PROC. ENTOMOL. SOC. WASH. 92(3), 1990, pp. 497-511 FINE STRUCTURE OF THE EGGS OF PSOROPHORA COLUMBIAE, PS. CINGULATA AND PS. F£/?O.Y (DIPTERA: CULICIDAE) John R. Linley' and Dave D. Chadee-' Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th Street S.E., Vero Beach, Florida 32962; -Insect Vector Control Division, Ministry of Health, 3 Queen St., St. Joseph, Trinidad, West Indies. Abstract. —The eggs of Psorophora columbiae, Ps. cingnlata and Ps.fewx are described with reference to scanning electron micrographs. In contrast to earlier descriptions, com-plete details of the Ps. columbiae and Ps. fero.x eggs are given, including the anterior end and micropyle, posterior end, and intact outer chorion. This is the first account of the egg of ft. cingulata. Eggs of Ps. fero.x from Florida are discemibly different from a Trinidad population in terms of the number and form of the small outer chorionic tubercles in each chorionic cell. Key Words: Insecta, mosquito, egg, fine structure, chorionic structure The known distribution of Psorophora (Grabhamia) cingulata (Fab.) extends through Trinidad, possibly Central America and much of South America (Knight and Stone 1 977). It is a species about which little is known, except for a number of records of the larval habitat (Heinemann et al. 1980). Its egg is described here for the first time. Psorophora (Janthinosoma) ferox (von Humboldt) is a very widespread species, ranging from South through Central Amer-ica, the Greater and Lesser Antilles, the eastern United States and south-eastern Canada. The egg of this species was first described by Horsfall et al. (1952), from eggs stripped of the outer chorion. Subsequently, using eggs prepared in the same way, Hors-fall et al. ( 1 970) published scanning electron micrographs showing the inner chorionic sculpturing. Although eggs lacking the outer chorion are adequate to demonstrate the ba-sic outline pattern of the outer chorionic cells, the entire structural detail of the outer chorion is lost. In this paper we provide the first description of the intact egg, including details of the posterior end and anterior end and micropyle. The description is based on eggs from Ps. ferox collected in Florida, but we also describe and illustrate differences in eggs from a Trinidad population. In their papers cited above, Horsfall and associates described (as Ps. coufinnis) the egg of ft. (Grabhamia) columbiae (Dyar and Knab). Their material was collected from the eastern United States, which would im-ply that it is ft. columbiae as currently rec-ognized (Belkin et al. 1 970, Darsie and Ward 1981). Bosworth et al. ( 1 983) examined ft. columbiae e^^ in more detail as part of their study of eggs of the ft. coufinnis complex from 7 areas of the country. However, as in the work by Horsfall and co-workers, the outer chorion was first removed, then the sculpturing of the inner chorion in the an-terolateral part of the egg was compared by scanning electron microscopy (SEM). None of these studies, therefore, has presented a description of the egg in its natural form (outer chorion intact), or of all its parts. Fol-lowing the more complete account in this
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