dane mate “ TT 1 ee Wd hePqng pt ay tle ast rye ty yh Py sy: i Lrg ie sh ie jeehine kl | ee cdl i Wap ry) ’ eAclseeid btn bad fn 5 Lae et ye ey “ie & 4 evr Lit ; V4 e Ar Naty hes et 2 lg Ltt ty C meaey Waits! a a N saat | 4 4 thre PARA MAL Ny CT Ee tates * niet 13 ry ni bib Doha tier 4g be repeeentd ai) et , ¢ Ue apse a) Aad pale Usd diead V4 TOUT! Hatred cs M3 94 riper yt ee its Veigavead Tere aly "4 yyy) Oe Hae tai SAG i it mati te ORDO agree, sly aly iietneatatenat rine ha Hy 1a iit siathe Nit ates yah 1) _ ty hte vb, may ity i. cet Sei eartt airitiiates wi tay sh + pe ye » waa say th An) i wah Shela bedl waded Di veal eam Petenae ay POOn Mr ee Srey “! aang Nie 44 + ei aYadhats Md 4 Aaa eat } Hi i aoe aie ry Rice +7 at a Mon rey nh) didiet ween NOME Ales |) aiPgrrd SA) oe eM bade) aL | fy i ¥) AE, PO] Picts ve ye Pt alten 4 TIME wed | 9d 9 Wane t ty aw dey Athan oh) iy eyagh Tray tritay Wy bia dea rela sete need t ymaid oe Ota ay atensse ia, ty bee Aero we be nent e 1) TE AL Corey eens ar (as ie bel alerstalerare Site HOF rine ai CPL SEL) sen Wa eeren! tee yy et wie LEM PU Ree TE | eipal Aa “waa een bt PAs cone ne Viale aide Ai darnay ae HH A Ahy Me hap “ oir , Reoren Npaty: ratte ate ie dbase fitelerw plait ya ys) naet Wve an 3 ater one ay ST a 40: fake ‘ Hit it a yi Os ehh PO ters Cem a \ PREEACE The greater portion of the material included in this study has been taken from a thesis of the same title, submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Entomology in the Graduate School of the University of Illinois, 1940. The original material has been revised, and several additions have been made. The author wishes to express his sincerest thanks to Professor W. P. Hayes, of the Department of Entomology, University of Illinois, under whose supervision this study was conducted. Professor Hayes suggested the problem and throughout the study has furthered its progress by his many helpful criticisms. He has given unstintedly of his time, and has also placed at the writer’s disposal his excellent personal collection of / Conotrachelus. It is with pleasure that the author names a new species, C. hayesi, in his honor. Much credit is due Mr. L. L. Buchanan, of the United States National Museum, who has given generously of his time to discuss with the writer the problems involved in the genus, and who has been of much assistance during the entire course of the study. Mr. Buchanan has informed the writer of several morphological characters of taxonomic value in the genus, has arranged for specimen loans from the National Museum, and has assisted the writer in innumerable ways. The writer takes pleasure in naming a new species, C. buchanani, in his honor. The author also wishes to express his appreciation to Dr. C. L. Met- calf and Dr. W. V. Balduf, of the Department of Entomology, Univet- sity of Illinois, for their interest and kind cooperation in this problem; to Dr. P. J. Darlington, Jr., Museum of Comparative Zoology, Cambridge, Massachusetts, for comparison of specimens with the J. L. Leconte types, and for the many courtesies which he extended to the writer during his visit in Cambridge; to Dr. E. C. Van Dyke, of the Department of Entomology, California Academy of Sciences, for comparison of spect- mens of Conotrachelus naso Lec. with the type of C. cinereus Van Dyke; to Dr. Z. P. Metcalf and Dr. T. B. Mitchell, of the Department of Zoology and Entomology, North Carolina State College, for the facilities which made it possible to revise the original manuscript; and to Mr. H. S. Barber, of the United States National Museum, for information concern- ing the nomenclature of the genus Conotrachelus. Only through the kind cooperation of numerous individuals were the necessary specimens procured for this study. To the following, the writer is indebted for specimen loans: Dr. H. H. Ross, Illinois State Natural History Survey; Dr. C. L. Fluke, University of Wisconsin ; Dr. H. E. Jaques, Iowa Wesleyan College; Dr. L. Haseman, University 6 ILLINOIS BIOLOGICAL MONOGRAPHS of Missouri; Dr. P. O. Ritcher, University of Kentucky; Mr. W. J. Gerhard, Field Museum of Natural History; Dr. C. E. Mickel, University of Minnesota; Mr. C. A. Frost, Framingham, Mass.; Dr. Marion E. Smith, Massachusetts State College; and Dr. C. S. Brimley, Division of Entomology, North Carolina Department of Agriculture. The writer also wishes to thank Dr. R. C. Smith, of Kansas State College, and Dr. Clay Lyle, of Mississippi State College, for their assist- ance in securing biological data. Raleigh, North Carolina Hares, Ill. LY. VI. CONTENTS . INTRODUCTION . REVIEW OF LITERATURE MATERIALS AND METHODS . A. The Removal, Study, and Preservation of the var Genitalia. Senn d Hires B. Measurements ae C. Studies of Collections and pone D. Organization of Distributional Data THE MorRPHOLOGICAL CHARACTERS OF TAXONOMIC IMPORTANCE A. The Body Rebs and Their Cra ae B. Color and Vestiture C. Characters for Sex Determination D. The Male Genitalia . NOMENCLATURE CLASSIFICATION Key to Groups , A. Group I (with Key to iSepcies). | C. juglandis Lec. . nenuphar (Hbst.) buchanani n. sp. . albicinctus Lec. . Ltowensis N. sp. . retentus (Say) . affints Boh. . . hicoriae n. sp. fallt Blatch. nivosus Lec. . seniculus Lec. . elegans (Say) . hayest n. sp. . aratus (Germ.) . . tibialis n. sp. Soro a Ore Cra. @ GN Oa 8 ILLINOIS BIOLOGICAL MONOGRAPHS VI. CLASSIFICATION (continued) B. Group II (with Key to Species). © . . 3 33m C. crataegi Walsh. . «1 4 ws 6 C. adspersus Lec. . =» . | . . «re C.naso.Léc:| 2... . . « ), «¢ 2 See C. carinifer Casey. . . ..,.. . -) ee C. posiicatus Bohs. .. .° + « |. « =e C. recessus (Casey) .. . . » = . .)7e C. geminaius Lec... . | +» 2) » os Snel C. cribricolus (Say) . . .. =. . §. 7) eee C. Group III (with Key to.Species) ._.. . 92 aeeumabe C. tuberosus’Lec. ~.2 . «5 3s & = « ne C.andglyptiicus (Say). .\ . .’ . 2 (Seen C. leucophaeatus Fahr. . °°. .' . ©. | - ees D. Group lV (with Key to Species). . ©. 3: )ieuememeleees C. fissungeuis Lec... . «=... . & + 5 C. evinaceus Lec.- 2... + « “5 Qe VII. ADDENDUM: Conotrachelus carolinensis n.sp. . . . . 136 ” WIT SUMMARY . 930 4-5.) e'\ 04 5 2) Ve ee DX. (GLOSSARY... oe kh ON a ae a X. IaTERATURE CITED -- .‘.-. . fo. 4% ' 29) 300 Rees PUATES ~. «- <0 68 4 Dye 2 2A ee INTRODUCTION The genus Conotrachelus Dejean embraces over 930 known species, all of which are confined to the Americas. The majority of these species occur in South and Central America, 54 species being known from the United States and Canada. In spite of the relatively large number of species in this region, little taxonomical or morphological work has been done on the genus other than that included in general considerations of the Rhynchophora. Biological data have been accumulated on many of the species, but, as will be pointed out later, the significance of some of these data is questionable because of specific confusion. Consequently, a taxonomic revision of the genus would seem to be of definite value. The investigations reported here have a threefold purpose; first, to prepare workable keys to, and descriptions of, the species of Conotra- chelus occurring in Illinois and the surrounding states of Wisconsin, Iowa, Missouri, Kentucky, and Indiana; second, to study the morphology of the male genitalia and determine their taxonomic significance; and third, to evaluate the morphological characters previously used in the classification of this genus, and, if possible, to indicate additional ones. The majority of the species found in this middlewestern area are present over the eastern half of the United States, and the classification herein will, in general, apply to this eastern area. Pi. REVIEW OR LYEERATURE The taxonomic literature on the genus Conotrachelus has been confined to considerations in comprehensive works on the Rhynchophora and to descriptions of new species. Dejean (1835) erected the genus Conotrachelus, but merely listed the species included. Schonherr (1837) was the first to bring together in a descriptive manner the known species of Conotrachelus. Of the sixty- five species discussed in Schonherr’s Genera et Species Curculionidum, twelve occurred in the United States, and the remainder were from South or Central America. A key was given by Schonherr in which the final designation was to groups of species instead of to one species. The genus and many of the species were described in detail, but the majority of the descriptions were by Boheman and Fahreus, Sch6nherr having dis- cussed only the generic characteristics. Most of the species were accredited to prior workers, but subsequent study has shown that many of these were nomina nuda; consequently, many new species were erected unknowingly. In 1845 Schénherr published another work on this genus, including at that time 106 species, of which thirteen were from the United States. 10 ILLINOIS BIOLOGICAL MONOGRAPHS Leconte (1876) was the first American author to discuss the genus Conotrachelus. He separated it into four divisions, Division I consisting of parts A and B. In the appendix of the same publication Leconte amended his Division I, subdividing part B into two sections. The characters used to erect these groups are similar, except for modifications, to those used by the writer (p. 40). Leconte discussed twenty-four species in the text of his work, eleven of which were new. In the ap- pendix, he described one other new species and stated that plagiatus n. sp. (p. 233) was a synonym of nivosus n. sp. (p. 229). The majority of the remaining thirteen species were redescribed, but several of them, such as anaglypticus (Say) and leucophaeatus Fahr., were only briefly men- tioned. Leconte did not give any biological data, his discussion being confined to taxonomy and nomenclature. Champion (1904) published the most comprehensive work on this genus, but his study, with the exception of four species, posticatus Boh., leucophaeatus Fahr., anaglypticus (Say), and serpentinus (Klug), was mainly concerned with the Central American fauna. Champion discussed 188 species, the majority of which were new. The characters of pre- viously described species were briefly mentioned and each new species was fully described. The descriptions and discussions of the species were in numerous instances supplemented by figures, many of which were colored. The type of key employed was similar to that of Schonherr, the final designation being to a group of species. Champion’s key, how- ever, was condensed in a unit instead of being scattered through the text as was the case with Schonherr’s. Blatchley and Leng (1916) considered those species of Conotrachelus east of the Mississippi, treating twenty-eight, one of which was new. These authors followed Leconte’s subdivisions of the genus, except that they listed them as Groups I to VI. All the species were redescribed and biological and distributional data were given. The most recent treatment of the genus is that by Mutchler and Weiss (1925).* These workers brought together the available biological data on the sixteen species occurring in New Jersey and discussed briefly the genus and these species, including a descriptive key to the latter. This paper is of much value for its biological discussions. The six previously mentioned treatments are the only comprehensive works pertaining to the entire genus. Other references, briefly discussed below, are limited to descriptions of new species or to one section of the genus. *Dr. T. D. A. Cockerell, in Science, Vol. 92, No. 2397, December 6, 1940, reviews a British Museum Publication by K. Fiedler, entitled, ‘‘Monograph of the South American Weevils of the Genus Conotrachelus,”’ February, 1940, 365 pages. According to the reviewer, this mono- graph treats approximately 600 species, of which 416 are new. It is well illustrated and is published in German. The writer, as yet, has been unable to examine a copy of this monograph; consequently, it is not mentioned in the review of literature. GENUS CONOTRACHELUS DEJEAN—SCHOOF 11 The earliest description of a species of Conotrachelus was that of nenuphar by Herbst (1797).* Germar, another European worker, de- scribed aratus in 1824. Say (1831), the first American author accredited with species of Conotrachelus, described retentus, cribricollis, anaglyp- ticus, and elegans. Walsh (1864), Leconte (1878), and Casey (1892, 1910) also described new species. Schaeffer (1904, 1906) published descriptions of five new species and included in the 1906 paper a key to all the known species of Leconte’s Division 1-A. Recent describers of new North American species have been Fall (1907, 1913, 1917, 1929), Blatchley (1917), and Van Dyke (1930). Buchanan (1937) published the synonymy of C. atokanus Fall and Loceptes recessus Casey. The genus Conotrachelus and its species have also been considered in numerous catalogues. Dejean (1835, 1837) in his catalogue listed seventy- one specific names, of which sixty-seven were nomina nuda. Henshaw (1885, 1895) listed twenty-eight species north of Mexico in 1885, and in his Third Supplement (1895) added six more. Leng (1920) listed forty-eight species north of Mexico, and in his Second Supplement (1933) increased the total to fifty-three. The most recent catalogue is that by Hustache (1936), in the Coleopterorum Catalogus of Junk and Schenkling, in which fifty-four North American species are listed. While Henshaw and Leng considered only the North American species and their synonymy, the Coleopterorum Catalogus deals with all species of Conotrachelus and includes references to biological data as well. Several names are shown to be preoccupied, and new ones are substituted. The Leng catalogue and supplements, however, are the most reliable sources for references to original descriptions and distributional data. In the Coleopterorum Catalogus, the distribution of certain American species known from only one locality is frequently given as “Etats Unis.” Some Cuban species also are erroneously reported as occurring in the United States. This catalogue, however, is preferred for biological references. Most of the species mentioned in this review of literature, excepting those treated by Leconte (1876) and Blatchley and Leng (1916), are indigenous to the Gulf Coast States and the southwestern area. Conse- quently, this treatment of the species in the midwestern area will be principally concerned with those species discussed by Leconte (1876) and Blatchley and Leng (1916). Further references to these two works will be found under the discussions of the individual species. The morphological literature is discussed under the section on morphology, and the nomenclatural references are included in the section on nomenclature. *All species before 1835 were placed in allied genera, as the genus Conotrachelus was not erected until that date. 12 ILLINOIS BIOLOGICAL MONOGRAPHS Ill. MATERIALS ;:AND METHODS A. THE REMOVAL, STUDY, AND PRESERVATION OF THE MALE GENITALIA The initial step in the dissection of the male genitalia is the removal of the abdomen, since with museum specimens it is very difficult, if not impossible, to dissect out the genitalia with the abdomen in situ. Before this is attempted, however, the specimen should be relaxed, as it is desirable that the specimen be fully pliable before being handled. For manipulation, the insect, when unpinned is best held between the thumb and forefinger. The fingers possess a certain amount of pliability which cannot be obtained with forceps; the latter frequently slip and cause the insect to be violently expelled. With the specimen in place, a sharply pointed, flattened needle is gradually inserted between the abdomen and the metacoxa. When the needle enters the coxal cavity it is slowly turned so that the flattened point acts as a lever forcing the abdomen to separate from the metacoxae and the metasternum. The needle is then moved medially to sever the connecting tissues and to further separate the ab- domen from the metasternum. In some instances only one manipulation of the dissecting needle is necessary ; in others several different insertions may be required. While removing the abdomen the specimen should be held firmly so that the elytra do not become disengaged; otherwise they may become permanently “sprung.” The removed abdomen is placed in a cold solution of concentrated potassium hydroxide, the period of immersion in this solution varying with the specimen, the larger ones requiring approximately one hour, the smaller ones thirty minutes. It is best to soak the abdomen in potassium hydroxide only until the muscles have softened, rather than until they have broken down completely, since the length of time necessary for muscular disintegration may lead to undesirable softening effects upon the genitalia. After removal from the potassium hydroxide solution, the