Studies On Sophonia Spp.(hom.: Cicadellidae) And Their Natural Enemies

Sophonia leaihoppers originally distributed in Southeast Asia and southern China. They were inadvertently introduced to Hawaii in recent years and have caused severe damage to many agricultural crops as well as endemic plants. In order to find out the effective natural enemies in their native regions for biological control, the exploration and investigation of their natural enemies were conducted in Fuzhou from 1998. Studies on the population dynamics of Sophonia pal/ida (Melichar) on guava and Sophoniafurcilinea (kuoh et kuoh) on Acacia confusa in Fuzhou indicated that the 2 kinds of Sophonia leafhoppers occurred 3? generations per year. They keep developing without distinct overwintering and have overlapping generations. Nymphs occur 5 instars. In Fuzhou, the plant hosts of S. pal/ida included guava, soybean, peanut, sweet potato and hyacinth bean. When caged on the shoots of Acacia confusa, S. pallida could also feed and oviposit on them. In guava orchard, S. pallida would like to feed on sweet potato more than on other plant hosts in summer and fall. The plant hosts of S. furcilinea included Acacia confusa , guava, peanut, sweet potato and hyacinth bean. During August to October, the egg's mean development duration of S. pa//ida and S. furcilinea was 19.2 and 21 .8 days respectively. Three kinds of predators and eleven kinds of parasites have been found in Fuzhou. Among the 10 kinds of egg- parasitoids, Chaetomytnar sp. (Mymaridae) is the most abundant species which occupies 57.6% in the total parasites population. The egg percent parasitism in natural orchards is 50.6% in average, with a peak parasitism in September reaching up to 91 .4%. The parasitoid guild and percent parasitism varied depending on plant and on habitat.