Rate of Parasitism of the Antlion Larvae, Myrmeleon bore (Neuroptera : Myrmeleontidae) by the Bee Fly, Villa myrmeleonostena (Diptera : Bombyliidae)

The bee fly, Villa myrmeleonostena parasitize the antlion larva, Myrmeleon bore living in seaside dune. To obtain the ecological information on the parasitism by V. myrmeleonostena, we examined rates of parasitism in the antlion larvae collected monthly from April to October in 1991. Adult bee flies emerged from cocoons, which we obtained by rearing the antlion larvae. The emergence times of parasitoids and hosts were similar. The parasitism rate based on pooled data was the highest in the third instar larvae (9.7%) and the lowest in the first instar larvae (2.5%). More than 15% of third instar larvae collected in April and May were parasitized by V. myrmeleonostena. Newly hatched first instar larvae of M. bore were found after August, and some of them were also parasitized. From these results, it was inferred that V. myrmeleonostena oviposit during the period from late summer to mid-autumn. They probably do not touch an antlion larva to lay an egg on it but might drop an egg while hovering around the pit of antlion.