author(s)
M Suresh, L Premraj and JMV Kalaiarasi

abstract
The present study was conducted to test the bioefficacy and larvicidal activity of Couroupita guianensis (Aubl) against housefly, Musca domestica (L). The concentration range used was 62.5, 125, 250 and 500 ppm. Leaves of C. guianensis were collected from Loyola College Campus, Chennai, Tamil Nadu, and India during August to December 2016. The plant leaves were dried and coarsely powdered. The plant materials were sequentially extracted with increasing polarity of hexane, chloroform ethyl acetate, and methanol. The dried leaves were pounded mechanically using commercial electrical stainless steel whizzer and extracted using hexane, petroleum ether, chloroform and ethyl acetate, in a soxhlet apparatus (boiling point range: 60°–80 °C) for 8 h separately until exhaustion. All the extracts were concentrated using rotary vacuum evaporator. The residues were weighed and preserved in airtight bottles at 4 °C until further use. The larvicidal activity of the different solvent extracts such as hexane, chloroform, ethyl acetate & methanol of Couroupita guianensis were evaluated. The result of this work revealed that the larvicidal effects of the leaf extract of Couroupita guianensis on the early third instar larvae of Musca domestica were dependent on the concentration of the extracts at 62.5 to 500ppm. Among the extracts ethyl acetate extract of C. guianensis presented promisable larvicidal activity with LC₅₀ and LC₉₀ values of 479.137 and 1969.851ppm against the larvae of Musca domestica, respectively. Naturally occurring medicinal plant extracts of Couroupita guianensis and leaf-derived compounds merit further study as potential housefly larval control agents or lead compounds.