose, and together undoubtedly helped to start, to a great measure, the antimosquito work which has since been carried on in ‘the United States. Practically beginning with 1901, there has been a rather rapid in- crease in antimosquito work by individuals and communities,. but this work has not progressed with anything like the rapidity demanded by the distressing conditions of many localities and in fact of great areas. Yet itis probably accurate to state that more effective work of this kind has been done in the United States than in any other country. This is probably due to the greater prevalence of mosqui- toes in the United States than in any other highly civilized country, but the well-known practical character of the American people is also an element. ‘During the summer of 1900 Mr. W. J. Matheson carried on some admirable antimosquito work at his large place at Lloyds Neck, Long Island, N. Y. This work was thoroughly done and was most success- ful, no mosquitoes breeding where they had previously swarmed to such an extent as to render the localities uninhabitable. In the autumn of 1900 there was a migration of salt-marsh mosquitoes to Lloyds Neck from salt marshes bordering on Center Island. Mr. Matheson induced the practical residents of Center Island to take up extensive work during the summer of 1901, and this work was carried through in a very perfect manner by Mr. H. C. Weeks, engineer in charge, and was described in the Century Magazine for July, 1902. In the summer of 1901 was also begun by far the largest piece of work as yet undertaken. It originated on the ‘‘Northern Shore” of Long Island, in the regions between Hempstead Harbor and Cold Spring Harbor, and was carried on under the auspices of the North Shore Improvement Association, a group of wealthy and prominent residents of this part of the island. The work during the summer of 1901 included an almost microscopic survey of the region and the preparation of a map showing the breeding places of the several kinds of mosquitoes. It included also the preparation of reports by ento- -mological experts, a report by Professor Shaler, of Harvard Univer- sity, on marsh areas and related subjects; an account of the work done on Center Island during 1901; and engineering reports, includ- ing recommendations for treatment, by Mr. H. C. Weeks. A volume was published in the spring of 1902 entitled ‘‘ Reports on Mosquitoes, with Map,’ which forms a very sound basis for thorough ocean-shore community work for some time to come. Following the survey of the work by the North Shore Improvement Association in 1901 there were carried on by private individuals and by the association in 1902 a‘*Mosquitoes.”’ By L. O. Howard. 1901. b New York, 1902. 10 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. certain remedial and preventive operations. One of the most inter- esting of this series was performed on the estate of Mr. W. D. Guthrie. By means of a dike and a sluice gate a large marsh area was drained, and the breeding of the salt-marsh mosquitoes was stopped. A stretch of 75 acres of land was reclaimed and the soil was disintegrated and properly treated, with the result that cabbages, turnips, and — celery were grown at the close of the summer of 1902. The year of 1902 was also marked by the first effort to secure anti- mosquito legislation from one of the United States. The state ento- mologist of New Jersey, Dr. John B. Smith, backed by an intelligent public sentiment, tried to secure the passage of a bill by the state legislature during the winter of 1901-2, appropriating $10,000 for the purpose of investigating the possibilities of the wholesale destruc- tion of the salt-marsh mosquito and other kinds of mosquitoes. The bill passed one branch of the legislature, but failed in the other branch. The governor of the State, however, was able in other ways to provide Doctor Smith with a limited sum to carry on researches. In this work he discovered a number of most interesting and vitally important facts concerning breeding habits of the salt-marsh mos- quitoes, indicating that the breeding places of these species are more or less circumscribed, and that the matter of control is by no means as expensive as it appears at first sight, and it was these discoveries that eventually led to the passage of the law which will be mentioned later. : Admirable community work was taken up during 1901-2 by cer- tain New Jersey towns, notably South Orange, Elizabeth, Montclair, Monmouth Beach, and Summit. Independent work was begun in Greater New York under Doctor Lederle, and the mapping of mos- quito breeding places within city limits was begun. Independently, the health officers of Brooklyn, Jamaica, and Bronx Borough began efficient work, while the simmer resorts of Arverne and Woodmere reduced the mosquito supply by intelligent operations. At Willets Point intelligent and efficient work. was carried out on a small scale. In Massachusetts interesting and important work was done at Brook- line and at Worcester. In Brookline the board of health first consid- ered the work in August, 1901, and in September all the breeding places of the malaria mosquito and of the other mosquitoes were treated. In 1902 all pools, ponds, ditches, and other breeding places, including catch-basins, were located on the town map. The approxi- mate areas were determined and the number of catch-basins ascer- tained. Breeding places of Culex and Anopheles, respectively, were determined, and also the places where both the species were breed- ing—this being done in order to ascertain the proper intervals for treatment; that is, whether every two weeks or every three weeks. Public dumps and other places where accidental receptacles of water. INTRODUCTION. — 11 might be found were also located on the maps. Light fuel oil was used on all breeding places. The public dumps were found to be very important in the work, since many accidental receptacles, like bottles, cans, wooden and tin boxes, and the like, were to be found. Where these were breakable, they were simply broken; when not, they were carried and dumped into pools to assist in filling these. _ This Brookline work was so thorough that the community was greatly relieved from the mosquito pest, although in the autumn some low meadows near the town, where drainage work had been postponed, were found to be breeding mosquitoes in great numbers. At Worcester the work was of the most interesting kind. Dr. Wil- liam McKibben and Dr. C. F. Hodge started the crusade. Breeding places were mapped and photographed and public lectures were given. The school children of the several grades were interested and were organized into searching parties. Many breeding places were filled, and others were treated with kerosene. A strong point was made in Worcester, by those engaged in the crusade, by the preva- lence of malaria in many places in the city. The relation between the mosquito-breeding places and the houses where there were ma- laria patients was effectively pointed out, and a map was prepared showing the exact distribution of malaria in the city, and photographs _ were made showing the character of the breeding places of the malaria mosquito. It is probable that these Worcester efforts to interest the school children were the first made in this direction, although the idea was carried out to a much greater extent later in San Antonio, . Tex., under Doctor Lankford, as will be pointed out on subsequent pages. Other work during the-summer was carried on at Pine Orchard and Ansonia, Conn., at Old Orchard Beach, in Maine, and on the campus of the Michigan Agricultural College, in Michigan. Strong efforts were made during the summer to start work at Baltimore, but for a time the city council refused to make appropriations. At Atlanta, Ga., the sanitary department used a large amount of kero- sene in the stagnant pools and swampy places around the city, and warned the citizens to watch their rain barrels and keep their gutters open. A great many pools of water were drained, and in the negro quarters of the city the sanitary inspectors were constantly on the lookout for standing water in buckets and other chance receptacles. The matter was taken. up with the county commissioners, and the area of preventive measures was extended toward the close of the season. In Savannah some work was done, and the number of mos- - quitoes reduced very considerably. Oil was used diligently by the - sewer-cleaning forces, and was placed in the catch-basins. So great was the relief that many people in Savannah for the first time used no mosquito bars. At Talladega, Ala., under the direction of Dr. B. B. Simms, antimosquito work was commenced early in the season, 192 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. and was carried out systematically and thoroughly. No place that - could possibly prove a breeding place was overlooked. The applica- tion of kerosene was repeated several times during the year. St. Louis took up the work early in July, and the municipal assembly made an appropriation for supplies. The health department, how- ever, was hampered for lack of men, and little work was done. Pack were the early steps in the mosquito crusade in this country. Many other communities have taken up the work since 1902. Some, through inefficient work, have allowed their efforts to lapse, and have become more or less indifferent. Others have gone ahead and have spent considerable sums of money in their mosquito fight. In the early days of mosquito warfare there was great indifference combined with incredulity as to the danger from mosquitoes, even among the medical profession, and particularly in the South. This indifference and incredulity, however, have now, for the most part, passed away. Boards of health very generally appreciate the desir- ability of antimosquito work, and as rapidly as town councils can be induced to appropriate the necessary funds the work is going ahead. Excellent antimosquito work has been carried on during the past few years in Honolulu, backed by rather modest funds, under the direc- tion of the then entomologist of the Hawaiian Agricultural Experiment Station, Dr. D. L. Van Dine. In Porto Rico some work is being done, as well as in the Philippines, under the United States Government. In Cuba and in Panama the work has been of a standard character and the operations at these points will be more fully mentioned in subsequent paragraphs. In other. parts of the world many striking examples of the value of antimosquito work have been shown comparatively recently, and several of these will be detailed later. PROTECTION FROM BITES. PROTECTIVE LIQUIDS. A number of different substances have been in use to rub upon the skin or to put near the bed as a protection from mosquitoes. Spirits of camphor rubbed upon the face and hands, or a few drops on the pillow at night, will keep away mosquitoes for a time, and this is also a well-known property of oil of pennyroyal. Oil of peppermint, lemon juice, and vinegar have all been recommended for use as protec- tors against mosquitoes, while oil of tar has been used in bad mos- quito localities. A mixture recommended by Mr. E. H. Gane, of New York, is the following: Oil of Iavender 202 2:55 4) 96263 ee eee do. eee. | Lt Wejan' Gn ve a PROTECTION FROM BITES. 13 The oil of citronella has come into very general use in the United States in the past few years. The odor is objectionable to some people, but not to many, and it is efficient in keeping away mosquitoes for several hours. A mixture recommended by Mr. C. A. Nash, of New York, composed of 1 ounce oil of citronella, 1 ounce spirits of cam- phor, and one-half ounce oil of cedar, has been the most efficacious mixture tried by the writer. Ordinarily a few drops on a bath towel hung over the head of the bed will keep Culex pipiens away for a whole night. Where mosquitoes are very persistent, however, a few drops rubbed on the face and hands will suffice. This mixture, in the experience of the writer, has been effective against all mosquitoes except Aédes (Stegomyia) calopus, the yellow-fever mosquito. This mosquito begins to trouble the sleeper at daybreak, and by that time the potency of the mixture has largely passed, and one is apt to be in his soundest sleep. If, however, one could arrange to be awakened just before daybreak and apply the mixture, returning for the last nap, it is probable that it would be efficacious. Fishermen and hunters in the north woods will find that a good mixture against mosquitoes and black flies can be made as follows: Take 24 pounds of mutton tallow and strain it. . While still hot add one-half pound black tar (Canadian tar), stir thoroughly, and pour. into the receptacle in which it is to be contained. When nearly cool stir in 3 ounces of oil of citronella and 14 ounces of pennyroyal. Oscar Samostz, of Austin, Tex., recommends the following formula: Mrenmeninanetlt 2 sk ae Sas hock ea eee sya See A ivounee 21 1 MMeNNRV ArelING pears Moore eee ee a Sin ees 2S ounces.. 4 Apply freely to exposed parts. Doctor Durham, of the English Yellow Fever Commission, Rio de Janeiro, told the writer that he and the late Doctor Myers found that a 5 per cent solution of sulphate of potash prevented mosquitoes from biting, and that they were obliged to use this mixture while at work in their laboratory in Brazil to prevent themselves from being badly bitten. 7 An anonymous correspondent of American Medicine, who signs himself F. A. H., says: I would advise the use of the oil of cassia, for the odor is not offensive to human be- ings and it is an irritant poison to all kinds of insects. Besides, its power remains for a long time after it has dried. Pure kerosene has been used for this same purpose. An excellent example of its practical use came to the writer in a letter from Dr. W. H. Dade, an army surgeon, writing from the Philippine Islands under date of November 15, 1901. | He stated that during November, 1900, while traveling up the Cagayan River on the steamer Raleigh, they were bothered greatly by mosquitoes both during the day and night, Culex and Anopheles 14 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. : both being present and breeding in fire buckets along the sides of the vessel. The buckets were teeming with larve. They did not seem to have thought of putting kerosene on the buckets in order to stop the breeding, but at the suggestion of Doctor Dade a rag was sat- urated with kerosene, the face, hands, and feet were smeared with it, and the rag was put where it could be conveniently reached. When aroused from sleep by mosquitoes another application was made. ‘“Those who had not used these means before seemed perfectly sur- prised at the splendid immunity gained. The odor and the greasy feeling imparted were the only drawbacks to its use.’”’ Doctor Dade continued to experiment with this remedy after his return from an unsuccessful attempt to capture General Aguinaldo, and found that the addition of 1 part oil of bergamot to 16 of kerosene imparted an odor scarcely objectionable, and at the same time added sufficient body to the kerosene to prevent evaporation in less than six to eight hours. After that, when the soldiers had to leave the post, and after it became impracticable to carry cans with them in the field for a long or pro- tracted march, this mixture was used, with the result that the list of Inalarial patients was noticeably shortened. The oil of bergamot was hard to obtain and is too expensive to be used wholesale, but the soldiers rarely objected to the odor of kerosene and the bergamot was not continued. | In moist tropical regions where one perspires profusely, the oily mixtures considered under this heading applied to the skin are transient in their effects. Under these circumstances they should be applied rather liberally to the clothing, particularly about the neck and wrists. SCREENS AND CANOPIES. Such obvious measures as the screening of houses, the use of net- ting for beds, and the wearing of veils and gloves after nightfall in badly infested regions, need no consideration in detail. But even in such an apparently simple matter as house screening certain points must be taken into consideration. It may be incidentally stated that with proper treatment of breeding places screening is unnecessary. The expense to which the people of the United States go for screens against mosquitoes and flies is enormous, and has been estimated at $10,000,000 annually. If this expense were at all necessary it should surely be thoroughly done. In screening a house, as Dr. John B. Smith has pointed out in his. Bulletin No. 216 of the New Jersey Agricultural Experiment Station, the attempts frequently fall far short of protection: Adjustable, folding, or sliding screens are never tight, and when the insects really want to get indoors they work their way patiently between the two parts of the screen or between its frames and the window. But even a well-fitted screen either sets tightly into the frame or, running like a sash, may offer leaks when a window is only partly PROTECTION FROM BITES. 15 opened. * * * There is abundant opportunity for the insect to get in between the net and lower cross bar; in fact, there is no real protection at all. Where the netting is fixed to the outside of its frame, so that there is no space between it and the lower part of the sash, the insects nevertheless find their way in between the window sashes. * * * Jt has been already said that the mosquitoes will, in certain seasons, attempt to make their way through the screens, and they have less trouble with wire netting _ than with any other because the meshes are even in size and the strands smooth. Some of the fabrics used for nettings, especially of the cheaper grades, have the threads so fuzzy that it is simply impossible for the mosquitoes to make their way through, and they rarely even try it except where there is a tear, or where the threads have been spread apart leaving an unusually large opening. Where an onslaught is made on wire netting it can be checked by painting lightly with kerosene or oil of citronella. I have tried both and found them successful. In addition to these mechanical difficulties it often happens that the cellar and attic windows of houses are not screened. This is a great mistake, since mosquitoes will enter these windows and pass the winter in both cellars and attics. With regard to bed canopies there is reason for the greatest care. There should be ample material to admit of a perfect folding of the canopy under the mattress, and the greatest care should be taken to keep the fabric well mended. It often happens in mosquito regions that little care is taken of the bed nettings in the poorer hotels, and it is necessary for perfect protection that a traveler in the Southern States should carry with him a pocket housewife and should carefully examine his bed netting every night, prepared to mend all tears and expanded meshes. Veils and nettings for camping in the Tropics are absolute neces- saries. Light frames are made to fit helmetlike over the head and are covered with mosquito netting. Similar frames readily folded into a compact form are made to form a bed covering at night, and every camping outfit for work in tropical or malarial regions should possess such framework and plenty of mosquito netting as an essen- tial part of the outfit. An illustrated advertisement in Ross’s admirable Mosquito Brigades shows a folding-hood mosquito net especially for the use of travelers when taking rest. This is 63 feet long, 4 feet wide, and 2 feet high. It is a frame arrangement which can be opened by the traveler so as to envelop himself when he is lying down. The frame is easily carried in the hand, being only 40 inches long by 4 inches i in diameter when folded. There is also given an illustration of a small, compact mosquito house for use by travelers while writing, reading, or taking their meals. It is large enough to contain two persons seated, and is constructed with a frame which is easily portable. The frames are manufactured by a firm of surgical-instrument makers in Liver- pool. No doubt other apparatus of the same kind is manufactured and to be purchased at large outfitting establishments, such as the army and navy stores in London, Y ; iy be by bos 4 +: FP a 16 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Some attention has been paid to the subject of the size of the mesh of screens with especial reference to the yellow-fever mosquito. Working party No. 2 of the Public Health and Marine-Hospital Service, at Veracruz, conducted a few experiments to determine the question of the size of the mesh. Their experiments were con- ducted by placing screens with a varying number of meshes to the inch over breeding jars and putting bananas, sirup, and other food on the other side so as to tempt the foe mosquitoes to pass through. The fruit and other food was placed in a jar which was inverted over the mosquito-breeding jar, and a piece of gauze or net- ting was inserted between the two jars so that the mosquitoes would have to pass through the meshes in order to appear in the upper jar. As a result it was found that both males and females passed through a netting containing 16 strands or 15 meshes to the inch, but could not pass 20 strands or 19 meshes to the inch. It therefore became evident to these observers that the large-meshed mosquito bars ordi- narily used in Veracruz would not offer proper protection and that window screening must also be of a finer wire than is sometimes employed. Goeldi refers to this screen question, both in regard to the yellow- fever mosquito and to the common rain-water-barrel mosquito, in connection with some very interesting observations about the range of variation in the size of the individuals of the same species, a fact which is frequently noticed with other insects but to which special attention has not been called elsewhere with mosquitoes. Frequently I have observed, both in Stegomyia fasciata and in Culex fatigans, alongside of individuals of normal stature individuals very much smaller—veritable dwarfs. This observation may be made on specimens captured in freedom as well as on those in captivity, in this last case the phenomenon repeating itself rather frequently. There are sometimes born individuals, both males and females, so small that they easily pass through the mesh of wire gauze much closer than the mesh of ‘‘Grassi’s gauze” which to-day is produced on a large scale in Italy with a view to the prophylaxis against the Anopheles and malaria (Grassi, himself, recommends a gauze that shall not have less than nine meshes in 14 centimeters of distance, which corresponds to little linear squares 1.7 mm. to the side). The government of the State of Para imported for my experiments from Italy under this name a gauze which had but six threads to 14 centimeters of linear extension, corresponding to squares of 24 mm. along one side. I refer particularly to this last brand, which I consider suffi- cient as a rule for application to hospitals to impede the invasion of mosquitoes from the outside, but which I found, nevertheless, insufficient for the walls of my cages destined for experiments on mosquitoes like Stegomyia fasciata and Culex fatigans in captivity. In general, the phenomena of macrosomia and microsomia in plants and animals are related directly with greater or less abundant nutrition, and I do not believe that the quoted dwarf race of Stegomyia and Culex is to be explained in any other way than by a sparse alimentation and a delayed development in the larval stage. On this point I have at hand experiments in proof: Larve reared in clear water—that is to say, relatively poor in assimilable substances—gave me imagos of small stature. Furthermore, it is yet to be shown that J am deceived in my opinion that the PROTECTION FROM BITES. LZ: frequency of dwarf individuals captured in freedom is not notably greater at certain periods, assuming almost the character of a rule. Thus this year [1905], in the last weeks of October and November, before we entered fully upon the rainy season, I got the impression that the females of dwarf dimensions were particularly numer- ous. I doubt that this is the work of a mere accident; it is very possible that the frequency of dwarf individuals, normally possible during the whole year, may be periodic and represent a case, somewhat diminished, of what is called in entomology “dimorphism of seasons.’’ ‘Theoretically there can be no serious obstacle in accepting the argument that in the height of the dry season, with the growing lack of waiter, the conditions of life for the larvee become more difficult, thus favoring the generation of mosquitoes below the normal dimensions. Impoverished water and reduced food may really, as we have seen above, oblige the larva to take two or three times the period normally necessary for its development and to acquire the necessary growth for its - metamorphosis. I have the feeling that hibernation, in the sense in which this word: is accepted in zoologic literature, may well for the tropical and equatorial Culicidz find its expression in two ways: (1) Delayed development of the larve; (2) dwarfed stature of the imagos. | Note by translator.—Doctor Goeldi enters into long explanation as to hibernation, evidently for the benefit of equatorial readers who might accuse him of the mal-use of technical terms. He refers to the phenomenon of “seasonal lethargy”’ and en- deavors to trace a connection between the circumstances favoring the development of the perfect insects in parallelism with the “periodicity of yellow fever.’’ His final paragraph is as follows:] It would be a mistake to believe that these dwarf individuals of Stegomyia are less aggressive and sanguinary than those of normal stature. They behave in a pre- cisely similar manner; their bites are not less painful, as I have had frequent occasion to prove. A study of the question of mosquito bars or canopies, both for indoors and out-of-doors, has been made by Dr. F. Arnold, the district medical officer of health, northern Transvaal, and he has published an interesting article on the subject in the Transvaal Agricultural Journal for October, 1907, pages 13-15. He illustrates the mesh of different nettings purchased in Pretoria, labeling a netting with a mesh 1 mm. in width as good, one of 2 mm. as doubtful, and one of 3 mm. as bad. These nettings were tested by stretching them over the mouths of three large pill boxes, and in each pill box was put a known number of live, uninjured mosquitoes. The boxes were placed on a chair alongside his bed, where they remained all night, with the idea that by placing the mosquitoes near a sleeper they would be anxious to get at him, and the natural conditions existing in a bedroom would be imitated; that is, there would be a mosquito and a sleeper separated by a net. The conclusions were those above indicated. Doctor Arnold continues his directions in the following words: In this country the bell-shaped bedroom mosquito net is almost always used; box- shaped nets are rarely seen. In Eastern countries the box-shaped net is generally used fixed on toa large four-posted bed; such an arrangement has the great advantage that the net can be drawn tight and there is within it so large a space for the sleeper that his limbs, if uncovered, are not likely to come in contact with the net, 37713—Bull. 88—10-——2 18 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Frequently the bell net has too small a ring at the top and the netting is not sewn on to the calico which closes the ring, but is gathered up above it by a running thread; such an arrangement causes folds to be formed in the net above the ring, and through the grooves of these folds mosquitoes enter freely. Again, the net is often allowed to hang loose on the bed or it is drawn over the whole bedstead on to the ground. When hanging loose it affords very little protection, for it will, during the night, certainly come in contact with the face, arms, etc., which wili be bitten through the net. If placed right over the bedstead, then its lower margin must be heavily weighted with a long and continuous sand bag, and every care must be taken to drive away mos- quitoes which may be sleeping on the dark underside of the mattress; in outlying districts white ants would, in one night, make short work of net and sand bag if lying on a mud floor. How, then, should a net be made and arranged? Proceed as follows: Obtain a ring of wood or iron, in diameter two and a half to three feet; close it with a piece of stout calico; on this calico, around the circumference of the ring, sew the mosquito net very carefully, using netting of the mesh shown as No. 1. Suspend the net to the ceiling in the usual way. Next arrange the bedding as is done on board ship; that is to say, take the upper sheet, blanket, and counterpane and fold the margins inwards at the sides and at the foot; all of the bedding which will cover the sleeper will then lie on the top of the under sheet. Now tuck the mosquito net under the mattress all around, drawing it tight. On going to bed draw out the net at one side, creep in under it, and carefully tuck it back under the mattress. The sleeper is now in a cage; it does not matter how much he kicks about the net will remain true, and, provided that a fair-sized bed is used, there is not much risk ofan unclothed part of the body touching the net. For use on the veldt many kinds of stretchers, etc., have been devised. The writer has used a folding stretcher which carries four thin upright rods. Through eyes in the upper ends of these rods runs a cord, and over the whole structure is placed a box-shaped net. The net sold with the stretcher has its lower margin weighted; it is intended that this lower margin ‘ should lie on the ground. But this is a theoretical arrangement. . First, one rarely gets a flat piece of ground free of grass and stones whereon to place the stretcher; secondly, a sudden gust of wind causes the hanging net to ‘‘ride-up” on the feet of the stretchers; and lastly, a stone or grass lifts up the lower margin of the net. The net, etc., should be arranged as follows: Takea large, long blanket, 7 feet by 5 feet, fold it lengthwise, and lay it on the stretcher to serve as a mattress. Arrange the blankets which will cover you just as the top bedding is arranged for an indoor bed. Tuck in the net carefully all around under the blanket mattress, taking special care to cross the folds of the net around the upright rods. Crawl in under the net and close it in the usual way. The stretcher used by the writer, when opened for use, measures 64 by 24 feet, and stands 15 inches above the ground. The whole outfit (stretcher, rods, and net) weighs 26 pounds and can be packed into a canvas sack measuring 3 feet by 13 inches. SCREENING BREEDING PLACES. What we have said in regard to the size and mesh to be used in window screens and canopies applies equally well to screens over possible -breeding places to prevent the breeding of mosquitoes or the issuing of mosquitoes which have bred therein. In cities in the Gulf States, where the rain-water supply is conserved in large tanks, screening is necessary and is now enforced, Galveston and New Orleans perhaps being the first to make this an important health measure. But rain-water barrels everywhere must also’ be screened ABOLITION OF BREEDING PLACES. 19 in the same way, except where fish are used to kill the early stages of mosquitoes. In out-of-the-way places, however, where it is dificult to get good screens or where the expense of screening is seriously to be considered, a cheap cover may be made for well- mouths or water barrels, such as described by Dutton in his Report of the Malaria Expedition to the Gambia, and which he states was devised by Doctor Forde. This cover consists of a large iron hoop obtained from discarded barrels, to which is fastened all around a piece of stout calico or sacking free from holes in such a manner that a good deal of sag is left in the material. After water is obtained from the well the hoop is thrown over the mouth, and the calico catching on the rim of the well completely closes the entrance and is kept taut by the weight of the iron hoop. This cover is so simple, and, however carelessly applied, must so effectually close the entrance of the tub against mosquitoes that I think it is well worthy of extensive use in the town. Dr. Forde has lately informed me that these covers are now being made in Bathurst, and are sold to the natives for the sum of four pence.¢ ABOLITION OF BREEDING PLACES. In considering this general question just as in considering so many questions relating to mosquitoes, a complication arises from the enormous mass of facts concerning the life histories of the differ- ent species of mosquitoes; facts discovered, for the most part, in the past three or four years. At the time of the publication of Bulletin 25, new series, of this Bureau, the specific habits of but a few mos- quitoes were known and the generalizations drawn from the knowl- edge of these few species were altogether too broad and must now be greatly modified. There is much diversity in the breeding places of different species. Those of the two commonest household mosqui- toes, namely, Culex pipiens in the North and GC. quinquefasciatus and Aedes (Stegomyia) calopus in the South, correspond well to generali- zations formerly named, breeding as these species do in every chance receptacle of water about residences, and their destruction means the abolition of all such receptacles. Where the rain-water barrel or the rain-water tank are necessary they should be screened. In New Orleans and other southern cities the boards of health are now en- forcing, such screening. This should be done with extreme care, a fine mesh wire being used and the fitting being made very perfect. About a given house the waste places in the immediate vicinity should be carefully searched for tin cans, bottles, and wooden or tin boxes in which water can accumulate, and all such receptacles should be destroyed or carted away. The roof gutters of the building ~ should be carefully examined to make sure that they are not clogged so as to allow water to accumulate. The chicken pans in the poultry yard, the water troughs for domestic animals, the water cup of the grindstone, are all places in which mosquitoes will breed and in them a2 8 cents. 20 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. — water should not be allowed to stand for more than a day or so at a time. In the South the water accumulating under water tanks should be treated or drained away. The urns in the cemeteries at New Orleans have been found to breed mosquitoes abundantly. The holy water fonts in Roman Catholic churches, especially in the South, have commonly been found to breed mosquitoes; in some places sponges have been substituted for standing water, and other churches have adopted a closed font, which allows the holy water to issue through a small spigot. In still other churches salt has been put in the water to prevent the breeding of mosquitoes. In slightly marshy ground a favorite breeding place is in the footprints of cattle and horses. In one country village, which contained many small vegetable gardens in a clay soil, during the rainy season mosquitoes were found breeding abundantly in the water accumulating in the furrows in the gardens. Even in the house mosquitoes breed in many places where they may be overlooked. Where the water in flower vases is not fre- quently changed mosquitoes will breed. They will breed in water pitchers in unused guest rooms. They will breed in the tanks in water-closets when these are not frequently in use. They will breed in pipes and under stationary washstands where these are not frequently in use, and they will issue from the sewer traps in back yards in city houses during dry spells in the summer time when - sewers have not recently been flushed by heavy rains. In ware- houses and on docks they breed abundantly in the fire buckets and water barrels. : In country houses in the South where ants are troublesome and where it is the custom to insulate the legs of the tables with small cups of water, mosquitoes will breed in these cups unless a small quantity of kerosene is poured in. Where broken bottles are placed upon a stone wall to form a cheval-de-frise, water accumulates in the bottle fragments after rains and mosquitoes will breed there. Old disused wells in gardens are frequent sources of mosquito supply, even where apparently carefully covered, and here the nuisance is easily abated by the occasional application of kerosene. The same thing may be said of cesspools. Cesspools are frequently covered with stone and cement, but the slightest break in the cement, the slightest crack, will allow the entrance of these minute insects and unlimited breeding often goes on in these pools without a suspicion of the cause of the abundance of mosquitoes in the neighborhood. The writer remembers, for example, on one occasion walking through a New Jersey garden and noticing a covered cesspool with a slight crack in the cement. He remarked upon the danger to the pro- prietor of the estate, who replied that mosquitoes could not possibly vain entrance to the water. Later in the evening, about dusk, the ——— ~ ABOLITION OF BREEDING PLACES. 21 same spot was passed again and a cloud of mosquitoes was seen issu- ing from the crack so abundantly that at a little distance it seemed like a stream of smoke. A little kerosene put a stop to this. Fountains and ornamental. ponds are frequent breeding places, and here the introduction of fish, as indicated in another place, is usually all-sufficient.. It frequently happens, however, that the grass is allowed to grow down into the edges of ornamental ponds and mosquito larve find refuge among the vegetation and so escape the fish. Broad-leaved water plants are also often grown in such ponds, and where these broad leaves lie flat upon the surface of the water, _as they frequently do, one portion of a given leaf may be submerged so that mosquito larve may breed freely in the water over the sub- merged portion of the leaf, protected from fish by the leaf itself, the fish rising from below. It is necessary, therefore, to keep the edges of such ornamental ponds free from vegetation and to choose aquatic plants whose growth will not permit of mosquito-larve protection. In many small country towns, even where there is a water supply, tanks are to be found under the roofs to supply bathrooms. Such tanks should be screened, since mosquitoes gain entrance to the tank- room either through dormer windows or by flying up through the house from below in search of ovipositing places. About a large old house there are so many of these chance-breeding places that only the most careful and long-continued search will find them all. Fre- quent change of water or the use of kerosene will render them all harmless. In community work in cities all of the points mentioned must be borne in mind, and in the portions of the community where the resi- dences are for the most part detached villas, in the absence of swampy suburbs the householders are in the main responsible for their own mosquitoes. There are, however, breeding places for which the municipality may be said to be responsible and these entirely aside from public fountains, reservoirs, or marshes. It seems un- likely that in any general sewerage system mosquitoes may breed in the sewers proper. That they do breed in the catch-basins is well known. The purpose of the catch-basin is to catch and retain by sedimentation sand and refuse which would otherwise enter the sewer and deposit in it. It is intended to be watertight and to hold a considerable body of water which stands in it up to the level of the outlet pipe. Such catch-basins are very commonly used in back yards and at the crossings of streets. The water is removed only by rain or when street or yard surfaces are washed. In dry seasons the period of stagnation may last several weeks, certainly long enough for mosquito breeding. As a matter-of fact, mosquitoes in midsum- mer do breed in such basin traps or catch-basins by millions. In the work against mosquitoes in Brookline, Mass., in 1901 and 1902, 22 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. previously referred to, Culex pipiens was found breeding abun- dantly in them, and more than 1,000 such basins were regularly treated with petroleum. It is a matter of common observation in — the city of Washington that during the usually dry period of late July, August, and September mosquitoes are rather numerous in the northwest quarter of the city where there are no possible breeding places other than these catch-basins, and it is urged that under such circumstances residents make an affine to have such basins frequently treated with kerosene. The suggestion has been made that in cities it may, under certain circumstances, be possible for mosquitoes to breed in water accumu- lating in the troughs of underground-conduit electric railways, but so far as known to the writer no exact affirmative observations have been made. That there is abundant opportunity for water to accumulate in these troughs and that it does so accumulate there can be no doubt. It is true that such water will immediately become very dirty, since dirt of all kinds falls into the slot, and it would also be more or less oily. There remains a chance that mosquitoes may breed in this manner, although Gen. George H. Harries, vice-president of the Washington Railway and Electric Company, of the city of Washington, informs the writer that in his opinion this chance is very slight. DETERRENT TREES AND PLANTS. There are many references in descriptive literature to certain trees and plants in the neighborhood of which mosquitoes are never found. Notable among these are the eucalyptus trees and the castor-oil plant. Of recent years there have been many newspaper notes about other plants and in southern States the chinaberry tree is said to be distasteful. EUCALYPTUS. The statement has often been made that the planting of eucalyptus trees in malarial regions will drive away malaria. This idea had be- come rather firmly grounded before the discovery of the carriage of malaria by mosquitoes. It has been said, for example, that the plant- ing of eucalyptus trees in the Roman Campagna was followed by a notable improvement in the malarial conditions. Eucalyptus oil. has been used to keep mosquitoes from biting. Mr. Alvah A. Eaton, of California, wrote to the Bureau of Entomology, in 1893, that in his opinion where the blue gum grows no other remedy against mosquitoes ~ need be sought for. He further stated that, no matter how plentiful mosquitoes may be, a few twigs or leaves laid on the pillow at night will secure immunity. Another correspondent of the Bureau, Mr. W. A. Saunders, wrote from California that he had planted eucalyptus trees about his house nineteen years previously and that they had DETERRENT TREES AND PLANTS. 23 reached a height of 140 feet. According to his statement, an irrigat- ing ditch ran through the grove, but there was never a single mos- quito larva in the grove, although on both sides of the grove larvze were plentiful. On the other hand, the late Dr. A. Dugés, of Guana- juato, Mexico, wrote the Chief of the Bureau, on September 8, 1900: I have received your very interesting study of the mosquitoes of the United States and thank you greatly for it. Attheend of the book you speak of the utility of euca- lyptus for driving away insects. I have had some experience with these trees. The fresh leaves placed upon the pillow will attract mosquitoes. Thinking that the mosquitoes loved this plant I had placed the branches farther away, but without result. _I have burned the leaves in my chamber, and the cursed beasts have resisted the . smoke. . Eucalyptus trees of many species are now grown generally all through California, and the idea that they drive away mosquitoes -_ must be abandoned. Mr. H. J. Quayle, in Bulletin 178 of the Califor- nia Agricultural Experiment Station, states that in the Burlingame section not far from San Francisco, all of the avenues are lined with eucalyptus trees and mosquitoes are most numerous where these trees are most abundant. In 1901 he captured a pint cup of mos- quitoes immediately under eucalyptus trees. Coyote Point is covered with eucalyptus trees, yet the construction of a hotel on the point was abandoned on account of the abundance of mosquitoes. Edmond and Etienne Sergent, in their antimalarial work in Algeria, had occasion to study the question of eucalyptus and published their results, together with the results of their observations and experi- ments upon certain other plants supposed to be deterrent to mosqui- toes, in the Comptes Rendus des Séances de la Société de Biologie, November 14, 1903. With regard to eucalyptus they show that the railway station of Ouled-Rahmoun, formerly greatly troubled by mosquitoes, was visited by them much less frequently after the cutting down of great eucalyptus trees which surrounded it. The station of Ighzer-Amokran, which is isolated in the middle of a desert plain, is surrounded by a little grove of eucalyptus. Before the windows and doors were screened the rooms were visited every evening by quan- tities of Anopheles. The traveling Kabyles who stopped at this sta- tion would never sleep at midday under the foliage of the eucalyptus, for they said mosquitoes always came down on them. They went under the olives, where they were never bitten. CASTOR-OIL PLANT. During the winter of 1901 a great deal was said in the newspapers about the planting of the castor-oil plants (Ricinus communis) to pre- vent mosquitoes. These notes at that time were mainly based upon a consular report from Capt. EK. H. Plumacher, United States consul at Maracaibo, Venezuela. In this report Captain Plumacher stated TA eee , - BS Sk 24 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. that his residence is surrounded by plantain and banana trees and that he had been troubled in the past by a great number of mosquitoes which gathered in these trees. Following the example of old settlers, he planted castor seeds, which grew up in profusion, with the result that no mosquitoes were to be found among the trees, although he kept the ground well irrigated. Captain Plumacher came to Wash- ington the following year and called on the writer April 18, 1901, bringing with him the seed of the particular variety of the castor-oil plant with which he had noted the result above stated. The seeds were planted upon the department grounds and observations indi- cated that mosquitoes were not at all deterred by the plants. In a report sent in from Progreso, Yucatan, September 17, 1903, United States Consul Thompson makes the following statement: The belief is current among the natives of Yucatan that a few castor-oil plants growing in or near a dwelling will protect the inmates from mosquitoes and certain other noxious insects peculiar to Yucatan. This belief has been to a certain extent confirmed upon experiment by me personally.. My dwelling at one time seemed to be peculiarly acceptable to mosquitoes. I planted a row of castor-oil plants around the courtyard and in a short time the mosquito was as rare as he was formerly a fre- quent visitor. My plants were destroyed by the cyclone and now the mosquitoes are as abundant as formerly. Some of the Venezuela seeds brought by Captain Plumacher were sent to Mr.-J. Turner Brakeley, of Bordentown, N: J. He planted them in.the early summer of 1901, and later in the summer observa- tions were made with the result that mosquitoes were found both on the Venezuela plants and on other castor-oil plants. Mr. Brakeley wrote: | | The castor-oil plant is no good as a ‘‘skeetonal ” protection in New Jersey. It may be a protection against the Venezuela mosquito, but it is no good where the blood pirates of New Jersey are concerned. Giles publishes a letter sent to the Pioneer, an Indian journal, in 1901, in which the correspondent stated that he had seen a recom- mendation of the castor-oil plant as a deterrent for mosquitoes, and in consequence had six plants placed in pots in his room. The result was that the plants were thickly covered by the insects, which seemed “to be actually invigorated by the Baan stizn arte effect: of their new quarters.” The Sergents in Algeria engnesinenied both with the castor-oil plant and with pawpaw ( Carica papaya), on account of the reputation that these plants had as deterrents against mosquitoes. A pawpaw about 90 centimeters (3 feet) high and in good condition was inclosed in a mosquito bar of tulle, oblong in form, with its axis directed per- pendicularly to the window from which the light came. In the end of the bar nearest the window they suspended a raisin grape, for food of the mosquitoes, and a little vessel of water. Then at the opposite. end of the bar they put in four females of Anopheles maculipennis and DETERRENT TREES AND PLANTS. 25 four females of Culex pipiens. They wished to see if the instinct which attracts the mosquitoes toward the light and toward an appar- ent way of escaping, and on the other hand the need of nourishment and water, would induce the mosquitoes to pass the middle portion of the bar which was entirely filled with large leaves of the pawpaw. At the end of four minutes one Anopheles and one Culex had passed from one end of the bar to the other; at the end of ten minutes another Anopheles and two Culex were seen to place themselves upon the pawpaw leaves and they remained there for hours. The mosquito _ bar was left intact for eight days. During this period the mosquitoes _ went everywhere and rested sometimes several hours upon the leaves and upon the branches. An experiment exactly similar was carried on at the same time with Ricinus commums, with precisely similar results. When these experiments concluded at the end of eight days one Anopheles and one Culex were found dead in the pawpaw mosquito bar, and in the Ricinus bar also one Anopheles and one Culex. But in similar cages in another room during the same time six Anopheles out of twenty. had died and nine Culex out of twenty-eight, in the absence of the Carica and Ricinus plants. The authors concluded that pawpaw, eastor-oil plant, and eucalyptus are powerless in their effect on mosquitoes. CHINABERRY TREES. In spite of the statement that chinaberry trees will protect against mosquitoes, observations have failed to show the truth of the state- ment, and in mosquito regions people are quite as liable to be bitten while sitting under a chinaberry tree as under any other tree. Never- - theless there is an observation upon record which suggests that further experiments will be interesting. In the Public Health Reports, Vol. 21, No. 44, November 1, 1901, Dr. G. M. Corput, assistant surgeon, U.S. Marine-Hospital Service, gave the results of certain experiments conducted by hanging cans of water in the branches of different trees, including oak, pine, cherry, and palmetto. He found that in the can hung in the chinaberry bushes there were no mosquito larvee at any time, although larve were found in all of the other cans. . OTHER PLANTS. A number of plants credited with being deterrent to mosquitoes have been mentioned from time to time in the newspapers, some of the accounts being of a sensational character. The New York papers, for example, in the summer of 1906 contained numerous notices of the so-called ‘“‘phu-lo”’ plant introduced from the Tonkin country in French Indo-China by Baron de Taillac. This plant was said to be valuable as a fodder for cattle, and to drive away mosqui- i 26 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. toes. An effort was made to determine the plant, and Mr. W. E. Safford searched the literature of oriental economic botany without finding anything corresponding to it. He found that in the East Indies there is a Verbascum or mullein called ‘‘phul,” the seeds: of which are supposed to be narcotic, and the leaves used like those of tobacco. The leaves of this plant, although not good for general forage, are eaten by camels and goats. Assuming that this is the plant mentioned by the newspapers, there is nothing in the economic literature concerning its use as a mosquito deterrent. Another plant which is said to act as a deterrent is a lavender known as Ocimum viride, a perennial which grows from 3 to 6 feet in height and occurs from Senegambia southward to Angola. Mr. A. E. Ship- ley * states that Major Burdon, resident of the Nupe Province, northern Nigeria, had given him the following account of the plant: A fragment of what turned out to be Ocimum viride was given me in August last at Lokoja, northern Nigeria, by Capt. H. D. Larymore, C. M. G., R. A., resident of the Kabba Province. Capt. Larymore’s notice had been drawn to the plant by a native living in a low-lying part of the native town at Lokoja, who had told him that the natives suffered very little from the swarms of mosquitoes which existed in that pant, as they protected themselves from them by the use of this plant. Capt. Larymore made inquiries and obtained a few specimens of the plant, which grows wild, though not very abundantly, in the neighborhood of Lokoja. These specimens he planted in pots and boxes and kepti in and about his house. The speci- mens I saw were about the size of a geranium. He informed me that the presence of one of these plants in a room undoubtedly drove the mosquitoes out, and that by placing three or four of the plants around his bed at night he was able to sleep unmolested without using a mosquito net. This is very strong testimony to the efficacy of the plant, for the house in which Capt. Larymore was living is, as I had cause to know well in former years, infested with mosquitoes. Mr. Shipley further states that E. M. Holmes in “Notes on the Medicinal Plants of Liberia’? records that when chewed or rubbed the leaves of O. wiride give off a strong odor of lemon thyme, and mentions that Doctor Roberts, of Liberia, entirely substituted the use of the plant for that of quinine in cases of fever of all kinds, giving it in the form of an infusion. Goeldi, in Brazil, has experimented with Ocimum minimum without the slightest beneficial result. He also tested Carica papaya, a plant which has a similar reputation, but also without beneficial result. An account of the Sergents’ experiments with the latter plant has just been given under the heading of the castor-oil plant. Mr. Shipley’s article in the Tropical Agriculturist was reprinted in the British Medical Journal and was quoted in many other periodicals, and in consequence many requests for seeds of Ocumum viride were received at the Royal Botanical Gardens at Kew from many parts of the world. About this time a report was received from Dr. W. T. aThe Tropical Agriculturist, February 2, 1903, pp. 555-556. DETERRENT TREES AND PLANTS. 27 Prout at Freetown, Sierra Leone, and was published by Sir William Thistleton-Dyer in the London Times for July 27, 1903, and in Nature, July 30,1903. Doctor Prout’s report included an account of experiments made with the ‘‘basil”’ plant in relation to its effect upon mosquitoes, and he concludes that his observations ‘‘appear to dis- pose conclusively of the plants possessing any real protective value.” He showed that growing plants have little or no effect in driving away mosquitoes, and are not to be relied upon as a substitute for the mosquito net. He showed, further, that fresh ‘‘basil’”’ leaves have no _ prejudicial effect upon mosquitoes when placed in close contact with them, and, further, that while the fumes of burnt ‘‘basil’’ leaves have a stupefying and eventually a destructive effect on mosquitoes, it is necessary, in order to produce this effect, to bring about a saturation of the air which renders it impossible for individuals to remain in the room. He thinks that cones made of powdered ‘‘basil’’ would, _ when burned, have the effect of driving mosquitoes away, and that the plant to that extent might be found useful. PEAT. An article in the London Times in 1908, written by an anonymous correspondent, refers to the absence of mosquitoes In swamps and marshes with peat. The writer says: ‘‘Given marshy lands.and no peat, mosquitoes abound; given marshy land and peat, there are none.” This‘article was answered by Mr. F. V. Theobald in Nature, October 15, 1908, pages 607-608. Mr. Theobald showed that he had found Anopheles nigripes and Anopheles bifurcatus breeding in the water of peat cuttings in Wales and Somerset and on the far-famed Wicken Fen numbers of Aédes cantans. He stated that mosquitoes are often very abundant in the fens, even where the peat is dug. Besides the species above mentioned he has found Anopheles maculi- pennis and Culiseta annulata in peaty water and near peat piles in northern Wales. : WATER PLANTS. Ordinary pools of stagnant water give birth to thousands of mos- quitoes, the larve breeding with the greatest facility in such water. The presence of algz and certain low forms of aquatic vegetation is evidence of the stagnation of the water, and an algal scum is fre- quently associated with the idea of mosquitoes in one’s mind. But it is perfectly plain that where the water covering of aquatic vegeta- tion becomes extremely dense mosquitoes can not breed, since there is no opportunity for the larve to come to the surface to breathe. Access to air is shut off by the dense covering of vegetation. It has often been a matter of surprise that mosquitoes are not more numer- ous in Holland, where the country is traversed by canals and dikes. 28 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Mosquitoes breed there in ponds and in chance receptacles of water, but the water in the large canals is so constantly agitated by the pas- sage of boats and by the wind that mosquitoes can not breed, and in the smaller ditches and canals the surface of the water becomes so completely covered with a continuous layer of minute aquatic vege- tation (often of considerable thickness) early in the summer that there is no opportunity for the extensive breeding of mosquitoes. Quite recently this idea has been taken up with practical ends in view in regard to antimosquito work in German colonies in Africa. It is stated in a dispatch from Consul-General Richard Guenther, of Frankfort,? that the director of fisheries at Biebrich, Mr. Bartmann, had found a duckweed of the genus Azolla to be especially well adapted to this use; and it was at his instance that experiments were made at the malaria station at Wilhelmshaven. It was found that the growth of the plant covered the experimental waters in a short time with a layer of about 6 centimeters, which suffocated all the mosquito larve below and prevented the living insects from de- positing eggs in the water. Consul-General Guenther states that sev- eral years ago Director Bartmann communicated this method to the mosquito-destroying commission at Eltville on the Rhine, which has used it repeatedly with good success. So positive were the statements published in the United States as to the results of Mr. Bartmann’s work with Azolla plants that one species has been imported from Europe into the United States and will be experimented upon by the United States Department of Agri- culture and by Doctor Smith, of Rutgers College. The prospects of success, however, are by no means great. One of the German offi- cials who took part in the question of mosquito extermination in the German-African colonies is far from enthusiastic regarding the prac- tical use of this plant, although it has been advertised on all sides in Europe and in this country. In his opinion it may possibly be of some use in special places, but so far as experiments have gone, down to the present day, the plants will not grow in dense or even moderate shade, and therefore they are of no use in the tropical forests where — there are large and small pools of water—the very places where it is most needed. Moreover, the Azolla plants do not stand any great cold, nor do they stand short seasons, for which reasons their use is excluded from highland and northern regions. Further, they will not grow in brackish water and can not be utilized along seacoasts, and, still further, in case of drought they all perish and thus necessitate the restocking of dried pools and swamps. A short statement regarding the practical use of water plants occurs on pages 1 and 2 of the fourth volume of Theobald’s ‘‘Mono- a Monthly Consular and Trade Reports, Bur. Manufactures, U.S. Dept. Commerce and Labor, March, 1909. DETERRENT TREES AND PLANTS. 99 eraph of the Culicide of the World.” This statement may well be quoted: Major Adie, I. M.S. (Ind. Med. Gaz., xxxix, June, No. 6, 1904), brings considerable evidence to bear on the benefit of Lemna minor as a means of keeping mosquitoes from laying their eggs on water. He shows that tanks covered with this green flat weed never contain larve of Culicidz, whilst others at the same time of year are full of them. Asa test he ‘‘cleared certain areas near the banks of all Lemna and enclosed them with light floating structures, which were fixed enough to resist the winds—in fact, made experimental pools. I was pleased,’’ he says, ‘‘to find in due time plenty of Anopheles larve in these pools. ‘Thisseemed to prove that Lemna acts as a mechanical obstruction to the process of egg-laying, and a very obvious method of prevention occurred to me. Why not deliberately promote the growth of Lemna minor in all ~ unavoidable collections of water to prevent the propagation of mosquitoes?”’ This same green plant grows freely in England, and I have noticed a similar occur- rence here. A pond close to my house was frequented by numbers of the larvee of Anopheles bifurcatus and A. maculipennis every year. Two years ago its surface became smothered with Lemna minor, Linn., and Lemna arrhiza, Linn.; no Anopheline larvee could then be found. As this was the only breeding ground near, both species have practically died out. | This small yet widely distributed genus of floating plants evidently has a very marked effect upon the frequence of culicid larvee in natural and artificial collections of water. The little Lemna arrhiza, or the rootless duckweed, occurs in Asia, Africa, South America, and Europe, and apparently has the same effect as the larger L. minor. An early suggestion as to the practical use of water plants occurs in Mr. Wiliam Beutenmiiller’s essay on the “‘ Destruction of the mos- quito and house fly,” published in Dragon-Flies v. Mosquitoes, The Lamborn Prize Essays, New York, 1890. Mr. Beutenmiller states that Mr. L. P. Gratacap, of the American Museum of Natural His- tory, suggests the increase of fresh-water alge as deterring the progress of mosquito larve in the water and as affecting their destruc- tion before they can rise to the surface of the water to breathe. Mr. Beutenmiiller, considering the suggestion important, stated that he believed that the vast number of fronds of Oscillatoria in the Central Park lakes, in New York City, have had a deterrent effect on the propagation of mosquitoes in the lakes. A largely disseminated mass of alge floating through the water by its intermixed and dif- fused stipes he thought would seriously embarrass the development and movements of the mosquito larve. | _ The duckweeds were considered by Dr. H. P. Johnson in an appen- dix to Smith’s New Jersey Report for 1902,¢ and by virtue of the actual small-scale experiment tried, these observations are printed in full. While most forms of aquatic vegetation promote the breeding of mosquitoes, the Lemnacee, or duckweeds, are unfavorable, and in many waters almost or even wholly prevent it. These tiny plants consist merely of a floating frond, resembling a minia- ture lily-pad. It is circular or more frequently lobated and three to six millimeters @ Rep. Ent. Dept. N. J. Agr. Coll. Exp. Sta. f. 1902, pp. 565-566. 30 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. in diameter. From the under surface hang one or more roots, which never fasten in — the soil, but derive their nourishment from the water. Its reproduction, mainly by ° division of the frond, is so rapid that in a short time (usually before July 1) it com- pletely mantles quiet waters, notably sheltered ponds and ditches without percepti- ble flow. Its extraordinary abundance, often covering whole acres of shallow water, makes it an efficient protection from mosquito breeding. Wherever this plant forms a complete covering no larve have been found. Such places should never be treated with oil, for nature has provided a far more lasting and equally effective protection. It is probably impossible for a mosquito to lay her eggs on lemna-covered water. Even should larve wander in from adjacent waters, they would be unable to reach the surface for air, and would thus soon become asphyxiated. Larvee of Culex pun- gens, injected by means of a pipette beneath the lemnain the jar * * * died in less than an hour. Where the lemna mantle is not complete, but presents interspaces of open water, larvee of both Culex and Anopheles will usually be found in small numbers only, for lemna waters are apt to harbor the various predaceous water-bugs in great numbers. In considering these duckweeds it should be pointed out that mos- quito larve other than Anopheles are often found in waters well covered by them. Both Dr. H. G. Dyar and Mr. Frederick Knab have made this observation. SMUDGES AND FUMIGANTS. Hunters and campers have been in the habit of using almost any- thing that will make a dense smoke as a smudge to drive away mos- quitoes. In Bermuda, fresh cascarilla bark is burned for this pur- ‘pose, and elsewhere other green bark and vegetation. For household use, however, a number of different substances have been tried. / PYRETHRUM OR CHRYSANTHEMUM. For many years finely ground powders known as Pyrethrum pow- der, Chrysanthemum powder, Persian insect powder, or Dalmatian insect powder have been used to kill insects. They became famous for their insecticidal effects long before their composition was known. Their use seems to have originated in Asiatic countries beyond the Caucasus Mountains. The powder was sold at high price by the inhabitants and was brought by merchants to Russia and western European countries. The nature of the powder was kept a secret until the beginning of the last century, when an Armenian merchant, Mr. Jumtikoff, learned that the powder was obtained from the dried flowerheads of certain species of composite plants of the genus Pyre- thrum growing abundantly in the region now known as “‘Transcau- casia.”’ The son of Mr. Jumtikoff began to manufacture the article on a large scale in 1828, and since then the pyrethrum industry has steadily grown and now the export in dried flowerheads in that part of the country is very important. The species grown commercially in the Transcaucasian region is Pyrethrum roseum. The species grown in Dalmatia is P. cinerarie- SS SMUDGES AND FUMIGANTS. 31 folium, and the crop in Dalmatia is comparatively as valuable as the ‘other. Thirty years ago it was considered the most valuable export in Dalmatia. The best powders are made from the dried flower- heads of these plants, and the essential principle seems to be a vola- tile oil that disappears with age and with exposure. Powders im- ported from Europe are apparently not so strong as powders made in this country from imported dried flowerheads brought over in bulk. For this reason it was, many years ago, deemed very desira- ble to establish a Pyrethrum-growing industry in the United States, and in 1881 the United States Entomological Commission imported ~ and distributed the seeds of the two species above mentioned to a number of correspondents in different parts of the country. The total success was inconsiderable. Further experiments another year met with comparative failure. About this time more extensive plantations were made in California and an insect powder was made by the Buhach Producing and Manufacturing Company, of Stockton, Cal., which, being American grown and freshly ground, came into use, and is still being produced and sold under the proprietary name of ‘“‘buhach,”’ the word being supposedly derived from a slavonic word *“Duha,’ meaning flea. An article by Mr. D. W. Coquillett on the production and manufacture of this powder will be found in a bul- letin ¢ of this Bureau. Most of the insect powders sold in the shops in this country have Pyre- thrum powder asa basis. It is difficult to get a pure and thoroughly efficient powder. There isoften adulteration. Frequently the powder made from the dried flowerheads is adulterated with powder made from the stems, or with other adulterants. Pyrethrum powders are usually used dry and are puffed or blown into crevices frequented by insects, or puffed or blown into the air of a room in which there are mosquitoes or flies. The burning of the powder in a room at night is a common practice. The powder is heaped up in a little pyramid which is lighted at the top and burns slowly, giving off a dense and pungent smoke with an odor very much like that of the ‘Chinese punk used to light firecrackers. Often the powder is moist- ened and molded roughly into small cones, and after drying it burns readily and perhaps with less waste than does the dry powder. Of late years in mosquito-infested countries a number of mosquito pastilles have been sold, and many of these are molded from powders that contain more or less Pyrethrum. The efficacy of the burning ~pyrethrum in a close room is almost perfect. It will not actually lull all the mosquitoes, but will stupefy them and cause them to fall to the floor where they may be swept up and burned. With the windows open, however, and the constant currents of fresh air blow- ing through the room, this fumigation is not especially effective, and it is necessary for protection to sit in the cloud of smoke. @ Bul. i2, old series, Div. Ent., U. S. Dept. Agr., pp. 7-16, 1886. 82 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. The pungent odor of burning pyrethrum is not disagreeable to most people, but to some it is disagreeable, and with certain sus- ceptible individuals it produces headache. It is apparently possible, however, to volatilize the oil without producing the actual smoke. Mr. H. W. Henshaw, of the Bureau of Biological Survey, United States — Department of Agriculture, informs the writer that a few years ago aman in Hawaii patented an appliance for producing this volatiliza- tion which is all that can be wished for. The powder is placed on a brass or other metal screen above the chimney of a kerosene lamp, the idea being to dissipate the vapor of the volatile oil. According to Mr. Henshaw the effect of this method is most remarkable. “ Be- sides being very economical in powder there is only a very slight odor perceptible and that is not at all unpleasant. The effect on the mosquitoes is immediate and all that can be wished for. They simply clear out.’’ Another method of burning the powder that has often been employed by the writer consists in puffing it from an in- sufflator into a burning gas jet. This is a simple method where gas is used for illuminating purposes and produces a vapor that suffocates all mosquitoes and other insects that may be in the room. | While pyrethrum has been mainly used as a means of clearing” living rooms of mosquitoes, and has ordinarily been burned in the rooms while they were occupied, it has also come into use in the extensive fumigation of houses in cases of epidemics of yellow fever, in the effort to rid houses of malarial mosquitoes, and to destroy all mosquitoes hibernating in cellars, attics, or disused rooms of residences, as well as similar hibernating mosquitoes in barns and outhouses. While reasonably effective for such purposes, it does not seem to be as effective as some of the other substances to be mentioned later and at the same time it is more expensive. As to the quantity to be used, the regulations of the board of health of New Orleans, adopted May 25, 1903, specify the burning of 4 ounces of pyrethrum powder to 1,000 cubic feet of space; but the president of the board, Dr. Edmond Souchon, a little less than a year later wrote to the United States Marine-Hospital Service that this quan- tity was found insufficient for thorough work, and that 1 pound of the powder to every 1,000 cubic feet of space is necessary. As a matter of fact, however, the New Orleans board of health aban- doned pyrethrum about that time, on account of the fact that the fumes do not kill mosquitoes but simply stupefy them, so that they have to be brushed up and burned. Not willing to run the slightest — chance of having mosquitoes survive by escaping destruction after being stupefied, the board decided to use sulphur fumes in preference. Nevertheless, on account of the fact that the fumes are not noxious to human beings, there still remains a decided use for pyrethrum in everyday work in mosquito-inhabited regions. SMUDGES AND FUMIGANTS. ao MIMMS CULICIDE. During the yellow-fever outbreak in New Orleans in the summer ~ of 1905 a Mr. Mimms, a chemist of New Orleans, invented a mosquito fumigant which was experimented with rather extensively and found to give good results. It was made of equal parts, by weight, of carbolic-acid crystals and gum camphor. The acid crystals were melted over a gentle heat and poured slowly over the gum, resulting in the absorption of the camphor and a final clear, somewhat volatile, liquid with rather an agreeable odor. This liquid is permanent and may be kept for some time in tight jars. In fumigation work 3 ounces of this mixture is volatilized over a lamp of some kind for every 1,000 cubic feet of space. A special apparatus for the pur- pose has been perfected by Dr. H. A. Veazie, of New Orleans, but a simple apparatus may be made from a section of a stovepipe, cut so as to have three legs and outlets for draft, an alcohol lamp placed beneath and a flat-bottomed basin on top. The substance is inflammable, but the vapor is not explosive. The vapor is not dangerous to human life except when very dense, but it produces a headache if too freely breathed. The writer, on the 8th of November of the epidemic year (1905), took part in the fumigation of a room containing about 1,200 feet of space in New Orleans in company with Dr. J. H. White, in charge of the public health and marine- hospital service operations in the city during the epidemic, Dr. Rupert Blue, Doctor Richardson, Dr. H. A. Veazie, and several other assistant surgeons in the service. A number of specimens of Culex quinguefasciatus were flying about the room. There were two boxes each about 1 foot long, with gauze slides containing one-half dozen or more mosquitoes each and a large tube of 2 inches diameter and possibly 14 feet in length, the mouth of which was covered with mosquito bar and which lay on its side on the mantelpiece and contained several specimens of the Culex. About 6 ounces of the mixture were volatilized and the room was kept closed, without any -effort to artificially stop cracks, for exactly one hour. Upon re- entering and airing the room, all mosquitoes were found to be dead and a cockroach was also found dead on the floor, having come up from between the cracks. The vapor is lighter than air, and the mosquitoes in the room unnoticed on entrance soon after fumiga- tion sought the lower air strata of the room, gradually descending toward the floor and toward the windows, which were on one side of the room only. Sheets of manila paper had been spread before each window, and on these sheets at the end of the hour were all of the mosquitoes to be found in the room. An account of experiments with this mixture, containing details of apparatus, etc., by Passed Assistant Surgeon Berry, of the United 37713—Bull. 88—10——3 1 a ane Ut Bn; ‘3 34 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. States Public Health and Marine-Hospital Service, has been pub- lished.? The conclusions reached by Doctor Berry are as follows: 1. Culicide, in the proportion of 4 ounces per 1,000 cubic feet, used for two hours with apparatus similar to that used by us, kills Caer pungens, —o_ and Ano- pheles maculipennis and temporarily stuns the house fly. 2. In the proportion of 3 ounces to 1,000 cubic feet it does not alae kill the Anopheles maculipennis. 3. Culicide takes fire spontaneously if heated sufficiently. It is therefore neces- — sary to keep the liquid at a certain distance from the flame; it is also better to have more than one basin in a large space, and about 8 ounces is the maximum quantity touseinone pan. All large cracks must be pasted up—the doors and windows, if loose fitting. Gummed paper spread under a window left light would be of great benefit. (I concur with Passed Assistant Surgeon Goldberger as to the closing up of large cracks, but more for preventing weakening of the strength of the gas in the room by diffusion than from any belief that insects might escape from the room.) 4. In the minds of intelligent operators, and used according to the methods em- ployed by us, it ranks next to sulphur as an insecticide in practical fumigation. 5. Culicide vaporizes and later cools, condensing on exposed surfaces again as it cools. Whether in this way it injures articles of gilt and the like was not investigated. In practical work the only articles removed from rooms were foodstuffs and animal pets, and no complaint of injury was received. It gradually evaporates, leaving a ~ persistent, though not disagreeable, odor. As to thecost, with the present high prices of the ingredients of Culicide the cost of fumigating a room with 4 ounces to 1,000 cubic feet is 16 cents per 1,000 cubic feet, as compared with sulphur at 7 cents and pyrethrum at 50 cents, using 2 pounds of each of the latter per 1,000 cubic feet. The estimate does not take into consideration the alcohol used to evaporate the Culicide, but this is not much more, if any, than’ that used to ignite pyrethrum or sulphur pots. A further saving in favor of Culicide is that the apparatus can be easily carried in the hands from place to place. Had sulphur.been used in the instances cited a wagon would have been necessary to trans- port the materials, which were, in the case of Culicide, conveyed in street cars. The gang would have had to be larger to move the many articles from a house necessary to be removed in sulphur fumigation, to say nothing of the larger amount of pasting to — be done. Likewise, at the end of the fumigation the time required to remove the apparatus from the room is much less. For this and other reasons, if the cost of the labor is counted, I do not believe Culicide is much more expensive than sulphur, and if the cost of the articles damaged by sulphur is considered, the difference would be in favor of Culicide. PYROFUME. Dr. J. H. McCormack, of Mobile, Ala., has discovered that pyro- fume, derived by a fractional distillation from pine wood, as a by- preaiicd in the manufacture of turpentine, is a valuable an good fumigant for mosquitoes. It is a clear liquid of a straw color; has a pungent taste, and the odor of pine woods. It is said to be harmless to mucous membranes, skin, fabrics, colors, polished metal, and painted woodwork. A report of the experiments with this sub- stance by Passed Assistant Surgeon Francis of the United States Public Health and Marine-Hospital Service, has been published.° a Public Health Reports for February 2, 1906, vol. 21, No. 5, pages 83-89. b Public Health Reports, June 29, 1906, vol. 21, No. 26, pp. 711-712. SMUDGES AND FUMIGANTS. 35 A summary of Doctor Francis’s experimental work follows: 1. As compared with sulphur, pyrofume stands on an equal footing in price. 2. Whereas the federal regulations require two hours’ exposure to sulphur, pyro- fume is efficient against mosquitoes in one hour. 8. While sulphur is injurious to metals, fabrics, paint, and colors, pyrofume leaves them unchanged. 4. Pyrofume is suitable for fumigating the engine rooms and cabins of ships, and for cars and fine residences. 5. In amounts necessary to kill mosquitoes it does not injure bananas. 6. A person can walk about in a room full of fumes and can sleep without discomfort in a room two hours after fumigation. 7. It requires only five minutes to fumigate a large room of 5,000 cubic feet. 8. The fumes are generated outside the room and conducted into it. These conclusions were favorable, but the substance has not been taken up in the practical work of the Public Health Service on account of the fact that special contrivances necessary for the best application of the substance have not yet been perfected. SULPHUR DIOXID. The damage done by sulphur dioxid to household goods is the principal objection to its use as a fumigant, but in the case of yellow fever epidemics where absolutely thorough fumigation is necessary it is the most reliable of all substances to use. It was used prac- tically exclusively in the antimosquito work during the yellow-fever outbreak of 1905 in the city of New Orleans. Suspected houses were fumigated in the most thorough way. Every effort was made to close all crevices in the rooms fumigated. Heavy paper was pasted over all apertures, including cracks. This gas is obtained by burning flowers of sulphur or lump sulphur in a small pot, fire being started with alcohol. It should be used on a bright day, and pots and polished metal and delicate things should be removed. It has been found that 2 pounds of sulphur for each 1,000 cubic feet of space will be perfectly efficient against mosquitoes and other insects. Sulphur candles may be used where available.¢ Writing of sulphur, Giles objects to pure sulphur fumigation on account of the difficulty of burning it, and suggests a mixture of 1 part of niter and charcoal to 8 of sulphur, the mixture being made up in pastilles weighing 4 ounces each, by means of a little gum water, dried in the sun. In India he burned one of these pastilles for every 1,000 cubic feet of space and found that the effect was admirable, and that even in thatched buildings hardly a mosquito escaped. After fumigat- ing, the floor of a bathroom in which hardly any mosquitoes could be found was covered with dead mosquitoes, which indicates not only @ For an excellent account of certain careful experimentation with sulphur, see an article by Passed Assistant Surgeon Francis, of the United States Public Health and Marine-Hospital Service, published in Public Health Reports, March 29, 1907, vol. 22, No. 13, pp. 346-348. 36 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. the efficacy of the fumigant, but also the effectual ways in which the Indian mosquitoes hide. He suggests that the fumigating should be done toward the end of the hibernating season, and during the heat of the day, when practically all of the mosquitoes are under shelter. He urges the adoption of this method of fumigation in all government barracks, showing that each pastille costs no more than one Lee- Medford cartridge, and that the annual bill for invaliding men who have been educated to use the latter is so heavy that it would be well to adopt any measure likely to diminish it. In. the course of the admirable work carried on during the last six years in Rio de Janeiro and which has achieved such brilliant results, it has been found that sulphur dioxid has given the best results in the disinfection of houses. Cruz has given the following account of the methods used: The house to be disinfected was completely closed. Every opening or orifice where gas might escape was sealed with gummed paper. The furniture, too, after being thoroughly cleansed, is tightly closed. Metallic or gilded objects are protected with a covering of vaseline. After the roof is covered over with canvas the garrets are opened for the free access of sulphur gas. The canvas is fastened to the walls with lath. Then sulphur is burned in proportion of 10 to 20 grams per cubic meter, being deposited in several receptacles distributed about the house and kept clear of the floor. Each receptacle should not contain more than 1 kilogram [2.2 pounds] in order to insure complete combustion. In the vacant spaces under the roof the burning sulphur should be placed in receptacles set into others containing water toavoid danger of fire. After - all the receptacles are placed, the workmen close up the only exit left open and‘ keep the house thus sealed for not less than 2 hours. The heated air and that displaced by the sulphur gas escapes through the crevices of the roof, but the mosquitoes are kept in by the canvas covering. | In the admirable fight against the yellow-fever mosquito in New Orleans in the summer of 1905, the following directions for fumigating with sulphur dioxid were given out by the health authorities: Remove all ornaments of metal, such as brass, copper, silver, and gilt from the room that is to be fumigated. All objects of a metallic nature which can not be removed can be protected by covering the objects tightly with paper, or with a thin coating of vaseline applied with a brush. Remove from the room to be fumigated all fabric material after thoroughly shaking. Open all drawers and doors of furniture and closets. The room should be closed and made as tight as possible by aeons all openings in chimney, floor, walls, keyholes, and cracks near windows and doors. Crevices can be closed by pasting strips of paper (old newspapers) over them with a paste made of flour. The sulphur should be placed in an iron pot, flat skillet preferred, and this placed on bricks in a tub or other convenient water receptacle with about an inch of water in the bottom. This is a precaution which must be taken to guard against accidents, as the sulphur is liable to boil over and set fire to the house. The sulphur is readily ignited by sprinkling alcohol over it and lighting it. The apartment should be kept closed for two hours, and then sar up and well ventilated. Note.—To find the cubic contents of fie room, multiply the i stieth of the room by the width, and this total by the height, and to find the amount of sulphur necessary to sa ee ee SMUDGES AND FUMIGANTS. 37 fumigate the room divide the cubic contents by 500, and the result will be the amount of sulphur required in pounds. Take, for example, a room 15 feet long, 10 feet wide, and 10 feet high, we would multiply 15 x 10 x 10, equals 1,500 cubic feet. Divide this by 500 and you will have the amount of sulphur required, viz, 3 pounds. After a rigid series of experimental tests, Rosenau, of the U.S. Public Health and Marine-Hospital Service, concludes that sulphur dioxid is unexcelled as an insecticide. He shows that very dilute atmos- pheres of the gas will quickly kill mosquitoes, and that it is quite as efficacious when dry as when moist. He shows that it has surprising power of penetrating through clothing and fabrics, and that it will kill mosquitoes even when hidden under four layers of toweling in one hour’s time and with very dilute proportions. He states that although this substance has long been disparaged as a disinfectant, because it fails to kill spores, it must now be considered as holding the first rank in disinfection against yellow fever, malaria, filariasis, and other insect-borne diseases. OTHER FUMIGANTS. In the early antimosquito work in European cities different sub- stances were experimented with. Fermi and Lumbao in their out- lined experiments recommend chlorin gas. These writers advise that 4 or 5 spoonfuls of chlorid of lime be placed in a dinner plate and that from 5 to 10 cubic centimeters of crude sulphuric acid be poured upon it. This liberates the chlorin gas, which kills the mosquitoes. The same writers claim that the vapors of chloral act rapidly, killing mos- quitoes in a few seconds. Celli and Casagrande in their early experi- ments in Italy recommend a substance called larycith III, which is probably a misprint for larvacide. This is dinitrocresol, a yellow aniline color, which kills adult mosquitoes when burned in small quan- tities. Formaldehyde gas was recommended in 1890, but has been found to have almost no insecticidal value. Dr. John B. Smith? found that the powdered ‘‘jimson’’ weed (Da- tura stramoniwum) can be burned to advantage in houses. He recom- mends 8 ounces to fumigate 1,000 cubic feet of space. He states that it should be made up by the druggist into an amount with niter or saltpeter 1 part to 3 parts of Datura, so as to burn more freely. He states that the fumes are not poisonous to human beings, are not injurious to fabrics or to metals, and can be used with entire safety. _ He suggests that it be burned in a tin pan or on ashovel. A long list of fumigants is given by Celli in his work entitled ‘“‘Malaria According to the New Researches,’ and this list has received a critical review, which carries at the same time the results of certain experimental work by Arthur J. Kendall, in Bulletin No. 1 of the 2 Bul. 216, N. J. Agr. Exp. Sta., p. 12, November 24, 1908. 38 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. laboratory of the board of health, Isthmian Canal Commission, Panama, 1906. Bulletin No. 2 of the same service (1906) contains an account of experiments in practical culicidal fumigation, also “od Doctor Kendall. The burning of dried orange peel has been recommended as a aes. rent against mosquitoes, but there seem to be no records of conclusive experiments, although the writer has been assured of its efficacy by a Japanese physician visiting the United States. In the course of his experiments with different disinfectants against mosquitoes, Rosenau, of the U.S. Public Health and Marine-Hospital Service,? did his principal work with formaldehyde and sulphur dioxid. We have mentioned his conclusions with regard to the latter substance in a previous paragraph. Formaldehyde gas, on account of its ger- micidal use, was early suggested against mosquitoes when their importance in the réle of carriers of disease was ascertained, so that exact experimentation was necessary. Rosenau’s results were as follows: Formaldehyde gas is a feeble insecticide. Mosquitoes may live in a very weak atmosphere of the gas overnight. It will kill them, however, if it is brought in direct contact in the strength and time prescribed for bacterial disinfection. For this pur- pose any of the accepted methods for evolving the gas is applicable, but the methods which liberate a large volume in a short time are more certain than the slower ones. Direct contact between the insects and the gas is much more difficult to obtain in ordinary room disinfection against mosquitoes than against germs, because the sense of self-protection helps the former to escape from the effects of the irritating gas. They hide in the folds of towels, bedding, clothing, hangings, fabrics, and out of the way places, where the formaldehyde gas does not penetrate in sufficient strength to kill them. The gas is polymerized and deposited as paraform in the meshes of fabrics, which prevents its penetration, and large quantities are lost by being absorbed by the organic matter of fabrics, especially woolens. In our tests whenever the insects were given favorable hiding places, such as incrumpled paper or in toweling, they quickly took advantage of the best place for themselves and thus escaped destruction. There is a striking analogy between the strength of the gas and the time of exposure necessary to penetrate the fabrics in order to kill mosquitoes and the strength and pune necessary to penetrate in order to kill the spores of bacteria. Mosquitoes have a lively instinct in finding cracks or chinks where fresh air may be entering the room, or where the gas is so diluted that they escape destruction. They are able to escape through incredibly small openings. Some of the smaller varieties, such as the Stegomyia fasciata can get through a wire screen having 12 meshes to the inch. Therefore, formaldehyde gas can not be trusted to kill all the mosquitoes in a room which can not be tightly sealed. It was concluded that to succeed in killing all the mosquitoes in a closed space with formaldehyde gas the following definite requirements are essential: A very large volume of the gas must be liberated quickly, so that it may diffuse to all portions of | the space in sufficient concentration. The room must have all the cracks and chinks where the insects may breathe the fresh air carefully sealed by pasting strips of paper over them. The room must not contain heavy folds of drapery, clothing, bedding, or fabrics in heaps or so disposed that the insects may hide away ra the full effects of this gas. a Bul. No. 6 of the Hygienic Laboratory, September, 1901. ~ ee SMUDGES AND FUMIGANTS. 39 MERCURIC CHLORID. Surg. G. M. Guiteras,? of the United States Public Health and Marine-Hospital Service, has recounted a series of experiments with mercuric chlorid, the use of which was first suggested to him by G. F. Matzke, steward on the American steamer Beecham, who told Doctor Guiteras that he had used it in the cabin of his vessel with success. Doctor Guiteras carried out a series of five experiments in a room 12 feet high by 15 feet by 134 feet, having a capacity of 2,385 cubic feet, sublimating the mercuric chlorid in a porcelain evaporating dish over an alcohol lamp. Mosquitoes in cages approximately con- taining a cubic foot of space, covered with wire gauze, were exposed at varying elevations in the room, and from 30 to 60 grams of mercuric chlorid were sublimated at exposures varying from two to three hours, at temperatures of from 77° to 88° F. Mosquitoes in the upper part of the room were invariably killed, while some of those very near the floor escaped, most of the latter, however, being killed, and the remainder never recovering perfectly except in one experiment where the temperature was only 77° F. Twenty-five grams of _ mercuric chlorid were found to be sufficient for 1,000 cubic feet of space. He showed that about twenty minutes are consumed in sub- limating 60 grams of the chlorid; that brass work is not tarnished, and that nickel-plated work and instruments are not tarnished when wiped off immediately after fumigation. He further showed that painted surfaces are unaffected unless the chlorid is sublimated close to them and they are not immediately wiped off. Moreover, it does not affect colored silk, cotton, or woolen goods. The poisonous quali- ties of the substance, in Guiteras’s opinion, do not constitute a real danger. When the room was opened after the experiments, he found it filled with a thick mist, but the room was entered without any especial precaution and the windows were opened. In a few minutes the vapor was carried away, leaving a slight deposit on the surfaces within the room. ‘This was allowed to remain for two or three days, and the room was used in the meantime without any bad results. The deposit, however, should have been removed with a damp cloth, and with this ordinary care, the experimenter believes, there will be no danger in the use of the substance. The advantages he considers to be the facility of obtaining mercuric chlorid, the small quantity necessary, and the simplicity of its use; _ a good alcohol lamp and a porcelain evaporating dish constitute all the machinery necessary, and its use is certainly much more con- venient than sulphur, where the operators have to carry about heavy iron pots and barrels of sulphur. As to expense, he shows that at $1 per pound the 25 grams used per 1,000 feet cost somewhat less than @ Public Health Reports, vol. 26, No. 50, pp. 1859-1861, December 10, 1909. 40 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. i half a cent, whereas 2 pounds of sulphur per 1,000 cubic feet would cost 6 cents. Moreover, it is pointed out that in practical work on a large scale the expense and trouble of hauling the disinfecting equip- ment from one place to another would be greatly diminished. He concludes that while mercuric chlorid can not altogether take the place of sulphur, it has a hitherto unrecognized effect, especially with reference to flies and mosquitoes.. APPARATUS FOR CATCHING ADULT MOSQUITOES. ; In his important paper entitled ‘‘A Preliminary Account of the Biting Flies of India,’’?* Mr. H. Maxwell-Lefroy, imperial entomolo- gist, describes an interesting apparatus which he used to catch mos- quitoes in his bungalow. In an account published in the United States Daily Consular and Trade Reports,? Consul-General William H. Michael, of Calcutta, mentions this apparatus, stating it to be an invention of Mr. Lefroy. In his own account, however, Mr. Lefroy does not claim it as his invention. . He used a wooden box, lined with dark green baize and having a hinged door; the trap was 12 inches long, 12 inches broad, and 9 inches deep; a small hole, covered by a revolving piece of wood or metal, was prepared in the top of the box, and tin was placed on the floor inside. Owing to the habits of mosquitoes to seek a cool, shady place in which to rest, such as a dark corner of the room, or bookshelf, or something of the sort, they will enter this trap, which is put in the part of the room most frequented by mosquitoes, all other dark places being rendered uninhabitable, so far as possible. Mr. Lefroy writes: My room being open to the veranda, hordes of mosquitoes come in, and as the room is lined with bookshelves there are many desirable sleeping places. The trap stands in a shady corner, and a large number of mosquitoes enter it when they come home in the morning; the rest are usually driven out of the bookshelves either with a duster or a little tobacco smoke. Finding this desirable sleeping place untouched, they go in; the door is then slammed and fastened. At the top of the box is a small hole with a movable plate to close it; through this a teaspoonful or less of benzene is intro- duced and the plate put back. After a little time all the mosquitoes are dead. The box is taken to the veranda and opened there till the fumes of benzene escape. In this way in thirty days Mr. Lefroy caught 2,336 mosquitoes—a daily average of 83.75; daily average of females, 22.68. At the same time 23 of the biting sand flies of the genus Ceratopogon were caught. He further states that whereas the inmates were before disturbed with mosquitoes and sand flies, which especially attacked the baby, the pest practically entirely ceased. All of the mosquitoes were not exterminated, but so large a portion was a Bul. No. 7, Agricultural Research Institute, Pusa, India, pp. 12-14, 1907. b Dept. Commerce and Labor, Bureau of Manufactures, p. 10, March 3, 1909. Ks, REMEDIES FOR MOSQUITO BITES. Al destroyed that the inmates of the house suffered no more. Mr. Lefroy goes on to say: I am not prepared to recommend this as a universal remedy. It must be sensibly used; a small amount of personal effort in teaching a servant is necessary at first. But where mosquitoes are a plague, especially to little children, the housekeeper’s thirst for the blood of the mosquitoes may rise to so great a pitch that she will welcome this device and take a delight (as we do) in counting the corpses daily. An interesting homemade apparatus in common use in many parts of the United States is very convenient and effective. It consists of a tin cup or of a can cover nailed to the end of a long stick in such a way that a spoonful or so of kerosene can be placed in the cup, _ which may then, by means of the stick, be pressed up to the ceiling so as to inclose one mosquito after another. When pressed up in this way the captured mosquito will attempt to fly and be caught in the kerosene. By this method perhaps the majority of the mos- quitoes in a given bedroom—certainly all those resting on the ceiling— can be caught before one goes to bed. REMEDIES FOR MOSQUITO BITES. It must have been the experience of most people that ordinarily little swelling and irritation result from the puncture of a mosquito where there has been no scratching or rubbing of the part. But individuals vary greatly in this respect, and it is undoubtedly true that not only do different species of mosquitoes vary in their effect, but that different individuals of the same species may also vary. The application of household ammonia has been found by many to give relief, and alcohol is also said to stop the irritation. Dr. E. O. Peck, of Morristown, N. J., finds glycerin a sovereign remedy. Touch the bite with glycerin and in a few minutes the pain is gone. Dr. Charles A. Nash, of New York City, marks the puncture with a lump of indigo and states that this instaritly stops the irritation, no matter whether the application is made immediately or after the lapse of a day or so. The most satisfactory remedy known to the writer from his own personal experience has been moist soap. Wet the end of a piece of ordinary toilet soap and rub it gently on the puncture and speedily the irritation will pass away. Mr. Charles Stevenson, of Montreal, writing to the Canadian Entomologist in September, 1901, stated that he had found naphthaline moth balls to afford immediate relief from the bites of dangerous Diptera, including mosquitoes, and that a friend of his had used it successfully on flea-bites. He advises rubbing the moth ball on the affected part for a few minutes. Napth- thaline is also recommended by Professor Boges, director of the na- tional board of health at Buenos Aires. odin is frequently recommended for this purpose, and a note in a recent number of the Journal of Tropical Medicine and Hygiene 42 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES, recommends a modification in the shape of 30 to 40 grains of iodin to the ounce of saponated petroleum, stating, ‘‘A few drops rubbed in a mosquito bite or wasp sting allay the pain instantaneously.” Rey. R. W. Anderson, rector > St. Thomas and St. Dennis, wrote us from Wando, 5S. C., some years ago, that he has often eae that by holding his bead to a hot lamp chimney the irritation of pesiiti gh punctures would be instantly relieved. DRAINAGE MEASURES. The drainage of swamp areas for agricultural or other industrial reasons needs no argument nor treatment here. The value of re- claimed swamp land for various purposes is treated somewhat in extenso in a later section, ‘‘Value of reclaimed land.” The drain- age of swamp areas, primarily in order to improve sanitary condi- tions and to reduce the annoying scourge of mosquitoes, which in itself frequently prevents the proper development of neighboring regions, is in operation and needs no argument; but it is, neverthe- less, of recent undertaking. Thus, in drainage a number of things are accomplished, and where drainage is accompanied by filling, still other results are to be reached. Drainage on a small scale for the _ purpose of doing away with mosquitoes has been practiced for a long time: In ‘‘Mosquitoes,” page 198, the writer shows how, by an ex- penditure of $40 for drainage in the summer of 1900 in a Maryland village, malaria practically ceased to exist, although the previous summer there had been one or more cases in every family in. the district. One of the editors of the Scientific American, Mr. Frederick K. Beech, is quoted (loc. cit., pp. 208-209) as follows: In the town of Stratford, Conn., where I have resided for the past forty-five years, we have been greatly plagued by swarms of mosquitoes, so great, in fact, that the “Stratford mosquito” became a well-known characteristic of Stratford. We have in the southern part of our town, bordering on the sound, several acres of marsh land or meadow, which would become periodically overflowed with water in the summer and a tremendous breeding ground for mosquitoes, and this plague to the town con- tinued until about 1890-91, when a party from Bridgeport, Conn., purchased a large section of the meadows and began to protect them by a dike, both on the north and south ends, which shut out the water. In addition to this, numerous drain ditches were made which helped to carry the water away. The result of this work made the land perfectly dry and spongy, so that after a rain no pools collected on the sur- face of the meadow and the creation of the mosquitoes was prevented. The trans- formation was so remarkable that people outside the town would hardly believe that it had been effected, and a year or two later the town voted a special appro- priation of $2,000 to the party who undertook to build the dike and render the meadows mosquito-proof. It had also the effect of placing on the market a large tract of land elevated from the sound, for residences, and as many as twenty-five summer residences have been built upon this land bordering on the sound, and the number is increasing each year. They are free from mosquitoes, so that the opera- tion shows the economy and the benefit that will result by using some means for eliminating the mosquito-breeding pools. Sees sarees, ee ne ae DRAINAGE MEASURES. 43 A great deal of valuable drainage work has been done in the past few years in the salt marshes of the North Atlantic coast, and there is one instance of this on the Pacific coast, with the direct idea of doing away with the salt-marsh mosquitoes, several species of which occur in such localities, all having unusual power of flight and being able to proceed inland for many miles, thus annoying the inhabitants of a large extent of country. One of the first operations of this kind was conducted by the wealthy owners of Center Island, off the north coast of Long Island, in Long Island Sound. This work led to the somewhat elaborate work under the organization known as the North Shore Improvement Association, referred to elsewhere, which included simple operations over a considerable distance along the north shore of Long Island and in the vicinity of Oyster Bay. These operations took place in 1902 and 1903. Later some excellent work was done at Lawrence, Long Island, and the following account, taken from the ‘‘Report of the New York State Entomologist,” Dr. E. P. - Felt, for 1905, gives an excellent idea of methods and results: A most striking illustration of this work is that given by Lawrence, L. I., which has amply demonstrated the feasibility of controlling the salt-marsh mosquitoes by rela- tively simple and comparatively inexpensive ditching operations. The annual expense is only about $1,000 and the total expenditure on these operations during the _ past four years does not exceed $10,000, in spite of the fact that the village is situated upon a narrow neck of land with the extensive salt-marsh areas of Jamaica Bay to the north and west and large marshes south and east, all producing in former days millions of mosquitoes, which invaded the village in swarms with every favorable breeze. Some of these marshes extend almost to the center of the village, which is so completely surrounded that a journey of 24 miles in almost any direction will bring one to a salt marsh. More unfavorable conditions for mosquito control could hardly be found, and before this work was attempted mosquitoes swarmed in the village in May and remained in numbers most of the season. The second year swarms did not invade this territory till June, and last year it was the first of July before they appeared. Our investigations at the end of last July showed that there were practically no mosquitoes in the center of the village. It was our privilege to sit on a piazza one evening when conditions were most favorable for mosquito activity. Though it was cloudy with only a little breeze, and rather warm, not one appeared. Previous to this antimosquito work it was said that one could not sit on this piazza without being covered with netting, and the owner even went to the trouble of making a framework to hold netting to suspend over individual chairs, so that his family and guests could sit in comfort. This very desirable result has been brought about by a draining system so planned that the entire length of all the ditches will be flushed by every tide. The general practice is to run these ditches within about 200 feet of firm ground and sometimes closer, making them 18 to 24 inches in width, from 2 to 3 feet deep, with main ditches here and there to tidal channels. A few headland ditches are run into the more dangerous swampy areas in baylike extensions of the marsh. Such ditches require no surveying and cost only 14 cents a running foot. A little experience enables one to lay them out properly and the tides make the determining of levels extremely easy. It was very interesting to compare the conditions between ditched areas and undrained marshes. The former were so free from mosquitoes that one could tramp upon them with practical immunity from bites, though occasionally a few mosquitoes were seen on one’s person. No larvee were found, and in fact there were very few places where 44 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. breeding was possible. Undrained marshes presented a very different condition. Mosquitoes swarming in adjacent woodlands made driving very uncomfortable, and when on the marshes one was attended by considerable swarms of vicious biters, even in midday. Here and there breeding pools were literally black with young wrigglers. This contrast between drained and undrained areas would doubtless have been much ereater were it not for the fact that our inspection was made during such a dry time that even undrained marshes presented comparatively few favorable breeding places. Experience at Lawrence has shown that deep ditches with perpendicular sides are far more permanent than shallow ones with sloping sides. The attempt to slope the bottom of the ditch so that all the water will drain out invariably results in depressions which may become dangerous breeding places and the drainage value of the ditch is much lessened. Sloping sides afford opportunity for the growth of grass and sedges with the result that the ditch soon becomes choked with vegetation. The deep per- pendicular ditches described above remain entirely free from vegetable growth, and with a little care in removing sods and drifting matter will last for years. Some dug four years ago were in perfect condition last July, though the grass growing along the sides overhung and almost hid the ditch from view in places. An area of 25 feet on each side is easily drained by such a ditch. The village now has 40 miles of marsh drains, which require more or less attention from three men during most of the open season. They keep the ditches clear, supplementing their work by judicious oiling here and there wherever mosquito larve are abundant, and then have considerable time available for perfecting the system and ditching more distant marshes. Experi- ence showed that a considerable number of salt-marsh mosquitoes bred on that portion of Jamaica Bay northwest of the village were brought in by southwest followed by northeast winds. This led to the extension of ditching operations some 2 miles beyond the village limits. The work in the immediate vicinity of Lawrence was done partly . at public expense assisted by contributions from owners benefited, though it was impossible to secure the cooperation of persons owning the distant marshes, which latter were drained entirely at village expense. The existence of such breeding areas is an imposition upon adjacent communities, and it is only a question of time before public opinion will demand a law either compelling owners to abate such nuisances or else provide for their suppression at public expense. The money invested by Lawrence in this work, a total of less than $10,000, has amply justified itselfin vastly improved conditions. The village and its vicinity have been entirely freed from breeding places, although it is subject to late summer invasions by hordes of mosquitoes when favorable winds bring them from undrained marshes. Even this will be obviated when the value of the work becomes more generally appreciated, and then the cost of the operations will be amply returned in increased land values, to say nothing of the satisfaction accruing from the absence of these dangerous and annoying pests. On the north shore of Long Island, in Connecticut, and especially in the vicinity of New Haven, certain simple ditching operations have been carried on which have resulted, at a comparative inexpense, in a very considerable reduction of the mosquito supply. THE CALIFORNIA WORK. In California, in connection with work carried on by the California State Agricultural Experiment Station, in 1905, some excellent work was done under the auspices of the Burlingame Improvement Club, in San Francisco, under the direction of H. J. Quayle, of the California Experiment Station. The territory involved is included in the upper portion of the San Francisco Peninsula, extending from South San | ee oo DRAINAGE MEASURES. 45 Francisco on the north to San Mateo on the south, a distance of about 10 miles. The salt-marsh area included consisted of a narrow strip along the San Francisco Bay shore, varying from one-half to 2 miles in width and 10 mileslong. No part of the area was continually covered with water, and it is all above the lowest high tide. The higher tides, however, particularly those accompanying full moon, almost completely submerge the area. The operations, as described ,* are quoted as follows: What was done on the marsh.—The actual work of control was commenced February 27, when a gang of men was started to work at ditching on the salt marsh. This work was started near the Blackhawk dairy, where the marshes begin north of Burlingame, it being the intention to work northward toward San Bruno, and make the work permanent as far as we would be able to go in a single season. However, the work went rapidly and the troublesome areas north of Millbrae were not so numerous as was figured, and consequently practically the whole area was covered during the past season. The ditching in the Blackhawk area consisted in connecting the pools and areas of standing water with the tidal creeks in order that they might drain more rapidly and before a brood of mosquitoes would have time to develop. The largest of these ditches were 12 inches wide and about 15 inches deep, and these served as main channels into which smaller laterals were cut. These laterals, and, indeed, the greater part of all of the ditches, were but one spade wide, and one or two spades deep, according to the depth of the pool to be drained. Only where the pools were very large and a great quantity of water to run off in a short time was it necessary to make larger ditches. By ‘‘a spade” here is meant the common California spade, which is about 6 inches wide and 10 inches high. The eastern drain spade has not yet found its way to California; - undoubtedly it would be preferable for the deeper ditches in this kind of work. In addition to the well-defined pools, there was a considerable area in the Blackhawk region which was covered with but a few inches of water for a considerable time after each high tide, and before the rains ceased in the spring water stood over this area almost continuously. Such areas had to be treated by making a number of parallel ditches from 50 to 75 feet apart, in order to permit of sufficiently rapid drainage. Rather extensive ditching was done here to make the area safe while the rains were still continuing, while later in the season, when the rains ceased, it would have been safe with much less ditching. Small pools that were far from tidal creeks were made safe by filling in rather than draining. The size of the pool, and the length of ditch necessary to drain, will determine which of the methods is to be followed. In this way the marsh area was gone over, doing away with all the places where larvee were found or were likely to be found for a distance of about a mile along the bay northward, where the diked area was met with. This part of the marsh presented a more difficult problem. The dike, having been neglected for ten or twelve years, was in poor condition, and there were several breaks in the upper end near Millbrae. The gates were not in working order, and their floors were too high to drain the area enclosed. The breaks in the dike at the upper end permitted the water to back up at the op- posite side, and this, together with the fresh water from the hills, kept the water level, at almost high tide, over a large part of the area. To make matters worse, the dike, just after it was built, was in effective operation just long enough to thoroughly dry the ’ ground and cause it to crack. These cracks, which are 4 or 5 inches wide and 2 or 3 feet deep, still exist, forming a complete network over most of the area. Mosquitoes were found breeding in this area, and it was next to impossible to get over the ground, 2 Bul. 178, Univ. of Cal. Exp. Sta., pp. 15-21, 1906. 46 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES, even with waders. A considerable part of the area was submerged to the depth of a foot or more, thus concealing from view the cracks and tidal creeks, which one was - likely to fall into at every step, and which made any attempt at rapid progress some- what discouraging. It was at once evident, under these conditions, that if the area was to be controlled, the dike must be either cut through in a number of places in order to allow a freer circulation of water, or the breaks must be repaired and the gates put in operation, and the water keptout. The latter scheme was the one followed, because it would be possible to make the area thoroughly dry, and thus the results would be more certain. In attempting to operate the gates we were made to appreciate the effect of a ten or twelve years’ coating of rust on the large screws by which the gates were manipulated. After the gates were put in operation the breaks in the dike were repaired and the weak places strengthened. The largest break repaired was immediately joining the upper gate. This was 30 feet wide, and by the action of the water had worn down so that at high tide there was a depth of 10 feet of water. A double wall of sheet piling about 6 feet apart was sunk here and the space between filled in with earth. The other breaks were repaired by sinking a single wall of sheet piling in the center and filling in on both sides with dirt. After these repairs were completed the gates were operated, opened at low tide aad closed at high tide, for a week, but at the end of this time there was still much water in the area, because the gate floors were not low enough to lower the water level suffi- ciently. This made it necessary to lower the gate floors and add an extension to the gates to reach the lower level. This being done the gates were again operated for several days, but it was found that, due to seepage of water through the dike in many places, hand operating would have to be kept up almost indefinitely. It was therefore necessary to replace these old-style gates, operated by hand, by automatic ones, and these were, consequently, put in at both the upper and lower gates, and the floors lowered 32 and 20 inches, respectively. These gates were made to swing on an axle at the top, the lower end being free and easily moved by the pressure of the water, so that at low tide it was opened by the pressure of water on the inside, and closed as the water from the high tide rose on the outside. This tidal creek, which served as an outlet for the lower gate, had become filled in to a depth of 2 or 3 feet during the period the gate was closed, and this was cleaned out for 300 or 400 yards toward the bay in order to drain out the area enclosed by the dike. With this work done upon the dike the area enclosed by it was treated in much the same way as that outside, except that the network of cracks, already mentioned, had to be filled in in many places, and several of the tidal creeks deepened. The pe for all this work came later in the season when the area was changed from a veritable breeding ground to the safest portion of the marsh. Indeed, this area was the key to the situation, and the excessive abundance of mosquitoes in this particular territory was without doubt due to this extensive breeding ground. It is appropriate to mention here the connection of this work with the reclamation of marsh lands. This tract of 500 or 600 acres, which had been useful only for duck hunting, is now thoroughly dry and could be put to agricultural uses at very little additional expense. Such work has already been extensively taken up on the marshes below San Mateo, and it had been found that a good crop of grain can be raised on such land in the second year of its cultivation. It is safe to predict that all the marsh land involved in the present campaign will be under cultivation before many years, and because of its proximity to the metropolis of the coast should be very valuable. Besides the marshes already mentioned, permanent control.work was done on the marsh about Millbrae and northward to San Bruno, and also some drainage work at Coyote Point, opposite San Mateo. The work at these places was much the same as that already described, and further details are unnecessary. ] Oe - DRAINAGE MEASURES. 4” In addition to this permanent work, there was some oiling done on the marsh where the ditching and filling work were not rapid enough to keep ahead of a developing brood. The total amount of oil applied, however, did not exceed 400 gallons, and most of this was applied to the large tidal creeks in the reclaimed land opposite San Mateo. The remainder was applied to pools where wrigglers appeared after a high tide, and, the brood being checked, we had until the next high tide in which to make the poois permanently safe. _ During 1908, 200 acres of salt-meadow land on the shore of Little’ Neck Bay, between Bay City and Douglaston, Long Island, were drained by simple ditching measures. This work was done at the instigation of the Bay Side Park Association and the Douglaston Civic Association, both associations forming a joint committee to exterminate mosquitoes. They went to the board of health of Flush- ing and enlisted its aid under a new law which permits the board of health to enforce the drainage of mosquito-breeding places. The board of health issued its orders to the owners of the meadow lands, commanding them to drain their properties within ten days. The movement was most successful, and by October 24, 1908, 75 miles of ditches had been dug on the Flushing meadows, and the work was still going on. As early as 1900 excellent antimosquito work was done on Staten Island, New York, by the Richmond County Club, under the leader- ship of Mr. W. C. Kerr, in the course of which considerable drainage of fresh-water swamps above the seacoast places was carried on-with ereat success and at a minimum of expense. This work, accom- panied with the use of kerosene on the larger ditches, resulted in complete relief from the attacks of the fresh-water mosquitoes, which during the early summer had previously been always numerous and ferocious. But, down the bluffs, below the cliffs, there was a large area of salt marsh, and in the higher portions of this marsh land the salt-marsh mosquitoes bred abundantly and flew up the bluff in swarms to take the place of the fresh-water mosquitoes. An at- tempt was made, by members of the club, to buy this land and drain it, but they were unsuccessful. A few years later the meadow was taken up by Doctor Doty, the health officer of New York, who even- tually began drainage measures, which have been carried out with persistence and effect. Some of the most effective of any drainage work has been done in the course of these operations. THE. NEW JERSEY WORK. The most interesting and probably the most important work of this character that has been done anywhere in the world was perhaps that undertaken by the State of New Jersey. The writer, in an address on ‘‘The Recent Progress and Present Conditions of Economic 48 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Entomology,” delivered before the Seventh International Zoological Congress, Boston, August, 1907, made the following statement: But the work done by Smith, in New Jersey, and that which he has under way in his large-scale campaign against the mosquitoes of that State, are of such a unique character that they force special mention. The mosquito destruction measures car- ried on by English workers, and especially by those connected with the Liverpool School of Tropical Medicine, in different parts of the Tropics controlled by England, have been large-scale work of great value. That done by the army of occupation in ~ Cuba was of enormous value, so far as the city of Havana was concerned, and an assistant just returned from the Isthmian Canal Zone assures me that it is possible to now sit out-of-doors of an evening upon an unprotected veranda anywhere in the Zone without being annoyed by mosquitoes, and without danger of contracting malaria or yellow fever. These are all great pieces of work, but when we consider the condition that exists in the State of New Jersey, and the indefatigable and successful work of Smith in the handling of the most difficult problem of the species that breed in the salt marshes, and of his persistent and finally successful efforts to induce the state legislature of that wealthy but extremely economical State to appropriate a large sum of money to relieve New Jersey from its characteristically traditional pest—we must hold up our hands in admiration. Chapter 134, of the Laws of 1906 for New Jersey, which went into effect on November 1, 1906, the passage of which was largely due to the efforts of Doctor Smith, is so interesting and important in this connection that it is quoted in full, to wit: AN ACT to provide for locating and abolishing mosquito-breeding salt-marsh areas within the State, for assistance in dealing with certain inland breeding places, and appronne money to carry its pro- visions into effect. Be it enacted by the senate and general assembly of the State of New Jersey: 1.—It shall be the duty of the director of the state experiment station, by himself or through an executive officer to be appointed by him to carry out the provisions of this act, to survey or cause to be surveyed all the salt-marsh areas within the State, in such order as he may deem desirable, and to such extent as he may deem necessary, and he shall prepare or cause to be prepared a map of each section as surveyed, and shall indicate thereon all the mosquito-breeding places found on every such area, together with a memorandum of the method to be adopted in dealing with such mosquito-breeding places and the probable cost of abolishing the same. 2.—It shall be the further duty of said director, in the manner above described, to survey, at the request of the board of health of any city, town, township, borough, or village within the State, to such extent as may be necessary, any fresh-water swamp or other territory suspected of breeding malarial or other mosquitoes, within the juris- diction of such board, and he shall prepare a map of such suspected area, locating upon it such mosquito-breeding places as may be discovered, and shall report upon the same as hereinafter provided in section eight of this act. Requests as herein- before provided for in this section may be made by any board of health within the State, upon its own motion, and must be made upon the petition, in writing, of ten or ae freeholders re btifine within the jurisdiction of any such board. — Whenever, in the course of a survey made as prescribed in section one of this act, aH is Sioned that within the limits of any city, town, borough, or village there exists — points or places where salt-marsh mosquitoes breed, it shall be the duty of the director aforesaid, through his executive officer, to notify, in writing, by personal service upon some officer, or member thereof, the board of health within whose jurisdiction such breeding points or places occur, of the extent and location of such breeding * . ee OEP aN itp ltt DRAINAGE MEASURES. 49 places, and such notice shall be accompanied by a copy of the map prepared as pre- scribed in section one, and of the memorandum stating the character of the work to be done and its probable cost, also therein provided for. It shall thereupon become the duty of the said board, within twenty days from the time at which notice is served as aforesaid, to investigate the ownership, so far as ascertainable, of the territory on which the breeding places occur, and to notify the owner or owners of such lands, if they can be found or ascertained, in such manner as other notices of such boards are served, of the facts set out in the communication from the director, and of the further fact that, under chapter sixty-eight of the laws of one thousand eight hundred and eighty- seven, as amended in chapter one hundred and nineteen of the laws of one thousand nine hundred and four, any water in which mosquito larve breed is a nuisance and subject to abatement as such. Said notice shall further contain an order that the nui- -sance, consisting of mosquito-breeding pools, be abated within a period to be stated, and which shall not be more than sixty days from the date of said notice, failing which the board would proceed to abate, in accordance with the act and its amendments above cited. 4.—In case any owner of salt-marsh lands on which mosquito-breeding places occur and upon whom notice has been served as above set out, fails or neglects to comply with the order of the board within the time limited therein, it shall be the duty of said board to proceed to abate under the powers given in sections thirteen and fourteen of the act and its amendments cited in the preceding section, or, in case this is deemed inexpedient, it shall certify to the common council or other governing body of the city, town, township, borough, or village the facts that such an order has been made and that it has not been complied with, and it shall request such council or other gov- erning body to provide the money necessary to enable the board to abate such nuisance in the manner provided by law. Itshall thereupon become the duty of such governing body to act upon such certificate at its next meeting and to consider the appropriation of the money necessary to abate the nuisance so certified. If it be decided that the municipality has no money available for such purpose, such decision shall be trans- mitted to the board of health making the certificate, which said board shall thereupon communicate such decision forthwith to the director of the agricultural experiment station or his executive officer. 5.—If, in the judgment of the director aforesaid, public interests will be served thereby, he may set aside out of the moneys appropriated by this act such an amount as may be necessary to abate the nuisance found existing and to abolish the mosquito- breeding places found in the municipality which has declared itself without funds available as prescribed in the preceding section. Notice that such an amount has been set aside as above described shall be given to the board of health within whose jurisdiction such mosquito-breeding places are situated, and said board shall there- upon appoint some person designated by said director or his executive officer a special inspector of said board for the sole purpose of acting in its behalf in abating the nuisance found to be existing, and all acts and work done to abate such nuisances and to abolish such breeding places shall be done in the name of and on behalf of such board of health. 6.—If in the proceeding taken under section four of this act the common council or other governing body of any municipality appropriate to the extent of fifty per centum or more of the money required to abate the nuisance and to abolish the mosquito- breeding places within its jurisdiction it shall become the duty of said director of the agricultural experiment station to set aside out of the moneys herein appropriated such sum as may be necessary to complete the work, and in all cases preference shall be given, in the assignment of moneys herein appropriated, to those municipalities that contribute to the work and in order of the percentage which they contribute; those contributing the highest percentage to be in all cases preferred in order. 7.—In all cases where a municipality contributes fifty per centum or more of the estimated cost of abolishing the breeding places for salt-marsh’ mosquitoes within its 37713—Bull. 88—10——4 50 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES, jurisdiction, the work may be done by the municipality as other work is done under its direction, and the amount set aside as provided in section six may be paid to the treasurer or other disbursing officer of such municipality for use in completing the work; but no payment shall be made to such treasurer or other disbursing officer until the amount appropriated by the municipality has been actually expended, nor until a certificate has been filed by the director or his executive officér stating the work already done is satisfactory and sufficient to obtain the desired result, and that the arrangements made for its completion are proper and can be carried out for the sum awarded. 8.