Briann ieee sti os eee Steer reser t ineetene' ENE $ Crees 2 o 3 nana frat He ar oa pe oe eR piso a of i * % ~ : eet : 374) . cana seen debe cess ves tenant CORNELL . UNIVERSITY LIBRARY GIFT OF Cornell University Library 475 .N7N ic insect: “HC Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://archive.org/details/cu31924024536520 OY see 77 MEDICAL LIBRARY, monthly by the University of the State of New York BULLETIN 295 AUGUST 1903 New York State Museum FREDERICK J. H. Merrity Director Epuraim Porter Fett State Entomologist Bulletin 68 ENTOMOLOGY 18 AQUATIC INSECTS IN NEW YORK STATE A study conducted at the entomologic field station, Ithaca N. Y; under the direction of EPHRAIM PORTER FELT D.Sc. Py JAMES G. "NEEDHAM Ph D. Professor of biology, Lake Forest University ALEX. D, MacGILLIVRAY Ph.B. O. A. JOHANNSEN M.S. Instructor in entomology, Cornell University Instructor in civil engineering, Cornell University K. C. DAVIS Ph.D. Professor of horticulture, West Virginia University ’ } a? PAGE PAGE Preface: jocccpacvscsee-sesen sek ses 199 | Part 5 Aquatic Chrysomelidae and a Part 1 Station Work of the Summer Table of the Families of Coleopter- of 1901. J. G. NEEDHAM....... 200 ous Larvae, A.D. MACGILLIVRAY 288 Part 2. Food of Brook Trout in Bone oo e MOR a Dip- é era, O. A, JOHANNSEN......-. 32 sae nee ca ice geanieiae 204 | Part 7 Sialididae of North and South Part 3. Life Histories of Odonata, Msdticas Io CoDAVisecss cdc 442 suborder Zygoptera. J. G, NEED- Explanation‘of plates......---.---- 487 HAM ..-. .----- e202 ee ee cee eee 218 | List of text figures......---------- 499 Part 4 Some New Life Histories of Plates 1-52......- Baten Aca hes face 499 Diptera, J. G. NEEDHAM...... 5B 7G: || UM EX 015s atise Seasibecen te oereeees 501 ALBANY UNIVERSITY OF THE STATE OF NEW YORK 1903 Mero4m-Jl2-3000 Price 80 cents ue 1892 1878 1877 1877 1881 1881 1883 1885 1888 1890 1890 1893 1895 1895 1897 1900 Igol Igor 1902 1903 1903 1903 1903 1888 1890 1890 475 N7N317 ¢ 1903 Mes. nos. University of the State of New York REGENTS With years of election Wituram CroswELL Doane D.D. LL.D. Chancellor, Albany WuireLaw Reip M.A. LL.D. Vice Chancellor — New York Cuauncey M. Depew LL.D. a = — New York Cuarwes E. Fitch LL.B. M.A. L.H.D. -— - Rochester Wititiam H. Watson M.A.-M.D. LL.D. z= - Utica Henry E. Turner LL.D. = - = = Lowville Sr Crain McKetway M.A. L.H.D. LL.D, D.C.L. Brooklyn DanieEL Beach Ph.D. LL.D. - = = — Watkins CarRROLL E. SmitH LL.D. - - ~ - — Syracuse Puny T. Sexton LL.D. - - - - — Palmyra T. GuitrorD SmirH M.A, C.E. LL.D. - — Buffalo Lewis A. Stimson B.A. LL.D. M.D. - a New York ALBERT VANDER VEER M.A, Ph.D. M.D. - — Albany CuHaRLES R. SKINNER M.A. LL.D. Superintendent of Public Instruction, ex officio CHESTER S, Lorp MA. LL.D. -— - = Brooklyn THomas A. Henprick M.A. LL.D. - = — Rochester BenjJAMIN B. ODELL jr LL.D. Governor, ex officio , Rogpert C. PRuyn M.A. - = = = — Albany Witiiam NottrincHamM M.A. Ph.D. LL.D. - Syracuse Frank W. Hiccins Lieutenant Governor, ex officio Joun F. O’Brien Secretary of State, ex officio CHARLES A. GARDINER LL.B. M.A. Ph.D. LL.D. New York Cuarves S. Francis B.S. - - - - — Troy SECRETARY Elected by Regents 1900 JAMES RUSSELL Parsons JR M.A. LL.D. DIRECTORS OF DEPARTMENTS Metvit Dewey M.A. LL.D. State Library and Home Education James RusseLL Parsons jr M.A. LL.D. Administrative, College and High School Def ts FREDERICK J. H. Merritt Ph.D. State Museum . Tas ale fa aa: University of the State of New York New York State Museum FREDERICK J. H. Merritt Director Epuratm Porter Fett State Entomologist Bulletin 68 ENTOMOLOGY 18 AQUATIC INSECTS IN NEW YORK STATE PREFACE It is very gratifying to present the public with such a material addition to our knowledge of the aquatic insects of the State, an ecological group which has received almost no attention except from those engaged in a systematic study of the adults. There is no doubt that insects form an important part of the suste- nance of some of our most valued food fishes, as shown by Dr Needham’s studies of the food contents of trout stomachs. Mr Johannsen’s systematic and biologic study of these minute spe- cies will do much toward making possible their identification in the immature as well as the adult condition. The ability to identify young or immature forms is exceedingly important when studying aquatic insects, and the great attention given to the early stages is the most valuable feature of this collec- tion of papers. The publication of this bulletin marks another important step in an investigation on the value of insects as fish food. The consummation of this, as has been previously pointed out, is a work of years; and it is hoped that each season ' may be marked by substantial progress. The acquisition of new facts is a laborious process; and the several authors are to be congratulated on their success. This collection of papers will prove not only a source of in- formation but also an inspiration to all subsequent workers. E. P. Feut State Entomologist Part 1 STATION WORK OF THE SUMMER OF 1901 BY JAMES G. NEEDHAM In 1901 the entomologic field station was conducted at Ithaca. The results of extensive field work at Saranac Inn the preceding season had not been fully worked up, and it seemed desirable that this unstudied material should be reported on. Thus access to collections and libraries became desirable; therefore, when Professor Comstock generously offered the station work- ing quarters in his laboratory at Cornell University and the use of his library, his offer was gladly accepted. A less ambitious program of field work was arranged for this second season. But, on the other hand, systematic studies of more importance and value, were planned and successfully carried out. The field work of the season was directed toward the study of nematocerous Diptera, aquatic Coleoptera and the aquatic neuropteroid groups. Breedings of Odonata-Zygoptera were carried on in order to supplement the extensive collections made at Saranac Inn in 1900, and to furnish a better basis for the account of that group in this bulletin. Not many additional species were reared, but much valuable material was obtained for some of the species there insufficiently studied. Trap lantern and other miscellaneous collecting was done through the season. In addition to the breedings of nematocerous Diptera, conducted by Mr O. A. Johannsen with great diligence and success, numer- ous Perlidae and Ephemeridae were reared by Mr Betten and myself. Collections of aquatic Coleoptera were also made, and these, together with my own breedings in that group, Mr. Mac Gillivray has worked up, generously adding thereto previous un- . published breedings of his own. His account of the group pub- lished herewith is destined to be highly useful to students. of aquatic insects. The chief feature of the station work of this season was cooperation. The station and the entomologic laboratory of Cornell University worked together most agreeably. Common AQUATIC INSECTS IN NEW YORK STATB 201 use was had of the equipment of both. In addition to the studies made for us by Mr MacGillivray, Professor Comstock assigned two of his graduate students, Mr O. A. Johannsen and Mr K. C. Davis, to work on special groups which the station was desirous of having investigated; and their work, published herewith, speaks for itself. This arrangement has made it pos- sible to present now a larger body of work than the station independently, on its own limited resources, could have secured. The station sacrificed nothing in natural advantages by re- moval to Ithaca. While so little is known of aquatic insects, the fauna of one place is about as new as that of another. For biologic field work of any sort, Ithaca possesses very great advantages. It would be hard to find a place with more variety of situation easily accessible. This is nature’s contribution; and it is, of course, the first requisite of a field station. It rarely happens that so rich and varied a fauna and flora lie at the very doors of the laboratories in which their study may be most advantageously carried forward. East hill, with the university campus spread out on one of its terraces, has cool swamps at its head and the Renwick flats and Cayuga lake at its foot, and is seamed all down its front by narrow gorges cut by turbulent streams. Across the narrow valley West hill rises with like abruptness; but it is of more regular contour, and its upper, gentler slopes are check- ered by farms. Between the two hills at the head of the lake is a marshy flood plain, partly timbered, and traversed by sinu- ous creeks and bayous. Sheltered behind the present natural embankment of the lake is the Renwick lagoon, characteristic views of which are shown in plates 1, 2 and 20. This is a great natural aquarium, teeming with plant and animal life. It is also a natural foraging ground for many of the lake fishes. The open lake is but a stone’s throw to the northward, and the lagoon opens directly into one of the several nearby creeks. Plates 3 and 32 show situations along two of the creeks of East hill near the ‘university campus and 600 feet above the lake level. These are pictures of collecting grounds utilized in gath- 202 NEW YORK STATE MUSEUM ering material for the present report. They give but a scant idea of the great variety and picturesqueness of these streams. Within easy walking distance of the campus are streams of all degrees of swiftness and of all sizes from the large creek to the tiny rivulet. The two creeks that bound the campus on the north and on the south, flow gently in their upper reaches and again on the flats below, but they descend the steeps of East hill in a succession of cascades. The workers at the station who were more or less directly participating in its operations were the following: 1 Professor C. Betten, of Buena Vista College, Ia., special collector of Trichoptera for the Cornell University collection. Rearing caddis flies and stone flies and running trap lanterns for the station. 2 Mr O. A. Johannsen of Cornell University, graduate stu- dent in entomology. Collecting and rearing nematocerous Diptera. 3 Mr A. D. MacGillivray, instructor in entomology in Cornell University. Studying aquatic Coleopterous larvae. 4 Mr H. N. Howland of Lake Forest College. Studying Odonata, and experimenting with apparatus for quantitative collecting of the insects of shore vegetation. 5 Mr H. D. Reed, instructor in vertebrate zoology in Cornel? University. Collecting and studying aquatic insects and fish food. 6 Mr T. L. Hankinson of Cornell University. Studying and collecting the same. 7 Myself, in charge of station operations. The excellent companionship of this body of enthusiastic stu- dents, the satisfactory and regular progress of daily routine, the fine facilities of the laboratory, the rich library, the accessi- bility of good collecting grounds, the suitableness of the equip- ment of the station, the beauty of the environment, and the weekly diversion of the meetings of the Jugatad made the ses- sion one long to be remembered. Its work was done under exceptionally pleasant circumstances. 