Insect species collected in the old nest of marsh-dwelling raptors (Eastern Marsh Harrier) in south-western Japan

Abstract

We collected an old nest of the Eastern Marsh Harrier Circus spilonotus, whose chicks had fledged more than 78 days prior to the collection, from a reed field within a salt marsh in October 2022. We found 14 species of insects belonging to 6 orders and 9 families in the old nest. Among these, the most abundant species were Scotinophara horvathi (Hemiptera, Pentatomidae), Oncocephalus femoratus (Hemiptera, Reduviidae), Pristomyrmex punctatus, and Camponotus vitiosus (Hymenoptera, Formicidae). At least the former three species are typically found near the dry ground surface, despite the fact that the environment at the collection site of the nest was a wetland with no dry surface within 45 meters. In such wetland habitats with limited ground availability, old nests of the Eastern Marsh Harrier may serve as a "rare, micro-ground surface" for these insects.