Exposure of tadpoles of Fejervarya limnocharis (Anura: Ranidae) to combinations of carbaryl and cypermethrin

Cypermethrin and carbaryl are both used to control pests of rice paddy crops but the two insecticides have different modes of action. In some areas or climates, the breeding of frogs living in rice paddy fields and the application of the insecticides coincide. The effects of the acetylcholinesterase (AChE) inhibitor carbaryl and the sodium channel blocker cypermethrin, both individually and in combination, were investigated on the survival and emergence of froglets of Fejervarya limnocharis using a 3x3 concentration factorial design (0, 25, and 50g L-1). Compared to controls, carbaryl showed no effect on survival and froglet emergence. Exposure to cypermethrin reduced the survival and froglet emergence in a concentration-dependent manner. When tadpoles were exposed to combinations of carbaryl and cypermethrin, the influence of carbaryl on survival and froglet emergence is less significant than that of cypermethrin.