Pre- and Post-Intervention Study on Aedes Larvae in Water Storage Containers Adding of Native Larvivorous Fish Aplocheilus panchax in Hpa-an Township, Kayin State

Abstract

Effective mosquito control strategies in temporary water storage containers in community are urgently needed to reduce dengue fever and dengue hemorrhagic fever through mosquito larvae reduction without harmful to environment, ecosystems and community. For biological control of Aedes aegypti larvae, native larvivorus fish as Aplocheilus panchax were collected from Hpa-an Township, Kayin State. Mingalar Ywar Thit and Taung Nar Village were selected as test and control villages and 51 households each were randomly selected to recruit the study. Laboratory and field study were done from February 2016 to January 2017. In the laboratory, a series of laboratory experiments compared Aedes larva consuming rates of Aplocheilus panchax and Trichogaster trichopterus in different water volumes, in order to determine their potential as larva control agent in water storage containers. In the field, Aedes larvae and pupae positivity in containers were recorded in both villages. During intervention, two Aplocheilus panchax were put into all major, minor and miscellaneous containers monthly for 3 months in test area of Mingalar Ywar Thit Village. Larval and pupal indices were determined before and after intervention. Laboratory result found that one gram weight of Aplocheilus panchax consumed 463.04 3rd and 4th instar Aedes larvae within 24 hours. It was 3.727 fold higher in consuming rate than one gram of Trichogaster trichopterus against 124.24 Aedes aegypti larvae. After intervention, House Index (HI), Container Index (CI) and Breteau Index (BI) were significantly reduced from 86.27%, 59.86% and 172.55 to 1.96%, 1.36% and 3.92, respectively (P<0.05). Hundred percent reduction was found in key containers and 90% reduction was found in key premises in test area. Pupal indices were also significantly reduced. Native larvivorus fish Aplocheilux panchax is an efficient biological agent for the control of DF and DHF vector Aedes immature stages in Kayin State. The biological method is simple and cost-effective method for control of DF/DHF in community.