abdomen is washed in water and placed in a few drops of water upon a slide. With the dorsal surface of the abdomen upwards, a needle is placed basally within the body cavity to hold the structure in position. When secure, a lengthwise incision is made along each side of the dorsum at its line of junction with the pleural region. The latter is heavily sclero- tized, while the first six terga are membranous. The seventh and eighth terga, however, are sclerotized and fit tightly against the pleura (see Fig. 10), so progress in cutting here is slow and difficult. Care must be taken at these points to keep the cutting instrument as near to the pleura as possible, since the male genitalia lie close to the lateral walls of the seventh and eighth terga. When the incisions have been completed, the dorsum, genitalia, and eighth sternum may be removed in mass from GENUS CONOTRACHELUS DEJEAN—SCHOOF 13 their normal position. Muscles and intestine are then removed and the genitalia may be easily seen attached to the eighth segment. Since they are fastened to the body wall by a membrane (Fig. 8, Ist connecting membrane ), this must be severed both dorsally and ventrally to release the genitalia. Once the membrane is cut the genitalia are free and can be removed to a storage vial. The technique discussed above was the one usually employed, but in many cases digressions from it were necessarily made, depending on the condition of the specimen to be dissected. Sometimes it was not necessary to remove the dorsum completely, but merely to sever it half- way and then by pressure upon the genitalia to force them outward. Occasionally potassium hydroxide was not employed, especially with freshly-emerged specimens where the genitalia already were soft. Other variations in the method occurred repeatedly because of the differences in the age, size, and condition of the specimens. After the genitalia have been removed, the dorsum is replaced on the sclerotized sterna and pleura of the abdomen. The entire abdomen is then allowed to dry, and the dorsum upon drying adheres firmly to the sterna and pleura. Following this, the abdomen with its ventral surface upwards is fastened by an adhesive to the card point bearing the specimen. In this position the punctation of the abdominal sterna is readily acces- sible for study. The abdomen may be replaced in the specimen, but this is difficult and damage to the specimen may result. Such replaced abdomens cannot be fastened as securely as they can be on card points and they may later drop off. The genitalia were temporarily stored in vials in a solution of 70% ethyl alcohol or in a three-to-one mixture of 70% alcohol and glycerine. The former was preferred since it did not show the tendency to ‘“‘creep”’ up the sides of the vials as did the mixture of alcohol and glycerine. Genitalia to be studied comparatively were placed in glycerine-filled depression slides which had perpendicular wells. For drawing and detailed study of the genitalia a syracuse watch glass half-filled with paraffin was used. A layer of glycerine or alcohol was poured over the paraffin and the genitalia then fastened in position by means of a minuten nadeln. It was only by this method that the genitalia could be securely fastened in position. Cotton, sand, and glass chips were unsatisfactory for this pur- pose. Light reflected up through the paraffin provided a satisfactory background. Glycerine invariably worked down under the paraffin and loosened it, and new study dishes had to be prepared every month. For permanent preservation of the genitalia the following method was employed: a cork disc 4.” thick and 10 mm. in diameter, with a hole 4 mm. in diameter slightly off center, was attached to the insect pin bear- ing the specimen. A 7 mm. circular coverslip was then fastened to the 14 ILLINOIS BIOLOGICAL MONOGRAPHS ventral surface of the disc by means of Canada balsam. If desired the coverslip could be fastened to the disc before the latter was attached to the pin. A thin layer of balsam was next placed in the resultant cavity, and the genitalia arranged in this layer. Previous to this arrangement, the genitalia had been immersed in absolute alcohol from one to five minutes. The disc was then set aside for 24-48 hours until the balsam hardened. This firmly fixed the genitalia in position so that when the remainder of the balsam was added the genitalia did not float about. The surface ten- sion of the thin layer kept the genitalia in position until the hardening occurred. Genitalia placed directly in a thick layer of balsam would rarely stay in position even though the disc was kept horizontal. At the end of the hardening period the entire cavity was filled with balsam and another coverslip fitted over the dorsal surface of the disc. The mount was then gently heated to drive off any air bubbles, after which it was stored in a horizontal position to prevent the genitalia from slipping to one side of the disc. If the mount was tilted excessively, the genitalia would shift their position even though the balsam had been preliminarily hardened. After the balsam hardened entirely it was possible to tilt the disc in any direction, at least temporarily, without the genitalia moving. Occasionally frass from the sides of the hole would get into the balsam, but this diffi- culty was overcome by previously soaking the cork discs in waste alcohol. This type of mount permits direct examination of the genitalia both dorsally and ventrally. If the genitalia have been slightly tilted so that they le on their lateral surface, the hole in the disc is still wide enough to permit examination of both dorsal and ventral surfaces. This method of mounting was satisfactory for the genitalia of Conotrachelus. A some- what similar type was used by Mitchell (1936) for the preservation of the genitalia of Megachile (Hymenoptera). These mounts allow sufficient observation for taxonomic comparisons, but if detailed study is necessary, soaking the disc in xylene will dissolve the balsam and permit the removal of the genitalia. Several dry mounts of genitalia were made, but with slightly softened genitalia and with genitalia that possessed a narrow apical process this method led to distortion of the specimen. The small vial-glycerine tech- nique likewise could have been employed, but the balsam-filled cell mounts are easier to observe and more attractive in appearance. A discussion of the technique involved in the eversion of the endo- phallus of the male genitalia is given on page 32. B. MEASUREMENTS In measuring the various areas of the insect body and the male genitalia, the following system was employed: the length of the insect GENUS CONOTRACHELUS DEJEAN—SCHOOF 15 was calculated from the anterior margin of the eye to the apex of the elytra, while that of the beak was a straight line from the apex to the ventral angle of junction between the beak and the eye. The length of the prothorax was computed dorsally at the midline, while the width was taken at the broadest point dorsally. The basal area of the elytra up to and including the humeri was the criterion for the elytral width, while the length of the elytra was calculated from the basal margin to the apex at the line of junction of the wing covers. The length of the aedeagus was measured dorsally from the basal median point to the apical median point, while the width was calculated only at the base. If the lateral plates of the aedeagus narrowly extended beyond the major portion of the base, as in naso Lec. (Fig. 59), the width was taken at the place where the narrow extensions of these plates joined the major basal portion of the aedeagus. The aedeagal struts were measured from their tips to their junction with the aedeagus. C. STUDIES OF COLLECTIONS AND TYPES In order to get representations of the Conotrachelus fauna in the states included in this study, loans were requested of the universities and scientific societies in those states. In addition, requests were also sent to museums and to private collectors outside the midwestern area. The institutions and individuals from whom loans were secured are listed below. Other collections studied but not secured in loans are given; these are marked by an asterisk. *Blanchard Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. *Bowditch Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. *Casey, Greene, Soltau, and Wickham Collections, United States National Museum, Washington, D. C. *Dietz Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. *Eddy Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. *Fall Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. Field Museum of Natural History, Chicago, Illinois. Frost Collection, Framingham, Massachusetts. Hayes Collection, Urbana, Illinois. Illinois State Natural History Survey, Urbana, Illinois. Iowa Insect Survey Collection, Iowa Wesleyan College, Mt. Pleasant, Lowa. *Leconte Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. *Liebeck Collection, Museum of Comparative Zoology, Cambridge, Massachusetts. Massachusetts State College, Amherst, Massachusetts. Nason Collection, Department of Entomology, University of Illinois, Urbana, Illinois. *North Carolina State Department of Agriculture Collection, Raleigh, North Carolina. University of Kentucky, Lexington, Kentucky. University of Minnesota, St. Paul, Minnesota. University of Missouri, Columbia, Missouri. University of Wisconsin, Madison, Wisconsin. 16 ILLINOIS BIOLOGICAL MONOGRAPHS To be certain of specific identities, the type specimens of Leconte, Walsh, and Fall, at the Museum of Comparative Zoology, Cambridge, Massachusetts, and those of Schaeffer and Casey at the United States National Museum, Washington, D. C., were examined. In some cases types were inaccessible, and in these instances careful checking of the descriptions and examination of specimens identified as these species by various coleopterous specialists were the criteria employed. D. ORGANIZATION OF DISTRIBUTIONAL DATA In the distributional data, all locality records are from specimens actually seen by the writer. No previous state records from catalogues or publications have been included because of the possibility that misidenti- fications may have occurred. In the consideration of holotypes, allotypes, paratypes, lectotypes, etc., the present location of the specimen involved is indicated by the capital letters enclosed in parenthesis at the end of the statement. The key to these abbreviations is as follows: (MCZ)...........Museum of Comparative Zoology, Cambridge, Massachusetts. CUISININDY soc dacte United States National Museum, Washington, D. C. CUSINIBIS))s 000506 Illinois State Natural History Survey, Urbana, Illinois. (CUWAPRIED Sa scasn eee Private Collection of Professor W. P. Hayes, Department of Entomology, University of Illinois, Urbana, Illinois. CMS @)- cy, Massachusetts State College, Amherst, Massachusetts. CRO) Reece ose Purdue University, Lafayette, Indiana. GIS@) ee ahae. Iowa Insect Survey Collection, Iowa Wesleyan, Mt. Pleasant, Iowa. (CAI) eBay ae cee Private Collection of Mr. C. A. Frost, Framingham, Massa- chusetts. (IMIG) Reeve ccra 2s Nar: University of Missouri, Columbia, Missouri. CEIBS) Rees tes Private Collection of H. F. Schoof, North Carolina State College, Raleigh, N. C. (QUIUIDIS)) sob oan0ce University of Illinois, Department of Entomology, Urbana, Illinois. IV. THE MORPHOLOGICAL CHARACTERS OF TAXONOMIC IMPORTANCE The following discussion of the important morphological characters used in the taxonomy of Conotrachelus is based only on the species included in this study. The discussion is divided into four sections: (A) the body regions and their appendages, (B) coloration and vestiture, (C) char- acters for sex determination, and (D) the male genitalia. GENUS CONOTRACHELUS DEJEAN—SCHOOF 17 A. THE Bopy REGIONS AND THEIR APPENDAGES In the head region the characteristics of the beak are of chief im- portance. The head capsule in the different species is similar, usually being densely punctured, with the punctures smaller than those of the thorax. The beak, on the other hand, shows variations not only in the different species but also in the sexes. The most reliable specific character of the beak is its length and form, either of which varies greatly in many of the species. By means of the length and slenderness of the beak it is possible to distinguish the females of both elegans (Say) (Fig. 39) and hayesi n. sp. (Fig. 40) from the female of aratus (Germ.) (Fig. 41). In the female of naso Lec. the beak is extremely long, reaching the abdomen, and this character alone sepa- rates it from the female of posticatus Boh. where the beak only attains the mesocoxae. The curvature of the beak sometimes is more pronounced in one species than in another, as in nenuphar (Hbst.) and hayesi (Figs. 35 and 40). In some species, especially those of Group III, the curvature is slight until near the antennal insertion, where it is suddenly bent inwards. Another beak characteristic of importance is the ratio of the distance between the lateral apical emargination of the beak and the anterior margin of the ball of the antennal scape to the distance between the dorsal and ventral surfaces of the beak at the position of the antennal insertion. (See Fig. 105.) This is especially evident in species whose beaks differ in stoutness, since this proportional character affords a method by which the terms stout and slender can be given a more concrete basis. The sulci of the beak are of secondary importance in specific identifi- cation, being used more in sex differentiation. The beak usually has three lateral sulci on each side between the base and antennal insertion. These sulci have been called the upper sulcus, the median sulcus, and the lower sulcus, the latter being that sulcus nearest to the antenna. Occasionally the lower sulcus is divided into two as in tuberosus Lec. These sulci have been used in descriptions in the past, the usual reference being “strongly sulcate or striate,” “deeply striate,” or “feebly striate.’’ These statements, however, are too inflexible, and many times fit only certain individuals of a species. Frequently the sulci are distinct in one speci- men and feeble in another, they may vary in distinction on the different sides of the beak, or the basal half of a sulcus may be distinct, the apical half obscure. Consequently one must be cautious in diagnosing the type of the sulci; otherwise the characterization may lead to confusion. These sulci sometimes are not present as in adspersus Lec., and in this case their absence is an excellent diagnostic character. If the sulci are present, distinction between species based on the relative development of the sulci is not altogether reliable. 