Genetic variation in insectary-produced and wild-caught biological control species Diglyphus isaea (Hymenoptera: Eulophidae) and Chrysoperla rufilabris (Neuroptera: Chrysopidae)

Biological control is an environmentally sound way to combat insect and mite pests. Many arthropod parasitoids and predators used in biological control are mass-produced in insectaries, distributed to clients, then released in a target area to control pest species. Abiotic and biotic conditions at release sites can often be different than those encountered in the insectaries in which these natural enemies are reared, thus generating concern about the adaptability of insectary-reared insects to different release conditions. Genetic diversity is frequently related to the ability of a population to adapt to novel environmental conditions. However, mass-produced populations risk a loss of genetic diversity. When individuals are collected to establish an insectary colony, they represent only a sub-set of the source population’s diversity. After remaining in isolation for many generations, diversity may be further narrowed by selective breeding, genetic drift, and inbreeding. In this study, we test this hypothesis by comparing the genetic fingerprint of field- and lab-produced populations of two biological control species: the haplodiploid parasitoid wasp, Diglyphus isaea (Hymenoptera: Eulophidae), and the diploid predator green lacewing, Chrysoperla rufilabris (Neuroptera: Chrysopidae). DNA extraction followed by AFLP analysis assessed the degree of genetic variation among populations. Our data did not find significant loss in variation between insectary-produced individuals and their wild-caught relatives of either species. Similarly, no significant differences in genetic variation were observed among insectary-reared populations in any of the two natural enemies studied.