1Entomologic Club of Cornell University. AQUATIO INSECTS IN NEW YORK STATB 203 The results of our work in so far as made ready for publica- tion appear in the following pages. With the aid of Messrs Reed and Hankinson, I have studied the food of the 25 brook trout taken in Bone pond at Saranac Inn, as detailed in my first report [N. Y. State Mus. Bul. 47, p. 396], and now report on it. The food of these trout was almost wholly insects, and there | was found such a preponderance of a single species of gnat larva \ (family Chironomidae, order Diptera) in the food, as indicates that that species may prove of high economic importance in water! culture. In another brief article I have brought together the descriptions of a few dipterous larvae of unusual types. Most interesting, perhaps, is the larva of Epiphragma fasci- pennis, a burrower in fallen willow and buttonbush stems, lying on the banks of temporary ponds; a larva of enforced amphibious habits, its residence sometimes submerged, some- times exposed; and it has a mode of respiration suited to either condition. My chief contribution to this bulletin is the description of the life histories and habits of the damsel flies © (order Odonata, suborder Zygoptera). I have been able to des- cribe the nymphs of all our 10 genera and of 23 of our 42 known species, all these descriptions being new. Mr MacGillivray has prepared a table of families of coleop- terous larvae in general that will be of great assistance to stu- dents of this order. -His careful study of the respiratory ap- paratus of the Donacia larva solves the old, troublesome prob- Jem as to how that animal, dweller on the submerged roots of water plants, gets its air. His study of Donacia is complete for all species of the world fauna now known as larvae, and a considerable proportion of them are now described for the first time. Mr Johannsen introduces his study of the dipterous families, Blepharoceridae, Simuliidae, Dixidae, Culicidae and Chironom- idae, with a table of families of nematocerous diptera. His ~ account of the Simuliidae is a monograph of the species of the eastern United States in all stages of their development. In the Dixidae he gives a key to our species (imagos) and offers the first life history written for an American species. His treat- 204 NEW YORK STATE MUSEUM ment of Culicidae is a generic synopsis of the family—and much more; for he tabulates our known species of each genus, except Culex. His careful and complete treatment of the Corethriinae is specially gratifying because this subfamily has been neglected by other American students of Culicidae. In the Chironomidae, that Chironomus which is the chief article of diet for brook trout in Bone pond [see pt 2] is treated as completely as possi- ble. Life histories are offered in two genera new to our fauna. This is but the beginning of Mr Johannsen’s work on the Chiro- nomidae. Dr Davis’s paper is a monograph of the Sialididae of America, and will be of great service to students of this neuropterous family, since it brings together descriptions of all known Ameri- can species with an account of what is known of their life his- tories. There remain, of station material still to be reported on, some Chironomidae and a large number of bred Perlidae and Ephemer- idae. Part 2 FOOD OF BROOK TROUT IN BONE POND BY JAMES G. NEEDHAM I have already given in New York State Museum bulletin 47, page 395-96, a brief statement of the conditions under which there were obtained from Bone pond during the summer of 1900 the stomach contents of 27 brook trout for study. These trout were all taken with hook and line. They were all adults and had selected their food in the natural way from what the pond offered. The pond itself is a small natural body of water less than 300 meters in greatest diameter and nearly circular. It is with- out outlet and is surrounded by deep woods. 1 haye given a brief sketch of its shore vegetation in bulletin 47 on page 389-90, with mention of the commoner animals collected there. It con- tains no fish but the brook trout. It was artificially stocked years ago, and has been repeatedly replanted with fry. Of the three propagating ponds controlled by the Adirondack Hatch- ery, it is by far the most successful in trout production. From the beginning the trout have been able to maintain themselyesg AQUATIC INSECTS IN NPW YORK STATB 205 in large numbers. Most of the trout I saw taken from it in 1900 were rather lean, though otherwise in good and healthy condition, and suggested that possibly it was becoming over- stocked. , Of the 27 stomachs obtained, one was empty, and the con- tents of another were lost through the breaking of a bottle, leaving 25 for study. I give below in tabular form a bare state- ment of what these 25 had eaten, and follow it with an account of what has been learned elsewhere of the biology of the insects constituting their food. Table showing the stomach contents of 25 brook trout from Bone pond a) ¢/ al ¢| ¢]/ a] 8] 2 | 8]-s|/-2| 2] | 2] 2] &] 3 “ a7 zo, a & te ke : Bl oA s ° 8 Bo |) eela la 3/ 2! 2/28) Sc! 2 3 FI ct e"7 ; 67, & a a/ ea] alg od) & Ho) = 2 8 Bf ae a ee ee ee 3 3 g g S |S /£2 12 | 2] 2) 212/82] s ee 3 zi A 5 |6 |S |S |slaelajais] 4 aA 3 1 | 28 July Br fenccdnse|| io: festolsses)eccefoscalcesl 42. meer 2|;30 ‘* M24 sel, BE Zo) se sell TL: fleeces) SB sees ager 3 | 3 Aug. V4 a QP saseeil | erie ec date ee sole ee ae A) Be oe ix aces) Sieaialloc ees mails ccallaaial| sts cl Gclicy beaters hes 5 3 sf QSOs se 2) AO \ese he eclles seibeecasacuttoe sie ieee kee 6; 3 * 313 Decse(tZOr| A leewel Mh rece lec loci, eens 1 | a: EE 15 (340 |..-.]....] 2 i il Siejai lta a siat| oe wicie. a 8.| 3. G6 || 20) SDs] cage ses Sette) bind! oer eee 9 | 3 #8 Cleoext Af 12n) Dre asc: rmiares| Bieter! b 10} 3 Tae eso) | Sor eeee ee ceeeel Woe eel as eimai ses a Se | ea Pr aioe aie Vesa leeael| sane eee e 12; 3 *« 9} 1 fA lessen econ eseccres erodes ered ert need 13; 3 « Ocal AL, wats Bose 4/3 * a eee ee seme} 1 ad 15 3 ff SOL. |.o2 2.x panies | awl Bec 16 OE Wicca aiiis sueta tna 2 sai ae 17 3 12 hose eee | QT seme @ 18/| 3 * 30} 8| 3] 9 Serisi|faiaiots St Be ee eee misofe:|temete|| Fae L ses sone 20 Bi Teese Sebala Rens panies T ieiasie ane 21; 8 * VE es} OD) lees seceillemere wows a ae a i (dn ea | VRE, FRE ER PN NR 9 23 )15 *& 310 |....| 1 1. | sews wows wees [aww lenwe ene le 24/18 “* WS 2 oe ween ccine Sees sees | seca eens [Sees | tees rere 25/18 ‘ 248. clisesclecealveectees || 1 |eecelvewef asiare Total..; 2462 |444 | 64} 92/10) 4)77/ 2/ 7] 8 250 |.--- aA few brook trout scales. bOne little fresh-water mussel. eAntenna of adult ¢ chironomid of small size. dCarabid beetle claw. eSeolytid beetle elytron and two little adult Chironomids. 7Achorutes sp.? (Order Thysanura). 9 Three little adult Chironomids. 206 NEW YORK STATB MUSEUM In this table the food species have been arranged in what seemed to be the order of their importance as constituents of the food of the trout at the time and place taken. The totals, counting larvae and pupae of a species together, are 2906 Chironomus, 156 Corethra, 14 trichopter larvae, 2 nymphs of Aeschna constricta, 7 nymphs of Callibaetis,8 Atax crassipes, 250 (approximately) Daphnidae, and a few wholly unimportant things listed as miscellanies. The numerical ratio of these is 116.24 Chironomus, 6.24 Corethra, 10 Daphnidae, .56 trichopter larvae, .32 Atax, .28 Callibaetis, .08 Aeschna to each of the 25 trout. What may be the relative food value of these species is, of course, wholly undetermined. In arranging them in the foregoing table, I have taken into account only their relative size. I should be inclined to regard only the three first named in the table as of any considerable importance to the trout. To my mind the chief value of this table is that it clearly. indicates one species of economic importance to trout culture— the Chironomid of whose larvae and pupae an average of 116 specimens had been eaten by each trout. The largest number eaten by a single trout was 351, while three trout had eaten none at all. It is possibly significant, possibly only accidental, that the May fly nymphs were eaten chiefly by those trout that had found no Chironomids. NOTES ON THE FOOD SPECIES OF THE TABLE 1 Chironomus sp.? There can be no doubt that in Bone pond this is an exceed- ingly important species. Unfortunately, the day this fact be- came apparent, in the cursory examination of the food as taken from the stomachs, was the last day of study permitted us at the pond. What the species is, consequently remains unknown. Mr Johannsen has studied the larva and pupa systematically, and has treated them in part 3. His figures [pl. 49] should make the recognition of the species possible when other larvae shall have been obtained and bred. AQUATIC INSECTS IN NEW YORK STATE 207 Professor Forbes in his studies of Illinois fishes (the brook trout was not one of the fishes he studied), has clearly pointed out the importance of these small larvae as fish food: “Among aquatic insects, minute slender dipterous larvae, belonging mostly to Chironomus, Corethra and allied genera, are of re- markable importance, making, in fact, nearly one tenth of the food of all the fishes studied”! In his report? on the aauatic invertebrate fauna of the Yellowstone national park, almost every page testifies to the abundance, general distribution and ecological importance of Chironomus. On page 228 are given some observations indicating that it is of as great importance to young trout as to adults: The pond was swarming with mountain trout (Salmo mykiss), a few of which I dissected for a determination of their food. One of these an inch and a half in length had eaten Chironomus larvae and imagos chiefly, the remainder of its latest meal consisting of other insect larvae, not in condition to identify, and the entomostrachan Polyphemus pedi- culus. A second, an inch and a quarter long, had also fed on Chironomus in its various stages of larva, pupa and imago, but had made about a third of its meal of Entomostracha. Another, still smaller (.92 of an inch long) taken from the open lake among the small weeds growing on a flat, muddy rock, had filled itself with Chironomus pupae only, as had still another of the same size. A third specimen from this situation had eaten more larvae of Simulium than of Chironomus, and a fourth had also eaten Simulium larva and another dipterous larva unknown to me. J may add here that other young trout, in a small swift rivulet near the Lake hotel, were feeding con- tinuously, Aug. 9, on floating winged insects, mostly, if not all, Chironomus and smaller gnatlike forms. With these certain indications of the economic importance of the genus at hand, it is indeed time we were able to recognize its species. Mr Johannsen’s work in part 3 is a beginning in that direction. All the above mentioned references, as well as most others to immature stages wherever published, are to the genus only; and Chironomus is a great genus, and includes forms with considerable diversity of structure, habitat and 1Ill. State Lab. Nat. Hist. Bul. 2, p.483. 2U. 8. Fish Com. Bul. 11, p.207-56. 