Effects of Four Individual Pesticides and their Pairwise Combinations on the Survival and Growth of the Tadpoles of Two Anuran Species

Abstract

Environmental contaminants derived from pesticides could lead to a decline in wildlife populations and cause disruption of wildlife behavior, life history, and reproduction. Here, we have investigated the toxic effects of four pesticides, namely, chlorantraniliprole, penoxsulam, pymetrozine, and haloxyfop-P-methyl, on the survival and growth of the larvae of two anuran species, Fejervarya limnocharis and Microhyla fissipes. Our results showed that survival rates under most pesticide treatments (22/28) and growth under all pesticide treatments were lower than those under the control treatment. Mortality and growth reduction rates under treatment with pairwise combinations of pesticides were rarely higher than those under treatment with individual pesticides. At concentrations of 1 and 2 mg/L, the survival rates of F. limnocharis tadpoles did not drastically differ under treatment with all four individual pesticides. In contrast, the survival rates of M. fissipes showed significant differences under treatment with three of the four pesticides (except for pymetrozine). Our results suggested that individual pesticides and their combinations exerted different effects on organisms and implied the existence of pesticide- and species-specific toxicity effects.