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 rufiventris parasitoid on the growth pattern of its teratocytes during the larval development is described as well as the changes in the number of these cells. The growth pattern of teratocytes derived from haploid eggs significantly differed from that of eggs deposited by mated females. Both cell diameter and the number of maturing M. rufiventris teratocytes was fertilization-dependent. Following the parasitization of Spodoptera littoralis larvae with virgin parasitoid females, the host larvae hosted a large number of cells of smaller size at the end of parasitoid development. The opposite effect was seen when the host larvae contained female parasitoid larvae. The age of the female at parasitization had an effect on the maximum cell size attained prior to parasitoid emergence. It seems that there are two factors other than mating which affect the number of teratocytes: degeneration inside the host haemolymph and to some degree accidental ingestion by parasitoid larva.