208 NEW YORK STATE MUSEUM habits. It is quite probable that with pond culture, as with agriculture, when real progress begins it will be necessary to recognize not only species, but also varieties of the more im- portant species. Notwithstanding the indefiniteness of our knowledge con- cerning Chironomus as a whole, it may be worth while to ven- ture some general observations concerning the habits of the genus, since these will explain some peculiarities of the table. Among the larvae attributed to the genus there is consider- able diversity of structure, and a very striking range of color. Color differences have led to the distinction “white larvae” and “red larvae” in such papers as the one above quoted. The distinction is arbitrary, however, and of very limited applicabil- ity. The range of color is continuous from bright crimson in some of the red larvae to translucent pale yellowish or green- ish in the others. Moreover, all are “white larvae” when newly hatched; and the red color is correlated with a consider- able increase in size without a corresponding development of the tracheal system in the body, and is due to the increase of hemoglobin in the blood plasma. In general, it may be said that the “red larvae” are larger, have-a more extensive devel- opment of blood gills, and live in deeper or less well aerated water; the “ white larvae,” most of which are not Chironomus. in the stricter sense, are as a rule smaller, have little develop- ment of blood gills or of hemoglobin in the blood plasma, and live in rapids, on shore vegetation in shallower, cleaner, better aerated water. The Chironomus of the foregoing table is one of the larger species, with larvae of bright red color. Many of them were alive when taken from the trout stomachs, and wriggled about as actively as if just taken from the water. In shore collecting none were found, but a few of their loose, flocculent gelatinous cases were found at the farthest reach of a long handled net (depth 5-6 feet). The species is doubtless a denizen of the deeper water, which is the proper feeding ground of the trout. It lives 1Several British species are characterized in their immature stages, and a good general introduction to the study of the biology of the genus is now available in Miall & Hammond’s The Harlequin Fly, Oxford 1900, AQUATIC INSECTS IN NEW YORK STATE 209: on the bottom in the midst of a very thin layer of silt and veg- etable debris covering the white sand. Its loose gelatinous case is covered with adherent silt, and takes on the general, protec- tive color of the bottom. As is well known, the larvae of the larger red species are among the most characteristic bottom forms in all our larger and deeper lakes, being usually asso- ciated with deep water mollusks (Pisidium) and caddis fly larvae. This distribution, the natural abundance of the larvae, and the constant succession of generations through the year, leaving no period of absence of the larvae from the water, con- stitute the claim of these larvae to economic importance. The pupae at first are red, but that color is generally quickly obscured by the development of the pigment of the adult insect. Within a few days at most after the transformation from the larva, the pupa rises to the surface and floats there, descending when disturbed, but quickly rising again. Pupae are less uni- formly distributed over the surface than are larvae over the bottom, for the wind may drive them together in great masses.. Pupae are often taken in numbers in a surface net in towing; larvae are rarely taken so, and then only at night, and in shal- low water, for the larvae often leave their retreats at night and go swimming considerable distances with figure-of-eight loop- ings of the body. : It will be seen in the table that, with the exception of trout 11, every trout that had eaten Chironomus at all had eaten either larvae or pupae largely in excess; a large number of one stage, few or none of the other. In the light of the differences in hab- its of larvae and pupae just stated, this should indicate that some of the fish had been feeding chiefly or wholly at the bot- tom, others at the surface of the pond. The larger number of larvae eaten may indicate either that larvae were more easily obtained, or that they were preferred, or that bottom feeding was preferred. 2 Corethra This is another form that is common in our northern lakes generally. It was not studied at Bone pond, and was collected there only by the trout. Corethra plumicornis is 210 NEW YORK STATE MUSEUM common in a pond on the campus at Lake Forest, and there I ‘hare observed its habits for several years. The larvae are free swimming and are found most abundantly ‘beyond the line of the shore vegetation. They are entirely transparent, except for two pairs of air sacs and some pigment in the eyes, and, generally, food in the alimentary canal, ap- pearing as a dark line through the middle of the body. Their transparency doubtless secures them some immunity from ene- mies. I have experimented with feeding them to a hungry nymph of a dragon fly Libellula pulchella. Placed in the nymph’s mouth, they were eaten with avidity, but, placed thickly in the water with it and swimming around within easy reach, none were captured or even reached after by the nymph. It was probably unable to see them, for it quickly seized water boatmen (Corisa) when substituted for the Corethra larvae. I very much doubt whether the trout can see them. If they are as abundant in Bone pond as they often are in my campus pond, even the considerable number shown in the table, might, I think, have been taken in the straining of the water through the gill rakers, without selection of any individuals for capture. The pupae of Coretbra are at first likewise transparent and free swimming, but soon rise to the surface and float there, like ‘Chironomus, and just before transformation, become darker ‘colored. The imagos settle on low vegetation around the bor- ders of the water, or rise, dancing in swarms in sheltered and sunny places. The females deposit the eggs on the surface of the water, laying them down flatwise, in a spiral held together by scanty gelatine. : Among insects these larvae are the most independent of the shore vegetation. They feed on free swimming unicellular plants and animals. In my campus pond during April and May (the months of my observation) they live chiefly on a species of Peridinium, with a sprinkling of other flagellate infusorians. Specimens taken freshly from the pond generally show a dis- tinct brown streak through the middle of the body, due to the. Peridinia eaten. They are not incapable of disposing of much AQUATIO INSECTS IN NEW YORK STATE 211 larger prey, however. Very frequently in my aquariums, after: the supply of other food has run out, I have found a larva, with another larva of its own species and nearly of its own size, two thirds swallowed and one third digested. We have but few species of Corethra, and they are much alike, and should be readily recognized generically in larval and pupal stages by comparison with the figures given on plate 39. 3 Unknown trichopter larva from bottom of Bone pond This is another species that lives outside the line of the shore: vegetation. Just outside that line, on bottoms shallow enough to be reached with a long handled sieve net, Mr Betten found the cases of the species in great abundance, but they were all empty. He has described the case in bulletin 47, page 572, as. no. 2. Because all students of our lake bottoms have reported caddis: fly larvae along with Chironomus larvae as a constant part of" the fauna, I have thought it desirable to have the structural characters of this species illustrated as fully as possible in the hope of its recognition by comparison in the future. The only specimens seen were obtained from the trout stomachs, and were pretty well digested. Some of the cases were fairly well preserved, but the pupae were so badly disintegrated as to be hardly distinguishable as pupae; the parts of the larvae most strongly chitinized, and the parts most important for the dis- tinguishing of the species were fairly well preserved, and have been used, together with a perfect case collected from the water and apparently belonging to the same species, as a basis for the figures presented on plate 6. The trout swallow the animals case and all, doubtless being unable to get them apart. The case persists after the animal within has been disintegrated, but the sand grains gradually fall off, and the brown, lining tube of silk gradually breaks up into fragments. Most of the stomachs contained a little sand, doubtless derived from this source, and trout nos. 2, 3, 6, 7 and 17 contained large quantities loose, in addition to that still on the walls of the cases remaining. 212) NEW YORK STATE MUSEUM 4 Aeschna constricta The nymphs of this dragon fly live in the midst of the shore . vegetation in shallow water. The trout that eat them probably have to go beyond the confines of their usual feeding grounds to get them. The advanced stage of digestion in which the spec- imens were found seemed to indicate that the specimens had been taken during the preceding night. Aeschna nymphs attached to a hook were taken by the trout, but not more read- ily than minnows, small frogs or other bait. These were the largest animals the trout had eaten. The vol- ume of one of them would equal perhaps that of 15 to 20 Chi- ronomous larvae, or 30 to 40 Corethra larvae, or 5 to 7 caddis fly larvae, or 4 to 5 Callibaetis nymphs. They are among the most powerful members of the aquatic insect community and clamber about frequently on exposed places on plant stems, where the trout, if at hand, might easily seize them. . In a small way the dragon fly nymphs are competitors of the trout for food. They eat small insects promiscuously, and doubtless many pupae of Chironomus and. Corethra fall victims to them. They will eat young trout, also, as long as themselves. I demonstrated this at Saranac Inn by confining them together in a breeding cage. One little trout would be captured quickly, and then the others would be wary of the nymphs and keep away from them well, so that we would think they would evade a similar fate, but one by one they would disappear till all had been eaten. The Aeschna nymph approaches its prey with the slowness and poise and stealth of a cat till within striking dis- tance. Plate 5, figure B, shows a nymph of this species pois- ing for a stroke at a backswimmer (Notonecta). The adult dragon fly is shown also on this plate. Transforma- tion occurs in the latter part of June and in July. The female inserts her eggs by means of an ovipositor into the stems of plants just below the surface of the water. The eggs hatch in about three weeks, and the little nymphs at once take up their abode among the submerged plants and eat promiscuously any other animals they can overpower; they also eat one another, AQUATIC INSECTS IN NEW YORK STATE 213 I have not been able to determine as yet whether in relation to trout culture Aeschna is more disadvantageous than other wise. It eats a few of the fry and it eats the food of the larger trout; but, on the other hand, it furnishes a moderate supply of food itself for the larger trout. Out in the proper foraging ground of the trout, burrowing shallowly under the silt of the bottom of the pond, are other dragon fly nymphs of the genus Gomphus, which would seem to be wholly detrimental. They feed voraciously on other insects of the bottom fauna, and, doubtless, on Chironomus larvae, while by their burrowing habits they seem to escape the trout altogether. : 5 Callibaetis sp.? These nymphs, like the preceding, were found in an advanced stage of digestion. That they were Callibaetis, however, was determinable from the structure of the jaws, the top of the thorax and the bases of the setae, which were preserved. Since no adult May flies were collected at the pond and no nymphs bred, what the species is could not be established. Cal- libaetis ferrugina was taken at the hatchery, and the nymphs may very well have belonged to this species. This is a large genus, peculiar to the new world. A consider- able number of species are already described, and doubtless many more will yet be discovered. I have found the nymphs ex- ceedingly abundant in many small lakes and ponds. They are most abundant amid the shore vegetation, but wander out into deeper water, resting on the bottom, and darting rapidly from place to place. I think it likely that they will be found more important as the food of young fishes than of adults, because of their greater abundance in the shallower water. It is due to the occurrence of a new species! of Callibaetis in my campus pond at Lake Forest, where, with my students, I have watched it year by year, that I am able to give some facts respecting the genus, which have a bearing on its economic 1 While this is going through the press there comes to my table a description of the nymph of this species with figures by Berry, in the American Naturalist. 