DNA Metabarcoding Reveals Insights into Diet Partitioning and Pest Suppression by Open Space Bats in Agricultural Landscapes

Open-space bats are abundant and common in agricultural landscapes, and widely recognized for their effectiveness as natural suppressors of pest insects. However, there is currently a lack of comprehensive studies on the diets and diet partitioning of these bats, particularly in terms of ingested pest prey species. Here, we explored the diet and diet partitioning of open-space foraging bats using DNA metabarcoding. We hypothesized that open-space bats residing near intensive agricultural areas would primarily feed on pest insects. Additionally, considering their shared guild and foraging habitats, we anticipated the occurrence of diet partitioning as a mechanism of reducing competition. Our results demonstrate the effectiveness of DNA metabarcoding in bat diet analysis, revealing a high diet diversity and enabling prey species identification. The outcomes exposed 1,557 OTUs and at least 36 agricultural pest species were found in the diet of these aerial insectivorous bats, including Nilaparvata lugens, Nysius graminicola, Piezodorus hybneri, Mythimna impura, Sesamia inferens, and Spodoptera frugiperda, among others. This finding underscores the crucial role of the studied bat species in pest control across a variety of crops such as sugarcane, rice, and corn, among others. We also observed evidence of diet partitioning. Mops plicatus primarily preyed on Hemiptera (Pentatomidae and Delphacidae). Taphozous theobaldi predominantly fed on Lepidoptera (Noctuidae and Erebidae). Taphozous melanopogon primarily fed on Lepidoptera (Noctuidae, Erebidae, Crambidae, Pyralidae, Geometridae). Scotophilus heathii focused on Coleoptera (Hydrophilidae and Tenebrionidae). Niche overlap was high between T. theobaldi and T. melanopogon, while T. theobaldi also moderately overlapped with M. plicatus. Mops plicatus had lower degress of overlap with T. melanopogon and S. heathii. The lowest degrees of overlap were observed between S. heathii and T. melanopogon, as well as between S. heathii and T. theobaldi. Thus, these bats exhibited niche diet partitioning at the family level. Our study highlights the occurrence of diet overlap and partitioning among open-space bats, underscoring their crucial role as effective pest suppressors in Asian agricultural regions. Their widespread presence, sizable population, and consumption of key pests, including migratory species, emphasize their significance in pest suppression. Protecting these bats is essential for suppressing pest insects and aiding farmers in protecting their crop yields across the region.