Egg morphology and stages of embryonic development of the glassy-winged sharpshooter (Hemiptera: Cicadellidae)

ABSTRACT The structure of the egg and embryonic developmental stages of glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Hemiptera Cicadellidae), an important vector of Xyhlla fastidiosa are described and illustrated. This sharpshooter has narrow, flattened elliptical eggs with the anterior end less broad and more pointed than the posterior end. The anterior portion of the egg contains a keel-shaped structure with a ridge that stretches backward for a short distance and then transforms into a groove stretching longitudinally along the ventral surface of the egg. The eggshell apparently has two layers: an outer shell layer that peels off easily when handling the egg, and an inner layer that appears intact, tightly surrounding the yolk and other liquid contents of the egg. There were six discernible stages of embryonic development (195 h at 25°C): an initial undifferentiated stage at 0–90 h, appearance of the head cap at 90–100 h, eye spot migration at 100–130 h, active physiological stage at 1...