1908. 37:29, 30. 214 NEW YORK STATE MUSEUM status. The nymphs are associated with Corethra larvae, and, like them, are generally in excessive abundance at all seasons of the year. Unlike the better known May flies, this species has no single period of transformation; but imagos may be found beside the pond most of the time from April till September. There are, to be sure, as with Corethra, a larger number in evi- dence at the beginning of their season, about the middle of May, than at any time thereafter, but that, I think, is due to the cold weather retarding the process of transformation more than it retards growth. I have found the imagos quite abundant in September. This repetition and overlapping of generations makes for continuity of food supply in the water. The nymphs at transformation climb up only to the surface on some support, and then leave their cast skins floating on the water. The subimago stage lasts about 24 hours and is spent, as is usual, inactively. The male imagos are much in evidence, flying in little flocks in sheltered places in the sunshine, weaving up and down in their peculiar, rapid, dancing flight, and scatter- ing on the approach of a net and settling on the reeds so quickly and sitting so quietly that they usually entirely disappear from view. Ihave found it difficult to capture many specimens ofthis |. , species, even when they are abundant. The females are very seclusive. I have rarely found one flying with the males, or been able to discover one resting on shore. They are frequently seen floating on the surface of the pond, resting on the water with wings outspread, in which manner, like many other species of May flies, they deposit their eggs. I append a description of this species in both adult and nymphal stages. The accompanying figures will suffice for the recognition of the genus. The adults of the genus are recogniz- able by the costal band of brown on the wings, best marked in the female, and the generic characters of the nymphs are stated in the table for the genera of May fly nymphs given in bulletin 47 on page 419. AQUATIC INSECTS IN NEW YORK STATE 215 Callibaetis skokiana n. sp. Plate 7 Imago. Length of body 9-10mm; expanse of wings 18-20mm; length of setae, male 20mm, female 16mm. Ground color pale flesh tint, tinged with yellow (more yellowish in the female) marked, mottled and dotted with brown; antennae, legs and setae white. Head pale brownish, with whitish margins; in the male, occupied superiorly by the large turbinate superior portion of the compound eyes, which are pale egg-yellow on their superior, faceted surface, with paler margins, and which are as large as all the remainder of the head; in the female the top of the head is very flat, and is traversed by two longitudinal, irregular, pale brown bands, which are surrounded and separated by whitish. Prothorax paler, thickly dotted with brownish color. Dorsum of the mesothorax with a pale, longitudinal median suture, each Fig. 1 Wings of Callibaetis skokiana, male side of which is a band of brown rounded off posteriorly, and at the sides there are brown spots inferiorly. The median narrow pale line is continued posteriorly to the abdomen, and there are brown spots on the sides of the metanotum. Sides of thorax irregularly speckled with brown. Legs white with darker mark- ings at the knees and at the ends of the tarsal segments, the last one of which is wholly washed with brown. Wings with the usual costal band, differing in' the sexes, behind which they are hyaline. The band in the female is darker and better de- veloped. It covers proximally the bases of all the veins and is regularly narrowed to the apex, ending just before the apex of the wing, not lobed posteriorly, fenestrate with hyaline on most of the cross veins except toward the base, and reduced to a yel- lowish wash in the stigmatic region and about the humeral cross vein. In the male the costal fascia is paler, and usually disappears just before the yellowish stigmatic space, which is sometimes filled with anastomosing cross veins. The venation of the male is shown in figure 1. There is much variability in the 216 NEW YORK STATE MUSEUM number of cross veins in any part, but in general they are more numerous in the female. Behind the costal brown band in the female there are about 70 cross veins, not in a single row, not in regular rows at all. Gidea pale yellowish or flesh tinted, thickly dotted and dashed with brown, tending to form a dark middorsal band, more or less completely divided on the base of each segment, a line of brown dashes each side just above the pale lateral margin on segments 1-9, with a more or less separate curved mark above the anterior end of each dash. At the sides the metathorax overlaps the first abdominal segment and almost reaches the base of segment 2. The ventral side of the abdomen is paler with more uniform dots and a pair of submedian brown ()- marks iin ' Lal e ee ae Fig.2 End of abdomen of Callibaetis skokiana, male, ventral view, showing forceps, rudimentary median caudal filament and bases of lateral filaments on segments 2-9, abbreviated on segment 9. Forceps of the male [figure 2] and setae of both sexes pure white. Subimago. Differs in having the setae shorter (about 9mm long in both sexes), the wings faintly smoky brown, or slightly tinged with yellowish on the middle of what is to be the costal band, and the principal bands of brown on the body faintly indi- cated. Nymph. Length of body 12-13mm, setae 6-7mm additional; width of head 1.2mm, of thorax 1.8mm. Color greenish, marked with pale fuscous. Head pale, suffused with brownish around the eyes and across the ocelli in front, a longitudinal band bounding each eye inter- nally, tinged with yellowish. Prothorax pale marked with fuscous on the front margin and at the sides, with a pair of pale spots. in irregularly contoured brown inclosures on the dorsum. Mesothorax and metathorax darker dorsally with pale markings at the front margin and at AQUATIC INSECTS IN NEW YORK STATE 217 the rear between the wings; brown spots on the base and in the furrows of the wings. Legs pale, smooth, somewhat infuscated on the tarsi. Abdomen with a median dorsal interrupted band of brown, preceded by an urceolate divided brown mark on the metatho- racic dorsum, furcate anteriorly on segment 1 of abdomen, broadly overspreading segments 2 and 3 with additional brown spots at the sides and divided by paler apically; reduced to a slender T-mark on 4, the T-mark and Jateral spots reappearing on 5, the T-mark joined to an apical transverse line on 6, and on 7, fused with the lateral spots, a median line with lateral ()-marks on 8 and 9, 10 with the line and the margins narrowly (the apical margin more broadly) fuscous. ” Gills on segments 1-7, on 7 simple, and almost symmetric, a slightly indicated basal lobe on the posterior side, on 6, 5, 4 and 3 this basal lobe is successively more pronounced, becoming separated by a deep notch on 8; on 2 and 1 this lobe becomes a third as large as the body of the gill under which it is then folded, and a shallow incision appears on the anterior side of the body of the gill, nearer apex than base. All gills erect, with tracheae pinnately branched. The setae are pale with a wash of darker color near the tip. Other items in the food The eight water mites, Atax crassipes Miill., found in the food may well have been taken accidentally, as they are so small they could scarcely have been taken otherwise. The large number of Daphnidae found ina single stomach is a peculiarity for which I have no explanation to suggest. They were in an advanced state of digestion, and the number given is only approximate. There were fragments of what I took to be Daphniae in the stomach of trout 5 also, but scarcely recog- nizable. The difficulty of recognizing and counting these was quite in contrast to the ease and certainty with which the same things were done for the other food constituents. The heads of Chironomus and Corethra were most distinctive, and were the parts longest resisting digestion, so that among a mass of fragments it was only necessary to count the heads. The items listed as miscellanies were doubtless all accidental and unimportant. I think that the trout scales found did not indicate that any trout had been eaten, but only that they had been fighting, and this one had bitten another deeply enough to loosen a bit of its cuticle. 218 NEW YORK STATE MUSEUM Part 3 ae LIFE HISTORIES OF ODONATA SUBORDER ZYGOPTERA Damsel flies BY JAMES G. NEEDHAM The discussion of this suborder here is to be regarded as @ continuation of the study of the order from Museum bulletin 47, wherein the suborder Anisoptera was treated, and 62 life his- tories were detailed. Only the fauna of the State is discussed, and the bibliographic notes have here the same limited scope and purpose. No descriptions of imagos are given, but the reader is referred to well known descriptive catalogues, and it is hoped that the keys to imagos given herewith, together with the figures, may prove sufficient for the determination of our species. My purpose has been to make known the immature stages, and to that end, nymphs of all the species whose life histories are known are newly described. ; In the suborder Zygoptera 88 species have been listed from New York State hitherto: 36 by Calvert! and two additional by Davis. To this number we are able to add four species: Lestes vigilax from Cold Spring Harbor L. I; Enal- lagma piscinarium and E. pollutum from Ithaca and Nehallennia gracilis from Saranac Inn. Of the 42 species thus known from the State, we have reared 23, and — describe herewith, in more or less detail, their nymphs. All these descriptions are new, and apparently the first that have been written for our species though Hagen? has briefly stated the group characters of our genera of Calopterygidae. Of these 23, three are Calopterygidae, five are Lestinae and the remaining 15 are Agrioninae: and, fortunately, the nymphs of all our genera are now known. 1Thirty-five in his Odonata of New York State. N. Y. Ent. Soc. Jour. 8:39-48 and 5:91-96 and one in Hunt. News. 12:326. 2Preliminary List of the Dragon Flies of Staten Island. N.Y. Ent. Soc.. Jour, 6:195-98. 3EHssai d’un Synopsis des Larves des Calopterygines. C. R. Ent. Soc. Belg. 1880. 