Abstract
L. sericata, L. cuprina, Ch. rufifacies, C. stygia and C. augur have been bred through many generations in captivity. These flies were bred in artificial light as well as in sunlight. Inbreeding had no effect upon activity, fecundity or length of life.A diet of protein is necessary for the maturation of ova but not of spermatozoa.Oviposition is not strictly associated with a suitable larval environment, but is more in the nature of a response to a tactile stimulus. Copulation appears to provide an essential stimulus for oviposition.No evidence of parthenogenesis has been obtained and unfertilised females did not lay eggs.The maximum oviposition observed was 3,171 ova by a hybrid Lucilia. This fly lived 94 days.A total oviposition of 2,373 ova was observed in a L. sericata. Both parent flies lived 77 days.The number of ova a fly can produce at one time is dependent on its size and thus on the amount of food obtained in the larval stage.The sex-ratio for Lucilia is very close to 1 : 1. Starvation in the larval period did not have a marked effect on the sex-ratio.It is possible to cross the two closely related species of Lucilia, and the cuprina characters appear to be dominant. It is unlikely that this cross occurs in the field.