Influence of food on the longevity and egg maturation of the egg parasitoid Ooencyrtus nezarae (Hymenoptera: Encyrtidae)

Ooencyrtus nezarae is a parasitoid wasp attacking eggs of several pest Hemiptera in soybean fields, and plays an important role as a main natural enemy of soybean pests. However, many aspects of the biology of the parasitoid remain unknown. Laboratory experiments were carried out to study the influence of food for adult females on the longevity and egg maturation of O. nezarae. The mean longevity of the females provided with honey throughout their life span was 40.4 days and was significantly longer than that of females provided with limited food (honey for one day) (means: 5.5 days), water only (3.0 days) or control (2.0 days). The total number of eggs matured within 3 days by honey fed females was 15.9 and was significantly higher than that by one-day honey fed (11.0 mature eggs), water fed (3.0 mature eggs) or control (0 mature egg) females. The present study suggests that life expectancy is extremely limited if the females cannot obtain carbohydrate sources continuously during the adult lifetime. Also, egg maturation is largely restricted under poor food conditions. Thus, the availability of food for adult females should determine the reproductive success of O. nezarae.