28:65-67. AQUATIC INSECTS IN NEW YORK STATE 219 In view of the fact that the nymphs of about half our species, including some of the commonest, are still unknown, a word to the collector, additional to what has been said in Bulletin 47, will bein order here. The Zygoptera are very easily reared. Nymphs taken when grown will transform readily in any sort of aquarium containing plant stems for them to climb on. Males should be bred for certain determination; and the male imago when well colored should be placed at once with its cast skin in a vial of 70% alcohol and promptly labeled. But, unlike most Anisoptera, the Zygoptera transform com- monly in the daytime; and it thus becomes a very easy matter at. the right time to pick up life history material. At the time when any species known to be locally common is just beginning to appear on the wing, one may go to its aquatic haunts, expect- ing to find with a little searching nymphs on stems near the surface of the water, others crawling out or transforming, imagos beside their recently abandoned nymph skins and teneral imagos taking flight. At this time it will not do to assume that all that look alike are the same species. Owing to the exceed- ingly close likeness of many of the species in such genera as Lestes, Argia and Enallagma, one must select males for certain determination, must keep each imago with its own cast nymphal skin, and must keep the imago alive till the form of the ap- pendages and the color pattern are fully developed. This last point is readily secured by placing the imago and skin when newly transformed in a paper bag for 24 hours, closing the top and avoiding undue jostling about at first. KEY TO FAMILIES AND SUBFAMILIES OF ZYGOPTERA Imagos a@ Quadrangle [see fig.8] of the wings divided by a number of cross veins; antenodal cross veins numerous; pterostigma lacking a special brace vein; wings rather broad............++. Calopterygidae aa Quadrangle without cross veins; antenodal cross veins but two in each wing; pterostigma with a brace vein at its proximal end in the space behind vein R,; wings narrower.............. Agrionidae. 220 NEW YORK STATE MUSEUM bd Vein M3 arising (i. e. separating from vein Mi+g) nearer the arculus than the nodus...... Lestinae bb Vein M3 arising nearer the nodus than the PEOUIUS: oases cece ailew Nae? PES MERAH EOS eo Om S Agrioninae Nymphs @ Basal segment of the antenna very large, as long as the other six together; median lobe of the labium with a very deep cleft; gills thick, the lateral ones triquetral..................000-- Calopterygidae aa Basal segment of antenna not longer than suc- ceeding single segments; labium with a very shallow closed median cleft or no cleft at all; gills thin, lamelliform......... 0.0... ee ee ee eee b Median lobe of labium with a short, closed, median cleft; lateral lobe trifid at end; movable hook bearing raptorial setae; gills Agrionidae showing transverse segmentation............, Lestinae bb Median lobe of labium entire; lateral lobe bifid at end; hook naked; gills various....... Agrioninae Family CALOL-TERYGIDAE This family includes in our fauna but two genera, Calopteryx and Hetaerina, both of which frequent strong flowing, perma- nent streams. The long legged, protectively colored, rather stiff and awkward nymphs cling to submerged vegetation, generally where it is washed by the current of the stream. KEY TO GENERA Imagos @ Basal space (space before the arculus) in all wings free ELON CrOSS VElNNs. core ek cena os kee SOs dase ees Be heen Calopteryx aa Basal space of all wings traversed by cross veing..... Hetaerina Nymphs @ Median cleft of the labium extending far below the level of the base of the lateral lobes; abdomen with- out lateral spines; dorsum of prothorax rounded at THE BIUER hea chan cian ee seu diee cuainnee ee gew Adan ta aes Calopteryx aa Cleft of the medium lobe of the labium extending only to the level of the base of the lateral lobes; lateral margins of abdominal segments 7-9 generally ending in smail, flattened lateral spines; dorsum of the pro- thorax with two angulate teeth each side.........., Hetaerina AQUATIC INSECTS IN NEW YORK STATE 221 CaALOPTERYX This strongly marked genus is abundantly represented about the borders of creeks and small rivers throughout the State, specially where such streams traverse rocky woods. The showy imagos, with their black or smoky wings, and bodies of brilliant metallic green, are very conspicuous, and‘ well known insects. They usually remain in proximity to their native streams, but sometimes follow paths for a considerable distance through adjacent woods. Their flight is poor and fluttering, and on windy or cloudy days they keep rather closely to shelter. The nymphs rest on silt-covered vegetation or on roots swaying in the current, and are rather inactive, moving but little from place to place. The known nymphs agree in the possession of long cylindric bodies, heads dorsally depressed, antennae with unusually de- veloped basal segment, exceeding in length all the other seg- ments put together, labium with a median cleft which divides the median lobe far below the level of the bases of the lateral lobes, a pair of spinules beside the cleft within, and three others at the base of each lateral lobe, legs long and thin, radiately arranged, gills three, variable in proportions, but always stout, the lateral pair with external carina, the middle one two-edged, all easily broken off, and generally wanting from specimens that have received too rough treatment. 222 NEW YORK STATE MUSEUM KEY TO SPECIES Imagos a Wings narrow; hind margin straight for a dis- tance, and parallel to front margin b Wings uniformly colored or transparent CGC Wings ClEar..... ce ccc ete ee en cece ener enes anguSstipennis co Wings yellowish. .......... 00sec cece eeeee amata bb Apical sixth of wings black...........-...-.06+ apicalis | aa Wings dilated, with hind margin visibly rounded vb Apical third of the hind wings blackish........ aequabilis bb Wings uniformly blackish or smoky............ maculata Nymphs a Basal segment of the antenna one third longer than the head is wide..............0eeeeaee aequabilis aa Basal segment of the antenna hardly longer than the head is Wide... .... cece cece eee cece enes maculata aaa Unknown ...........4. angustipennis, amata, apicalis Calopteryx angustipennis Selys 1853 Sylphis angustipennis Selys, Acad. Belg. Bul. 20:9 1854 Sylphis elegans Hagen, Monogr. Calopterygines, p.23, 9. 1861 Calopteryx angustipennis Hagen, Synopsis Neur. N. Am. p.56 1875 Calopteryx angustipennis Hagen, Bost. Soc. Nat. Hist. Proce. 18:20 (full bibliography and notes) 1889 Calopteryx angustipeunis Hagen, Psyche, 5:242 (descrip. tion) 1900 Calopteryx angustipennis Williamson, Dragon Flies Ind, p.253 (description and account of habits) This elegant, clear winged species has not been found as yet within the State, but Mr Williamson has found it locally abun- dant in western Pennsylvania. Its. nymph is unknown. Calopteryx amata Hagen 1889 C al opteryx amata Hagen, Psyche, 5:242 (original descrip- 1895 aise teryx amata Calvert, N. Y. Ent. Soc. Jour. 3:42 (listed from Keene Valley: descriptive notes) To the above record of a single capture of this species at Keene Valley, I have only to add the record of another capture on the other side of tbe Adirondacks, at Axton in June 1901, by Mr A. D. MacGillivray. The nymph is unknown. AQUATIC INSECTS IN NEW YORK STATE 223 Calopteryx apicalis Burmeister 1889 Calopteryx apicalis Burmeister, Handb. Ent, 2:826 (original description) 1861 Calopteryx aniealiz Hagen, Synopsis eeu N. Am. p.56 (description) 1875 Calopteryx apicalis Hagen, Bost. Soc. Nat. Hist. Proc. 18:21 (bibliography and distribution) 1889 Calopteryx apicalis Hagen, Psyche, 5:246 (a full descrip- tion) 1893 Calopteryx dimidiata, race apicalis Calvert, Am. Ent. Soc. Trans. 20:228 1895 Calopteryx dimidiata, race apicalis Calvert, N. Y. Ent. Soe. Jour. 3:42 (listed from Westchester county) ; 1900 Calopteryx dimidiata, race apicalis Williamson, Dragon Flies Ind. p.253 (description) This southward ranging species seems likely to be met with only at the lower altitudes in the southern parts of the State. Its nymph is unknown. Calopteryx aequabilis Say 1889 Calopteryx aequabilis Say, Acad. Nat. Sci. Phila. Jour. 8:23 1861 Calopteryx aequabilis Hagen, Synopsis Neur. N. Am. p.58 1875 Calopteryx aequabilis Hagen, Bost. Soc. Nat. Hist. Proc. 18:21 (bibliography and distribution) 1889 Calopteryx aequabilis Hagen, Psyche, 5:246 (full descrip- tion) 1899 Calopteryx aequabilis Kellicott, Odon. Ohio, p.9 (descrip- tion) 1900 Calopteryx aequabilis Williamson, Dragon Fiies Ind.. ae: 252 (description) 1895 Calopteryx aequabilis Calvert, N. Y. Ent. Soc. Jour, 3:42 (listed from Keeseville) This species is common near Axton along Stony brook and Raquette river. At Saranac Inn, 15 miles farther north, but two or three specimens were taken during the entire season. On July 31, 1900 Mr Betten and Mr Swett made a special trip down to Axton to get its nymph. All the specimens they brought back to Saranac Inn were kept there till the close of the season of our work, but failed-to transform. They showed however a greater length of basal segment of antennae than the nymphs of ©. maculata found at Saranac Inn, and have therefore been referred by supposition to C. aequabilis. By way of de- 224 NEW YORK STATE MUSEUM scription I will give the measurements of one of the largest nymphs, (length 28mm, antennae 5mm and gills 13.5mm addi- tional) and add that the nymph seems entirely like that of C. maculata except in its more uniform coloration and in the diagnostic character already stated in the key. Calopteryx maculata Beauvois The blackiving Plate 11 1805 Agrion maculata Beauvois, Jos. Afr. Am. p.85, Neur. pl.7, fig.3 1861 Calopteryx maculata Hagen, Synopsis Neur. N. Am. p.57 1875 Calopteryx maculata Hagen, Bost. Soc. Nat. Hist. Proc. 18:22 1889 Calopteryx maculata Hagen, Psyche, 5:246 (full descrip- tion) 18938 Calopteryx maculata Calvert, Am. Ent. Soc, Trans. 