Effect of mating status and age of Microplitis rufiventris (Hym., Braconidae) females on the growth pattern and number of their teratocytes

The effect of mating status and age of the female of Microplitis rufiventri s parasitoid on the growth pattern of its teratocytes during the larval dev elopment is described as well as the changes in the number of these cells. The growth pattern of teratocytes derived from haploid eggs significantly d iffered from that of eggs deposited by mated females. Both cell diameter an d the number of maturing M. rufiventris teratocytes was fertilization-depen dent. Following the parasitization of Spodoptera littoralis larvae with vir gin parasitoid females, the host larvae hosted a large number of cells of s maller size at the end of parasitoid development. The opposite effect was s een when the host larvae contained female parasitoid larvae. The age of the female at parasitization had an effect on the maximum cell size attained p rior to parasitoid emergence. It seems that there are two factors other tha n mating which affect the number of teratocytes: degeneration inside the ho st haemolymph and to some degree accidental ingestion by parasitoid larva.