小菜蛾幼蟲寄生小繭峰(Apanteles plutellae)之重複寄生蜂

Abstract

Apanteles plutellae Kurdj., Braconidae, has been considered an effective larval parasitoid of the diamondback moth (DBM), Plutellae xylostella Linn. (Plutellidae) in Taiwan. It was mass-reared and released to vegetable growing areas viz. Shilin, Chupei, Hsilo, Yungchien, Nantyu, and Luchu in 1972 and 1973 for the biological control of DBM. This paper report the species and some biological information of the hyperparasitoids of A. plutellae in Taiwan. A total of 10 species of hyperparasitoids of Apanteles plutellae were reared from 10,770 cocoons of Apanteles plutellae. They are Diatora prodeniae, Gelis sp., Stictopisthus sp. (Ichneumonidae); Brachymeria sp. (Chalcididae); Eurytoma sp. (Eurytomidae); Trichomalopsis apanteloctena, T. shirakii, Trichomalopsis sp. (Pteromalidae); Elasmus sp. (Elasmidae); and Calliceras sp. (Ceraphromidae). Three species of them, viz. T. shirakii, Calliceras sp. and D. prodeniae were successfully inoculated to the cocoons of Apanteles plutellae in laboratory. The females of T. shirakii and D. prodeniae were observed not only ovipositing to A. plutellae but also feeding upon host body-fluids and caused the death of host. Percentage of hyperparasitism were recorded about 26.3% in the insecticides spraying fields, about 46.2% in the harvested fields, and about 3.1% during the initial period of A. plutellae cocoons appeared in the non - insecticides spraying screened house. The hyperparasitism in the screened house was high up to 53% after 75 days of A. plutellae cocoons were firstly occurred.