An expanded program of research on the cereal leaf beetle, Oulema melanopus (L.), in various north-central states has made it necessary to develop methods of rearing all stages of the beetle for laboratory use. Because the insect survives diapause in the adult state (Castro, 1964 and Connin, et al., 1968) it must presently be stored 10-12 weeks at 38 F before consistent oviposition is obtained. Hoopingarner, et al. \u27(1965) indicated that, while males are sexually mature in the prediapause condition, the female was unwilling to mate until after diapause and was not mature sexually until after mating.
More recent work by Bowers and Blickenstaff (1966) and Connin et al. (1967) indicated the possibility of breaking or eliminating diapause with chemicals. However, photoperiod also seemed influential in terminating diapause after varying periods of cold storage. The present paper reports observations on the photoperiodic effects