—In all investigations made under section two of this act the report to be made to the board of health requesting the survey shall state what mosquitoes were found in the territory complained of, whether they are local breeders or migrants from other ’ points, and, in the case of migrants, their probable source, whether the territory in question is dangerous or a nuisance because of mosquito breeding, the character of the work necessary to abate such nuisance and abolish the breeding places, and the probable cost of the work. Said board of health must then proceed to abolish the breeding places found under the general powers of such boards, but if it shall appear that the necessary cost of the work shall equal or exceed the value of the land without increasing its taxable value, such board may apply to the director aforesaid, who may, if he deems the matter of sufficient public interest, contribute to the cost of the neces- sary work, provided that not more than fifty per centum of the amount shall be con- tributed in any case, and not more than five hundred dollars in any one municipality. 9.—All moneys contributed or set aside out of the amount appropriated in this act by the director of the agricultural experiment station in accordance with its provisions shall be paid out by the comptroller of the State upon the certificate of said director that all the conditions and requirements of this act have been complied with, and in the case provided for in section five payments shall be made to the contractor upon a statement by the person in charge of the work, as therein prescribed, attested by said director, showing the amount due and that the work has been completed in accord- ance with the specifications of his contract. - 10.—For the purpose of carrying into effect the provisions of this act, the said director of the state agricultural experiment station shall have power to expend such amount of money, annually, as may be appropriated by the legislature; provided, that the aggregate sum appropriated for the purpose of this act shall not exceed three hundred and fifty thousand dollars. The comptroller of the State shall draw his warrant in payment of all bills approved by the director of the state experiment station, and the treasurer of the State shall pay all warrants so drawn to the extent of the amount appropriated by the legislature. 11.—This act shall take effect November first, one thousand nine hundred and six. Approved April 20, 1906. This law was drafted only after the most careful observations by Doctor Smith and his assistants, and after they had made themselves perfectly familiar with the conditions existing in the salt-marsh area in New Jersey and with the exact life histories of the different species of mosquitoes involved, and also after preliminary drainage work had been undertaken and carried to successful conclusion over part of the area without the assistance of state funds. Doctor Smith had found that three species, of approximately similar habits, develop in the salt marshes of New Jersey and migrate inland for long distances—up to 40 miles in some instances—thus making local work on the part of inland communities by no means > DRAINAGE MEASURES. 51 perfectly efficient. Citizens’ organizations had, for example, done excellent work in the way of destroying household and other fresh- water breeding mosquitoes, in South Orange, Summit, and other inland towns; but occasional inland migrations of swarms of salt- water species necessitated the retention of house screens and dis- couraged the community workers. The salt-marsh species Doctor Smith found to be Aédes cantator, A. sollicitans, and A. teniorhynchus. The former is the more northern and earliest, forming the bulk of the specimens on the marshes north of the Raritan River. South of that point cantator makes an early brood only and sollicitans is the abundant species during the rest of the season until late fall, when cantator sometimes reappears. He finds that teniorhynchus is never so common as the others and is a midsummer species. It was a most important discovery when Doctor Smith and his assistants found that all of these species laid their eggs in the marsh mud, and that these eggs may retain their vitality for three years, even if | repeatedly covered with water. He found that every time a marsh becomes water-covered some eggs hatch, and if the water remains long enough the larve reach maturity. On account of the possible long duration of the egg stage the problem seemed to be to permit or even favor the hatching of all of the eggs, and then to provide for the removal of the water so rapidly that none of the larve could come to maturity. ) To accomplish this end a system has been developed by which the force working under the state entomologist makes deep, narrow ditches in the salt-marshes by means of special machinery. These ditches are 30 inches deep and 10 inches wide, the sides being per- pendicular. The upper 12 or 18 inches of the ordinary salt marsh is peat or turf, and the water drains readily from it. Below this peat is sand, mud, or clay; and at 30 inches a depth has been reached which is below high-water mark and below the point at which vege- tation is likely to start. The ditches are placed from 50 to 200 feet apart, depending upon the character of the marsh, but more often 200 feet apart than less. Anticipating the ultimate passage of a state bill, work of this char- acter was begun on the Shrewsbury River in 1902, and at the present time both shores are now drained to the full length of the river. In 1903-1904 the marsh areas belonging to the cities of Elizabeth and Newark were drained at the expense of the cities, and in 1906 systematic drainage work was begun at the Hackensack marshes and continued along the shores of Middlesex and Monmouth counties, along both shores of the Raritan River, and along the numerous small rivers and creeks running into the Newark and Raritan bays and into the Arthur Kill. 4 52 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. 3 During the year 1906, and in the preceding experimental tile | 4,900 acres of marsh joni were drained and 710,000 feet of ditehis were put in. During the season of 1907, 10,951 acres of territory were cleaned up and 1,505,524 feet of ditching were put in. During the season of 1908, 6,669 acres of marsh land were dealt with and 888,650 feet of ditching was made. Out of the 1909 appropriation 2,672 acres of marsh were drained with 329,800. feet of ditching. This gives a grand total of 25,192 acres of marsh land and 3,633,974 feet of ditches. The area extends from the Hackensack at Secaucus to the mouth of Toms River on Barnegat Bay, a distance of nearly 70 miles of © shore line. In addition there are about 10 miles on Long Beach in which experimental work was done among the sand hills, in the pockets where the marsh mosquitoes bred whenever there was a storm or a storm tide to fill them. Here no ditches could be made because the layer of turf was very thin and below it was sand. Nor could outlets be obtained to tidewater without the expenditure of disproportionately large sums. ~The smaller depressions were filled with brush held in place by a layer of sand, and this served to gather and hold the blowing sand in high winds, causing a complete filling after a year or two. The larger depressions -were drained to a center where a pond varying from 6 to 15 feet square was dug 3 or 4 feet deep and a large barrel sunk into the center. This brought the line down below the level of the bay and kept water permanently present; in fact, there was an appreciable rise and fall of water with the tides, and it gave outlet to all the water that drained naturally to these low points. Ditches were dug along the natural drainage lines to these ponds, and the latter were then stocked with killies (/wundulus sp.). Some of these pools are now three years old, and the fish have multiplied. Altogether this plan has worked well and required little looking after. As to the amount expended, the state appropriations make a total of $58,500. About $10,000 has been spent by various municipalities, and probably $75,000 would cover what has been spent in marsh- mosquito work in New Jersey, counting in the local improvements made. ‘This includes also the cost of administration since 1905. The total estimated cost of the marsh work in the State is $350,000, and up to date the cost of the work actually done is within the amount estimated for that work. " " The work has been entirely original in its chupada from the - beginning of the observations upon the most unexpected habits of the insects, through the development of special machinery, and the ascer- taining of the important fact that this simple and very rapid and economic form of drainage meets the important requirement of stopping the breeding of these extremely annoying migratory forms. ‘THE VALUE OF RECLAIMED LANDS. 53 The writer has visited the marshes, has seen the excellent results of the work accomplished, and has watched the active operation of digging the ditches. It is possible to walk with dry feet over the drained marshes, and the crop of hay the first year after ditching doubles in quantity. A bit of work excellent in its results and very economical in its cost, in the way of the drainage of an upland marsh, is described by Doctor Smith in his report for 1908. A new normal school was about to be constructed on Montclair Heights, and there were swampy areas near by which acommittee of the state board of education con- sidered to be dangerous as mosquito-breeding places. Doctor Smith caused an inspection to be made early in April, and found that there was a danger point in which not only the ordinary pool mos- quitoes but malarial mosquitoes could develop. At a cost of $250, 3,000 feet of ditching was placed or improved, and all the surface water was drained to a culvert through a railroad embankment. The heavy rains of May gave excellent opportunity for testing the effectiveness of the work, and no mosquito breeding was found there throughout the season. THE VALUE OF RECLAIMED LANDS. GENERAL RECLAMATION WORK. The general value of lands reclaimed from swamps is obvious. Practically all of Holland has been reclaimed from the sea. Large areas of the most valuable farming land in the world have been re- claimed from nonproductive swamps. To the nonproductiveness of swamp land must be added the great danger that exists in its contin- uance through the invariable presence of disease-bearing mosquitoes. The drainage of swamps not only destroys unlimited breeding places of mosquitoes, but vastly increases the value of the land for farming purposes and for other utilitarian uses. Hither reason amply pays for the operation. The late Prof. N.S. Shaler, in his report to the North Shore Improvement Association, showed that fields gained by marsh drainage possess the greatest fertility and their endurance to cropping without manuring exceeds that of any other agricultural land except possibly arid regions which are irrigated. The range of crops is great and includes all ordinary farm and garden crops except in some places Indian corn. Reclaimed swamp lands are especially adapted for truck farming, because it is easy to maintain the level of under- ground water where the roots of the plants can reach it. Professor Shaler shows that the larger part of the best irrigable land in Holland, and much of that in Belgium, northern Germany, and eastern England has been gained from what was originally tidal fields. He estimates not less than 10,000 square miles in those countries to have been redeemed in this way. 54 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES, The only large example of diked and improved marshes in the north- eastern United States is at Green Harbor, Mass., where 1,200 acres have been won to tillage, about one-half being used for hay fields and the other for different crops. The result obtained in the farm- ing of this land is excellent. Asparagus has produced large crops continuously for more than twenty years without the use of any fertilizer. Prof. Milton Whitney, Chief of the Bureau of Soils, of the United States Department of Agriculture, some years ago drew up the follow- ing statement at the request of the writer, concerning the value of reclaimed swamp land: Swamp lands, by virtue of their position, become the repository of highly fertile material washed from the uplands by the rains. As a general rule, the immediate surface of any soil is the most fertile portion of that soil, resulting from the fact that this surface material is in physical condition, and most exposed to the action of the weather, the sun, rains, and air. This surface is the first portion removed during rains, and is the portion carried down into the swamps and deposited. When erosion goes on at such a rapid rate that both the surface and the underlying raw soil are washed away, the resulting bottom land deposit is frequently sterile. Witness the mud flats and swamps along the Sacramento River, in California, which have been covered with mud from the hydraulic mines of the Sierra Nevadas. Here large areas have been ruined by the mud, and will not become fertile until the weather has acted upon the material long enough to make the soil an acceptable medium for plant growth. Fortunately, most of our lowlands and swamps receive only the more gentle washing or the most fertile materials from the uplands. Swamp lands contain an unusual amount of organic matter, and for that reason are easy to maintain in proper tilth, light to work, and warm. From their low position, water is generally abundant, or easy to obtain for irrigation by pumping or diversion from nearby streams. Swamp lands and tide marshes are considered the most valuable of lands in the world’s older countries. Their inherent fertility is recognized, and the ease with which they are cultivated and irrigated is greatly appreciated. In England for two hundred years the tide lands have been under reclamation, and to-day over 1,000,000 acres are in a “‘matchless state of fertility.”’ In Holland extensive areas have been reclaimed from the sea. The greater part of the country lies at or below the level of the sea, and is reclaimed from a jungle of swamps and savannas. Holland to-day represents one of the most successful attempts at swamp reclamation. Lakes have been drained by diking and pumping, and ee are now on foot to drain the Zuyder Zee, an arm of the ocean. In our own country swamp reclamation has been carried out on a large scale in ae Middle Western States. Ohio, Indiana, Illinois, Michigan, and Wisconsin have great areas of productive land once swamp but now the most fertile and reliable land in those States. The tide marshes around Puget Sound, in Washington, have been lying untouched until within the last few years, but the recent great influx of Scandi- navians has resulted in a movement toward the reclamation of these lands, and excel- lent farms are being established. In California one of the greatest areas of swamp peat land in the world lies in the | Sacramento-San Joaquin Delta. Over 1,500,000 acres of peat from 6 to 40 feet thick are ready for reduction in productive capaeiling and to-day large areas are being reclaimed. Yields of 500 bushels of potatoes, 6,000 pounds of asparagus, 60 bushels of barley and oats have been common, and with proper farming such yields should continue to be common. a | | | THE VALUE OF RECLAIMED LANDS. 55 Wherever properly reclaimed swamp lands are found their fertility is recognized; almost without exception they are more fertile than surrounding uplands. They are frequently used in special crop production, such as in growing celery, asparagus, cranberries, or onions, but in dairying or general farming they are unexcelled as per- manent pasture or hay land. The consensus of opinion in districts where swamps have been reclaimed and farmed for many years is that there is no more valuable por- tion of the farm than the swamp, properly reclaimed. There is much swamp land in the United States within easy reach of the best markets. New Orleans is surrounded by swamps, but here the problem of reclamation is rendered exceedingly difficult owing to the vast area involved and the periodic invasion by the Mississippi River in front, and Lakes Borgne and Pontchartrain in the rear. The city of New York is in the immediate neighborhood of vast areas of swamps and marshes, and even the partial drainage of this land is being productive of admirable results. The great value of stable land in the vicinity of New York for manufacturing purposes is uncontested, and even the partial drainage of the breeding places of salt-marsh mosquitoes in portions of New Jersey adjacent to New York has resulted, aside from limiting the mosquito supply, in the increase in value of the lands to the owners. After the first ditching the crop of salt hay nearly doubles. The operations carried on conjointly between the city of Brooklyn and the town of Sheepshead Bay, a few years ago, showed the remunerative results to be obtained by simple and beneficial operations. The contents of the ash barrels of the city of Brooklyn were conveyed out into the salt marshes upon specially constructed trolley tracks and in large metal tanks. The tanks were so made that upon reaching the ter- minus they were taken up by machinery, carried out by an overhead trolley line, and by machinery dumped at a given spot. In this way some hundreds of acres of salt marsh were covered with a 12-foot layer of the contents of the ash barrels of Brooklyn. The layer was packed down by water and contained so much organic matter that almost immediately grass and sunflowers began to grow. At the end of the second year enough soil had formed so that Italians had begun to plant cabbages and other vegetables. . The. Government is taking up the subject of reclamation of swamp lands through its Reclamation Service, and extensive surveys are being made by the United States Geological Survey. Under the United States Department of Agriculture appropriations have been made for some years to enable the Secretary of Agriculture to inves- tigate and report upon the drainage of swamps and other wet lands _and to prepare plans for the removal of surplus waters by drainage. A number of interesting and important publications have already been issued by the United States Department of Agriculture, two of which are of general interest, namely, Circular No. 74, Office of Experiment Stations, Excavating Machinery Used for Digging 56 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES, Ditches and Building Levees, by J. O. Wright (pp. 40, figs. 16); and Circular No. 76, Office of Experiment Stations, The Swamp and Over- flowed Lands of the United States, by J. O. Wright (pp. 23, pl. 1). The first of these publications described the use and construction of different classes of dredges, including dipper, clam-shell, rotary, roller, scraper, elevator, and hydraulic dredges, and drag boats; first cost and cost of operation of dredges; machines for building levees; machine for tile ditching. The second gives an estimate of the area of swamp lands in the different States, its ownership, present value, cost of reclamation, and probable value when reclaimed, and dis- cusses the state laws relating to drainage, It is shown in the lat- ter circular that there are in the United States 119,972 square miles of swamp lands, an area which, collected together, would be as large as England, Ireland, Scotland, and Wales together, or larger than the six New England States, New York,-and the northern half of New Jersey. It would make a strip 133 miles wide reaching from New York to Chicago. Not all of this swamp land, however, is suited for agriculture, but from the data collected by the Office of Experi- ment Stations of the United States Department of Agriculture, it — seems certain that in the eastern portion of the United States there © are 77,000,000 acres that can be reclaimed and made fit for cultiva- tion by the building of simple engineering structures. It is a notice- able and significant fact that 95 per cent of this entire area is held in private ownership. The followmg paragraphs taken from this Circular No. 76 express the desirability of such drainage from the monetary point of view in very forcible terms: There is no question as to the fertility of swamp or overflowed land, and when it is protected by embankments to keep out the overflow and is relieved of the excess of water by proper drainage its productiveness is unexcelled. In nearly every one of the States large areas of similar lands have been reclaimed by draining and embanking and have proven to be the most productive farm lands in the districts in which they are located. Illinois, Indiana, lowa, and southern Louisiana have taken the lead in work of this kind, and in no other part of the country do we find more profitable or higher-priced farms than in those States. Along the Atlantic coast sufficient work has been done to indicate that the vast extent of salt marsh reaching from Maine to Florida can by proper methods be won to agriculture, and when reclaimed the soils. are especially adapted to market gardening. To ascertain why these lands have been allowed to remain so long in their present state we must look to some cause other than their lack of fertility, as this has been fully established by chemical analyses of the soil and by hundreds of productive farms that have been made from such lands. In the early settlement of our country the farms were located on what were con- sidered the most desirable tracts, determined by accessibility, natural water supply, and the fertility of the soil. As civilization extended westward the home seeker selected the rolling prairie that needed little or no drainage, so that the swamps and overflowed lands were passed by, and only recently has an imperative demand arisen for their reclamation. ‘The desirable farming land is practically all occupied or held for speculation, and to meet the needs of our steadily increasing population it is neces- a a ee ee THE VALUE OF RECLAIMED LANDS. 57. sary for this swamp land to be drained and put to propef use. Its nearness to market and its great fertility make it very desirable for small farms. } Can these lands be drained, what will it cost, and how can the work best be done are questions of vital interest to the American people. After considering what has been done to reclaim the marshes of Holland, two-fifths of which lie below the level of the sea, and the difficulties that have been overcome in draining the fens of England, it would be a reflection on the skill and intelligence of the American engineer to pro- claim the drainage of our swamp lands impossible. On the contrary, the engineering problems are simple, as most of these lands are several feet above sea level and have natural creeks or bayous that need only to be improved by straightening, widening, and deepening to afford outlets for complete drainage. In case of some of the river bottoms and the salt marsh along the coast it is necessary to build levees to prevent over- flow and to construct internal systems of drainage with sluice gates or pumps to dis- charge the water from within, and by the use of modern machinery this work is neither difficult nor expensive. Levees can be built and ditches excavated with suitable dredges at a cost ranging from 7 to 16 cents per cubic yard. Large works in swamps where the land is overflowed are readily and cheaply constructed in this manner. As to the cost of draining these lands, and whether or not it will pay, we have but to refer to the numerous works of this kind that have been completed. In those States where large areas of swamp land have been thoroughly drained by open ditches and tile drains the cost ranges from $6 to $20 per acre, while in places where tile drainage was not required the average cost has not exceeded $4 per acre. Judging from the prices which prevail in a large number of these districts where work of this kind is being carried on, it is safe to estimate that the 77,000,000 acres of swamp can be thoroughly drained and made fit for cultivation at an average cost of $15 per acre. The market value of these lands in their present shape ranges from $2 to $20 per acre, depending upon the location and prospect of immediate drainage, with an average of probably $8 per acre. Similar lands in different sections of the country that have been drained sell readily at $60 to $100 per acre at the completion of the work, and in many instances, when situated near large cities, they have sold as high as $400 per acre. To determine whether or not it will pay to drain these lands we have but to consider the following figures: Cash value of 77,000,000 acres after thorough drainage, at $60 per acre. $4, 620, 000, 000 Present value of this land, at $8 per acre............. $616, 000, 000 Cost obaraimare, at flo per acre... .222:-.....-.2--4.- 1, 155, 000, 000 Walue otiand andicostiol draming..- 2-22... .222 22 Sel... 1, 771, 000, 000 REBAR AEM RV NIG Sect altos eM Weds es ag tk be 2, 849, 000, 000 These figures, though large, are not fanciful, but are based on results obtained in actual practice in different sections of the country where work of this kind has been done. An extended investigation shows that in every case where a complete system of drainage has been planned and carried out the land has increased in value many fold. In some instances, however, much time and money have been wasted because the work was undertaken without any well-defined plan or it was not sufficient to afford adequate and complete drainage. The reclamation of swamp and overflowed lands is no longer an experiment; it has become a highly profitable business when based on correct principles. The methods of drainage practiced in different parts of this country and in some of the foreign . countries are being carefully considered, and many experiments are being made to determine the best and most economical methods of draining land, and the information thus collected is being classified and the results compared and general rules deduced which, if followed, will in all cases bring highly beneficial results. The comparative cost of the different methods of doing the work and the most satisfactory way of pro- viding funds are also being duly considered. ry, ee OT a * y Wt fo. ey 58 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. = Were this 77,000,000 acres of swamp and overflowed land drained and made healthful and fit for agriculture and divided into farms of 40 acres each, it would provide homes for 1,925,000 families. Swamp lands, when drained, are extremely fertile, requiring but little commercial fertilizer, and yield abundant crops. They are adapted to a wide range of products and in most instances are convenient to good markets. While an income of $15 to $20 per acre in the grain-producing States of the Middle West is considered profitable, much of the swamp land in the East and South would, if cultivated in cabbage, onions, celery, tomatoes, and oo vegetal yield a net income of more than $100 per acre. In addition to the immediate benefits that accrue from the increased productiveness of these lands, a greater and more lasting benefit, would follow their reclamation. The taxable value of the Commonwealth would be permanently increased, and health- fulness of the community would be improved, mosquitoes and malaria would be banished, and the construction of good roads made possible. Factories, churches, and schools would open up, and instead of active young farmers from the Mississippi Valley emigrating to Canada to seek cheap lands they could find better homes within our own borders. Holland, two-fifths of which lies below the level of the sea, has been reclaimed by diking and draining, and now supports a population of 450 per square mile. Her soil is no better than the marshes of this country, and her climate not so good as that of the Southern States, yet we have within our border an undeveloped empire ten times her area. There is no good reason why this condition should longer continue, and it is to be hoped that the American people will soon take steps to abate this nuisance and make these lands contribute to the support and upbuilding of the nation. ; In an important article by Mr. H. C. Weeks, in the Scientific American Supplement for January 5, 1901, on the subject of drainage work, the following interesting statements are made: Cases exist, however, of persons being unwilling to be convinced, and continuing their opposition even after a successful reclamation, as are seen in the official records of Massachusetts, while examinations by the State have shown a great improvement . in the sanitary and agricultural conditions. In the instance of Green Harbor, in that State, it is shown that the death rate of the reclaimed district averages lower than the general death rate of the State; that there is a steady increase in summer visitors, and that many houses are being built. The testimony of persons of wide knowledge and ample experience in the science and art of agriculture is adduced, showing the good results in that field, and yet it fails to silence opposers. Besides mentioning the remarkably heavy crops of hay, much preferred by his horses to the best from the uplands, also the excellent crops of strawberries and vegetables raised in these lands, one such qualified observer gives his experience as to asparagus in such convincing words that they are quoted in full: ‘‘While visiting the Marshfield Meadows on April 19, 1897, I found asparagus already up, very nearly high enough to cut. I was sur- prised at this, for my own asparagus had but just appeared above the surface of the ground, although growing on land so warm that I am usually first to ship native aspara- gus to Boston market. I was also surprised at the size of the stalks, they being much larger than the first set of stalks that appear on my land. When I consider the fact that the land on which this asparagus was growing has produced large crops every year for twenty years without fertilizers of any kind, and still produces better crops than my land, which has had $600 worth of fertilizers to the acre applied to it during the last twenty years, it convinces me that this land, for garden purposes, surpasses any which I have everexamined * * *,”’ We realize, in a measure, the great value of the material which nature has for ages been storing up for man’s future use, if he be wise enough to avail himself of it. THE VALUE OF RECLAIMED LANDS. 59 The drainage work done by other countries has given many prac- tical examples of beneficial results from the mosquito standpoint, and from other points of view as well. The details have very recently become available, through the kindness of the United States consul at Milan, Italy, of very extensive drainage operations carried on near Milan, which involved the reclamation of nearly 80,000 acres of land. These details may be found in the Scientific American Supplement. No. 1637, May 18, 1907, pages 26233 to 26235. The work cost $3,200,000, and the annual cost of operation is estimated at $16,000. The beneficial results are summarized as follows: 1. In both Mantua and Reggio this tract, comprising 77,867 acres, cultivable only for a sparse crop of poor hay and, on account of the vapors arising from its stagnant swamps, dangerous for pasturage during practically all the year, has been made cultivable, in one year, for wheat, grapes, fruits, and hay, and rendered good for cutting into farms on which people can erect homes in safety. 2. The market values, not only on the 78,000-acre tract but on all contiguous terri- _ tory, even to the outer bounds of the affected provinces, have leaped to figures equal to two or three times those prevailing before the opening of the Bonifica, i. e., from $120 to $250 or $300 per acre. 3. Farm labor, which formerly expressly avoided these provinces, and made diffi- cult the harvesting of the extensive crops, has been attracted there by the changed conditions; while on account of the demand created by the active development of the drained tract, wages have not been knocked down by the plentitude of supply. 4. Live-stock maladies are under better control. 5. The public health has been afforded a sure and scientific protection. SALT-MARSH LANDS IN NEW JERSEY. So much work has already been done in New Jersey that, as repeatedly pointed out in this work, the value of the operations already carried on in that State is very great, if only as an indication of what can be and should be done elsewhere. The whole question of the New Jersey salt marsh and its improvement has been consid- ered by Dr. John B. Smith in Bulletin No. 207 of the New Jersey Agri- cultural Experiment Station. In this work he gives a consideration of the location of the salt-marsh area, the kinds of salt marsh, the vegetation on the marshes, the present value of the marshes, their actual value, effect of drainage on crops, the needs of salt grass and black grass, and a general consideration as to how the marshes may be reclaimed and who is to pay the expense. It appears that the present value of the marshes is very small. As a matter of fact, they are either not taxed at all or at such a low rate as to add little to the income of the taxing body. Some of the owners have never paid any taxes, and in some of the townships - there is no record of ownerships in the assessor’s hands and _ there- fore no notices can be served. It is pointed out, as an evidence of the recognized worthlessness of such land, that none who work on them consider in the least the results of interference with natural 60 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. drainage; railroads build embankments across them, and pay no attention to the water courses except large creeks. The result is that the marsh often becomes water-logged, and a good salt-hay meadow is turned into a quagmire, and not even the owner protests. Rail- roads cut sods from the meadows without inquiry as to the ownership of the land, and holes of all sizes are scattered over the meadow, most of them unconnected with tidewater, leaving stagnant pools in which mosquitoes breed. ! ! He points out that all salt marsh, of what he names the third type, - which is that area above mean high tide and more or less completely covered with vegetation, may be made to produce an income of from $10 to $40 per acre annually, and that there are many hundreds of acres that do produce such incomes. In considering the effect of drainage upon crops he gives a aie of interesting instances, three of which are quoted: The Newark meadow has an area of about 3,500 acres, and hay has been cut on parts of it for many years. Before the 90’s it was generally cut by men who wished to use jt as food for stock or as bedding, and some ditches were cut by those who noticed that well-drained land produced much better crops than such as were either too dry or water-logged. After the 90’sa number of banana houses opened in Newark and created a demand for salt hay to use in layering the ripening fruit. This demand led to the cutting of more territory around the edges of the marsh, and $5 a ton was paid for the crop. With the introduction and increase of the glass industry the demand for hay, to be used as packing, increased steadily, and yet greater areas were cut; and in order to get at these areas the cutting was done in the winter, after the meadow was frozen solid, for at no other time could the product be carted off. And this was the condition of affairs in 1904, when the mosquito drainage was done by the city, but under the supervision of the writer. It might be said here that this drainage work was not looked upon with any favor by owners and haymakers, the latter especially protesting vigorously. One man threatened to smash the ditching machine, and yet another promised to shoot the first man that set a spade into his property. The work went on, nevertheless, and altogether nearly 400,000 feet of ditches went into this 3,500 acres. The results are as follows: On the Hamburg section, where in 1903, on an area nearly one mile square, about 100 tons of hay were taken off during the winter, 250 tons were carted off in 1904, only one year later. The meadow has hardened up right along, and in 1907 nearly the entire area was cut by machine, and a crop of 800 tons, valued at $7.50 per ton, is harvested. Yet a worse place was the area, about one by three-fourths of a mile, known as the Ebeling tract, little more than a sunken meadow before 1904, from which no more than 30 tons of usable grass were obtained. After the ditching the meadow began to rise and improve, and at present writing is at least seven inches above its 1903 level, and correspondingly improved in texture. Thecrop has increased from 30 tons to 600 tons, not quite so good as the other, but worth an average of $7 per ton. Other areas which had theretofore produced nothing are now being cut. The total cut in 1903 was between 1,000 and 1,200 tons, the 1907 crop will come close to 3,000... And that is not the limit of productiveness. Forty years ago the Elizabeth marshes, containing about 2,200 acres, were quite generally cut over and good crops of hay were obtained. There was considerable ditching done, but it was not kept up, and as the marsh was crossed and cut up by the railroads without regard to the drainage system, matters became gradually worse; the meadow rotted, the black and salt grass was replaced by sedges and other useless stuff, and less and less was cut each year until, for a decade past, little or nothing has been THE VALUE OF RECLAIMED LANDS. 61 cut from the area west of the Central Railroad. Where as much as 5,000 tons had once been harvested, less than a thousand tons were harvested in 1903. In 1906 ditches were cut in the southeastern section of the meadow in the course of the mosquito work, and an area on which hip boots were needed in that year can now be safely traveled dry shod. Where we found sedge and useless grasses over two-thirds of the area in 1905, on that same proportion we now have good salt and black grass. In another year, if the ditches are not interfered with, the sedge will be practically out. The balance of the area was ditched early in 1907, all the work being.completed early in July. Shallow depressions that have been water covered and mosquito breeders for twenty years are now dry and covered with the salt-marsh flea-bane. The grass which was ten to twelve inches high last year is now twenty to twenty-eight inches high and much more dense. For the first time in nearly twenty years hay is being again cut in areas west of the railroad and in the area between Great Island, Elhzabeth- port and the Central Railroad. In draining the Shrewsbury River marshes in 1904, the same sort of opposition from hay producers was encountered that we met on the Newark marshes, and it was objected that the ditches cut up the land and made work harder. Nevertheless, the work was done and the result is a crop just double—mostly from longer, thicker grass. Before 1904, two tons per acre was considered a good crop; now, good and bad together, it _averages four tons, and local conditions furnish a market that pays $10 per ton. In his annual report for the year 1908, Doctor Smith states that his . investigations showed that a very small part of the salt-marsh area produces as great a crop as it should, and that what is produced does not bring as good a price as it should. The market for salt hay is slight, due in part to the character of the crop and partly to the uses to which it is put. Since the crop is not certain it can not be relied upon, and the price varies with the size of the harvest. Salt hay is used largely for packing, and the amount demanded depends upon business conditions. In 1907 there was a very large crop of hay, but there was a business depression at the same time which brought about so low a price as to scarcely repay harvesting. He shows that salt hay is altogether too valuable to be used for packing material alone, and that if an annual crop could be expected it could be used to sup- plement upland hay in feeding horses and cattle. The drainage work done by Doctor Smith under the state mosquito law will put the meadows into such shape that the amount of hay produced will be increased without increase of cost except in harvesting, and will enable the production of dependable crops. He states that on July 21, 1908, he had the opportunity of seeing, at Stratford, Conn., an area of about 1,500 acres of salt marsh drained and partly diked and reclaimed. The largest part of the acreage was devoted to raising salt hay of the best quality, for which good prices were received. On the diked marsh 100 acres had been kept free from salt water since 1904. On this territory strawberries, asparagus, onions, and celery were being raised, and, while the asparagus was not of the best quality and the strawberry plants were in no way unusual, the onions and celery were of the best—in fact the celery was so good that most of 62 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. the market gardeners in that vicinity preferred to get their supplies from this source. Doctor Smith points out that there are many hundreds of acres along the shores of Barnegat Bay, and especially along its upper por- tion, where a very small amount of diking will serve to keep out salt _ water and fit the land for certain truck crops. He also shows that along a large portion of the Barnegat Bay line cranberry plants grow annually to the very edge of the salt-marsh line, but that these could not be improved because there was no way out across the marsh for surface water. With the ditching going on, this land will become available in large part at least and will allow the owners to derive a revenue from land which is at present practically nonproductive. Of course taxes will then be raised and the income of eG townships in which this land lies will be increased. THE PRACTICAL USE OF NATURAL ENEMIES OF MOSQUITOES. SALAMANDERS, DRAGONFLIES, PREDACEOUS MOSQUITOES, AND FISH. Almost no practical use has been made artificially of the natural enemies of mosquitoes except with fish. It is true that about 1898 Mr. Albert Koebele imported from California into Hawaii a large num- ber of western salamanders (Diemyctylus tortosus Esch.), which were liberated in the upper part of the Makiki stream in the hope of redu- cing the large number of mosquitoes breeding in small pools and in the taro fields. He kept two of these salamanders for several weeks in an open tank and they devoured all mosquito larve that occurred there; and while hundreds of the newly hatched mosquito larve could always be observed, none of them ever reached full growth. Whether these salamanders have increased in Hawaii and at present form an important element in the mosquito environment is not recorded. Among the predatory insects it has been frequently suggestea that dragonflies are such important mosquito enemies that efforts should be made to devise some artificial means of encouraging their increase, and in fact the late Dr. R. H. Lamborn, of New York and Philadelphia, offered a series of prizes for the three best essays regarding the methods of destroying mosquitoes and house flies, especially designating the dragonfly for careful investigation. The prizes were awarded to Mrs. Carrie B. Aaron, of Philadelphia, and Mr. A. C. Weeks and Mr. Wm. Beutenmueller, both of New York, but none of the essayists was able to solve the problem of the practical breeding on a large scale of dragonflies for mosquito extermination. It has been proposed to breed mosquitoes of the genera Psorophora and Megarhinus, the larve of which are extremely active and feed so voraciously upon the larve of other mosquitoes, but Psorophora PRACTICAL USE OF NATURAL ENEMIES OF MOSQUITOES. 63 ¢ itself in the adult condition is a voracious biter and is a potential carrier of disease, so that to breed it for predaceous purposes is hardly to be considered; in other words, the remedy might prove worse than the disease. However, Dr. Oswaldo Goncalves Cruz, director-general of the board of health in Rio de Janeiro, told the writer in November, 1907, while on a visit to Washington, that Lutzva bigot is used in Rio practically to destroy the larve of the yellow-fever mosquito. The Lutzia larve are exclusively carnivo- rous, and this species is introduced in regions where the mosquito Ei fends, and its larve destroy the other larvee as efficaciously as do fish. For a long time fish have been used practically on a small scale. For example, it was stated a number of years ago in Insect Life that mosquitoes were at one time very abundant on the Riviera in south Europe, and that one of the English residents found that they bred abundantly in water tanks, and introduced carp into the tanks for the purpose of destroying the larve. It is said that this was done with success, but it is rather certain that the fish must have been _ some other form than carp. It is probable that the fish in question was the common goldfish (Carassius auratus). In the southern United States for many years intelligent persons here and there have introduced fish into water tanks for this purpose. Mr. E. A. Schwarz found in 1895 that at Beeville, Tex., a little fish was used. ‘The fish was called a perch, but its exact specific character isnot known. Prior to 1900, Mr. F. W. Urich, of Trinidad, wrote the Bureau of Entomology that there is a little cyprinoid, common in that island, which answers admirably for the purpose. In a letter to the Bureau of Entomology Mr. J. B. Fort, of Athens, Ga., writes that about 1854 his father, Dr. Tomlinson Fort, living at Milledgeville, Ga., found that mosquitoes were breeding extensively in a cistern owned by certain livery-stable keepers. They refused to use oil upon their cistern, and Mr. Fort was instructed by his father to catch some small fish from a creek near by and place them in the cistern. About a dozen or more small fish were so placed, and in a day or so all of the larvee were destroyed. This instance is mentioned as indica- ting the early use of fish on a small scale in cisterns. In ‘‘Mosquitoes”’ (1901) the writer recommended the practical use of sticklebacks, top-minnows (Gambusia affinis and Fundulus notatus), and the common sunfish or pumpkinseed, and these fish, especially the top-minnows and the sunfish, were used with success in a number _ of instances in small ponds. An instance has been described in a letter to the Bureau of Entomology by C. T. Anderson, of Anderson, Washington County, Fla., who wrote that he had a spring on his place that swarmed with mosquito larve in the summertime. He got about a dozen top-minnows and put them into the spring without 64 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. telling the rest of the family. In a day or two a member of the family remarked that there were no wrigglers in the water. Mr. Anderson verified the observation, and after many months was able to state that no mosquito larvee had been seen since. The common goldfish proves to be an excellent mosquito feeder and during the summer of 1901 Mr. Jacob Kotinsky, then of the Bureau of Entomology, conducted a series of laboratory experiments with goldfish in an aquarium. He found that they were voracious feeders on mosquito eggs, preferring them to larve. He further noticed that the fish, after taking several larve into the mouth, would eject some of them. Further, he found that in a large jar containing four goldfish and many hundreds of mosquito larve, a few of the larvee succeeded in transforming and emerging as adult mosquitoes. The food supply was evidently in excess of the capacity of the fish. At an earlier date than this Mr. H. W. Henshaw, of the Biological Survey of the United States Department of Agriculture, was staying at Fruitville, near Oakland, Cal. The house and neighboring houses were badly infested with mosquitoes. He found the source of supply to be a lily pond about 7 by 12 feet in size and fully 3 feet deep, which was fairly swarming with larve. He got a half dozen goldfish from San Francisco and put them into the pond. The following day they were so badly bloated that they could hardly swim, and in a few days there was not a single larva left. The fish bred in the pond and from the time of their introduction there was a very marked decrease in the number of mosquitoes in that general locality. Mr. William Lyman Underwood, of the Massachusetts Institute of Technology, in Science for December 27, 1901, described an interest- ing experience with goldfish: About six years ago, at my home in Belmont, near Boston, Mass., I constructed a — small artificial pond in which to grow water lilies and other aquatic plants and also to breed, if possible, some varieties of goldfish—though the latter object was a second- ary consideration. The advisability of making this pond had been somewhat ques- tioned on account of its close proximity to my house and the fact that such ponds are likely to become excellent places for the propagation of mosquitoes. Nevertheless, the plan was carried out and the pond was stocked with goldfish taken from natural ponds in the vicinity where they had been living and breeding, to my personal knowl- edge, for a number of years. The aquatic garden has proved a success and the goldfish have meantime thriven and multiplied. Moreover, no mosquitoes attributable to the pond have appeared and I have been unable to find any larve in it, although I have searched repeatedly and diligently for them. I have always believed that the absence of mosquito larvee from this pond was due to the presence of the goldfish, and I have so stated in a paper, ‘‘On the Drainage, Reclamation, and Sanitary Improvement of Certain Marsh Lands in the Vicinity of Boston” in the Technology Quarterly, XIV, 69 (March, 1901), as follows: ‘‘In the water (of this pond) are hundreds of goldfish that feed upon the larvee of mosquitoes and serve to keep this insect pest in check.’”? * * * JT took from the pond a small goldfish about three inches long and placed it in an aquarium where it could, if it would, feed upon mosquito larve and still be under careful obser- vation. The result was as I had anticipated. On the first day, owing perhaps to the ‘ PRACTICAL USE OF NATURAL ENEMIES OF MOSQUITOES. 65 change of environment, and to being rather easily disturbed in its new quarters, this goldfish ate eleven larve only in three hours; but the next day twenty were devoured in one hour; and as the fish became more at home the ‘‘wrigglers” disappeared in short order whenever they were dropped into the water. On one occasion twenty were eaten in one minute, and forty-eight within five minutes. This experiment was frequently repeated, and to see if this partiality for insect food was a characteristic of those goldfish only which were indigenous to this locality I experimented with some said to have been reared in carp ponds near Baltimore, Maryland. The result was ' the same, though the appetite for mosquitoes was even more marked with the Balti- more fish than with the others. This was probably due to the fact that they had been in an aquarium for a long time before I secured them, and had been deprived of this natural food. JI also tried the experiment of feeding commercially prepared ‘‘goldfish food’’ and mosquito larve at the same time, and found thatin such a case the goldfish invariably preferred the larve. It is not as generally realized as it should be that goldfish will thrive in our natural northern waters. In my experience they can easily be bred in any sheltered pond where the water is warm and not fed by too many cold springs, and for many years they have been breeding naturally in many small ponds in the vicinity of Cambridge, Massachusetts. -When it is once understood that these fish are useful and ornamental, as well ‘as comparatively hardy, it is to be hoped that they will be introduced into many small bodies of water where mosquitoes are likely to breed, and thus be employed as a remedy for mosquitoes sometimes preferable to kerosene. The year 1908 in the island of Cyprus proved to be the most mala- rious year since 1885. Careful examination of conditions was made by Dr. George A. Williamson, whose report will be found in the Journal of Tropical Medicine and Hygiene, September 15, 1909, pages 271-272. A careful search was made in the marshes to the north and south of Larnaca, but no breeding places of Anopheles mosquitoes were found, and subsequent search showed that the malarial mosquitoes were breeding in the tanks and wells of private houses. Here kerosene could not be used, and the use of goldfish was advised. Wherever the advice was followed the results were perfect. One well, described by Williamson, was about 20 feet deep and had a wide mouth. This well contained Anopheles larve in enormous numbers, and of five persons living within its immediate neighborhood four became infected with malaria. This well, not being in use, was filled in, but a large tank which was near it was stocked with goldfish and all Anopheles larve were destroyed by them. _ An excellent discussion of the relative value of the different small fish for practical handling and for practical use against mosquito larve has been published by Mr. William P. Seal, a naturalist of many years’ experience in handling fishes, and the following para- ‘graphs taken from this article’ may be considered as authoritative: As a destroyer of Anopheles the writer has for several years advocated the use of ‘Gambusia affinis, a small viviparous species of fish to be found on the South Atlantic coast from Delaware to Florida. A still smaller species of another genus, Heterandria 4See Scientific American Supplement, vol. 65, No. 1691, pp. 351-352, May 30, 1908. 37713—Bull. 88—10——5 66 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. formosa, is generally to be found with Gambusia and is of the same general character. The females are about one inch long and the males three-quarters of an inch. Both of these species are known as top minnows, from their habit of being constantly at the surface and feeding there. The conformation of mouth, the lower jaw projecting, is evidence of their top-feeding habits. Both of these species are to be found in great numbers in the South in the shallow margins of lakes, ponds, and streams in the tide- water regions wherever there is marginal grass or aquatic and semiaquatic vegetation. They are also to be found in shallow ditches and surface drains where the water is not foul, even where it is but the fraction of an inch deep. In fact, if any fishes will find their way to the remotest possible breeding places of the mosquito, it will be these. And they are the only ones, so far as the writer’s observation goes, that can be consid- ered useful as destroyers of Anopheles larve. Gambusia is found in the Ohio Valley as far north as southern Illinois, where the winter climate must be at least as severe as that of the coast of New York and New Jersey. Dr. Hugh M. Smith, Deputy U.S. Fish Commissioner, informed the writer that he had examined the stomachs of several hundreds of Gambusia in the Chesapeake Bay and Albemarle Sound waters, and had found the contents to be principally mosquito larvae Scr * While, as has been stated, all fishes have some measure of usefulness, if only in the way of deterrent effect, there are only a few species likely to be found in waters in which mosquitoes breed. The most important of these are the gold fish (introduced), several species of Fundulus (the killifishes), and allied genera, three or four species of sunfish, and the roach or shiner, and perhaps one or two other small cyprinoids. In addition, there are a few sluggish and solitary species, like the mud minnow (Umbra) and the pirate perch (Aphredoderus). The sticklebacks have been mentioned in this connection, but the Atlantic coast species, and probably the entire family, are undoubtedly useless for the purpose, being bottom feeders, living in the shallow tide pools and gutters, hidden among plants or under logs and sticks at the bottom, where ' they find an abundance of other food. In the salt marshes there are myriads of killifishes running in and out and over them with each tide, while countless numbers of other and smaller genera, such as Cyprinodon and Lucania, remain here at all stages ofthe tide. Sonumerousand active are all of these, that there is no possibility of the development of a mosquito where they have access. Of the killifishes two species, Heteroditus and Diaphanous, ascend to the farthest reaches of tide flow, but it is a question as to whether they would prove desirable for the purpose of stocking land-locked waters, since they are a good deal like the English sparrow, aggressive toward the more peaceable and desirable kinds. Even Cyprinodon, which would at first thought be a valuable small species in this respect, is viciously aggressive toward goldfish and no doubt all other cyprinoids. It is so characteristic of all the cyprinodonts, that they can only be kept by themselves in aquaria. They are the wolves or jackals of the smaller species. The writer has come to the conclusion, after many experiments in both tanks and ponds, that a combination of the goldfish, roach, and top-minnow would probably prove to be more generally effective in preventing mosquito breeding than any other. The goldfish is somewhat lethargic in habit, and is also omnivorous, but there is no doubt that it will devour any mosquito larve that may come in its way or that may attract its attention. The one great objection is that they grow too large, and the larger will eat the smaller of them. That is one of the drawbacks to goldfish breeding. There is no danger of overpopulation, but there is of the reverse. Whether or not it is the same with the roach, they are never excessively numerous, although no doubt the most abundant and most widely distributed of the Cyprinide. They are largely the prey of predaceous fishes, and never approach to the numbers of the killifishes. Oe ISS NR Nd te? Nea eta ee ee Oe ee PRACTICAL USE OF NATURAL ENEMIES OF MOSQUITOES. . 67 But at all events they are not lethargic like the goldfish, being on the contrary one of the most active of the family, and equally at home in flowing or stagnant water. The roach is always in motion, back and forth, and around and about, on a never-ending patrol. _ The top-minnows would supply the deficiencies of the other two species, and in combination they should very thoroughly populate any waters not already stocked with predaceous kinds, and exercise an effective control. One of the great difficulties in the case is that there are dozens of kinds of insect larvee besides those of the mosquito, and other forms of life as well, which are natural and possibly preferred food of the fishes, thus requiring an enormous population, to devour them all. The larve of gnats, midges, ephemera, and other flies and insects which breed in the water, as well as the many small crustaceans, afford a menu of delicacies that would stagger a gourmand. The above combination of mosquito destroyers might be sup- _ plemented by twosmall species of sunfish, Enneacanthus obesus and E. gloriosus, which live among plants and would be a check on larve other than the mosquito. The black-banded sunfish, Mesogonistius chxtodon, would also be desirable for this purpose if they were not so difficult to obtain in large numbers. One or both species of Ennea- canthus can be found wherever there are aquatic plants. The above-mentioned five species in combination seem to be the most suitable for pond protection of all those which are known to thrive in still water and which in any degree possess the desired qualities. As has been stated, the killifishes would probably be found to be unde- sirable. In their natural habitat, the tidal streams and great expanses of small marsh, their efficiency is unquestioned. There are many places at the seashore where there are swales or hollows filled with grasses and bushes, which in periods of rainfall become breeding places for the mos- quito, especially of Anopheles. If these places are stocked with fish, the result is that when they dry up the fish perish, and the operation must be repeated after each filling. . The writer has suggested digging holes about four feet square down through the turf into the sand stratum in the deepest part. Two feet is usually sufficient to secure a constant water supply where the fish can exist until the hollow is again rain-filled. Cyprinodon and Lucania would be desirable for such places, and they are to be found everywhere in the ditches and tide pools on the flats. To add variety to the treatment of the subject, it might not be amiss to suggest that there is a fish, Anablaps, inhabiting the fresh waters of South America, which seems to be specially adapted to this purpose. To quote: ‘‘These small fishes swim at the surface of the water, feeding on insects, the eye being divided by a horizontal parti- tion into a lower portion for water use and a portion for seeing in the air.” Acting largely upon Mr. Seal’s advice, Dr. John B. Smith, the state entomologist of New Jersey, with Mr. Seal’s help, in November, 1905, brought Gambusia affinis and Heterandma formosa from North Caro- lina into New Jersey, which were distributed as follows: Eight thousand in spring and natural drainage rivulets flowing into the ice pond at Westville, N. J., 600 in a landlocked pond near Delanco, 600 in a mill pond between Merchantville and Evesboro, 600 in landlocked waters near Delair, and 4001in ponds of the Aquarium Supply Company, at Delair. In Doctor Smith’s report for the year 1906 it was stated that the experiment was to be written down a failure. Whether it was due to the destruction of the introduced fish by black bass, pike, yellow perch, and sunfish, or whether because of other enemies, or because of their dislike to their changed conditions, they found their way during * p *> oT Bae a amare ‘ ; vit pace 68 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. . the spring rains to rivulets flowing to the Delaware River, or whether they escaped in other ways, could not be told. In his report for 1907, however, Doctor Smith states that the Gambusia was found in large numbers in Teals Branch of Pond Creek, a small tributary of Delaware Bay at Higsbie’s Beach, by Mr. Henry W. Fowler, of the Academy of Natural Sciences, Philadelphia, and Messrs. H. Walker Hand and O. H. Brown. These gentlemen found it also very abundant in New England Creek, another tributary of Delaware Bay just north. Doctor Smith states that Mr. Seal was inclined to claim that this find- ing was the result of his work in 1908, but that Mr. Fowler doubted this conclusion since the points. here found were 90 miles distant from points of introduction. | FISH INTRODUCED INTO HAWAII TO ABATE MOSQUITOES. In the early part of 1903 Mr. D. L. Van Dine, then entomologist of the Hawaii Agricultural Experiment station of the U. S. Department of Agriculture, brought up the question of introducing top-minnows into Hawaii, since his investigations of the mosquito problem in the islands indicated that no effective natural enemies existed there. Dr. David Starr Jordan, to whom the problem was referred, informed Mr. Van Dine that while these fish had never been transported for such a great distance, they were extremely hardy, and that the experiment would be well worth while. The cost of the experiment, however, _ was prohibitive at the time, and it was not until 1904, when a Citi- zens’ Mosquito Campaign Committee was organized in Honolulu, that the requisite funds were raised. Mr. Alvin Seale, an assistant of the Bureau of Fisheries, United States Department of Commerce and Labor, was chosen to do the work, and with an advance of $500 started in July, 1905, from Stanford University to the southern United States. He proceeded to Seabrook, near Galveston, Tex., where he found top-minnows in large numbers. They were swarming in all the stagnant waters at sea level, as well as in various ditches, ponds, and standing pools. Mr. Seale found that mosquitoes were very plentiful about Seabrook, but after careful study he convinced him- self that they did not breed at all extensively in the bodies of water containing the fish, but in temporary and artificial breeding places, such as closed pools, tubs, and tin cans, not accessible to fish. Doctor Jordan had advised the collection of fish of the following genera: Mollinesia, Adinia, Gambusia, and Fundulus, all members of the family Peciliide, the top-minnows. Mr. Seale made careful exami- nations of the stomach conditions of the minnows of the genera recom- mended by Doctor Jordan., These stomach contents were found to consist largely of larve of various insects, including those of mos- quitoes, of the egg-masses of mosquitoes, of minute crustacea, and of some vegetation. The fish of the genus Gambusia were found to be PRACTICAL USE OF NATURAL ENEMIES OF MOSQUITOES. 