18 ILLINOIS BIOLOGICAL MONOGRAPHS Other sculptural features of the beak such as punctation and carina- tion are more significant for sex differentiation than for specific dis- tinction. The prominence of a dorsal median carina is sometimes largely dependent on the development of the uppermost sulci. The position of the antennal insertion on the beak is primarily a sex characteristic, but the relative length of the funicular segments of the antennae is sometimes of specific interest. In a majority of the species the first two segments are subequal in length and each is longer than any of the others. The apical segments generally tend to become successively globose, and the first, while subequal in length to the second, is frequently much stouter. The most notable exceptions to the above pattern are adspersus Lec. and recessus (Csy.) where the first funicular segment is approximately as long as the next two combined. The characters of the prothoracic region are principally based on the sculpture of the dorsal and lateral areas. These areas show differences in punctation, carination, and tuberculation in the various species. The punctation in all cases is dense and varies from reticulate to cribrate. It is difficult to set up distinctions based on the size and form of the punctures, since many of the species have punctations which are quite similar; and while the differences are evident with the insects in juxta- position, it is quite difficult to describe them so that the user of the key may identify a single specimen. The species geminatus Lec. and cribri- collis (Say), however, differ so greatly in their punctation that they can easily be separated or identified by its use. The prothorax is sometimes longitudinally carinate on its median, dorsal surface, and this character has been used much in the past for specific distinction. In some species such as seniculus Lec., naso Lec., leucophaeatus Fahr., and posticatus Boh., it is a stable characteristic, but in others like affinis Boh. it is unreliable. In affinis Boh., nenuphar (Hbst.), and buchanani n. sp. the carina may be distinct on the apical half in some individuals; in others it may be lacking. Until a long series of specimens is examined, the relative distinctness of a prothoracic carina cannot be considered a certainty. Tubercles are also present on the prothorax, particularly in Group I. Usually there are two discal pairs, one transversely at the middle, the other between the median pair and the basal margin. The prominence of these protuberances, however, like the prothoracic carina, is subject to much variation. Consequently, it cannot be used for specific distinction. Nevertheless, one western species not considered in this study, tubercu- licollis Schffr., has such large and prominent tubercles that they are valid specific characters. The presence of a median furrow on the prothorax is one of the GENUS CONOTRACHELUS DEJEAN—SCHOOF 19 characters used to separate Group III from Groups I and II. It may vary in prominence, but it is always evident. The relative length and width of the prothorax is an aid in descrip- tion, but not for specific identification. In all the species studied it was wider than long, but the ratio between the two dimensions was variable. Ventrally, the prothorax is always provided with a groove for the reception of the beak. This character is of importance in subfamily and tribal classification. The mesothorax has two structures of importance, the mesoscutellum and the mesosternum. The mesosternum has been used by Leconte (1876) and Blatchley and Leng (1916) in separating geminatus Lec. and cribricollis (Say) from posticatus Boh., the structure being considered prominent in the latter, and not prominent and sloping downwardly in the other two species. This characterization is ambiguous, however, since the mesosternum of cribricollis (Say) can be considered prominent and it definitely does not slope anteriorly as is true in geminatus Lec. The writer has used the same structure in the present classification, but has placed the emphasis on the basal angles. The mesoscutellum is a new taxonomic character in Conotrachelus which was first noticed in working with albicinctus Lec. and buchanani n. sp. These two species, as will be noted in the key (p. 41), are separated by this character; the mesoscutellum in albicinctus Lec., when viewed from the lateral aspect, is abruptly declivent basally, while that of buchanani n. sp. slopes gradually toward the base (Figs. 29 and 30). The same character has also been used to distinguish iowensis n. sp. from nenuphar (Hbst.). Before this character is employed to differentiate other species, however, it should be checked in a number of specimens, since the shape of the mesoscutellum in some species is not always constant. The metathorax is chiefly of importance in sex determination as explained on page 24. The thoracic appendages are of much significance both as characters for sex determination and as specific indicators. With the elytra, the costate alternate intervals have been emphasized a great deal by Leconte (1876), Blatchley and Leng (1916), and Mutchler and Weiss (1925), and in several instances it appears that too much importance was placed on them. In those species where the costae of intervals 3 and 5 are inter- rupted to form abrupt elevations, as in nenuphar (Hbst.), albicinctus Lec., and others, the interruptions are distinct and constant in occur- rence. In species, however, where those costal elevations are feeble, as in elegans (Say) and others, the interruptions occurring in the costa of interval 5 are feeble and extremely variable. For example: elegans (Say) 20 ILLINOIS BIOLOGICAL MONOGRAPHS is described as having the costa of interval 3 twice interrupted and that of interval 5 “not interrupted posteriorly at the postmedian band,” while aratus (Germ.) has the costa of interval 3 twice interrupted and that of interval 5 “not broken anteriorly.” As these two species have been diff- cult to separate the obvious difference in the form of the costa of interval 5 has been logically seized upon as a specific character. Mutchler and Weiss (1925) incorporated this costal difference into their descriptive key of this genus. When various individuals of both of these species are examined, however, it is revealed that the costa of interval 5 in elegans (Say) is complete or once interrupted posteriorly, or occasionally feebly interrupted anteriorly, while that of aratus (Germ.) is usually twice interrupted, sometimes once anteriorly. Consequently, a distinction be- tween the two species on the basis of the interruptions of the elytral costal of interval 5 is valueless. The writer has also found that the elytral costa of interval 5 in numerous other species of Group I varies in form to the same extent as it does in the previously mentioned species. Too much weight, therefore, should not be placed on the interruptions of the costa of interval 5 unless the character has been found constant in a long series of specimens. In five specimens of hayesi n. sp. the costa of interval 5 is only interrupted anteriorly, but the writer feels that in all probability future specimens will show variations. The interruptions of the costa of interval 3 in contrast to those of the interval 5 are two in number and constant in occurrence in Group I, except in fall Blatch., nivosus Lec., and rarely elegans (Say). In Groups II-IV the intervals are sometimes non-costate, and when they are costate two strong interruptions of the costa of interval 3 occur only in tuberosus Lec.. The elytral costae in these other groups are more stable in appear- ance than those of Group I. Leconte (1876) stated that the elytral costae in nenuphar (Hbst.) are much more abruptly interrupted and the posterior elevations more prominent than in either juglandis Lec. or albicinctus Lec. This study has showed that while this is true in some instances, the reverse also occurs and, consequently, the relative abruptness and prominence of costal elevations are not to be relied upon. In concluding this discussion of the elytral costae, it may be said that they are of distinct specific importance, but thorough observation should be made for any variations that may occur, before setting up a standard type for a species. Likewise, it should be kept in mind when identifying a specimen that a disagreement with the costal interruptions specified in the description should not be overemphasized if the other characters are in full agreement. The humeri, serial punctures, relative length and width, and out- line of the elytra are of special value in some species (e.g., humeri in GENUS CONOTRACHELUS DEJEAN—SCHOOF 21 crataegi Walsh), but in general they are of less importance than the costae. The legs are of much taxonomic importance. The number of teeth on the apical ventral area of the femora has been frequently used in classi- fication. There are either one or two teeth present, the distal tooth sometimes being more of a denticle. These teeth usually are excellent characters, but a few intermediary species occur between the one- and two-toothed groups and confusion sometimes occurs. In those cases it has been necessary to insert a second character to clarify the situation. Thus, in tibialis n. sp. the male usually has the proximal tooth obliterated, and on this basis should go into the one-toothed group. Other characters and habitus, however, as well as the fact that the female has two distinct femoral teeth, place the species in the two-toothed group. Consequently, a tibial character of the male has been inserted in the key to prevent misidentification. The punctation of the legs has been studied, but it does not offer much possibility for taxonomic purposes, since it is similar in the majority of the species. The form of the tibiae, however, is of importance in some species, as in the male of tibialis n. sp. where the protibiae exhibit a remarkable distal concavity (Fig. 3la) in contrast to the normal protibiae found in all other species of Conotrachelus (Fig. 31b). Likewise anaglypticus (Say) shows a distinct concavity at the distal end of the metatibiae in the male (Fig. 32a) usually not found in other species. The most reliable leg character revealed by this study is the shape of the metauncus, or metatibial spine (Fig. 20). Before discussing the taxonomic value of this character, it is necessary to consider the morphology of the structure. The term uncus (pl. unci) is taken from Marshall (1932) who states that it is a stout, curved hook developed from the outer apical angle of the tibia. Another spine developed from the inner angle of the tibia is called the mucro (pl. mucrones). Usually each of these types of spine is distinct, but the uncus tends to shift inwards, so that in some cases it appears to rise from the inner angle and resembles a mucro. This shifting occurs in Conotrachelus as will be seen in Fig. 20 where both an uncus and a mucro are present. The mucro appears to be absent in the male in many cases, but it is present in the female, although often obscured by a tuft of setae. The uncus, on the other hand, is always evident in both sexes and is of value both specifically and for sex determination. The unci in the females are always single, never dentate, but in the male the metaunci are frequently dentate. Con- sequently, in many of the species the sexes can easily be determined by an examination of the metaunci. Therefore, in many cases where a distinguishing character between species has been lacking, it has been found possible to differentiate the species by considering the sexes 22 ILLINOIS BIOLOGICAL MONOGRAPHS separately. Thus in elegans (Say) and aratus (Germ.) where a great deal of specific confusion has arisen in the past, it was found that the males of the two species are distinct, in that those of elegans (Say) have both meso- and metaunci dentate while in avatus (Germ.) only the metaunci are dentate (Figs. 25 and 26). The females of the two species are dis- tinguished by differences in the length, stoutness, and form of their beaks (Figs. 39 and 41). The shape of the dentate metauncus is sometimes of value in sepa- rating the males of species, as in the case of affinis Boh. and hicoriae n. sp. (Figs. 23 and 24). Species do not always show differences in the form of the denticle on the metauncus, and this is indicative of affinities (Figs. 26, 27, and 28). The shape of the metauncus may possibly vary in the same species (Fig. 25). The chief taxonomic feature of the abdomen is its punctation, which in this genus varies from sparse to dense and from fine to coarse. It is an excellent indicator in those cases where the differences in the density and distinctness of the punctation are extreme, such as in the separation of retentus (Say), affinis Boh., and hicoriae n. sp. from elegans (Say), aratus (Germ.), tibialis n. sp., and others. Too much stress should not be placed on minor variations, however, since these may occur within the same species when enough specimens are examined. The chief diffi- culty with the use of abdominal punctation, as well as that of other regions, is the use of relative terms which apparently must be employed to indicate the density and coarseness of the punctures. Terms such as “sparse” and “dense” are significant, but there is a wide range between these extremes which cannot be definitely characterized. In this paper, “dense punctation” means one similar to that shown in Fig. 33, while Fig. 34 illustrates a “moderately dense” punctation in the top half of the illustration and one slightly greater than moderate in the bottom half. The presence of a few widely scattered punctures is termed “sparsely punctured.” The writer has attempted to limit the use of abdominal punctation to the specific descriptions unless the differences have been exceptionally distinct. The coarseness of punctures varies even on the same segment, as will be seen in Fig. 34, and the range between a fine and a coarse puncture is much greater than that which occurs between the extremes of density. A definite standard to refer to a “coarse,” “fine,” or “semi-coarse”’ puncture could not be devised because the scale would necessarily vary with the size of the species. The coarseness of punctures, consequently, has not been employed in the keys unless the distinction was obvious. In the descriptions, both density and coarseness of punctures have been used. The number and type of punctures frequently vary on the different sterna, and such comparisons appear to be of distinct value in GENUS CONOTRACHELUS DEJEAN—SCHOOF 23 descriptions. The fifth abdominal sternum* frequently has a tubercle on both sides of the middle on the apical third, but the prominence of these tubercles is variable and the character is not reliable (see page 90). B. CoLork AND VESTITURE In the genus Conotrachelus as in many other groups, coloration is usually an unreliable character. Freshly emerged specimens naturally have a lighter color than those in which the pigment has been fully developed. This is particularly evident in those species of Conotrachelus that have been bred from nuts, such as retentus (Say), affinis Boh., and hicoriae n. sp. Specimens collected in nature are much darker and at first glance would appear to be different from reared specimens. In a few cases, however, color is of importance, such as in nenuphar (Hbst.) and 1owensis n. sp. where intense blackish areas on the elytra are characteristic of the species. In most of the species, the described piceous color may vary from black to red. Consequently, complete agreement between the color pattern of the specimen and that given in the description is some- times lacking. ; The type, density, and color of the vestiture are all of taxonomic importance as may be seen in the keys. The vestiture is usually com- posed of elongate, recumbent setae varying in color from white to a rusty red. These setae may be replaced by true scales, as in recessus (Csy.), or they may resemble scales to such an extent that they are termed “‘scale-like setae,’ as in adspersus Lec. Occasionally the pro- thoracic punctures and the elytral intervals bear, in addition to the recumbent setae, prominent suberect and erect setae, as in cribricollis (Say) and erinaceus Lec. The variations that occur in the type of setae present are innumerable, but the above are the principal forms. The relative densities of the setae or scales in the different species are of much importance when these relations can be expressed so they are clearly evident to the user of the key who has only one specimen on hand. Only in those cases where differences in the density of the setae or scales are extreme are such characters used in the keys, as in couplet 1 of the Group IV key. In many of the species the setae are scattered about with small condensations here and there, but in Group I the species usually have a definite, postmedian condensation which is of use taxo- nomically both by its distinctness and by the color of the setae composing it (couplets 4, 5, and 7 of the Group I key). The color of the setae varies considerably in the same species, but *The so-called fifth sternum is actually the seventh, since the first two abdominal sterna make up the posterior part of the metacoxal cavities and are not visible as sterna. The first visible abdominal sternum therefore is the true third. For taxonomic purposes and to avoid confusion, however, the true third sternum is considered the first ventral segment and the succeeding sterna are named accordingly. 