PROC. ENTOMOL. SOC. WASH. 106(4), 2004, pp. 811-825 ULTRASTRUCTURE OF THE CHORION OF DIOCTRIA FLAVIPENNIS MEIGEN, 1820 (DIPTERA: ASILIDAE: STENOPOGONINAE) COMPARED WITH THOSE OF FOURTEEN ASILID SPECIES FROM THE MID-ATLANTIC REGION OF NORTH AMERICA S. Candan, Z. Suludere, A. Hasbenli, N. ^agiran. R. Lavigne, and A. Scarbrough (SC, ZS, AH, NC) Gazi University, Faculty of Arts and Science, Department of Biol-ogy, 06500 Teknikokullar, Ankara, Turkey (e-mail:
[email protected]); (RL) P.O. Box 1010, Mt. Barker, SA 5252, Australia (e-mail:
[email protected]); (AS) Depart-ment of Biological Sciences, Towson University, Baltimore, MD 21252, U.S.A. (e-mail:
[email protected]) Abstract. — The fine structure of egg morphology of Dioctria flavipeniiis Meigen 1 820 was studied utilizing both scanning electron (SEM) and transmission (TEM) microscopy. Eggs from Aksaray, Turkey, averaged 0.4 mm in length and 0.3 mm in width and had a single micropylar opening at one end. Chorions were covered with small and large circular elevated structures. A micropylar region eclosion groove is reported for the first time. Sperm flagella were present in the micropylar region of some eggs. The endochorion and exochorion were distinguished from each other in TEM micrographs, the former being slighter more dense than the latter. Lamellar sheets, minute canals, and air ducts were also found. Additionally, the exochorion of the egg of D. flavipennis was compared with those (SEMs) of 14 asilid species from the mid-Atlantic region of North America: Ato-mosia puella (Wiedemann), Cerotainia albipilosa Curran, Eudioctha tibialis (Banks), Holcocephala abdominalis (Say), H. calva (Loew), Laphria divisor (Banks). L. flavicollis Say, L. ithypgi McAtee, L. sicula McAtee, L. virginica (Banks), Leptogaster flavipes Loew, Psilonyx annulatus (Say), Tipulogaster glabrata (Wiedemann), and Tohtrerus sp. Brief comments about the phylogeny of the egg chorion and its adaptation to various enviromental conditions are included. Egg morphology may be useful to elucidate taxo-nomic and phylogenetic relationships among asilids. Key Words: egg morphology, ultrastructure, chorion, Dioctria flavipennis, Asilidae, Dip-tera, SEM, TEM The taxonomic importance of egg mor-phology has become increasingly signifi-cant in a wide variety of insect orders, such as Diptera (Lounibos et al. 1997), Lepidop-tera (Salkeld 1983, 1984; Suludere 1988), Hemiptera (Javahery 1994), and Pleocop-tera (Szczytko and Stwart 1976, Starks and Stewart 1981). The surface structure of dip-teran eggs, as revealed by scanning electron microscopy (SEM), often provide reliable characters for separating species (Salkeld 1980, Kula 1988, Kuznetsov 1988, Linley and Chadee 1990, Sahlen 1990. Mouzaki et al. 1991. Feliciangeli et al. 1993. Greenberg and Singh 1995. Service et al. 1997. Sulu-dere et al. 2000a, b). Although an extensive survey of respiratory and morphological structures of insect eggs have been con-ducted by Hinlon (1981) and Margaritis (1985). little information concerning the
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