69 _ the best insect feeders. The temperature of the water ranged from 74° to 87°F. Careful experiments were made with 10-gallon milk cans, in order to determine the conditions under which the fish could be most successfully transported to Hawaii. These experiments included observations on temperature of the water and on changing the water, and from these experiments was ascertained the necessary informa- tion in regard to the frequency of changing and the fact that best results could be obtained by transporting them in water of the normal temperature. The three most abundant species, Gambusia affinis, Fundulus grandis, and Mollinesia, were then collected and about — 75 were placed in each can, a 20-gallon tin tank full of water being taken along as a supply reservoir. Mr. Seale left Seabrook on Septem- ber 4, 1905. On the journey the fish were fed sparingly every morn- ing at 8 o’clock on prepared fish food, finely ground liver, or hard- boiled eggs. At half past nine one-half of the water in each can was drawn off from the bottom, thus cleaning the cans and removing un- eaten food and excrement. An equal amount of fresh water was added. At noon the cans were aérated by means of a large bicycle pump, a sponge being tied over the end of the hose to separate the air into fine currents. At four in the afternoon 2 gallons of water were drawn off from the bottom and 2 gallons of fresh water put in, and the aération was repeated just before bedtime. Careful tests of water at each place of changing were made by experimenting with two fish. At El Paso, Tex., there was so much alkali in the new water that the fish were killed; at Los Angeles and at San Francisco the water was good. Twelve fish died between Galveston and San Francisco, and 15 between San Francisco and Honolulu. Honolulu was reached on September 15, 1905, with a loss of 27 out of approximately 450 fish. On arrival the fish were placed in the breeding ponds prepared for them at Moanalua, near Honolulu, where four ponds had been made ready. The fish thrived i in all of the ponds almost equally well. They were protected by screens from predatory fish and from being carried out to sea by afreshet. In an official bulletin issued July 25, 1907, Mr. Van Dine reported that the fish had multiplied rapidly and from the few hundred introduced several hundred thousand had been bred and distributed. They had proved very effective against mos- quito larve and also against mosquito egg-masses. Later advices show that the good work is continuing, and the experiment seems to have been a great success. FISH IN THE WEST INDIES. Girardimus paciloides, a small top-minnow, occurs very abundantly in Barbados, where the popular name ‘millions’ ’ has been applied to them. This fish is very small in size, the grown female measuring about 14 inches in length, while the male is much smaller. The 70 PREVENTIVE AND REMEDIAL WORK AGAINST. MOSQUITOES. female is dull in color, without conspicuous markings, while the male is marked with irregular red splotches on the sides and has a circular dark spot on each side. The fish is a rapid breeder and thrives and multiplies in captivity in water-tanks, reservoirs, and fountains, and garden-tubs in which aquatic plants are kept. They are greatly used in this way both in the towns and on the estates to reduce the annoyance of mosquitoes. In 1905 this fish was introduced by the Imperial Department of Agriculture of the British West Indies from Barbados into St. Kitts, Nevis, and Antigua. In 1906 it was intro- duced into Jamaica and in 1908 into St. Vincent and St. Lucia, and into © Guayaquil in Ecuador. An account of these introductions is given in a pamphlet entitled ‘‘ Millions and Mosquitoes,” by H. A. Ballou, issued in 1908 by the Imperial Department of Agriculture of the West Indies (No. 55). In August, 1905, a number of fish were sent to Antigua in a kerosene tin. They arrived in good condition and were kept in a tank at the botanic station until they had sufficiently increased to be dis- tributed. They were liberated in several ponds and streams and increased so rapidly that the country board of health undertook the work of stocking all the ponds and streams of the island. Three years after the first introduction all of the more or less permanent | water of Antigua had been stocked, and Mr. Ballou states that many planters and others have commented on the apparent abatement of the mosquito nuisance in many localities. At St. Kitts the intro- duction was equally successful, but the local government did not take ‘up the distribution of the fish as in Antigua. In Jamaica they were established with good results. ‘‘Millions’”? may be fed in captivity on mosquito eggs and larve, on raw beef or hard-boiled eggs, upon small insects of any kind, and even upon corn meal. They are readily transported short distances in a kerosene tin with no other preparation than a wire netting arranged near the top to prevent the fish from being thrown out if the water is splashed about. These fish have been introduced at the Isthmus of Panama. FISH IN GERMAN EAST AFRICA. Mr. J. Vosseler, in an article entitled ‘‘Fische als Moskito-Vertil- ger,’ gives an interesting account of some experiments with mosquito-feeding fishes inGerman Hast Africa. He discusses the ques- tion quite as authoritatively as does Mr. Seal, already quoted, and brings out the point that on account of the great physical and chem- ical differences in the water inhabited by mosquito larve the selection of suitable species of fish is made difficult by several restrictions. He states that the shallow shores of rivers or large lakes can be ex- cluded from consideration, since the young of most species of fish aPublished in Der Pflanzer. Ratgeber fiir Tropische Landwirtschaft, for June 13, 1908, vol. 4, No. 8, pp. 118-127. Ee ee PRACTICAL USE OF NATURAL ENEMIES OF MOSQUITOES. 71 living there frequent the shores in shoals and prey upon the various forms of animal life, mosquito larve included. Many water supplies, however, contain salt and other chemicals, and are polluted from various sources, even from the excrement of game coming to drink; while temporary collections, such as pools, puddles, and irrigation ditches, contain turbulent, muddy water. The level of the water in these different conditions is very variable, and the temperature of the water goes through great variations within a single day, often in midday the heat rising above the limit which most fishes can stand. A fish which would withstand all these conditions would be very exceptional. While we are considering the question of fish intro- duction, the adaptability of the species to acclimatization, its power of enduring long transportation, and its ability to multiply rapidly, even under adverse conditions, are of vital importance to success. In his travels through the land of Oram (Algeria) in 1892, Mr. Vosseler found a widely distributed species occurring in thousands not only in the springs of salt or magnesia water as well as in the irrigation ditches, but also in the highly polluted, badly smelling pools used to water camels, in which 300 to 400 camels often waded in one day. - He found the same species afterwards in pure fresh water, in hot springs, and in brackish water. He also found that it inhabits the subterranean waters of the desert and is probably brought up by boring for artesian wells. One of the officers of the garrison situated in the midst of a salt basin without outlet pointed out to Mr. Vosseler that this little fish eats mosquito larve, which explained the com- parative absence of mosquitoes in that locality. Mr. Vosseler at- tempted the introduction of these fish into Germany and succeeded very well in spite of inadequate preparation. They began to lay eges within a week of their arrival, and have become accustomed to proper food. They always prefer mosquito larve and small crusta- ceans. The fish in question is Cyprinodon calaritanus. The female is 8 centimeters and the male 5 centimeters long. The eggs are attached singly to water plants or stones at the rate of one or two a day. Mr. Vosseler states that the excellent qualifications of the species are shared by other members of the same family. In German Kast Africa at least 2 genera and 5 species are known. | A BRAZILIAN FISH. Excellently practical results are reached in Rio de Janeiro by the use of a small fish known as the ‘‘barrigudo”’ (Girardinus caudima- culatus) which, in the great prophylactic work carried on in that city under the public-health service, is placed in tanks and boxes where it is impossible to use petroleum, and devours the larve of mosquitoes most voraciously. 72 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. MR. THIBAULT’S OBSERVATIONS. In considering the normal relation between mosquitoes and fish, Mr. James K. Thibault, jr., of Scott, Ark., in a recent communica- tion presents some interesting views and steer an nie instance which he considers ty pical 1 in some localities: | Personally, I do not think that mosquitoes ever breed in the presence of fish if the water is open, allowing the fish free access to the larve, yet it is a matter of common observation that under certain favorable circumstances some species do breed regu- larly in streams where fish are abundant. Yet even where conditions are favorable only a very few species seem to take advantage of it. So far as my own observations go the only mosquitoes that regularly do so in this locality are Anopheles quadrimacu- latus and Culex abominator. Conditions are favorable when the surface of the water becomes carpeted with aquatic vegetation which restrains the fish in their movements yet allows ample room and protection for the larve of the above-named species. There is a certain deep, slowly running bayou here that is the main breeding place for quadrimaculatus and abominator at present, while two years ago not a larva could be found there atall. The explanation is simple and may be given as a typical example of its kind. Two years ago launches passed through this bayou daily and all logs and drift were removed as soon as found so that the water had free passage and the pondweeds found no foothold, except very near the banks where they were completely destroyed by stock. After the launches stopped passing through this bayou logs soon accumulated and the pond- © weeds immediately took possession, so that throughout the present season quadrimacu- latus and abominator have bred continuously and abundantly in this bayou. It must be noted in passing that the larve, pupe, and freshly emerged adults bred in such a location are invariably bright grassy green in color, which gives them an additional advantage over the fishes. This is not the case with larvee, etc., found in other places. DESTRUCTION OF LARVZ. Of course the abolition of accidental breeding places, the under- taking of drainage measures, and the practical use of natural enemies such as fish, result in the ieeacneen of larvee, but in this section it is proposed to treat of those measures which Oo the use of what have come during recent years to be termed ‘‘larvicides.”” The dic- tionary definition of the word insecticide is ‘‘one who or that which kills insects, as insect powder;’’ therefore a definition of larvicide would be one who or that which kills larvae. But in mosquito work it has come to be used for those substances which are applied to bodies of water in which mosquito larve are living, and which result in their destruction in one way or another. These substances, for the most part, are either poisons or more frequently oils which, forming a surface film, destroy the larvee when they come to the surface to breathe. Ronald Ross long ago pointed out the great desideratum in this direction in the following words: I have long wished to find an ideal poison for mosquito larve. It should be some solid substance or powder which is cheap, which dissolves very slowly, and which when in weak solution destroys larvee without being capable of injuring higher ani- ' DESTRUCTION OF LARVZ. 73 mals. What a boon it would be if we could keep the surface of a whole pond free from larvee simply by scattering a cheap powder over it, once in six months or so. It is very possible that such a substance exists, but unfortunately we have not yet discov- ered it.¢ _ A great many experiments have been tried with poisonous sub- stances in the search for the desideratum described by Doctor Ross, but although it is now seven years since he wrote this paragraph we still have failed to discover it. As early as 1899 Celli and Casagrandi published an account of an elaborate series of laboratory experiments on the destruction of mosquitoes by various chemicals in a paper enti- tled ‘‘La Distruzione delli Zanzare,”’ published in the Annali d’Igiene Sperimentale. These experiments resulted in little practical good, and practically the best of all the larvicides, namely, the petroleum products, were discredited by the authors in question. In the last few years many substances have been experimented with, both in the United States and in other parts of the world, and. there has been from time to time a newspaper notice, or a series of newspaper notices, of some new substance which careful experimen- - tation has shown to be of little or no service. In this way the use of permanganate of potash received much advertising in 1900, but as the writer has elsewhere pointed out, as a result of careful experi- mentation it was found that small amounts of the chemical have no effect whatever upon mosquito larve, which were, however, killed by using amounts so large that instead of using a handful to a 10-acre swamp, as had been stated in the newspapers, at least a wagon load would have to be used to accomplish any result; moreover, twenty- four hours after the use of this large amount and after the larve were killed, the same water sustained freshly-hatched mosquito larve per- fectly, so that even were a person to go to the prohibitive expense of killing mosquito larvee in the swamp with permanganate of potash the same task would have to be done over again two days later. In 1904 a publication by the Bureau of Plant Industry of the United States Department of Agriculture, on the use of sulphate of copper against aloze and other microscopic plant-life, put certain newspaper men, on the wrong track, and a number of articles were published making the erroneous statement that the Department of Agriculture recommended sulphate of copper as a perfect remedy against mos- quito larve. So widely was this alleged discovery heralded that careful experiments were at once made in the Bureau of Entomology, by Dr. John B. Smith, of New Jersey, by Dr. W. E. Britton, of Con- necticut, and by other entomologists, with the result that thesubstance ~was found to be of very slight value as a larvicide, and of really no practical value whatever. Several proprietary mixtures or mosquito compounds have been prepared and placed on sale for the purpose of destroying mosquito @ Mosquito Brigades, London, 1902, pp. 33-34. 74 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. larve. A number of these have been brought or sent to the writer for experimentation, but, considering the cost, none of them has been of as great practical value as petroleum. In his report on the mosquitoes occurring in the State of New Jersey,? Dr. John B. Smith describes a number of experiments with substances of this kind, nota- bly with certain soluble carbolic acid and cresol preparations, with chloro-naphtholeum, and with phinotas oil, and in his report for 1907 he gives the results of certain experiments with a substance known as ‘‘killarve.’’ It is not necessary, however, to consider any of these substances in this connection except to state that phinotas oil has met with considerable use, since it forms a milky compound with water which settles through a pool and destroys not only mosquito larva, but all other animal life in the pool. It is used in cesspools and recep- tacles of that kind, and is also found to be of service in the anti- mosquito work on the Isthmus of Panama. In another section we have spoken of the use of certain aquatic plants as forming so dense a covering over the surface of the water as to exclude mosquito larve from access to air, thus bringing about their destruction. Another method which brings about the same results, although in a different way, is described by Consul Wm. H. Bishop, of Palermo, Sicily, in the Monthly Consular and Trade Reports, No. 331, April, 1908, in which he quotes from an account of the experiments made by the chief of the sanitary service at Gaboon, French Africa, with cactus as a substitute for petroleum in the extermination of mosquitoes in warm climates. Beyond this account by Mr. Bishop we have no further information of this remedy: The thick, pulpy leaves of the cactus, cut up in pieces, are thrown into water and macerated until a sticky paste is formed. This paste is spread upon the surface of stagnant water, and forms an isolating layer which prevents the larve of the mosqui- toes from coming to the top to breathe and destroys them through asphyxiation. Itis true that petroleum can do the same service, but in warm climates petroleum evapo- rates too quickly and is thus of little avail. The mucilaginous cactus paste, on the contrary, can hold its place indefinitely, lasting weeks, months, or even an entire year; and the period of the development of the larve being but about a fortnight it has the _ most thorough effect. After all we are practically reduced to the use of oils in this kind of work. Some effort has been made to find if there are any other oils that could be used to better advantage than petroleum. A suggestion was once made by Mr. W. J. Matheson that corn oil might be used. This is a substance which is made rather extensively in certain parts of the country and which, considering the enormous crops of corn grown in Western States, which in fact are so great that in past years of overproduction corn has been burned as fuel, might reasonably a Report of the New Jersey State Agricultural Experiment Station upon the Mos- quitoes Occurring within the State, their Habits, Life History, etc. Trenton, N. J., 1904. aah etal te hy de i aie § 4 j tet ee ee eee, DESTRUCTION OF LARVA. 15 be supposed to be a cheap oil. This, however, is not the case, and its price is prohibitive as compared with ordinary grades of kerosene. Experiments undertaken in 1900 indicated that corn oil does not spread readily. It gathers together in large patches on the surface of the water, and mosquito larve rising to the surface and finding themselves under a patch of oil will simply wriggle violently until they _ find the spaces between the patches where they breathe comfortably and live for several days. In this experiment the object was not only to secure a cheap and efficient oil, but to secure a persistent oil which will not evaporate and which will remain for at least several weeks over the surface of the water. Its nonspreading qualities, however, as well as its price remove it from practical consideration. To sum up the whole question of larvicides, nothing has been found more satisfactory as regards efficiency and price than common kerosene of low grade, or better still, that grade known as fuel oil. This conclusion has not only been arrived at in the United States, but elsewhere, although petroleum has been more extensively used in the United States than elsewhere, and it is better understood in this country. In choosing the grade of the oil, two factors are to be considered. First, it should spread rapidly; second, it should not evaporate too rapidly. The heavier grades of oil will not spread readily over the surface of the water, but will cling together in spots and the coating will be unnecessarily thick, as in the case of the corn oil just mentioned. The rapidity of spread of film is also important. Ronald Ross, in his ‘‘Mosquito Brigades,’ pages 34 to 35, makes the following statement: Mr. Hankins of Agra informs me that the addition of amyl alcohol greatly expedites the formation of the film; and it is very necessary to obtain a film which makes its way between the stalks and leaves of water weeds. Early in the course of antimosquito work in the United States careful experiments were made by Mr. W. C. Kerr, in the work of the Richmond County Club, on Staten Island, to which we have referred before. He tried several grades of oil and found a low grade of oil known as “‘fuel oil” to be best adapted to the work. Of the oils which he tried, some contained too much residuum of a thick nature, which appeared as a precipitate and could scarcely be pumped; some were too thick in July weather and could not be _pumped at all, while some were limpid, easily handled, made a good uniform coating on the ponds, and were very effective. So long as oil flows readily and is cheap enough the end is gained, provided it is not too light, and does not evaporate too rapidly. The grade known as light fuel oil was recommended by the writer to the United States army workers in Cuba at the close of the Spanish war and was found to be effective. The price of oil of this kind has varied from $2.25 per barrel to $3 per barrel, f. o. b. Philadelphia. 76 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. In his early Catskill Mountains experiments the writer ascertained that about an ounce of kerosene to 15 square feet of surface space is about the right proportion, and that such a film would remain per- sistent for ten days, or slightly longer. He noticed further that even after the iridescent scum had apparently disappeared there was still — an odor of kerosene about the water and that adult a avoided it. In the work done by Mr. H. J. Quayle, near San Francisco* more or less oiling was done upon ponds that could not be drained, and upon standing pools remaining in creek beds during the summer; and some was also done on marsh lands. The oil used was a combi- nation of heavy oil of 18° gravity, and light oil of 34° gravity in the proportion of 4 to 1, respectively. This mixture made an oil that was just thin enough to spray well from an ordinary spray nozzle, and yet was thick enough to withstand very rapid evaporation. It was applied by means of a barrel pump where this could be used, but in the creeks and other situations, which could not be reached by horse and wagon, the ordinary knapsack ee was used. The price of the heavy oil at Burlingame, Cal., was 2 cents a gallon, and of the lighter oil 24 cents a gallon. The pee was obtained from the Bakersfield district, while the latter was a product of the Coalinga fields. Mr. Quayle found that the duration of efficiency depended somewhat on the nature of the pool and its exposure to the winds, but in no case could it be counted upon as thoroughly effective after a period of four weeks. This period of four weeks brings up the question as to the fre- quency of application of kerosene. The persistence of the oil will undoubtedly vary with the temperature and with the character of the pool—whether exposed to the direct rays of the sun or shaded by trees, or exposed to the wind. Three weeks will probably be a good interval with light fuel oil. The army of occupation in Cuba — used its oil every two weeks. The application of kerosene to the surface of the water can 1 be made in any one of several different ways. If it is simply poured upon the surface it will spread itself, or will be spread rapidly by light winds. The spraying method, either witb the barrel pump, or by knapsack pump, or bucket pumps, has been frequently used. The writer watched the oiling of ponds with a spraying pump in a— New Jersey town several years ago. The water treated was all in small woodland ponds, and there was a great waste of kerosene. The spray was diffused and became scattered over the vegetation on the borders of the pond, a large share of it being wasted in this way, while the shore vegetation was killed. On small ponds the oil aBul. No. 178, Agr. Exp. Sta., Univ. Cal., 1906. oe ee ee PE mtg ti mene lt DESTRUCTION OF LARVA. 77 can be sprinkled to advantage out of an ordinary watering pot with a rose nozzle or, for that matter, pouring it out of a dipper or cup will be satisfactory. In larger ponds, pumps with a straight discharge nozzle may be used: A straight stream will sink and then rise and spread until the whole surface of the pond can be covered without waste. The English workers in Africa advise mopping the petroleum upon the surface of the water by means of cloths tied to the end of a long stick and saturated with kerosene. The use of such a mop may be desirable, even where a straight discharge pump has been used, in order to commingle two or more surface sheets of oil. In some of his early work on Staten Island, Doctor Doty, the health officer of New York, used a pump with a submarine discharge, throwing the oil out at the bottom of a pool and allowing it to rise to the surface. It seems that the idea was to destroy the insects feeding at the bottom more quickly, but as most mosquito larve rise to the top to breathe about every minute, there is practically nothing to be gained by such ~ amethod of distributing kerosene. The use of larvacides in tropical regions brings in certain new fea- tures which complicate the problem of mosquito destruction to a cer- tain extent. Colonel Gorgas and his corps of workers at Panama have been using petroleum very extensively just as they did at Habana. They find, however, that at Panama the rapid growth of vegetation prevents the oil from spreading uniformly and that it can not make a thin uniform film over the surface of water in which vegetation grows. ‘They find also that algz on the surface of the waters form with the oil a dark scum, which collects at the bottom of shallow pools. This scum later breaks up and floats about on the surface, rendering succeeding oilings less efficacious and necessitating the use of larger quantities of oil. They also find. that where vegetable débris collects in a large body of water it will be blown about as a mass, its location changing with the wind, and thus break the film of oil. Mosquito larve also hide in this vegetation, which protects them from fish. The wind blows the oil to one side of the surface and it evaporates very rapidly in the Tropics. During the rainy sea- son it is washed away very rapidly before it destroys all of the larve and of course where the film is not perfect the larve find free places to breathe. The bulk of the oil and the cost of transportation in _ rough territory for work on a large scale are disadvantages. In their work they find that they must constantly occupy themselves in removing vegetation before oil is applied, in order to prevent the _ necessity of using excessive amounts of oil. They find that new growths of alge appear to develop very rapidly after the oil has united with the previous crop and sunk to the bottom. In the course of the Panama work, as previously stated, phinotas oil has been used, and has been found to have the following advan- 78 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. tages over crude oil: It acts as a poison and kills the larve very rap- idly. It brings the larve out of their hiding places at once and is useful as an aid to the detection of the presence of mosquito larve. It is found also that in continuous heavy rains the larve are killed by the phinotas oil before the rain dilutes the treated water to any great extent. They find, however, that phinotas oil has certain dis- advantages: It kills fish in a solution of 1 to 5,000, and it loses its efficiency very soon after application, so that eggs are laid upon the treated water quickly and the larve develop. Doctor Gorgas points out that there is considerable variation in the quality of this substance as shipped to the Isthmus. Some barrels will kill larve quickly in a solution of 1 to 3,000 parts of water, while other lots require for the same results 1 part to 1,000. Doctor Gorgas has recently published a list of the desiderata for the perfect larvacide for use in the Tropics, agreeing with the opinion expressed by Ronald Ross when he re- turned from his first visit to Africa that nothing as yet known is per- fectly satisfactory : (a) Low ultimate cost. (b) Ability to affect and kill mosquito larve promptly, the more rapidly the better. It must be effective in moving water as well as in still water. (c) Ability to form a solution with water and to thoroughly diffuse and mix with all the water of a small pond if applied only to one part thereof. Also the substance must not lose its larvicidal properties for a week or more after its application. The longer it will retain its larvicidal properties after it has been placed in the body of water the more valuable it will be. (d) Ability to diffuse in water and through all parts of a body of water such as in a pond containing grass, water lilies, other aquatic vegetation, and vegetable débris. (e) Ability to kill green alge promptly. (f) A concentrated larvicide is necessary so that one part of it to five thousand or more parts of water will promptly kill mosquito larve and pupe. (g) Nonpoisonous to human life or animals when taken in a strength of 1 to 1,000 and accidentally used as drinking water. (h) That it have the property of discoloring the water to which it is applied, or of giving off sufficient odor to induce persons not to use water containing it in solution for drinking purposes. (i) That the odor, if present, be not so obnoxious as to make its presence in water in ponds or streams near habitations undesirable. (j) That it shall have a safe flash test and be nonexplosive. (k) That it shall be sufficiently stable so that it may be kept “‘standardized.’’ Decoctions and emulsions of Derris uliginosa have been recom- mended for larvicidal use, but experiments conducted at the Well- come Research Laboratories at Khartoum show that while it has con- siderable potency it also kills fish, and that even in regions where these plants are native the different species of Derris have only a limited use as insecticides. During the 1905 outbreak of yellow fever in New Orleans an at- tempt was made to destroy mosquito larve in the open gutters of the city by the use of common salt. Dr. H. A. Veazie wrote us that DESTRUCTION OF LARVA. 79 the results were good where the work was properly done. Shortly after operations were begun there was a flight into the city of Aédes sollicitans from the salt marshes northeast of New Orleans. Indig- nant citizens, ascertaining from experts the name and habits of the species, jumped to the conclusion that salting the ditches had brought about suitable breeding conditions for sollicitans and that the invasion of the city by that species was a direct result of the work of the sani- tary officials. Charging mosquito pools with electricity does not seem to have been tried. Mr. Aaron Aaronsohn, director of the Jewish agricultural experiment station at Haifa, Palestine, tells the writer that Professor Blasius, of Berlin, reading a newspaper account - that some electrical workers engaged in the vicinity of a river used the electrical current to catch fish, began, some little time ago, to study the effect of electricity on fish, and that he found that by discharging a, current into the water he could stun the fish, but did not kill them. Mr. Aaronsohn suggests that this plan may perhaps be tried to advan- tage in certain favorably situated localities to ascertain whether it can be practically used against mosquito larve. In the course of the experimental work with larvicides carried on at the Isthmus of Panama Colonel Gorgas and his assistants have con- structed a larvicide plant at Ancon, and in the August, 1909, Report of the Department of Sanitation of the Isthmian Canal Commission it is stated that 14,600 gallons of larvicide were made at a cost of $0.1416 per gallon. The following is quoted from this report: The method of making same is as follows: 150 gallons of carbolic acid is heated in a tank to a temperature of 212° F.; then 150 pounds of powdered or finely broken resin is poured in. The mixture is kept at a temperature of 212° F., 30 pounds of caustic soda is then added and solution kept at 212° F. until a perfectly dark emulsion, with- out sediment, is obtained. The mixture is thoroughly stirred from the time the resin is used until the end. The resultant emulsion makes a very good disinfectant or larvacide. In fact, 1 part of it to 10,000 parts of water will kill Anopheles larve in less than half an hour, and 1 part to 5,000 parts of water will kill Anopheles larve in from five to ten minutes or less. This property of killing larve rapidly is of great importance in the Tropics, where continuous rainy periods make crude oil or kerosene much less valuable as a larvicide than it is in northern latitudes having less rainfall. Also, the larvicide acts as an algicide, and thus destroys the food and the hiding places of Anopheles larve. Asit takes up very little room, compared with the area it can be spread over, the cost of distribution will be much less than that of crude oil or kerosene. Consider- ing the large territory which the antimalarial work covers, this item alone is of great financial advantage to the department. Tests have recently been made to determine approximately how much of the new larvicide will be needed per month (rainy season) for each district. - _ Although this larvicide will be used to a large extent, yet we shall continue to use crude oil for streams having a fair velocity, as such application gives excellent results and is as economical as larvicide would be, as the oil is spread in a very fine film automatically. In order to make the crude oil drip with continuous regularity, a piece of metal similar to that part of a flat-wick lamp which holds the flat wick is fastened to the oil container. It is made somewhat larger than the wick, so that the 80 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. wick fits it loosely when saturated with the grade of fuel oil we use. This metal wick chamber is fitted to the oil container about 3 inches from its base. The space below the wick chamber is filled with a solution of caustic soda or of larvicide. As the oil is attracted along the wick by open, attraction, it comes into contact with the larvicide or caustic soda and is “cut’’—rendered thinner. This method of procedure prevents the wick from being clogged by the thick fuel oil and a ik the wick to drip the oil desired. In the September, 1909, report it is stated that the new «havent was giving very satisfactory results and would undoubtedly reduce the cost of antimalarial work, besides being more effective than crude oil in many places. It seems to have some value as a destroyer of vegetation. In the October report satisfaction with its use is again expressed, and it is stated that the fact that it kills the grass at the edges of the ditches will be of importance in reducing the cost of antimalarial work. ORGANIZATION FOR COMMUNITY WORK. While in a large measure it is true that every individual house- holder practically rears upon his own premises the majority of the — mosquitoes that bother him, still in a closely built city those reared by one’s neighbors must be taken into consideration. In isolated country houses the character of the adjacent region must be con- sidered by the individual who concerns himself with this work, but even here some sort of an organization is desirable, and even fre- quently necessary, as in cases where swamp lands are to be drained or where occasional invasions of such a migratory species as Aédes sollicitans are to be feared. The control of all sources of mosquito supply in case of fresh water or brackish swamp land is usually too great a task for the individual, although on the large estates of great proprietors such work has been done at individual expense. In any sort of community, however, organization is necessary, not only to carry out the actual work, but to produce and to emphasize a uni- versal sentiment in favor of the mosquito crusade—a sentiment so strong and so general that every individual will cheerfully take part in the work: The pioneers in this country who, in 1901 and 1902, attempted to arouse such a public sentiment had much difficulty in educating the people and in securing funds, but lately it has been an easier matter. Many communities, large and small, have taken up antimosquito measures, and such large cities as New York, Balti- more, New Orleans, and Nashville have given the question serious © consideration in their city councils and in their boards of health, and have entered upon measures of greater or less efficacy. Many smaller towns have begun the crusade also, and those which have been espe- cially active have been communities of summer resort. One of the early attempts was the formation of the North Shore Improvement Association of Long Island, which undertook a mosquito campaign yetelee. = or lee ane oe’ ORGANIZATION FOR COMMUNITY WORK. $1 involving over 25 square miles of territory along the north shore of Long Island, the territory including several villages and many country homes of wealthy people. Following the first year’s work of this association a national antimosquito society was formed to encourage just this kind of work, and this society has published instructions and pamphlets of information which are at the disposal of all com- “munities desiring to enter upon the task of freeing themselves from mosquitoes. _ Work of this kind carried on in Cuba, in Panama, and in various English colonies will be referred to in later sections. All have been _ well organized and actively carried forward and have been successful _ inreducing the number of mosquitoes and in correspondingly reducing such diseases as are carried by mosquitoes. Theoretically, community work should be done under official auspices, and should be inaugurated by boards of health, but official action is slow, even in the United States, where there is, as a rule, less red tape than in older countries. Moreover, official action in sanitary measures is often conservative, as well as slow. As already pointed out, the health question is not the only one involved. Abun- dance of mosquitoes means enormous economic loss to a community, entirely aside from the important question of health, and individual property owners realize this more than do official bodies. It is only necessary to cite the increased value of real estate at summer resorts where the mosquito scourge has been wiped out, and the great value of reclaimed marsh land for manufacturing sites in the immediate vicinity of great cities, or for agricultural purposes at a greater distance from the great centers of population. An unusual reason for anti-mosquito work developed a few years ago. A famous sports- man, who was at the same time a captain of industry and had also been a cabinet officer at Washington, spent large sums of money in the vicinity of Sheepshead Bay, Long Island, to reduce the abun- dance of mosquitoes, because his blooded race horses were losing condition from their bites, although he had previously paid no atten- tion to the mosquito problem from the standpoint of human health and convenience or from the standpoint of the value of the real estate in that vicinity, of which he was a large holder. In community work, therefore, as well as in most other measures of reform, the organization of private citizens has usually been the initial step. Many communities have their own village or town im- provement associations, and many cities have their citizens’ asso- ciations constantly alert to discover needed reforms and improve- ments and to bring them emphatically to the notice of their elected representatives on the city council and to the mayor’s appointees on the board of health. It is through the mosquito committees of such associations that very much of the work in this direction has 37713—Bull. 88—10——6 82 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. been agitated and inaugurated, and doubtless this method will con- tinue most effectively for some time to come. _ The first step in undertaking such work is to interest several responsible persons whose names carry weight in the community, and then to raise a small fund, either by appropriations from funds at the disposal of the improvement society, or whatever it may be, or by private subscription. Then these persons, forming a com- mittee, should issue a circular to every householder, signed by the whole committee, reciting very briefly the well-known facts concern- ing the breeding places of mosquitoes and the measures which should at once be taken by householders. A good plan also would be to have a public lecture given by some expert, well illustrated, to which all householders should be invited. An excellent circular of the character just described was issued in the early summer of 1901 as follows: | THe VILLAGE IMPROVEMENT Society oF SOUTH ORANGE. SOUTH ORANGE, N. J. May 27, 1901. The breeding place of the mosquitoes that may infest your house may be looked for within your own house or grounds, or in your immediate neighborhood. ‘The mosquito lays its eggs only upon standing water and passes the first ten days of its existence in the water. Without standing water there can be no mosquitoes. Dr. Howard says: ‘‘I feel sure that the cesspools in South Orange must be responsi- _ ble for a great deal of your mosquito supply.’’ Therefore: Look to your cesspools, cisterns, water tanks, and any barrels or other receptacles in which water may stand for a few days, either inside or outside the house. It is suggested that you at once do away with every unnecessary water receptacle. Put kerosene oil in your cesspools and on surface of necessary ghia == water once in three weeks. Oil placed on surface should not affect the taste of water drawn from beneath the surface, but when that is not considered advisable water receptacles should be ee with a fine mesh screen. The mosquito being not only a serious annoyance, but a constant menace to health, its extermination becomes a matter of public concern. The cooperation of every household is requested. Please Teport to-s2 28s: Wah ee eS the location of any pools of stagnant water in your neighborhood. After the issuing of the circular or the holding of the public lecture, or both, if the members of the committee are too busy, as they are likely to be, to engage to any extent in the actual superintending work, an intelligent superintendent must be chosen who will famil- iarize himself with the biology of mosquitoes and especially with the character of mosquito breeding places in general. He should at once be put to work upon a survey of the mosquito topography of the neighborhood. It will be well for him to make a map upon which every breeding place, aside from the chance receptacles about ee ee i a eg eee ee ORGANIZATION FOR COMMUNITY WORK. 83 houses, should be noted with the greatest accuracy and care. Every house having an uncovered water-tank or having rain-water barrels should also be noted, and for each locality the most effective as well as the most economical remedy should be recorded. If these reme- dies demand any large-scale work, estimates of the necessary expen- ditures should be indicated. Such a careful report and map having been prepared and placed in the hands of the committee the amount of funds necessary can readily be estimated, and the expenditure of such sums as it is found possible to raise can be considered and agreed upon. The work can then be easily carried on through the summer under the direction of this superintendent, and of course the amount of the expenditure and the number of employes will depend entirely upon the local mosquito-breeding possibilities. Some small communities will find that a full understanding of the problem on the part of individual householders will bring about great relief as the result of individual work, and that the only organ- ization necessary will be perhaps the signing of a pledge by indi- viduals to take care of their own premises. In other communities the matter will be a little more serious, but there will be some where the employment of a single man for two or three days a week through- out the summer will result in freedom from mosquitoes. Again, however, in larger communities the enforcement of municipal regu- lations will be found to be necessary before a desirable result can be obtained, and where the village is built upon swampy land or is sur- rounded by swamps the expenditure of considerable sums of money will be found to be imperative. In every community, however, there will pretty surely be ultra- conservative, recalcitrant, and ignorant citizens—people who will not take the trouble to prevent the breeding of mosquitoes on their own premises—people in fact who will violently object to the en- trance on their premises of an individual who will do the work for them. Such cases are not numerous, but they are always difficult to handle, and, in the absence of municipal action, moral suasion must be tried in the most ingenious ways which the committee can devise. Dr. Ronald Ross, in his excellent work ‘‘ Mosquito Brigades,”’ in writing of such persons, puts it very happily in the following words: The qualities chiefly necessary [in a superintendent] are energy, persistence, and an entire indifference to public or private opinion. The need of the first two is obvious; that of the last requires some explanation. The self-appointed superin- tendent will be at once astonished, and perhaps alarmed, at finding that his philan- thropic and wholly harmless efforts are met at the outset by a storm of letters to the local press, demonstrating the absurdity and even immorality of his intentions; prov- ing that mosquitoes cannot be destroyed, that they spring from grass and trees; that they can be destroyed, but that it is wicked to make the attempt because they were created to punish man; that they do not carry malaria, because malaria is a gas which 84 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. rushes out of holes in the ground, and rises as a blue mist over the country; they do not carry yellow fever, which is due to the effect of the tropical sun on rotting vegeta- tion; that they do carry malaria and yellow fever, but in such small quantities that they act beneficially as unpaid vaccinators of these diseases; and so on.@ It is possi- ble to ignore all such epistles, because where they do not contradict each other, some one else is sure to contradict them; but an occasional letter in reply does good, and, to speak practically but rather cynically, serves to stimulate the necessary public interest in the work by keeping the letter-writers at such a pitch of exasperation that they give the campaign a constant stream of gratuitous advertisement in the news- papers. We are permitted to be cynical in a good cause. Fortunately, operations against mosquitoes can be conducted on a large scale without much reference to private opinion—fortunately, because the inertia of the masses regarding new pathological discoveries is so great that were we to depend upon con- verting them, nothing would be done for half a century. For some inscrutable reason the man in the street, though he would scarcely think of contradicting a lawyer or an engineer on matters of law or engineering, finds himself quite equal to exposing the absurdities of the whole medical faculty on a medical matter. These operations require no sacrifices or cooperation on the part of the general ill. Most householders are glad enough to have their mosquito larve destroyed, and their backyards cleaned up for nothing. The reader, therefore, if he sees fit to start the work we are considering, may quietly proceed in it undisturbed by criticism, and may calculate upon receiving not only as much public support as his work will require during its progress, but the thanks of his fellows at its termination. Indeed, the majority of the public will not be slow to recognize the value of his efforts, even if they do not understand the scientific reasons which have induced him to make them. In community work, after making an effort to insure the absence of household breeding, the attention of the superintendent should be - devoted to chance pools along the public roadway and to breeding places in unused land. Drainage or filling are the best measures to adopt. The superintendent will find it advisable to attempt first to extirpate those breeding places from which the greatest numbers of mosquitoes are issuing. In this way he will the sooner bring about an appreciable diminution of the number of the insects, and of course the sooner this diminution is noticed by the citizens the sooner will popular sentiment unanimously support the work. The less populous breeding places may await treatment until a later date. | Large-scale operations requiring a considerable expenditure of money must be organized very perfectly as to detail. The first example of this large-scale work done in the United States was carried on in the most intelligent way by the North Shore Improvement Asso- ciation of Long Island, mentioned above. Here, as an initial step, work was done by the superintendent and engineer, Mr. H. C. Weeks, during the summer of 1901. Mr. Weeks completed the survey of the large territory and estimated the cost of all operations. Another survey was made by two biologists, Prof. C. B. Davenport and Mr. F. E. Lutz, of the Cold Spring Harbor laboratory, then of the Brooklyn Institute of Arts and Sciences. These gentlemen positively a Notr.—Dr. Ross states that he has seen every one of these statements, and many others equally absurd, made at least half a dozen times in the British press. ae ane eS ES —— ORGANIZATION FOR COMMUNITY WORK. 85 identified all breeding places. Still another survey was made by the late Prof. N.S. Shaler, of Harvard University, who advised concern- ing the best methods of reclaiming the salt marshes included in the territory where the brackish-water mosquito breeds. Upon the basis of these surveys and reports the association began in 1902 its active work of extermination. The following is Doctor Ross’s summary of antimosquito work, and it is so admirable that it is quoted in full: SUMMARY. 17. Summary of objects: (1) We do not propose to exterminate mosquitoes in any entire Continent. We propose only to deal with them in the town in which we live, and in its suburbs. (2) We do not propose to get rid of every mosquito even in this town. We aim only at reducing the number of the insects as much as possible. (3) We do not think it possible to drain or otherwise treat every breeding-place in the town. We aim at dealing with as many as possible. (4) We can not exclude mosquitoes which may just ee be blown into ihe town from miles away. We content ourselves with preventing the insects breeding in the town itself. 18. Summary of methods: (1) We start work at once with whatever means we can scrape together. (2) We operate from a center outward. (3) We clear houses, back yards, and gardens of all rubbish; empty tubs and cisterns containing larve, or destroy the larve in them by means of oil. (4) We show people how to do these things for themselves, and how to protect tubs and cisterns by means of wire gauze. (5) When we have cleared as many houses as we determine to deal with, we clear them over again and again. (6) We fill up or drain away all the pools, ditches, old wells, and puddles we can— especially those which contain most larvee. (7) Such pools as can not be filled up or drained are deepened and cleared of weeds if they contain larve. (8) Streams and water courses which possess larve are ‘‘trained.”’ (9) Where we can do nothing else we destroy the larve periodically with oil, or by brushing them out with brooms, or by other means. (10) We endeavor to interest our neighbors in the work, and to educate the town into maintaining a special gang of men for the purpose of keeping the streets and * gardens absolutely free of stagnant, mosquito-bearing water. . 19. Motto: Our motto should be one which I think will shortly become the first law of tropical sanitation, namely, ‘‘ No Stagnant Water.”’ After concluding an account of his own personal work at Lloyds Neck, Long Island, and of the work done by the North Shore Improve- ment Association, Mr. W. J. Matheson, speaking before the First Anti-Mosquito Ghaveition in New Yorks December 16, 1903, con- ‘cluded that as the result of the work carried on it had been demon- strated that, with the exception of the salt-marsh mosquitoes, the mosquito nuisance can be controlled and abated in almost any locality where intelligent cooperation can be secured and a systematic inspec- tion made of the premises for the purpose of destroying the breeding 86 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. places. Extermination, in his opinion, will exterminate just as far as the intelligent landowner is willing to carry it, but that it can not be done once and for all any more than weeding a garden or the cropping of a lawn can be done once and for all. He concludes his paper with the following words: So far as my experience goes, it has been demonstrated that mosquitoes can ie as completely exterminated in any locality as dirt can be swept from a building, or as weeds from a walk, with the possible exception of Culex sollicitans, and with the exer- cise of no more intelligence and much less labor than is required in the performance of many domestic duties. My experience would lead me to conclude that if mos- quitoes continue to exist in any locality it is because the people are too indifferent to the nuisance to take the trouble to be rid of it. THE IMPORTANCE OF INTERESTING CHILDREN. Under the general head of ‘‘Remedies’”’ we have mentioned the efforts made by Professor Hodge, in Worcester, Mass., to interest the school children of the city in the search for mosquito breeding places. This must have been in 1901-2. But the most serious and pro- ductive effort seems to have been made at San Antonio, Tex., a year or so later, at the initiative of Dr. J. S. Lankford, of that city. In November, 1903, there were cases of yellow fever in San Anto- nio which caused several deaths, and an inexcusable interruption of commerce that cost hundreds of thousands of dollars. In the effort to allay the panic, the existence of yellow fever was denied, not only _by persons having business interests in the city, but by many medical men as well. Very many adults not only denied the existence of the fever in the city, but denied the relation between the mosquitoes and the fever. Perhaps the majority of the adults seemed too old to learn; and to the enlightened physicians it appeared that it was impossible to begin education at the wrong end of life. The chairman of the sanitary committee of the school board (Doctor Lankford) grasped the happy idea that if the children were properly educated, sanitary matters in the future would be much better attended to. He suggested to the board that it would be valuable to educate all of the school children of the city in prophy-. laxis and make sanitarians out of them all. The school board heart- ily approved of the proposition, and the campaign was at once begun to educate the children on the subject of Insects as Disease Carriers. The best recent medical literature on the subject was procured and furnished to the teachers, and a circular letter was sent to them out- lining a proposed course and offering a cash prize for the best model lesson on the subject. Teachers became deeply interested in the subject. A crude aquarium, with eggs and wrigglers, was kept in every schoolroom, where the pupils could watch them develop; and large magnifying glasses were furnished in order that they might study to better advantage. The children were encouraged to make ORGANIZATION FOR COMMUNITY WORK. 87 drawings on the blackboard of mosquitoes in all stages of develop- ment; lessons were given and compositions were written on the sub- ject. Competitive examinations were held, and groups of boys and girls were sent out with the teachers on searching expeditions to find the breeding places. Rivalry sprang up between the 10,000 public school children of the city in the matter of finding and report- ing to the health office the greatest number of breeding places found and breeding places destroyed. Record was kept on the blackboards in the schools for information as to the progress of the competition and great enthusiasm was stirred up. In addition to these measures, a course of stereopticon lectures was arranged, grouping the pupils - in audiences of about 1,000 from the high school down, and, in Doctor Lankford’s words— It was an inspiring sight to watch these audiences of a thousand children, thoughtful, still as death, and staring with wide-open eyes at the wonders revealed by a micro- scope. It seemed to me that in bringing this great question of preventive medicine before public school children we had hit upon a power for good that could scarcely be overestimated. The result of this work, it is pleasing to say, was a decided diminu- tion in the matter of mosquitoes in San Antonio. There was some opposition among the people, but the movement on the whole was very popular. One result of this work was that while there had pre- viously been from 50 to 60 deaths a year from malarial trouble, the mortality was reduced 75 per cent the first year after this work was begun, and in the second year it was entirely eliminated from the mortality records of San Antonio. In organizing community work against mosquitoes, the school children hereafter must be counted upon as a most important factor. Almost every child is a born naturalist, and interest in such things comes to them more readily than anything else outside of the neces- sities of life. They are quick-witted, wonderfully quick-sighted, and as finders of breeding places they can not be approached except by adults of the most especial training. One of the first steps that a community should take is, therefore, the encouragement of the inter- est of the children in the public schools. RECENT WORK IN GERMANY. The city of Leipzig quite recently has begun a crusade against malaria under the direction of the city council. The following ac- count of this work was sent in by United States Consul S. P. Warner, and is published in the Daily Consular and Trade Reports for April 20, 1909: | So many cases of malaria have recently occurred in those sections of Leipzig which are adjacent to any one of the four rivulets which flow through the city that the city council has decided to adopt stringent measures to exterminate the mosquitoes (Anopheles) that spread the disease. 88 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. In order that the work of extermination may be thoroughly and systematically car- ried out, the city council has notified all housekeepers in the infected sections of the city to carefully examine their houses or apartments for mosquitoes and to destroy any that may be found. Every household in the districts concerned has been furnished by the city council with a large circular, which, in addition to information as to the cause and spreading of malaria, contains advice as to the best means of sabia the malaria mosquitoes. Certain dates have been specified between which the houses are to be searched and the mosquitoes destroyed. At the expiration of the time specified inspectors ap- pointed by the city council will visit each house and apartment and make careful examinations to see that the work of exterminating the mosquitoes has been properly carried out. Those who fail to comply with the 1egulations promptly and thoroughly will be subject to a fine of about $7.50. WORK ALONG RIVER FRONTS IN EGYPT. Communities living along river fronts may have good antimos- quito work hampered by the constant reintroduction of a mosquito supply from boats landing at their river fronts. This point has been especially noted in the course of the excellent work done at Khartoum. The following passage is taken from the first report of the Wellcome Laboratories, pages 21-22: At an early period the steamers were found to be largely infected, especially with . the larve of Stegomyia fasciata, and to a less extent by those of Culex fatigans. Ano- phelines, either as larve or imagines, have never been met with; but up-country, as will be noted later, the adults are frequently to be seen on board, and may remain as passengers for a considerable period. At first it was decided to use lime for the steamer bilges, but this was said, erroneously I believe, to act upon iron and to be unsuitable. ' Consequently crude petroleum was recommended, though not so good nor so easily applied. Along with this the periodical emptying of the bilge and fumigation with the sulphur squibs described by Colonel Giles were advised, the latter to get rid of the adult insects. Unfortunately in the case of the steamers, familiarity had evidently bred contempt, for, at first, despite the cooperation of the director of the steamers and boats department, little energy was displayed by the engineers in charge and the preventive measures were largely ignored, and in some instances even ridiculed. This was the more to be regretted, as there is no doubt that mosquitoes can be banished from all the steamers if a little care and trouble were taken. Mr. Beadnell, of the Geological Survey, carried out these simple methods on the S. S. ‘‘Nubia,’’ and practically cleared her of mosquitoes, so that for the first time he was able to sleep below in com- fort. A great improvement also resulted in the case of the gunboat ‘‘Zafir,”’ in which I went to Dueim and found to be simply swarming with adult Culices and their larve, while these measures absolutely prevented any mosquitoes breeding out on board the S. S. ‘‘Amka” during a period of nearly two months, the greater part of which was passed in regions swarming with these winged pests. Latterly, I am glad to say, the engineers have been impressed with the necessity of doing all in their power to aid the brigade. This is the more necessary, as it is easy for the steamers to infect the town and thus spoil much of the work done and render it futile. I am certain that this has . occurred in many instances * * *., AR pds Se - EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 89 EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES IN DIF- FERENT PARTS OF THE WORLD AND OF THE SANITARY RE- SULTS FOLLOWING THEM. It is proposed in this section to describe briefly some of the most striking examples of successful warfare against mosquitoes that have been carried out since 1900 and to bring them together into one consecutive account, a task that has heretofore not been attempted. Of many of them the details are not well known on account: of the inaccessibility of the documents of record. FEDERATED MALAY STATES. The work was begun at Klang and Port Swettenham in 1901 and 1902, the object being to abolish malaria, which was disastrous in its prevalence and virulence, by the extermination of mosquitoes by means of extensive drainage and the abolishing of breeding places. The town of Klang is situated on swampy ground lying between the Klang River—from which it takes its name—and a semicircle of low hills. Klang was formerly the terminus of the government railway and the port of the State. The river navigation, however, was diffi- cult, and a new port was selected near the mouth of the river, which was opened in September, 1901, and named Port Swettenham. The anchorage was good, but a half mile of mangrove swamp inter- vened between the shore and a wide extent of flat peaty land. The mangrove Swamp was intersected by a narrow road running up from the coast to Klang, some 5 miles away. After Port Swettenham was opened malaria increased alarmingly ; ‘almost all of the laborers were attacked, and many severe cases oc- curred on board ships lying alongside the wharves. A commission. was formed consisting of physicians and engineers, and antimosquito work of an extremely effective and complete character was carried out. The followig condensed account of the operations, and the tables showing striking results in the reduction of malaria, are taken from an article by EK. A. O. Travers, state surgeon, Selangor, and Malcolm Watson, district surgeon, Klang, published in the Journal of Tropical Medicine for July 2, 1906: Port Swettenham.—An area of about 110 acres, formerly low-lying swampy land covered with mangrove trees, has been cleared and carefully drained. In the neigh- borhood of the railway, government buildings, and town site a considerable area has been filled in and leveled, partly to do away with the breeding grounds of mosquitoes and partly to provide building sites. The whole area not occupied by buildings or roads is now covered by grass. The total expenditure on works other than the preparation of building sites has been (to the end of 1905) £7,000 [$34,020], and the annual cost of upkeep of drains, etc., is approximately £40 [$194.40] for clearing earth drains, and for town gardeners, £100 [$486]. 90 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Klang.—The area affected by the operations is about 332 acres. Twenty-five acres of virgin jungle and 80 acres of dense secondary growth (in places 30 to 40 feet high) have been cleared and 36 acres of permanent swamp have been drained. The areas cleared are now mainly under grass. The total expenditure to end of 1905 has been £3,100 [$15,066], and the cost of annual upkeep is about £60 [$291.60] for clearing earth drains, and £210 [$1,020.60] for town gardeners. As will be seen from the following statistics of cases of malaria treated Ae district hospital, Klang, the improvement in the health of the inhabitants of the areas treated began immediately after the completion of the drainage and other works and has continued to date. Table showing the number of cases of malaria admitted to the Klang hospital from Klang town and Port Swettenham, as compared to the number of cases admitted from other parts of the district. Residence. 1901. | 1902. | 1903. | 1904. | 1905. Wabi ey | Sethe Ade ya daeeis aua OO PL eee oe 334] 129 48 28 12 Klang and Port Swettiemham:4.: 2: 2.22.) 0.02 22s hce See tee 88 |. 20s. 23] beck ee a Port Swettebibam= _si5!. (5. 2/325382 doen; ESTES ss Pe 188 70 21 4 ll Oitiar parts of tasimeg 35 Woo be oi Soi pa sste, -AOSs, te eee 197 204 150 266 353 42] 1 | SRS 2 pane Serpent Vee ne eae Nee Aegean WE SOT als cee wee 219 298 376 a Certain persons lived some nights in Klang and some in Port Swettenham. The following table shows the number of deaths from fever and other diseases which have occurred at Klang and Port Swettenham during the last six years. The population in 1901 was about 4,000, but has largely increased since. Deaths in Klang and Port Swettenham corrected for deaths in hospital. Year. 1900. | 1901. | 1902. | 1903. | 1904. | 1905. Mewes Ly el yO ee AE ee ee hee. Pare eee FS 25 368 59 46 48 45 Other diseases 52.2 Be ee ie ee ee er 21 214 85 69 74 68 pial re Soh. Sy, ee eee ee oe 474 582 144 115 122 113 It will be noted that the remarkable improvement in the health of the inhabitants which occurred in 1902, immediately after the antimalarial works had been completed, has been well maintained. The following table shows the number of deaths occurring in the district of Klang, excluding the town of Klang and Port Swettenham. (Population 14,000 in 1901, since largely increased.) Deaths in Klang district, excluding Klang town and Port Swettenham. Year. | 1900. 1901. 1902. 1903. 1904. 1905. = > PASE Ae Ses pS er att ines Se ae eR EN ee oe | 173 266 227 230 286 351 AFERET GISERSCS oeC hs eae is hie eee heen | 133 150 176 198 204 271 TOGaL See ame een) oc. | A ee 306 416 403 428 490 622 These figures are especially valuable as a proof that the marked improvement in the health of the inhabitants of the towns of Klang and Port Swettenham is due to the antimalarial measures carried out, and not to a general improvement in the health of the district. 