Bionomics of Elasmus japonicus (Hymenoptera, Elasmidae), a Parasitoid of a Paper Wasp, Polistes snelleni (Hymenoptera, Vespidae)

概要

論文の詳細を見る
A parasitic wasp, Elasmus japonicus, frequently infested pre-emergence and post-emergence nests of Polistes snelleni. It had at least two generations a year. Adults of the overwintering generation mainly attacked nests of P. snelleni during the pre-emergence stage, and adults of the later generation(s) attacked post-emergence nests. Larvae of the parasitoid externally fed on host immatures which had already spun cocoon. Mature larvae communally made fecal partitions in the cell before pupation to separate themselves from the host remnants. Workers and foundresses of P. snelleni usually removed cocoon caps of infested cells after the fecal partition was completed, though they sometimes killed the parasitoid larvae before that. Twenty to 29% of pre-emergence nests were parasitized by E. japonicus, and the loss in the number of workers owing to the parasitoid was estimated at 18 to 35% in three years. Parasitism levels reached 73 to 92% in post-emergence nests, which lost 17 to 22% of reproductives because of the parasitoid. Individual infested cells had means of 23 to 27 pupae of the parasitoid, with the sex ratio (proportion of males) varying from 0.04 to 0.75, though highly female-biased in most cells.
日本昆虫学会の論文
1994-06-25