The effects of diflubenzuron (DFBZ) on the activities of alkaline phosphatase (AKP) and acid phosphatase (ACP) in the fourth instar larvae of the mosquito Culex pipiens fatigatu were studied. The results showed that after cultivation of the larvae in water containing DFBZ of 0.01 ppm and 0.5 ppm their AKP activity declined markedly and may reach a 80% decrease. Their ACP activity was also depressed. The ACP activity of the untreated larvae would increase at the pre-pupation period, but the activity of the treated larvae decreased at that time. Presumably the decrease of phosphatase activities ...