20:227 (description) 1895-97 Calopteryx maculata Calvert, N. Y. Ent. Soc. Jonr. 3:41 and 5:92 (listed from many localities in the State) 1899 Calopteryx maculata Kellicott, Odon. Ohio, p.8 (descrip- tion) 1900 Calopteryx maculata Williamson, Dragon Flies Ind. p.251 (description) This is our common species. In early summer it may be ob- served poising on some green twig beside any clear stream, or lending animation to the scene by the show of its brilliant colors in flight. At this season the cast skins may be looked for along any bank near which the imagos are flying, sticking fast to some support in a sprawling attitude close to the sur- face of the water. Nymph [fig.3]. Length 20mm, antennae 4mm and gills LLmm additional, 35mm in all. Elongate, slender, smooth; greenish brown, with a broad band of paler color nearly covering the flat upper surface of the head, and tapering backward on the thorax; paler rings on the middle of femora and gills; obsolete band of darker brown on the sides of the body, best defined on the sides of the thorax and rear of the head; a middorsal line of brown on the abdomen, inter- rupted at the sutures; gills usually paler at extreme tip. Labium [pl.14, fig.a] clongate, reaching posteriorly between the bases of the middle legs; no raptorial setae, but a spinule each side of the deep median cleft within, and three others at AQUATIO INSECTS IN NEW YORK STATB 225 the base of each lateral lobe. Movable hook strong, arcuate. Distal end of lateral lobe divided. Legs long, slender, smooth; no lateral carinae or spines on the abdomen; wings reaching the middle of the fourth segment; gills thick, with smooth and not very sharp carinae. In half grown specimens femora, tibiae and gills are often distinctly triple banded with brown, and the median cleft of the labium extends hardly below the level of the bases of the lat- eral lobes. The females descend on stems of more or less completely sub- merged aquatic plants (such as Elodea), and, unattended by the males, insert their eggs thickly into the green stems, just below the surface of the water. , HETAERINA This genus includes some of the most beautiful of insects. It is abundantly represented in the tropical parts of America; but for our State a single species is recorded. Another species. which occurs in Pennsylvania may yet be discovered within our borders. The common northern species, H. americana [pl.12], fre- quents slow flowing streams. The imagos are on the wing in late summer and early autumn, flitting about the borders of riffles. The males are very showy, and are easily distinguished from all our other dragon flies by the presence of a bright crimson streak on the base of each wing. Though their flight seems rather fluttering and uncertain, they are not very easy to capture when at the hight of their activity: they dodge quickly, and fly across stream frequently. Once, while collecting with a net of red mosquito bar, after trying vainly for half an hour to capture a specimen where specimens were not scarce, I stopped in Gis- couragement with the net under my arm, the bag behind me, and rested. A moment later, looking back over my shoulder, I saw a fine male Hetaerina sitting on the edge of my net. Care- fully disengaging the handle from my arm, I managed to sweep him into the bag. Then I turned my attention to the others that were fluttering about the stream, and found I could easily accomplish by strategy what I had failed to do by force. There . were few good alighting places about the stream, and I found 226 NEW YORK STATE MUSEUM | that, if I held the net motionless in front of a flying male he | would promptly alight on the edge of it. But specimens may be captured directly with little trouble at morning or evening, or on cloudy days, when they are less actire. Sometimes they assemble in large numbers on the pendant boughs of a willow bush beside a stream at evening, forming with their crimson streaked wings and bodies of black and bronze against the willow background, so charming a picture | that the collector will hesitate to disturb it. The nymphs cling to plants in the rapids; occasionally they live _ | on bulrush stems that fringe the wave-washed shore of a lake. Transformation takes place just above the edge of the water, and, with us, in the month of August. Our common species I have bred several times in widely separated localities. It does not occur at Saranac Inn. It has been several times taken at the head of Cayuga lake at Ithaca. This species (H. americana) may be separated from H. tricolor as follows: = KEY TO SPECIES a Tibiae with the exterior side yellow................00. americana aa Tibiae entirely black... ... 0... cee cece cece tee ence ees tricolor Hetaerina americana Fabricius Plate 12 - 1798 Agrion americana Fabricius, Ent. Syst. Suppl. p.287 1839 Lestes basalis Say, Acad. Nat. Sci. Phila. Jour. 8:35 18389 Calopteryx americana Burmeister, Handb. Ent. 2:826 1854 Hetaerina americana Selys, Monogr. Calopteryginae, p. 131, pl.12, fig.3. e 1861 Hetaerina americana Hagen, Synopsis Neur. N. Am. p.60 1863 Hetaerina americana Walsh, Ent. Soc. Phila. Proc. 2:211, 267 1875 Hetaerina americana Hagen, Bost. Soc. Nat. Hist. Proc. 18:23 1898 Hetaerina americana Calvert, Am. Ent. Soc. Trans. 20:228 1895-97 Hetaerina americana Calvert, N. Y. Ent. Soc. Jour. 3:42 and 5:92 (listed from Keeseville, Ithaca and Albany county) 1895 Hetaerina americana Kellicott, Cincinnati Soc. Nat. Hist. Jour. (habits) ° 1899 Hetaerina americana Kellicott, Odon. Ohio, p.4 1900 Hetaerina americana Williamson, Dragon Flies Ind. p.254 1901 Hetaerina americana Howard, Insect Book, pl.46, fig.11 1901 Hetaerina americana Calvert, Biol. Centr. Am. vol. Neur, p.26-29, pl.2, fig.1-17 (a most complete account of imago) AQUATIC INSECTS IN’NEW YORK STATE 227 This is the common and perhaps the only species in New York State. The above account of the habits of the genus has been written with this species in mind. It is as yet recorded from but three localities in the State, but it will doubtless be found in many other places when proper search is made for it. Its nymph has not been described, but in 1880 Dr Hagen drew char- acters distinctive of the genus from nymphs which he referred to H.californica, Haamericana, H.titia and an undetermined species from Brazil,! and Calvert? and Williamson® have used these characters in keys to American nymphs. Nymph. Length of body 17mm; antennae 4mm additional; gills 7mm additional. Color greenish or brownish, paler on the sutures, on legs and on margins of gill plates, but without distinct color pattern. Occasional specimens show faint indicr- tions of darker transverse bands on the tibiae and gill plates. Head flat above, with rounded eyes set well forward, with hind angles obtuse and having a much less distinct superior tooth than that of Calopteryx. Antennae long, inserted into large frontal prominences, somewhat shorter than the head is wide, the first segment longer than the following six, which rapidly and successively decrease = in length and thickness. Labium long, the hinge extending posteriorly between the bases of the middle legs; mentum suddenly | and greatly dilated in its apical half, its ( median lobe divided into two lobes by a yy, 4 sntenna, and end of median cleft, which is rounded basally and abdomen, shotving lateral extends barely below the level of the baseg ayer, of Br taerina of the lateral lobes of the labium; the distal end of the cleft is closed by the apposition of the two-divisions of the median lobe; beside the cleft on either side is a single small spinule. Each lateral lobe of the labium is straight on its outer margin, with a moderately strong and arcuate movable hook, just before the base of which on the superior margin are three small spinules. The exposed portion of the inner margin is strongly convex, and finely serrulate, and terminates after a sigmoid curve, in a short, stout, strongly arcuate end hook; 1Ent. Soc. Belgique, Compte Soma 23:65. 2Am. Ent. Soe, Trans. 20:225. 3 Dragon Flies of Indiana, p.247. 228 NEW YORK STATE MUSEUM above the end hook on the distal margin are two other strong hooks, the one next the end hook being twice the size of the other above it. Prothorax with a pair of elevated, round tipped prominences each side of the dorsum. Legs thin, smooth, long. Wing cases reaching as far as the base of segment 5 of the abdomen. Abdomen smooth, cylindric, with lateral margins becoming sharp posteriorly and generally ending on segments 7-9 in a sharp, flat, lateral spine. Gills variable in size, and easily broken off; the median one flat, the two lateral ones triquetral, all with thin margins, and apexes rather obtuse. Fig. 5 Hetaerina: male abdominal appendages; a, H. americana; b, H. tricolor Hetaerina tricolor Burmeister 1889 Calopteryx tricolor Burmeister, Handb. Ent. 2:827 1854 Hetaerina tricolor Selys, Monogr. Calopteryginae, p.136, pl.12, fig.5 1861 Hetaerina tricolor Hagen, Synopsis Neur. N. Am. p.61 1875 Hetaerina tricolor Hagen, Bost. Soc. Nat. Hist. Proc. 18:24 1893 Hetaerina tricolor Calvert, Am. Ent. Soc. Trans. 20:229 1899 Hetaerina tricolor Kellicott, Odon. Ohio, p.13 1900 Hetaerina tricolor Williamson, Dragon Flies Ind. p.255 1901 Hetaerina tricolor Howard, Insect Book, pl.46, fig.19 This handsome dark colored species is not as yet known from New York. Its nymph is unknown. | Subfamily LesTINa® A single genus is included within our fauna. LESTES This large and cosmopolitan genus is represented among us by a number of interesting and beautiful species. They are abundant in marshes, in shallow pools filled with standing aquatics and about the reedy borders of streams and ponds. They are rarely seen either over open water, or at any consider- AQUATIC INSECTS IN NEW YORK STATE ‘229 able distance from water. They habitually rest among the stems of tall growing rushes and sedges, or flit from stem to stem in short, shadowy flights, Notwithstanding the brilliant metallic colors of some species, they are by no means conspicu- ous in their native haunts; their greens and browns, and their slender bodies and transparent wings are lost against a back- ground of reeds and sedges. They feed extensively, perhaps chiefly, on such small gnats, mosquitos etc, as emerge from the water of their own native shallows, or such as rest in hiding during the daytime among the rushes. I have often seen a Lestes dart out and capture a gnat in flight, and then settle on a stem to devour it at leisure. The females (of two species at least, L. uneata and L. unguiculata) deposit their eggs in punctures made in the stems and leaves of plants above the water. For this purpose they utilize the leaves of bur reed or of any of the coarser sedges or grasses, or the flowering stems of the blue flag. The stems and leaves selected for oviposition, usually well exposed clumps here and there about the pools, are often filled full of eggs fora distance of a foot above the surface of the water. I have studied Lestes chiefly in the two species named above, which are common about my home in Lake Forest, occurring in shallow pools of the springtime, that dry out thoroughly every summer, and are usually refilled by the rains of late autumn. I have already published! some observations made there, on the destruction of the fruit of the blue flag by the puncturing of the - fruit stalks by Lestes ovipositing. I will give here some addi- tional observations of facts more immediately concerning the insects themselves. In these pools, which are always dried out by midsummer, the eggs, deposited well above the water, develop normally from the first, and in the course of two or three weeks attain a condition which is apparently almost that in which they will hatch. Then they estivate through the remainder of the sum- mer and early autumn. Development stops apparently entirely, 1American Naturalist, 34:374-75. 