24 ILLINOIS BIOLOGICAL MONOGRAPHS there are several species in which the setal color is almost always constant in certain areas, such as in the postmedian bands of buchanani n. sp. and albicinctus Lec., and in the oblique, elytral bar of anaglypticus (Say). The examples of the taxonomic value of the vestiture could be further enumerated, but a perusal of the keys and the descriptions, particularly the special characters, will indicate in a much better way its significance. The one disadvantage in its use is that specimens occasionally have their vestiture badly rubbed. C. CHARACTERS FOR SEX DETERMINATION The sexes of all the species of Conotrachelus may be differentiated by the presence of an additional visible abdominal tergum in the male. Thus it will be seen in Fig. 10 (male) that the eighth tergum is distinctly evident, while in Fig. 12 (female) it is wholly concealed beneath the seventh tergum (shown by dash line). This sex character in Cono- trachelus was discussed by Thomson (1932) for the sexes of nenuphar (Hbst.). The only possible disadvantage in the use of this character for the determination of the sexes is that it necessitates the disengagement of the elytra, but this is of little consequence when the sex of a specimen is an essential datum. There are several other characters useful in sex determination, but none of these are common to the entire genus. Instead, they seem to occur at random among the different species. The first of these char- acters is the presence of dentate metaunci in the males of certain species. As the unci of all females are non-dentate, this character is a reliable one. It is found in some species of all the groups except Group III. In Group I dentate metaunci are more common than in the other groups, being found in juglandis Lec., nenuphar (Hbst.), retentus (Say), affinis Boh., hicoriae n. sp., elegans (Say), hayesi n. sp., tibialis n. sp., and aratus (Germ.). In Group IT dentate metaunci occur in the males of naso Lec., carinifer Csy., and posticatus Boh., and possibly in cribricollis (Say). In Group IV erinaceus Lec. is the only species with this character. The dentate metauncus of nenuphar (Hbst.) was not noticed by Thomson (1932), although he did mention the extra large size of that uncus in comparison to the unci of the pro- and mesotibiae. The second of the secondary sex characters is the presence in the males of metasternal grooves extending from the posterior border of the mesocoxae to the anterior rim of the metacoxae (Fig. 19). This char- acter is confined to Group I, although not present in all of the species. C. juglandis Lec., nenuphar (Hbst.), albicinctus Lec., retentus (Say), elegans (Say), aratus (Germ.), and buchanani n. sp. possess these grooves, which are particularly distinct in the first three named species. GENUS CONOTRACHELUS DEJEAN—SCHOOF 25 They are frequently feeble in retentus (Say), elegans (Say), and buchanani n. sp. The third character is one commonly observed in Rhynchophora, in which the male has a shorter beak than the female. This is true in a number of species of Conotrachelus, but in many instances both sexes must be available before the difference can be seen. In naso Lec., hayesi n. sp., and adspersus Lec. the sexes may easily be distinguished without such recourse, since the difference in the length of the beak in the two sexes is pronounced (Figs. 37 and 40). Another use of the beak in sex differentiation is found in its sculpture, which is generally more distinct in the male than in the female. In the males the lateral sulci extend from the base to near the antennal inser- tion, the dorsal carina is acute, and the punctation of the dorsal surface distad of the antennal insertion is dense, while in the female the grooves are less distinct apically, the carina is sometimes scarcely evident, and the distal punctation is sparse and fine. The sculpture is a relative character, and only occasionally can the sex be definitely identified by it. The best example of such an instance is found in juglandis Lec. The position of the antennal insertion on the beak is also of importance in sex determination. The female invariably has the antennae inserted nearer the middle of the beak than the male, but the difference in most instances is so slight that it is only useful in a comparison of the sexes. Frequently, however, the difference is so great that the character can be applied to the one sex in the absence of the other; for example, in recessus (Csy.) the antennae are inserted at the middle of the beak in the female and at the distal third in the male. The foregoing characters are those which have been found to occur in several species. In addition, there are several sex differentiation char- acters which are limited to one or two species, such as the costate first and second elytral intervals of the males of naso Lec. and posticatus Boh., the apical concavity of the male protibiae of tibialis n. sp. (Fig. 31a), and the distal emargination of the male metatibiae in anaglypticus (Say) (Fig. 32a). D. THe MALE GENITALIA 1. Morphology: The male genitalia of Coleoptera were treated in a general way by Sharp and Muir (1912), who made a comparative study of various species in this order. In addition, Sharp (1918) pub- lished a preliminary note on the male genitalia of the Rhynchophora in which he discussed the various genital structures found in this group. Verhoeff (1896), Sharp (1920), Hopkins (1921), Kaston (1936), and others have investigated the genital morphology of either a single species or a genus. The only morphological study on the male genitalia of 26 ILLINOIS BIOLOGICAL MONOGRAPHS Conotrachelus was that made by Sharp (1920) on C. brevisetis Champ., a tropical species. In almost all the investigations since 1912 the terminology of Sharp and Muir (1912) has been followed. Kaston (1936) used it, and in addi- tion discussed and tabulated the terms employed by other workers. Included in Kaston’s work is the nomenclature of Snodgrass (1935), which is the terminology employed in this paper, except in those cases where structures are involved which Snodgrass did not consider. Snod- grass’ terms are followed because they are applicable to the various orders of insects, and the author feels that a nomenclature which can be used in this manner is far superior to one which is limited to a single order. In those cases where structures are involved which Snod- grass did not consider, the terminologies of Sharp and Muir (1912) and Sharp (1918) have been followed. Occasionally new terms have had to be devised. The male genitalia are contained within an invagination of the body wall distad of the eighth abdominal segment. The term phallus is used collectively, to designate all the parts of the external male genitalia. The principal structures which make up the phallus (Figs. 1, 3, and 8) are the first and second connecting membranes, spiculum gastrale, phallobase, aedeagus, endophallus, and appendages of these parts. In the following discussion each of these structures except the con- necting membranes will be considered individually. Unless otherwise stated, all data refer to C. nenuphar (Hbst.). The first connecting membrane extends from the body wall to the phallobase (Figs. 8 and 9, dash line), while the second leads from the phallobase to the aedeagus (Figs. 8 and 9, dotted line). Sharp and Muir (1912) named these parts reversely, but Sharp later (1918) designated them as above. The first connecting membrane fits tightly over the strongly sclerotized aedeagus and frequently is difficult to discern. Dorsally the alimentary canal enters this membrane, while ventrally the conspicuous spiculum gastrale arises from it. The second connecting membrane. is doubled upon itself when the aedeagus is in repose and may be triplicated proximad of the aedeagus depending on the position of the phallobase. This membrane in repose is seldom straight as shown in Fig. 8, but more often is creased or wrinkled. In copulation it straightens out and allows the aedeagus to be protruded. The second connecting membrane is usually closely applied to aedeagal struts. The spiculum gastrale (Figs. 1 and 3) is a conspicuous, curved, sclerotized rod found on the ventral surface of the aedeagus arising from the first connecting membrane. Apically it is strongly curved, while basally it divides into two forks between which a heavy membrane extends to form a broad plate. From the inner angle of the forked base a GENUS CONOTRACHELUS DEJEAN—SCHOOF 27 slender internal groove proceeds apically, where it evanesces. The spiculum gastrale extends beyond the basal portion of the aedeagus and varies in width from that shown in Fig. 3 to a slender elongate rod. The majority of the spiculi observed were of the widened type. The spiculum gastrale is attached by muscles ventrally to the sclerotized triangular portions of the eighth sternum, and to the lateral walls of the eighth tergum (Fig. 3, muscles C). These muscles serve to hold the spiculum gastrale in place in the abdominal cavity during copu- lation. Two other sets of muscles attach to the spiculum gastrale, one at its widened apex (Figs. 3 and 8, muscles A) and the other at that edge of the base which is proximad of the phallobase (Fig. 3, muscles B). These two sets of muscles are apparently the retractors and the pro- tractors of the phallobase, as will be seen by comparing Figs. 8 and 9. The retractor group, from the apex of the spiculum gastrale to the phallo- base, appears to be a powerful set of muscles and possibly aids in the retraction of the aedeagus. The protractor set is composed of a much less dense mass of muscles which in some instances is difficult to see. The phallobase (Fig. 1), (tegmen of Sharp and Muir, 1912), consists of-a sclerotized ring bearing two dorsal lobes (epimeres). According to Sharp (1918) the phallobase may also be an incomplete ring in some Rhynchophora, but in Conotrachelus the ring is always complete. The phallobase in Rhynchophora usually is provided ventrally with a single basally directed strut, but in Conotrachelus the median ventral region never develops basally to the extent that it might be termed a strut (Fig. 3). Various forms of this development are shown in Figs. 13 to 18. The epimeres are difficult to discern unless the phallobase is pulled up over the aedeagal struts (Fig. 9). Their shape is quite similar in’ the species of Group I to that shown in Fig. 1, but in Groups IJ, ITI, and IV, they may be much more elongate. The phallobase, in repose, is usually situated at the base of the aedeagus, but in seniculus Lec. it sur- rounds the aedeagus one-third of the distance distad of the base. As previously mentioned, the phallobase is acted upon by two sets of muscles (ieee, 6,-and 9). The most conspicuous structure of the male genitalia is the strongly sclerotized aedeagus. Sharp and Muir term this structure the median lobe and consider the aedeagus as consisting of both the tegmen (phallo- base) and the median lobe (Figs. 1, 2, and 8). The aedeagus is essen- tially a hollow tube inside of which the endophallus is contained. It varies greatly in form in the different species and is the most important structure for specific classification. Dorsally it consists of a pair of heavy sclerotized lateral plates and a median area. This median area when slightly sclerotized as in nenuphar (Hbst.) (Fig. 1) is termed the dorsal plate; when entirely membranous as in naso Lec. (Fig. 59) the dorsal 28 ILLINOIS BIOLOGICAL MONOGRAPHS membrane. When a dorsal plate is present it is separated apically from the lateral plates by membranous areas (Figs. 1 and 52) except in seniculus Lec. (Fig. 56). These membranous areas, of course, are absent in those species having a dorsal membrane (Fig. 58). In either case the lateral plates, which also extend to the ventral surface, unite apically to form either a prominent process (Figs. 53, 66, 67, and 68), a feeble process (Figs. 42 and 50), or sometimes no process at all (Figs. 56 and 63). The dorsal areas of the lateral plates in Group I, particularly beyond the extent of the dorsal plate, become depressed so that subapically the lateral plates are solid dorsoventrally instead of the dorsal and ventral surfaces being widely separated. This may be seen by noting the gradual subapical convergence of the dorsal and ventral surfaces in Figs. 74, 78, and 79. Basally the lateral plates may unite (Figs. 52, 59, 62, and 64) or be separated by a dorsal membrane (Figs. 66 and 68) or a dorsal plate (Fig. 45). Frequently, as in Figs. 42, 46, 47, and 51, there is a faint internal indication of the extension of the dorsal plate to the base. The extent and shape of the dorsal plate and dorsal membrane are quite variable as will be seen by a comparison of Figs. 42 to 68. Neither of these structures extends to the apical junction of the lateral plates; instead each terminates a short distance before the junction. Ventrally, the aedeagus is bounded by the same lateral plates, and the median area here also may be either lightly sclerotized (ventral plate) or membranous (ventral membrane) or both (Fig. 2). Usually the basal portion of the aedeagus is lightly sclerotized and the apical portion membranous, .although the relative proportion of each type is variable (compare Figs. 84 and 85). In a lateral view the ventral membrane is usually the only portion visible. On their ventral surfaces the lateral plates are extended basally in the form of two elongated projections (Fig. 2) which are termed aedeagal struts (median struts of Sharp, 1918, p. 217). These struts are always present in Rhynchophora and assume a variety of shapes and sizes. The same is true in the genus Conotrachelus, although in closely related species they differ but little. In seniculus Lec. the aedeagal struts are small, the aedeagus being eight and one-half times their length, while in crataegi Walsh the struts are three-fourths as long or may even equal the aedeagus in length. The apices of the struts also vary in form. The ventral plate likewise projects basally to give rise to an angulate struc- ture between the aedeagal struts. This median projection is usually difficult to discern, since the second connecting membrane encircles it. Usually the projection extends beyond the basal border of the aedeagus, but occasionally it may be parallel to it as in seniculus Lec. As previously mentioned, the dorsal plate or membrane does not ex- tend to the apical junction of the lateral lobes, so that there remains GENUS CONOTRACHELUS DEJEAN—SCHOOF 29 distad of it an area in which the ventral membrane is visible from above. Since this area is distad of the phallotreme (Fig. 5), it has been termed the prephallotremic area (Figs. 1 and 42). Summarizing, it may be said that the aedeagus is a hollow structure consisting of two heavily sclerotized lateral plates which extend both dorsally and ventrally and are separated dorsally and ventrally by median, membranous, or lightly sclerotized areas. The endophallus (Figs. 4 and 11), (internal sac of Sharp and Muir, 1912; praeputial sac of Verhoeff, 1896), is that structure of the male genitalia which effects the transfer of sperm from the male to the female. It bears the opening of the ejaculatory duct, the gonopore (Fig. 7), (functional orifice of Sharp and Muir, 1912), and is instrumental in bringing about a close connection between this orifice and the mouth of the spermathecal duct in the female. The endophallus is chiefly mem- branous, but also contains sclerotized plates as well as numerous spines. When not in use in copulation, it is usually inverted and contained within the aedeagus (Fig. 4) with the sclerotized, lateral plates of the aedeagus on the sides, the dorsal plate above, and the ventral plate and membrane below. In such a position the endophallus occupies the greater portion of the aedeagal cavity. Usually it remains in this position until the aedeagus is inserted into the female during copulation, but in some species of Lucanidae, Heteroceridae, Lycidae, and Scarabaeidae (Sharp and Muir, 1912, p. 607) the endophallus is permanently everted and is never contained within the aedeagus. Thus it appears that the principal func- tions of the aedeagus are to place the endophallus in a position where it can effect a close connection between the sperm duct of the male and the spermathecal duct of the female, and to protect it while copulatory attempts are being made. In C. nenuphar (Hbst.) the endophallus (Figs. 7 and 11) consists of two large, sclerotized, roughly diamond-shaped plates and a membranous portion which makes up its greater area. The membranous area is covered with numerous spines and is trilobed when fully everted. The lateral, membranous lobes are broad basally and narrowed apically, the spines becoming larger as the lobes narrow. When everted the lateral lobes push out to the sides and curve basally. In this position they doubtlessly function as a holding mechanism in copulation. The middle lobe is directed apically and consists of a broad, dorsal lobe and an elongate, ventral lobe. The dorsal lobe is separated from the lateral lobes by minutely spined or spineless strips, while the ventral lobe is ventrad of the lateral lobes. In repose the ventral lobe hangs beneath and to the side of the main portion of the endophallus (Figs. 4 and 5). In this position, it may be seen to contain many internal spines, all of which are directed apically. The ventral lobe of the endophallus is extremely diff- 30 ILLINOIS BIOLOGICAL MONOGRAPHS cult to evert even in fresh specimens, and only after repeated efforts is extension successful. The dorsal lobe, in comparison, everts readily and may be fully extended even though the ventral lobe is still within the aedeagal cavity. Because of this arrangement of the two lobes, and the fact that when forced out of the aedeagal cavity by vigorous pulling with a needle, the ventral lobe hung limply beneath the dorsal lobe, it was at first concluded that the ventral lobe was incapable of protrusion. The presence of a strongly spinose, internal wall in a passive structure, how- ever, appeared to be a paradox. Up to this