temperature-dependent development of habrobracon hebetor (hym.: braconidae) reared on larvae of galleria mellonella (lep.: pyralidae)

the development times and the survival rates of different stages of habrobracon hebetor say reared on the last instar larvae of galleria mellonella (l.) were compared at ten different constant temperatures (16 - 38 âºc). the development time of immature stages of the parasitoid, h. hebetor, decreased as the temperature increased in the range of 16 to 38 âºc. however, no larvae could survive and develop at 16 âºc. development time from egg to adult females was the shortest (8.368 â± 0.069 days) at 35 âºc and the longest (32.667 â± 0.33 days) at 18 âºc. egg incubation period, larval and pupal development times were significantly different at various constant temperatures. no significant difference was found between two sexes in their developmental periods from eggs to adult stage. the survival rate of the egg stage ranged between 94.90 and 100% at all temperature levels, but larval survival rates was significantly different at various temperatures. although significant difference was found in the survival rate of pupal stage (p < 0.05), the trend of survival rate for pupae was similar to those of larvae. the relationship between temperature and the developmental rate of the parasitoid well described by linear regression model (r2 = 0.89, p = 0.0001, at the egg stage and r2 = 0.95, p = 0.0001, at the egg-adult stage). the lowest threshold temperature was obtained for all developmental stages of the parasitoid. degree-days requirements (dd) for egg, larva, pupa and egg-female stages were 22.73, 56.82, 109.89 and 188.68, respectively. the results in this study showed that the temperature range between 25 and 32 âºc provide a favourable condition for mass rearing of this parasitoid.