Ovary Development and Oviposition Rates in the Plum Curculio, Conotrachelus nenuphar (Coleoptera: Curculionidae)1

Abstract

The stages of ovary development and oogenesis in Conotrachelus nenuphar (Herbst) are described in this study seeking guides to the oviposition potential of naturally occurring females. In the vicinity of Geneva, N. Y., summer brood adults emerge from July to October and feed for a time; the females are unmated when they enter hibernation and oogenesis has not been initiated. When the adults emerge from hibernation, oogenesis has begun in about half the females. The beetles appear in the host trees at about the time when apples reach full bloom; mating occurs as they congregate in the host trees, and maturation of eggs is completed in most females by the petal-fall stage. Under natural conditions oviposition continues for about 4 weeks, and for several weeks thereafter mature eggs and oocytes are present in the females. These are reabsorbed, and no longer are a distinguishing feature of overwintered females. These females can be distinguished from those of the current brood by the presence of sperm in the spermatheca.