Abstract
Microplitis manilae is new to Japan, and has been found to parasitize the larvae of Spodoptera litura in Okinawa Island, one of the southernmost islands of Japan. The parasitoids showed solitary endoparasitism and arrhenotokous parthenogenesis. They parasitized S. litura larvae from the first to antepenultimate instar, and greatly suppressed the feeding of host larvae, but they failed to parasitize penultimate and final instars, and eggs. Based on the developmental rates of M. manilae reared at constant temperatures between 15 and 30°C, developmental zero was calculated as 11.5°C and effective accumulative temperature from egg to adult emergence as 217.4 degree days. Oviposition and adult emergence of M. manilae were greatly suppressed when parasitoids were reared at a constant 15°C, while such suppression did not appear when they were reared at 15°C on average but at two different temperatures within a day. A female laid more than 300 eggs during 2 weeks of adult life at 20–30°C and survived for 60 days without egg laying at 15°C. The temperature dependency of development and fecundity in this species was compared with those of Meteorus pulchricornis, which is a well-known parasitoid of S. litura.
