Effect of landscape composition on frog communities and their role in biocontrol of rice pests

Abstract: Frogs are generalist predators of arthropods in rice fields, and may potentially act as biocontrol agents of rice pests. This would justify targeted conservation actions, including measures at landscape level. However, comprehensive, quantitative studies are still lacking on how landscape composition affects frog abundance and diversity, and the role of frogs in the suppression of rice pests. We studied the effect of landscape composition on rice frog abundance and species diversity, and the relationship between frog abundance and natural enemy abundance, pest abundance, yield and yield loss in rice across 19 landscapes during two years. Frog abundance was positively associated with water, while frog diversity was positively associated with forest and double-cropping rice. The abundance of rice pests and their natural enemies were negatively associated with frog abundance, indicating that frogs can have an important impact on arthropod communities in rice. However, frog abundance was not significantly associated with rice yield and yield loss. Our findings indicate that the role of frogs as biocontrol agents is inconclusive because their impacts on both rice pests and their natural enemies. However, given their overall suppressive impact on arthropod abundance, frogs may contribute to the overall stability of rice field ecosystems.