4 a f EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 91 In Klang and Port Swettenham we have 368 deaths due to fever in 1901, and 45 only in 1905; whereas in the rest of the district, which has not been dealt with by any special antimalarial works, we have 266 deaths due to fever in 1901 and 351 in 1905. It may here be mentioned that Klang is a large planting district about 380 square miles in extent, that it is mainly low-lying flat land, utilized for the cultivation of rubber, and that it would be almost impossible to protect the scattered population from malaria by drainage and filling in swamps. A great deal is now being done on most of the estates by regular administration of quinine, and also by protection from mosquitoes. Malaria in children as evidenced “ examination of blood.—No better indication of the presence or absence of malaria in any given district can be obtained than by a ase examination of the blood of children. The following details of the results of examinations carried out by Dr. Watson in 1904 and 1905 are of considerable interest: Results of examination of blood of children in Klang and Port Swettenham (specially drained areas). November and December, 1904. November and December, 1905. Number Percentage| Number Percentage examined. | 1fected- | infected. | examined. | fected. |“ intected. UENO 2 A ee a 173 1 0. 57 119 1 0. 84 Pore wettentiam:) 2 22 ...... 87 1 1:14 76 1 . 00 e772 |S a ae a re 260 2 76 195 2 51 Results of blood examinations in other parts of district not especially drained. November and December, 1904. November and December, 1905. Number Percentage | Number Percentage examined. Infected infected. | examined. Infected infected. 298 101 33. 89 247 59 23. 8 Improvement in health of government employees.—The remarkable way in which the health of the government employees residing at Klang and Port Swettenham has been affected is well shown by the following figures. It may be mentioned that in 1901 the number of persons residing at Port Swettenham, employed by the Government, was 176, and in 1904, 281. Table showing number of sick certificates and number of days’ leave granted on account of malaria. 1901. 1902. 1903. 1904. 1905. RA PENATOS Esc eo kere os ee ts BI Ao es gt ca UN a el 236 40 23 14 4 US Gia ae RP Oe oe ea ee ee cs ee eee 1, 026 198 73 71 30 The conclusions to be arrived at from the figures given in this report are very evident: (1) Measures taken systematically to destroy the breeding places of mosquitoes in the towns, the inhabitants of which suffered terribly from malaria, were followed almost immediately by a general improvement in health and decrease in death rate. eS v4, 92 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. (2) That this was due directly to the works carried out, and not to a general dying out of malaria in the district, is clearly shown by figures pointing out that while malaria has practically ceased to exist in the areas treated, it has actually increased to a considerable extent in other parts of the district where antimalarial measures have not been undertaken. The fact that the statistics for 1905 are even more favorable than those for 1902 is very strong evidence in favor of the permanent nature of the improvement carried out. If, as it is hoped, malaria has been permanently stamped out from Klang and Port Swettenham by works undertaken in 1901, our experience in the Malay States should be of value to those responsible for the health of communities similarly situated in many other parts of the world. THE WORK IN HABANA DURING THE AMERICAN OCCUPATION, 1901-2. One of the most striking examples of clean, efficient antimosquito work is that done by the American troops in Habana at the close of the Spanish war, under the direction of the Army Medical Corps and under the especial direction of Col. W. C. Gorgas, U. S. Army. In the statements which follow, Colonel Gorgas’s published writings have been freely used. Yellow fever had been endemic in Habana for more than 150 years, and Habana was the source of infection for the rest of Cuba. Other towns in Cuba could have rid themselves of the disease if they had not been constantly reinfected from Habana. By ordinary sanitary measures of cleanliness, improved drainage, and similar means, the death rate of the city was improved from 1898 to 1902 from 100 per thousand to 22 per thousand, but these measures had no effect upon yellow fever, this disease increasing as the nonimmune population increased, and in 1900 in fact there was a severe epidemic. Aédes calopus was established as the carrier of the fever early in 1901, and then antimosquito measures were immediately begun. Against adult mosquitos no general measures were attempted, although screening and fumigation were carried out im quarters occupied by yellow fever patients or that had been occupied by yellow fever patients. It was found that calopus bred principally in the © rain-water collections in the city itself; that Culex quinquefasciatus bred everywhere, and that Anopheles argyritarsis bred principally in the suburbs in pools and puddles well protected with grass. Two mosquito brigades were started—one to take care of ae and the other Anopheles. The work of the so-called ‘‘Stegomyia brigade” was confined to the built-up portions of the city. The city was divided into about thirty districts, and to each district an inspector and two laborers were assigned, each district containing about a thousand houses. The mayor of Habana issued an order requiring all collections of water to be so covered that mosquitoes could not have access, a fine being imposed in cases where the order was not obeyed. The water supplied Habana was very hard, and it was customary for every EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 93 family to collect rain water in barrels. As the majority of the people in the large tenement houses were poor, and as each family had a rain barrel, the health department covered these barrels at public expense, leaving a small screen opening through which the water could run and placing a spigot at the bottom through which it could be drawn. Every house in Habana, on the average, has a cesspool, the liquid contents generally seeping into the soil. The inspector on each visit had from 4 to 6 ounces of petroleum poured into the cesspool, and where this was not accessible it was poured into all closets connected with the cesspool; all receptacles containing fresh water that did not comply with the law were emptied, and, on a second offense, destroyed. If the owner was an old offender, he was prosecuted under the law and fined. -As a result of this work of the so-called “‘Stegomyia brigade,”’ whereas in January, 1901, there were 26,000 fresh-water receptacles containing mosquito larve, in January, 1902, there were less than 400 such receptacles containing larve; mosquitoes had rapidly decreased, and were entirely absent in many parts of the city. The result of this work, thoroughly done, was to wipe out yellow fever in Habana, and there has not been a certain endemic case since. The ‘‘ Anopheles brigade”’ was organized for work along the small streams, irrigated gardens, and similar places in the suburbs, and numbered from 50 to 300 men. No extensive drainage, such as would require engineering skill, was attempted, and the natural streams and gutters were simply cleared of obstructions and grass, while superficial ditches were made through the irrigated meadows. Among the suburban truck gardens Anopheles bred everywhere in the little puddles of water, cow tracks, horse tracks, and similar depressions in grassy ground. Little or no oil was used by the Anopheles brigade, since it was found in practice a simple matter to drain these places. At the end of the year it was very difficult to find water containing mosquito larve anywhere in the suburbs, and the effect upon the malarial statistics was striking. In 1900, the year before the beginning of the mosquito work, there were 325 deaths from malaria; in 1901, the first year of mosquito work, 151 deaths; in 1902, the second year of mosquito work, 77 deaths. Since 1902 there has been a gradual, though slower decrease, as follows: 1903, 51; 1904, 44; 1905, 32; 1906, 26; 1907, 23. WORK AT THE ISTHMUS OF PANAMA. The United States Government has very properly used the services of Colonel Gorgas, who was in charge of the eminently successful work at Habana, by appointing him chief sanitary officer of the Canal Zone during the digging of the canal. In 1904 active work was begun, and Colonel Gorgas was fortunate in having the services 94 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. of Mr. Le Prince, who had been chief of his ‘“‘mosquito brigades” in Habana, and therefore was perfectly familiar with antimosquito methods. In Panama, as in Habana, the population had depended principally upon rain water for domestic purposes, so that every house had cisterns, water barrels, and such receptacles for catching and storing rain water. The city was divided up into small dis- tricts with an inspector in charge of each district. This inspector was required to cover his territory at least twice a week and to make a report upon each building with regard to its condition as to breeding places of mosquitoes. All the cisterns, water barrels, and other water receptacles in Panama were covered as in Habana, and in the water barrels spigots were inserted so that the covers would not have to be taken off. Upon first inspection, in March, 4,000 breeding places were reported. At the end of October less than 400 containing larve were recorded. This gives one a fair idea of the consequent rapid decrease in the number of mosquitoes in the city. These operations were directed primarily against the yellow- fever mosquito, and incidentally against the other common species that inhabit rain-water barrels. Against ‘the Anopheles in the suburbs the same kind of work was done which was done in Habana, with exceptionally good results. The same operations were carried on in the villages between Panama and Colon. There are some twenty of these villages, run- ning from 500 to 3,000 inhabitants each. Not a single instance of failure has occurred in the disinfection of these small towns, and the result of the whole work has been the apparent elimination of yellow fever and the very great reduction of malarial fever. The remarkable character of these results can only be judged accu- rately by comparative methods. It is well known that during the French occupation there was an enormous mortality among the European employees, and this was a vital factor in the failure of the work. Exact losses can not be estimated, since the work was done under 17 different contractors. These contractors were charged $1 a day for every sick man to be taken care of in the hospital of the company. Therefore it often happened that when a man became sick his employer discharged him, so that he would not have to bear the expense of hospital charges. There was no police patrol of the territory, and many of these men died along the line. Colonel Gorgas has stated that the English consul, who was at the Isthmus during the period of the French construction, is in- clined to think that more deaths of employees occurred out of the hospital than in it. A great many were found to have died along the roadside while endeavoring to find their way to the city of Panama. The old superintendent of the French hospital states that one day 3 of the medical staff died from yellow, fever, and EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 95 in the same month 9 of the medical staff. Thirty-six Roman Catholic sisters were brought over as female nurses, and 24 died of yellow fever. On one vessel 18 young French engineers came over, and in a month after their arrival all but one died. Now that the mosquito relation is well understood, it was found during the first two years under Doctor Gorgas that although there were constantly one or more yellow-fever cases in the hospital, and although the nurses and doctors were all nonimmune, not a single case of yellow fever was contracted in that way. The nurses never seemed to consider that they were running any risk in attending yellow-fever cases night and day in screened wards, and the wives and families of officers connected with the hospital lived about the grounds, knowing that yellow fever was constantly being brought into the grounds and treated in near-by buildings. Americans, sick from any cause, had no fear of being treated in the bed immediately adjoining that of a yellow-fever patient. Colonel Gorgas and. Doctor Carter lived in the old ward used by the French for their officers, and Colonel ‘Gorgas thinks it safe to say that more men had died from yellow fever in that building than in any other building of the same capacity at present standing. He and Doctor Carter had their wives and children with them, which would formerly have been considered the height of recklessness; but they looked upon themselves, under the now recognized precautions, as safe almost as they would have been in Philadelphia. No figures of actual cost of the antimosquito work either in Habana or in the Panama Canal Zone are accessible to the writer, but it is safe to say that it was not exorbitant and that it was not beyond the means of any well-to-do community in tropical regions. WORK IN RIO DE JANEIRO. One of the most difficult problems of this character was that of freeing Rio de Janeiro from its reputation as the great yellow fever center. The difficulties were very great, and the amount of money required for efficient work was enormous. Rio de Janeiro has a population of more than 800,000 people; it extends over an area of 430 square miles; it is very irregular in its topography, varying in altitude from 1 to 460 meters (3 feet to 1,509 feet) above the sea level; it has 82,396 houses, and, as in all great centers of population, the inhabitants of very many of the houses, if not resisting the efforts of the sanitary authorities, surely did not facilitate them. The effort was begun in April, 1903, under the direction of the public- health service, but the organization effected was of a temporary character and needed the passage of new laws by congress, which was effected in January, 1904, and resulted in the reorganization . 96 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. of the hygienic service of Brazil and created a service for the stamp- ing out of yellow fever. One million six hundred and fifty thousand dollars was appropriated annually for this work. The service estab- lished included 1 medical inspector, 10 sanitary inspectors (physi- cians), 1 administrator, 1 customs inspector, 1 accountant, 70 medical students, 9 subchiefs, 200 overseers, 18 guards of the first class, 18 guards of the second class, and 1,000 workmen; and in addition to this personnel, the assistance of the public-health service corps of inspectors was called upon. The city was divided into zones, ac- cording to the density of the population, and the work was divided into two sections: (1) Isolation and sanitation; (2) the policing of the infected districts. Under the first section, yellow-fever patients were removed to the pesthouse, residents were isolated, and houses were disinfected. Under the second, the. sanitary poling force visited every building in the city, destrdaied the early stages of mos- quitoes, and screened .standing water where possible. One force worked in buildings, and another in vacant lots, streams, marshy lands, etc. The following paragraphs relative to this work are’ quoted from an address made before the Latin-American Medical and Sanitary Congress, held in Rio de Janeiro August 1 to 10, 1909, by Dr. Oswaldo Cruz: Yellow-fever cases were made known to the sanitary inspectors by the reports of medical assistants, of the head of the family in which a case occurred, or by any one to whom the facts of the case were known, in accordance with the requirements ‘of the law. The sanitary service being advised, a competent group of inspectors and authorities were at once dispatched to the locality, having with them a physician. The latter ascertained if the case was one for isolation treatment (whether under or over four days after the onset of the disease), and if the case required isolation the same was carried out either in the dwelling house or in the hospital, hospital treatment being resorted to only when the dwelling was unsuited to isolation treatment or when the patient wished it. In such cases the patient was taken to hospital in a vehicle closed against the entrance of mosquitoes, and the house was disinfected in accordance with the system below outlined. In the case of isolation in the home the physician chose a roomy quarter of the house with door opening into another secluded part of the house and with windows. If there were more than one door, the others were temporarily closed. The patient was kept under a netting enveloping the bed upon which he lay during the time permanent quarters were being arranged. The doors and windows of the room to be isolated and of the rest of the house as well were sealed to prevent the exit of mosquitoes existing there, the windows of the isolated room being fitted with wire screens in such a way as not to interfere with ventilation, all other openings to the outside or to other parts of the house being sealed with cloth or paper. The only door to be used in the use of the room must be specially fitted with a double door drum, provided with an arrangement which does not permit of both doors being opened at the same time. This apparatus prevents the entrance and exit of mosquitoes, and after the room is thus prepared the door and windows are closed and camomile is burned in the room 3 to 4 hours in the pro- portion of 10 grams per cubic meter of space. The room is then well ventilated and is ready to receive the patient. The rest of the house is well calked and isolated from the room in which the patient is placed, and disinfected with sulphur gas, as below indicated. During this operation a sanitary inspector remains in the room ee ae : EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 97 with the patient and stops the entrance of any gas which may possibly find its way through some overlooked crevice. During the preparation for disinfection the sani- tary authorities make a thorough inspection and destroy any mosquito larva they find, pick up or destroy any vessels lying about which might serve as a receptacle for mosquito-breeding water, and close water boxes against the same danger. The patient remains in isolation for seven days, after which isolation may terminate, if the family so wishes. The infected district is then treated as above indicated; that is, by disinfection, sanitary policing, and medical supervision. Disinfection is carried on in two ways, one force working from the center toward the outer limits of the district and the other from the boundaries of the district inward. The area of infection being determined over as large an area as possible, these two sections sepa- rate, one of which begins immediately with the house in which the case of yellow fever occurred, the other beginning at those houses which might possibly have. been infected at the greatest possible distance from the case in isolation. The purpose of such a system was to destroy all mosquitoes which might have carried infection within the district. While the disinfecting force is thus at work the police division, under the direction of a physician and of students who direct the different sections, operates throughout the infected district, making every effort to destroy all mosquito larvee and to prevent the possible breeding of mosquitoes outside as well as inside the house. Where larve are likely to exist in stagnant water or refuse of any sort, petroleum mixed with creoline, lysol, or similar products is thrown over the water or refuse in sufficient quantity to kill the larve instantly. Where it is impossible to use petroleum, as in the case of tanks and boxes for household use, a small fish, the ‘“‘barrigudo” or Girardinus caudi- maculatus, is placed in large numbers in the water. This fish destroys the larve of mosquitoes most voraciously. Larve in the drains are destroyed by the use of ‘‘Clay- ton gas,’’ which is pumped into the sewer, which has been previously divided into com- partments. Simultaneously with the disinfection the sanitary inspectors make daily inspection of the suspected district, examining every inhabitant supposed not to be immune—that is, children under 5, and all foreigners of less than 5 years’ residence in Rio. These are subjected to the closest vigilance, being placed in isolation at the least tendency to rising temperature. Reports are made in writing, those to whom this duty falls being required to fill out daily a bulletin sent out by the medical inspector to the chief of each district. In this report must be given the record of any who work outside the district or who for any reason absent themselves therefrom, a record of their condition being also kept by the physician in the district in which they work or are temporarily resident. When any inhabitant absents himself from the district the record must show his address, where he will be subjected to vigilance on the part of the authorities there. If the person under vigilance evades the attention of the physi- cian and withdraws without giving notice, the owner of the house in which he lived is fined, he himself is apprehended by the sanitary police, fined, and subjected to renewed vigilance. The vigilance in each district extends over a period of one month after the appear- ance of the last case. To give an idea of this service we will note the figures covering the prophylactic campaign in the infected district about the cotton factory, ‘‘ Fabrica das Chitas,’’ in 1906. The inspection was carried out by 18 doctors, who examined daily all suspected persons—in all, 7,966 persons, of whom 2,989 were not immune. Sixty cases were reported, of which only 19 proved to be yellow fever, and the district was declared entirely freed of infection after six months. With the combination of the three systems there is no doubt about cleaning up effectively any district in which yel- low fever may appear. In normal conditions the police service is carried out with equal painstaking, especially in the districts where infection last appeared. When, after some time, there seems no longer to be danger of new infection, the inspectors allow water to stand in several marked spots most favorable to mosquito breeding. © 37713—Bull. 88—10——7 98 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. These pools are then carefully watched, and examined at frequent intervals. This is a sure way to indicate the presence of the mosquito, and is a trap for those about to spawn. They are thus most easily destroyed. In many zones of the city these traps revealed the presence of no mosquitoes whatever. The actual results which followed this admirable work are shown by a table indicating the death rate from yellow fever in Rio from 1872 to date, which indicates that perfect success has been reached. Mortality from yellow fever in Rio de Janeiro from 1872 to. August, 1909. Year. Deaths. Year. Deaths. cy VA Sa eared Me gta Fae os Ec 2 Oe 102°|| 189k. bec ee ee 4,456 ASTSe Ses ad el easecsene. eee sealers 3,,659)|| 1892... 3.5. 2 eee 4,312 TRTA a SOON ee SO Ee ee ER 829° || 1893.02 ee af ee eee 8 ART Bie 2 os Roc oe ee ae ec rata Seemed 1,292 || 1894200 2.00 40.2 a eee 4,852 i eh ee ARR MMP REI SP RR 2c Pagan See 3.476) || 1805.0 2 ot clan ee 818 1: (7 ASA Soe Ee eR aN aN Cee iui ay nae ee eT eos OE S21 1896s. coe eR ae eee 2,929 7 (FE ga i ates Se ay Ranta ype xt es aE, A 1176. || W897 oo asos. ce eee eee eee EE eee eee ee 159 1 27) ee Bea Se A he a Maa Steg rd O74 Il W898 ol ss Pe eee ee eee 1,078 PSROS Syke nies now Bik ee ae dee ae Sans 1.625) Hl 2899. 235, Sees ee ae a Oe ee ee 731 ASRU ee re Hoc SRE S ak, 3s alt are cpeciete cra eee Me Saas 250 lt SQOOS Soe SO oe a ey 344 USSD aie ae aS. eee ee, SAR SETS SO) ESOU eee a Be eee ee 2,299 PRS Says AS sce Rot gi te We a tt See tone Soe 15608.) 1902 2 seo ck ee eo ee 9 RAD oe Et EROS ie aS ers Seca ao hare ee ee 863 || 1908).2 7.8222 ee 584 WSR ie dts teh Lege Sd cee eee ee BAB NW O04. 25 wep for ee wo lk rr S86 See ce ene boehe e oe 2 non Sie ee ee enero T4494 WOU a bos he ete he's ce cei eee 289 A cto (eR ae eS ee A Se eR eh Seat ieee Ee vee ee EST A906 oe ot be ie 3 Ee eee MC fo1 Fane Reta ore BO an RS eee eee pe CV AISs io (7a ie ee 39 1 SIC Nis’ Sie sem ALE Rb pies Wil Core ree n/a UMN 27456 |! GOSS. 2.380250 Lee ee 4 1 Teh a gies re A EE ie NR ON tae Spy age ae a Bie TAG) PAGO s2owds cereccucieete bs aoe eee 0 WORK IN ALGERIA. _ In 1902 an antimalarial campaign was begun in Algeria under the auspices and at the expense of the Pasteur Institute of Paris. The work was begun in a small way, and the service was afterwards ex- tended and supported by the Algerian government and is still being carried on. Dr. Edmond Sergent was assigned to the work, and in 1903 published an account of the early demonstrations. The inves- tigators propounded to themselves the following question: Is it pos- sible, under the practical conditions existing in Algeria, to defend a group of Europeans from malaria? And they decided to use no pro- phylactic measures whatever except the destruction of Anopheles. The management of the East Algerian Railroad placed at the disposal of the service one of the stations of that line. This station, which was called Alma, was a hotbed of malaria. Nine agents had been stationed there between the 1st of July, 1894, and the 1st of December, 1901. All of them were seriously ill with malaria, and the first eight left their positions on account of malarial fever on the advice of their physi- cians. The ninth was the man in charge at the time, who was very thoroughly infected. The families of these agents, concerning which there were no statistics, were all and always feverish, according to the best information. It seems that there did not exist a person who had ever lived in this station a single summer without contracting malaria. EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 99 At the time when the work began, June 26, 1902, there were 13 people living in the station; among them 9 had been there a year or more and were malarious; 4 had arrived during the winter and had never had any fever. In the neighborhood of the station there were two families, one of Arabs and one of French. All members of these two families were malarious and refused to be protected, and therefore constituted a constant source of infection for the Anopheles. It was the same way with the travelers who came to the station to wait for trains leaving in the evening or at night. Most of them were Arabs coming from near-by places notoriously unhealthy. The conditions of the problem were then severe. It was necessary to protect from the bite of infected Anopheles 4 persons not previously exposed and 9 others already malarious, the latter from reinfection. The measures undertaken were to protect this group of people from adult Anopheles and to destroy the Anopheles larve. This was done in the usual way. The openings to the buildings were screened—doors, win- dows, andchimney. All breeding places were searched for and found and were treated with kerosene. On leaving the station at night veils and gloves were used; but in spite of this watchfulness it was not cer- tain that all of the house people invariably observed this precaution. The results were excellent. The numbers of the mosquitoes were greatly reduced by the work against the early stages; the building was almost entirely protected, so much so that but 9 Anopheles suc- ceeded in gaining entrance. At the end of the season not one of the 4 new people had shown the slightest symptoms of malaria, a con- dition which it is safe to say had not occurred before in that locality, and the others, although having some fever, showed no indication of reinfection. This was only an initial experiment to prove what could be done, and the results were placed before the governor-general of Algeria and the members of congress as well as the departmental and communal authorities. The expenses incurred amounted to $58.83. The gov- ernmental efforts since that time seem to have been very consider- able. In 1904 malaria was pandemic in Algeria, but by increased knowledge and increased efforts the report for 1908 shows that in that year the situation was very much better and not to be compared with that of 1904. The effort takes the form of conducting demonstra- tions in order to give lessons to the people and to widen each year the territory covered, and to organize antimalarial campaigns in different malarial localities by the physicians, the engineers, etc., stationed in those localities. Propagandic work of all kinds is going on, including placards in the railway carriages and elsewhere and teaching antimalarial measures in all the schools. The last report published—that giving an account of the operations for 1908—indi- cates an awakening of the country that can not fail to be productive of great good. 100 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. WORK IN ISMAILIA. Another striking example of excellent work of this kind is found in the report, published in 1906, on the suppression of malaria in Ismailia, issued under the auspices of the Compagnie Universelle du Canal Maritime de Suez. Ismailia is now a town of 8,000 inhabitants. It was founded by De Lesseps in April, 1862, on the borders of Lake. Timsah, which the Suez Canal crosses at mid-distance between the Red Sea and the Mediterranean. Malarial fever made its appearance in very severe form in September, 1877, although the city had up to ‘that time been very healthy, and increased so that since 1886 almost all of the inhabitants have suffered from the fever. In 1901 an attempt to control the disease was made on the mosquito basis, and this attempt rapidly and completely succeeded, and after two years of work all traces of malaria disappeared from the city. The work was directed not only against Anopheles mosquitoes, but against other culicids, and comprised the drainage of a large swamp and the other usual measures. The initial expense amounted to $9,650 and the annual expenses since have amounted to about $3,531.90. The results may be summarized about as follows: Since the begin- ning of 1903 the ordinary mosquitoes have disappeared from Ismailia. Since the autumn of 1903 not a single larva of Anopheles has been found in the protected zone, which extends to the west for a distance of 3,281 feet from the first houses in the Arabian quarter and to the _ east for a distance of 5,906 feet from the first houses in the European quarter. After 1902 malarial fever obviously began to decrease, and since 1903 not a single new case of malaria has been found in Ismailia. WORK IN VERACRUZ. The president of the superior board of health of the Republic of Mexico, Dr. Eduardo Liceaga, was one of the first to grasp the im- portance of the mosquito discoveries of the American army board and one of the first to make an effort to put them into effect. As elsewhere, he met with conservatism and a certain amount of dis- belief, but it was not long before he succeeded in establishing an anti- mosquito service for practically all of the towns in which the disease appeared to be endemic, and devoted especial attention to the larger seaports most frequently entered by foreign vessels. In 1893 the disease spread in an epidemic form to several cities of the Gulf States of Mexico and to some interior cities as well, such as in the States of Nuevo Leon and San Luis Potosi. By the aid of strong executive orders on the part of President Diaz, the superior board of health was able to take action in all of the States except one, and was able to arrest the epidemic. The plan of campaign was based upon the mosquito doctrine, and the measures involved the isolation of patients, the rigorous disinfection of dwellings by sulphur dioxid, the drainage — — ee eee EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 101 of swamps, covering of drinking-water reservoirs, and the use of petroleum. In the course of this work and that which followed, with the under- standing that Veracruz is the oldest and most permanent focus of endemia of the Mexican Republic, and that all the epidemics had found their origin in that place, the principal attention of the superior board of health was devoted to that city. The town was divided into four districts, each of which was placed under the charge of an expe- rienced physician, and each of these had first-class sanitary agents. Subordinate to these, other second-class agents were appointed, and a certain number of laborers were added. As a result of this effective organization, Carroll, writing his chapter on yellow fever for Osler’s - Modern Medicine, at the close of 1906, was able to make the following statement: In Mexico yellow fever has been eradicated from its endemic focus at Veracruz through the able efforts of Eduardo Liceaga, the president of the superior board of health, whose complete grasp of the problem and whose enlightened and energetic action has added support to the mosquito doctrine, and would have controlled the disease absolutely if the same means of enforcement were available in Mexico as in Cuba in 1901. The later developments of the work in the Mexican Republic under Doctor Liceaga’s leadership have been remarkable. In the American Journal of Public Hygiene, new series, Volume VI, No. 1 (February, 1910), is published Doctor Liceaga’s Annual Report on Yellow Fever in the Mexican Republic, from August 16, 1908, to date, a paper read before the American Pubiic Health Association, at Richmond, Va., October, 1909. The following paragraphs concluding this report will give an idea of the excellent results which have followed the work of the sanitary officials in Mexico: The campaign against yellow fever, which commenced in the Mexican Republic in the year 1903, has continued uninterrupted up to this date, without even suspending it during the winter months as is done in other countries; that the war on the mos- quitoes is so efficacious that there are none left in Veracruz, and, consequently, there are no stegomyias, as demonstrated by the reports rendered by the physician of the Public Health and Marine-Hospital Service of the United States, who is resident in that port. The cases which have been observed in Merida and surrounding villages arise from the existence in that city of over thirty thousand water tanks which could not be so easily and securely watched as those of Veracruz. In the entire section which was formerly devastated by yellow fever we continue to canalize the deposits of standing water and to fill up the hollows, as well as to spread oii on all those ponds which cannot be otherwise filled in or covered. We continue to fumigate the dwelling houses, workshops, schools, etc., in which we have encountered either cases of yellow fever or any suspected cases. We continue the surveillance over the passengers who travel by rail in any part of - the region which formerly suffered from yellow fever, and this service is especially active along the line of the Tehuantepec Railroad. In the ports of Coatzacoalcos, on the Gulf coast, and Salina Cruz, on the Pacific, it is nearly four years since a single case of yellow fever was observed. r+ W af Be 102 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES, : WORK IN JAPAN. Work in Japan as early as 1901, under Surgeon Major Tsuzuki, con- firmed experimentally the malarial relations of Anopheles, and later a large-scale experiment was carried on among the Japanese troops occupying Formosa, which, on account of its extent, served to set at rest any doubts which had previously existed as to the value of mos- quito protection. Portions of Formosa are malarious, and the following table indicates the conditions existing among these troops from 1897 to 1900: Number of | Number of| Ratio of Ratio of patients. deaths. patients. deaths. —— eee Se Per cent. Per cent. oS / (ay einer L MUMRU DIE dpihe SUR RS Aaya ba ite creer a © aim ts 41, 825 267 272. 435 1.739 1 hts eT ae gery elas ser erariiar, adenine 4 Aart cree ear eS 34, 752 270 249. 394 1. 938 To eae eS ane gues engage NS go RA 8 Mea eg ng Bk 29,371 284 221. 263 2.139 POND) owl cents So Gal ook ee Sore eet eC Gee hace ees 30, 224 272 222. 414 2.002 On the 21st of September, 1901, and extending through to the 28th of February, 1902, work was carried on by order of the governor of Formosa, on the advice of Doctor Koike, surgeon-general, as follows. This account of the experiment is taken from an address by Dr. K. Tamura, delegate from Japan to the Eleventh Annual Meeting of the Military Surgeons of the United States Army, June 7, 1902: | ) Half of the second company, first battalion of infantry at Kirun, Formosa, 115 in number, was employed from the day of their landing at Kirun, and we gave it the name of “protected troops.’’ This troop. was thoroughly provided with means of protection from mosquito bites. They were confined in the casern from half an hour before sunset to half an hour after sunrise, the casern having been specially made to prevent mosquitoes entering, and they wore gloves and coverings of the head specially made for that purpose when on service at night. The results of these new methods for the prevention of malaria were absolutely good. Another half of the second company (called by us “comparison troop’’) and all the other companies of the battalion (called by us “unprotected troop’’) had a great many malaria patients, but the protected troop had none. The table of the number of patients is as follows: Average | Number of| Ratio of cay patients. | patients. Per cent. Protected troOpess ja: te oe o> onl oaks nays See ee ee ob eee eee 114. 49 0 COMParisonitLOOPs. ene eee a= ee sacs ss Ce ee Eee ee tere eee ee eee 104. 34 34 32. 59 Uuprotected troop. . ei o2ecdr x. 20... ns Ps ca Se ee 646. 36 285 44.09 The experiment of Grassi in Italy shows that 5 cases of malaria were observed among 112 persons, and Celli observed 11 cases in 203 persons, but our case shows none in 114 persons. a EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 103 The news was spread rapidly in the whole island and all the troops despatched there became very cautious regarding the bites of mosquitoes. This caution itself gave good results, and the number of patients and deaths decreased distinctly last year, compared with the preceding years: Number of | Number of| Ratio of Ratio of patients. deaths. patients. deaths. : Per cent. Per cent. yenmieay to 1900 javerage. 1... i620. eee cccs sabes eles 34, 043 27,325 242. 514 1. 947 Pe oo lao a a a aie mite eniwiS Glee Jes oi 22, 438 14, 500 173. 211 1.119 Now it is very clear that the prevention of malaria is secured by guarding against mosquitoes, and we believe that Formosa will become a healthy island within a few years. In the recent war between Russia and Japan, the Japanese gave the world an example of field sanitation hitherto unequaled in history, a vivid account of which will be found in ‘‘The Real Triumph of Japan,” by Dr. Louis Livingston Seaman, formerly surgeon-major, United States Volunteers (New York, 1907), from which the following facts are drawn: | Longmore’s tables, based on the records of the battles of the last two hundred years, show that there has rarely been a conflict of any long duration in which there have not been four deaths from disease to one from bullets. In the Spanish-American war there were' 14 deaths from disease to 1 from battle. Japan in her war with China in 1894 lost 3 from disease to 1 from bullets; but from February, 1904, to May, 1905, in her war with Russia 4 were lost in battle to 1 only from disease, the exact figures being 52,946 lost in battle and 11,992 lost from disease, and the significant fact must be added that of the total sick only 3.51 per cent were sick with infectious diseases. There were only 1,257 cases of malaria in the whole army, 600,000 strong, in the eighteen months duration of the war, whereas in 1894, in the war with China, there had been 41,734 cases of malaria. At the outset of the campaign the purifying of cities occupied was begun and attention was paid to mosquito breeding-places. One of the orders issued was that the waste water of the barracks should be connected with the town gutters. Incidentally it may be noted that all articles sold publicly were required to be covered to protect them from flies. In the book of health instructions issued to soldiers occurred the paragraph, ‘‘Malaria is spread by mosquitoes; therefore protect yourself from them as much as possible.’”’ The soldiers had their camp kettles with them, they were furnished with water boilers, and all water had to be boiled before being drunk. They were fur- nished with mosquito bars, and every man was enveloped in a bar during the mosquito season. The result of 1,257 cases of malaria out — of an army 600,000 strong must be contrasted with a telegram sent from General Shafter at Santiago on August 8 during the Spanish- 104 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. American war, which read ‘‘At least 75 per cent of the command has been down with malarial fever, from which they recover very slowly * * *.”” Tt should be noted that Major Seaman was disappointed not to find mosquito nettings in the main hospital in Tokio and that he states that this hospital was inferior in this and certain other respects to the second and third reserve hospitals in Manila. He states that at some of the hospitals netting was added as the mosquito season approched, but it is only fair to infer that at this main hospital the Japanese surgeons knew what they were about and were certain that the absence of the mosquito bars involved no danger to the ~ patients. ANTIMOSQUITO WORK IN OTHER PARTS OF THE WORLD. Nothing has been said in this bulletin about the admirable work which had been carried on in Italy. Taking a prominent part in the demonstration of the conveyance of malaria by Anopheles, the {talian investigators were practically the first to begin active anti- mosquito work. Their results were so striking that they received the attention of the entire civilized world, many accounts having been published in newspapers and magazines and in more permanent form. The whole world may, in fact, be said to be familiar with this work, which will be, however, more extensively mentioned in a bulletin on malaria and the malaria mosquitoes which it is hoped to publish later in the year. Active and well-organized antimalarial work is being carried on in many places in the Tropics, and an effort has been made to estab- lish an antimalarial league in Greece which has the support of wealthy people and of the nobility of several countries, but in practically none of the well-settled countries in temperate regions has any work of importance been done, even in regions whose development is dis- tinctly held in check by this disease. The government of India has never been able to carry out broad concerted measures of any great importance, although most important investigations have been car- ried on in that country. It was recently decided to convene a con- ference to examine the whole question and to draw up a plan of cam- paign for the consideration of the general government and of the local © governments. This conference assembled at Simla on October 11, 1909. Inthe resolution which brought about the call it is pointed out that the actual death rate from malarial fever in India is 5 per 1,000; that this represents about 1,130,000 deaths, and, as mortality in malarial fever is ordinarily low, a death rate of even 5 per 1,000 indi- cates an amount of sickness, much of it preventable, which clearly calls for the best efforts that government can make to diminish it. An editorial in the Journal of Tropical Medicine and Hygiene for EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 105 September 15, in speaking of this resolution and the proposed confer- ence, anticipated that nothing will come out of the movement. It says: To those, however, who have read many similar resolutions and have perhaps acted on committees of the sort, the solemn rigmarole, with its characteristic touch on the ‘‘prohibitive costs of attempts to exterminate the mosquito,’’ implies no more than _ an expedient to stave off the dreaded day when public opinion will force the govern- ment of India to act instead of to talk on this really and literally vital question. The report of the conference as given in Nature, November 5, 1909, indicates that many important addresses were made, including one _ by Colonel Leslie, the sanitary commissioner of the government of India, and others by such well-known workers as Major James and Captain Christophers, of the Indian medical service. Colonel Leslie advocated quinine prophylaxis. Major James introduced a discus- sion upon the distribution of malaria in India and advocated a gen- eral investigation in every province similar to that which Captain Christophers made in the Punjab. Quite in the line of prophecies of the editorial in the Journal of Tropical Medicine and Hygiene, Major White, of the Indian medical service, stated that he considered the recommendations of past malaria conferences are costly, and almost prohibitively so if undertaken annually, and contended that more should be done with the propagation of fish which prey upon mosquito larve. At the termination of the conference various conclusions and recommendations were drawn up under the following main headings: (1) Scientific investigation; (2) the agency by which investiga- tion should be made; (3) practical measures, including (a) extirpa- tion of mosquitoes, (b) quinine treatment and prophylaxis, (c) education, and (d) finance. In the United States, it is sad to relate, almost nothing has been done in the way of an active campaign against malaria alone, even in restricted localities. It is true that extensive work has been done against mosquitoes, but in the most of these cases the incentive does not seem to have been to better the health of the people or to stamp out malaria. We have shown that in the New Jersey work the item of personal comfort is concerned and that. of the enhanced value of real estate and the enhanced taxable value of land to the community, but the main fight there is conducted against mosquitoes that have no relation to disease, although Doctor Smith has written much against malarial mosquitoes and has conducted a strong educational cam- paign. We have shown also that the fight against mosquitoes in the marshlands back of Brooklyn was financed by a wealthy man whose immediative motive was to keep his race horses in better condition by preventing the annoyance to them of mosquitoes. In different - communities there have been intelligent and up-to-date citizens who have made strong efforts to start malarial campaigns, but we have 106 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. not reached success, through indifference on the part of city councils or other bodies controlling public funds. Many health officers them- selves have seemed indifferent on this subject. In some localities citi- . zens’ associations, civic improvement societies, and women’s clubs have made efforts to improve the situation. Good work was done - by such an orgainzation in South Orange, N. J., and instances of this kind are scattered here and there at very long intervals over the country, but these efforts as a rule were at first spasmodic and only temporary in their effects. The city of Baltimore offers an excellent example of what we have just stated. It was early shown that a very large part of the mosquito supply could easily be handled, and there were not lacking intelligent and enterprising citizens who, year after year in the public press and before the board of health and the city council, continually agitated the subject of antimosquito work. Finally in 1907 Mr. George Stewart Brown, a member of the city council, succeeded in getting an appropriation to start the work for that year. Much of this money was expended in expensive advertising in the street cars, etc., but the remainder was expended very efficiently, but necessarily with only partial results, by organizing a gang of men to drain and fill up pools in vacant lots around the suburbs. The next year the appropriation was reduced, and only the gang of men was continued. During 1909 no appropriation was made, the gang of men was dropped, and the whole question was abandoned. It should be stated, however, that before the appropriation was made an ordinance was passed by the city council requiring every householder to remove, screen with wire netting, or keep covered with oil, all standing water on his premises, but it seems that no real attempt was ever made to enforce this ordi- nance. Of course such an attempt could hardly be successful at first without the aid of a special appropriation for the purpose. At the present time the ordinance seems to be a dead letter. It is true that even where not directed specifically against malaria, but against the mosquito nuisance, the breeding places of Anopheles are disposed of, and they are for the most part prevented from breeding, together with the other species of mosquitoes, and for this reason a little space will be devoted to some of the productive efforts which have been made in the United States aside from those which have already been considered at some length in the section on drain- age and other neighboring sections. In the early days of antimosquito work in this country, 1901 and 1902, the rather rare citizens who appreciated the situation and who did their best to stir up their communities to organized effort should be mentioned, and among them we have specifically in mind Dr. Albert F. Woldert, of Philadelphia and later of Texas; Dr. Henry Skinner, of Philadelphia; Dr. H. A. Veazie and Dr. H. G. Beyer and EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 107 a little later Dr. Quitman Kohnke, of New Orleans; Mr. H. C. Weeks, of Bayside, Long Island; Mr. W. J. Matheson, of Lloyds Neck, Long Island; Major Barton, of Winchester, Va.; Dr. W. S. Thayer, of Baltimore; Mr. Wm. Lyman Underwood, of Boston; Dr. A. H. Doty, of New York; Mr. Spencer Miller, of South Orange, N. J.; Dr. W. F. Robinson, of Elizabeth, N. J.; and Dr. J. W. Dupree, of Baton Rouge, La. We have not mentioned any entomologists in this list, but surely Dr. John B. Smith, of New Jersey; Prof. Glenn W. Herrick, of Mississippi; Dr. E. P. Felt, of New York; Prof. H. A. Morgan, of Louisiana; Dr. W. E. Britton, of Connecticut; and Mr. D. L. Van Dine, of Hawaii, should be named, and of course since those early days nearly every economic entomologist has become an apostle. After 1902 the ranks became greatly increased, and at the present time conditions are being bettered, although still without the existence of any large well-organized campaign directed solely against malaria. _ One of the best pieces of work with a direct antimalarial bearing that has been carried on in this country, and that was begun at an early date, is that started on Staten Island under Doctor Doty, the health officer of the port of New York. The following account is largely taken, word for word, from a letter recently received from Doctor Doty, but it can not be directly quoted on account of occa- sional necessary alterations of the verbiage of a personal letter. Staten Island, lying in New York Harbor, had had a rather un- enviable reputation on account of the great number of mosquitoes present and the continued presence of malaria. It was largely on account of the latter condition that Doctor Doty began his investi- gation in 1901. He soon found that there were two factors to deal with in this work, namely, the inland mosquitoes and the salt-marsh mosquitoes. In the extermination of the inland mosquitoes, the section of Staten Island which was known to contain many cases of malaria both in the acute and chronic forms was selected for experimental work. This section consisted of a basin or lowland about a mile square, containing about 100 small dwelling houses some distance apart. Within its boundaries were a large number of stagnant pools varying in size from 10 feet in diameter to an acre or more in area. A house- to-house visit showed that at least 20 per cent of the inhabitants of this district were suffermg with some form of malaria, and in the immediate vicinity of every house were found typical breeding places _in the shape of old tinware, rain-water barrels, cisterns, cesspools, and ground depressions, many of which contained larve. For the purpose of detecting the presence of adult Anopheles, glass tubes fitted with cotton plugs were distributed among the occupants of these houses, with the request that the mosquitoes found in the 108 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. house at night be captured and placed in the tubes. In the collec- tion were found many Anopheles. These were particularly numerous in tubes coming from a small group of houses. In one of the latter was found a family consisting of five persons, all of whom showed the acute or chronic form of malaria. Doctor Doty himself secured live mosquitoes from the interior of this house. On the first evening 5 were captured, and all but one were Anopheles. On the second evening 22 were collected, and of these more than one-half were Anopheles. Ina house on the opposite corner was found a patient suffering from an acute attack. In the beginning considerable difficulty was found in detecting the breeding places of the Anopheles, but this became easier as the in- spections became more thorough. For instance, in a group of two or three houses close together, a number of Anopheles were captured, but their breeding place could not be found for some time. Finally, in the backyard of one of the houses, overgrown with weeds, was discovered a very large metal receptacle filled with Anopheles larve and with many adults in the immediate vicinity. This receptacle was almost entirely covered by underbrush. After this experience the men employed learned to make the closest possible search and to find probably every breeding place. The island was then divided into small districts, which were visited by a mosquito corps consisting of five men, one of whom was a sanitary police officer connected with the New York City depart- ment of health. The equipment of the mosquito corps consisted of a large wagon provided with spades, rakes, hoes, scythes, and petroleum oil. A house-to-house inspection was made in each district. House owners or tenants were required to remove from about the premises — all receptacles which might act as breeding places, or to protect them. Rain-water barrels and cisterns were covered with wire netting, all roof gutters were repaired, and pools of water were covered with petroleum. In certain instances orders were sent to the owners of property containing depressions in the soil to fill them or drain them. If these orders could not be enforced, the mosquito corps returned every ten days or two weeks and applied more petroleum. Copies of a circular of information were delivered so far as possible to each house on Staten Island by police officers, and this educational cam- paign brought about valuable cooperation on the part of the public. In 1905 the details of this work were presented to the department of health of the city of New York, and the city government granted an appropriation for the drainage of the swamp land along the entire coast of the island. With the aid of this appropriation, ditch- ing was carried on somewhat in the same manner in which it has been carried on in New Jersey. Down to the present time between 800 and 1,000 miles of ditches have been dug. The swarms of mos- EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 109 quitoes soon practically disappeared, window screens were discarded, and meals were served upon the verandas of the hotels. With the malarial and other inland mosquitoes the work was car- ried on in the manner above described, not only in the built-up portion of the island, but also in the open spaces between the small and scattered settlements. During the past two years cases of malaria on Staten Island have become practically unknown, and for the past year. Doctor Doty has been unable to secure any Anopheles, whereas in the beginning of the investigation they were found almost everywhere on the island. The statistics of the department of health indicate the decrease of malaria from 1905 on. Prior to 1905 malaria was not regularly reported, but the number of cases was surely very much greater than that reported in that year. Since 1905, however, they are stated to be as follows: 1905, 33 cases; 1906, 54 cases; 1907, 4 cases; 1908, 6 cases; 1909, 5 cases. The work of exterminating malarial mosquitoes has been neces- sarily slow, as the area involved is considerable, the island being about 16 miles long and from 4 to 6 miles wide, probably containing over 80,000 inhabitants, with large areas between the various towns. The expense of the operations down to the present date has been about $50,000; this of course includes the expense of the extensive drainage operations in the salt marshes. Doctor Doty, in addition to being the health officer of the port of New York, is a commissioner of health of New York City, and he carried out this work in his capacity as a municipal officer and not as a state official. There were some earlier and very much smaller pieces of work, which have previously been described by the writer. Dr. W. N. Berkeley, in the Medical Record of January 26, 1901, gave a most interesting account of a malarial outbreak in a small town near New York City during the summer of 1900. Around a large pond in the vicinity of the town four or five fresh cases had recently developed in August. The first case was that of a coach- man, who had caught malaria elsewhere and had relapsed. From his quarters in a long row of stables on one side of the pond the infection had passed along to other stablemen and servants on the same side, to the distance of a quarter of a mile from the original site, and a quarter of a mile in another direction across the pond one other case appeared in a small child. Doctor Berkeley went to the town and discovered that Anopheles quadrimaculatus was fairly abundant in every bedroom in that area in which proper search was made. The breeding places seemed to be segregated pools at the end of the pond (the pond itself contained fish) and post holes and excavations. These last were numerous, as many buildings were going up. The following practical measures were adopted: (1) Ex- termination of all the Anopheles found in houses by a party of men 110 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. sent out for the purpose, and this was followed by a systematic introduction of screens in windows and doors; (2) filling in of the smaller breeding places and the drainage of the pond; (3) the seclu- sion of every malarious patient by netting and otherwise from the bite of mosquitoes, so long as he had germs in his capillary blood. The results were as prompt as they were gratifying. Not a single new case of malaria developed; Anopheles disappeared entirely from houses where it had been previously a night terror, and Culex was greatly diminished in numbers. Another interesting case has been described by Rev. William Brayshaw, of Chaptico, Md. Chaptico is situated at the head of a widespreading bay or elbow of the Wicomico River, about 8 miles from the point where this river enters into the Potomac at Rock Point. The tide is ordinarily about 2 feet at the full. The village rests between two hills of 80 or 90 feet elevation. The valley is almost flat, and consists of marshy pools, in which the mud or ooze can easily be pierced with a strong pole to a depth of several feet. Three of these pools or ponds are directly in the rear of the house known as the rectory, in which he resided with: his wife on June 24, 1890. Neither of them had ever had malaria or fever before, but the mosquitoes were so numerous that it was impossible to take rest at night for a while. On July 11 his wife was taken with malaria, and on September 4 had to be removed to the mountains. Mr. Bray- shaw himself was sick most of the time, and every house in the vil- lage had from one to five persons suffering from malaria. He pro- posed ditching and drainage, but there was no money, and every- body laughed at the idea, as many of the citizens had lived there from childhood to an advanced age. There did not seem to be suf- ficient fall to carry off the “‘effete matter.”” On May 19, 1900, he gained the consent of the property owners to ditch through their land a distance of 560 feet to Chaptico Creek. -He paid for this himself. The expense was about $40. The result he sums up as ~ follows: During the summer of 1899, from May to October, the mosquitoes were so numerous that life was a burden during the night, and they were so small that nets seemed to have no effect upon them. From May to October, 1900, quite a number visited us, until June 12, when they disappeared, and we were free from them until the last six days in September, when I found a local cause for their breeding. In the summer of 1899 every house in the village had from one to five persons sick with chills and fever and other malarial troubles; doctors in constant attendance. In the summer of 1900 there were only two sporadic cases of chills, both caused by negligence or inat- © tention to ordinary caution. Everyone in the village seems quite free from malaria since July 10. Later some excellent work was instituted through the combined action of the boards of health of Cambridge and Belmont, Mass., to— improve the sanitary condition of the cities of Cambridge, Somer- EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. 111 ville, and the towns of Arlington and Belmont, at the inspiration of Mr. W. L. Underwood, a member of one of the boards of health. This was effectively carried out at an expense of $600 without assess- ment upon landholders. An account of this work by Mr. Under- wood is given in the Technology Quarterly of March, 1901. The work of the North Shore Improvement Association of Long Island has been mentioned rather fully in the sections on remedies. This work was thorough and resulted in the improved sanitation of that portion of Long Island. In 1903 some extensive work was done in Newport, R. I., at the expense of the property holders, under the direction of Mr. Henry Clay Weeks, with good results. The Citizens’ _ Association of Flushing, Long Island, later took up the problem, and with the assistance of the board of health extensive drainage operations have been carried on but are not yet completed. At Wellfleet, Mass., other work of a somewhat similar character, but directed for the most part against the salt-marsh mosquitoes, is now under way. A most interesting bit of work was carried on in the southern part of the Borough of Brooklyn in 1902-3, under the supervision of Mr. Weeks, which has been described in the chapter on remedies. This work, which was of an expensive character, was lately paid for by a private citizen, Mr. Whitney. An important step forward was taken in 1903 in the formation of the American Mosquito Extermination Society, in which W. J. Matheson, of New York, the president, and Henry Clay Weeks, also of New York, the secretary, were the leading movers. This society, in which nearly all persons actively interested in the mos- quito crusade became interested, was started for the purpose of edu- cating the public, bringing about legislation, and securing coopera- tion and interchange of ideas. It held its first antimosquito con- vention December 16, 1903, in the rooms of the Board of Trade and Transportation, Mail and Express Building, New York City. The convention was called to order by Mr. Henry Clay Weeks as acting chairman, who made some introductory remarks, after which officers were elected. The following papers were read: “How a State Appropriation May be Spent,’’ by John B. Smith. “What a Rural Community Can Do,’’ by Walter C. Kerr. “The World-Wide Crusade,’’ by L. O. Howard. “Does Extermination Exterminate Mosquitoes?’’ by W. J. Matheson. “Remarks on Extermination Work at Morristown, New Jersey,’’ by John Claflin. “The Extermination and Exclusion of Mosquitoes from Our Public Institutions,”’ by P. H. Bailhache, surgeon, U. S. Public Health and Marine-Hospital Service. “Government Antimosquito Work,’’ by Dr. J. C. Perry. “The Sphere of Health Departments,’’ by Dr. E. J. Lederle. “The Exactness of Proofs of Transmission of Malaria by Mosquitoes,’’ by Dr. W. N. Berkeley. “The Long-Distance Theory,’’ by Spencer Miller. bie a. v¢ i 112 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. nr a “The Value of Reclaimed Swamp Lands for Agricultural Uses,’’ by Milton Whitney. “Antimosquito Work in Havana,’’ by Col. W. C. Gorgas, U. S. A “How the Law Should Aid,’’ by Paul D. Cravath. “New York State’s Part in Mosquito Extermination,’”’ by E. P. Felt. “What the Government Should Do,”’ by F. C: Beech. “Mosquito Engineering,’’ by Henry Clay Weeks. “The Work of the Department of Health, New York City,” by Henry C. Weeks. Following this organization meeting, a somewhat elaborate organi- zation was perfected, including an advisory board and an advisory board of entomologists. The proceedings of the convention were pub- lished in pamphlet form and were distributed free of charge. A mos- quito brief was published as a folder giving mosquito information. In November, 1904, Bulletin No. 1 of the society was published, which contained in digested form an account of the work which had been going on in the meantime. Bulletin No. 2 contained a report of the president and secretary to the executive council, published September 26, 1905, and in 1906 was also published a yearbook for 1904-1905, which ‘contained the proceedings of the second annual convention of the organization. These proceedings contained a num- ber of valuable addresses, some of which may be mentioned: ‘‘Diversities among New York Mosquitoes,’ by E. P. Felt. ‘‘Mosquito Extermination in New Jersey,’’ by John B. Smith. ‘‘Extermination and Dissection of Mosquitoes,’? by M. J. Rosenau of the United States Public Health and Marine-Hospital Service. ‘“Mosquito Extermination in New York City,’’ by Thomas Darlington. “The Mosquito Question,’’ by Quitman Kohnke. ‘The Relation of Mosquito Extermination to Engineering,” by Cornelius C. Ver- meule. The society continued its work, and unquestionably well justified its organization. In 1907, however, it was deemed by the officers of the society that the objects of its existence could well be taken over by the National Drainage Association, which had then recently been formed and which placed among its most prominent motives the idea of securing favorable government action in redeeming the marshes and swamps of the country. It was decided that the society should retire from its field of work and leave the same to the Government, States, and other authorities and to individuals, and the society then disbanded. In 1903-1904 work against mosquitoes was undertaken by the State entomologist of Connecticut, Dr. W. E. Britton, who made careful mosquito surveys over the whole State and who published in his annual report for 1904 a careful and well-illustrated article devoted to showing how the mosquito nuisance can be abated. Since that time some active work has been taken up. In 1906 the board of health of Millburn Township in New Jersey secured the services of Mr. Weeks, and published a pamphlet entitled ‘‘The Mosquito Nui- sance in Millburn Township and How to Abate It.” ) EXAMPLES OF MOSQUITO EXTERMINATIVE MEASURES. rt At Worcester, Mass., an interesting crusade was begun early under the direction of Dr. William McKibben and Prof. C. F. Hodge. In Michigan work was carried on upon the campus of the Michigan Agri- cultural College. In Connecticut work was earlier done at Pine Orchard and Ansonia, as well as at Bridgeport, Branford, Fairfield, and Hartford; and in Maine at Old Orchard Beach. Excellent work was also done at a very early date at Lawrence, Long Island, largely against malarial mosquitoes, under the auspices of the board of health, working with an appropriation of $1,000 and with a pri- vately contributed fund of $1,678.84. A small crusade was also - carried on at an early date under the auspices of the civic committees _ of the Twentieth Century Club at Richmond Hill, Long Island. In the Southern States the boards of health of Atlanta and Savannah began work in 1903 and certain regulations were enforced. At Talla- dega, Ala., work was also begun in the same year. The excellent work done at Morristown, N. J., mer an improvement society in 1903 should not be forgotten. The work which has been done in Cuba and in the Isthmian Canal Zone has been elsewhere described. In the Territory of Hawaii work was begun in Honolulu in 1903 against the local mosquito plague. It should be stated that Anopheles mosquitoes are not known in Hawaii, and that although the yellow fever mosquito occurs there in numbers the disease has never been introduced. A general cam- paign, however, was begun under the auspices of the board of health and commercial bodies of Honolulu, and a meeting was held on August 15, at which a citizens’ committee of Honolulu was organized to work in cooperation with the board of health and to be supported by sub- scriptions. The president of the board of health was made chairman of the committee, and a salaried agent was placed in charge of the work. A campaign was continued for a year and a half, at a cost of nearly $3,000, donated entirely by public-spirited citizens. With the help of this fund the citizens’ committee demonstrated conclusively that it was possible to rid the city of the mosquito nuisance. Contin- uation of the work, however, on the basis of private subscriptions, was found impracticable, and later the work was turned over to the board of health and an item of $7,200 to continue the campaign for two years was proposed for the regular appropriation bill of that department of the territorial government at the session of the next legislature. The item, however, did not receive the indorsement of the administration in the interests of economy, and the board of health since that time has relied upon money from private subscrip- tions and carried on the work as actively as possible with the small amount gathered both in Honolulu and other districts of the island. In the course of this work mosquito-eating fish were introduced, as shown in the chapter on utilization of natural enemies of mosquitoes, 37713—Bull. 88—10——8 114 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. — CONCLUSION. It will thus appear that, considering the economic loss existing in the United States through malaria, nothing like the competent work has been done that should have been done, or really that should have been done in the past eight years within the territorial limits of the United States themselves. The United States Government has done admirable work in Cuba, for another people, and it has done excellent work in the Isthmian Canal Zone, but in its own home territory it has done nothing. State governments have done almost nothing, if we except the drainage work done in New Jersey. Malaria campaigns have been local and on the whole very unsatisfactory. The writer in 1903, in a paper read before the First Anti-Mosquito Convention in New York, December 16, after summarizing the work | which had already been done in different parts of the world, under the title ‘‘The World-Wide Crusade,” said: The main incentive to all this world-wide movement has been the prevention of disease. Probably nowhere else in the world has the motive of personal comfort entered into the crusade as it has in the United States, and we have already carried this aspect of the work much further than any other country. When we consider the enormous sums of money spent in the United States for luxuries, how much more should be spent for bare comfort and peace! Abundant evidence has been gained in the important work which has been done here and elsewhere during the past two years to show that mosquitoes in any definite region can be reduced to a point far below the danger line and quite within the comfort line, and in many instances it has been shown that they can be exterminated, at least fora time. This work will undoubtedly continue, but there are many communities which need constant prodding. The organization of the antimosquito forces in this convention which you are to hold will greatly stimulate public opinion, and will induce many of the indifferent to take a more sanguine view of possibilities, and perhaps more energetic action toward actual work. The same comparative indifference holds in other countries, and often even where work is begun under good auspices and with excellent indications it has failed of securing the best results. Maj. C. E. P. - Fowler, R. A. M. C., in his report on malarial investigations in Mauritius, 1908, points out that on that island the great fault has been in nonattention to small details, such as the formation of an organization to deal with the neglected surface water found in the small ditches along roadsides, in field drainage channels, and small collections of water in holes in the ground, and to keep up the larger work which has already been carried out. He states that no allow- ance or forethought seems ever to have been expended on keeping the work already carried through in proper working order. Where drains or ditches had been laid down only a few months previously he found | them time after time choked with vegetation and forming excellent places for Anopheles. The same thing was found in the rivers; the government had cleared them, but it seems to have been nobody’s - CONCLUSION. 115 business to keep them clear. According to this report, there seems to be a general impression among all classes of people, not only in Mauritius but elsewhere, that to carry on antimalarial work means the outlay of vast sums. People prefer to sit idle and complain that they have not the means to carry out the work. He shows that a few gangs of men can do a great deal in the way of ridding a district _of breeding grounds, and that their employment does not need a heavy outlay. ; | Looking over the whole field, it is easily seen that work in this direc- tion has hardly begun. There is so much to do in comparison with what has been accomplished or what has really been undertaken that it is almost discouraging when we consider that it is already eleven _ years since the function of mosquitoes in the carriage of disease was established. It seems as though such a discovery as this should have commanded immediate and widespread attention and should have caused the liberal expenditure of money from many sources in 'the effort to rid the human race of some of the most serious obstacles to ‘sanitary progress. Nain Page. Deere TOE MOSCULtOes 25. 22. 2 Le en pee Bek oe SL ee ee 68 _ Aédes calopus (see also Stegomyia fasciatd and Mosquito, yellow fever). breeding places... -.- AS SE EN SNe eas i BEE MIS hI Nard CoE ORANG REST 1 19-22 Rte eee = i 5 Papen es edrey Pe Shs Tole 8 ng ohn) A yore oY 92-93 protective liquids applied at night not effective fadgcruerte Bie: Coed 13 aan amundant on Wicken Beneioo3) 2.3 0S ate bea se eee Ls 27 cantator, distribution and seasonal appearance in New Jersey...-.......- bf sollicitans, distribution and seasonal appearance in New Jersey.......... 51 0 REISE) V8 LACE Te Sane iter Et OR Sy ae OE te a nd 79 teniorhynchus, distribution and seasonal appearance in New Jersey..-.... 51 Africa, German East, fish destructive to mosquitoes..................2-2.---- 70-71 Alabama, mosquito exterminative measures... .....--..---------.------- peas Veh AD SS Peeaanaseemedy for Mosquito bites. 24.2.2 s2s 2 eke ee 41 castor oil, and oil of lavender as protection from mosquito bites....... 12 Alge. (See Water plants.) Mmiretia mosquito exterminative measures. 2.50205: 2/2 Josey. le secee. lk ee. 98- 99 Pena aniremedy for mosquito bites... 6. 62222520. ob etc eee le 41 Amy] alcohol and kerosene against mosquito larve.............------------- 75 Pe eetctny OF MOZQUILOES. Lee ols .4. sk ea eee ee ie ee 67 Pe ree SIS AT JA AANA Soe ee Gases ete ad el OVE DY Dae 92-93 bifurcatus, breeding in-water of peat cuttings..........--...---....- 27 deterred from breeding by growth of Lemna arrhiza and LNT DEE teas yp OT ROLY EGO RLS TENE NY PE See AO ALLS BS 29 De Se eee bef 1S CE nut eg a Bo Sc ee AON ag Ee 98-99 NT LAS Gretel eta SEE) 4a BE A SARE LSD oe ear e SaP Coal Bae eM 65 Baa Ans Serer aN NO AA Ee See OL UAE SOOM IE TITS gates ii 100 Bebe Malate Umea tee oh TL Oe RNS Meee Pe Seay Lode 107-109 maculipennis (see also Anopheles quadrimaculatus). - as affected by fumigation with Mimms Culicide....... 34 deterred from breeding by growth of Lemna arrhiza and id, TRUER OR ONC a. Sele ee ee tae Sear Meet ae File Ra Pe 29 in peaty water and near peat piles.........-2....--.-- 27 unaffected by pawpaw or castor-oil plants. .....-.....- 24-25 nigripes, breeding in water of peat cuttings. .....-.......--------- 27 quadrimaculatus, breeding in places inaccessible to fish... ......-..- 72 in small town near New York City. .........-.. 109-110 Werdodenis GHei VIG IROAGUIGeS. .e.s se Sota see ee eee ae OS puma. t 66 Aquatic vegetation. (See Water plants.) Azolla. (See Duckweeds.) Baltimore, Md., mosquito exterminative measures.......-....--------------- 106 118 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. Page. Barrels, water, breeding places of mosquitoes...) 2... 2.7 1 eee 19, 20 | screening against mosquitoes... ....-..._.- 2.2 se 18-19 “‘Barrigudo.”? (See Girardinus caudimaculatus.) **Basil” plant as deterrent against mosquitoes. ........5.......--------.-.-- a Belgium, reclaimed marsh lands... 200.) 0.2224 ee sae bit Bergamot oil and kerosene as protection from mosquito bites............:...-- 14 Black flies. (See Flies, black.) Bottles, breeding places of mosquitoes... -....i2)....2. eee 19 broken, forming cheval-de-frise on stone wall, breeding places of MOSQUITOES 22 0...5 4 HEL nt eed Soe ee aoe 20 _ Boxes, tin and wooden, breeding places of mosquitoes.......................- 19 Brazilian fish, enemy of mosquitoes... ..-- 12.2.) 402 52 ee rel Brooklyn, reclamation of salt marsh-....2.5.... 550.052 2) gee 55 Buckets, fire, breeding places of mosquitoes: .-........1........ 21 ee 20 Cactus, cneey paste made from leaves as mosquito eee RPE cl 74 Obligonnis. drainage measures against mosquitoes. .....---.....---..--------- 44-47 reclaimed swamp lands: 2.2002... 77/9 Se ee te 54 Camphor spirits, as protection from mosquito bites.....................---.- 12 oil of citronella, and oil of cedar as protection from mosquito bites... 25. 2222 ea ge ee ee 1S Canopies and screens as protection from mosquito bites... 220.521 ¢5ee ee 14-18 Cans, tin, breeding places of mosquitoes: ):. 2.2.2.5. 2.2 {2222 a 19 Carassius auratus. (See Goldfish.) Carbolic acid preparations as mosquito larvicides..-.........---..-----.------ 74 resin, and caustic soda as mosquito larvicide......-...--...---.- 79 Carica papaya. (See Pawpaw.) | Carp, reported enemy of mosquitoes.......... site detect eer 63 - Cascarilla bark smudge against mosquitoes. .......--.----.----2.-----ce-e-e- 30 Cassia, oil, as protection from. mosquito bites.....)2.2.....2 7.2 22 ee 13 Castor oil, alcohol, and oil of lavender as protection from mosquito bites.....-- 12 plant as deterrent against mosquitoes..............---------+------- 23-25 Catch-basins in sewers, breeding places of mosquitoes..........--.--.---.----- 21-22 Caustic soda, resin, and carbolic acid as mosquito larvicide...........-...--- 79 Cedar oil, spirits of camphor, and oil of citronella as protection from mosquito bites: 2) 0246 ent ore ee Se aE Se UN 13 Center Island in Lene Island Sound, drainage measures against mosquitoes.... 9,43 Ceratopogon, capture in trap for adult mosquitoes. .........----....--------- 40 Cesspools, breeding places of mosquitoes.....-.2-2..-.:.2.-+-..-5- eee 20-21 Chaptico,.Md., mosquitoes and malaria. ..2......-..-.-.--7.2))3 ae 110 Chinaberry trees as deterrents against mosquitoes........-..--.-------------- 25 Chloral vapors as fumigant against mosquitoes........------------------------ 37 Chlorin gas as fumigant against mosquitoes. ...2...222-0/. 5-4-4... eee 37 Chloro-naphtholeum as mosquito larvicide. ....:...2:252)..--22 2. 5e2eeeeeeee 74 Chrysanthemum powder. (See Pyrethrum powder.) Citronella oil and vaseline as protection against mosquito bites.............-- 13 application to screens to keep mosquitoes from passing through. - 15 mutton tallow, black tar, and peanyroyal as protection against mosquitoes and black dia nLiewited if ee tats er 13 protection:from mosquito bites)... 22 2222. 25-8 - eee 13 spirits of camphor, and oil of cedar as protection from mosquito bites es cles vine oe el ho 13 Connecticut, mosquito exterminative measures...........---------------+- 112,113 Copper sulphate, impractical as mosquito larvicide............---------.---- 73 INDEX. 119 -, Page eet: wapractical ds mosquito larvicide.. 00020. 0. 002... ee. 74-75 Cover, cheap, for well-mouths or water barrels. ...........-..--...---.------ 19 Mrcsalpreparations as mosquito larvicides::/--.-. 22-0). .262-222 le. 74 Culex abominator, breeding in places inaccessible to fish...................-..- 72 SeUnnnS SOU LIVE IONGam Mpyt.oeeens oS Le SL 88 Gwarkindividuals, how calised::.¢- 2. 4.5. een LS Pee. 16-17 pungens (see also Culex pipiens). as affected by fumigation with Mimms Culicide............... 34 larve asphyxiated in lemna-covered water...............-.---- 30 pipiens (see also Culex pungens). ' breeding places. ........ PMNS A Sree Me ot aA BUS tT RS, bt 19-22 unaffected by pawpaw or castor-oil plants....................-- 24-25 a memepasciacus, breeding places... .... 605.2. ao ee Se ee. 19-22 destroyed in fumigation with Mimms Culicide......-. 33 Tuga eo ae se ep gi a eae arceg Git ce eet eh 92-93 Culcide, Mimms, fumigant against mosquitoes.................2.2-.+-----0-- 33-34 Culiseta annulata in peaty water and near peat piles.........................- 27 Cups of water used to insulate table legs from ants, breeding places of mosquitoes. 20 Caprmodon calaritanus, enemy of mosquitoes............-..2 225222020202. 2 2. 71 PeetinieA GMIMmesdUitOoeeas=s As ime tue EU ea | eee PADS Ye 66, 67 Cyermar eb in Trinidad, enemy of mosquitoes. ..-......:.25-.)2.--+-.-2.: 63 Cyprus, malarial mosquito larve destroyed by goldfish.............-.-------- 65 Dalmatian insect powder. (See Pyrethrum powder.) Datura stramonium. (See ‘‘Jimson” weed.) Derris uliginosa, decoctions and emulsions as mosquito larvicides............. 78 Memeo, enemy Of MOsSqUItOes) =. 2 l22c2.522 2220. eel ele lee. 66 Diemucilus tortosus, enemy of mosquitoes... ...-......2----22-.-----5------ 62 SnESUNePeASOIS “Oa ate LA eee oe be Lee es Ld MPmitmocreso! as fumicant against mosquitoes. .-....+..-.-.-----.2.5. 202-28. 37 Ditching machinery (see also Excavating machinery). used in drainage work in New Jersey....-....--..------- ‘51 meerammicr. Enemies Of MOSGUitOeset. cso... ee ee So beeen 62 Drainage investigations of U. 8. Department of Agriculture. ...............-. 55-58 measures in controlling mosquitoes: 2.2.2.2. 2.2 22. 2.202 fe. 42-53 Duckweed, rootless. (See Lemna arrhiza.) i Duckweeds (see also Lemna arrhiza and L. minor.) as deterrents against. mosquito larvee..../--...-..--.....2.0.----- 28-30 Egypt, work against mosquitoes along river fronts. .............--.-----.---- 88 Electricity, suggested use against mosquito larve.................--22.-2...-. 79 Enemies, natural, of mosquitoes, their practical use.................-.....--- 62-72 eon teelanmed marsh lamdss 206.305 Pood eos ee Se ina 53, 54 Enneacanthus gloriosus, enemy of mosquitoes...........-..........----------- 67 abesus, eneury Of mosquitoes Eto. Spee ee ey: 67 PeEEneratlarys, LOO Ol Tishtoc ie aclee ares eee re ee A 67 Hucalyptus as deterrent against mosquitoes....--.....--...--...-----22.0---- 22-23 Excavating machinery (see also Ditching machinery). for digging ditches and building levees, publication (5g Weed og Retake CLES Vy Oa a a 55-56 Federated Malay States, mosquito exterminative measures.........-. ND eke 89-92 Pamrasic, use of sulphur dioxid in disinfection... ....32.....02..22.2.0222.. 37 Fire buckets. (See Buckets, fire.) 120 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. — Page Fish and mosquitoes, Mr. Thibault’s observations on normal relation ......-.. "79 enemies of mosquitoes... .2.0 SSL kee edie Ld . 63-72 in- Brazil that destroy. mosquitoess:...< 22. ween See ae ee Witte 71 German East Africa that destroy mosquitoes.................-.--.---- 70-71 West Indies that destroy mosquitoes... ... ... 4... 52a eee 69-70 introduction into Hawaii to abate mosquitoes. ..-........-....- wit ys 2, 6b New Jersey to destroy mosquitoes....................-- 67-68 Flea bites, naphthaline moth balls as remedy .............--.----.-----+.--- 4] Flies, black, mixture as protection from. bites..:4....-..-.- d2. oop pee 13 Fly, house, as affected by fumigation with Mimms Culicide.................. 34 Footprints of cattle and horses in marshy ground, breeding places of mosquitoes. 20. Formaldehyde gas as fumigant against mosquitoes.............---..----- Ve Je Be ae Fountains, breeding places of mosquitoes.-....-..3...1.. Jw. t 54. ++ see 21 Fumigants against mosquiloes.<... 2): n-oss2sh.ceed sk dace eee oe 30-40 Fundulus (see also Killifishes). any" grandis, introduction into Hawaii to abate mosquitoes.............- 69 notatus, enemy of MmOsqUAMeS,)., .):~ 4.0 be oper ieee hee hie 63 sp., use against mosquitoes in New Jersey.........-....-..--------- 52 Furrows in garden containing water, breeding places of mosquitoes........... 20 Gombusia afimis, enenty of Mosquitoes:...-2.-52. 0... eek. 224 63, 65, 67-68 introduction into Hawaii to abate mosquitoes...............- 69 Georgia, mosquito exterminative measutes...4.-0.02- -.- 2-4: -.—eee eee 113 Germany, recent work against mosquitoes... . . Sees (oa ae 87-88 reclaimed marsh lands) -.2¢- 2234 Bese ssecas Ale 53 Girardinus caudimaculatus, use in destroying mosquito larve.................- TL,97 peciloides, enemy of Mosquitoes...) ~~ cic. uo ye 69-70 Gloves as protection from mosquito bites. -is5..3i5 2-24.52: 5-0..2 Seee id Glycerin. as remedy, for mosquito bites.......-... 2-252 24--/4ea er 41 Guat larve, food of fishes. 2 2 ..152)0.0. ganas den ee 67 Goldiish, enetry.of mosquitoes 4.5.0 4 Fo eric sti eee pee ¢ ¢2 oe 63, 64-67 Greece, antimalarial leagie) 322. 22002 edhe} ewes eps ee oo 104 Green Harbor, Mass., reclaimed marshes... ......).- - s.4-.5-.25- 96 ee 54 Habana, mosquito exterminative measures, 1901-2..........-- = senye eae 92-93 Hawaii, fish introduced to abate mosquitoes... .-...- 2.2 .2.)2i_s.42 95 .eoee 68-69 mosquito exterminative measures, J 2.4 .)..3. 2204. 3-442 113 Hay crops on salt marsh lands before and after drainage..-......-..--.-..-... 60-61 Heterandria formosa, enemy of mosquitoes. @s --..- 2 44.6 2)s.- ee 65-66, 67 Heteroditus, enemy of mosquitoes. 9. 22: 4542 54+ 45e a2) - os eee 66 Helland; reclaimed marsh landse's bioassay 53, 54, 58 Holy-water fonts, breeding places of mosquitoes........--.-.----------- Peet 20 Hot lamp chimney as remedy for mosquito bites..............--------------- 42 Tinos, reclaimed swamp Jands::... 20. Jot sje gases a. ues oe 54 India, conference regarding mosquito controle (250-2. ej = op 104-105 Indiana, reclaimed swamp lands...4.0...0.5-22)-24-. = Sees 54 Indigo lump, remedy. ior mosquito bites. . .(..5-./-2 445-042 4h.--5 4+) eee ee 41 Insect powder, Dalmatian. (See Pyrethrum powder.) Persian. (See Pyrethrum powder.) Iodin and saponated petroleum as remedy for mosquito bites and wasp stings. - 42 as remedy for mosquito: bites... 2nd. eeeeeeeles ~~ -> oe 41 Ismailia, mosquito exterminative measures...........----.----+------------- 100 Italy, drainage work near Milan, benefits therefrom. ...........--..---.----- 59 mosquito exterminative measures 5.02. Vein eee an ea 104 INDEX. 121 Page. Japan, experimental and protective measures against mosquitoes...........- 102-104 “‘Jimson” weed, powdered, as smudge against mosquitoes..-..............--- 37 Kerosene against mosquito larvee, early recommendations...-....-.........-- 7-9 and amyl alcohol against mosquito larve............--..-------.-- 75 bergamot oil as protection from mosquito bites. . piaak 14 apparatus for automatically and regularly ean it on ieataee at streams to kill mosquito larvae. ba) joao en tees 79-80 application to screens to keep mosquitoes from passing through...... 15 as i hag PI VAC ACR aide aya Sees, baat Soe eee ae iat i ao 75-77 drawbacks to use in tropical regions. ........- rie; provection from mosquito bitess,. 4." oe.) 2.828. 3a 4. eek relein, Ske 4 use in catching adult mosquitoes. ...........--- CU gt alt ea EER DEN 41 eemnivee aPaitiel MOsGUItOeS. s....-... 02.5222 -de eles oto s 2 te ae ene see 74 Killifishes (see also Fundulus). PEEaeIAC OT MANA UALOES AG Se Le ee eens Shin BUS Cae Sete 66-67 Klang. (See Federated Malay States.) Pee eatiers GCI VALUC..2 0 So ee Se enka sony eg cee se ok 53-62 Perviciaes aeainst mosquitoes... - 2.2.2. ..2--- 2. sna. san EE See pee 72-80 Larvicide used against mosquitoes at Isthmus of Panamassc.- 2.0.0... 042 79-80 Lavender oil, alcohol, and castor oil as protection from mosquito bites. .....-. 12 Lawrence, L. I., drainage measures against mosquitoes. ......-.-----.---- 43-44, 113 Leaves of broad-leaved water plants, breeding places of mosquitoes. ........- ZA Lemna arrhiza and L. minor as deterrents against mosquito larve...-....--..-- 29 Lemon juice as protection from mosquito bites................2.--..----.+--- 12 Long Island, drainage measures against mesqurtoes: Jo... be 9-10, 43-44, 47, 113 IE MRC OF MMOSGUILOCS 0.8 ois el ie nie eine eee Dee eles be 66, 67 Lutzia bigotii, enemy of yellow-fever mosquito..................-.------+------ 63 Reprise ANTS. ANG ANIMAS. 0.0. oso. ob bee Dt eee oe de ol a! 16-17 Mame, mosquito exterminative measures.......-.---.-...---22--2---+2--2-++ 113 Murs ere mane toes Im A leerig. .:2.-. 1.2.5... be Seka be eee eee es 98-99 (OLE TENS Care 1 EE SIRO Neg ep ME SS NADIR Se EE aaah IRS Bat aR 110 . oe Mitrosoinia 1 mosquitoes. —. 2... 2 o52-2ic hoe Ue a ee in oe ee 16-17 plants and animals... 2. 02.2.6 5. .2-12, ep 16-17 Midge larve, food of fishes-......-...-------- ‘ee bie de kine (ese. 67 ‘‘Millions.’? (See Girardinus peciloides.) Mimms Culicide. (See Culicide, Mimms.) Minnow, mud. «(See Umbra.) Mollinesia, introduction into Hawaii to abate mosquitoes..............-.-.---- 68-69 Mosquito bites, canopies and screens as protection.......-. ov ae Roe 14-18 sloves as protection.2. 2. -. --< <5 ” 2.222 2 oes eee eee 63 protective liquids applied at night not effective as repellents... - 22. 2:Cee eee Ree ee ee eee 13 INDEX. 123 Page. EPA AS es ee te Sah meer OR Se AT UA deo k ee 63-72 Mr. Thibault’s observations on normal relation.......-...- 72 malaria, experimental and protective measures in Japan.... 102-104 Fig) FECT gh, aS hs ies CE SA od ee Pat i ag 98-99 Chapircay’ Weltt Tae tig Sa Soe cee er gS 110 Cran ha ee oes Eek aera a ie Cen as 103 CRE el eens EN Se is RAE BE SMEAR 103-104 Cyprus lo hie es cen Rae, See a eae Mane hs freee 65 Federited' Malay States’. Sosy. Sy eo 89-92 Paormosa Ley ey eee ke Sar sO Ne Te (ef 102-103 Habana’ f900-V9G ree. Cera ews sae OMe ee 93 PANG 1 phar Gen io Nyt els Bet Ak as ea Ce BREE tat gd 104-105 Esminahig set eee ek es plik ee El WE as wets 100 UIE eS REE Diag Sloe < FU) Abeer aah gone PR eee te Tee a ks eee 104 G2 Oe LD Reg ar I VA a gan i Raa ot gy i ae Nt Ra 102-104 Japanese arinyy aes fo ee ee ee eee ae 102-104 Leipzig, Germany.....-.-- ER ata Sh tl Rs a 87 NES WEEE LHUISE c Shcnere ete cd tee Sete Ne ere Ns 114-115 ESOP VIIEY Ae Shar OS, ais Se WI Soe A Nicgely aA an se, 94 small town near New York City........-..-..-. 109-110 LEME SCl (SG 3 Ss le Ale Ak SO i a ae ge A 107-109 imipemmeetea er ee Se oS a ah aseS ot 105-111 Beem even in aalat oss. 22. 22 on. Ss OE 92-93 inthis or Paniarass coy RET ioe RY 94-95 Rieder rameirg sores ful eee 95-98 WicrrerUimnaatem sim atin) Soe Tea eons 100-101 Bepdered ioe catenmevadulta:. 2.2580 8 oe cts Ae 40-41 Benereonn trees) and plants. 26 2eoc Ss lel lk ec eset 22-30 Peainace measures im Controls: 22 tices 52. 24. Je 2 le nee See ee 42-53 pier enigy ane etiuneede ace 02 Ste es ee ee eel eos ey 30-40 household species, breeding places.................-----.-2----- 19-22 natural enemies, their practicaliuse.......2.22 22.2222 S26 fe 62-72 of New Jersey, salt-marsh species in different parts of the State. ... 51 organization for community work against them..-.......-.-....---- 80-88 preventive and remedial work, conclusion...................--- 114-115 MEUPOU TC HIOM yas 3 Uae ae elt os) 5 7-12 BEOEECHION ITORE DLCs 2! ee Seon pe eae ce oe shee PELE PETS protective liquids aeamse thems sls F Tel oe 12-14 REP CCNMOLAMDeKE Ae gee Fue. Nos aN See ee 41-42 merece Dreemun Piicesss tor sehos Poee OS ee eee es 18-19 RUG RCM ance NmMoAMIse Les se. pute es ee ne Oe Ek oo 30-40 Mutton tallow, black tar, oil of citronella, and pennyroyal as protection against BEEBE eCard) DIAC lonies <4 os ee ee I ee Se re ee eae 13 Naphthaline as remedy for bites of mosquitoes, other Diptera, and fleas... ..-. Al Seen Tesi NesOCin Ole <.0202 20. 2 NE oe 112 Nettings as protection from mosquito bites...................-222--2------ 15, 17-18 Netting, size of mesh with reference to mosquitoes....................-------- LW New Jersey, act to provide for abolishing mosquito-breeding places.......... 48-50 drainage measures against mosquitoes......................-. 47-53, 113 fish introduced to destroy mosquitoes..............1.....---.-..-- 67-68 salt-marsh lands, value before and after reclamation............. 59-62 ES BSCE ULE?) Pe eg a a ad ie a ee Ae 55 eee HEV AIREY oe. 2 ae Skew doce sk ke ee a le: 55 FT Page. Newport, R. I., mosquito exterminative measures..............-.-..--------- ill North Shore Improvement Association, drainage measures against mosquitoes 43, 111 mosquito campaign...........-.. 80-81, 84-86 Cerna mt UNUM. Jose Ss a sea ee ea phhwgds J40 2 26 viride as deterrént against mosquitoes..............2..222s2e-eceeeee 26 Ohio, reclaimed swamp lands:.2.)2 2.250. 2-014 -5 2 eiaie O oS; Lee Oil, crude. (See Kerosene.) | Meat Orange peel, dried, as smudge against mosquitoes................- ot ees 38 Oscillatoria, deterrent effect on breeding of mosquitoes....-............... Lag egg Oyster Bay, drainage measures against mosquitoes.....................-..---- 43 Panama, eae exterminative measures.) u.404--,uc +2201... - 2 93-95 larvicide. . 22... 50 RE ee ad 79,80 Pans in poultry yard, breeding places of mosquitoes........................- 19 Pawpaw plant as deterrent against mosquitoes. ..................-.2.--.---- 2 Peat as deterrent against mosquitoes......-. Liu oe aye ee rrr 2a: Pennyroyal, mutton tallow, black tar, and citronella as protection against mos- quitoes and black flies 2.) oA j24.¢.-- cee aeons Le ee 13 oil, as protection from mosquito bites....................2------ 12 Peppermint, oil, as protection from mosquito bites.............2.......--.--- 12 Perch, pirate. (See Aphredoderus.) ‘**Perch,’’ used to destroy mosquito larvee in water tanks....................- 63 Permanganate of potash, impractical mosquito larvicide......................- 73 Persian insect powder. (See Pyrethrum powder.) Petroleum. (See Kerosene.) saponated, and iodin, as remedy for mosquito bites and wasp stings. 42 Phinotas oil as: mosquito laryicide.. 2225.02 0.0 Cc eines (sr 74, 77-78 ‘“‘Phu-lo”’ plant, reported as repellent to mosquitoes. .... ies 4s i 25-26 PMSA” CRIES SS toe cite Basch ee eMC a hearer rete Sine ao eee) vs eeguuaneaens i, iam Pipes, breeding places ‘of mosquitoes..-.. 2.22.2: 2-.52.2 5.0125 Se 20 Pitchers, breeding places of mosquitoes...........------------- PE re Se: 20 Plants and trees reported as deterrent against mosquitoes.........---..------ 22-30 Peciliide. (See Top-minnows. ) Ponds, ornamental, breeding places of mosquitoes..........--.----------:--- 21 Port Swettenham. (See Federated Malay States.) Potassium permanganate. (See Permanganate of potash.) sulphate. (See Sulphate of potash.) Psorophora, enemies of other mosquitoes....-...-- ~~. +244) 220/42 eee 62-63 Puget Sound, tide marsh reclamation... 20.00 2022-55... .25.)529.. 54 Pumpkinseed. (See Sunfish, common.) Pyrethrum cinerarixfolium, cultayation.. 22... J. scene -c- ine ce ee eee 30-31 powder, as smudge against mosquitoes..............-...----------- 30-32 raseuny. CUULVALON pec vince foe ak le oe he or ze 30 Pyrofume as fumigant against mosquitoes Ble CLUS 2). oe er 34-35 Rain-water barrels and tanks, screening against mosquitoes Se {ky aoe 18-19 Reclaimed swamp lands, Galas SES BOR ii 270 aD sea 53-62 Reclamation work of United States Government).... 5.50.) .../../4. 55 Remedies for niosqiito. bites: 0... 425 bse ae ee as oe 2 41-42 Resin, carbolic acid, and caustic soda as mosquito larvicide........-....---.- 79 Ricinus communis. (See Castor-oil plant.) Rio de Janeiro, mosquito exterminative measures.........---...------------- 95-98 Reach, enemy of mosquitoes. io... oo one ccs Ue eee ee ebm ein eee ee 66 Roof gutters, breeding places of mosquitoes.........-..---------------------- 19 Salamanders, enemies of mosquitoes. . 2.24.2 -. 0.27. e eee ne 62 ey a INDEX. 125 Page. MmmmerrnortuiiGdarvicide.. 2.202) Oo We see eck as vee ie eh gee eae 78-79 | marsh lands in New Jersey, value before and after reclamation.........-. 59-62 SLSR Egat el arate et neetraligl Op ony: os hey 12a ng og A RE 14 breediny places apainst Mosquitoese 3. 0k os ke oe a ee ee oe 18-19 Screens and canopies as protection from mosquito bites...........-....------- 14-18 size of mesh with especial reference to yellow fever mosquito.......-..- 16-17 ETNA UE Co oc e SC foin Som ns dim nw ne sepa tiie. be a Mel a Uh Se eer icles 6 Ola 17 Sewer catch-basins, breeding places of mosquitoes...........-....------------ 21-22 traps, breeding places of mosquitoes.....- RAs ase ae Ne pate TOS 20 Sheepshead Bay, reclamation of salt marsh............- AES eG, ch aan MENA 55 Shiner. (See Roach.) Sridees against mosquitoes. ..............2-.02 2... .2.- 1a PACA AO *.... 30-40 pee oit. ds remedy for mosquito bites. - 00-022.) e. 82.2 b te eee eee 4] South Orange, N. J., mosquito exterminative Tmengures (20k Ul ice ina) Sania 82, 106 Staten Island, eiihase measures against mosquitoes.............-...--..--.-- 47 mosquito-exterminative Measures. : 2.2.2.2 5. Lys. ee eens 107-109 Stegomyia fasciata (see also Aédes calopus and Mosquito, yellow fever). . Alone Tver Aron isan MOV PL fesse g = -cisecel no hake pte 88 as affected by fumigation with Mimms Culiede) o.. te 34 dwarf individuals, how caused.......---- see URN ME! LAMY re! NS 16-17 pumeimenacns. enemies Of Mosquitoes... 62... 2562 de eee lI 63, 66 Stratford, Conn., drainage measures against mosquitoes. .......--...--------- 42 Sulphate of copper. (See Copper sulphate.) potash solution as protection from mosquito bites. bie Dal Lasagna 13 Sulphur dioxid as fumigant against mosquitoes..........--.-.-..----++---- .. 35-37 Sunfish, black-banded. (See Mesogonistius chxtodon.) Poaraimon enemy Of MOsGUITOES. 2525240 2) eos oe dk Lee oes 63 Meected tind G@estroy MIGsGIItOESs. 6. ose SL eae el este Se 66, 67 Swamp and overflowed lands of the United States, area, present and potential mailman COsi Of drainage: Jo. eae kek ue ee ee 56-58 lands near Milan, Italy, reclamation and benefits therefrom.......... 59 EREIE weer Hel TeCtaiMmed ys oN you yard eA cg Sle 53-62 mwanipe. araimnace im control of mosquitoes... 2.4... ..2.2 220222. 32. eo ee. 42-53 Tanks in water-closets, breeding places of mosquitoes...........-..-.-..-.--- 20 Pouin-water, breeding places of mosquitoes. -..22....24 52-220. -20 06 22. 19 RUreemIne AcdIMst MOSGUIUOES 2.025 .ou. al ee ee ease 18-19 supplying water to bath rooms in country houses, breeding places of RONG RL ORM son ee Ma URNS etc lS ae i Ui is 0s Go 21 Tar, black, mutton tallow, oil of citronella, and pennyroyal as protective liquid qeainst rresquitoes.and black dieses 622.5" oe... at in 13 pil, ds OrOtection against MOBQUILO MILES 0 e.g 0. oe SO eat 12 Thibault, James K., jr., observations on normal relation between mosquitoes 21 LES i) SSR USCIS ea Asa DESY, NST ea Nhe ME PR er PRP ok GLO 72 Top-minnows, enemies of mosquitoes................-.----+.-.-- 63-64, 66-67, 68-70 gor caicnmer adult mosguitoes..+ oc eso ke ee ee ee 40-41 Trees and plants reported as deterrent to mosquitoes.........-....-.-...-.-.. 22-30 Troughs of underground-conduit eras railways, suggested as breeding ees Of TGs MI TOCR: sen be eee sel ak Su iL rds Ee es Ste 22 water. (See Water troughs.) RM MeTaV GE INOS UILOCS 4 (0 eo ok, ceo tale ee Co ae SUS 66 United States, mosquito exterminative measures. .................---.--- 105-113 monnuiboestand malaria dowel ws ele Sl ee 105-111 swamp and overflowed lands, area, present and potential value, SSL ATEN OC Lae Baa a ae 56-58 > | ane ¥, A a] Bale) $, 126 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. __ Urns in cemeteries, breeding places of mosquitoes..................---------- Vaseline and citronella as protection against mosquito bites.................. ‘ Vases, breeding places of mosquitoes. ..........<2--.--.--4-- 20- eee Veils ag protection from mosquito bites. ..--.-......---.-1-44.- 25 14-15 Veracruz, mosquito exterminative measures... ....-.--...4---s-e55 eee 100-101 Verbascum. (See ‘‘Phul” plant.) Ee Vinegar as protection from mosquito bites.............----222-2.2-u8 Jasons 12 Washington State, reclaimed swamp lands........---.... ee 54 Washstands, stationary, breeding places of mosquitoes...-.......-......-- 20 Wasp stings, iodin and saponated petroleum as remedy.-.-...------...----- 3 42 Water accumulations under water tanks, breeding places of mosquitoes. .-.-.-..- 20 cup of grindstone, breeding place of mosquitoes.-.........-...-..-..- 19-20 plants deterrent to mosquito larvae... -- 22-22 5. 5.45065 eee i ee troughs for domestic animals, breeding places of pea - ne Heaerc eee 19 Wells, disused, breeding places of mosquitoes.....-.-------------<--------- 20 West Indies, fish destructive to mosquitoes. .....-..-----.----- enn». 69-70 Whitney, Milton, statement as to value of eee lands). 2 6: 2c oan ee 54-55 Wisconsin, reclaimed swamp lands. .. 22... -<..-:2024--.-82---2225 22 eee 54 Yellow fever and mosquitoes in Habana: ,. . 22... .-=a525~- + 25-2 See 92-93 Isthmus of Panama:...2:.) --.,...-4- 23 94-95 Rio de Janeiro... 4... -..- +. 2s ere 95-98 Veracruz. ...- ni pis ele bce 2 er 100-101 in Rio de Janeiro, measures of supression. -......-------------- 96-98 mortality therefrom, 1872-1909..-.-...----.--. 98 mosquito. (See Mosquito, yellow fever, Aédes calopus, and Stegomyia fasciata.) ; PeHOdICIY. .c5 525s. 6p ete - Dee ete ees eee 17 use of sulphur dioxid in disinfection....... Perr 37 O oo — 26 Side Se a ce? Se Ui et RG i * Pn eh ta ak, 4 ‘ x = s Pe ~~ ’ " ae S. DEPARTMENT OF AGRICULTURE, - ss BUREAU OF ENTOMOLOGY—BULLETIN NO. 89. ) L. O. HOWARD, Entomologist and Chief of Bureau. _ THE GRAPE ROOT-WORM So WITH ESPECIAL REFERENCE TO INVESTIGATIONS | IN THE ERIE GRAPE BELT FROM 1907 TO 1909. BY FRED JOHNSON anp A. G. HAMMAR, Engaged in Deciduous Fruit Insect Investigations. IN COOPERATION WITH THE OFFICE OF THE STATE ZOOLOGIST, PENNSYLVANIA DEPARTMENT OF AGRICULTURE. IssurED OcToBER 20, 1910. a ine bs Tienes b i a5 e: “= é - S: se: < a catkins SO oe CO URL Al\4AS 17 GOVERNMENT PRINTING OFFICE. 1910. y oF Se ¢ er a eS ig ete Se AM SR ae ak ee NERS : 3 B JUREAT Uv OF pyr TOMOLOG Y. : “wl eo SG ey 0. "omen: Entomologist and chr ee ex 2 oe: L. Martarr, Assistant Entomologist and Acting Chief in Absenc ates 4 FA Oe: ee Ope oe CLIFTON, Executive soa ae és cS ke A ate a As Taster, Chief Clerk. eee F. TE Gmirrennen, 3 in auelbe of cirtick crop and stored product sates se UA. D. Hopxins, in charge of forest insect investigations. - - 4 Honver, in charge of southern field crop. insect investigations. a M. Wensrer, in charge of cereal and forage insect ‘investigations. — 3 A. L. QuaintANce, in charge of deciduous fruit insect esiticleeie See > _E. F. Pars, in charge of bee culture. — hike. _D.M. Rogers, in charge of preventing spread of moths, , field work. ES £7 Rotza P. Currie, in charge afeditorial work, ni) Sout, Sea : Maney GoLconD, librarian. oie a pr hee Sacre Ties re “Deawvovs Frurr Ivsser Ivvesticarions, St y we : — pt, aos ae i. Quanwrancr, in charge. - ome geS a : Js ae een Daa, S. W. Poanan’ E. L. Shee P. R. tous A. 6. Ha 2: BRAUCHER, C. W. pas: a: R. ‘Hokron, ‘W. ORT, i ‘B. Gun, experts. . s me Sad rf ares, Ca ante ay Set Ee, Vs Scorr, C. H Gave, §: F. Zmuen, entomologieal assistants. a ie. . aed : ig a »Yye 4 .) : .! : ‘wt '%! r, > ee y = ; 7 af ha : ] : ; ru < < =e be a iy \ “ i. . ‘ a ree: 4 is ~ co f re aA ot at me he o} # 5 ‘ + by . EC ‘ is wih "y he od = ‘= i. is er ' J 2 ae a Ale > . ‘ o “ a, oe" Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE I. THE GRAPE ROOT-WORM (FIDIA VITICIDA). Fig. 1.—Female beetle ovipositing. Fig. 2.—Beetle on the lower sideof a grapeleaf. Fig. 3.—Egg cluster with average number of eggs. Fig. 4.—Grape cane showing eggs beneath the bark. Figs. 5, 6.—Full-grown larye. Fig. 7.—Pupa in cell. Figs. 8, 9.—Lower and upper views of pupa. Fig. 10.—Openings inthe ground from which beetles emerged. Figs. 3, 5,6,8,9, enlarged; figs. 2, 10, about twice enlarged; fig. 7, about three times enlarged; fig. 1, five times enlarged; fig. 4, natural size. (Original.) U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY—BULLETIN NO. 89. L. O. HOWARD, Entomologist and Chief of Bureau. THE GRAPE ROOT-WORM WITH ESPECIAL REFERENCE TO INVESTIGATIONS IN THE ERIE GRAPE BELT FROM LOOT TORTI 09: BY FRED JOHNSON anp A. G. HAMMAR, Engaged in Deciduous Fruit Insect Investigations. IN COOPERATION WITH THE OFFICE OF THE STATE ZOOLOGIST, PENNSYLVANIA DEPARTMENT OF AGRICULTURE. IssuED OcToBER 20, 1910. is af A “ive a Nl aR ee WASHINGTON: GOVERNMENT PRINTING OFFICR., : 1910. LETTER OF TRANSMITTAL. U.S. DEPARTMENT OF AGRICULTURE, BurEAU OF ENTOMOLOGY, Washington, D. C., June 8, 1910. Sir: I have the honor to transmit herewith for publication a manu- script entitled ‘‘The Grape Root-Worm, with Especial Reference to Investigations in the Erie Grape Belt from 1907 to 1909,” by Fred Johnson and A. G. Hammar, agents and experts, of this Bureau. The grape root-worm is by far the most serious pest of American varieties of grape at the present time and its ravages have caused a great depreciation in the value of vineyard properties as well as a marked reduction in the yield of fruit. The present report furnishes a careful account of the life history and habits of the pest, embodies a report on the work undertaken by the Bureau of Entomology in the spring of 1907 in the Erie Grape Belt, at the instance of vine- yardists, and provided for by Congress, and points out practical remedial measures whereby the vineyardists will be able largely to avoid future losses. : During the years 1908 and 1909 the work has been in cooperation with the office of the zoologist of the Pennsylvania state department of agriculture, as further detailed in the preface. I recommend the publication of the accompanying manuscript as Bulletin No. 89 of this Bureau. Respectfully, R. S. Ciirtron, Acting Chief of Bureau. Hon. JAMEs WILSON, Secretary of Agriculture. 2 PREPAC. The grape root-worm, the subject of the present report, is an insect which during the last ten or fifteen years has attracted much attention on account of its ravages in vineyards along the southern and eastern shores of Lake Erie, comprising in general the grape- growing territory of northern Ohio and the Erie and Chautauqua grape belts of Pennsylvania and New York, respectively. American varieties of grapes, exclusively grown in the above-mentioned regions, have heretofore been singularly free from insects attacking the roots of the plant. The Phylloxera, so destructive to the roots of vinifera varieties in Europe and in California and elsewhere in the United States where these are grown, fortunately does not seriously injure varieties of American grapes. The grape root-worm, however, has come to be recognized as the most serious of the two hundred or more species of insects in the United States which feed Sra or indirectly upon our native grapes. The destructiveness of the insect in the Erie grape belt in the general neighborhood of North East, Pa., led, through the represen- tations of prominent vineyardists, to a ee by Congress for an especial investigation of the pest by the Bureau of Entomology. This work was begun in the spring of 1907, and a laboratory was established at North East, Pa., which place has been continued as headquarters during the years 1908 and 1909. During the latter _ two years, by contract entered into between the Hon. James Wilson, Secretary of the United States Department of Agriculture, and the Hon. N. B. Critchfield, secretary of agriculture of the State of Penn- sylvania, the investigation has been in cooperation with the office of the state zoologist of the Pennsylvania department of agricul- ture. The work has covered a wide range of investigations, in- cluding a thorough inquiry into the life history and habits of the insect, large-scale experiments with remedial measures, and the demonstration of the effectiveness of measures known to be of value, including the renovation and improvement of young and old vineyards already seriously injured. _ Mr. Fred Johnson has been in immediate charge of the field work during the entire period of the investigation, and was assisted in 1907 by Messrs. W. B. Wilson and P. R. Jones, the former engaged in field work and the latter in life-history studies. During the years 3 ati a 4 THE GRAPE ROOT-WORM. 1908 and 1909 Mr. A. G. Hammar was detailed to the grape root- worm investigation and devoted his attention particularly to life- history studies, assisted by Mr. E. Selkregg. Prof. H. A. Sur- face, state zoologist of Pennsylvania, assigned, as a representative of the Pennsylvania department of agriculture, Mr. F. Z. Hartzell during 1908, and Mr. H. B. Weiss during the year 1909. These gentlemen assisted in field operations and rendered most efficient service, contributing much to the success of the investigation. In the present report Mr. Johnson has prepared the manuscript detail- ing results of field experiments and Mr. Hammar the manuscript detailing results of life-history studies, and most of the illustrations. The results obtamed by this study, as detailed in the subsequent pages, will, it is believed, furnish entirely practicable and economical measures for the control by vineyardists of this serious insect pest. It is essential, however, in order that satisfactory results may be secured, that the recommendations given be followed in a thorough and sil manner. The authors desire to express Tee thanks to the following vine- yardists of North East, Pa.: Mr. George Blaine, Mr. W. S. Wheeler, Mr. R. Davidson, Mr. W. E. Gray, Mr. H. S. Mosher, and Mr. A. I. Loop, for their direct assistance in the conduct of this investigation by placing large blocks of their vineyards at the disposal of the Bureau of Entomology for several seasons and assisting in conduct- ing experiments thereon. They also wish to thank the large number of vineyardists whose interest in the work during its progress has -been a source of inspiration and gratification to them throughout this period. A. L. QUAINTANCE, In Charge of Deciduous Fruit Insect Investigations. CONTENTS. IeTEME Re eve te Se i en sobs os. Bey st MBEER Wee eer tro 2) Fe ees. ee eee eee bs a eee ee RemPeM CGE ODIO... 2... 22... rl eect EELEDS LL Ses EOS es I ar eo Pn ee ee Siaracter of injury and destructiveness...........:..-.0..----2-..---- Beetles related to the grape root-worm beetle..............--..-------+-- Beetles frequently mistaken for the grape root-worm beetle...........-- UST To: Ln ERE iE a a I yc ee oe BEB vc Slee Ste Se ge AE Srl ce ee a RR er nt ET ON Sera re IN Py lol A lobe ae nian Se iels, eine e's PIT ne ee si fy ae Ng ok ee ye, oe be Sake The adult or beetle........ Ser ee i cy kee Soke OB ERIE a mere Ae ee ye te ooo bed Sememrmmiieorminectio: s) 2.0 i628. oe ie See ee eee ees ie process and time of emergence........---...--2-224.-4--- Mernation in the time of emergence._...:-..-...222/.2.-2-224- Feeding before and after egg deposition...........-......------ Mating and its bearing upon egg deposition...........-..-.--.-- PimcesrokeperdepositiOm: -.. 00/22 os. st Fae ae eet 965.2 Variation in the number of eggs per cluster.............------- Number of separate ovipositions by individual females .......... ...-. Number of eggs deposited by individual female beetles. ....... The oviposition period for the season of 1909.................-- Longevity of male and female beetles.......................-.- EET Al ee oe ee sg eat A eR Ae OAS ee WA peg Piedbarniom period, of thelere. 7. 02222.252522424 2 h32a5 22.0. 228 ote EISEN EE i PS IR SR Bee OR Oe acm ie a Cra Vitality of the newly hatched larva........... bc ge eee Weer Feeding and development of the larva before wintering.....--.- Wintering of the larva in an earthen cell.........-....-.---.-.--- Sprne feeding or thedarvaes 6400 ee 2 dae Feeds de. Time-and making.of the pupal-celll.s 2.22. tse. 62552252229. 52225 ibe POst-lanVval Stabe: Jos se. cere fae ee Poe eet eee ee SE TEL) Bp RR ee a OC oe che ao ON a ee ae Pine PLOCess Of PUpAavlON. 22 s..so4 Meee ce ie eee oct eee Postion. of the pupa im the eell-{j-6..2 2 222222 ok ese: Time of pupation in the field and in breeding cages ..........-- Buractoncat tie pupal. perlodss. ga aa= 602 Ses so Poses cas tS Life cycle of the grape root-worm as determined by rearing..-.-..-.-- Seasonal variations in the life history of the grape root-worm....-.-...-.-.-- Reamne and experimental methods: ..-..4....225.2.--2..2-5.22-%- Summary of life-history studies of the grape root-worm...........-- | 6 THE GRAPE ROOT-WORM. Life history of Fidiobia flavipes Ashm...............------- 22222222. | A dipterous parasites. .25..:.0-2..00..0..1.2.. 2 eee Double parasitismy....225..2 7220 be eee ee hae Vineyard conditions in the Lake Erie Valley......... fon ace: ee Remedial measures for the control of the grape root-worm.............. a) Wee Evolution of preventive measures...-.......-..-..-.. 5. _ 2 ee Cultural methods forthe destruction of pupz................. 222399 Effect of poison sprays on the beetle in the field......................... Cage experiments with poison sprays against the beetles. ..............-. Field experiments with poison sprays against the beetles................. Comparative effectiveness of arsenate of lead and arsenite of lime......... Results of vineyard experiments with poison sprays...............--...-. Results of vineyard renovation experiments....«--.. 2.2.2 sabe. eee Renovation experiment on an old vineyard ........<.. 2-05-26 eee Methods of obtaining and recording results..................-.--- Renovation experiment on a young vineyard..........-.-..-.----.--- NPPayss ob Sok eos os Ss Aisa e cw skci See eee ce ose Se Arsenical poisons... 22 2.2loo.35.00 0. 18s eS. Combining insecticides with fungicides....-.......=-.22 2S Preparation of Bordeaux mixturée_.-......52..-.-2.0t 2.222 Plants for preparation of the spray mixture. -......: - 525.4222 eee ee ‘Time of application Of sprays... 5-8 cece 4c. he See «as ee Number of spray applications. .+.5..:2-.5..2.52.4... 2-2 Pressure to be maintained in spray applications...........-.----.---- Spraying apparats. +. 222. Jl ses. eo. ee be eee ae (eked Horse-power sprayers.....-..--20-2 222... 2 ekie Ue oe Gasoline-engine sprayers.«..<-+.se< e260. be we. tn ee Compressed-air O@tiise< 2c ode 2b s4be oie es lieen tee eee Lalicgaen Carbonic-acid-gas:spttiyers. ......2.6./2. 4/0226. chk ee Hand pumps../25.. 25. Whe. pel vce ed eles ee 4 oon ee The €are of spraying apparatus..i: o2 24-422. 002 -1-Siced 4. ae is Nozzlé adjustment... s2s..20 22 22222 ge. 2b ere Novzlescgios- 62 ae ek Se ok ye eee ee eee Recommendations. c2.2.. 252/25. 22 foe .t eed s2 4 ee eee Destruction of the adults or beetles..2.2.¢-es-262 4.4.5.4 ee Destruction of the puppet. 2. dtac (240 sede be see eee oo eee General treatment of infested vineyards.-.........---- Peer Bibliosmply - i224 2250... Le a is ts ees aoe bee Puate I. II. LE, VII. VIII. IX. ILLUSTRATIONS. PLATES. The grape root-worm (Fidia viticida). Fig. 1—Female beetle oviposit- ing. . Fig. 2.—Beetle on the lower side of a grape leaf. Fig. 3.— Egg-cluster with average number of eggs. Fig. 4.—Grape cane, showing eggs beneath the bark. Figs. 5, 6.—Full-grown larve. Fig.7.—Pupaincell. Figs. 8,9.—Lower and upper views of pupa. Fig. 10.—Openings in the ground from which beetles emerged. Page. cio sie 8 ESA ae teh ey ey Se oe ee ery Be Frontispiece. Feeding marks on grape leaves, made by the beetle of the grape root- worm. Fig. 1.—Appearance of fresh feeding marks. Fig. 2.— Feeding marks which have become enlarged with the growth of the Feeding marks on the larger roots and underground part of the stem of a grapevine by larve of the grape root-worm, resulting in the cornet i eupy maliniGes. ah ert Beals oS Oe et ee ab be OL . Destruction of root fibers by larvee. Fig. 1.—Five-year-old grapevine with normally developed root-system; enlarged portion showing root fibers. Fig. 2.—Four-year-old grapevine, showing result of feeding by larve of the grape root-worm..........-..---------.-- . Ridge of soil under trellis. Fig. 1.—Vineyard view in the spring, showing ridge of undisturbed soil under the trellis. Fig. 2.—Vine- yard view, showing ridge of soil under trellis as formed at the last cultivation of the preceding summer. North East, Pa............ . General view of Mr. Roscoe Davidson’s vineyard at North East, Pa., where spraying experiments against the grape root-worm were con- ducced dumm 1907, 1908, and 19092. eet. eh betes eee eee os Views of experimental plats in Mr. Roscoe Davidson’s vineyard at North East, Pa. Fig. 1.—Retarded growth of vines in the un- sprayed plat. Fig. 2.—Vigorous growth of vines in the sprayed Se ese Se ork Fk eek 2 hse each tees LR Aes ee eee oo Views of the Porter experimental vineyard, showing comparative growth of the vines in 1907 at the beginning of the experiment (upper figure), and in 1909 at the end of the experiment (lower RECHT Cc WN GREG Mis entra ays ates 8 Ale’ jk oa sl ie he ie este Condition of fruit on vines in plats of the Porter experimental vineyard. Fig. 1.—Average condition of berries in the untreated plat. Fig. 2.—Average condition of berries in the treated plats. INGrubrMagt, (Pais MOOD sak eee aa 35h a ee i ek ee ae ds . Spraying outfits for vineyards, in use at North East, Pa. Fig. 1.— Spray-mixing plant. Fig. 2.—Gasoline-engine sprayer in opera- tion. Fig. 3.—Compressed-air sprayer. Figs. 4, 5—Horsepower GRO CIted SpIaAVersw i. . 22 aso ue ie toes o eee aine.cue Sue eae sous oa so TEXT FIGURES. Fia. 1. Map showing distribution of the grape root-worm (Fidia viticida) .....- 2. The California grape root-worm (Adozus obscurus): Adult or beetle. . - - 3. The grapevine Fidia (Fidia longipes): Adult or beetle.........-...-- 14 14 16 62 70 74 80 80 86 Fia. 13. 14. 15S. 16. gy 18. 19. 20. 21. 22. 23. 24. 20. 26. 27 28. 29. 30. 31. . The grapevine flea-beetle (Halticachalybea): Adult . The rose-chafer ( Macrodactylus subspinosus): Adult or beetle . The redheaded Systena (Systena frontalis): Adult or beetle . The grapevine Colaspis (Colaspis brunnea): Adult or beetle . The grape root-worm (Fidia viticida): Larva and details . The grape root-worm: Pupa and details . The grape root-worm: Aduit or beetle . The grape root-worm: Structural parts of beetle..................... . Diagram showing time and development of a single individual of the THE GRAPE ROOT-WORM. a ad grape root-worm under average conditions, as observed in 1909, at North ‘Hast, Paro: 2252 ooo... lee ea oe ee Curve showing time and relative emergence of beetles of the grape root- worm from the ground in rearing cages at North East, Pa., 1909... ... Curves showing variations in time of emergence of beetles of the grape root-worm from different kinds of soil. From rearing cep durmeg 1909 at: North East, Pa... .. 0422. 2¢hs 2-2. 6. Curve showing time of egg deposition and relative abun of eggs laid in rearing cages by beetles of the grape root-worm at North East, Pai, during 1909. 00952522 eke a ce Diagram showing variation in time of emergence of beetles of the grape root-worm during 1907, 1908, and 1909, at North East, Pa........... Temperature curves showing the daily records of the maximum and minimum temperature during the breeding period of 1909 at North Portion of the outdoor rearing shelter used in the rearing at insects at North Hast, Pa., durimg 1909 .. 2022-22 2. ¢ 2222.2) ee Wooden-frame fee with glass bottom and wire-screen cover used in studying the pupal stage of the grape root-worm beetle............. Earthen pot with glass cyclinder used in rearing the grape root-worm. . Rearing cage with glass sides used in the study of tie larva of the grape Toot-worm beetle 23-2222 20k 2 Fu. 2 22 eee Earthen pot with wire-screen cover used in rearing. the grape root- mpearny.: SE S PR e IC aA Oe S r Diagram illustrating seasonal history of the grape root-worm as observed during 1909'at: North Mast;’Pael..22-. 22... .-. 2 ee Fidiobia flavipes, an egg-parasite of the grape root-worm: Adult and enlarged antenna, 2-12.42) koe ee Diagram showing the relation between the three generations of the Fidiobia parasite and the relative occurrence of eggs of the grape root-worm at North East, Pa.; during 1909 ... .. |.) 22222252 Larva of an undetermined insect parasite of the eggs of the grape root- ORE Toho Se ee ME Per ad 2 SN gS: oo er Lathromeris fidix, an egg-parasite of the grape root-worm: Antenna and fOrewine...ibid.e vss lyleckievehecks+.J 0S) 2 ee 23 24 25 32 42 43 45 45 46 47 48 49 52 59 56 57 Horse hoe used in removing the soil from beneath the trellis in vine- — yerdsio ui: oy dete ee be I Young grapevine, unsprayed, showing extensive feeding by beetles of the grape toot-worm. North Hast, Pa., 1909-: 2... .-./- 22 32-2eeee Young grapevine sprayed with arsenate of lead against the beetles of the erape root-worm; North East, Pa., 1909... .......-224-e-eo2aeeee A. large nozzle of the-cyclone type .-. 2. 222g. 5. 8s ee ee 61 66. 87 89 THE GRAPE ROOT-WORM WITH ESPECIAL REFERENCE TO INVESTIGATIONS IN THE ERIE GRAPE BELT FROM 1907 TO 1909. INTRODUCTION. During the past decade the insect Fidia viticida Walsh (PI. JD), a chrysomelid beetle known to the vineyardists of the Lake Erie Valley as the ‘‘erape root-worm”’ beetle, which in the larval stage feeds upon the roots of the grapevine, ne become by far the most destructive insect pest attacking the grape in that region. The following pages present the extent and findings of an investi- gation conducted at North East, Pa., during the seasons of 1907, 1908, and 1909. These investigations were undertaken in order to make a thorough study of the life history and habits of this insect, to conduct experiments with a view to its control, and to make field experiments to demonstrate the practical commercial value of those methods giving greatest promise of effective results. Since the grape root-worm is a grape pest of long standing, a brief résumé of its history is given, both from the standpoint of entomolog- ical classification and from that of the development of remedial measures for its control. Its origin, distribution, and food plants are considered, brief de- scriptions of allied beetles and of those beetles found upon grape- vines likely to be mistaken for the grape root-worm are given, and also a description of the character of the injury to the vine wrought by the insect and the extent of its destructiveness. The technical descriptions of the different ages of the insect are followed by a presentation of life-history studies involving many careful experiments with numerous individuals. These studies were . undertaken to determine the length of the stages and the time at which the different changes occur. This work was conducted for ‘three consecutive years with a view to determine the effect, in the development of the insect, of seasonal variations due to varying climatic conditions, and it has been productive of very interesting results which have an important bearing on the time of application of remedies. Soil conditions and altitude of vineyards are also con- sidered in this same relation. 9 10 THE GRAPE ROOT-WORM. Preceding the discussion of remedial measures a brief summary is given of the conditions in vineyards in the Lake Erie Valley since their invasion by the grape root-worm, dealing with the age and con- dition of vines at the time of its advent, the increase in area of new vineyards, the insect’s comparative destructiveness to old and newly planted vines, and the relative responsibility of the pest for the fluctuations of crop yields during the past decade. — ; Cultural methods are considered with special reference to the destruction of pupz in the soil. In the presentation of the data dealing with poison sprays for the destruction of the beetles, details.of experiments are given, first, to show the efficiency of arsenicals as a direct killing agent of the beetles in confinement and also in the open field; second, to show the rela- tive value of arsenate of lead and of arsenite of lime; and, third, to show the cumulative value of poison-spray applications on large vineyard areas, both in crop yield and in vigor of vines as a result of three consecutive years of this treatment. Following this experimental data on poison sprays the details are given of field demonstration experiments with two run-down vine- yards, conducted for three consecutive seasons. One, an old vine- yard of about 10 acres, the other a young vineyard of about 5 acres. The condition of each of these vineyards at the time the experiment was undertaken is described and the plan of treatment—covering general vineyard practice, such as pruning back of badly injured - vines, fertilizing, cultivation, and spraying with arsenicals—is given, accompanied by the collected data showing the results of this treat- ment in lessening deposition of eggs by the grape root-worm beetles, in the diminution of grape root-worm larve in the soil about the roots of the vine, in the increase in crop yield, and in the general effect of this combined treatment upon the health and vigor of the vines. The remaining pages contain a brief discussion of arsenicals as stomach poisons against the grape root-worm beetles, the desirability of combining them with a fungicide when spraying for this pest, spraying methods and spraying machinery as related to vineyard treatment, and recommendations as to time and manner of making applications. HISTORY. The first record of the beetle, Fidia viticida, the adult of the grape root-worm, as a pest of economic importance upon grapevines was made by B. D. Walsh in 1866 in the Practical Entomologist (see Bibliography), and it is also to him that we are indebted for the first description of this species of the genus Fidia. Yet as far back as 1826 this insect appears in entomological literature under a variety HISTORY. 14 of names. The first reference we find to this species is in M. J. Sturm’s Catalog Insecten Sammlung, at that date (1826) under the name of Colaspis flavescens. Under a later catalogue (1843) by the same author it is listed under the name of Fidia lurida Dej. Dejean, in his Catalogue des Coléoptéres (1837), names two species, Midia lurida Dej. and Fidia murina De}. The genus Fidia was first characterized by Baly in 1863, who used the name Fidia suggested earlier by Dejean. Crotch, however, in 1873, described this insect under the name of F’. murina and Lefevre, in 1885, described it under Ff. lurida. In 1892, when Dr. George H. Horn revised the Eumolpini of Boreal America, F. murina and F. lurida were found to be synonyms of Fidia witicida as described by Walsh in 1867.7 Since 1866, when this insect was first reported as occurring in destructive numbers in Kentucky, it has developed into the most serious insect infesting vineyards east of the Rocky Mountains. At that date only the adult form and its injury to the vine by feeding upon the foliage was known. Walsh assumed that the larval habits of the pest were similar to those of the grape flea-beetle (Haltica cha- lybea Ill.), and that it would be found the most destructive in this stage feeding upon the foliage. In the former assumption he was correct, for it is the injury of the larval form which is inimical to infested vines, not upon the leaves, however, as Walsh supposed, but upon the roots, as shown by later investigations. The year following, the insect was reported from St. Louis and Bluffton, Mo., and in 1868 Prof. C. V. Riley, in his first report on injurious and beneficial insects of Missouri, mentions it as ‘‘the worst foe to the grapevine in Missouri.”’ In 1870 specimens were received by Riley from Bun- ker Hill, Ill., and in 1872 Mr. S. H. Kridelbaugh reported it present in lowa in injurious numbers. Tt was not until 1893, however, that some light was thrown upon the earlier stages of the pest. In December of that year Prof. F. M. Webster, then entomologist of the Ohio Agricultural Experiment Station, received larve from the vicinity of Cleveland, Ohio, where they were said to occur in great numbers about the roots of vines. Later there developed from these larve the complete form which proved to be the beetle Midia viticida, hitherto the only stage of the a'The validity of the technical name of the grape root-worm (Fidia viticida Walsh) might be questioned. The names lurida and. murina were used previous to viticida, but as nomina nuda, the specific description was first given in 1867, when Walsh described the insect under the name Fidia viticida. Baly in 1863 characterized the genus and designated lurida as the type of the genus, though the species under that name had not yet been described. The specific name viticida Walsh has the priority, since the valid name murina was first used in 1873 by Crotch, and lurida in 1885 by Lefevre, both writers using the early manuscript name of Dejean. 12 THE GRAPE ROOT-WORM. . ‘ insect known to entomologists. During the season of 1894 Professor Webster made a detailed and accurate study of the life history of the insect, described its immature stages, and made numerous field experiments to determine effective methods of control, which are referred to in another part of this bulletin. , In 1896 Prof. J..T. Stimson recorded injury caused by this insect in Arkansas. Dr. John B. Smith, in his Catalogue of Insects of New Jersey, 1900, reports its occurrence throughout that State. Dr. L. O. Howard reported it from Bloomington, Ill., in 1901. In later years the insect appeared as a pest in the grape region of Penn- sylvania and New York, where from 1900 to 1906 it was the subject of detailed studies, treating both of its life history and remedial measures, by the late Prof. M. V. Slingerland, of Cornell University, Ue. Wa (SSi MAAR ‘ * ' H H Fic. 1.—Map showing distribution of the grape root-worm (Fidia viticida). (Original.) and by Dr. E. P. Felt, state entomologist of New York. The reports of the investigations by the former are embodied in the bulletins of the entomological division of Cornell University, and the publica- tions of the New York State Museum contain reports of those made by the latter; all publications of these two investigations are listed in the bibliography accompanying this bulletin. ORIGIN AND DISTRIBUTION. The grape root-worm has at present been recorded only from. North America, and it is without doubt a native species, feeding | originally on wild grapevines, as it still does to some extent. The insect is widely distributed in the Mississippi Valley and in the Eastern States. The map (fig. 1) shows the distribution as recorded at present. FOOD PLANTS. 