Photoperiod and longevity in Anopheles crucians.

The effect of photoperiod on longevity of nondiapausing members of Anopheles crucians was evaluated in laboratory experiments. First-generation adults reared from field collections illustrated the same trends. Individuals reared and maintained under short photoperiod (either 8 h light:16 h dark or 11 h light:13 h dark) lived longer than did those reared and maintained under long photoperiod (either 16 h light:8 h dark or 15 h light:9 h dark). Analysis of covariance showed that the greater longevity of short-photoperiod mosquitoes was not caused by their larger average body size. Also, a paired t-test confirmed the effect of photoperiod, independent of body size, on longevity; in mosquitoes paired according to thorax length, short-photoperiod individuals lived longer than did long-photoperiod individuals of the same sex and cohort. The reason short-photoperiod mosquitoes of this species live longer is not known.