Species diversity and coexistence of mosquito larvae breeding in phytotelmata microhabitats; a cross-sectional study from Kalutara district, Western Province, Sri Lanka

Abstract

Phytotelmata are used by many insects for breeding. This study was designed to identify mosquito species breed in phytotelmata available in the Kalutara district. A larval survey was carried out once every two months from January 2019 to April 2021 in thirteen Medical Officer of Health (MOH) areas. For each survey, 20 premises including houses, institutions, public places, roadsides, open areas, and plantations were examined in one randomly selected Grama Niladari (GN) division in each MOH area. According to the study, 18 mosquito species belonging to 6 genera were identified in 8 types of phytotelmata namely; tree holes, bamboo stumps, leaf axils, tree trunks, fruit husks, fruit shells, fallen leaves, and fallen spathes. Species richness was highest in tree holes and species diversity was highest in fallen leaves. Similarly, 17 types of coexistence could be observed. The coexistence of four species Aedes chrysolineatus, Ae. downsiomyia, Ae. w-albus, and Ae. krombeini were observed in Dillenia suffruticosa fallen leaves. Species richness and species diversity of mosquitoes that breed in phytotelmata were highest in Walallawita. The correlation between the volume of water in phytotelmata and the number of larvae in the phytotelmata habitat was statistically insignificant. Although phytotelma is a hidden aquatic habitat, this study indicated that it is an important breeding place for a variety of mosquitoes including vector mosquitoes such as Ae. aegypti and Ae. albopictus.