time, attempts to evert the ventral lobe had been on the assumption that the lobe was a tubular structure which would evert by a reversal of the internal and external walls such as occurs in the dorsal lobe (compare Figs. 5 and 11). The ventral lobe, though tubular in outline in repose, does not extend in this manner. The tubular outline of the lobe is brought about by a pushing in of the dorsal wall so that a double-layered tube is formed (Fig. 6a). In this way the spines which are present on the lateral edges at the apical tip of the ventral lobe (Fig. 7) approach each other as shown in Fig. 6a. In repose, the tube thus formed has the spines internally and pointing apically. When eversion takes place, the inner spinose layer is thrown upward and laterally (Figs. 6b and 7) and the spines are directed basally. When so extended, the ventral lobe appears to be an accessory holding mechanism for use in copulation. The location of the gonopore between the two sclerotized plates (Fig. 7) instead of at the tip of the ventral lobe would further indicate this type of function for the ventral. lobe. The lobe has muscles attached to its apical end which serve for its retrac- tion and possibly aid in the inversion of the entire endophallus. Although mechanical eversion of the ventral lobe was possible in fresh specimens, the genitalia of one male killed when in copulation showed the ventral lobe within the aedeagal cavity although the remainder of the endophallus was fully everted. This, plus the extreme difficulty of everting the ventral lobe, leads one to the conclusion that the lobe pos- sibly does not extend during copulation but has a more passive role. When the endophallus is everted the two sclerotized plates lie proxi- mad and dorsad of the membranous portion (Figs. 7 and 11). These plates form the transfer apparatus (Sharp, 1918, p. 218), and are of great importance since the ejaculatory duct has its opening between them. Both plates are roughly diamond-shaped, and each contains a hole, the purpose of which is not apparent. Attached to the plates are muscles used to retract the endophallus, while lying between the plates is the small, obscure opening of the ejaculatory duct, or gonopore. Dorsad and proximad of the transfer apparatus is a small, slightly sclerotized plate having teeth along its apical border (Figs. 7 and 11, hinge plate). This GENUS CONOTRACHELUS DEJEAN—SCHOOF 31 structure is attached to the dorsal plate of the aedeagus and serves as a hinge upon which the endophallus is everted. When the endophallus is in repose the sub-basal edge of this hinge plate projects beyond the apex of the dorsal plate of the aedeagus (Figs. 4 and 5). The opening beneath the hinge plate formed by the inversion of the endophallus is termed the phallotreme (Fig. 5). The natural eversion of the endophallus is effected by blood pressure (Sharp and Muir, 1918, pp. 610-11). This phase of the eversion was not studied by the writer, the method of eversion being considered primarily. The points mentioned in the following discussion were determined by artificial eversion of the endophallus with a needle, but the writer feels that the normal method would be the same regardless of the difference in the agent. In repose, the endophallus is as shown in Figs. 4 and 5. The dorsal plate of the aedeagus is level with the lateral plates (Fig. 9), the dorsal lobe is inverted with its spines on the inner wall, the lateral lobes approach each other apically, diverging basally where they pass beneath the trans- fer apparatus. The latter is most evident, being in the approximate central area of the entire sac and just beneath the dorsal plate. The hinge plate has its spines pointing basally and its basal border protruding distad of the apical edge of the dorsal plate. The ventral lobe has its apical end projecting beyond the basal border of the aedeagus beneath the second connecting membrane (Fig. 4, connecting membrane not shown), and the ejaculatory duct may be seen rising from near the ventral membrane of the aedeagus and passing dorsally over the sac to its insertion between the plates of the transfer apparatus (Fig. 5). The courses that these various structures follow during the eversion of the endophallus are shown diagrammatically in Fig. 5 and are also evident by comparison of Figs. 4 and 7. The lateral lobes slowly push out toward the sides, curving basally, while the dorsal lobe area slowly everts apically. At the same time, the hinge plate and the plates of the transfer apparatus swing ventrally so that their basal point shown in Fig. 4 becomes their apical point in Fig. 7. The reversal of these plates requires an increase in the size of the phallotreme (median orifice of Sharp and Muir, 1912, p. 482), and this is accomplished by the elevation of the dorsal plate of the aedeagus (Fig. 11). Extension of the ventral lobe, if occurring, takes place after the lateral and dorsal lobes and transfer apparatus have been fully everted. The complete eversion finds the structures as shown in Figs. 7 and 11, the endophallus presenting an approximately forty-five degree slope. Sharp (1920, Plate IV) found the endophallus in Conotrachelus brevisetis Champ. (a South and Central American species) when everted 32 ILLINOIS BIOLOGICAL MONOGRAPHS to consist of a large ventral bladder-like sac with a distinct small lobe containing the transfer apparatus on the dorsal surface of its base. Sharp considered this position of the transfer apparatus as remarkable, since these plates are usually more closely connected with the wall of the main sac and placed more or less at its apex. In C. nenuphar (Hbst.) a dorsobasal position of the transfer apparatus is obtained, but the apparatus is not set off in a small lobe from the remainder of the sac. Sharp also stated that the extreme hardness and complex shape of the transfer apparatus in C. brevisetis Champ. was unusual in the Curculioni- dae. The writer, although not making a detailed study of the endophallus in other species of Conotrachelus, has noted that a complex, hardened, transfer apparatus does occur in a number of species, such as seniculus Lec., cribricollis (Say), leucophaeatus Fahr., naso Lec., posticatus Boh., fissunguis Lec., anaglypticus (Say), erinaceus Lec., crataegi Walsh, geminatus Lec., tuberosus Lec., and adspersus Lec. In these species, excepting seniculus Lec., the transfer apparatus consists of one to three pairs of sclerotized bars. These bars assume a variety of shapes, some being J-shaped, others elongate and sinuate, and still others semicircular. In some instances the bars protrude into the prephallotremic area as is shown in Figs. 59, 60, and 68. The technique of artificial eversion of the endophallus is simple to explain but difficult to apply. After removal, the genitalia are held in place by a small needle pushed through the phallobase. Since the endo- phallus apparently does not attach below to the ventral membrane but is suspended from the lateral plates, a fine needle with a slightly hooked end is then inserted between the ventral membrane of the aedeagus and the endophallus with the hook turned sidewise. When the needle passes the basal end of the endophallus, it is twisted so that the hook points dorsally. It is then slowly withdrawn, and if a hold on the endophallus has been obtained, eversion is gradually accomplished. Usually, several attempts have to be made before success is attained. In this study fresh specimens were used, and the extension of the endophallus was not so difficult as it would have been in preserved specimens. Sharp and Muir (1912, pp. 483-484) and Sharp (1918, pp. 220-221) described this method of eversion and their study was made on a wide range of Coleoptera with dried specimens up to sixty years of age. When eversion is complete, these workers inject the endophallus with water to restore it to its natural form. The smaller the specimen, the more exacting is the eversion, and in some cases it appears impossible. Specimens that have been killed and preserved in alcohol are not suitable for the ex- tension of the endophallus (Sharp, 1918, p. 221). Specimens which are killed in alcohol and immediately examined, however, give suitable re- GENUS CONOTRACHELUS DEJEAN—SCHOOF 33 sults. In fresh specimens of other Coleoptera, such as Staphylinidae, the endophallus may be everted by gently pressing upon the median lobe (Sharp and Muir, 1918, p. 483). 2. Taxonomic Value: The male genitalia are of distinct taxonomic importance in the genus Conotrachelus. Barber (1919, 1923), however, has been the only worker to use these structures in the taxonomy of this group. He separated males of serpentinus (Klug), aguacatae Barber, and perseae Barber by means of aedeagal differences. As the various struc- tures of the male genitalia are not of equal significance, a brief discussion of their relative taxonomic values is given here. : The two connecting membranes are similar in all the species studied, and the spiculum gastrale appears to be affected by the age of the indi- vidual, so that these three structures are of little taxonomic value. The phallobase, on the other hand, shows some evidence of being useful, perhaps in the separation of groups of species, since it was noted that the epimeres usually are distinctly longer in Groups II, III, and IV than in Group |. There are also differences in the configuration of the phallobase, but in many instances closely related species have phallobases of similar form. In addition, the sclerotization of the phallobase varies within some species, and sometimes its limits are difficult to discern, so that it is not useful in classification. Originally the writer had some hope that the median, ventral area might be of use, since this area is wider than the remainder of the phallobase and is produced basally in various shapes. It was found, however, that this median area varied greatly in form within some species (Figs. 14, 16, and 17), and frequently different species had similarly shaped, basal productions (Figs. 13 and 16). The endophallus is of importance in the definition of groups of species and may be of specific value. In Group I, with the exception of seniculus Lec. and nivosus Lec., all the species have the same type of endophallus as that shown in nenuphar (Hbst.) (Figs. 7 and 11), although in some species it may be slightly modified. Essentially, however, it is the same even though the aedeagi of the various species may differ greatly in form (Figs. 42 to 54). In addition to these aedeagal differences, the external morphological characters of the species are also variable, as will be noted by a brief glance at the descriptions of some of the species in Group I. From this, one may infer that the endophallus is a true index to group relationship even when the other morphological characters of the species are divergent. This relationship is mainly evident by examination of the transfer apparatus which is the prominent sclerotized part of the en- dophallus (Fig. 7). Sharp (1920, p. 75) states: ‘The shape and nature of the transfer apparatus differs greatly in the various forms of Rhyn- chophora, so that it will be difficult to generalize it for the purpose of 34 ILLINOIS BIOLOGICAL MONOGRAPHS definition of the great groups, but it will be found very important in the case of definition of genera and tribes.” The endophallus may possibly be used as a specific character i in those species which have a dorsal membrane instead of a dorsal plate (Figs. 58 to 62 and 64 to 68) and possess several distinct sclerotized bars in the transfer apparatus. When a dorsal membrane is present, the transfer apparatus is visible from above, and the size and shape of prominent sclerotized rods can be observed. Some of the less distinct bars, however, are obscure, so that the true relationship of all the structures in the transfer apparatus cannot be determined unless the endophallus is everted. In the descriptions of the male genitalia of cribricollis (Say), geminatus Lec., and other species of Groups II, III, and IV, mention is made of the shape and position of the prominent bars of the transfer apparatus. The sclerotized bars, when beneath the dorsal membrane, are not shown in the illustrations, since, without being everted, their relationships could not be accurately determined. When the sclerotized bars protrude into the prephallotremic area, they are included in the illustrations (Figs. 59 and 60). A specific difference in the sclerotized bars of these two species is clearly perceptible. The greatest handicap to the use of the endophallus is the difficulty of its eversion, even in fresh specimens. If this handicap is ever overcome, a distinct advance in the phylogeny and taxonomy of this genus will be possible. The genital structure of the most taxonomic significance is the heavily sclerotized aedeagus. The aedeagus shows distinct variations among the different species and yet is constant within a species. There are minor variations in size and shape within a species, as will be seen by compari- son of Figs. 1, 4, and 7, but these variations are too slight to prevent the use of the aedeagus in specific identification. A series of eleven speci- mens of seniculus Lec. from the same locality were examined to de- termine the extent of variation in such a group, and specimens from other localities were also examined. Some slight variations in the dorsal outline were found. In some instances an evident indentation was present at the apical third instead of only a feeble indication as shown in Fig. 56. The lateral plates and dorsal plate also varied slightly in their relative proportions. In no case, however, were the variations such that the aedeagus could be mistaken for that of another species. Numerous specimens of nenuphar (Hbst.) were also examined, and a similar con- clusion was drawn. The specific variations of the aedeagus are illustrated in Figs. 42 to 95. Before discussing the relative value of the parts of the aedeagus, it is necessary to define some of the terms not yet discussed. In a dorsal view, the outer limit of the lateral plate, on each side, is termed the outer curvature (Fig. 42). The inner limit is termed the inner curvature GENUS CONOTRACHELUS DEJEAN—SCHOOF 35 (Fig. 42). From the lateral aspect the upper boundary of the lateral plate is designated the dorsal curvature; the lower boundary, the ventral curvature (Fig. 84). In a dorsal view of the aedeagus the outline of the structure is of utmost importance. For example, its shape in aratus (Fig. 53) is dis- tinctly different from that in elegans (Fig. 51). All other species also differ in this respect. The inner curvature is of less importance, but varies in the different species, as will be seen by a comparison of Figs. 61, 64, and 67. Sometimes this curvature is rather indistinct basally, as is shown in Figs. 60 and 65 (irregular lines). The dorsal plate varies in shape in the different species, but it also may vary quite extensively in the same species. Unless the dorsal plate is exceptionally distinctive, as in aratus (Germ.) (Fig. 53) and in crataegi Walsh (Fig. 57), it is not a reliable character. The presence of the dorsal plate links together all the species of Group I in contrast to those of Groups II, III, and IV, where a dorsal membrane replaces the plate (except in crataegi Walsh). Another distinctive group feature is that the apex of the dorsal plate is usually transverse (Figs. 42 to 54) while that of the dorsal membrane is either V-shaped or semicircular apically (Figs. 62 and 68). Exceptions to these generalizations are found in crataegi Walsh (Fig. 57) which has a dorsal plate that is V-shaped apically, and in seniculus Lec. and hayesi n. sp. which have the dorsal plate incurved apically. In seniculus Lec. the dorsal median area is lightly sclerotized, but no membranous areas are present between the dorsal plate and the lateral plates as in the other species (except nivosus Lec.) of Group I. Another aberration in Group I in regard to the structure of the dorsal median area is found in mivosus Lec. where the dorsal plate is obliterated except for a minute triangular piece basally. It may seem from this discussion that there are so many exceptions that no definite relationships are present. If it be remembered, however, that numerous southwestern and Gulf Coast species are not considered in this study, then these discrepan- cies in the data are explained in part. The writer believes that with a larger series of species the presence of a dorsal plate or membrane and its various intermediate and aberrant shapes may be successfully ex- plained phylogenetically. The dorsal plate usually is difficult to see in glycerine or alcohol mounts unless the endophallus is everted or unless it is heavily sclero- tized, which is rarely the case. If the