Egg of Aedes (Gymnometopa) mediovittatus (Diptera: Culicidae).

The egg of Aedes mediovittatus (Coquillett) is described from scanning electron micrographs. The egg is black, slightly tapered toward the posterior pole, and is approximately 771 microns long and up to 175 microns wide. On the entire egg surface there are about 970 polygonal outer chorionic cells, each bounded by a raised outer chorionic reticulum which forms a wall around each cell. Incorporated into the inner surface of this wall are 13-18 relatively small, poorly defined and variably shaped tubercles. In the center of each cell there is a large, buttonlike, more or less round tubercle with a pitted upper surface. Over most of the egg surface, the walls of this tubercle are connected by spokelike bridges of variable diameter to the cell floor or reticulum wall. The structure of the outer chorionic cells is somewhat modified in areas approaching the anterior and posterior poles.