Studies on the Biology of Anagyrus dactylopii (Howard)

Anagyrus daclylopii (Howard) belongs to family Encyrtidae (Hymenoptera: Chcidoidae). It is an important endoparasitic natural enemy of Nipaecoccus vastator (Maskell) by means of mono-parasitic or multiparasitic ways. At about 22. 8℃, its one generation takes 20-22 days. The longevity of the female adults is longer than that the male ones. When the temperature ranges 20- 23℃, the mean longevities of the mated female and male adults are 4. 02 and 3. 42days respectively. The female and male adults fed on water and 25% honey juice can survive fairly well under natural conditions, but the female adults reduce their own longevity owing to the behaviour of seeking host and ovipositing. The female adults can reproduce either sexually or arrhenotokously. A mated female adult lays 21. 5 eggs in average while an unmated one gives only 8. 1 eggs. This wasp species parasitizes in the second and third instar nymphs and female adults of the host. The female adults superparasitize seriously. The orders of both superparasitic degree and egg-wasted status are all as: most serious in female adults of Nipaecoccus vastator, then in 3rd instar nymph, and in 2nd instar nymph regardless in choice or nonchoice conditions. The frequency of superparasitized hosts reduces with the increase of host density but the egg number in the parasitized host is no different significantly in different host densities.