18 In literature the insect is reported from the following States: Arkansas (Riley, Howard, and Stimson); Illinois (Walsh and Riley); Iowa (Kridelbaugh); Kansas (Webster); Kentucky (Walsh); Mis- souri (Riley); New Jersey (Smith); New York (Lintner, Slingerland, and Felt); Ohio (Webster); Pennsylvania (Slingerland and Felt). According to records of the Bureau of Entomology the insect occurs in Illinois, Kentucky, Michigan, Mississippi, Missouri, New York, North Carolina, Ohio, Pennsylvania, Texas, Virginia, and West Virginia. In the collections of the National Museum are ‘specimens from the following States: District of Columbia, Illinois, Kansas, Maryland, ~ Missouri, Nebraska, New York, North role Ohio, Pennsyl- vania, Texas, and Virginia. From the following localities it has not yet been recorded, but probably does occur as these are neighboring sections of infested places: Southern parts of Indian Territory, Tennessee, and Wiscon- sin; northern parts of Alabama, Georgia, (eo patea and South oe FOOD PLANTS. From early records of this insect it is evident that the beetle of the grape root-worm was observed feeding upon wild grapes long before it was known to infest cultivated varieties. Riley reported the beetle feeding upon the leaves of wild grapes and upon the red- bud (Cercis canadensis). Several writers have found it feeding upon the foliage of the Virginia creeper (Ampelopsis quinquefolia). With the extensive cultivation of improved varieties of native species of grapes, the insect has found in these a more available food plant. The larval form and its underground habits became first known through its abundance and destructiveness in vineyards. On the wild grapevine the grape root-worm does not breed in extensive numbers, because the conditions in woodlands are less favorable than those existing in vineyards. The chances for the newly hatched larve to reach the roots of the wild grapevine are greatly limited, since the plants spread their aerial growth exten- sively and in such a manner that the parts of the vine above ground are not directly above the root system. Under such conditions numbers of the larve on dropping to the ground do not reach the needed food plant and probably perish. A single female beetle, _ however, lays a considerable number of eggs, and out of the many hatching larve the chances are that always several will survive to ‘perpetuate the species. In the course of this investigation at North East, Pa., several attempts were made to locate the larvz on roots of wild grapevines, but in no instance were larve found or any signs of feeding observed on 14 THE GRAPE ROOT-WORM. the roots. In the breeding work, however, larve. were reared on wild grapevines, which shows that it is possible for the larve to exist on these plants. In 1909 larve hatching July 26 were placed in large earthen pots (fig. 22) in which, some time previously, wild grapevines had been planted. On examining the cages in the fall of the same year (1909) a number of larve were found to have attained their normal growth, as compared with other larve reared under similar conditions on cultivated vines. CHARACTER OF INJURY AND DESTRUCTIVENESS. The injury wrought by this pest on the grapevine occurs both above and below the surface of the ground; however, by far the greater damage results from its work upon the roots. The injury above the ground is done by the beetles; that upon the roots by the Enns or larve. The first intimation that the observant vineyardist is likely to obtain of the presence of this pest upon his vines is the appearance, late in June or early in July, of chainlike markings upon the upper surface of the foliage (Pl. Il). These markings are made by the beetle. Ordinarily this scoring of the leaves is not sufficient to materially affect the health of full-grown thrifty vines. Where the beetles are very numerous, however, and the foliage sparse, it not infrequently happens that the leaves are so badly scored that in a short time they take on a brown appearance and hang about in -shreds. In the case of newly planted vines (fig. 29) extensive feeding by the beetles greatly retards the growth of the young plant and proves a great obstacle in the starting of a new vineyard. On the thick-leaved varieties of grapes, such as the Concord, Worden, and Niagara, this feeding does not extend through the heavy pubes- cence on the lower surface. The pubescence holds together only a short time, however, and soon either dries out or is torn apart by the growth of the leaf. On the thin-leaved varieties, as the Dela- ware, and on the wild species of grape, holes are eaten entirely through the leaf, usually assuming the characteristic chainlike irregu- larity of form. It is, however, to the larvee of this pest feeding upon the roots of the vines that the direct cause of the injury and death of so many vines is due. The work of the larve upon the roots may be recog- nized, when the vines are removed from the soil, by the absence of root fibers, by channels along the larger roots, and by pittings on the main trunk. (See Pl. III.) Vines that have become well established before the infestation by larve will sometimes withstand the attack of a considerable number of grubs, especially if the soil is rich and has been well tilled. The evidence of continued heavy infestation is indicated by absence of fibers upon the whiplike roots Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE II. FEEDING MARKS ON GRAPE LEAVES, MADE BY THE BEETLE OF THE GRAPE ROOT-WORM. Fig. 1.—Appearance of fresh feeding marks. Fig. 2.—Feeding marks which have become en- larged with the growth of the leaf. Natural size. (Original.) Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE III. FEEDING MARKS ON THE LARGER ROOTS AND UNDERGROUND PART OF THE STEM OF A GRAPEVINE BY LARVA OF THE GRAPE ROOT-WORM, RESULTING IN THE DEATH OF THE PLANT. LOWER FIGURE NATURAL SIZE. (ORIGINAL.) BEETLES RELATED TO GRAPE ROOT-WORM BEETLES. 15 (Pl. IV, fig. 2, in comparison with fig. 1) extending from the main root a distance of several feet. The extremities of such roots are frequently dead and in a decaying condition, and the portion near the stem 18 much channeled and pitted by the feeding of the larger larvee (Pl. III). The life of such vines during this infestation has been sustained by the throwing out of new fibrous roots either at the crown or from thie large lateral roots at a short distance from the base of the vine. If the number of larve increases sufficiently to eat off these new fibers, the whole vine declines quite rapidly, and the effect of the attack is readily recognized by a sickly stunted growth of vine and undersized clusters of fruit, and in extreme cases by the early shedding of foliage and actual shriveling of fruit before the Tipening period. | BEETLES RELATED TO THE GRAPE ROOT-WORM BEETLE. The grape root-worm is a member of the large group of leaf-eating beetles known as the Chrysomelide. To this family belong the common Colorado potato beetle (Leptinotarsa decemlineata Say), the elm leaf-beetle (Galerucella lu- teola Miill.), the asparagus beetle (Crioceris asparagi L.), several important pests of the genus Diabrotica, the grapevine flea- beetle (Haltica chalybea Il.), and many other injurious beetles. Closely related to Fidia witi- cida Walsh (fig. 10) is the Cali- fornia grape root-worm (Adozus obscurus Li.) (fig. 2), of which there are two varieties, namely, a black form, known as A. obscu- rus, and a bicolored form, known as A. obscurus vitis. Both vari- pues occur in this country and Fic. 2.—The California grape root-worm (Adoxus have been reported from sev- obscurus): Adult or beetle. Much enlarged. eral widely separated States and ‘0"#"""!” from Canada. It is found generally in Europe and throughout Siberia. At present it is becoming injurious to vineyards in Cali- fornia, infesting the European varieties of the cultivated grape. A valuable contribution to the knowledge of this insect was published by Mr. H. J. Quayle* in 1908. In habits this beetle is in most respects similar to the eastern grape root-worm, Fidia viticida, and the two pests can thus be combated with similar methods. It will, however, be necessary to take into consideration the local conditions it, a oR WW @ Bul. 195, Cal. Agr. Exp. Sta., 1908, 16 7 THE GRAPE ROOT-WORM. and variations as to the habits of the beetles in order to accomplish effective results. There are at present 6 species of the genus Fidia known to Boreal aN peta ACNE VE: Ha Ba ~, Noo SSD SSS LSS SSS — A . y Fic. 3.—The grapevine Fidia (Fidia longipes): Adult or beetle. Much enlarged. (Original.) America and. by including # those occurring in Central — America there are 14 known species. Of these, Fidia viti- cida Walsh and Fidia lon- gupes Melsh. have been re- corded as being injurious to the native varieties of the domesticated grape. Fidia longipes (fig. 3) is found gen- erally throughout the Mis- sissipp1 Valley and in the Eastern States. It is, how- ever, less common than F. viticida. In Missouri and Kentucky it occurred in in- jurious numbers on the Con- cord and on Norton’s Vir- ginia varieties of grapes. The earlier stages of this beetle are not yet known. For characteristic distinction of the species of Fidia reference is made to the works of Lefevre, Jacoby, Horn, and Scheeffer, as listed in the appended bibliography (p. 93). ; BEETLES FREQUENTLY MIS- TAKEN FOR THE GRAPE ROOT-WORM BEETLE. There are several different kinds of beetles injurious to the erapevine, and these when found in numbers are frequently mis- taken for the grape root-worm beetles. It is essential that an insect pest should be properly determined before any success- ful control measure can be prop- erly recommended. Although most leaf-eating beetles can Fic. 4.—The grapevine flea-beetle (Haltica chaly- bea): Adult. Much enlarged. (Original.) be controlled with a poison spray, as used against the grape root- worm, there exists a marked difference in the time ‘of appearance of | Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE IV. Fig. 1.—Five-year-old grapevine with normally developed root-system; enlarged portion showing root fibers. (Original.) Fig. 2.—Four-year-old grapevine, showing result of feeding by larve of the grape root-worm. (Original. ) DESTRUCTION OF ROOT FIBERS BY LARVA. 4 Dail ; BEETLES MISTAKEN FOR GRAPE ROOT-WORM BEETLES. 17 the different pests, so that an application intended for one may not at all affect another. The descriptions with figures of the following beetles and of their more characteristic habits will aid the vineyardist in distinguishing the grape root-worm from other injurious species. . The grapevine flea-beetle (Haltica chalybea Ill.) (fig. 4), measuring about one-fifth of an inch in length, is readily recognized by its brilliant metallic color, which varies from steel blue to green. It is of a robust shape, with thickened thighs well adapted for jumping. With the opening of the buds of the grapevine in the spring the beetle generally makes its appearance. The larve, which are found in the early part of the summer, feed, like the adult, upon the leaves of the grape. The rose-chafer ( Macrodactylus subsm- nosus Fab.) (fig. 5) ap- pears as a rule at the time of the blossom of the grape. Itisaslen- der beetle about one- third of an inch long, with the body tapering a little toward each ex- tremity. It is covered z with a grayish-yellow 7 down, which gives rise to its color. The pale reddish legs are long, at the joint armed with prominent spines, and terminate in very long black claws. The an- tenne, or “‘feelers,”’ are . Shur and have at the Fie, 5.—The ke eh ose Adult or end a laminated club- like structure. The beetle readily attracts attention because of its activity and great abundance wherever present. It preferably feeds upon the clusters of the blossom, and to some extent upon young grape-berries and leaves. The red-headed Systena (Systena yan Fab.) (fig. 6) somewhat resembles the previously described beetle. It is, however, smaller, measuring about one-sixth of an inch in length, and is black in color except for a pale reddish area between the eyes. This beetle has of late become quite injurious to young grapevines, feeding upon the leaves to such an extent that it often kills the vines. The feeding 51282°—Bull. 89—10-——2 THE GRAPE ROOT-WORM., 18 marks of the beetles are quite characteristic, consisting of round patches eaten into the parenchyma from the upper surface of the It is a very shy little creature, and on the slightest dis- leaves. turbance jumps off and hides beneath the foliage. Young vineyards when infested should be promptly sprayed with a mixture of from 5 to 8 pounds of arsenate of lead to 100 gallons of water. This gives the plants a very good protection. The earlier stages of this insect are not known. The grapevine Colaspis (Colaspis brunnea Fab.) (fig. 7) in its gen- eral appearance resembles the grape root-worm beetle. It is, how- ever, slightly smaller, has no pubescence, and is of a pale yel- It is nearly one- \ lowish color. fifth of an inch long, with the body densely punctate. On the \ f ci XQ Va E \ A KS rt "7 mn ' ih % } a FIG. 6.—The redheaded Systena (Systena Jron- Fie. 7.—The grapevine Colaspis ( Colaspis brunnea): Much enlarged. S é “ Adult or beetle. Much enlarged. talis): Adult or beetle. (Original. ) (Original.) wing covers the deep punctures are arranged in double longitudinal rows or striz. The beetle feeds upon the grape foliage in a manner more or less similar to that of the grape root-worm beetle. It is not within the scope of this paper to treat the various insect problems, such as those of the grape leafhopper (T'yphlocyba comes Say), the grapeberry moth (Polychrosis viteana Clem.), the grape cur- culio (Craponius inequalis Say), and others, which from time to time These pests demand special treatment, confront the vineyardist. and in cases of serious infestation an entomologist should be con- sulted. It has, however, been our observation that well cultivated DESCRIPTION. 19 and properly sprayed vineyards are less subject to the attacks of insects. Such infestations are very frequently the direct outcome of neglect in the general care of vineyards, as is more fully considered elsewhere in this bulletin. DESCRIPTION. THE EGG. (Pl. I, figs. 3-4.) The eggs of the grape _ root-worm beetle are small yellowish-white objects, ‘Measuring 115 mm. im Fic. 8.—The grape root-worm (Fidia viticida). Larva: a, length and are about one- __ Side view of full-grown larva; }, front view of head; ¢, third as broad as long. In maxille and labium. Muchenlarged. (Original. ) form the egg is cylindrical, with the two ends almost hemispherical. As the shell is very flexible and the eggs are generally laid crosswise on the canes, they often assume a slightly curved shape. Through the semitransparent shell the segmentation of the embryo can be seen, and later, as the young larva attains its full development, the Fic. 9.—The grape root-worm. Fupa: a, Upper view; b, lower view; c, normal position of pupa in cell; c, d, showing the pupa supported by the spines in the cell; e, hind Part of body, showing termina] spines. Much enlarged. (Original.) head with the dark-colored mandibles becomes clearly visible. Prof. F. M. Webster observed the larva backing out from the eggshell i in the process of hatching. THE LARVA. (Pl. I, figs. 5-6; text fig. 8.) The full-grown larva varies in length from 8 to 10 mm. It is whitish, with the head, thoracic shield, and spiracles pale brown. 20 THE GRAPE ROOT-WORM. The mandibles and the margin of the clypeus and areas around the antenne are almost black. ‘I'he anterior margin of the upper lip is armed with short and stout spines (fig. 8, 6), and as the inner surface is reenforced by chitinous ridges extending inward, its function is probably that of ascraper. The sete on the head and on the cervical shield are rather prominent; those on the sides and back of the body i é are less conspicuous. The ventral parts of the abdomi- yw nal segments are armed with “strong spines, which are particularly large on the fourth to the eighth seg- ments. These project ob- liquely backward and are properly termed ambula- tory setz. The legs are slender and proportionately SSN SS > hy 0 | th i HHA YA, a i fj Sa . SR) We A SS SS > = WN Ss h iy = Wf Mi ie SS SS f i) very small. Normally the iy My larva assumes a curved posi- WS SS tion (fig.8,a). The anterior \ portion of the body can be straightened out at will, but the hinder parts remain curved, which is character- istic of the larve of most a : underground beetles. The mY newly hatched larva is little Fic. 10.—The grape root-worm: Adult or beetle. Much over 1 mm. in length and We Ge ae of slender form; the legs are relatively large, and the setz of the entire body are long and prominent. ¥ WA THE PUPA. (Pl. I, figs. 7-9; text fig. 9.) The length of the pupa is from 8 to 10 mm. When newly trans- formed it is whitish, with a slightly pinkish tinge, which in a few days after pupation disappears and the pupa becomes white. The upper part of the head and anterior margin of the thorax are armed with large spines; each anterior and posterior femur is armed with one curved hooklike spine and two straight, more slender spines. The middle femora have only hairlike bristles. The posterior end of the abdomen carries two stout, flattened hooks, curved upward, and several pairs of spines and bristles (fig. 9,c and d). The pupa in the DESCRIPTION. DL cell is supported by these larger spines and its body is not in touch with the moist walls of the cell. As these large and strongly chiti- nized spines do not occur in either the larval or the adult form of the insects, it is probable that their main function is to sup- port the pupa in the cell. IYI YI AY ANT THE ADULT OR BEETLE. (Pl. I, figs. 1-2; text figs. 10, 11.) The original description of the beetle as made by Walsh is given below: Fidia viticida, new species. ‘Chestnut rufous, punctured and densely covered with short grayish white prostrate hairs, so as to appear hoary. Head rather closely punc- tured, with a very fine longitudinal stria on the vertex. Clypeus and mandibles glabrous and black, the clypeus with a subterminal trans- verse row of punctures, armed with long golden hairs, the mandibles minutely punctured on their basal half. Palpi and antennz honey- yellow verging on rufous, the antennz , ‘ 2 as long as the body, with joint 4 Fic. 11.—The grape root-worm: Structural parts of the fully 4 longer than joint 3. Thorax adult or beetle—a, Front view of head, showing biting 1 mouth parts; 6, lower view of labium and maxille; finely and confluent y punctured, c, antenna or ‘‘feeler;’’ d, terminal portion of the about as long as wide, rather wider Ovipositor; e, Ovipositor with membranous portion behind than before, the sides in a extended; f, front leg of male beetle; g, front leg of convex circular arc of not quite 60°, female beetle; h, claws of tarsus. All parts greatly the males with the thorax rather °™*78° (Oneinal) longer and laterally less strongly curved than the females. Elytra punctato-striate, the striz subobsolete, the punctures approximate, and rather large but not deep, the interstices flat and with close-set fine shallow punctures. Legs with the anterior tibiz of the male suddenly crooked } of the way to their tip; anterior tibiz of the female as straight as the others. Length ¢ .24-.27 inch; Q .24-.28 inch. The ovipositor of the female (fig. 11, d, ¢) consists of a more or less solid terminal portion and a membranous proximal part. Ordinarily it remains completely withdrawn within the abdominal cavity, where the terminal part lies within the membrane, which is folded into three parts. Meso-ventrally the membrane is supported by a slender chi- tinous rod (fig.11,¢). In the terminal portion are a pair of chitinous rods. Fully extended, the ovipositor is three times the length of the abdomen. 22, THE GRAPE ROOT-WORM. . SEASONAL HISTORY. The grape root-worm attains its growth during the feeding period of the larve. The pupal stage, following the long larval period, is a process of transformation, whereby all the internal organs, and to some extent the external parts, become reconstructed, resulting, with the throwing off of the pupal skin, in the appearance of the beetle. It is during this latter stage and in the early part of the summer that reproduction occurs. The diagram (fig. 12) will, it is believed, greatly aid the reader in comprehending the development and the activity of the grape root- worm in its various stages throughout its life cycle. This illustra- tion has been compiled from both field and rearing observations and represents the life of a single beetle under average conditions. In the following consideration of the life history of the grape root- worm is presented the results of rearing experiments and field obser- vations for the year 1909. In most respects that year was normal as regards climatic conditions and the insect developed as might be expected under average conditions. In view of the extreme varia- tions in the development of the insect during 1907 and 1908, the records of observations for these years have been treated under the topic ‘‘Seasonal variations in the life history of the grape root- worm.” The rearing and experimental methods relating to the tables of the life-history work are described separately on pages 44-50. THE ADULT OR BEETLE. THE PROCESS AND TIME OF EMERGENCE. Prior to its emergence the beetle spends several days in the pupal cell and at the time of the shedding of the pupal skin is of a light turbid yellowish cast, and is comparatively soft and for a time help- less. On an average the beetles remain 4 days in the cell, while the parts of the body harden. In Table XV (p. 38) are given 25 observa- tions on the length of time the beetles remain in the cell after trans- formation. In one instance a beetle remained in the cell 7 days. The minimum length of time was 2 days. Dead beetles have been found in cells, both in the breeding cages and in the ground in vine- yards. This occurrence, however, has not been found sufficiently common to cause any material reduction in the number of insects. The time required by the beetle in passing through the soil to the surface varies considerably with the distance to be covered and the texture and moisture of the soil. It has been possible to make only a few observations on the process of emerging. ‘These were made in breeding cages with glass sides, in which the beetles have worked their way out to the edge of the soil next to the glass. One beetle which left the cell July 6 emerged July 9. On its way upward it had SEASONAL HISTORY. Te to dig around a flat pebble, and as a result passed through 34 inches of soil. Another beetle left the cell July 5 and emerged July 6, having penetrated the soil for a distance of 1 inch. A third beetle left the cell July 16 and emerged July 19, in which time it worked through 2 inches of soil. In the process of digging, the beetles make use of the mandibles and to some extent also of the legs. The cells become partly filled with earth by material being pushed behind and beneath the beetle. In this process the channel is refilled and only a small hole is left on the surface to indicate where the beetle emerged (PI. Fig. 12.—Diagram showing time and development of a single individual of the grape root-worm under average conditions, as observed in 1909, at North East, Pa. (Original.) I, fig. 10). In vineyards where the ground remains undisturbed such openings can be readily found during the emergence period of the beetle. In 1909 the first beetles observed in the field were collected by the senior author June 28, and, since daily observations were made of vineyard conditions, this record probably represents the earliest occurrence of the beetle for the season. In the breeding cages the 24 THE GRAPE ROOT-WORM. first beetle emerged July 1, which shows a fairly uniform emergence of beetles in captivity as compared with their emergence in the field. The results of the emergence experiments are given in Table I. TaBLE I.—Date of the emergence of 398 grape root-worm beetles (Fidia viticida) from the ground, as observed in the breeding cages in the spring and early part of the summer of 1909 at North East, Pa. Number ; Number Number Number Date. of beetles. Date. of beetles. Date of beetles. Date: of beetles. ulyleee ce al Urbble es 36. uly Lie. 8) eauly 2a 4 Ditlye2e se. Oa ulyel Ose 39 || July 18...- 4 || July 29... 1 July's... 2+ Alm dilly Mee ee 19 || July 19...- 5 |) oily: s0iees 2 July 425.5 If |) July 12.2.2 36 || July 20...-. 2 |) AugSo2e 1 Jubyvo= 22. Ton) daly Asse BB) NP Able ORAS oe 6.|) Aug. 9. 22 1 ' Jullyi62 22 27 || July 14.... 16 || Sully 23225 doll ae eee ee ee daly fo. 34 || duly 15... 26 || July 24.... Ge | eee tae =. 2 Pe Ae as S222 Tie Ae Gs === 26 || Sept. 14-22. 23 itl pees DAD Nh Ales ok 32 De PALS Ae eco 46 || Sept. 20..... 15 Popes L577 Motali ee. 2,322 Totals 5. = 1,590 Movall soe 474 Total number of eggs: 5,963. With the exception of a few early records, which were obtained from beetles collected in the field June 30, these records represent the total oviposition by the greater proportion of the beetles emerging in breeding cages (listed in Table I), and for their entire length of life. As the date of the emergence of these beetles was normal and simultaneous with the occurrence of beetles under natural conditions in the field, it is thought that this record of egg deposition may closely approximate oviposition in vineyards. In considering the relative number of eggs laid at different dates, it will be found (Table VI; fig. 15) that previous to July 22, 13.5 per cent were deposited; from July 22 to August 8, 71.4 per cent, and after August 8, 15.1 per cent. Previously it has been shown how the timeof emergence of the beetle varied, as a result of the development of the insect under different conditions. Thus oviposition in the same sections of the grape belt must differ under similar variations. The extreme of such variations has been especially marked-in vineyards 32 | THE GRAPE ROOT-WORM. located on the hill as compared with those in the valley. In Table XI is shown the time of hatching of eggs in the two named localities. On the hill the eggs were one week later in hatching, mainly as the result of later deposition. 70 4Y 8 8&2 7 7 August | Seprember Fic. 15.—Curve showing time of egg deposition and relative abundance of eggs laid in rearing cages by beetles of the grape root-worm at North East, Pa., during 1909. (Original.) LONGEVITY OF MALE AND FEMALE BEETLES. On an average the beetles have lived in captivity one month. In Table VII will be found a full account of the length of life of individual male and female beetles. _ TABLE VII.—Length of life of individual male and female beetles of the grape root-worm as recorded in breeding cages at North East, Pa., during 1909. Date. Days. | Date. Days. No.| Sex. = : No. | Sex. " = merg- : e- merg- : : e- ene” | Died. | Male. male. ee Died. Male. male. 1{ & | June 30| Aug. 4 Si | tae Ree 24.) °O || Jaky: 10°) Awes shies 32 2 Q -do. July: 722s 22 25.) “ic fo) Aug. 6 A Noose Sach Tae July 26 AA aY| ree 26 2 do...) Aug: -4geees 25 Ae Oo ce edOr es Uy on wasee o ZH Wir ee Wah -do....| Aug. 14 3535 Bhi qode 2. ¢) Daly 22 Joie) Ae 28} 2 -do.:2:) Aug. 2beeosees 47 6 Oils 502 So Ney pee = 21 29h ih do. Aug. 23 AA | 2 828 7 oe |-tedos 22) Auge 19 SE ete oe 30 Q do-:..|. Allg. 245 sees 45 8 Q IO 5 | AE igo eee 34 31 ree July 11 | Aug. 22 BD ee ees Onl et 0-22 5 |SAligas 8 BONG ee 32 2 0..-2| Sept: Soe 60 10 2 do ANI Pal Se 32 33 oS July 12| Aug. 9 yids iu ae ye ll ref do Aug. 26 LY fall Lae 34 Q 0... :|.2d0. eee 28 ia 0 do age el es Sat) Boel hat do Aug. 5") ae 13 roi do July 22 22 Se 36 Q do. :22) Avg: 255 eae 44 14} @ do Sulys 225i 23 SEU eres do: .=.| Auge 16 Pahl Re ve eae to) of July 2 | Aug. 25 72 Ml Pees 38 2 do... -_| Avg.) .20n cee 45 16 Q fe) ATE HS oe oe 38 |; 39} og |; June 15 Aug. 25 AL es eee 17| o do Becined: |) sal eeee. 40| 9 tal: dO eee 41 18} 9 do Dt eas) We eee 60 41| So | July 27| July 28 i ee 19))"° S +1 July, °3 | July +23 2Dne acs 42| 9Q -do.) | (Aug, ° 267722 30 20 fe) fe) July a2As |. Se 21 43 ee do....| Aug. 14 18, jesse 21 3 July 9| Aug. 10 AVN aoa 44 Qo 05-2 Ale 21 hee 31 22|. 2 (o) AMIE (25, 4 Sou 45 45| so | July 30| Aug. 15 Bo (ie St = 231 3 | July 10 | Aug. 27 AS eee te 46} 9 of.) Sept, 22%|p2se 54 SEASONAL HISTORY. 33 The summary of these records (Table VIII) shows that the female beetles on an average, not individually, survived the males by 4 days. Taste VIII.—Summary of the length of life of individual male and female beetles of Table VII. Sex. | Average. | Maximum.} Minimum. Days. Days. Days. Met ARE Secs sys se 2 bs SS he tb See ea ae eee eee 32.1 54 il TN BECO ved ate Ee elo Site eC a eC re ee 36. 4 60 21 The maximum length of life for the males was 54 days, while that for the females was 60 days. In Table V is given further a summary of the length of life of the beetles in the stock jars, where no separate record has been made as to life of male and female individuals. THE EGG. INCUBATION PERIOD OF THE EGG. The time necessary for the hatching of the eggs depends largely upon the prevailing temperature and probably also upon moisture conditions. Experiments to test the effective limits of these influ- ences have not been made, but the results of these factors have been in a general way well marked as is evident from the difference in the time of hatching of individual egg clusters throughout the season (see Table IX). In different sections of vineyards the hatching probably varies slightly, since some eggs are located in well shaded places, while others are so situated as to receive more heat from the sunlight. In the middle of the hatching period eggs which were kept in an open outdoor shelter hatched, on an average, in 12 days. The rate for hatching for the entire egg period is shown in Table IX. 51282°—Bull. 89—10——3 34 THE GRAPE ROOT-WORM. TaBLE [X.—/Jncubation period of eggs of the grape root-worm as observed in 1909 at North East, Pa. - No. of Date. No. of Date. obser- obser- va- Days. ||" ya. Days tion. Laid. | Hatched. tion. Laid. -| Hatched. July 15 | July 29 14 49 | Aug. 7 | Aug. 23 16 Bo OOe) 224 a Ly SU 15 50 | Aug. 8 | Aug. 20 12 July AGA dow. a, 14 Bl. |..d05;, =.) Aug. Zia 1 2 3 4 | July 18] July 31 13 62/5). 0 2 22 | Ane: 28 14 DL |aesOOeee Nea Ue. vk 14 63> [2 do-s.| (Anes 23 15 6 | July-*19 12 do. 43 54 do Aug. 24] 16 io Unnulye 20 Ssadons ssh? 55 | Aug. 9 1..-doz 15 82 |523d02 4] -Aug rT 2 13 Ab tes dO Aug. 25 16 Ox] Sully: (2a | Ones 12 5f 4) Aue. Oe sdon. 15 10 \22-do. >. 3| Aus: 3 13 58" Io. -COhsas- Aug. 26 16 Jl | July 22) Aug. 2 ll 59 do. 25") Augz 27 17 1D Al ao, Aug. 3 12 60 | Aug. 14 | Aug. 26 12 13 | July 23} Aug. 4 12 61) |S don sss | Auge 27, 13 14 | July 25 | Aug. 6 12 62. |-..do. 2 -| Aug 28 14 LS) Sy e265) doses rik 63 |...do- Aug. 29 15 IG edo. Age i 12 64 |...do- Aug. 31 17 17 at aly 27 doe ere. are 65 | Aug. 16 '|2.:do.2 15 18 | July 28 | Aug. 8 11 66. |-4-do-. Sept. 1 16 19h Dualbyge 2952 ye GO ee fae kO Of Aue Ee |. -dox 15 20 ee eGo Aug. 9 11 (ts PO CO Sept. 2 16 Ot cedars. Aug. 10 12 69 -do. Sept. 4 18 22 | July 30 | Aug. 9 10 WOME dO. 2-4} Septienss 19 B |-2-don-s.| Aug. 10 11 71 | Aug. 18} Sept. 4 17 2A Nor Oe Aug. 11 12 72 .do.; :...| Sept, 5 18 Pay sel) Aug. 12 13 73 .do. Sept. 6 19 26 | July 31 | Aug. 11 11 (Aa doe Sept. 7 20 24 |= 200). 2.2) Altes AZ 12 13 \2..d0..5_4)- Seppe 10 23 28. a Apu Al Sd Ore) dees soo ated 76 | Aug. 19 | Sept. 3 25 29 Ss. 100% Aug. 13 12 qd? |..sd0. ..:| Sept. 4 16 30 |-Aug. .2.|..-do. 11 78 -do. Sept. 6 18 Ble | Atie =B) eden 10 (9s Saor Sept. 7 19 52)... 20. Aug. 14 11 80 |...do....| Sept. 8 20 Boe: 2adox 225! Amery 12 Sle iRedo- Sept. 9 21 34 |...do....| Aug. 16 13 82 |...do.-.-| Sept. 10 22 35 | Aug. 4] Aug. 17 13 83 [Lido Sept. 11 23 36 | Aug. 5 | Aug. 16 11 84 |...do- Sept. 12 24 Si ase =dOr Aug. 17 12 85 | Aug. 20 | Sept. 6 17 38 |...do. Aug. 18 13 86.:(-22d0. Sept. 7 18 51 ae 0 C0) Aug. 19 14 of ite Neen (UR Sept. 8 19 40 | Aug. 6] Aug. 18 12 88 =|. doz Sept. 9 20 Al); _2do- Aug. 19 13 89 | Aug. 26 | Sept. 18 23 42 -do. Aug. 20 14 90) \2-2do Sept. 19 24 43 do Aug. 21 15 91 | Sept. -3-} Steriles |S2tsee= 44 | Aug. 7 | Aug. 18 11 92, | Sept. 10:| ‘Sterile! je2222=- 45 do Aug. 19 12 93° |) Sept.-127|-:Steriles |s2-2s< 46 do Aug. 20 13 94 | Sept. 13 |- Sterile. |-----.- 47 -do Aug. 21 14 95 | Sept. 14} Sterile. |.-.--.- 48 do Aug. 22 15 96 | Sept. 20 Sterile. |---:--- TaBLe X.—Summary of Table IX, time of incubation of grape root-worm eggs for 1909. Incubation. Average. | Maximum. | Minimum. Days. Days. Days. Hor: thelentire ere periods eee a. Soe ee eee aa ee 14. 67 24 10 For the maximum egg period, July 22-Aug. 8, inclusive. ..... 1253 16 10 Eggs laid at approximately the same date by the same female varied in the time of hatching to the extent of several days. The embryological development becomes particularly prolonged later in the season with the advent of colder weather. All the eggs laid dur- ing the month of September failed to hatch. The rate of hatching of eggs in the field has been recorded in Table XI. i] ee a a SEASONAL HISTORY. . 35 a XI ald observations on the hatching of eggs of the grape root-worm in the valley and on the hill in the vicinity of North East, Pa., 1909. In the valley. On the hill. Number | Percent- Number Pa of age of of age o Date. clusters | clusters Date clusters | clusters counted. | hatched. counted. | hatched. July 30 41 39 July 30... 48 10 Aug. 4 7 42 Aug. 13 -- 56 40 Aug. 12 67 70 Aug. 19... 76 60 Aug. 19 90 91 Aug. 26 _. 66 {7 Aug. 26 103 97 Sept. 2... 97 81 Sept. 2 78 100 Sept. 9_. 98 92 Sept. 16.. 87 100 THE LARVA. VITALITY OF THE NEWLY HATCHED LARVA. On hatching, the minute larva drops to the ground and makes its ‘way to the roots of the vine through cracks and crevices in the soil and by burrowing. In this struggle to reach the food supply there is probably always a high percentage that perishes, for the number of eges deposited is much larger than the number of larve found later in the ground. The power of the young larva to exist for a time without food, however, is remarkable. In the breeding of the msect a number of newly hatched larve, confined in a glass tube, were kept alive for 8 days without food or moisture. Interesting experiments showing the burrowing and traveling powers of the young grub were carried out by Dr. E. P. Felt in 1902. This gentleman found that one larva had traveled a distance of over 47 feet in 7 hours, or an average of 6 feet an hour. In another experiment he found that 14 young larve out of 40 penetrated through loose earth in a glass tube 17_ . inches long in a period of 4 days. This tube was one-half inch in diameter and bent so that 4 inches were vertical. In our breeding cages young larve were found to feed upon the humus of the soil before reaching the root fibers; therefore it is not surprising that many larve do penetrate to the roots, even under unfavorable con- ditions, and that they are found in vineyards in compact clay soil. FEEDING AND DEVELOPMENT OF THE LARVA BEFORE WINTERING. During the summer and until late fall the larve feed extensively, and on an average attain three-fourths the full size and frequently full growth before wintering. The young larva feeds mainly upon the finer roots and root fibers of the grapevine. Later it attacks the larger roots, devouring the bark in longitudinal furrows, as shown in Plate III. Sometimes the 86 THE GRAPE ROOT-WORM. feeding may even extend to the underground portion of the stem. Most of the larve are found within a distance of from 2 to 3 feet of the crown of the vine, and at a depth varying with the root system of the vines and the character of the soil. | The rate of growth of the larva varies under different conditions. The time of hatching, the abundance of food, and the ease with which food can be obtained are determining factors. As a rule the larve are found more abundantly in loose, porous soils, and especially on exposed ridges in the vineyards. (Table SLL; fies 14) TaBLe XII.—Occurrence of larvx of the grape root-worm in different soils. Summary of field diggings for 1907, 1908, and 1909, at North East, Pa. | Total | Number Number Year. | Date of digging. number | of vines Soil. of larvee [oe ie | of larvee. }examined. per vine. 1907... We t= DuUMe Si ey ee eee ae 831 66 | Gravel. . 12 Mie yo eect Nea ee oe eee a 1 7 Clayeee 0.1 190g. {May 18-June 9.....-........--- 96 14 | Gravel. . 6 UTES (ee ear oe Rees aia ae ce 2 3 3 | Clay.22. 1 [ May 24-sUMe 2ore: ae ye sae ec sees 539 88 | Silt@... 6 1909. .|/ May 19-June 25....-........--- 439 | 83 | Gravel... 5 [May PAN Aes sess See ee cil 102 37 | Loam... 3 Jitimie AS siuly MO Se ae eae weet | 20 54 | Clay.... 0.4 a Very light porous soil. From rearing and field observations we have found that the larve are less abundant and slightly retarded in their development in clay soils. Thisis natural in that the larve can not move about to obtain food in this soil so readily as in soils of looser texture. The growth of some larve is sometimes delayed to such an extent as to hinder them from transforming at the normal period in the spring. Hence these belated larve remain an additional year in the ground and transform in the spring of the second year. The causes of delay in the development and the percentage of belated larvee have been described in detail on pages 41-44. WINTERING OF THE LARVA IN AN EARTHEN CELL. As the time for bibernation approaches the grubs penetrate deeper into the ground, generally slightly below the roots of the vines. An earthen cell is made in which the larva spends the winter. It was observed in the field in the fall of 1909 that the 2-year-old larve, referred to above, were the first to hibernate. Some of these were already in the wintering cells by the middle of August, when most of the larvee of the new brood were stil! extremely small or had not yet hatched. .In Table XIII is shown the relative occurrence of larve in wintering cells in the different vineyards. The actual percentage is higher than given, because in the process of digging many cells were broken, and thus escaped being noticed. SEASONAL HISTORY. 37 TaBLE XIII.—Percentage of hibernating larvxe of the grape root-worm as found in ~ vineyards during the fall of 1909 at North East, Pa. Curtis vineyard, in || Algren vineyard, in |} Young vineyard, on the valley. the valley. the hill. Percent- Percent- Percent- Date of age of Date of age of Date of age of digging. larvee digging. larvee digging. larvee in cells. in cells. in cells. Oct b-.-- 5 Oct. 4225. 0 Oct. 127 0 Oct: 12... 20 Oct. 14... 0 Oct. 20: .- 3 Octiilge. 12 Oct. 19... 14 Oct. 28... - 16 Octs 28 2. 83 Oct, 25-2 - 36 || Nov. 12.. 33 SPRING FEEDING OF THE LARVA. In the spring, with normally developed larve, comparatively little feeding takes place. In the early part of May, 1909, the larve in the rearing cages were still in their wintering cells, and the condition in the field in most places did not permit the larvee to become active previous to that time. Since occasional pupal cells were found on May 24 in the field (Table XIV) and continued to appear in rapidly increasing numbers, the time of spring feeding may, on an average, have lasted 20 to 25 days. Taste XIV.—Appearance of larve of the grape root-worm in cells previous to pupation at North East, Pa., 1909. Percent- Pateof | Soil | number | oflarve | 28°! igging. condition. : arvee of larvee. | in cells. maleate May 19..-| Gravel....-. ABD) Wee oe EE Co eae eeee May 24.../ Sandy..... 35 3 8.6 Maye 2552525252 Gone: 140 37 2.8 IDOee | woamime es 33 i Pah 7 May 26...) Gravel....-. 32 2 6. 2 Maye aie |i Clayzacascce 47 4 8.5 May 29a SilGveces 79 23 29.1 Juste saa Clavie (ott US es ner ate || Sees Hie ae June 2S.) Gravele.. 7 2 2.8 JUMese es! MOllibe = ee 63 25 39.0 June 4...) Gravel..... 54 10 18.5 TIME AND MAKING OF THE PUPAL CELL. -The pupal cells are found from 2 to 3 inches below the surface of the ground. Like the wintering cells, they are made by a peculiar rolling and twisting motion of the larva, whereby the cavity is enlarged, the earth becomes packed together, and the inside smoothly finished. The cell is quite spacious and would readily accommodate a larva twice the size of the owner. Usually 15 days are required to complete the pupal cell. As recorded in Table XVI, the average length of time spent by the larve in the cell is 21 days, which includes the post-larval stage described below. Should the cell be disturbed 38 THE GRAPE ROOT-WORM. or destroyed some time before the post-larval period, a new one is readily made, and, as a rule, within a shorter time than was required _ for the making of the first cell. As recorded in Table XV, individual No. 21, a larva made the second cell and pupated within 9 days. TABLE XV.—Observations on the transformations and habits of the pupa and the beetle of the grapz root-worm in the soil, from breeding experiments at North East, Pa., 1909. Date. Days. Making | Pupa- Pace Left the | Making | Pupal Beetle of cell. tion. ieee cell. cell. stage. in cell. ie AE PORE, Bee 97 May —| June 17 | June 30| July 6|__........ 13 6 EE Oe atta fey a LENE OE May —|.--do..: 3), July Ol | 3¢Died) meas sO) eee © ae Me Co Oe ree AE May. —.|..:d0..2--) July 2,2 33d ae eee EGE Se ees EAS ee eh eee Ra eS ae May —| June 15| June 30] July 5:J|_.____.... 15 5 Bie Woah ety) ace a2 ai opens oe May ~—- |; June<20;| duly ei |e ee eee I (a ee 2S, | are ea eee eee re een May — Sune 197) Turkys (9a. eee | Wy ame ea F ANG etn Sea ae Cee May —| June 21 | July 10] July 14 ].__....... 19 4° 8 Sacer ee eee May 230" 222005, =|-. -donoss dort. 4| ee {Ce Ne 4 Oe ee Pe Ee gS Sate do....| June 20| July 2 (Died). 21 122 Se IU) Yee PE RN Se eas Sas May —| June 21 | July 9+ July 13.|__.:-.-.-- 18 4 ES oe eee a ee May 30 | June 24 |...do....| July 14 25 15 5 | I gear te peepee estes eM May — |. June 20:\¢s-do...-|. July. -bsn| nee ee 19 4 1 eye Ae AER ee ee EER TSC May — | June 21 | July 10 |...do....|.......... 19 3 A es ee eee eee eee May — do Gow =<3| dalys 144). 3 Ssoe 19 ! 4 Loe ha ae Sa Oe Ree ae May — do July, 29-day: Tae 18 4 Lata ies ares cae gree EN May 30] June 20 |...do....| July 16 21 19 7 i by (ae ae ea eee, aaa =2do0. 24) June 183 July. 7) Sully: 13 19 19 6 LSet St. Sees ee do June 21 | July 10 do 22 19 3 1953S eee eee do -do. July 9 do 22 18 4 DO) eens A 2c: Seemenene Sian June 7 |..-do- BO aise Se one 14 18) |\7232 ee De Soe ae ee ee ie te) -do. July 6] July 13 9 20 (4 7 PER I ee Nee a ee May 30} June 16| July 12/ July 16 25 18 4 7.2, egos Me BEM ig Ste A ahaa he Sune: +7 une 24. | oiibyestls heen 14 20):| a ee ez URES NE ee I ee June 8| June 21 | July 13] July 16 14 21 3 De jo nee eae Soe May 26| June 22 |...do- (Died) 31 Wy i ere os PAD es ee ee NS do June 26| July 11 | July i4 28 18 3 7 (Seana aLeetee A SR Mie 3 re do June 23 |...do -do.- 28 18 3 CO SER CR a ee ee ae do G0. --|5.200 BAO m= 28 18 3 Zia! VF geaains He aap hae Sieg | eee Peak June 25: |" july “12le-sdo~ ..s |e = sae i 2 | SUR pes Se eta nn Sah 2 May 30 (0) July 14] July 18 26 19 4 SLE Soe ead ae Oe ae ees do June 2) | uly y 23) 2s ee 33 pA Ugh ene ae rs = NE Re enh res do Sumner 225|spuly = 10) 5s: se esee 23 18 es cke ee 3S eaten cee weskat 2 Soins e do June 23° | Sully? 02) |o. 2252. 24 19:0 sv eee 5 Se ee err = eee tee Ne June 4] June 25] July 11 | July 17 21 16 6 SO ee ee ae ee ioe JuUne> 265 0uly, C4: 2 ses eee 18) 2s eee Oa foe eee a See ee June: 25; | couly ols | duly Wiel eee nes 20 2 Fa ae a eae ya Se ae a Jame.29) i!" Jalysn Wisissaasss oe las eee fe ee eas ae oe ein ete ah Seeder OE ee Junes2 1s July Si sas aa ee Wee ee, ae 5! hig Ree gee SI Dee hei May 3b dune lO ea Se. eee ee 10 | .3333 565 Sal ees AVE Sere UO ee ae June 5] June 23} July 11 | July 15 18 18 4 Al Wie pee th Le hy whale Trae June 8 SS ae a eee 16 | oo. eee c] 0) £2) | See Be MRR RA pag AY Le Sa et Sos I aig 1 ae | ioe Se oe 513 696 104 TaBLE XVI.—The making of the pupal cell, the pupal period, the beetle in the cell; summary of Table X V. d a os | | Average. | Maximum.| Minimum. / Days. Days. Days. The makingjof the pupal-cell: 45-240" nee eee oe ee eee . 21.4 33 9 Pupekstage: 2-535 Se ah A re eee os ee eee 17.8 21 12 Beetiowm celle 2 se oe yee co nee ee es a os ae ee 4.1 7 2 THE POST-LARVAL STAGE. During the post-larval stage the grub undergoes marked structural changes and is in this condition extremely delicate and helpless. The body is slightly shortened, and the curved grublike appearance is modi- j : SEASONAL HISTORY. : 89 fied to a more cylindrical form. To some extent the legs become shorter and remain practically motionless. The white color changes to a light pinkish tint, which is especially marked toward the extremi- ties. Should the cell be destroyed during this period the larva is incapable of making a new one, and in many instances, as has fre- quently been observed in the breeding experiment, the larva fails to - pupate. THE PUPA. THE PROCESS OF PUPATION. _ Pupation is the result of the changes brought about during the post- - larval stage. In the process of pupation the larval skin splits on the back of the thorax and on the head, and the skin is ruptured along the median line and in front along the V-shaped suture toward the mouth (fig. 8, 6). As the pupa frees itself from the larval skin it is of a rather elongated form. The appendages are short, and the skin on these parts is wrinkled in a circular manner. The light pink color is particularly marked on portions around the spines, head, prothorax, the points of the legs, and on the hind end of the body. The pupa is at this stage very restless, turning the abdomen in a circular motion, which, together with a contracting motion, brings about the expansion of the appendages and the assuming of the normal shape of the pupe. Unlike many pupz of beetles of this group, the larval skin is com- pletely freed from the pupa. Within a short time the pupa becomes whiter in color and the prominent spines turn darker as they harden. POSITION OF THE PUPA IN THE CELL. Within the cell the pupa is continually moving, often changing its position and constantly turning the abdomen in a circular manner. Normally the pupa lies on its back, and the soft body of the tender creature is kept from close contact with the moist walls of the cell by the spines on the appendages and on the back of the body (fig. 9). This function of the spines is undoubtedly of great importance in the development of the pupa, since this is the critical period of the insect, when the organs and in fact all the parts of the insect are recon- structed in the formation of the adult or beetle. The pupa is ccm- pletely helpless when removed from the cell and is incapable of making a new one, and if left on the surface of the ground or covered up with earth it almost invariably perishes. TIME OF PUPATION IN THE FIELD AND IN BREEDING CAGES. In the field during the summer of 1909 the first pupz were found June 11, while in the breeding cages the first pupa was found June 15. The time of pupation is indicated in Table XVII, showing the relative occurrence of the pupz in the field. 40 THE GRAPE ROOT-WORM. Fae ad a (| . a ; ’ 7 ’ rm, TaBLE XVII.—Time of transformation of larve and pupex of the grape root-worm in: the field, as observed in the vicinity of North East, Pa., 1909. Vineyard. J. D. Curtis’s vineyard, porous silt. G.E. Pierce’s vineyard, gravel soil. W hitman’s vineyard, clay soil. Date exam-: ined. June 12 June 21 Number of vines exam- ined. June June June June July 6 July June 23 June 25 June 30 ely ed July 10 July 17 DAA OD DD ADHD OO Number | Number a ee of larve. | of pupe. int celle: 286 32. eee ee 6 41,4)... eee 2 54 2 2 4 24 Bre are gees esl ee Pree Ais 4 101 49) ae ee 5 13) See 5 122 eee Pe i ate a a 3 eR Ie | ae OBO 2 3 24 -e ee 1 5 eee i 7h 2 1 2 2 Reh pa 1 i 1 jrcecccecee 1 5.2 eee 1 2: 1 Ie fgets i! It is possible to establish the time of pupation by knowing the time of emergence of the beetle and the length of time of the pupal stage. Judging by the late emergence of the beetles, August 9, and by the finding of beetles in cells in the field August 14, pupze must have occurred up to the end of July. Based upon these records the curve of figure 23 has been constructed. | DURATION OF THE PUPAL PERIOD. The pupal stage on an average lasts 17 days (see Tables XV and XVI). minimum 12 days. The maximum length of time observed was 21 days and the LIFE CYCLE OF THE GRAPE ROOT-WORM AS DETERMINED BY REARING. Several attempts were made to rear this insect from eggs, and to carry it through the different stages to complete the life cycle. In the course of these experiments many failures occurred. The mor- tality in certain experiments was high; in other instances a large per- centage became materially delayed in development and the larve wintered a second season, and only a small number completed the life cycle within one year. (See Table XX.) The records from these latter observations are given in Table XVIII, with dates of hatching in 1908 and the dates of reaching maturity the following year. ——— SEASONAL HISTORY. Al TaBLE XVIII.—Complete life cycle of 19 grape root-worms at North East, Pa., reared from eggs laid during 1908; adults emerged in 1909. Date of Number Ee of days end’. Hatch- Emer- fon the : ing of | genceo ife viduals. | ‘ages, | beetles, | cycle. 1908. 1909. 1} July 16| July 9 358 1 |...do.....| July 10 359 1 esdo .| July 13 362 MWS ACOSS se) chub 10s 364 eC ood] dedlye IY 366 4) July 20} July 7 352 WSC co sid fs) 353 Aedes 22 wanaliya LO 355 BN a OO. se aif Uilhy il 356 ID | Re2dos eee ulyars0 375 1} July 25] July 26 366 1 |...do -| July 27 367 VO aisha eine Fes or bapeleaees 6, 810 SUMMARY. Days INVIETAD OM eile cs = eee oes 358. 4 Wik p chia VoN aes Makes Syne oes epee 375 MTOM, eee eee eee ae 352 SEASONAL VARIATIONS IN THE LIFE HISTORY OF THE GRAPE ROOT-WORM. In comparing the records for the time of emergence of the beetle for the three consecutive years of 1907, 1908, and 1909 a marked difference in the date of emergence will be found (fig. 16). This varia- - tion is partly due to the relative lateness of the spring and partly to the climatic conditions prevailing during the entire development of the insect in the ground. The climatic conditions for the years 1906 to 1909, inclusive, have been strikingly varied and, as will be seen, the life of the insect for these years has been affected accordingly. The mean temperature | for 1906 was 1 degree above normal and the precipitation averaged about 1 inch below normal, August and September being particu- larly dry and hot. Frost occurred June 11 and 12 and snow on October 10, 11, and 12. The year 1907 was marked with an abnor- mally low temperature, a late spring, and an early fall, with a rather high precipitation for the summer months. The month of May was the coldest on record during a period of eighteen years. In 1908, on the contrary, the mean temperature was above normal and the summer was marked by two periods of severe drought, the dry condi- tions being especially felt during the end of August. In most respects 1909 (fig. 17) was nearer the average. Although 1906 was a favorable season, during which the larve attained a normal growth, yet owing to the late and cold spring of 1907 the emergence of the insect was very materially delayed and 49 _ THE GRAPE ROOT-WORM. limited to a very short period (see fig. 16). The first beetle in the field was observed July 11. In the spring of 1908, on collecting larve in different vineyards two distinct sizes were found, as possibly due to climatic conditions of previous seasons. The larger larve were full grown, while the smaller varied from one-third to three- fourths grown. In the rearing cages the full grown larve trans- formed normally and without further feeding. Of the smaller larve few matured at the normal time, many were quite belated, while quite a number wintered, thus spending two years as larve in the ground. As a result of the early season of 1908 the beetles commenced to emerge by June 16. The emergence extended over a long period; TTT Ts p pri Da . aa aa vil ih a Fic. 16.—Diagram showing variation in time of emergence of beetles of the grape root-worm during 1907, 1908, and 1909 at North East, Pa. (Original.) the latest beetles to emerge appeared in the rearing cages July 28. This longer emergence period was partly due to the delay in the development of larve that hatched in 1907. In the spring of 1909 the larve were again of a more uniform size as a result of the long season of 1908, and the emergence in 1909, as recorded in figure 16, was — about normal. On examining larve in the field in the early fall of 1909 data were obtained as to the prevailing number of 1-year and 2-year old larve (Table XIX). At the dates of these observations only a few of the new-brood larve had attained one-half their growth while many of the eggs had not yet hatched, and since the 1908 brood larve were full grown the two broods could then be readily told apart. SEASONAL HISTORY. 43 ace iis! Se StH Ritts tate Sri ceved ese ed atataseeaazeee oe : ae ee neenieerceee .. Pe RH aun i cig gee +H mettre =a8 iesseoeais ae = as =. ssrieaait Sees wt HH ie Pe — =e ieascegeun Pe eee cra eee tae satiate a Hriersta Siete: ag sutesifestiesces Kine ate sseeupee + S Bousageaaae Ne eee ae ae ro HA =e Se — an supeess=s conn ———— gaeee Seseriecri [ i os a ale FEE cut! Sosassssascussierers ress sussbessstssssts Hie paage HH H rH aassaer ueGeaenec fe ie agua ts BES GSkeTaa8' nansae serss is SER ESE Seas Ges @ A Se Senge SSSeRSRESGREEES —— aon: sanseen ea decsuctecs Eee HH Pee is sane ee! AH iiiaste See : ee HH siiiietieit praises as beeese SSEaESsce aH =a BaS: aoe aeeees ret cians saean SEE ttt Stareeseee Peete te eee SEE gE eet eee ED SERRE cre See iat entirtit Seco cteeeee ee See ge oo Saat fees ice oa ee re SSS eae att sya ne pean nes aueee era eau er tresanies tsatnatee > id L Se va seas ett setae peers ee a eet aera tea “Bq “SBI UMON 3B G06T JO polsod Surpoorq ox} SuLINp oinyeIedUIE] WNUTUIU puB WINUITXBUI oY) JO sp1000I ATIVp OY} SurmoOys saarno oinyerodmey—7T ‘ong He f. SS ieee ae acu a Se cesconeecs gauze cra amen ace eee ee Het (‘18urs10) FH rege ) 44 THE GRAPE ROOT-WORM. TaBLe XIX.—Percentage of 2-year-old larve of the grape root-worm as recorded in vineyards in the vicinity of North East, Pa., in the fall of 1909. Vineyard in silt soil in the valley. Vineyard on loamy soil in the || Vineyard on eee loam on valley. colar Total | Per- aie “Total | Per- tral Total! Per- Date of : num- |centage|; Date of | num- |centage|| Date of ‘num- |centage vines | bar of | of old digging. vines | ber of | of old digging. vines | per of | of old digging. exam- larve.| larve. exam- aane larvee.| larvee. cae Jarvee. larve. Aug. 17 to 32 328 Oct. 12 Sept. 20 The percentages of twice-wintering larve in Table XIX represent only records of early observations when a number of larve had not yet been hatched. It is of interest to note that the percentage of 2-year-old larve was largest in vineyards located on the hill, owing to the prevailing shorter season on the hill as compared with the season in the valley. The time of transformation of the insects in other stages has similarly been affected by the climatic conditions of the past three years. In Table XX is shown the relative number of maturing insects and twice-wintering larve which were reared from eggs desaciad at known dates in 1908. TABLE XX.—The relative occurrence of transforming and twice-wintering larvex of the grape root-worm reared from eggs laid in cages in 1908, at North East, Pa. a Number of Date of hatching Benoa larvee win- 1908. 198. ©” | tering, 1909. | JatlyatG=5 ste se 5 12 Ditily<20 eee 12 0 Jilyg2ol Sete ee ee Ds 0 Dh ye2S ese ee 0 3 Total seas 19 15 In the rearing experiments other factors beside climatic conditions have influenced the results and no direct conclusion should be drawn from these observations beyond the point of establishing the fact that under unfavorable conditions individual! insects of this species do remain two years in the ground before maturing. REARING AND EXPERIMENTAL METHODS. The underground habits of the larve of the grape root-worm have made the rearing of this insect comparatively difficult, and certain obstacles have been overcome only by persistent and continued experimenting. The rearing work in most cases has been planned SEASONAL HISTORY. AD5 Fie. 18.—Portion of the outdoor rearing shelter used in the rearing of insects at North East, Pa., during 1909. (Original.) Fig. 19.—Wooden-frame box with glass bottom and wire-screen cover used in studying the pupal stage of the grape root-worm beetle. (Original. ) 46 THE GRAPE ROOT-WORM. on a large scale, so that variations would be minimized and the final averages would represent approximately normal conditions. The numerous separate experiments have involved the handling of a large bulk of rearing material, which, together with the simulation of nor- mal conditions, has to some extent necessitated special rearing devices and methods of handling. The experiments have been con- Fic. 20.—Earthen pot with glass cylinder used in rearing the grape root-worm. (Original.) ducted either in the field or under an open breeding shelter, a portion of which is shown in figure 18. This consisted of a temporary struc- ture of light wooden framework covered with waterproof canvas. Most of the rearing material was obtained in the spring, some time previous to the transformation of the larve. During the past two years of the investigation the insects were to some extent reared | a SEASONAL HISTORY. 47 from eggs laid in the cages, and these larve, together with larve of the previous year, were carried through the winter in rearing cages. The pupal records have been obtained from experiments in medium- sized wooden boxes, having glass bottom, 9 inches long, 8 inches wide, and 5 inches high (fig. 19). Each box contained 2 to 3 inches of - earth, and in order to duplicate outside weather conditions as nearly as possible the soil in these boxes was permitted to become almost dry during dry periods and during rainy periods water was propor- tionately added. To exclude the light from below, the boxes were placed upon burlap. Previous to the emergence of the beetles a wire screen cover was placed over each box. The shallow layer of soil caused many larve to penetrate to the bottom of the cages, where they appeared next to the glass; and as the pupal cells, made -of earth packed together, were next to the glass the activity of the insect inside could be readily observed. By means of a glass and porcelain blue pencil a number was fixed next to each cell, and by using this — number a detailed rec- ord could be kept from the time the cell was Fic. 21.—Rearing cage with glass sides used in the study of : the larva of the grape root-worm beetle. (Original.) : made to the time the | adult emerged. In the study of the underground habits of the insect the device shown in figure 20 proved to be useful. The glass cylin- der in the earthen pot was about half filled with soil, and to exclude the light the lower portion of the cylinder was wrapped with black paper. Several cells were made next to the glass, and on emerging the beetles were observed in the process of making their exit through the soil. _ Cages similar to the one shown in figure 21 were convenient for the study of the habits of the larva, and they were particularly useful in experiments extending over periods of one and two years. In width 48 THE GRAPE ROOT-WORM. these cages varied from 1 to 24 inches, and were of a uniform height of 20 inches. The two larger sides consisted of plate glass with outer wooden shutters on ee side which could be removed for the exami- nation of the contents. The emergence records of Table I, as shown by curve in figure 13, are the results of about 15 separate experiments with larve transforming in large earthen pots filled with soil. Since the time of emergence of the beetles and their relative occurrence has direct bearing upon the time of application of poison sprays against this pest, special attention and care were exercised in preparing these experiments. In the early spring approximately 1,000 larve were collected in different vineyards in the vicinity of North East, Pa. In many instances soil from different localities, which varied from loose sandy soils to heavy clay, was trans- ferred with the larve to the rearing pots (fig. 22). Pro- vision for the spring feeding of the larve was made by planting young grapevines in the pots. Finally the pots were placed in the ground in the open field and were left undisturbed for the rest of the season. Before ‘| the beetles commenced to Fig. 22.—Earthen pot with wire-screen cover used in rear- appear wire sereen covers ing the grape root-worm. (Original.) were placed over each pot, so that a complete daily record could be kept of the number of beetles emerging from each separate pot. By preserving the beetles from the above-mentioned experiments, rearing material of known source and age was obtained for further experiments. The daily catch of beetles throughout the emergence period was transferred to so-called ‘‘stock jars,”’ from which insects were taken as needed for miscellaneous experiments. The “‘stock jars’ shown in the rearing shelter (fig. 18) consisted of large-sized glass jars covered with thin cloth. A layer of moist sand was placed \ } SEASONAL HISTORY. 49 in each jar, which made it easier for the insects to move about and made the conditions more natural. Grape foliage, constituting the food of the beetles, was supplied daily, and to prevent unhealthy con- ditions in the cages the old leaves were always removed. For ovi- position short pieces of grapevine cane were placed with the beetles, and as egg depositions progressed these canes were removed daily -and replaced by fresh ones. In determining the number of eggs deposited, the loose bark had to be peeled off the pieces of cane and the eggs in each cluster carefully counted. In determining the egg deposition of individual females and the length of life of male and female beetles, pairs when = in copulation in the stock jars were pangqunaian SUED os pave ae OY os ang Trg pave a oer) eer | NOV., o | THT] wes yn for al HE HE HAE py wt mo | adel Chee “rs Fic, 23.—Diagram illustrating seasonal history of the grape root-worm as observed during 1909 at North East, Pa. (Original.) isolated previous to the earliest egg deposition. The observations on the habits of these individual beetles are given in Table IT. Since the greater portion of the beetles from the emergence cages was used in obtaining the egg records, and since these insects ovi- posited undisturbed during the entire season, it is believed that the records in figure 15 represent the relative occurrence of eggs in the field. Eggs used in determining the length of time of incubation were kept in glass tumblers under the outdoor breeding shelter. In conjunction with the rearing work, field observations were con- stantly made, and in certain’ instances Elleeicus of the insect in its - different stages were regularly made in the same localities for a giyen length of time. Thus it has been possible to check the rearing obser- 51282°—Bull. 89—10——4 50 _ THE GRAPE ROOT-WORM. vations with field conditions, and whenever differences have occurred corrections in the summary (fig. 23) have been made to approximate field conditions. SUMMARY OF LIFE-HISTORY STUDIES OF THE GRAPE ROOT-WORM. The life history of the beetle (see fig. 12, p. 23) may be briefly sum- marized as follows: The grape root-worm produces only one genera- — tion a year; the larva feeds on the roots of the grapevine, and in this stage the insect is found in the ground for the greater part of the year. In early June the full-grown larva makes an earthen cell a few inches ~ below the surface of the ground, within which it pupates about the middle of June; the pupal stage lasts generally twenty days, and the beetle or adult begins to emerge from the ground in late June or early July, while a few belated beetles continue to appear in the early part of August. On an average the beetle feeds for from 10 to 13 days on the grape foliage before ovipositing. The eggs are laid beneath the loose bark on the canes of the vines, and hatch on an average in 12 days; the young larva drops to the ground and soon finds its way to the roots of the vine; generally the larva becomes three-fourths grown and sometimes attains its full growth in the fall. Previous to win- tering 1t penetrates deeper into the ground, below the roots, and there constructs an earthen cell in which it passes the winter. The diagram (fig. 23) shows the relative occurrence and the time of transformation of the grape root-worm in its various stages. It has been prepared from field observations and rearing records of 1909 and is asummary graphically presenting the life-history studies. _ Local variations in the times of development of the different stages of the insect, as described in preceding pages, may be brought about by various factors, such as differences in the texture of the soil, rela- tive abundance of food, and altitude and exposure of vineyards. The seasonal variations, as shown by the difference in the time of emergence of beetles during 1907, 1908, and 1909, and also by the occurrence of larve that remained two winters in the soil, are the direct results of climatic influences. The insect has astrong tendency, however, to develop normally, even under adverse conditions. NATURAL ENEMIES. PREDACEOUS INSECTS. Several predaceous insects have been found feeding upon the larve of the grape root-worm. During the process of digging for larve, both in the spring and fall, various species of carabid beetles and their larvee have been found in the ground. These insects are entirely pre- daceous and probably feed upon the grubs of the grape root-worm whenever the latter come within their reach. Dr. E. P. Felt recorded NATURAL ENEMIES. 51 Staphylinus vulpinus Nordm. as probably predatory on the larve. In the spring of 1909 in one instance a “‘June-bug”’ larva (Lachnos- terna sp.) was found by the junior writer feeding upon a larva of the grape root-worm beetle. When first discovered the grape root-worm was already half devoured, and while the operation was being watched the remaining portion was completely eaten. The eggs of the grape root-worm are subject to the attacks of a number of different predaceous insects. Professor Webster observed in Ohio a small brown ant (Lasius brunneus Latr. var. alienus) and three species of mites (Tyroglyphus |Rhizoglyphus] phylloxere [Riley], Heteropus [Pediculoides] ventricosus Newport, and the third, resembling Hoplophora |Phthiracarus] arctata Riley), feeding upon the eggs. Mr. P. R. Jones, of this Bureau, in 1907, at North East, Pa., found a coccinellid larva (Hippodama convergens Guér.), and a malacoderm larva (family Telephoridz) feeding upon the eggs of the grape root- worm. The determinations of these coleopterous larve were made by Mr. E. A. Schwarz, of this Bureau. The junior author in 1909, at North East, Pa., collected a small ant, determined by Mr. Th. Per- gande, of this Bureau, as Cremastogaster lineolata Say, var.?, which carried off eggs from a cluster on a grape cane. The larve of a lace- wing fly (Chrysopa sp.) have been observed from time to time extract- ing the egg contents by means of their pointed, tubelike mandibles, which are peculiarly well fitted for the purpose. PARASITIC INSECTS. Two minute hymenopterous egg parasites, Fidicbia flavipes Ashm. and Lathromeris (Brachysticha) fidix (Ashm.), were reared from eggs of the grape root-worm in Ohio by Professor Webster. The late Professor Slingerland recorded Fidiohia flavipes in the Lake Erie section in 1900, and later, during the present investigation by the Bureau of Entomology at North East, Pa., this minute egg parasite has been constantly noticed by different members of the staff. Lathromeris fidie (Ashm.) has been only once observed at North East, Pa., as recorded on pages 56-57. The two parasites mentioned above were described by the late Dr. William H. Ashmead? in 1894 from specimens reared by Prof. F. M. Webster. The original description of Fidiobia is given herewith: Fidiobia flavipessp.n. Female, length,0.6mm. Black, polished; legsand antenne yellow; thorax without distinct furrows, smooth, with only slight indications of furrows posteriorly, but not sharply defined; wings hyaline, veinless; abdomen oblong, sessile, .the first segment wider than long, the second very large, occupying most of the remain- ing surface, the following being usually retracted with it, and thus making the abdomen appear truncated at apex. a Cinti. Soc. Nat. Hist., vol. 17, 1894, pp. 170-172, 52 THE GRAPE ROOT-WORM. LIFE HISTORY OF FIDIOBIA FLAVIPES ASHM. During the summer of 1909 the junior author had opportunity to rear [idiohia flavipes Ashm. (fig. 24) and to make some observations relative to its habits and occurrence in the Lake Erie grape belt. The parasitized root-worm eggs can be readily recognized in that they assume a brownish-yellow cast and become gradually darker with the development of the parasite. The grape root-worm eggs when first deposited are whitish, but soon take on a yellowish cast. In view of the semitransparent eggshell it is possible to observe the development of the different stages. Parasitized eggs were: obtained in the vineyards July 13, from which adults issued on August 3. These adults were then placed in a vial August 4, with fresh eggs which had been laid in breeding cages the previous day. On August 7 an irregular area could be distinguished in the center of each egg, indicating a breaking up of the yolk tissue. On August 11 the parasitized eggs were already cf a dark yellowish- brown cast. In one extremity of Fic. 24.