Adulticidal Activity of <i>Combrentum micratum</i> leaf extract against Female An. gambiae (<i>Culucidae: Diptera</i>)

Abstract

Adulticidal activity of Combrentum micratum was carried out against Anopheles gambiae. Combretum micratum leaves were obtained from Goron-maje  town, Dambatta Local Government Area in Kano Nigeria State. The prepared test concentration of plant extract was volumetrically diluted in methanol  solvent using standard method. One (1) mL Combretum micratum was diluted in methanol and prepared using 2, 4 and 6% concentrations respectively .  Each test concentration was repeated four (4) times and each replicate was subjected to different volunteers to nullify any effect of repellent on their kin.  Volunteers were asked to follow the testing protocol. The World Health Organization (WHO) recommended percentage protection in relation to  concentration and method was used. Combretum micratum extracts was evaluated for their repellent activities against adult female Anopheles gambiae     using the human bait technique. The results showed that C. micratum had adulticidal activity against Anopheles mosquitoes tested with strong repellency  actions on volunteers A, B, and C with complete protection time (CPT); A (30.73%), B (33.33%) and C (16.66%) when compared to the control  employed. For all the treated groups, methanol extract showed low biting activity compare to control with highest biting deterrence recorded for each  concentration 0.2mL, 0.3mL and 0.4mL respectively. The findings in this study has revealed that the extracts from the leaves of C. micratum possessed  potent effect on repellency against adult female Anopheles mosquitoes and may therefore serve as a potential source for the control of adult mosquitoes