Abstract: Autoparasitoids (heteronomous hyperparasitoids) are parasitoids whose males and females are parasitic in different species of hosts. Female eggs develop as obligate primary parasitoids, while male eggs develop as hyperparasitoids. The sex ratio of offsprings produced by females depending on the type of hosts is affected by host density, as well as the relative abundance of the primary and secondary hosts. Autoparasitoids can suppress the population of pests by parasitizing and feeding on the primary hosts. Also they can parasitize and feed on the hosts that have been parasitized by conspecific or heterospecific females, leading to the lethal interference competition. The window of secondary hosts for hyperparasitizing is at late instar larval to prepupal stage. Autoparasitoids prefer to hyperparasitize and feed on heterospecific hosts than conspecific hosts or have no obvious parasitization tendency. As a result, the specific reproductive pattern has led the application of autoparasitoids in biological control to become the focus of controversy. We should evaluate both the positive and negative influences caused by autoparasitoids before using it in biological control. In this article, we reviewed the recent advances on the reproductive traits of autoparaitoids, lethal interference competition effects on secondary hosts, and their influences on biological control. This will provide a theoretical foundation for the optimum use of autoparasitoids in integrated pest management.

Key words: Autoparasitoids, reproduction, sex ratio, secondary host selection, vulnerability window, host feeding, biological control