Diversity of mosquito natural enemies and their feeding efficacy on Aedes vectors.

Background objectives: Mosquito-bome diseases are a major health issue among communities in Asia, and dengue has become a serious public health concern in Sri Lanka with varying magnitude since 1960. With the realization of the failures and limitations of current vector control strategies, the authorities are moving towards simple, low- cost, and eco-friendly vector management methods. Thus, the present study was devised to evaluate the potential densities of mosquito natural enemies in natural water habitats in Galle district, Sri Lanka, and to investigate the feeding efficacy of prominent mosquito natural enemies on main dengue vectors (Aedes sp.) in a laboratory setting.

Methods: The survey was carried out using eight sentinel sites in Galle district, and samples of mosquito natural enemies and mosquito larvae were collected, and identified using taxonomic keys.

Results: Study records, the aquatic insects of family Hydrometridae, Belostomatidae, Notonectidae, Nepidae, Ranat- ridae, and Corixidae as dominant mosquito natural enemies, and Libellulidae and Dytiscidae insects as sub-dominant families. The highest density of the family Hydrometridae was recorded in rural, natural inland, and rocky study sites. The order Hemiptera was recorded as the key order of the mosquitos' natural enemies in Galle district. The family Hydrometridae had the highest density of recorded mosquito natural enemies.

Interpretation conclusion: Aedes aegypti and Ae. albopictus were recorded as abundant vector mosquitoes. Family Nepidae is the most effective natural mosquito predator on Ae. aegypti and Ae. albopictus, and this knowledge will be vital for implementing future biological control strategies for Aedes vectors in Sri Lanka.