Hemocytic studies on the synergistic effect of the entomopathogenic nematode species, Steinernema carpocapsae and gamma radiation on the greater wax moth, Galleria mellonella (L.) larvae

Abstract

Combined effect of substerilizing doses of gamma radiation (40 and 100 Gy) and different concentrations of the entomopathogenic nematode, Steinernema carpocapsae BA2 (20 and 40 IJs/ml) on the hemocyte count of the greater wax moth, Galleria mellonella (L.) larvae was studied. Eight types of hemocytes were described in the hemolymph of the normal larvae of G. mellonella. Prohemocytes were the predominant type, while the cystocytes were the rare ones. Morphological malformations and changes in the number of each hemocyte type were observed in F1 larvae (of irradiated male parent pupae with 40 or 100 Gy) or larvae treated with different concentrations of the S. carpocapsae BA2 (normal or F1 larvae); these alterations were increased by increasing the radiation dose or the nematode concentration that led to increase the susceptibility of the larvae to the nematode. Therefore, it could be concluded that integration of entomopathogenic nematodes and gamma radiation may serve as integrated control program for G. mellonella.