PROC ENTOMOL. SOC. WASH. 100(4), 1998, pp. 658-664 NOTES ON THE HOST, EGG. AND PUPARIUM OF STYLOGASTER BIANNULATA (SAY) (DIPTERA: CONOPIDAE) Norman E. Woodley and Darlene D. Judd (NEW) Systematic Entomology Laboratory, PSI, Agricultural Research Service, U.S. Department of Agriculture, '^<: National Museum of Natural History. MRC-168, Washing-ton, DC 20560, U.S.A. (e-mail:
[email protected]); (DDJ) Department of En-tomology, Smithsonian Institution, MRC-169, Washington. DC 20560, U.S.A. Abstract. — The egg and puparium of Stylogaster hianniilata (Say) (Diptera: Conopidae) are described and illustrated in detail based on examination by scanning electron micros-copy. This species was reared from Grylliis nibens Scudder in Florida, a new host record. Previous literature is reviewed in light of this new data. Key Words: Stylogaster biannulata, Conopidae, hosts, egg, puparium, Gryllits rubens The genus Stylogaster Macquart has about 85 species distributed primarily in tropical regions in both hemispheres (Smith 1979: fig. 1 ). The greatest diversity is in the New World where 63 species occur (Cam-ras and Parrillo 1985), two of which are found in the Nearctic Region. This paper reports new data on hosts and immature stages for Stylogaster biannulata (Say) which occurs from Rhode Island to Ne-braska, south to Texas, Florida, and Vera-cruz, Hidalgo, and San Luis Potosi in Mex-ico (Camras 1965, Camras and Parrillo 1985). The other Nearctic species, S. neg-lecta Williston. is known from Massachu-setts to Nebraska, south to Arizona, Geor-gia, and Sinaloa and Chiapas in Mexico; its biology remains completely unknown. Hosts of Stylogaster The enigmatic biology of Stylogaster has been the subject of much speculation ever since Bates (1863: 365) published one of the first naural history observations of Styl-ogaster females hovering over advancing swarm raids of army ants of the genus Eci-ton Latreille. Early authors [see Aldrich (1930) for a good summary] were of the opinion that Stylogaster must have been us-ing army ants as hosts. Lopes (1937) found eggs of Stylogaster on an unspecified or-thopteran and a cockroach. Later observa-tions, particularly detailed ones by Retten-meyer ( 1 96 1 ), showed that the conopids were ovipositing on insects displaced by the advancing ants, as well as other insects, es-pecially tachinid flies of the genera Calod-e.xia Wulp and Androeuryops Beneway looking for hosts displaced by the ants. However, Rettenmeyer was of the opinion that cockroaches and possibly other orthop-teroid insects were the most likely hosts of Stylogaster. and eggs were inserted acci-dentally into tachinids utilizing the same hosts. He did, however, note (1961: 1015) that one of 17 Stylogaster eggs found on tachinids had initiated development, so he did not completely discount tachinids as hosts. Stuckenberg (1963), Smith (1967, 1969), and Smith and van Someren (1985) discussed the occurrence of Stylogaster eggs on various calyptrate Diptera, primar-ily Muscidae, in the Afrotropical Region. Some of these flies were associated with
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