—Fidiobia flavipes, an egg-parasite of me S88 inere beam te ese the i Eteach Adult ea enlarged empty space and the larva could antenna. Very greatly enlarged. (Orig- be distinguished feeding toward the aes opposite end. On August 14 most of the parasite larve pupated. Two or three days after pupation the eyes could be distinguished in the form of black spots, and a few days previous to the time of the emergence of the adults the entire pupa assumed a dark color. The minute hymenopterous flies emerged August 28, 29, and 30. In summarizing these data, we get 10 days for the egg and larval stages, 14 to 15 days for the pupal stage, or a total of 24 to 26 days for the whole life cycle. It is possible to recognize parasitized eggs 3 or 4 days after they become infested. Adult insects lived from 5 to 7 days in a test tube without food. To determine the development of parasites from 1004-emeae egos of different ages and also to test in a general way the resistance of eggs of different ages to parasitism, the Sl, experiments were carried out as summed up in Tables XXI and XXII: Fe i Paihia tgs ane a ee ee a a re NATURAL ENEMIES. 53 _ TABLE XXI.—Parasitism of grape root-worm eggs by Fidiobia flavipes at North East, : Pa., 1909, the eggs ranging in age from 1 to 9 days. Grape root-worm eggs. COS ee ee Parasit- vation. Hatched. x Oviposi- | Normally tion. | hatching. 1| July 30) Aug. 11 SRR Sete om ie a2| July 31} Aug. 12 |. x x Sra ee, ele ATI es 1S ee Us ss x e Ap PAGS HES ANI. WAS = SSS. x On PAs Aap Atel (eis. es ss. x Gp Ate s Onl GOne alse eek 3 << Zl PATE. 20) | PANIES QI er eee ee és Sale Ange al Ado Qa She ee x Or Ate 58) | Aue 20: Ne eet ae x a Parasites placed with the host August 9. New parasites emerged September 10 to 12. Thirty-two to thirty-four days to complete the life cycle. Experiment No. 2 consisted of 15 root-worm eggs, of which 13 became parasitized and 2 eggs developed root-worms normally. Eggs within two to three days of hatching escaped parasitism. ’ TasLe XXII.—Parasitism of eggs of the grape root-worm by Fidiobia flavipes, at North . East, Pa., 1909, eggs varying in age from fresh to 10 days old. ¥ Root-worm eggs. Num- Emerg- | Hatch- ber of ee ing root-| ing of obser- aie del, worm para- vation. E upee ee e88s- larve. sites. fe dle 2a | eAue: 6 15 Bee 4 bee 2| July 26| Aug. 7 20 PAD) a ee ey 3 | July 28} Aug. 8 Sola pronseseomes 37 4| July 30] Aug. 10 1G eee es oe 12 5 | Aug. 1] Aug. 11 1 bee eae 18 6 | Aug. 2] Aug. 13 IQR Ber Bee 19 7 | Aug. 4] Aug. 14 HA iso eet ate 21 Parasites placed with host August 4, having emerged August 3. New adults emerged August 30 to September 3. Twenty-seven to thirty- -one days to complete the life cycle. Root-worm eggs within two to three days of hatching escaped parasitism. For each experiment egg clusters of the grape root-worm, each of a given age, ranging from 1 to 10 days, were subjected to the para- sites. The insects with the host were confined in large-size glass vials, which were covered with fine cloth. In Table XXTitis probable that the parasites oviposited shortly after being confined with the host, since they had emerged a few days previous to their confinement with fresh eggs. In the first experiment (Table X XI) the parasites were confined three days with the hosts. The two experiments of Tables X XI and XXII are practically identical, the second being made to check the results with those of the first one. The records for the normal hatching of the eggs are from another set of records, since such data could not be obtained from parasitized eggs. The results of either experiment show that the parasites did not affect eggs which were within two or perhaps three days of hatching. There was no marked difference in the time of the development of the parasites from eggs of different ages. 54 | THE GRAPE ROOT-WORM. The percentage of parasitized eggs in the field varied considerably in different sections of the grape belt, as well as in parts of the same vineyard. It was always highest where eggs were most numerous. This was especially brought out in the different sections in the experi- mental vineyards, where the sprayed areas were but slightly infested with root-worms. : Thus, Davidson’s vineyard, consisting of 12 acres, located half a mile north of the city, showed in 1908 the following results: Average number of Per cent eggs per parasitized. vine. Unsprayed young Concord vines.......-.--.---- 18 268. 8 Sprayed young Concord: vines=. . . 422. /220-2 9.5 12.4 Unsprayed: old-Coneord vaness<2 92222 13. 2 319. 2 Sprayed, old- Concord wimnes-03 2 22%.c a MRA Nsrere eres — a ad esas oe DEN 4ce = JH-S- IE id DD 2.0 - 69 - : REMEDIAL MEASURES. he TABLE XXVII.—E fect of poison spray against the grape root-worm as shown by occur- rence of larvx at roots of vines in sprayed and unsprayed plats in Davidson vineyard an 1907, 1908, and 1909, at North East, Pa. DIGGINGS MADE IN SUMMER OF 1907. Number of larve. rere Number | Variety and age of Date of examination. Remes! anes Un- sprayed pEBYS lat plat. Beat. September 5, 1907 ...----:----- 1 | Young Concord... 92 6 D0) je. See eS cae ie ae 1 | Old Concord.....-. 91 1 WOR en ee ae cee nie 1 | Young Niagara.... 6 0 DIGGINGS MADE IN SUMMER OF 1908. . PPAMeUST 26, 19086. <=. --.5-2 52505 10 | Young Concord... 214 40 August 25, GOS ee Ses sie oo Ree 5, | (Old: Concord 3:2 - 86 4 JDXO)2 25 Sea RANG sete Pie ta 5 | Young Niagara 58 5 DIGGINGS MADE IN SUMMER OF 1909. | September 8-9, 1909..........- 5 | Young Concord... 39 0 September 10-15, 1909-.....---.- 5 | Old Concord... .--2 13 0 September 11-15, 1909-.......- 5 | Young Niagara.... 17 0 TaBLE XXVIII.—Davidson vineyard. Effect of spray applications on the crop yela for the seasons 1908 and 1909 at North East, Pa. FOR SEASON OF 1908. : Spray Variety and age of Plat Plat |Value per| Value per Year vines. Treatment. area. yield. basket. acre. benefit per acre. ; Acre. |Lb.baskets| Cents. 1908 | Young Concord..... Sprayed... ..- 4 101.8 13 $26. 26 $5. 20 LOGOS | 2 - GO oe Unsprayed.... 4 81.8 13 PANSUGF |e mee ae be 1908 | Old Concord........ Sprayed....... 3 502. 0 13 86. 97 8. 06 1908 }..... GOe se a Fees Unsprayed.... 3 455. 0 13 Piso eM hase tes raaee lee 1908 | Young Niagara..... Sprayed....... 4 231. 4 9 62. 37 21. 87 1908) |.2=: CO Oye Sispot eeea tt Unsprayed...- 4 150. 4 9 AQ 50! |b eier ee FOR SEASON OF 1909. 1909 | Young Concord..... Sprayed....... 3 435. 8 11 $95.70 | $47.96 1909 |....- CO sree Un ay tae Unsprayed.... 5 217.0 ile: AT esTA: | asta ae 1909 | Old Concord........ Sprayed......- 31 1,039.0 il 152530 39. 70 1909 |....- GOP srs es Unsprayed.... 3 836. 0 if IDE GSp Cees 1909 | Young Niagara..... Sprayed....... 4 158. 2 28 USP Ue 61. 32 1909 |..... C0 Kaji hemes greet Unsprayed.... 4 85.0 28 Plane: Xo Pte eat ok The effect of the spray on egg deposition was obtained by stripping all of the loose bark from 25 consecutive vines in the sprayed portion and also in the check rows, making an actual count of the number of ege clusters deposited on an equal number of consecutive vines in the sprayed and unsprayed plats. This has proved to be one of the best ways to determine the immediate direct effect of spray applications. These examinations were made at a time, determined by careful 74 THE GRAPE ROOT-WORM. observation, wnen the maximum number of eggs had been deposited, and before but few larve had hatched from the earliest deposited eggs. All of the bark was carefully stripped from the vine and a count made of the egg clusters found. The number of eggs in these clusters may vary from 3 or 4 to 75 or even 100. Since it was impossible to make an actual count of the individual eggs, the clusters were classi- fied, as the count was made during the examination of the vines, as. large when they contained approximately 50 eggs or more, medium when they contained about 30 eggs, and small when they contained about 10 eggs. In this manner we obtained the estimated number of eggs per vine given in the Table X XVI dealing with egg deposition. — A simple enumeration of the number of egg clusters deposited per vine regardless of the number of eggs which they contained would have given but an inadequate idea of the total number of larvee which might infest the roots of these vines. The number of canes per vine is also given to indicate the size of the vine, since the limit of the area upon which the beetles could deposit eggs would have some influence on the number of clusters deposited. The prevalence of larve at the roots of vines in sprayed and unsprayed plats was determined by making careful diggings at the roots of a given number of vines in both the sprayed and the unsprayed plats (Table X XVII). During these diggings the differ- ence in the number of root fibers thrown out by vines in the sprayed and unsprayed plats was very noticeable. On May 13, 1908, after the vineyard had received the protection of one season’s treatment with poison spray the root systems of several vines were examined in the block of young Concords. It was found that the roots of many of the vines in the unsprayed plat were almost entirely devoid of new root fibers, and that the large roots were badly channeled and pitted by the feeding of the larve of the grape root-worm, whereas the roots of vines examined in the sprayed portion of this vineyard showed that they had thrown out large masses of new fibrous roots during the growing season as a result of the protection the spraying had afforded them in the prevention of the deposition of eggs by the beetles. Plate IV, figure 1, will illustrate this luxuriant growth of new root fibers on roots of sprayed treated vines, practically all of which were produced during the growing season of 1907, as compared with the lack of them on the unsprayed vines (PI. IV, fig. 2). These illustrations also indicate the recuperative power of badly injured grape vines when protection from the larve is afforded; for in the spring of 1907, previous to the protection of the vines by the poison spray, the roots of the vines in the sprayed plat were as devoid of root fibers as were those in the unsprayed plat, as was shown by dig- gings made in the spring of 1907. Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE VII. Fig. 1.—Retarded growth of vines in the unsprayed plat. (Original.) Fig. 2.—Vigorous growth of vines in the sprayed plat. (Original.) VIEWS OF EXPERIMENTAL PLATS IN MR. ROSCOE DAVIDSON'S VINEYARD AT NORTH EAST, PA. REMEDIAL MEASURES. 715 In addition to the above-described methods of comparing the effect of the treatment of this vineyard with a poison spray, an accurate count of the number of baskets of grapes picked from equal areas in the sprayed and unsprayed plats was made and their cash value for each season recorded. This data, covering the seasons 1907, 1908, and 1909, is presented in Table XXVIII. Plate VII, figure 1, shows the light growth of the vines in the unsprayed plat as compared with Plate VII, figure 2, showing the heavy growth in the sprayed plat after three years’ treatment. RESULTS OF VINEYARD RENOVATION EXPERIMENTS. At the time this investigation was commenced the feeling was quite common among vineyardists of North Hast, Pa., that it would be useless to attempt to restore to their former productivity some of the vineyards very badly injured by the root-worm, and that it would be cheaper to tear out these old vines and replant the ground to new vines. In view of the fact that our survey had shown that many young vineyards just coming into bearing were also declining very rapidly under attacks of the pest, and that a run-down condition of old vines was very common throughout the entire grape belt, it was deemed desirable to investigate as to what could be done in the way of renovating a badly run-down vineyard. RENOVATION EXPERIMENT ON AN OLD VINEYARD. During the fall of 1906 our attention had been called to the condi- tion of 10 acres of old vineyard which in previous years had possessed the reputation of being very productive but had suddenly shown a rapid decrease in yield and also in growth of vine. The yield of this vineyard, which in 1905 was 6,597.5 pounds of fruit per acre, declined in 1906 to 1,697 pounds per acre, showing a decrease of 4,900.5 pounds and barely covering operating expenses. When visited by us in the fall of 1906 the foliage of these vines was found to be riddled by the beetles of the grape root-worm, the cane growth was stunted, and many vines simply threw out tufts of puny shoots near the lower wire of the trellis. The roots were almost devoid of fibers and badly scarred by the feeding of grape root-worm larve, and the fruit hung in scraggy clusters of undersized berries—in short, this vineyard had all the appearance of being in the last stages of production as a result of grape root-worm injury. In the spring of 1907 it was decided to undertake an experiment in this vineyard to determine if by ridding the vines of this pest, the vineyard could be restored to its former condition of profitable production. At this point it should be stated that the vineyard had received in previous years only indifferent cultivation and practically no fertilizing or spraying. The importance 76 THE GRAPE ROOT-WORM. of these operations was recognized at the outset of the experiment and arrangements were made to give the vines thorough cultivation and liberal fertilizing in addition to thorough spraying with a poison and a fungicide; in fact, to treat the vineyard according to the most approved methods of vineyard management. That spring when the vineyard was pruned many of the hiaalhe weakened vines were cut back to the ground and others to the lower wire of the trellis. Even on the most vigorous vines, not more than one to three fruit-bearing canes were left, it being thought desirable to concentrate the remaining energies of the weakened vines and force the vegetative growth rather than attempt to produce fruit of an inferior quality such as was borne by the vines during the season of 1906. In order that some light might be thrown on the effect of different kinds and amounts of fertilizer used in restoring these injured vines it was decided to divide the vineyard into seven plats of one acre each and the following kinds and amounts of fertilizer were applied: Plat I. Barnyard manure, 7 wagon loads. Plat II. Complete high grade commercial fertilizer, 1,000 pounds. Plat I1I. Complete high grade commercial fertilizer, 1,000 pounds plus 100 dane sodium nitrate. Plat IV. Sodium nitrate, 400 pounds. Plat V. High grade commercial fertilizer, 1,000 pounds. Plat VI. High grade commercial fertilizer, 500 pounds. Plat VII. No fertilizer; no spraying. ~The brand of fertilizer used in 1907-8 analyzed available phos- phoric acid, 11.28 per cent; potash, 5.89 per cent; nitrogen, 3.41 per cent. In 1909 a brand of fertilizer was used analyzing phos- phoric acid, 8 per cent; potash, 8 per cent; nitrogen, 5 per cent. The plats commenced on the west side of the vineyard and ran east- ward. Plats I, V, VI, and VII included seven rows measuring approximately one acre in area. Plats II, III, and IV contained 14 rows each, but all the data here given are reduced to a 7-row or 1-acre basis for convenience in comparison. The ground on which this vineyard is planted is quite level and is of a stony loam on the west side grading to an almost stoneless clay on the east side where it has been somewhat enriched by wash from a slight elevation lying immediately south, which doubtless is responsible for the greater productivity of plats 5, 6, and 7, at the beginning of the experiment. The barnyard manure was spread broadcast over the rows of Plat I during the month of April. The commercial fertilizer was dis- tributed on the other plats in two equal applications, the first being made May 21, when active growth of the vines commenced. The second application was made June 18, about one month later. _ All of the fertilizer was applied with a broadcast fertilizer dis- tributor and immediately followed by a spring-tooth cultivator. : REMEDIAL MEASURES. vir The ground was plowed early in May and received three thorough cultivations during the summer. It should be observed at this point that this is by no means an attempt to solve the problem of vineyard fertilization, which belongs to the province of the horticul- turist, and that the results obtained on these plats are presented without comment upon this feature of the experiment, leaving the reader to draw his own conclusions. With the appearance of the first beetles all of the plats except the check plat received a thorough spraying with Bordeaux mixture and arsenate of lead, using the following formula: Copper sulphate, 4 pounds; quicklime, 4 pounds; arsenate of lead, 3 pounds. A second spraying with the same ingredients was made ten days to two weeks later. (See exact dates on Table XXIX, showing egg deposition.) TABLE XXIX.—Effect of poison spray against the grape root-worm as shown by relative - occurrence of eggs on sprayed and unsprayed plats of the Porter vineyard during 1907, 1908, and 1909, at North East, Pa. UNSPRAYED PLAT. r ay : Average num- Number of egg clusters found. Bes, Nugne INR per of eggs. Dateos Year When exam- phases ber ber spray Pe ined. har of of aplice, Medi- vines. | canes. Re: Per : Large a Small. | Total. | of eggs. wines "caries 1907. .| Aug. 12, 1907 97 150 238 485 | 11,730 25 GG" | AGO a NS 4e Sie | seme as oe 1908. .| July 22,1908 45 91 78 214 | 5,760 25 GON 20074 le TSeO Ne ose 1909. .| July 21,1909 37 56 94 187 | 4,470 25 S| Anse 2Oh Os) les eee ace SPRAYED PLAT. Formula: 4 Ibs. blue vitriol (copper sulphate), 4 Ibs. lime, 3 lbs. arsenate of lead, 50 gallons water. 1907. .| Aug. 13, 1907 1 21 34| 56.| 1,440 25 Bile oe) 258% {wus os ‘ June 24 1908. .| July 22,1908 0 10 AAW oa Ih 240 25 Eee ene an emine oe 5 1909. .| July 21,1909 3 8 Zl) cABel. A860 PRilaewity i cist 2 sie jue ie The spray applications were made with a gasoline-engine spraying outfit specially mounted for vineyard work (PI. X, fig. 2) having an arrangement of fixed nozzles, three on each side, the two lower of which throw the spray on the side of the vines as the machine passes through the rows. The. upper nozzle reaches out over the top of the row throwing the spray downward so that it covers the new growth at the top of the trellis. This downward direction of the spray to cover the new growth at the top of the trellis is highly desirable since the beetles exhibit a tendency to feed more freely on this new growth, especially after the lower leaves have been coated with a poison spray. A pressure of from 100 to 125 pounds was maintained throughout 78 THE GRAPE ROOT-WORM. the operation, using about 100 gallons of spray liquid per acre. With this spraying outfit it is possible to cover from 8 to 10 acres i vine- yard per day. METHODS OF OBTAINING AND RECORDING RESULTS. As in the preceding field experiment, the results of the spray appli- cation were determined by counting the number of egg clusters deposited on the vines by the grape root-worm beetles at a time when the maximum number of eggs were to be found upon the vines. All of the bark was removed from 25 consecutive vines in the unsprayed plat and also in the adjoining sprayed plat. The results of these examinations are given in Table X XIX for the three seasons 1907, 1908, and 1909. Table XXX indicates the effect on the larve of spraying as shown by the number of larve found at the roots of the vines by carefully removing the soil from the base of the vine for a distance of 3 or 4 feet from the trunk of the vine and to a depth of a foot or 16 inches, going several inches below the second whorl of roots. TABLE XXX.—Lffect of poison spray against the grape root-worm as shown by relative occurrence of larvx at roots of vines in sprayed and unsprayed plats of Porter vineyard, at North East, Pa., in 1907, 1908, and 1909. ! Number of larve. Number | Variety and age of vines. Date of examination. py Rares Un- sprayed pete plat. Pier Apriland: Mayo 22 =e 40 ces Concord... 16) “| See ) Mi September 25; 1907. - 2232-2 =a. Dr Fhe 3h Ope ae see MN eos oe 2 May 27-28, 1908: 24225: eee eke LO) a sas GOR wees) sent ie 100 21 PuTde OA Oe ee See se Sees eee GOL See dns ee 67 September 2 AGOOE Bas ee oe oes ee see Gon vaa ee eae 115 19 When the crop was ready to harvest, the final effect of the season’s treatment was obtained for each plat. Table XX XI indicates the plat number, area, fertilizer applied, number of crates or baskets of © grapes, net weight of fruit, value per pound or basket, cash value per acre, cost of spraying and fertilizing, and value of crop less cost of treatment. The data in Table XX XI, giving the results of the treatment from 1907 to 1909, inclusive, show a great increase in crop yield of this vineyard as a result of thorough spraying and heavy fertilization. This experiment proves conclusively that if energetic measures are taken with vineyards rendered practically unprofitable as a result of grape root-worm injury they may be made to yield very profitable crops. REMEDIAL MEASURES. | 79 TABLE XXXI.—Crop yield of plats in renovation experiments for 1907, 1908, and 1909, at North East, Pa. FOR SEASON OF 1907. Value age Cost Cost eighe ee ee vale of two | of fer- Keeton ber of Sn" | of fruit | Value | spray- | tilizer | .*©5S Plat | pat Seat foctiieok used 8-pound| ae offruit|ingap-| and | Costof ee area. _ Kin ; baskets|_ unds|SPound| per | plica- | appli- pede : per |P basket | acre. | tions | cation |!28 20 acre Per |for 1907 fertiliz- . acre. 4 per ae ing per 1908, acre. acre. 1909. acre. Acre. Cents. i 1 | Barnyard manure...........- 129 968 123) $16.11 | $4.00 | $22.00 | —$9. 89 II 1 Sp ag fertilizer, 1,000 198 | 1,485 123) 24.75 4.00 | 18.50 2.25 pounds. iil 1 | Commercial fertilizer, 1,000 211 1, 590 123| 26.37 4.00 | 21.00 1.37 pounds; sodium nitrate, 100 pounds. IV. 1 | Sodium nitrate, 400 pounds... 194 | 1,460 123) 24.25 4.00 | 10.50 9.75 Vv 1 eee fertilizer, 1,000 308 | 2,310 123| 38.50 4.00 | 18.50 16. 00 pounds. VI 1 | Commercial fertilizer, 500 Zap) LOL 124] 31.87 4.00 9. 50 18. 37 pounds. VII 1 | No fertilizer; no spraying. ---- 263 | 1,975 1 ony tel inl Saas eclSsecaces - 32. 87 FOR SEASON OF 1908. Acre. Cents. I 1 | Barnyard manure...........- 427 | 2,606 123) $53.37 | $4.00 | $22.00 | $27.37 II 1 pa fertilizer, 1,000 482 | 2,921 124} 60.25 4.00 | 18.50 37.75 pounds. iil 1 | Commercial fertilizer, 1,000 590 | 3,542 124| 73.75 4.00 } 21.00 48.75 pounds; sodium nitrate, 100 pounds. IV 1 | Sodium nitrate, 400 pounds... 649 | 3,912 123; 81.12 4.00 | 10.50 66. 62 V 1 epaemerolal fertilizer, 1,000 681 | 4,153 123} 85.12 4.00 | 18.50 62. 62 pounds. VI 1 ee etele fertilizer, 500 630 | 4,022 12%| 78.75 4.00 9. 50 65. 25 pounds. ; Vil 1 | No fertilizer; no spraying.. -.- 535 | 3,369 IDE SOG87 Iaectstacalh teases 66. 86 FOR SEASON OF 1909. Acre. Cents. i Barnyard manure...........- 1,188 | 9,049 123/$148. 50 | $4.00 | $22.00 | $122. 50 It 1 eerie fertilizer, 1,000} 1,282] 9,898 123} 160. 26 4.00 | 18.50] 137.76 pounds. Til 1 | Commercial fertilizer, 1,000 | 1,184 | 9,146 124} 148.00 4.00 | 21.00} 123.00 pounds; sodium nitrate, 100 pounds. IV 1 | Sodium nitrate, 400 pounds...| 1,037 | 8,372 124] 129. 62 4.00} 10.50} 115.12 V 1 eeenerclat fertilizer, 1,000} 1,171 | 9,090 124] 146. 37 4.00 | 18.50} 123.87 pounds. VI 1 rane fertilizer, 500} 1,260] 9,580 123) 157. 50 4.00 9.50 | 144.00 pounds. . VII 1 | No fertilizer; no spraying-..... 855 | 6,412 IZE LOG Siete. Sasa eso eas 106. 87 80 THE GRAPE ROOT-WORM. In examining the yields for the various plats it will be observed that in the first year of the experiment plats I, IT, III, and IV fell con- siderably below the unsprayed and unfertilized plat. This condition is due in a great measure to the fact that vines in plats V, VI, and VII _ were in a somewhat more thrifty condition at the outset of the experi- ment. The soil in these plats grades to a clay loam and has been enriched somewhat by the wash from an elevation immediately south of them. While the untreated plat shows great improvement in yield simply as a result of thorough cultivation, yet the annual increase in yield on this plat was much less than that upon the treated plats in the same soil. & In addition to this increase in crop yield there was noted a great improvement in the quality of the fruit both in size of berries and of clusters. Plate IX, figure 2, gives a comparison of the size and com- pactness of fruit on a vine in the sprayed portion as compared with fruit on a vine in the unsprayed portion shown in Plate IX, figure 1. It was also found that the fruit in the sprayed plats remained firm and that there was practically no loss from shelling of the berries, whereas the fruit and stems in the unsprayed plat were badly mildewed and there was a great deal of shelling of berries. This benefit is derived from the fungicidal effect of the Bordeaux mixture. This increase in crop yield has also been accompanied by a marked improve- ment in the vigor of the vines throughout this vineyard. Practically all of the vines are now in a condition to produce a full crop of fruit, and there is no reason why this vineyard should not continue to produce as profitable crops as it did previous to its infestation, pro- vided it is subjected to treatment similar to that which it has received during this investigation. Plate VIII affords a comparison of the growth fe vine at the beginning and at the end of the experiment, the upper figure show- ing the vineyard at the beginning of the experiment, and the lower figure after three years’ treatment. RENOVATION EXPERIMENT ON A YOUNG VINEYARD. About the year 1900 there was a heavy planting of new vineyards throughout the Lake Erie grape belt. Scarcely had these young vines come into bearing when the owners noticed a rapid decline ~ both in their crop yield and in vigor of vines. Close observation indicated that this decline was due largely to injury by the grape root-worm, and that the decline of these young vines was even more ~ rapid than in the case of older, well-established vines. In many vineyards it was found that young vines had been killed outright in a single season. Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE VIII. Se ee oe heme ie pk. VIEWS OF THE PORTER EXPERIMENTAL VINEYARD, SHOWING COMPARATIVE GROWTH OF THE VINES IN 1907 AT THE BEGINNING OF THE EXPERIMENT (UPPER FIGURE), AND IN 1909 AT THE END OF THE EXPERIMENT (LOWER FIGURE), NORTH EAST, Pa. (ORIGINAL. ) Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE IX. Fig. 1.—Average condition of berries in the untreated plat, North East, Pa., 1909. (Original.) Cie i a eae Fig. 2.—Average condition of berries in the treated plats, North East, Pa., 1909. (Original.) CONDITION OF FRUIT ON VINES IN PLATS OF THE PORTER EXPERIMENTAL VINEYARD. "5 af MPO: Ph PP ¥ OA whe *Eyhete > - REMEDIAL MEASURES. 81 During the summer of 1907 our attention was called to the condi- tion of a young vineyard near North East, Pa., belonging to Mr. H. E. Mosher, which for the first three years of bearing had maintained a very thrifty condition. The soil of this vineyard had been well cultivated and heavily fertilized with barnyard manure, yet in spite of this favorable treatment the crop yield in 1907 decreased to an alarming extent, amounting only to about one-eighth of the value of the yield for the previous season. | This vineyard is about 5 acres in extent. The crop value in 1904, first year bearing, was $127.51; in 1905 it was $410.77; in 1906 it was $435.72, but in 1907 it was only $55.92 _ There is every reason to believe that the grape root-worm was directly responsible for the sudden decline of these vines, for when the roots of many of the vines, which were practically dead, were examined by us they were found to be entirely devoid of fibrous roots, and the whiplike larger roots and the crowns of the vines were badly furrowed and scarred as a result of feeding by the full-grown larve (Pl. III). From one section of this vineyard, about 24 acres in area, containing 1,584 vines, 563 dead vines were removed in the spring of 1908. In addition to this, about 50 per cent of the remain- ing vines were cut back either to the ground or to the lower wire of the trellis, thus greatly limiting their fruit production for the coming season. So discouraged was the owner with the condition of this vineyard that he was at the point of pulling out all of the vines and replanting it anew. At our request, however, he permitted us to plan a renovation experiment on this section to determine if the vines could be restored to a thrifty condition and again produce profitable. crops. This experiment was commenced in the spring of 1908. The remaining vines were severely cut back, as mentioned above, and new vines planted in the place of those which had been removed. The vines were heavily fertilized with a high-grade fertilizer. In this case, owing to the limited root area, as a result of the feeding by the larvee, it was deemed desirable to sprinkle the fertilizer by hand about the base of the vines instead of scattering it broadcast over the whole area between the rows. Twelve rows received an application of 400 pounds of nitrate of soda and 24 rows received an application of high-grade commercial fertilizer at the rate of 2,000 pounds per acre. This fertilizer was distributed in two applications; the first on May 21, when active growth was well started, and the second about a month later. With the appearance of the first beetles, June 23, 1908, the vines were sprayed thoroughly with Bordeaux mixture and arsenate of | lead, using 4 pounds of copper sulphate, 4 pounds of stone lime, and 3. 51282°—Bull. 89—10——6 82 THE GRAPE ROOT-WORM. pounds of arsenate of lead to 50 gallons of water. On July 2, 1908, a — second application was made, using the same formula as for the first application. The spray was applied with a traction sprayer at a pressure of about 100 pounds, and about 100 gallons of fluid were used per acre, covering the vines quite thoroughly with a fine spray. The whole 5 acres were included in each of these two spray applications. As a result of this treatment most of the vines made quite a vigorous growth of wood, which gave a good supply of bearing canes for next season. Owing to the severity with which these vines were cut back in the spring, the cash value of the crop from the 5 acres was $31.02. The treatment given this section of vineyard in 1908 was duplicated during the summer of 1909. The same amount of fertilizer was applied, and two applications of spray were made, the first applica- tion June 29, the second July 8. As a result of the second season’s treatment the vines have taken on a healthy appearance and made a vigorous growth of new canes. The number of grape root-worm beetles has been reduced to a minimum, as shown by the small amount of feeding on the foliage and by the number of egg clusters deposited. An examination made on July 24 showed but nine egg clusters on 25 sprayed vines as against 73 egg clusters on the same number of un- sprayed vines. Diggings made in search of larve showed a similar condition. Only three larve were found about the roots of five sprayed vines as against 55 larve found about the roots of five un- treated vines. The crop value for the season of 1909 for the 5 acres was $213.92 as against $31.02 for the season of 1908. The vineyard has made sufficient growth of vines during the season to enable the owner to put up enough bearing canes to produce a full crop for 1910. The additional cost of the operations of spraying and fertilizing for the seasons of 1908 and 1909, over and above ordinary vineyard management, amounted to $135, itemized as follows: Nitrate’ol soda, '1,000-poundss: 202. 25-2 =. 2S ee ee eee $25. 00 Complete fertilizer; 2’ tons) .):..202)2...<2 4. 2.6 70. 00 Spray material and labor, $4 per acre... 22224. . 22.032 40. 00 The success of this attempt to restore this 5 acres of vineyard to its former state of productivity can not be better summarized than by presenting the following figures showing net weight of fruit and the crop value for the years 1904 to 1909, inclusive: Pounds. Value. Gh 8 gE MeO Da Sp see ren st 2 Egle SAMMI bn a oe! Seco 11, 630 $127. 51 OOS 2 2 ks eat en ee ee ee 23, 705 410. 77 POOG SZ la Ses IIe. eo ee ae aE ee 21, 130 435. 72 190s. s.2ccetn dn’ ee eee ee 3,195 55. 92 i: | none aetna temrew eer SCF i 4, 390 31. 02 1000. col at ee 19,935 213. 92 REMEDIAL MEASURES. 83 The owner of this vineyard is greatly pleased with the results obtained by the treatment described above and is satisfied that a con- tinuation of these methods will in another season restore his vine- yard to its full bearing capacity of 1905. It might be added that previous to this experiment Mr. Mosher was very skeptical regarding the possibility that this pest could work such havoc in vineyards -and also as to the value or necessity of a spray treatment. During this experiment, however, he has become a thorough convert, and is satisfied that the intelligent use of a poison spray has been the chief factor in the restoration of his vines. SPRAYS. ARSENICAL POISONS. Arsenic in some form or other is usually the active killing agent used against insects which secure their food by chewing upon the foliage or fruit of plants, and since the grape root-worm beetles belong to the category of chewing insects the direct killing agent (or stomach poison) applied to grapevines is the arsenical poison which the spray mixture contains. There are several forms of arsenicals used as insecticides. Those that have been most commonly used in the past are Paris green and arsenite of lime. Arsenite of lime is a common home-prepared insecticide made by boiling together, for about 20 minutes, 1 pound of white arsenic with 4 pounds of sal-soda crystals in 1 gallon of water. This is known as the Kedzie formula; and when used with water, milk of lime made by slaking 2 or 3 pounds of good stone lime must always be added to 50 gallons of the mixture; for the boiling of the sal-soda with the arsenic is simply to put all of the arsenic into solution in order that all of it may unite with the lime to form arsenite of lime. When used with Bordeaux mixture this addition of lime is not necessary. Another arsenical poison and the one which Has largely displaced both Paris green and arsenite of lime as a stomach poison for use on foliage is arsenate of lead. In properly made arsenate of lead less than 1 per cent soluble arsenic is present, whereas in Paris green and arsenite of lime a much higher percentage of arsenic may be soluble or exist in a weakly combined state, and since it is this soluble arsenic which is injurious to foliage a much higher strength of the arsenate of lead can be used without danger of injuring the foliage. In addition to having this advantage the lead base makes the arsenate of lead much more adhesive to the foliage than either Paris green or arsenite of lime. The chief element in favor of the two latter arsenicals is that they are somewhat cheaper than arsenate of lead. However, within the past few years the increased consumption of ‘Se bs arsenaté of lead for spraying purposes and the sharper competition among manufacturers to secure the trade have been the means of considerably lowering its cost to the consumer and the matter of | price should no longer be a bar to its use. : 84 THE GRAPE ROOT-WORM. COMBININ G INSECTICIDES WITH FUNGICIDES. Since the use of a fungicidal spray for grapevines is highly desirable and frequently absolutely necessary to hold in check fungous dis- eases such as mildew and black-rot, and since some of the applica- tions for these fungous diseases and the insect pest may be made at the same date, it has become customary to combine the two treatments by adding poison in the form of arsenate of lead to Bor- deaux mixture, the fungicide used against the fungous diseases. The formula recommended for this combined treatment is asfollows: Pounds Copper-sulpkate (blue vitriol) .2.... 2.2 ce eee 5 Fresh ‘stone time... ose oe ee ee eee 5 Arsenate Of leads <3 02 Sed Oe ee oe 3 Water...clg oe sd oi Sete see Bas 25 oe 50 When Paris green or arsenite of lime are the arsenicals used, 4 ounces of the former, or 1 quart of the latter prepared according to Kedzie’s formula, may be added to 50 gallons of Bordeaux mixture. For reasons given above the use of arsenate of lead in preference to either of these other arsenicals is strongly urged. We here include detailed directions for making Bordeaux mixture which are given by Mr. C. L. Shear, of the Bureau of Plant Industry, in Farmers’ Bulletin 284, treating of fungous diseases of the grape. PREPARATION OF BORDEAUX MIXTURE. Failure to secure satisfactory results from the use of Bordeaux mixture is frequently due to lack of proper care and thoroughness in its preparation, or to the use of poor material. All ready-made preparations of Bordeaux mixture in the form of a paste or a dust should be avoided, as the chemical constitutents do not properly combine in these Breen e. A definite chemical compound isdesired, and this can only be produced in proper form and condition by care- fully following the directions given below: Stock solution.—In order to carry on the work with the greatest convenience and economy, a considerable quantity of copper sulphate and of lime should be ready for immediate use. The copper and the lime may be prepared and kept most conven- iently in the following manner: Copper sulphate solution.—Take 100 pounds of copper sulphate (bluestone), place it in a gunny sack, and suspend it in a 50-gallon barrel of water. Kerosene or whisky barrels will be found very convenient. The copper sulphate will all dissolve in from 12 to 18 hours if suspended in a loosely-woven sack, but if it is thrown loose in the bot- tom of the barrel it will take several days and considerable stirring to dissolve it. This REMEDIAL MEASURES. 85 makes a solution containing 2 pounds of copper sulphate to each gallon of water. This may be kept as long as desired without deterioration, if covered so as to prevent evaporation. Inme solution.—The various kinds of ground and prepared lime can not always be relied upon; stone lime is therefore to be preferred, and is more likely to give uni- formly satisfactory results. Slake 100 pounds of stone lime in a 50-gallon barrel, add- ing the lime in small quantities with sufficient water and mixing thoroughly. When the lime is all slaked fill the remainder of the barrel with water. You will now havea stock preparation of lime which when thoroughly mixed will be thin enough to dip, and pourreadily. Each gallon of this preparation will contain 2 pounds of stone lime. This may be kept under cover and used as needed. Where large quantities of mate- rial are being used it is desirable to have two or more barrels each of stock lime and bluestone instead of one, so that the bluestone in one barrel may be dissolving while that in the other is being used. . _. Mixing copper sulphate solution and lime solution. —To prepare a 100-gallon spray tank of Bordeaux mixture, take two 50-gallon barrels and fill them nearly full of water; to one barrel add 5 gallons of the bluestone stock solution, which will be soyeesi ee to 10 pounds of bluestone. To the other barrel add 5 gallons from the barrel of the stock lime preparation, which will be equal to 10 pounds of stone ime. Mix the lime thoroughly and allow the contents of the two barrels to run together in a trough, or through hose attached at the bottom of the barrels into the tank of the sprayer. If an insecticide is to be used, it may now be added to the mixture. After the mixture is prepared it should be used very soon, and not be allowed in any case to stand more than a few hours before using. The quantities mentioned in this account of the preparation of Bordeaux mixture will give 100 gallons of the 5-5-50 formula. For the other formulas, the manner of preparation is precisely the same, and the necessary changes in quantities of blue- stone and lime are easily calculated. PLANTS FOR PREPARATION OF THE SPRAY MIXTURE. Plate X, figure 1, shows a mixing plant erected beside a creek in a vineyard, using a hydraulic ram to elevate the water to the tank, the lime being slaked and the copper sulphate dissolved in the bar- rels standing upon the ground. An abundant water supply which can be delivered to the sprayer tank either by pressure or by gravity greatly minimizes both the cost and labor of preparing spray mix- tures and in addition saves a great deal of time at a season when the vineyardist is almost overwhelmed’ with the routine work of vine- yard operations. Lack of preparation for spraying operations and failure to utilize to the greatest advantage the flow of water down creeks or from springs adjoining vineyards, either by gravity or by the use of hydrau- lic rams, to elevated mixing stations frequently cause the vineyard- ist who is rushed with work either to neglect spraying entirely or to be so delayed in making the application that it is only partly effective; whereas if plans are made in advance to simplify the mixing and loading of the spray mixture, the apparent magnitude of the task is greatly lessened. The thing of prime importance is for the vine- yardist to become thoroughly convinced that spraying is one of the absolutely necessary operations in successful vineyard management. 86 THE GRAPE ROOT-WORM. TIME OF APPLICATION OF SPRAYS. Much time and labor is actually wasted in making spray applica- tions after beetles have done considerable feeding and deposited many of their eggs. The necessity of having all equipment and mate- rial in readiness to make the first application as soon as the first beetles appear can not be too strongly emphasized. There is no— doubt that the indifferent results secured from spraying by many vineyardists is largely due to failure to make the first application as soon as the first beetles appear upon the vines. | Unfortunately no definite date can be set for the making of this first application on account of the wide range in the date of emergence of beetles from the soil from year to year, due to variations in sea- sonal temperature conditions, especially during the spring months. Our records show that the beetles emerged fully three weeks later in 1907 than in 1908 and spraying operations had to be planned accordingly. Normally the first beetles may be expected to appear between the 20th and 25th of June. It should not be inferred, however, that the insect does not exist in the vineyards in scniees nitiieeee if the beetles are not in evidence at the latter date, for it happens that even experts have been led astray, as occurred in Chautauqua County, N. Y., in the spring of 1907, when experts visited the grape belt dur- ing the first week in July and, finding no beetles at this date, inferred that the pest no longer existed in very injurious numbers. Yet late in July it was found that beetles had emerged in enormous numbers in many vineyards throughout the area’visited. This emphasizes the fact that only by the closest observation can the vineyardist determine the damage which this insect may inflict upon his vines and he must be fully prepared every season to combat the pest on its first appearance. A more detailed discussion of the changes in time of emergence of the beetles from year to year is given under the head of seasonal history of the insect. NUMBER OF SPRAY APPLICATIONS. During this investigation it has been learned that two thorough spray applications will reduce this pest to numbers which will not materially affect the health of the vine or the production of profitable crops. The second application should be made about a week or ten days after the first to cover the growth of new foliage which has developed, and also to destroy those beetles which may not have emerged from the soil at the time the first application was made. Since rearing records indicate that the maximum number of beetles emerge within the period of ten to fifteen days after the first beetles appear (see fig. 23) the small percentage of late emerging beetles will not be likely to effect very great injury. The fact that there is some Bul. 89, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE X. SPRAYING OUTFITS FOR VINEYARDS, IN USE AT NorTH EAsT, Pa. Fig. 1.—Spray-mixing plant. Fig. 2.—Gasoline-engine sprayer inoperation. Fig.3.—Compressed- air sprayer, Figs. 4,5.—Horsepower or geared sprayers. (Original.) ‘ | REMEDIAL MEASURES. 87 danger of staining the fruit with spray applications made much later than the middle of July is an additional reason for making the second application not later than that date. | Nearly every season since spraying grapevines with a -poison has become a practice there has been more or less rumor concerning ill- ness -of persons by poisoning resulting from the eating of sprayed grapes. We have given considerable attention to looking up reports of this nature but have never been able to secure direct evidence of poisoning of persons in this manner. From our observationsand Fic. 80.—Young grapevine sprayed wiih arsenate of lead against the beetles of the grape root-worm. North East, Pa., 1909. (Original.) experiments with poison sprays against the grape root-worm beetle and all other insect pests known to us at present in vineyards in the Lake Erie Valley, all applications should be made in normal seasons not later than the middle of July, and in exceptionally late seasons like that of 1907 not later than July 25. If vineyardists will en- deavor to make their last poison application before that date they need have no fear of either staming their fruit or creating cause for rumor of poisoning by persons consuming the same and also may feel assured that they have made the applications at a period when they will prove most effective in the control of this pest. 88 THE GRAPE ROOT-WORM. PRESSURE TO BE MAINTAINED IN SPRAY APPLICATIONS. In order that effective results may be obtained with poison sprays — 2 it is very desirable that, as nearly as possible, all of the foliage be covered with a mistlike spray. (See fig. 30.)° Since in many vine-— yards having thrifty growing vines the foliage is quite dense during the latter part of June and early July it is necessary that this finely divided spray be thrown into the vines with considerable force. For effective work a steady pressure of not less than 100 pounds should be maintained and if this can be increased to 125 or 150 pounds still better work may be accomplished. SPRAYING APPARATUS. In order to cover vineyard areas of several acres in this manner it has become necessary to use power sprayers and during the past few: years several types of power vineyard sprayers have come into use. Horsepower sprayers.—Geared sprayers operated by horsepower (Pl. X, figs. 4, 5) are in general use in many vineyard sections. There are a number of sprayers of this type upon the market. With many of them, however, it is difficult to maintain a sufficiently high pressure to cover thoroughly all of the foliage without driving through the vineyard at too rapid a rate. In addition to this the nozzle arrangement is not adjusted so as to cover the foliage on the top of the trellis. A very unpleasant feature in the operation of many of these machines is that the driver is seated directly between the nozzles which are attached to the sides of the machine and consequently is drenched with the spray. It would seem however, that with a little ingenuity on the part of the manufacturers this unpleasant seating position and ineffective nozzle arrangement could be satisfactorily adjusted. Gasoline-engine sprayers.—Many vineyardists prefer to have the power for pro- viding pressure independent of the rate at which the machine travels through the vineyard and more directly under the control of the operator than it is with the geared sprayers. Since, however, the regulation gasoline-engine outfit used for spraying — orchards is too heavy and cumbersome to use in the narrow rows of vineyards it has become necessary to mount the tank and machinery on aspecially constructed shortened truck having low front wheels to admit of easy turning into the narrow vineyard rows. Plate X, figure 2, is an illustration of this type of gasoline-engine vineyard outfit and is the sprayer used for the past three seasons in making the application of poison sprays in the field experiments conducted during this investigation. An outfit of this kind has the additional advantage of being adaptable for use as an orchard outfit by simply disconnecting the fixed nozzles at the pump and connecting a lead of hose and rod when wishing to spray trees. It was for the purpose of tree spraying that the derrick or platform was erected above the tank. When used for vineyard work the derrick proved useful as an elevated seat where the driver would be clear of the Spray: (See Pl. X, fig. 2.) : Gre rand outfits. —Compressed-air outfits are a type of sprayer which find favor with a number of vineyardists and perform excellent work. The air is com- pressed by means of a stationary engine at the loading station and one of the cylin- drical tanks is charged with air and the other filled with the spray liquid. The two tanks are connected so that the air may pass into the tank containing the liquid and force it out through the nozzles in the form of a fine spray. Since there is no machin- ery connected with this sprayer except at the loading station there is practically no danger of delay from machinery getting out of order while working \in the field. a ae, a RECOMMENDATIONS. 89 Carbonic-acid-gas sprayers.—Carbonic acid is employed as power in a similar manner to compressed air. It is, however, somewhat more expensive than either horsepower engines, gasoline engines, or compressed air. More or less difficulty sometimes occurs in procuring the drums of gas, which have to be obtained from large cities where this gas is manufactured. Yet there are many of these outfits in use and giving good satisfaction. ; - Hand pumps.—Where but limited areas of vineyard are to be treated quite effect- _ive work may be done with a pump operated by hand to treat vines, and in gardens or places where it is impossible to drive a cart a knapsack sprayer may be used. For larger areas, however, it will be found more economical to use power outfits. The care of spraying apparatus.—For the successful operation of spray pumps it is highly desirable that the working parts be made of brass, since iron is acted upon _ by Bordeaux mixture. It is also important that the pump be so constructed that packing can be conveniently removed and replaced. Each time after the pump is used a few pailfuls of water should be run through the pump, hose, and nozzles to remove all of the spray mixture so that sediment in the mixture may not dry up and clog the valves and nozzles while the machine is not in use. If this precaution is taken much annoyance may be avoided when the machine is next put in operation. Nozzle adjustment.—Practically all of the power sprayers are equipped with adjust- able nozzles attached to a vertical rod firmly fastened to the sides of the tank, usually at the rear end of the machine. There are usually two or three of these nozzles set horizontally to throw the spray into the side of the vines. In addition to these hori- zontally directed nozzles, the uppermost nozzle should be carried out over the top of the trellis and directed downward to insure the covering of all the (— ~ foliage on the top of the trellis (Pl. X, figs. 2, 3), ™ “Lee 5 _ atts since it is upon the new growth developing at the top MMT qu of the trellis that the beetles are likely to do much ee feeding, especially after the lower foliage has been _ thoroughly covered with a spray mixture. Nozzles.—Nozzles of the Vermorel type are the kind in general use for vineyard spraying and pro- duce a fine mistlike spray which is so necessary for effective work, and for this reason they are more desirable than nozzles of the Bordeaux type, which throw a heavier, fan-shaped spray. The chief drawback. with the ordinary Vermorel nozzles lies in the rapid wearing out and enlarging of the opening of the cap, resulting in a coarse spray if allowed to become too much worn. More recently larger nozzles of the Cyclone type (fig. 31) have come into general use, especially where high pressure with power machinery is used. These nozzles throw a larger cone of spray, have steel disks for caps, which can be removed when the opening becomes much worn, and possess the added advantage of not clogging so readily as the smaller Vermorel nozzles. Fie. 31.—A large nozzle of the cy- clone type. (Original.) RECOMMENDATIONS. DESTRUCTION OF THE ADULTS OR BEETLES. The beetles of the grape root-worm feed upon the upper surface of the leaves of the grapevine, and may be poisoned by thoroughly spraying the foliage of the vines with an arsenical. The first poison- spray application should be made as soon as the first beetles are found upon the vines. Our observations indicate that thé beetles feed much more freely immediately after emergence from the soil 90 THE GRAPE ROOT-WORM. than they do several days later, during the period of egg deposition, and since the object of this application is to prevent egg deposition, it is very desirable that the poison application be made early, so that the first meal of the beetle will consist of poisoned foliage. The beetles may be expected to appear on the foliage during the last week or ten days in June or the first few days in July, depending on the earliness of the season. After June 20 vineyardists should keep a sharp watch for their appearance and have their spray equip- ment in readiness to make the first spray application. The development of the pupa in the soil will also indicate approxi- mately the appearance of the beetles, for they may be expected to appear within a week or ten days after the pupe can be found in the soil in considerable numbers. Since a large majority of the beetles emerge from the soil from ten to fifteen days after the appearance of the first beetles, it is necessary to make a second spray applica- tion within a week or ten days after the appearance of the first beetles. In this way it will be possible to keep the foliage well — covered with poison spray during the emergence of a maximum number of the beetles. Observations and experiments indicate that, if these two appli- cations are made promptly and thoroughly, this pest can be reduced to such small numbers that it will not materially affect the vigor of the vines. The spray formula recommended is as follows: PSE NAC ObeAd oc Sete Line ee See ieee eee pounds.. 3. Waar ee co Stee bh Pee wenn i ee eee eee gallons.. 50 Copper sulphate (blue .witeol). 0-2 242222522 eel ee pounds.. 5 Lime. (isesh “lump ivme) 322220 eee ee a ee ee do. 228 The first ingredient of the formula, arsenate of lead, is the arsenical poison and the active killing agent or inseeticide. The two last | ingredients, copper sulphate and lime, with the water, form Bordeaux mixture, which is a fungicide used to control black rot, mildew, and other fungous diseases of the grape. Fortunately this insecticide and this fungicide can be mixed without changing the quality of either, and for this reason their use in combination is recommended. DESTRUCTION OF THE PUP. In the vineyards throughout the Lake Erie grape belt pupation of the grape root-worm may be expected to commence about June 10, reaching the maximum about June 15 to 18. These dates can not be fixed, however, on account of variation in weather conditions. The exact time of pupation of the insect can best be determined by | the person operating the infested vineyard by carefully removing the soil around the base of infested vines to a depth of from 2 to4 inches. RECOMMENDATIONS. QO] When pupe are discovered, the soil beneath the trellis should be removed by the horse hoe and the soil directly around the base of the vine carefully and thoroughly stirred with a hand hoe. The efficiency of this method of destroying the pupe may be increased by throwing up a ridge of earth beneath the trellis during the last cultivation of the preceding summer. This will tend to encourage _ the insects to form their pupal cells above the roots of the vine and thus admit of their destruction by cultivation without serious injury to the roots of the vine by the horse hoe. It is in these two stages—namely, the pupa and the beetle—that the insect appears to be most readily overcome; in fact, no effective measures have yet been developed for the destruction of the larvee or of the eggs. Experiments conducted against the larve in the soil with oils, carbon bisulphid, fertilizers, salt, etc., have proved ineffective, and in some cases injurious to the grapevine; and simce the eggs are deposited beneath the bark of the canes when the vmes are in full foliage, it is practically impossible to reach them with a spray application. GENERAL TREATMENT OF INFESTED VINEYARDS. In addition to these recommendations dealing with direct means of controlling the insect in producing vineyards, a few suggestions are offered concerning the care and treatment of newly planted vines, and also of old, run-down vineyards in relation to this insect problem. Serious injury is most likely to occur to young vines planted in soil on which infested vines were growing during the preceding season, for this soil is likely to be heavily infested with grape root- worm larve which will transform to beetles. These emerging beetles readily discover the newly planted vines and soon riddle the leaves of these small plants. For this reason it is very desirable, when the replanting of an old vineyard area is found necessary, that some annual crop be grown for at least one season, in order that the soil may be free of the insect when the new vines are planted. In order that newly planted vines may be maintained in a thrifty condition during the period between planting and the bearing of the first crop of fruit, the vineyardist should keep a sharp watch during the month of July for the appearance of the grape root-worm beetles upon his young vines. When the beetles are numerous, they skele- tonize many of the leaves, and this greatly retards the growth of the plant. If the infested vines are thoroughly sprayed with arsenate of lead at a strength of 3 pounds to 50 gallons of water, the injury by the beetles may be in a great measure prevented. > ; a ae e O9}ie THE GRAPE ROOT-WORM. | sf There is little danger that young vines will become reinfested dur- ing the first season, since there is a very limited amount of cane or stem upon which the beetle can deposit its eggs. By the second sum- mer, however, the area upon which eggs may be deposited is somewhat increased, and we have discovered occasional egg clusters of this insect under the loose bark of the short stem of 1-year-planted vines and have also found a few larve at their roots late in summer, indicating that permanent infestation may take place early in the life of the vine- yard. Hence it may be necessary to spray some vineyards from the time of planting. Generally it is during the third season’s growth of the vines, when the cane is trained to the trellis, that serious permanent infestation, by means of egg deposition by the beetle, takes place. The larve. hatching from these eggs are especially injurious to these young vines, which possess but a limited root system compared with that of an old- established producing vine. It is the opinion of the writers that the first year or two of fruit production of young vines exposed to infesta- tion is the most critical period of their existence, and especial care should be taken during that period to prevent infestation by the beetles. This can be accomplished by following the suggestions made on pages 89-90, giving directions for the destruction of the beetles. When vines in a producing vineyard have been badly injured by this pest, such vines may frequently be renovated by cutting them back to the ground, so that the limited vitality of the injured vine may be devoted entirely to the making of vegetative growth. A heavy application of fertilizer should be made, consisting either of barnyard manure or a commercial fertilizer containing a high per- centage of nitrogen. The vines should be thoroughly sprayed at the time the beetles make their appearance and thorough cultivation of the soil should be maintained throughout the season. The grapevine : possesses remarkable recuperative power and, as the results tabulated : in this paper, under the heading of field experiments, indicate, : responds bounteously to careful and generous treatment. : 1826. 1837. 1843. 1847. 1863. 1866. 1867. 1867. 1868. 1870. 1872. 1873. 1874. 1877. 1880. BIBLIOGRAPHY. Srurm, J.—Catalog meiner Insecten-Sammlung, Kafer, pls. 4 col., pp. 1-207. Devean, P. F. M. A.—Catalogue des Coléoptéres, Third Edition, Paris. Sturm, J.—Catalog der Kafersammlung von J. Sturm, p. 295. _Fidia lurida Dej., synonym flavescens Sturm Cat. 1826. Me.tsHemer, F. E.—-Description of new species of Coleoptera of the United States.s-<-oeecnee ieee 36-37 Genes; wild, food plants of grape root-worm. .-.. 20. 2252s0).2..-.4..52-22. 03. eee 13-14 Grapevine Colaspis. (See Colaspis brunnea.) Fidia. (See Fidia longipes.) ilea-beetle. (See Haltica chalybea.) Haltica chalybea, mistaken for grape root-worm beetle, description and habits......_...............- 17 Heteropus [Pediculoides] ventricosus, enemy of grape root-worm............ 222-2 eee eee ence ccnecce 51 Hippodamia convergens, enemy of grape Todt-wormh. . . 2 = 23 25-- 2. bo. snes eco eee 51 Hoplophora4 Phthiracarus] arctata, enemy of grape root-worm............-.-..-2------ eee een eeeeee 51 Insecticides and fungicides, combination................-.-..-------- Ree igchnosterna sp., enemy of grape reot-werm......- .. 2. 230... edie es) - 5 ep eee 51 Lasius brunneus var. alienus, enemy of grape root-worm....._.........-.----2--2-2----- eee een e eee ees | Lathromeris (Brachysticha) fidiz, parasite of grape root-worm .................-------.--.----- 22.81, 56-57 Macrodactylus subspinosus, mistaken for grape root-worm beetle, description and habits...........- 17 Nozzle adjustment for spraying vineyards. .......:..- 2.2: ot.2<: R22. 220s. Ae ee ee 89 Wozzles for Spraying vineyards. .<...---.-- ..2-2)256.22 224 sce sda ote ote eer 89 Paris green and Bordeaux mixture against grape root-worm beetle...............-.-..------------- 84 comparison with arsenate of lead and arsenite of lime as insecticide. ...............:.... 83-84 Pelieuloides ventricosus, enemy of grape root-worm. .. - . 222-0 25.2 2- 22.) 5 55-2. -2- ee 51 Pithiracaras arciatus, enemy of grape root-werm.. ..... 2.2... .2- 22 -ce2- + 50st 7-2 5 - = -e 51 Polychrosis viteana, mention as enemy of grape.-...--. wo teeseurdvecwer Ss. fenee dee rr 18 Redbud. (See Cercis canadensis.) Red-headed Systena. (See Systena frontalis.) Renovation experiment on old vineyard injured by grape root-worm.........-...-.--...----------- 75-80 young vineyard injured by grape root-worm...................--------- 80-83 Bhizegiyphus phytlorerz, enemy of grape root-worm. . ... ..... 2-2-0 00< 52-5650 2-25 s eee 51 Rose-chafer. (See Macrodactylus subspinosus.) Seienyine apparatus, Care: <2... -) 2. 1+ go eee ess ead oes ee snes Ja+ bee dees sot er 89 NOT RVI EMAL CMEISE Sect’ as ee ee TN aah eee tee ce Peer ba Sl os 88-89 Spray formula recommended against grape root-worm beetle................-....-.--.---------- ng 90 mixture; plants for preparation .....22.2-...-.2.2.5-t26o-2<0 228-25) eee 85 Sprays peains} erape reot-worm peetle- 2... ..2..... =... 2ea cede. 1 eee et = ee it eee 83-88 number of applications: =: 5-4 -22:.22-52 == eee fret a 86-87 5 pressure in applications. -........ Wess sky fees er 88 time of application. . .:... 5-42.25... 4554 3 ee 86 Staphylinus vulpinus, probable enemy of grape root-worm.............--.------------+-------«------ 51 Systena frontalis, mistaken for grape root-worm beetle, description and habits, remedy.............- 17-18 Telephorid enemy of grape root-werm.... . .-.....- .< - 52-22 5552s 328 gas - =o 51 Temperature records during breeding period of grape root-worm during 19093 at North East, Pa.... 43 Puphlecyba comes, mention as enemy of prape.........------2---ba-- .24205h eee so 18 Tyroglyphus [Rhizoglyphus] phyllorerx, enemy of grape root-worm.......-.-.--.-.---------++-+----- 51 Wineygrd. conditions in Lake Erie Valley... ....0... . =.=... 26 <2 - 0 else nba e <2 = = oe er 57-59 experiments with poison sprays against grape root-worm beetle, results.............----- 70-75 renovation experiments against grape root-worm, results................---..--.+-------- 75-83 Vineyards, recommended treatment of those injured by grape root-worm...-.....-.-.-.------------ 91-92 Virginia creeper. 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