230 NDW YORK STATE MUSEUM and remains stopped till the pools are refilled in late autumn, and the stems and leaves, now dead, fall into the water. I have gathered the eggs in the middle of July and again in the middle of October and found them at apparently the same stage of de- velopment. Eggs placed at the latter date in a bowl of water in my laboratory hatched within a week. I did not try hatching any of them earlier. Exposed as they are above the water, these eggs are subject to parasites, which destroy often a large proportion of them. From a handful of bur reed leaves well studded with Lestes eggs, Fig.6 Theegg of Lestes uncata I once bred large numbers of the following parasites, the two last named being hyperparasites on the third named in the list. Brachista pallida Ashm. Centrobia odonatae Ashm. Polynema needhami Ashm, Tetrastichus polrnemae Ashm. Hyperteles polyneinae Ashm. The nymphs live among submerged plant stems. Their ex- tremely slender legs, long swaying bodies, and leaflike gill plates, together with a sober color pattern of greens and browns, render them very inconspicuous when in their native haunts. In aquariums they are rather shy, and do not feed under obgerva- tion so readily as do many other genera. I have observed them eating some of the larger entomostraca and smaller dipterous larvae (Corethra and Chironomus). Since the nine species occurring in or regional in New York State have all been described several times in recent and avail- able papers, and since the females are well nigh indistinguish- able, and determinations must at present be based on the males and chiefly on the form of the terminal abdominal appendages of the males, I have not thought it worth while to give deserip- AQUATIO INSECTS IN NEW YORK STATE 231° tions of imagos. I present a key based chiefly on the form of the male appendages, which will be sufficient, I trust, for the deter- mination of species. Of these nine species I have reared five. I regret to acknowledge, after prolonged study of them, that I find them well nigh indistinguishable specifically. Aside from slight and inconstant differences in size and a few very minor structural characters, they are all alike. I will give therefore a general description of them and supplement it with a tabular statement of such differences as I have thus far been able to discover between them. Nymph. The nymph of Lestes is exceedingly long and slender, with wide head, deep thorax and slender, cylindric ab- Fig.7 Nymphof Lestes rectangularis; -A, gills, more enlarged domen, bearing lincar-oblong gill plates. Head twice as wide as long, only moderately prominent at the front; eyes prominent, rounded, directed somewhat anteriorly; hind angles low, well rounded, with a shallow wide notch between them on the hind margin; antennae longer than the head, with the segments in- creasing in length to the third, and decreasing thereafter to the tip, seven-jointed. Labium [pl.14, fig.c] long and exceedingly slender, the hinge reaching as far posteriorly as the hind legs, but dependent, and not closely applied to the ventral surface of the body; mentum linear to the suddenly dilated, and spoon- shaped tip; median lobe moderately prominent, with a closed median cleft which extends as far proximally as the level of the bases of the lateral lobes; mental setae well developed; lateral lebe very complicated [see pl.14, fig.d], bent almost at a right angle just beyond its base, having a very large movable hook, be- yond the base of which the distal portion is cleft into two parts, the inner one of which bears the end hook and the usual inner series of teeth, these being very numerous, regular and deeply cut; the outer part is widened distally, with its distal angles pro- 232 ot NEW YORK STATE MUSEUM duced in long hooks, of which the outer is twice the larger and each of these hooks is separated by a shallow notch from a row of 5-9 minute teeth on the distal margin. There are three lateral] setae, two on the movable hook, and one just before its base. Prothorax conic, tapering forward to its attachment to the head. Legs very long and slender, generally faintly annulate with darker color. Wing cases narrow, elevated, their tips hardly reaching the base of the fourth abdominal segment. Abdomen cylindric, with lateral margins becoming sharp posteriorly, ending on the fourth or fifth to ninth segments in minute but sharp lateral spines; segments 2-9 of about equal length, 1 and 10 shorter and about equal each to the other. Gills long, with parallel sides and abruptly rounded ends, dis- tinctly segmented for part of their length, and generally trans- versely banded with brown. KEY TO SPECIES Imagos* a Inferior appendages of the male not longer than half the superiors b A large metallic green species: length of hind WiDE 25-29 MMs. ices ivedeae ss cedcraass eurina bb A smaller, blackish brown species: length of hind wing 18-22mm...............eeeuee congener aa Inferior appendages of the male abdomen longer than half but not longer than the supe- riors c Inferior appendages, viewed from above, exhib- iting a sigmoid curvature............... unguiculata ce Inferior appendages viewed from above, straight or nearly so d Metallic green species (when mature) j e Inferior appendages of the male viewed rad from above strongly dilated toward the UD ER ohne: caxieilehe'snolers wenaihna: e¥- Saks aoe uncata 4 ee Inferior appendages of the male very slen- 4 der and straight in their apical half..... vigilax i. dd Blackish brown species ‘ f Apex of inferior appendages of male bent ry downward at the tip................008 rectangularis ff Apex of inferior appendages not distinctly qt declined g g Inferior appendages of the male viewed from above slightly widened at the tip; of the two teeth on the inner edge of superior appendage, the basal one is - Mauch the larger.........-. 0.0... ccc cee forcipata 1After Calvert. Am. Ent. Soc. Trans. 1893. 20:229-32. AQUATIC INSECTS IN NEW YORK STATD 233 gg Inferior appendage of the male not wid- ened at tip; the proximal tooth on inner margin of each superior appendage little larger than the distal one............... disjuncta aaa Inferior appendages of the male longer than the superior, and bent inward and tufted with hairs at the tip................000. inequalis Here are the differences observed to exist between the nymphs of the species I have reared. Nymphs a@ On each side of the mentum five to six raptorial setae [pl.14, fig.c]........ forcipata and rectangularis aa On each side of the mentum normally seven raptorial setae b Length when full grown about 31mm............ unguiculata and uncata bb Total length when grown about 87MM.............ee ce eee eurina qua Unknown................ congener, disjuncta, vigilax and inequalis Lestes eurina Say 1839 Lestes eurina Say, Acad. Nat. Sci. Phila. Jour. 8:36 1861 Lestes eurina Hagen, Synopsis Neur. N. Am. p.70 1891 Lestes eurina Scudder, Psyche, 6:66 1893 Lestes eurina Calvert. Am. Ent. Soc. Trans, 20:229, pl.3, fig.14 1895 Lestes eurina Calvert. N. Y. Ent. Soc. Jour. 3:42 (listed from Dobbs Ferry) : 1900 Lestes eurina Williamson, Dragon Flies Ind. p.256 1901 Lestes eurina Davis, Nat. Sci. Ass’n Staten Island. Proc. v.8, no.3 (not seen by me) 1901 Lestes eurina Needham, N. Y. State Mus. Bul. 47, p.518 (men- tion of its habitat and associates) This large and handsome species was common at Saranac Inn about the edges of all sphagnum-bordered ponds, where it was associated with L. uncata and L. unguiculata, and with other genera. I bred it there on June 20, 1900, and again at Lake Forest Ill., where it is rather uncommon, on June 12, 1901. Lestes congener Hagen 1861 Lestes congener Hagen, Synopsis Neur. N. Am. p.67 1898 Lestes congener Calvert. Am. Ent. Soc. Trans, 20:229, pl.3, fig.15 1895 Lestes congener Calvert, N. Y. Ent. Soc. Jour. 3:42 (listed from Lake St Regis) 1895 Lestes congener Kellicott, Cincinnati Soc. Nat. Hist. Jour. 17:200, 202 1899 Lestes congener Kellicott; Odon. Ohio, p.15, fig.17 1900 Lestes congener Williamson, Dragon Flies Ind. p.256 234 NEW YORK STATE MUSEUM For this species I can only add a new locality to the records of its occurrence; I have taken it at Ithaca. Its nymph is unknown. Lestes unguiculata Hagen ' 1861 Lestes unguiculata Hagen, Synopsis Neur. N. Am. p.70 1893 Lestes unguiculata Calvert. Am. Ent. Soc. Trans, 20:280, pl.3, fig.16 1895 Lestes unguiculata Calvert, N. Y. Ent. Soc, Jour, 3:42 (listed: from Westchester county) : 1899 Lestes unguiculata Kellicott, Odon. Ohio, p.16, fig.23 1900 Lestes unguiculata Williamson, Dragon Flies Ind. p.257, pl7, fig.1 : This widely distributed species I have collected at two unre- corded localities in New York State, Saranac Inn and Ithaca. I have bred it several times in June at my home in Lake Forest Ill., where it is abundant. The metallic green of the mature males is very brilliant. Lestes uncata Kirby 1861 Lestes forcipata Hagen, Synopsis Neur. N. Am. p.71 1900 Lestes uncata Lirby, Cat. Neur. Odon, p.160 (renamed) 1893 Lestes uncata Calvert, Am. Ent. Soc. Trans. 20:230, pl.3, fig.18 1895 Lestes uncataCalvert, N. Y. Ent. Soc. Jour. 3:42 (listed from Keeseville and Ithaca). 5:92 (listed from Buffalo) 1899 Lestes uncata Kellicott, Odon. Ohio, p.17, fig.20 1900 Lestes uncata Williamson, Dragon Flies Ind. p.257, pl.7, fig.2: This species flies through most of the summer at Saranac Inn, and is a common midsummer species at Ithaca. It is a characteristic denizen of shallow woodland pools. In such a pool near Glen Ellyn IIll., I once saw dozens of nymphs in trans- formation at a time on May 30, and I have bred the species in many places. Notes on the oviposition of this species and the last have already been given under the account of the genus. Lestes disjuncta Selys 1862 Lestes disjuncta Selys, Acad. Belg. Bul. (2) 13:302 1893 Lestes disjuncta Calvert. Am, Ent. Soc. Trans. 20:231, pl.3, fig.19 1895 Lestes disjuncta Calvert, N. Y. Ent. Soc. Jour. 3:42 (listed from Lake St Regis, Keeseville and Ithaca) 1899 Lestes disjuncta Kellicott, Odon. Ohio, p.18 1900 Lestes disjuncta Williamson, Dragon Flies Ind. p.258. I have not seen this species at large. Its nymph is unknown. AQUATIC INSECTS IN NEW YORK STATE 235 Lestes forcipata Rambur 1842 Lestes forcipata Rambur, Ins. Neur. p.246 1861 Lestes hamata Hagen, Synopsis Neur. N. Am. p.70 1893 Lestes forcipata Calvert, Am. Ent. Soc. Trans. 20:231, pl, fig.20 1895-97 Lestes forcipata Calvert, N. Y. Ent. Soc. Jour. 3:43 and 5:92 (listed from N. Y. city, Ithaca and Schoharie) 1899 Lestes forcipata Kellicott, Odon. Ohio, p.19, fig.19 1900 Lestes forcipata Williamson, Dragon Flies Ind. p.258, pl.7, fig.3 This widespread species I bred in June 1896 at Galesburg III. and in June 1898 at Ithaca N. Y. It was not observed at Sara- nac Inn. I have always found the species about the borders of ponds of permanent nature. Lestes rectangularis Say 1889 Lestes rectangularis Say, Acad. Nat. Sci. Phila. Jour. 8:34 1893 Lestes rectangularis Calvert, Am. Ent. Soc. Trans. 20:231, pl.3, fig.21 ; 1895-97 Le stes rectangularis Calvert, N. Y. Ent. Soc. Jour. 3:43 and 5:92 (listed from Dobbs Ferry, N. Y. city, Ithaca, Saratoga lake, New Baltimore, Schoharie and Buffalo) 1898 Lestes rectangularis Kellicott, Odon. Ohio, p.20, fig.18 1898 Lestes rectangularis Needham, Outdoor Studies, p.62, 68, fig.63, 73 (account of habits and figures of imago and nymph) 1900 Lestes rectangularis Williamson, Dragon Flies Ind. p.259, pl.7, fig.5 This exceedingly attenuated species is quite similar in appear- ance and habits to the preceding, and its nymph, which I have several times bred, appears to me quite indistinguishable from that species. I did not find it at Saranac Inn. Lestes vigilax Selys 1862 Lestes vigilax Selys, Acad. Belg. Bul. (2) 13:306 1893 Lestes vigilax Calvert, Am. Ent. Soc. Trans. 