ABSTRACT
This chapter considers the effects of mass rearing on the genetics of parasites and predators. If the mating system changes, e.g., with inbreeding or outbreeding, gene frequencies are maintained, but genetic arrays will change. A diversity of genotypes may be successful under particular conditions. A suggested cure for the genetic differentiation of laboratory colonies from native populations is the regular introduction of native individuals into the colony. Survival of the new colony depends upon the present laboratory environment and the way that the sample population gene pool responds to that new environment. Modem genetic theory suggests that natural populations of organisms, including parasites and predators, have enormous amounts of genetic variability. The erosion of variation by sampling or selection; the input of new genetic material by mutation or immigration; the protection of variation by mating patterns or cytological mechanisms.
