Predation effects of Lutzia vorax (Diptera: Culicidae) larvae on mosquito communities in treehole ecosystems in central Korean forests

Lutzia vorax Theobald (Diptera: Culicidae) is a ferocious predator of small container habitats in the forests and rural areas of the eastern Palearctic and Oriental regions. Owing to its consumption of various invertebrates, including mosquito larvae, it is considered a potential biological control agent of vector species. However, studies on the general biology of Lt. vorax are scarce; thus, our understanding of its role in natural habitats is limited. To elucidate its ecological role with regard to its interaction with vector species populations, we conducted field monitoring surveys in two different deciduous forests in South Korea, using tire traps for larvae in 2023. Community samples of mosquito larvae were collected every three weeks (July to September, 2023) from each trap, which replicated the natural container environment in forest areas. Then, community structures were compared based on the presence or absence of Lt. vorax. Communities with Lt. vorax larvae exhibited distinct structures characterized by lower species richness, diversity, and vector species density. Furthermore, non-metric multidimensional scaling results showed that the group structure differed depending on the presence of Lt. vorax larvae. Gut content analysis of the predaceous larvae supported the evidence of top-down regulation of Lt. vorax with considerable predation rates on other mosquito larvae in each habitat: 63.92 ± 30.72% in Site A and 72.85 ± 18.03% in Site B (mean ± SD). Thus, we suggest that Lt. vorax serves as both a significant natural enemy and key predator species in container habitats in the forested areas of Korea.