Abstract
Larval rearing density had no effect upon adult female flight activity in Mythimna separata. M. separata females subjected to the dual stresses of crowded larval rearing conditions and flight over a 24 hour period, laid fewer eggs than females from solitary rearing conditions. M. pallens females showed no such fecundity changes.There was a positive linear relationship between pupal weight and fecundity which differed according to larval rearing density and flight treatments in both species. The differences are interpreted as allowing females to maintain relatively normal levels of fecundity following stresses (particularly weight reduction) associated with crowded larval rearing and prolonged flight. It is concluded that crowded larval rearing densities do not stimulate flight activity, and that both species may be equally capable of sustained flight.
