Abstract: Abstract: Host body size, one of host quality attributes, is often a major focus of the study of foraging behavior in parasitoid behavioral ecology. But little emphasis was placed on parasitoid body size. To investigate the effects of female body size on oviposition strategy in the gregarious parasitoid, Pteromalus puparum, experiments were conducted in laboratory under the stringent control of host (Pieris rapae pupae) body size to observe the oviposition behavior and examine the changes in the clutch size, sex ratio, and body size of the progeny parasitoids. The results indicated that the residence time of females on host pupae decreased with increase of their body size, but increased with host body size. Larger females gave birth to more offsprings with more eggs reserved after a bout of oviposition. Sex ratio and body size of offspring parasitoids were not affected by female body size, but the body size of female offsprings increased with host body size. The results confirm that female body size may affect part of the oviposition strategy in P. puparum, and should therefore be incorporated into models of oviposition strategies for gregarious parasitoids as an important variable.

Key words: Pteromalus puparum, clutch size, sex allocation, egg limitation, body size, fitness