Hymenopterous parasitoids of the exotic leafminers Liriomyza trifolii (Burgess) and Liriomyza sativae Blanchard (Diptera: Agromyzidae) in Shizuoka Prefecture, Japan.
The leafminers Liriomyza trifolii and L. sativae are exotic crop pests in Shizuoka Prefecture, Japan, and were first recorded in 1990 and 2001, respectively. From surveys conducted in the Prefecture between 1992 and 1994, seven parasitoid species were reared from L. trifolii, of which Neochrysocharis formosa and Chrysocharis pentheus were the most abundant. Surveys in 2004 and 2006 recorded 12 parasitoid species from L. sativae, and the most abundant parasitoids were once again N. formosa and C. pentheus. In both surveys, high female ratios were found in populations of N. formosa, suggesting that this species is parthenogenetic. Our surveys indicate that N. formosa and C. pentheus are the dominant parasitoid species of exotic invasive Liriomyza spp. and may play a key role in regulating their populations.