20:232, pl.3, fig.17 1898 Lestes vigilax Kellicott, Odon. Ohio, p.20, fig.18 1900 Lestes vigilax Williamson, Dragon Flies Ind. p.259, pl.7, fig.4 This species has not been recorded from the State hitherto. It is found at Cold Spring Harbor, L.I. Its nymph is unknowa. Lestes inequalis Walsh 1862 Lestes inequalis Walsh, Acad. Nat. Sci. Phila. Proc. p.385 1893 Lestes inequalis. Calvert, Am. Ent. Soc. Trans, 20:232, pl.8, fig.24 236 NEW YORK STATP MUSEUM 1898 Lestes inequalis Davis, N. Y. Ent. Soc. Jour. 6:196 (listed from Staten Island) 1898 Lestes inequalis Kellicott, ain Ohio, p.21, fig.22 1900 Lestes inequalis Williamson, Dragon Flies Ind. p.260, pl.7,. fig.6 This species is as yet known only from Staten Island, but is. very likely to be found elsewhere. Its nymph is unknown. Subfamily AGRIONINAE KEY TO GENERA: Imagos a Spines on the tibiae very long, twice as long as the intervals between them............. Argia aa Spines of the tibiae hardly longer than the inter- & vals between them bd No pale postocular spots on the top of the head; sexes similarly colored ce Colors of dorsum blue and black; yellow beneath the thorax............0e eee eee Chromagrion ee Colors of dorsum red and black; stout species Amphiagrion cece Dorsum bronzy green; slender species....... . Nehallennia bb With round or ovoid postocular spots on the head d Sexes with a general similarity in color, the female often of a lighter shade; no up- turned, bifid process arising from the apex of the 10th abdominal segment (except in the species last in our list); the superior abdominal appendages of the male not strongly directed downward 400. IMWALO. es ccneeseanewa ews de eulens Enallagms dd Sexes strikingly unlike in color; a bifid pro- cess arising from the apical margin of the 10th abdominal segment in the male and the superior abdominal appendages strongly directed downward and inward é Males chiefly green and black, with nor- mal rhomboidal pterostigma; females with the orange of the abdomen cover- ing something less than the three basal Segments (becoming wholly densely pruinose with age)................ Sere Ischnursa ee Males yellow or orange, with ovoid stigma which does not reach the costal vein; females with the four basal seg- ments of the abdomen yellow or orange. Anomala grion AQUATIC INSECTS IN NEW YORK STATB 237 Nymphs @ Labium with no raptorial setae on the mentum within; gills broad, thick, dark colored, oval or oblong in shape and obtuse at APEX b chew sweeties ca. ee oe Uoe swe RRS aa Labium with mental setae; gills thinner, more pointed and narrower [pl.15] b Hind angles of the head strongly angulate e Gills widest beyond the middle; body slender; head half as long as wide............... ce Gills widest across the middle; body stouter; - head nearly as long as wide............. bb Hind angles of the head rounded d Labium with one mental seta (and a rudimen- tary second one) each side; antennae six- jointed; lateral lobe of the labium. with ' the distal end above the end hook hardly : : Genticulated ........ eee cece ween Saeeiets dd Labium with three to five mental setae each side (one may be smaller than the others), and end of lateral lobe denticulated dis- tinctly; antennae seven-jointed (with the possible exception of HE. anten- i natum) e Gills more than half as long as the abdo- men, lanceolate; third segment of anten- : nae less than a third longer than the \ second ; ' f Labium with four to six lateral setae, gen- erally with five, and with three (rarely four) mental setae each side; gills often with a definite color pattern............ ff Labium with five or six lateral setae, and with four mental setae each side; gills generally with no distinct pattern....... ee Gills less than half as long as the abdo- men, narrower and with a long tapering point; third segment of antenna more Argia Chromagrion Amphiagrion Nehallennia Enallagma Ischnura than a third longer than the second..... Anomalagrion ARGIA This is another large genus whose species are nearly all American, and whose habitat is chiefly tropical or subtropical. In New York State are recorded five species, and a sixth is regional and is included in this list. Of these six, four have been bred, and their nymphs are here described for the first time. 238 NEW YORK STATE MUSEUM In habits our species are somewhat diverse. In general, may be said that they frequent the borders of the larger bodi and streams of water, and both in the water and out of it aft transformation they cling to the surfaces of stones, piers, ti bers, bare banks, etc., rather than to vegetation. Imagos m be found squatting on a bare bank much more frequently thi clinging to its neighboring plants, but they will travel out amo: the plants when foraging, following then by preference a ba ‘path or roadway. The eggs are deposited mostly on the alga-covered surfaces which the nymphs will afterward cling. In ovipositing the ma usually retains his hold on the prothorax of the female, ai oe LT HAL KS ES RIESE eee re nsuset nico Fig. 8 Fore wing of Argia fumipennis, with quadrangle (g) of hind win when, as happens frequently with the first species of our li at least, she descends beneath the surface of the water to pla: her eggs at a lower level, he is carried along. The nymphs of Argia are usually recognizable at a glance, t reason of their thick set bodies and short, broad and dark ec ored gills. If these be not sufficient, the entire absence of ra torial setae from the mentum of the labium will certainly di tinguish them from all our other genera of Agrioninae. TI nymphs are so much alike that a generic description of the may be given here, saving much repetition. Nymph. Short and thick and usually dark colored, with sho: legs and short-oblong gill plates [pl.15,a]. The head is som what wider than long, flat above, with very prominent eye behind which the sides are parallel as far as the obtuse rounded hind angles, between which is a deep round posteri emargination. The antennae are six to seven jointed, wi the third joint longest. The labium [pl.14, e and f] is shor with hinge barely reaching posteriorly to the base of t] AQUATIC INSECTS IN NEW YORK STATE 239 middle legs; the mentum is less than a third longer than ‘wide; median lobe spinulose on its prominent free border; ‘no mental setae; lateral setae one to four; lateral lobe short, half as wide as long, with short, stout, movable hook and small end hook separated by a more or less distinct notch from the inner margin, and with one or more smaller teeth on the distal end above the end hook. Prothorax pointed anteriorly and fitting the rear emargina- tion of the head. Mesothorax and metathorax much thicker, Fig. 9 Outline of head of nymph of Argia apicalis with the wings borne at a considerable elevation. Legs short, usually banded transversely, and bearing spines as well as ‘hairs. Abdomen stout, somewhat tapering, and with its segments ‘decreasing in length to the ninth, the tenth again a little longer. Gills oblong about half as long as wide, obtuse at apex and generally with paler apical markings. Among alcoholic specimens frequently, and among fresh specimens occasion- ally, the gills are absent, being easily broken off. If their loss occur early in nymphal life, they are regenerated, and it is no uncommon thing to find a specimen with one, two or three of the gill plates of smaller size than the normal. The loss of the gills seems not to affect seriously the respiration of the nymphs. , 240 NEW YORK STATD MUSEUM The following keys will serve for the separation of our species. KEY TO THE SPECIES Imagos a Dorsum of the apical segments of the abdomen of the male blackish; pterostigma surmounting more than one cell, i. e. longer than the cell OTT AC iiercit aw oe seein ae aw auto ave were RINE putrida aa Dorsum of apical segments of abdomen of male , with blue restricted to W-shaped basal marks on segments 8 and 9; stigma generally sur- mounting somewhat more than a single cell.. translata aaa Abdominal segments 9 and 10 blue, 1-7 black..... tibialis aaaa Abdominal segments 8, 9 and 10 blue, 1-7 ringed with blue or violet b Colors light blue and black: humeral stripe of black very narrow, a mere line, suddenly widened at its lower end....... esse cece eeece apicalig bb Colors deep blue and black, humeral stripe of black very broad, broader than the preceding stripe Of bIUCke isk scsi s ba ead dee Ge maeaearess © bipunctulata bbb Colors violet and black; humeral stripe bifid superiorly, the posterior fork not reaching the LATE GAT A525 ccd ca.sbs aris o dheayndes Wn asere dase sg a sactvenacereys violacea Nymphs @ With a single very minute lateral raptorial seta........ putrida aa With three or four well developed lateral setae 0 With three well developed lateral setae (occasionally, a rudimentary fourth in apicalis) ¢ Median lobe of labium one third as long as it iswide apicalig ce Median lobe of labium one fourth as long as itis wide violacea bb. With four well developed lateral setae..............-- tibialis GGG UDKNOWD...... sc eee eee e eee eee bipunctulata and translata Argia putrida Hagen 1861 Agrion putridum Hagen, Synopsis Neur. N. Am. p.96 1865 Argia putrida Selys, Acad. Belg. Bul. (2) 20:385 1898 Argia putrida Calvert, Am. Ent. Soc. Trans. 20:232 1896 Argia putrida Kellicott, Cincinnati Soc. Nat. Hist. Jour. 18: 110 (observations on manner of oviposition) 1895-97 Argia putrida Calvert, N. Y. Ent. Soc. Jour. 3:48 and 5:92 (listed from Niagara, Ithaca, Schoharie and Buffalo) 1899 Argia putrida Kellicott, Odon. Ohio, p.23 (description and habits) 1900 Argia putrida Williamson, Dragon Flies Ind. p.261 (description and habits) 1902 Argia putrida Williamson, Ent. News, 13:67 (oviposition; feed- ing, fig. of eggs on pinnule of Osmunda. AQUATIO INSECTS IN NEW YORK STATD 24t This is our largest species. It was not common at Saranac Inn, though a few could be found at any time about the timbers by the shores of the larger ponds. I bred it there. I had pre- viously bred it at Ithaca, where it is very common, and during the summer of 1901 I bred from Fall creek many additional examples. The species is a common and characteristic one about the shores of the great lakes. It belongs on wave-beaten shores and in the larger and more rapid streams. In Fall creek its nymphs are found under stones in even the swiftest water, clinging, as stone flies cling, to the rocks. It is the only dragon fly to be found inhabiting such situations. Kellicott made some interesting observations on the species at Lakeside on Lake Erie. The species was ovipositing in pairs on the dock timbers. The females would sometimes descend the timbers into the water, carrying the males with them. The females would remain submerged a long time (once almost an hour) while ovipositing, but the males would disengage them- selves and come up out of the water after 5 to 20 minutes. The descent is made by the backing downward of the female as she reaches ever for new territory in which to distribute her eggs. Nymph. Length 17mm, gills 6mm additional, abdomen 10mm; width of head 4mm. Antennae seven jointed, the second joint one third longer than the first. The single raptorial seta of the lateral lobe of the labium is very minute, difficult to see at all. The median lobe of the labium is very prominent, about half as long as it is wide. In the center of the mentum is an elongate V-shaped chitinization, the V opening forward. The abdomen is relatively long, the wing cases reaching scarcely to the base of the fourth segment. The gills are more than twice as long as wide, with parallel margins and obtuse apexes, black- ish, with the apical fifth more or less covered with white. The head is more depressed, and the legs are more sprawling than in other species, due perhaps to the habitat. The stone flies and May flies living in rapids are modified in form along the same lines. At transformation the nymphs depart farther from the water than in the other species, often going several yards up the banks. The seasonal range for imagos of this species is from May ‘