Bats provide valuable services in conventional apple orchards

Abstract

One-tenth of the global bat species is distributed in China, and 90 % of them are insectivorous. As a global leader in apple production, China's apple industry plays a vital role in boosting the income of local farmers. However, the role of insectivorous bats in suppressing apple pests and the resultant benefits to the apple industry have not been previously reported. This study investigated the dietary components of insectivorous bats, the relationship between bat activity and the abundance of prevalent insects, and the economic value of bat pest suppression services in apple orchards using DNA metabarcoding technology, acoustic monitoring, and exclosure experiments. The results showed that bats consumed various apple pests in multiple primary apple-producing regions. Moreover, bat activity was significantly and positively correlated with the abundance of the most prevalent insects. Finally, long-term exclosure experiments demonstrated that the presence of bats significantly reduced leaf herbivory and increased apple yield. Bats prevented a 4.2 % loss (897.556 kg/ha) in apple yield by preying on leaf-feeding apple pests. The economic value of the apple pest control services, which was estimated using the cultivation area, prices of apples, and exchange rate, was estimated to be ¥11.62–14.97 billion ($1.63–2.10 billion) annually. In conclusion, this study confirmed that bats prey on various pests, suppress leaf herbivory, and increase apple yield through the trophic cascade effects, providing economic benefits. Thus, these findings underscore the importance of integrating bat diversity conservation and ecosystem services into future integrated pest management strategies.