Photoperiodic Control of Diapause Induction in the Larva of Lucilia Caesar L. (Diptera: Calliphoridae)

1. It has been shown that photoperiod has a direct effect on the larva of Lucilia casear L. in the induction of diapause. 2. Transference of larvae from long to short photoperiod conditions during the 1st, 2nd, or 3rd instar increases their tendency to enter diapause. Conversely, transfer from short to long photoperiod conditions decreases their tendency to enter diapause. 3. Larvae are sensitive to changes in the absolute length of the photoperiod during all instars. The reaction is not restricted to any one stage but tends to be cumulative; thus the earlier the larvae are transferred from one photoperiod regime to another then the greater the contrast in diapause incidence between experimental groups and controls.