Pbysocephala bwgessi (Williston). Courtesy E. S. Ross. 4 BULLETIN OF THE CALIFORNIA INSECT SURVEY VOLUME 6, NO. 2 THE CONOPID FLIES OF CALIFORNIA (DIPTERA) BY SIDNEY CAMRAS (Chicago, Illinois) and PAUL D. HURD, JR. (Department of Entomology and Parasitology, University of California, Berkeley) UNIVERSITY OF CALIFORNIA PRESS BERKELEYANDLOSANGELES 1957 BULLETIN OF THE CALIFORNIA INSECT SURVEY Editors: E. G. Linsley, S. B. Freeborn, P. D. Hurd, R. L. Ushger Volume 6, No. 2, pp. 19-50, 4 figures in text, 25 maps, frontis. Submitted by Editors, October 26, 1956 Issued Sept. 3, 1957 Price, 75 cents & UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES CALIFORNIA CAMBRIDGE UNIVERSITY PRESS LONDON, ENGLAND PRINTED BY OFFSET IN THE UNITED STATES OF AMERICA THE CONOPID FLIES OF CALIFORNIA (Diptera) BY Sidney Camras and Paul D. Hurd, Jr. INTRODUCTION The conopid flies are characterized by the closed Zo~logy,Harvard College (M.C.Z.); California In- or narrowed first posterior cell of the wing (fig. 2) sect Survey, Department of Entomology and Para- and in all the Nearctic forms by the elongated sitology, University of California (C.I.S.); Mont A. proboscis. These flies, especially the members of Cazier, American Museum of Natural History the subfamily Conopinae which have the base of (A.M.N.H.); H. Dietrich, Department of Entomolcgy, the abdomen narrowed and somewhat thread-waisted, Cornell University (C.U.); H. J. Dybas, Chicago superficially resemble some of the wasps and cer- Museum of Natural History, (C.M.N.H.); G. F. fain asilids, bombyliids, syrphids, and tachinids. Knowlton, Utah State Agricultural College They ate found frequently around flowers. (U.S.A.C.); A. T. McClay, Department of Entomology To date, thirty-nine species of sk genera are and Parasitology, University of California, Davis definitely known from California. Nine others have (U.C.D.); J. A. G. Rehn, Academy of Natural been included in the present report because it Sciences of Philadelphia (A.N.S.P.); E. S. Ross, seems likely that they will be eventually found to California Academy of Sciences (C.A.S.); Curtis occur here. One other species has been included, Sabrosky, U.S. National Museum (U.S.N.M.); and but the record of its occurrence in California is P. H. Timberlake, Citrus Experiment Station, Uni- open to question. versity of California, Riverside (U.C.R.). Much In matters of identification, the great variability additional material is in the private collection of of many of the species and the frequent occurrence Sidney Cams (S.C.). of atypical and intermediate specimens must be considered. Therefore, the keys cannot cover all the aberrant individuals. The latest .work covering BIOLOGY the North American Conopidae is that of Parsons (1948) and should be consulted for a more complete The conopid flies are all solitary, internal para- synonymical bibliography. sites of Hymenoptera (especially wasps and bees), Gber (1919) has provided a very convenient Orthoptera (one reared from the genus Oedipoda), summary of the knowledge pertaining to the family and Isoptera (a single record of a larva described from a world viewpoint. by Silvesai, 1926, from the head of the Philippine The present study includes all of the species Tennes gilvus Hagen). known from Alberta, Arizona, British Columbia, Braucr (1883) and Meijere (1903, 1912) are fun- California, Idaho, Lower California, Montana, damental to any ethological study of the family. Nevada, Oregon, and Washington. Their investigations not only embody a synthesis Mrs. Celeste Green, Scientific Illustrator, De- of the literature pertaining to the immature stages partment of Entomology and Parasitology, Uni- and biology, but more importantly contain much versity of California, Berkeley, has prepared the original information. Townsend (1935) has sum- illustrations which accompany this study. marized the high lights of the conopid ethological The material which has formed the bsis of this studies since that time and has provided certain paper and which we have been privileged to study dam on the immature stages of Physocepbala was made available by the institutions listed be- sugitla+ia (Say). low. To the individuals in charge of these collec The most informative biological study made on tions as well as those acknowledged elsewhere in an American conopid, Physocephala affinis (= the present paper we would like to express our texunu), is that by Bohart and MacSwain (1939). gratitude: Drs. G. E. Bohart, U.S. Legume Seed Although this investigation was conducted as an Research Laboratory, U.S. Department of Agricul- adjunct to an ethological study of its host, Epi- ture, Logan, Utah (G.E.B.); W. L. Brown, Jr., and bembex occidentalis. the data obtained and pre- P. J. Darlington, Jr., Mweum of Comparative sented more fully by Bohart (1941~)were s& I: 191 20 BULLETIN OF THE CALIFORNIA INSECT SURVEY ficiently informative to demonstrate the usefulness complished by the female pouncing upon the host of biological criteria in the interpretation of