Species composition, relative abundance and seasonal variation of medically important mosquitoes in district Bajaur, Khyber Pakhtunkhwa, Pakistan

Abstract

Mosquito-borne diseases are a major public health concern. This study investigated mosquito species richness, relative abundance, and seasonal dynamics in District Bajaur, Pakistan. To assess the seasonal diversity and abundance of mosquitoes in District Bajaur and their potential role in malaria and dengue fever transmission. Adult and larval mosquitoes were sampled through standard collection methods, from multiple locations including cattle sheds, human dwellings, bathrooms, and animal bait. sampling was carried out from October 2023 to September 2024 according to WHO protocol. A total of 33,173 adult and 6303 larval mosquitoes, comprising five genera and 16 species were collected. Culex was the most dominant genus (63%), primarily Cx. quinquefasciatus (37%) and Cx. pipiens (25%). Aedes accounted for 20%, led by Ae. albopictus (13%) and Ae. aegypti (6%), while Anopheles comprised 16%, dominated by An. culicifacies (12%). Armigeres and Mansonia were rare. Indoor collections (26,580 mosquitoes) revealed higher abundance in cattle sheds, followed by human dwellings and bathrooms. Seasonal variation was evident, with peaks in July to August and minimal activity in winter. Cx. quinquefasciatus, Cx. pipiens, Ae. albopictus, and An. culicifacies were the most persistent species, present year-round and demonstrating ecological adaptability. Larval assessment confirmed strong seasonality, with peak abundance in August and no larvae detected in January. Statistical analyses revealed significant differences in the distributions across most species, though not in immature stages. Enhanced entomological surveillance during and after monsoon seasons is crucial for effectively controlling dengue, malaria, and similar mosquito-borne diseases.