In gregarious parasitoids such as Habrobracon hebetor, whose larvae feed collectively, they inevitably engaged in intraspecific competition. Therefore, due to the effects of competition, searching efficiency which is used to assess the parasitoid searching rates, might be reduced. In this study, the searching efficiency of H. hebetor wasps whose larvae were raised in competitive conditions (12 wasp larvae per each host larva) and non-competitive (one wasp larva per each host larva) were compared. Fourth instar flaxbudworm, Heliothis viriplace (Hufnagel, 1766) larvae with a density of 10 larvae per plant with random distribution were used for experiments. After larvae start to feed on on the host plant, four fertile female wasps were introduced to microcosm environments and after 48 hours, the number of parasitized larvae was recorded. The results showed that the searching efficiency of H. hebetor was 0.062 ± 0.002 in non-competitive situation which is significantly different with competitive searching efficacy recorded as 0.054 ± 0.001 (t = 3.02, df = 9, P = 0.014). Therefore, to obtain higher qualified wasps, it is better to provide them with enough host larvae in the insectarium to avoid competition.
