Fine Structure of the Eggs of Aedes Durbanensis, Aedes Woodi, and Eretmapodites Quinquevittatus (diptera: Culicidae)

Ultrastructural descriptions are given of the eggs of Aedes (Aedimorphus) durbanensis (Theobald), Aedes (Stegomyia) woodi Edwards, and Eretmapodites quinquevittutus Theobald). In Ae. durbanensis the egg is broadly cigar-shaped and all surfaces are uniform in structure. Chorionic cells are considerably longer (in the egg’ s longitudinal axis) than wide; each contains several relatively large, central tubercles with smaller peripheral ones closer to the chorionic reticulum. The egg of Ae. woodi is structurally typical of the subgenus Stegomyia, except that it is extraordinarily long in relation to width. Cells on the ventral (upper) surface are slightly longer than wide, and each contains a single very large, central tubercle surrounded by many much smaller ones. Pronounced structural change occurs transitionally down the lateral to the dorsal (lower) surface, where cells contain only small, low tubercles scattered over the cell floor. Eretmapodites quinquevittatus eggs also are long relative to width and structurally different on the ventral and dorsal surfaces. They are remarkable, however, in that the transitional change, with four structurally distinct longitudinal zones, is the most complex yet documented in a mosquito egg. Ventral surface cells contain a single, very large, round central tubercle with several much smaller ones abutted against the reticulum. Progressively toward the dorsal surface, these are replaced (laterally) by cells with several low, smooth, medium-sized tubercles, then (dorsolaterally) by cells with a few larger, domed, centrally clumped tubercles, and finally (in a middorsal band) by cells in which several small tubercles are scattered randomly.