The Ovipositional Behavior in Euplectrus kuwanae CRAWFORD (Hymenoptera : Eulophidae), a Parasitoid of Argyrogramma albostriate (BREMER et GREY) : Lepidoptera : Noctuidae

概要

論文の詳細を見る
The ovipositional behavior of a gregarious external parasitoid, Euplectrus kuwanae, was studied in the laboratory. The parasitoid females began oviposition on the third day after emergence. An adult female attacked seven to nine host larvae for oviposition and laid an average of 96 eggs during its life time. However, the fecundity decreased considerably when the female parasitoid was given only already parasitized hosts. Number of eggs deposited on a single host varied with host size. When the host was large, 18 or more eggs were usually laid as a cluster by a female parasitoid; for a host lighter than 10 mg, on the contrary, the cluster size was as small as six eggs. The parasitoid had an ability to modify the sex ratio of the progeny according to the host size, i.e., the larger the host size, the larger the proportion of fertilized eggs to all the eggs laid by the female became. These abilities allowed E. kuwanae to utilize the host resources efficiently. When healthy and parasitized hosts were exposed to the parasitoid at the same time, the parasitoid sometimes attacked the parasitized host and destroyed the eggs existing on it before laying its own eggs.
1981-11-25