Life history and immature stages of the parasitoid Microplitis mediator (Hymenoptera: Braconidae), reared on the bertha armyworm Mamestra configurata (Lepidoptera: Noctuidae).
Microplitis mediator [Microgaster mediator] is being considered for introduction into Saskatchewan to augment the biological control of Mamestra configurata, a pest of rape. It was reared in the laboratory on larvae of M. configurata. Notes on the life history of the parasite, and descriptions of the egg and 3 larval instars, are provided. Females of Microgaster mediator attacked the 1st 3 larval instars of the host; later instars were able to repel attacks by the braconid. Parasite development took up to 24 days. The 3rd-instar larva left the host (which died soon afterwards), and spun a cocoon in which to pupate.