aedeagus is allowed to dry tempo- rarily, the dorsal plate becomes distinct. When in a liquid mount, con- siderable manipulation is necessary before its shape can be observed. The apical process is variable in its development in various species (Figs. 42, 43, 47, 53, 54, 60, and 62). When a process is present, it is 36 ILLINOIS BIOLOGICAL MONOGRAPHS easy to distinguish between the species, such as in Group I, where nenu- phar (Hbst.) by the possession of a distinct apical process is readily distinguished from its close relatives, buchanani n. sp., 1owensis n. sp., juglandis Lec., and albicinctus Lec. (Figs. 42 to 46). The shape of the process is also of value, as will be noted with the species of Group III (Figs. 66, 67, and 68). Since the apex of the aedeagus is curved ventrally, it is not visible in the dorsal view. Consequently, a separate sketch of the apex in the various species has been made to show its form and prolonga- tion (Figs. 42 to 68). The aedeagal struts do not vary significantly in closely related groups and are not included in the illustrations. The lateral view of the aedeagus (Figs. 69 to 95) is chiefly important for the observation of the dorsal and ventral curvatures. Usually it is less important than the dorsal view. The lateral plates, dorsal plate or mem- brane, and the ventral plate or membrane are visible in a lateral view. The dorsal plate or membrane varies in its prominence depending on whether or not the endophallus is slightly everted. Sometimes it is quite prominent (Figs. 74 to 77), at other times scarcely evident (Figs. 72 and 73). The ventral plate is visible in only a few species (Figs. 84, 85, 86, and 87), but the ventral membrane is usually evident. The dorsal and ventral plates or membranes, however, are usually not of taxonomic importance in a lateral view, since they vary greatly, depending on the position of the aedeagus and the extent to which the endophallus is in- verted. These two structures are included in the drawings chiefly to orient the lateral position of the aedeagus so that comparisons with the illustrations may be made from specimens in the same position. The dorsal and ventral curvatures vary in the different species and are of distinct importance. Comparison of Figs. 86, 87, 91, and 92, as well as the other lateral figures, will illustrate this point. An interesting point concerning the aedeagi is that their length may not be in proportion to that of the adults. Thus the aedeagus of hayesi n. sp. (Fig. 52) is distinctly longer than that of juglandis Lec. (Fig. 42), although the adults of the hayesi n. sp. range from 4.7 to 5.1 mm., and juglandis Lec. from 5.9 to 7.1 mm. The same is true of recessus (Csy.) (Fig. 63) and tuberosus Lec. (Fig. 66), although the adults of both have the same range in length. It appears from this study that excepting those morphological charac- ters on which Groups I to IV are based, the genitalia (aedeagi) are truer indicators of specific relationships than the external morphological charac- ters. Thus, in Group I the aedeagus of falli Blatch. clearly shows that it belongs in the group with nenuphar (Hbst.) and elegans (Say), even though its elytral and prothoracic sculpture is greatly different from that of these species. In Group III, twberosus Lec. has the elytral costae GENUS CONOTRACHELUS DEJEAN—SCHOOF 37 similar to those of nenuphar (Hbst.), yet its aedeagus (Fig. 66) clearly shows that it is related to anaglypticus (Say) and leucophaeatus Fahr. (Figs. 67 and 68). The close affinity of fissunguis Lec. and erinaceus Lec. is also evidenced by similarities in their aedeagi (Figs. 64 and 65), even though externally they are very distinct. The aedeagi in these in- stances indicate that the basic characters on which the groups are erected are valid, and do not fluctuate as do other previously mentioned “super- ficial” characters. V. NOMENCLATURE The principal nomenclatural question in this genus involves the author- ship and the position in the Curculionidae of the generic name Cono- trachelus. Schonherr (1837 and 1845), Agassiz (1842-46), Lacordaire (1866), Provancher (1877), and Scudder (1882) credit Latreille (1835 or 1837) with the name Conotrachelus, while Melshheimer (1853), Gem- minger and Harold (1871), Crotch (1873), Leconte and Horn (1876), Austin (1880), Champion (1904), Blatchley and Leng (1916), Leng (1920), Sherborn (1925), Schulze et al (1929), Hustache (1936), and Neave (1939) cite Schonherr (1837) as the author of the name. Dejean (1835, p. 296, and 1837, p. 321), who first published the name Conotra- chelus, appended Latreille’s name to it, and this has led some authors to credit Latreille with the generic name. Latreille, however, did not publish anything concerning the genus Conotrachelus, and consequently cannot be considered as its author. Schulze et al (1929) and Neave (1939) list Conotrachelus Dejean as a nomen nudum, but as Dejean first published the name and listed seventy-one species (i.e., names) under it, he may be considered as its author if any of the included specific names are valid. Of the seventy-one species listed by Dejean, four are considered valid by the writer. Two species, concentricus (Oliver) (1807) and irroratus (Fabricius) (1801), have definite bibliographic citations. The status of the other specific names, dtaconitus Germar and serpentinus Germar, however, may be considered questionable by some in light of the strictest interpretation of the International Rules of Nomenclature. The facts concerning these names are as follows: Dejean (1835 and 1837) and Boheman (in Schonherr, 1837) both credited Conotrachelus diaconitus and C. serpentinus to Germar, but Germar did not describe either of them. Boheman included under his diagnosis of each of these species (pp. 397 and 402) this synonymy: Conot. id. Dejean Cat. Col. ed. 2. p. 297, ed. 3. p. 321. Balaninus id. Dom. Germ. in Litteris, teste Dom. Schuppel. The first citation in this synonymy refers to Dejean’s placements of 1835 and 1837, while the second apparently has reference to Boheman’s 38 ILLINOIS BIOLOGICAL MONOGRAPHS knowledge, or at least his belief, that the two species known to contempo- rary workers as Balaninus diaconitus Germar and B. serpentinus Germar were the same as the two placed in Conotrachelus, under the same two specific names, by both Dejean and Boheman. Klug (1829) briefly described Balaninus diaconitus and B. serpentinus and listed Germar (in lit.) as the author of both names. Klug’s placement of Germar as the author of these names evidently was done only in deference to Germar, since the latter never published anything in connection with the two species. Consequently, Klug, being the first to publish the two names in connection with descriptive statements, must be considered as their author. The question of the validity of these two names in the Dejean Cata- logue depends on the interpretation of the previously mentioned data. If it can be inferred that Dejean (1835) had reference to Balaninus diaconi- tus (Klug) and B. serpentinus (Klug) when he included under the new genus Conotrachelus the specific names diaconitus Germ. and serpentinus Germ., then these two names can be considered valid in the Dejean Cata- logue. The writer, basing his conclusion on three evidences, believes that such an inference can be made. First, it would appear from Boheman’s (1837) synonymy that Klug’s (1829) species, Balaninus diaconitus Germ. (in lit.) and B. serpen- tinus Germ. (in lit.), Dejean’s (1835) Conotrachelus diaconitus Germ. and C. serpentinus Germ., and Boheman’s (1837) C. diaconitus Germ. and C. serpentinus Germ. are the same pair of species. Dejean and Boheman, as well as Klug, accepted Germar as the author of these species even though by present-day technical standards Klug himself was the author ; similarly, as has been previously shown, Dejean and others accepted Latreille as the author of Conotrachelus. The second evidence is found in the fact that in the Dejean Catalogue the two specific names are in the same consecutive order as they are in Klug’s paper. This possibly is a coincidence, but it may also be an indi- cation that Dejean was actually concerned with the Klug names at the time he erected the new genus Conotrachelus. The third evidence is that it seems unlikely that Dejean would pub- lish the same two specific names and ascribe to each the same author as Klug had done unless he was aware of Klug’s paper and knew that the species (diaconitus and serpentinus) therein placed in Balaninus were the same as those which he (Dejean) placed in Conotrachelus under the same two specific names. It is quite probable that Dejean, Klug, and Germar had even had correspondence (or exchange of specimens and opinions), directly or indirectly, in regard to the two species in question. On this and the two preceding evidences the writer bases his conclusion that the names Conotrachelus diaconitus Germ. and C. serpentinus Germ. GENUS CONOTRACHELUS DEJEAN—SCHOOF 39 as given in the Dejean Catalogue (1835) represent valid species, either of which is available as the genotype. Two of the species originally included under Conotrachelus by Dejean have since been removed to another genus. Schonherr (1837, pp. 467 and 468) made irroratus (Fab.) the type of a new genus Peridinetus, and Chevrolat (1876, p. 229) placed concentricus (Oliv.) in the same genus. Both of these species are Barinae, and their removal from the Cryptorhy- chinae is correct. Before seeing Klug’s paper the writer believed irroratus (Fab.) and concentricus (Oliv.) to be the only valid species of Cono- trachelus in the Dejean Catalogue. Under such circumstances the name Conotrachelus would be shifted to the Barinae, and the unfamiliar syno- nym, Cyphorrhynchus Schonh., would take its place. Fortunately the Klug paper of 1829 was called to the writer’s attention by Mr. L. L. Bu- chanan, and a consideration of the validity of two other specific names, diaconitus Germ. and serpentinus Germ., became possible. This considera- tion has made it possible to retain the name Conotrachelus in the Cryp- torhynchinae, a retention which is highly desirable in view of the well-known concept built around this generic name. The type of the genus Conotrachelus Dejean is diaconitus (Klug), designated by Schénherr (1837, p. 392) as diaconitus Germ. The present synonymy of the genus is as follows: Conotrachelus Dejean, 1835, Cat. Col., ed. 2, p. 296. Cyphorrhynchus Schonh., 1837, Gen. Spec. Curc., IV, pt. 1, p. 458. Glycaria Pascoe, 1880, Ann. Mag. Nat. Hist. (5) VI, p. 181. Edesius Pascoe, 1881, Ann. Mag. Nat. Hist. (5) VII, p. 305. Loceptes Casey, 1910, Can. Ent. XLII, p. 130. The nomenclature of the species, when considered, is discussed under the individual species in the following section. Vin ceAss Lice RON The genus Conotrachelus Dejean belongs in the family Curculionidae, subfamily Cryptorhynchinae, and tribe Ithyporini. It is characterized as follows: prosternum grooved, the groove never extending to meso- sternum; head not transversely sulcate but with a fovea or feeble de- pression separating head and beak; antennal funicle with seven segments sparsely clothed with recumbent and suberect pale setae, suberect setae longer and arranged in whorls; prothorax with distinct postocular lobes ; ornamental setae or scales present on prothorax and elytra, the latter with intervals 3, 5, 7, and 9 frequently costate, the costae of intervals 3 and 9 meeting apically; femora with one or two teeth on apical ventral surface, tibiae with distinct unci, tarsal claws usually divergent, some- times approximate, toothed or cleft; fifth abdominal sternum with a small 40 ILLINOIS BIOLOGICAL MONOGRAPHS tuft of pale, erect setae arising from apical third on each side of middle; aedeagus consisting of two heavily sclerotized lateral plates bordering dor- sal and ventral median areas which are lightly sclerotized or membranous. The species of this genus were separated into six groups by Leconte and Horn (1876) and Blatchley and Leng (1916). In the present classi- fication only four groups are designated. These groups are erected not only for convenience of treatment, but also to exhibit the phylogenetic relations of the species more clearly. Each species is described or redescribed on both the external mor- phological structures and the male genitalia. The redescriptions of previ- ously described species are necessary because older descriptions omitted many of the characters now in use and several of them were based only on one sex. The citations under each specific name are those which have included descriptions of the species. Characters mentioned in the keys and diagnoses (special characters) are usually not repeated in the specific descriptions. Each description is followed by a brief discussion of the dis- tribution, biology, phylogeny, or nomenclature of the species involved. The present locations of the type specimens are indicated by the capital letters inclosed in parenthesis at the end of the type citations. The expla- nation of these abbreviations is on p. 16. A brief glossary is given on p. 142. KEY TO THE GROUPS OF CONOTRACHELUS I. Tarsal claws: divergent: 6.05.00 «ce fo ge soe cee aue + hes O's siesere so oleate teed 2 {= ebarsaliclaws approximates ener ceeds erin eels eee iene Group IV, p. 129 2. Dorsum of prothorax without a median longitudinal furrow; apical half never with a longitudinal ridge on each side of the middle.............. 3 2- Dorsum of prothorax with a median longitudinal furrow on the apical half; furrow bordered on each side by a longitudinal ridge; ridges and furrow sometimes feeble; if so, specimens will have an oblique bar of yellow- ish vestiture behind each humerus...............-ee ee eeeee Group III, p. 118 3. With two femoral teeth, rarely one absent; if only the distal femoral tooth is present, the protibia will be distinctly concave apically (Fig. 3la), or, if the proximal tooth is distinct and the distal tooth obsolete, then the elytral vestiture will be dense and conspicuously white and brown in (co) (6) Aree ce at SUSI ter Wr MLA RUS eens MMe Rhers oc dihtco cho BIbv.c- Group I, p. 40 3- With one femoral tooth (sometimes feeble); if femora also possess a minute distal tooth, the elytral intervals will be set with numerous erect setae, but the elytra will never have a dense vestiture of white and brown recumbent setae, and the protibiae will never be concave apically SE Ue A UTR PTT A rh te) cu ys cart Re RS ORES TS aT eNGiO'G Oc Group II, p. 94 GROUP I The species of this group possess the following characteristics: two femoral teeth (proximal tooth in tibialis n. sp. and distal tooth in nivosus Lec. sometimes obsolete) ; first and second funicular segments of antennae GENUS CONOTRACHELUS DEJEAN—SCHOOF 41 subequal in length and each longer than any of the succeeding segments ; prothorax wider than long, with basal border bisinuate; elytral intervals 3, 5, 7, and 9 feebly to acutely costate; costa of interval 3 usually twice interrupted except in falli Blatch., nivosus Lec., and rarely elegans (Say) ; costa of interval 7 interrupted once or complete, that of interval 9 com- plete, extending from before base to near apex, where it is broader, less distinct, and united with costa of interval 3; interval 10 with a short basal elevation or costa; striae feebly impressed or lacking, more evident apically, succeeded by serial punctures, the latter usually more evident on basal half; vestiture usually condensed posteriorly to form a vague to prominent postmedian band; elytral intervals usually lacking suberect or erect setae; metasternum in males frequently grooved from meso- to metacoxa (Fig. 13); aedeagus with a dorsal plate (except in ntvosus Lec.), this plate being separated apically from lateral plates by mem- branous areas (except in seniculus Lec.) ; transfer apparatus (except in nivosus Lec. and seniculus Lec.) with two roughly diamond-shaped plates (Fig. 4). This group is commonly known as the “nenuphar group.” The desig- nation, however, appears to be a misnomer as only part of the group (species juglandis Lec. to 1owensis n. sp.) is closely related to nenuphar (Hbst.). In addition, the remaining species fall into more or less closely related groups (retentus-affinis; elegans-aratus). Consequently, from a phylogenetic viewpoint it would appear desirable to consider the group only as Group I, omitting any designation of a “typical” species. KEY TO SPECIES OF GROUP I 1. Abdominal sterna 3 and 4 with distinct, coarse punctures, density variable; elytral costa of interval 3 twice interrupted to form three, usually abrupt, elevations, of which the median one is usually hump-like and PIHONAITE LC ee teen crn RAE, cos Corrs ay havent keasuolel eaveia Seek eRoELC MUIR Ae us eves esel Soaveuels eyarmeys 2 1- Abdominal sterna 3 and 4 with sparse, feebly impressed, fine punctures or with coarse punctures; if punctures are coarse the elytral costa of interval 3 (sometimes feeble) will be complete, once interrupted pos- teriorly, or twice interrupted and forming three feeble elevations, of which the median one is never hump-like and prominent; if specimens are less than 4 mm. and have a cream-colored postmedian elytral band and a depressed mesoscutellum, see Couplet 2; or if specimens have their elytral costae feeble and obscured by a dense, principally white ParowiE Vestitire. See WOuplet 10... aksenc vs doce ws C8 Ok 4 bale wee ee 6 2. Abdominal sternum 2 and usually sterna 3 and 4 sparsely punctate; meso- scutellum prominent; aedeagus with a feeble broad apical process Cities. 