the during flight and inserting the ovipositor briefly species problem in this genus. A more detailed between the abdominal segments. Prolonged con- consideration of these works is presented in the tact has been observed, but more often the en- discussion of the genus Physocephala. There have counter between the ovipositing fly and its host been a few additional biological studies dealing is of short duration. There seems to be no evident with the American conopids, but since most of effect upon the host following oviposition or during these are concerned with host relationships, they the subsequent development of at least the early are considered or cited elsewhere in the present larval instars of the parasite. Apparently other study. wise normal bees containing third instar conopid Fig. 1. Puparium of Physocephala texana (Williston) within abdominal cavity of its dead host, Epibembix occidentalis beutenmuelleri (FOX). Courtesy E. S. ROSS. There is reason to believe that a certain degree larvae are observed visiting flowers in the search of developmental host specificity is manifest by. for nectar and pollen. The feeding activities of the at least some species of conopids. This is par parasitic larva are restricted to the abdominal ticularly evident in the paper of MacSwain and cavity since there has been no indication in any Bohart (1947) where these authors found Myopa of the studies that the larva attempts to gain ac- mbida ovipositing in three species of Andrena, but cess to the thorax. apparently unsuccessfully on at least one of the Shortly before pupation the host dies, and the con- species. opid completes its development within the ab Oviposition in the majority of our species is ac- domina1 cavity. Emergence of the adult fly from the CONOPID FLIES OF CALIFORNIA 21 abdomen of the dead host seems always to occur 7(3). Tibiae unarmed at apices (Dalmanninae). between the segments and may be either dorsal or ......... Datmannia (p. 45) ventral. Tibiae with apical spur (Stylogasterinae) . There is but one generation produced a year in ......... Stylogaster(p. 47) all the species studied thus far; however, there is reason to believe that some of the species may be multivoltine as are their hosts. Genus Pbysoconops Szilady Much additional information is needed before it The majority of the New World species included in will be possible to provide biological criteria for the definition of our species and genera. this genus were described in the genus Conops. The distributional maps accompanying this study Our species are very similar in their wasplike show the known localities of occurrence in Cali- habitus to the genus Physocephala. fornia (indicated by various forms of circles) for The New World Physoconops have recently been each species, and the geographic range (various reviewed by Camras (1955). In that study the genus overlays) of the species in the smaller inset maps. has been divided into six subgenera, three of Where there is not sufficient distributional in- which are represented in California and may be separated by means of the following key. formation on a California species to warrant in- terpretation by a map, the California records are cited in full. The following key includes in addition to those Key to the California Subgenera of genera known from California, the genera Robett- P by so conop s sonomyia and Stylogaster, both of which probably occur in the state. 1. Third antennal segment more than two- thirds as long as second; front shorter than wide ..............2 Third antennal segment less than two- to the Subfamilies and of Key Genera thirds as long as second; front generally California Conopidae longer than wide .....Physoconops Antennae with terminal style (Conopinae) 2 2. Vertex small, much shorter than front ... Antennae with dorsal arista ......3 ............Pachyconops Vertex large, as long as front Gymconops Anterior cross vein (rm) near middle of discal cell (1st M,) (fig. 2c); hind femur The subgenus Gymconops includes three species uniformly thickened. ........ of which only one, Physoconops sylvosus (Willis ........ PhysoconoPs (Po 21) ton) the type of the subgenus, is known from Cali- Anterior cross vein (rm) well beyond mid- fornia. This subgenus may be recognized by the dle of discal cell (1st MJ (fig. 2b); hind large vertical swelling which extends halfway femur irregularly thickened at base ... from the occiput to the base of the antennae. ........ Physocephala(p. 25) The subgenus Pachyconops is represented in California by two species, Pbysoconops gracilis Anal cell (Cu) much longer than second (Williston) and P. townsendi Camras. Pacbyconops basal (M) (Myopinae) (fig. 2a) ....4 is similar to the nominate subgenus, but differs in Anal cell (Cu) about equal to second basal having the front shorter than wide, and in having (M). 7 ............... the third antennal segment about equal to the Proboscis not geniculate at middle ...5 second. This subgenus to which twenty-five species Proboscis geniculate at middle.