Entomological surveillance of container-breeding mosquitoes focusing on Aedes (Stegomyia) (Diptera: Culicidae) vectors along altitudinal range in Nepal.

Abstract

Mosquitoes are a significant public health concern due to their role in transmitting various diseases. This study aimed to investigate mosquitoes' diversity, abundance, and ecological aspects, mainly focusing on Aedes (Diptera: Culicidae) mosquitoes, in central Nepal. The research explored variations across regions, seasons, altitudes, and years. Fieldwork for mosquito collection was conducted between May 2022 and October 2023. Dipping and pipetting methods were employed to collect larvae and pupae, whereas Biogents-Mosquitaire trap captured adult mosquitoes. A total of 7,223 (3,640 larvae and 3,583 adults) mosquitoes, belonging to 8 genera and 18 species, were collected and analyzed. Additionally, a survey examined 5,941 wet containers of 20 different types to assess potential breeding sites. The study revealed Culex pipiens (Linnaeus, 1758) (34.13%) and Aedes albopictus (Skuse, 1895) (27.36%) as the most abundant species. Interestingly, larvae were predominantly Aedes spp. (66.13%), whereas only 13.76% of adults belonged to this genus. Mosquito abundance varied across locations and altitudes, with Siwalik region (331-700 m asl) exhibiting the highest numbers. The monsoon season showed the highest overall abundance (1,492). Used tires were identified as significant breeding sites for Aedes mosquitoes, and infestation rates were higher in shaded containers. Seasonal analysis showed the House Index (HI) reaching its peak (10.92%) and the Breteau Index (BI) reaching 23.08% during the monsoon. Conversely, the Container Index (CI) reached its highest point (37.67%) in the post-monsoon season. The results emphasize the need for comprehensive disease prevention strategies at local and national levels, including public awareness campaigns, to address mosquito-borne illnesses in this famous tourist region.