FACTORS AFFECTING EGG MATURATION AND OVIPOSITION BY AUTOGENOUSAEDES ATROPALPUS(DIPTERA: CULICIDAE)

Abstract

Autogenous Aedes atropalpus (Coquillet) females derived from larvae fed on a standard maximum diet, matured about the same numbers of eggs when supplied with water only or with 25% sucrose. Those maintained on water laid 56% of the number matured within 5 days of emergence, but the sugar-fed insects laid only 28% in the same time, and even after 35 days many were found to have retained their eggs. The physiological mechanism causing the delay was not associated with crop distention, nor with the nutritional changes brought about by ingested sugar.Nulliparous females mostly refused blood during the first ovarian cycle although a few did rake a blood meal. At the time of feeding the eggs were already mature and neither the protein nor carbohydrate of the host blood were utilized during the first ovarian cycle. Parous females fed on blood and used the protein for egg development and there was a rapid rise in haemolymph carbohydrate after feeding, indicating that the host blood sugars also were used immediately.Nullipars derived from larvae maintained on a very low diet did not seek a blood meal either, and in these only some eggs commenced development to various stages. Sugar feeding by these adults assisted both maturation and oviposition.