The effect of temperature on the relationship between wing length and body weight in a cohort of Anopheles quadrimaculatus was analyzed in a laboratory experiment. Mosquitoes reared at 23 degrees C were heavier and had longer wings than did those reared at 28 degrees C. In addition, even after differences in body weight were removed statistically, mosquitoes raised at 23 degrees C had longer wings than did those at 28 degrees C. The concordance of these results with those of a previous photoperiod study suggests that temperature and photoperiod experienced during development have some similar effects on the morphology of An. quadrimaculatus.