Larvicidal activity of medicinal plant extracts against Culex quinquefasciatus Say. (Culicidae, Diptera)

摘要

Mosquito is a vector of different diseases like Malaria, Filariasis and Dengue fever. It has been increasing development of resistance to synthetic chemicals, so plant extracts may be the alternate source of mosquito control agent. This study was conducted on five different plant extracts as Nicotiana tabacum, Ocimum basilicum, Datura stramonium, Chenopodium album and Cassia fistula against Culex quinquefasciatus Say. to evaluate them as an efficient larvicide potential. Plant extracts offered a virtually untapped chemical compounds with different potential uses. Study was focused on laboratory determination of LC 50 and LC 90 values by a bioassay test. These plant extracts were tested on 3 rd instar of mosquito larvae. The plant extracts were applied with different concentrations as 400, 200, 100, 50, 25 ppm with acetone as control and mortality was counted after 24, 48 and 72 hours. The efficiency of plant extracts was recorded in term of % age mortality. From these extracts Cassia fistula gave 100% mortality and Nicotiana tabacum gave 98% mortality after 72 hours of application. In sense of LC 50 and LC 90 values Cassia fistula showed 50.272ppm and 203.994ppm respectively. LC 50 and LC 90 values of Nicotiana tabacum were 17.772ppm and 206.485ppm respectively.