Acoustic localisation of frog hosts by blood-sucking flies Corethrella Coquillet (Diptera: Corethrellidae) in Borneo

This study reports the occurrence of high diversity of novel frog-biting midges (Diptera: Corethrellidae) from Brunei Darussalam, Borneo. Flies were found feeding on eight species of frogs from five families. Traps using frog calls as lures were used to capture flies in lowland dipterocarp rainforest and peatswamp forest. We identified I I different fly morphotypes based on gross external morphology and pigmentation. Recognition tests showed that advertisement calls of three frogs, Ratio baramica Boettger (brown marsh frog), R. glandulosa Boulenger (rough-sided frog), and Megophrys nasuta Schlegel (Bornean horned toad) were sufficient for fly capture. The degree of host specificity using acoustic lures was weak. However, the proportion of different morphotypes caught at the traps broadcasting R. baramica and R. glandulosa calls differed, suggesting that frogs vary in their attractiveness towards frog-biting midges.