Effect of Temperature on the Immature Developmental Time and Adult Longevity of Apanteles Galleriae Wilkinson (Hym. Braconidae)

Abstract

The greaterwax moth, Galleria mellonella (L.), is a known pest of the Egyptian and worldwide beekeeping. The solitary endoparasitoid, Apanteles galleriae Wilkinson is one of important natural enemies of the pest. The study aimed to determine the effect of temperatures under near-continuous darkness on the immature developmental time, growth of parasitized larvae and adult longevity of A. galleriae. The duration of developmental period of male was less than that of female irrespective of temperatures. At 20°C temperature and 75% RH, the duration ranged from 21.7 days for males and 23.8 days for females, decreased to 18.1 and 19.2 days at 25°C,17.1 and 18.1 days at 27°C and 16.0 and 17.3 days at 30°C, respectively. Parasitism by A. galleriae retards the growth of G. mellonella larvae. The initial weight of wax moth larva at the time of parasitization was 3.5±0.2 mg and was significantly lower (9.9±0.7 mg) prior to parasitoid egression than that of the non-parasitized larva (89.5±5.2 mg). The parasitized host larvae eventually weighed up to 70 to 88% less than the non-parasitized larvae. The adults survived starvation, water- or one -day honey feeding for few days, while they lived for significantly longer periods when they provided daily with pure honey. Longevity of females fed on pure honey was significantly longer than males at all tested temperatures. The results may be of value for developing mass rearing techniques and biological control of wax moths by A. galleriae.