42 and. G9): size 59-7.) mime. i. fen adecys oe juglandis Leconte, p. 44 2- Abdominal sterna 2 to 4 usually coarsely and densely punctate; if punc- tures are not dense, species will have a depressed mesoscutellum; SAE 1. et 18s oR Maat eS A Ae Wek Rn Lg a 3 3. Mesoscutellum depressed, from lateral aspect gradually sloping downward TEES TM) GUA DS 5 29602) J eee i heigl Me ed De nN re Rae Te SUP le Precerees 4 42 is &- ILLINOIS BIOLOGICAL MONOGRAPHS Mesoscutellum prominent, from lateral aspect abruptly declivent basally (Big. SOB). gis doe lareer. - Specimens of C. aratus (Germ.) or seniculus Lec. would ft equally well Say’s description. Say has indicated the occurrence of varieties, but since these appear to be based chiefly on color and size, too much signif- icance cannot be placed upon them. Leconte (1876) gave a more complete description of elegans (Say), and in his key distinguished it from aratus (Germ.) on the appearance of the postmedian elytral band, this being distinct in elegans (Say) and obscure in aratus (Germ.). This difference is a comparative one and sometimes of little value unless specimens of both species are available. Blatchley and Leng (1916) redescribed elegans (Say), but their characterization was similar to that of Leconte’s. These writers, in their key, separated elegans (Say) and aratus (Germ.) by abdominal characters in addition to the comparative distinction of the postmedian band. In elegans (Say), according to Blatchley and Leng (1916), all the ventral GENUS CONOTRACHELUS DEJEAN—SCHOOF 85 abdominal segments are closely and rather coarsely punctate and the fifth sternum is without tubercles, while in aratus (Germ.) the first and second sterna are very coarsely but not densely punctate and the fifth is finely, more densely punctate and bears two distinct tubercles. These characters of Blatchley and Leng hold in most cases, but there is variation. The abdominal punctation occasionally tends to be less dense on the first and second sterna in elegans (Say), and the fifth sternum may have slight tubercles, while aratus (Germ.) may lack distinct tubercles and have a moderately dense abdominal punctation of the first and second sterna. Such variations lead to confusion, especially when a specimen of either species is lacking for comparison. The characters set forth in the writer’s key appear to be stable and will serve for identification with only one specimen on hand. These characters and the description have been based on the examination of the thirty-three specimens listed under neotype and neoparatypes. All specimens have shown a uniformity with regard to the key characters and to the genital structures. Since the original type specimens have been destroyed and since there is a definite need for a criterion upon which to base this species, the writer hereby designates a male specimen from Jefferson Barracks, Missouri, H. Soltau collection (United States National Museum) as the neotype. This specimen and its neoparatypes are what is commonly interpreted as elegans (Say). In the southeastern region particularly, elegans (Say) appears to be the center of a large complex of forms, all of which, though closely related to it, show variations from it. The majority of specimens that the writer has examined from the northeastern area, however, have been the typical elegans (Say). One male from Massachusetts, considered as belonging to the complex, appears from its genitalia to be more closely related to aratus (Germ.). C. elegans (Say) is closely related to hayesi n. sp. and aratus (Germ.). The latter also appears to be the center of a complex which may be shown to be closely linked to the elegans group when the full complement of the species and the variations of both complexes have been investigated. Conotrachelus hayesi n. sp. Length: 4.7-5.1 mm. Special characters: Abdominal sterna 1 and 2 with a moderately dense punctation, that is, with distinct non-punctate areas present which sometimes are two or more times the diameters of the punctures; post- median elytral band obscure; beak in female with distance (a) approxi- mately three or more times distance (b). Color: Prothorax and elytra uniformly piceous or blackish in female, reddish and black mixed in male. 86 ILLINOIS BIOLOGICAL MONOGRAPHS Head: Densely and semi-coarsely punctate; with a sparse covering of light tan and white setae; beak slender (Figs. 37 and 40) and slightly curved, curvature in male more abrupt at position of antennal insertion; beak distinctly longer than prothorax, longer in female (1.9-2.0 mm.) than in male (1.45-1.50 mm.) ; beak in both sexes distinctly trisulcate laterally from base to above antennal insertion, the median sulcus some- times evanescent basally; dorsal aspect with a distinctly acute or rounded carina, which in male extends to approximately one-third to one-fourth before apex, and in female to approximately one-half before apex; dorsal aspect distad of carina with dense elongate punctures which are more elongate in male than in female; from dorsal aspect, beak in female feebly constricted in area between antennal insertion and apex, no con- striction in this area in male; sparse vestiture of white and tannish setae arising from sulci; antennae in male inserted approximately one-fourth from tip of beak, in female between one-third and one-half, nearer one- third in one specimen, nearer one-half in the other two. Prothorax: Sides sometimes gradually rounded from base to apex, or outline more sharply convergent anterior to middle than posteriorly; coarsely and densely punctate; punctures shallower and several confluent near apex; disc non-carinate and without tubercles; with a sparse vesti- ture of brownish-yellow and white recumbent to subrecumbent setae, the white setae forming a vague oblique line on each side from inside of basal angle to apex; lines sometimes absent. Mesoscutellum: Prominent, from lateral aspect abruptly declivent basally. Elytra: Approximately two-thirds as wide as long; sides subparallel for more than half, then gradually converging to the apex; basal border feebly emarginate before humeri, the latter not prominent ; intervals 3 and 5 feebly to moderately costate; costa of interval 5 interrupted feebly near the base; costa of interval 9 sometimes so feeble behind the middle that it appears to be slightly interrupted; serial punctures coarse from base to before vague postmedian band, smaller apically; sparse vestiture of brownish and whitish recumbent setae; brownish setae chiefly alined on the non-costate intervals; white setae chiefly on slopes of costae and in punctures, slightly more abundant between middle and posterior eleva- tions of third intervals; brownish setae denser behind middle and with white setae forming a vague, ill-defined, postmedian band. Ventral surface: Metasternum not grooved between meso- and meta- coxae in either sex. Abdominal sterna with punctures moderately coarse in female, between fine and coarse in male, especially on sternum 2; sternum 5 and usually 4 more densely punctate than 1 and 2 and some- times more than 3; sternum 3 may or may not be more densely punctate GENUS CONOTRACHELUS DEJEAN—SCHOOF 87 than sterna 1 and 2; sternum 5 laterally depressed, depressions less dis- tinct in male, the latter with a median depression, without or with feeble tubercles; each puncture with a pale amber or whitish fine seta; lateral setae broader and white. Legs: Femoral teeth more prominent in female; metaunci of male dentate (Fig. 28), those of female not dentate; femora and tibiae with a sparse covering of yellow and white setae; setae denser on apical por- tion of metafemora at position of teeth. Male genitalia: (Figs. 52 and 79). Aedeagus elongate, two and one- half times as long as wide at base and approximately four times as long as the aedeagal struts, sides subparallel, slightly widened at apex; apex feebly bisinuate; dorsal plate merging with lateral plates approximately one-third from base. Length 1.197-1.209 mm., width at base .461 mm., aedeagal struts .187-.286 mm. This species is named for Professor W. P. Hayes, Department of Entomology, University of Illinois. Type locality: Northern Illinois. Holotype: Male, No. 1, Illinois State Natural History Survey. Allotype: Female, Northern Illinois, United States National Museum Type No. 55124. Paratypes: Northern Illinois; No. 2, , (ISNHS); Henry County, Iowa; April 24, 1939, 9, (HFS); West Carrol, Louisiana, 1-14, under bark, 9, (USNM). Distribution: Recorded only from above localities. Biology: No data are available for this species. Remarks: C. hayesi n. sp. belongs between elegans (Say) and aratus (Germ.) resembling in certain respects both of these species. The shape and length of the rostrum is similar to elegans (Say), but the abdominal punctation, structure of the meso- and metaunci in the males, and the distinctness of the postmedian elytral band more closely resemble aratus (Germ.). The similarity in external characters, however, is not correlated with male genital likenesses. The aedeagus of hayesi n. sp. is distinctly different from that of either elegans (Say) or aratus (Germ.) as can be seen by a comparison of Figs. 51, 52, and 53. In a lateral view, however, the aedeagus of hayesi n. sp. (Fig. 79) does resemble that of elegans (Say) (Fig. 78) more closely in contour than that of aratus (Germ.) (Fig. 80). All specimens of aratus (Germ.) or elegans (Say), however, even though larger in size than hayesi n. sp. have the aedeagus distinctly shorter than this species. The marked genital differences between hayesi n. sp. and both elegans (Say) and aratus (Germ.) indicate that there are probably other unknown species which would fall into this group. 88 ILLINOIS BIOLOGICAL MONOGRAPHS Conotrachelus aratus (Germar) Cryptorhynchus aratus Germar, 1824, Insectorum Species Novae, Halle, p. 283. Conotrachelus aratus (Germ.) Schonherr, 1837, Schonh. Gen. Spec. Curc., IV, pt. 1, p. 457; Boheman, 1845, Schonh. Gen. Spec. Curc., VIII, pt. 2, p. 26; Leconte, 1876, Rhynchophora N. A., Proc. Amer. Philos. Soc., XV, No. 96, p. 228; Blatchley and Leng, 1916, Rhynchophora N. E. Amer., p. 473; Mutchler and Weiss, 1925, Conotr. N. J., Circ. 87, Bur. Stat. and Insp., Dept. Agr., Node. 20; Length: 4.35-5.75 mm. Special characters: Femoral teeth evident in both sexes. Color: Prothorax and elytra piceous, black, and red mixed. Head: Semi-coarsely punctate; punctures sometimes indistinct; with a sparse vestiture of whitish and tannish setae; beak stout and curved (Figs. 38 and 41), curvature sometimes abrupt apically in male; as long as or longer than prothorax, subequal in length in both sexes; beak trisulcate laterally between base and antennal insertion; lower sulcus always distinct, others varying from distinct to obscure, especially the median sulcus which sometimes is replaced by large punctures; dorsal aspect carinate from base to beyond middle; carina in female sometimes evanescent before or at the middle, feeble or moderately prominent, more acute in male; aspect distad of antennal insertion with fine elongate punctures; punctation moderate to dense, usually more so in male, the surface appearing minutely sulcate; sparse vestiture of tan and white setae arising from sulci; antennae inserted approximately one-fourth from tip in male, nearer one-third in female. Prothorax: Sides gradually rounded from base to near apex, then con- stricted; densely and coarsely punctate; punctures less distinct apically; with four feeble tubercles on disc, one pair transversely at the middle, the other between median pair and base; median pair most evident and present even when posterior set is obsolete; disc on each side sometimes depressed between median and posterior tubercles; with either a feeble carina from between median tubercles apically or non-carinate; sparse vestiture of elongate tan and white recumbent to subrecumbent setae, white or light tannish setae on each side forming a vague, curved line from inside of basal angle to apical border; lines approach apically but do not meet. Mesoscutellum: From lateral aspect usually sloping steeply basally or abruptly declivent. Elytra: Approximately one-third longer than wide; sides subparallel for more than half, then gradually converging to the apex; humeri rounded, variable in prominence; basal border emarginate (sometimes feebly) before humeri; intervals 3, 5, and 7 feebly to moderately costate ; GENUS CONOTRACHELUS DEJEAN—SCHOOF 89 elevations of interval 3 feeble to moderate, the median one most prom- inent; costa of interval 5 usually interrupted twice, interruptions some- times feeble; costa occasionally complete posteriorly, elevations usually feeble; serial punctures feeble to distinct; sparse vestiture of brown, brownish-yellow, tan, and white recumbent setae; relative abundance of each type variable; when whitish setae are well scattered, abundant, and mixed with light-tannish ones, the elytra have a grayish cast; when brownish-yellow and brown setae predominate, a tannish to brownish hue. is present; lighter setae condensed in an ill-defined postmedian band and possibly in a brief line at base of interval 3. Ventral surface: Metasternum in male grooved from meso- to meta- coxa; grooves absent in female. Abdomen: Punctation of sterna 1 to 5 varying from moderately dense (Fig. 34) to dense, punctures coarse, those of sternum 1 usually larger than those of sterna 2-5; sterna 3 and 4 usually more densely punctate than 1 and 2; sternum 5 more densely punctured than sterna 1-4, punctures becoming finer apically, usually with two distinct tubercles on either side of the middle apically, tubercles sometimes feeble; each puncture with an elongate, usually fine, pale amber seta; lateral setae broader and white; vestiture usually most evi- dent on sternum 5. Legs: Femoral teeth small; femora and tibiae with sparse vestiture of tan and white setae, most frequent on distal third of metafemora, sometimes forming a band. Male genitalia: (Figs. 53 and 80). Aedeagus one-fourth to one-third longer than wide at base and approximately one-fourth longer than aedeagal struts; apex abruptly narrowed to form a prominent process ; dorsal plate broad apically and narrowed at the base; basal border may have a smoother curve than that shown in Fig. 53. Length .796 mm., width at base .531 mm., aedeagal struts .600 mm. Type locality: Kentucky. Type: Zool. Univ. Mus., Halle, a. S. Plesiotypes: ALABAMA: Mobile County, H. P. Loding, 9 (USNM) ; ILt1No1s: Urbana, September 9, 1925, V. G. Smith, ¢, (CAF) ; Kansas: Riley County, April 24, May F. Marlatt, ¢, 22, (WPH), °, (HFS), 2, (USNM) ; Topeka, June 13, Popenoe, ¢ , (USNM) ; Onaga and Wil- son County, June 7 and April 23, Wickham, 22, (USNM); Mississipp1: Poplarville, April 27, 1926, pecan L401, W. B. Tate, ?, (HFS); Wiggins, March 24, 1929, hickory petioles, J. P. Kislanko, 9, (USNM) ; Texas: Columbus, May 6, Hubbard and Schwarz, 9, (USNM). Distribution: Ranges from Massachusetts to Illinois and Kansas, south to Alabama and Mississippi, and southwest to Texas. 