Quantifying the Threat of Parasitoids in Large Scale Production Systems of Black Soldier Fly <i>Hermetia illucens</i> L

When the black soldier fly Hermetia illucens L. is reared in large numbers, three parasitoids were found to parasitise the pupae viz., Dirhinus sp. (Chalcididae); Trichopria sp. (Diapriidae) and Calyoza sp. (Bethylidae) causing severe depletion of culture in large scale production systems. Results showed that parasitisation was higher by Dirhinus sp than the other two and it ranged between 71.95± 2.36 to 76.30± 1.42%, followed by Calyoza sp. which parasitized between 5.99± 0.44 and 8.69± 0.20%, while Trichopria sp parasitized between 3.85± 0.14 to 6.93± 0.34%. Higher parasitization was noticed by Dirhinus sp. in large sized pupae compared to that in small sized pupae, while parasitisation by Trichopria and Calyoza sp. was not different between large sized and small sized pupae. Keeping these parasitoids physically out of the culture by covering trays with nets seems to be the only effective option in high volume production systems.