Fig. 2. Water loss rates in females of Culex pipiens over a prolonged period. Each point represents water loss determined as in Fig. 1. ND25, mosquitoes reared under a nondiapausing photoperiod (15 h:9 h, L:D) at 25°C; ND18, mosquitoes reared under a nondiapausing photoperiod at 18°C; D18, mosquitoes reared under a diapausing photoperiod (9 h:15 h, L:D) at 18°C. D18 to ND25 at 40 days indicates the mosquitoes were moved from diapausing (D18) to nondiapausing (ND25) conditions after 40 days, to break diapause.