90 ILLINOIS BIOLOGICAL MONOGRAPHS Biology: Since aratus (Germ.) in the past has been confused with tibialis n. sp., the biological information given under tibialis n. sp. (p. 93) can probably be applied to aratus (Germ.) as well. Two specimen records indicate Hicoria as a probable host: “pecan” (Poplarville, Miss., L. B. Tate) and “hickory petioles” (Wiggins, Miss., J. P. Kislanko). Remarks: C. aratus (Germ.) is another North American species about which a great deal of confusion has arisen. In this instance the type, although possibly still in existence in Europe, is not available, especially at the present time, to American workers. Germar (1824) described aratus with Kentucky as the type locality: It was not again characterized until 1876. At that time Leconte (1876, p. 228) stated that he referred, with some hesitation, to this species a speci- men from Texas, 4 mm. in length. Leconte distinguished this specimen of aratus (Germ.) from all other members of Group I by the punctation of the abdominal sterna: first and second very coarsely but not densely punctured, third and fourth strongly punctured, fifth finely and more densely punctate with two distinct tubercles. Blatchley and Leng (1916, p. 473) gave a similar description, asserting that avatus (Germ.) could easily be distinguished from allied species by the abdominal punctation and the presence of the two tubercles on the fifth sternum. Mutchler and Weiss (1925), in a descriptive key, characterized this species by its color, vestiture, and elytral sculpture, all characters of questionable value in this section of the genus. From this summary, it appears that the abdominal punctation and tuberculation are the principal characters to rely upon. Germar’s original description is general and can also be applied to elegans (Say) or retentus (Say). Several of the specimens on which the author’s redescriptions are based agreed with the type of abdominal punctation and tuberculation set forth by Leconte. Others, however, show variations, although the speci- mens are all the same species. Of four specimens from the same locality and of the same date, three show distinct tubercles on the fifth sternum, but the fourth is only feebly tuberculate. The abdominal punctation also shows similar variation; in specimens from the same locality some show the not-dense punctation specified by Leconte and Blatchley and Leng, _while others have a dense punctation. Since such variations occur in specimens from the same locality, the writer feels that he is justified in considering these specimens to be aratus (Germ.) even though their structures sometimes do not fit exactly the specifications set forth by previous authors. Another character of Leconte and Blatchley and Leng that does not fit some of these specimens is that concerning the non-inter- ruption anteriorly of the elytral costae of the fifth intervals. These GENUS CONOTRACHELUS DEJEAN—SCHOOF 91 costae are usually interrupted at this point, but they are too variable in form in this section of Group I to be used as definite taxonomic indica- tors; therefore, such a digression is not significant. Leconte and Blatchley and Leng also used the prominence of the postmedian elytral band as a means of separating elegans (Say) and aratus (Germ.). This character is of value, but with only one specimen on hand its use is sometimes limited. Germar (1824) gave the size of aratus as similar to that of Notaris acriduli, which varies in length from less than 4 to 5 mm. The specimens interpreted as aratus (Germ.) vary from 4.35 to 5.75 mm. Leconte (1876) gave the size of aratus (Germ.) as 4 mm., but a measurement of his Texas specimen places the length at 4.35 mm. C. aratus (Germ.) is most closely related to tibialis n. sp., from which it is separated by the characters given in the key. Conotrachelus tibialis n. sp. Length: 4.5-5.75 mm. Special characters: Males with proximal femoral tooth absent or obsolete ; sides of prothorax sometimes distinctly bulging near apical third. Color: Prothorax and elytra reddish and black mixed. Head: Semi-coarsely and densely punctate; with a sparse vestiture of light tan and pale white setae; beak stout, curved, longer than pro- thorax (rarely shorter in male), and longer in female than in male; male beak with three lateral sulci from base to above antennal insertion; median sulcus less distinct than others and with large, deep punctures; dorsal face of beak moderately to acutely carinate from base to distad of middle; tip distad of carina densely and finely punctate, punctures so dense that tip appears finely sulcate; female beak with less distinct sulci and with only a feeble carina; sulci and carina sometimes lacking; dorsal surface distad of antennal insertion with fine distinct punctures, moderate to dense in composition; beak in both sexes sparsely covered with white and tan setae which arise from sulci when these are present or from punctures which replace sulci; antennae inserted approximately one- fourth from tip in male, nearer one-third in female. Prothorax: Distinctly wider than long; sides usually rounded, some- times with a distinct bulging near the apical third; with dense coarse punctures, less evident apically, occasionally with a feeble indication of two tubercles on disc behind middle ; sometimes with a feeble longitudinal carina on disc from middle to one-fourth before apex; disc frequently with two depressions behind middle; vestiture sparse, consisting of white and tan recumbent to subrecumbent setae, usually one to a puncture; 92 ILLINOIS BIOLOGICAL MONOGRAPHS lighter setae condensed on each side to form a faint sinuate line from inside of basal angle to apex; lines approach apically but do not meet. Mesoscutellum: From lateral aspect abruptly declivent basally. Elytra: Approximately one-third longer than wide; sides subparallel for more than half, then gradually converging to apex; basal border with feeble emarginations inside of humeri, the latter rounded and not prom- inent; intervals 3 and 5 feebly to moderately costate; elevations of interval 3 feeble; interval 5 with costa either once or twice interrupted ; when only singly broken, interruption either anterior or posterior; costa sometimes acute and occasionally complete; serial punctures large and quadrate anterior to postmedian band, smaller at band and behind it; sparse vestiture of mostly brownish and tannish recumbent setae; whitish setae usually present but not as abundant as darker ones; light tan and light brown setae condensed in a postmedian band, usually vague, rarely distinct ; a faint line of light tan setae at base of third interval. Ventral surface: Metasternal grooves absent in both sexes. Abdominal sterna 1-4 coarsely punctate; punctures numerous, sometimes dense; those of sterna 3 and 4 usually slightly denser than those of 1 and 2; sternum 5 more densely and finely punctate than others, punctures on basal third approaching in size those of preceding sternum; punctation on apical half obscure in female; two, usually distinct, tubercles on apical third in male, those of female feeble to distinct; each puncture with a fine, pale amber seta; lateral setae broader, white and pale-white in color, forming obscure patches on sterna 2-5. Legs: Females with femoral teeth small but evident; protibiae usually distinctly mucronate proximad of unci; mucrones present on meso- and metatibiae but difficult to detect; femora and tibiae of both sexes with a sparse vestiture of light tan and whitish setae which are denser on apical third of metafemora than elsewhere. Male genitalia: (Figs. 54 and 81). Aedeagus one-fourth to one-third longer than wide at base, and one-fourth to one-third longer than aedeagal struts; sides slightly widened apically ; apex bisinuate and with a distinct process; dorsal plate variable in its extent; basal border of aedeagus sometimes a smooth curve instead of angled as shown in Fig. 54. Length .562-.649 mm., width at base .387-.425 mm., aedeagal struts .379-.476 mm. Type locality: Mendenhall, Mississippi. Holotype: Male, United States National Museum Type No. 54310, April 18, 1911, J. E. Boggan, $:3042 (USNM). Allotype: Female, Mendenhall, Mississippi, April 18, 1911, J. E. Bog- gan, S:3042 (USNM). Paratypes: Towa: Mt. Pleasant, May 7, 1930, Jones, 6, (WPH); GENUS CONOTRACHELUS DEJEAN—SCHOOF 93 Iowa City, Wickham, 2, (HFS) ; Intinors: Southern Illinois, H. Soltau, 8, (USNM); Kansas: Wilson County, April 23, 1896, on hickory buds, 2, (MSC); Loutsiana: New Iberia, June 6, 1896, Coll. H. Soltau, 2, (USNM); No. 4676, other data illegible, ¢, (USNM); Massacuu- SETTS: Southboro, May 30, 1923, C. A. Frost, 9, (USNM) ; Missitssi1prr: Poplarville, May 29, 1926; pecan L401, W. B. Tate, ¢&, (USNM); Missouri: Jefferson Barracks, Coll. H. Soltau, ¢, (USNM); New York: Westbury, L. I., May 25, 1916, Hicoria, A. B. Champlain, ¢, (USNM); West Vircinia: French Creek, May 29, 1920, F. E. Brooks, Quaintance No. 21101, jarred from branches of young hickory trees, identified as C. aratus, 8, (HFS), 9, (USNM). Distribution: Ranges from Massachusetts and New York to Iowa and Kansas, south to Mississippi and Louisiana. Biology: As both tibialis n. sp. and aratus (Germ.) have been con- sidered as aratus (Germ.) in the past, it is difficult to evaluate the avail- able biological literature. From specimen records both species appear to have the same host, Hicoria, and in all probability their life histories are somewhat similar. Brooks (1922) gives an account of the biology of aratus (Germ.), but on the basis of the information on two paratypes (Quain- tance No. 21101) the species with which he worked was tibialis n. sp. In this study Brooks’ data, therefore, are discussed under C. tibialis n. sp. One definite record, however, does not eliminate the possibility that Brooks also worked with aratus (Germ.), since the two species have the same host and are very similar in appearance. Consequently, the writer feels that Brooks’ data may also, in the absence of more definite informa- tion, be applied equally well to aratus (Germ.). C. tibialis n. sp. has been recorded only from hickory, Brooks (1922) listing it as attacking Hicoria minima, H. ovata, H. alba, H. glabra, and H. pecan. The tender tips and leaves of these trees usually wither and drop as a result of the egg-laying and feeding of the curculio. No instance of serious loss from its activity, however, has as yet been reported. In the spring, soon after the hickory buds open, the curculios emerge from hibernation, the females commencing oviposition when the shoots are but a few inches long. Each egg is placed in a shallow cavity at the side of an elongate slit made in the bark of the twigs and leaf petioles. During this period of oviposition the adults also feed on the young growth. The egg hatches about a week after deposition, the resultant larva usually feeding in the center of the bulb-like swelling at the base of the leaf petiole. Sometimes it also mines the pith of the shoots and leaf stems. Larval activity occurs in the spring and early summer when the growth is new and tender. When full grown the larvae burrow one-half to two inches below the surface of the soil for pupation. Two to three weeks 94 ILLINOIS BIOLOGICAL MONOGRAPHS later (midsummer) the adults issue from the ground. In autumn they go into hibernation until spring. ’ Brooks (1922) states that during the period of his investigations at least 50% of the larvae died from parasitism. Three parasitic flies, Myiophasia globosa Towns., Cholomyia longipes Fab., and Chaetoch- lorops inquilina Coq., as well as an unidentified species of hairworm, were reared from larvae. The work of tibialis n. sp. has sometimes been ascribed to C. elegans (Say). Remarks: The remarkable form of the protibiae and the aedeagal differences easily separate the males of tibialis n. sp. from aratus (Germ.). The females, on the other hand, are difficult to distinguish, and the char- acters given in the key appear to be the best indicators of specific distinc- tion. The writer is not completely satisfied with these characters since occasionally a female specimen turns up which by their use might pos- sibly be referred to either species. GROUP II The species listed under this group were divided into two groups by Leconte and Horn (1876, p. 421) and Blatchley and Leng (1916, p. 467). The characters which these writers used for the separation of the two groups were based on the structure of the beak, which in one group was slender and much longer than the head and thorax, while in the other it was rather stout, curved, and scarcely longer than the head and thorax. From a study of the species in these two groups it appears that the above writers had before them when they erected these groups only females of several of the species in the long-beaked group. In addition, by examina- tion of Leconte’s types, it has been ascertained that he had only the females of adspersus Lec. and naso Lec. before him, and this fact in all probability led to his arrangement of the key which Blatchley and Leng have followed. The key of these workers is valid when females alone are considered. Unfortunately, the males of the long-beaked group have snouts that resemble those of the short-beaked group, and this fact nulli- fies the validity of the key. Therefore, it has been necessary to consolidate these two groups into one in order to obtain a key which would avoid the confusion introduced by the use of the beak as a group characteristic. In addition, the division of Group II into two parts by these authors placed the species of naso Lec. and posticatus Boh. in different groups. Examination of these species shows that the form of the aedeagus, shape of the mesosternum, prothoracic sculpture, abdominal punctation, shape of the male metaunci, and elytral sculpture (especially the presence of GENUS CONOTRACHELUS DEJEAN—SCHOOF 95 the costate first and second elytral intervals in the males) are extremely similar in both species and indicate a very close relationship between the two. Consequently, it appears to the writer that to put these two species in separate groups would be wholly ignoring an obvious affinity. In the past, Group II has been known as the “crataegi group.” As crataegi Walsh is phylogenetically isolated from the other species in the group (as well as from all other known species of United States Cono- trachelus) this designation is an unfortunate misnomer. As in Group I, reference to any one species as typifying the group should be omitted. Group II is here characterized by the presence of one femoral tooth, but a second feeble tooth (denticle) is usually present in cribricollis (Say) ; relative length of first and second funicular segments of antennae variable; prothorax wider than long, longitudinally carinate or not car- inate; mesoscutellum from lateral aspect abruptly declivent basally; elytral intervals 3, 5, 7, and 9 acutely costate, feebly convex, or flattened ; costae, when present, usually complete, intervals never with abrupt elytral elevations; vestiture of recumbent setae, scales, or scale-like setae; sub- erect to erect setae usually present on elytral intervals and sometimes in prothoracic punctures; recumbent setae not condensed in a broad post- median band; metasternum in male never grooved from meso- to metacoxa; male sometimes with dentate metaunci; aedeagus with a dorsal membrane (except in crataegi Walsh), frequently with an apical process, and with the transfer apparatus a complex of sclerotized bars. KEY TO SPECIES OF GROUP II 1. Humeri truncate and dentiform; prothorax prominently and broadly ele- vated in the median discal area; aedeagus with dorsal plate, the latter sleity ayovecvllhy, (She SYA iGo somone paeeiate cco an caacan acc crataegt Walsh, p. 96 1- Humeri not truncate or dentiform; prothorax never prominently elevated in the median discal area; aedeagus with a dorsal membrane, never as Smanaa. te eG y/eeee ong Aap einoe ne enor bn aac Gerrern DAL Noe aD Torco pao G 2 2. First funicular segment of antenna as long as the second and third com- bined; beak distinctly longer than the prothorax; aedeagus as shown in Biome e lene theOlo=7-2) tMtnlias mses ersicyerevsis erat cre sacra adspersus Leconte, p. 99 2- First funicular segment of antenna usually subequal to the second only, rarely equal to the second and third combined; if so, the specimens will be less than 3.2 mm., have the beak and prothorax subequal in length, iidehavexthesacdeactis aseshowwile ti oy OShiemyyetoc teieioe eietal reece ie ois a= 3 3. Prothorax with a distinct longitudinal, median carina; mesosternum with Miterolateralaaneles! tuiincate anda prominent saci si deseo iie ioninrels « 4 3- Prothorax not carinate; mesosternum never with anterolateral angles ENIMICATCmANG ap rOMMune Mt ceres staveaes. se cere eee ici aeralennte ercretonsiWe oats och ncera 6 4. Profemoral tooth absent or obsolete, the apical ventral emargination of the profemur (viewed posteriorly) broad (Fig. 96)........ naso Leconte, p. 101 4- Profemoral tooth distinct, the apical ventral emargination of the profemur deepratidamore actite: (E1gs, O7sand98) =< .2.5 eset. sleeve saree taaieblnrtede e = « 5 96 ILLINOIS BIOLOGICAL MONOGRAPHS 5. Male:. metaunci dentate; antennal insertion almost reaching lateral apical emargination of beak (Fig. 108); protibia bearing on its apical margin, adjacent to uncus, long, slender, curved, light-tannish setae; setae much longer than uncus and usually in a tuft, sometimes also present on mesotibia; elytral interval 2 not costate; aedeagus as shown in Figs. 99 and 103; female: metaunci not dentate; beak slender (Fig. 101), the distance (a) between lateral apical emargination of beak and anterior margin of ball of antennal scape three or more times the distance (b) between dorsal and ventral surfaces of beak at position of antennal insertion