Palm wines as potential Aedes mosquito repellant

Globally, Aedes mosquitoes cause morbidity and mortality of dengue, yellow fever and other arboviral infections. There is no effective vaccine for Aedes transmitted diseases so mosquito control remains the mainstay for their control. Semiochemicals play significant role in modulating insect behavior so are utilized to lure mosquitoes to their destruction or to repel them to halt infection transmission. Palm wines are potent source of semiochemicals but their effect on Aedes mosquitoes in our locality is not well understood. This study was undertaken to ascertain whether palm wine could impact on mosquito inflections. Aedes larvae were collected and bred in the laboratory to adulthood. Female mosquitoes were selected and tested for their reactions to two categories of palm wine – the up-palm and down-palm wines. An olfactometer was fabricated and applied to find how Aedes mosquitoes reacted in it when subjected to odours from the palm wines within 5 minutes. Data obtained were prepared and one way analysis of variance was used to compare means. Only 3% of mosquitoes reached the up-wine arm on day 2. However, when both wines were tested, 2.78 ± 2.78% of mosquitoes reached the down-palm wine terminal. Both wines repelled mosquitoes consistently, confirmed by their refusal to seek any of the palm wine odours. Repellence increased as days passed: initially upstream mosquitoes ranged 36.36 – 60% at the beginning, declining to 3.3 – 6.36% on the 8th day; whereas downstream ranged from 40 – 63.63% at the beginning to reach 93.63 – 100% on the 8th day. Palm wines semiochemicals repelled Aedes mosquitoes. Further testing may be required before utilization in formulated repellents for public use.

 Ugwu Francis Stephen Ogbonna and Onyemeziri Patrick Chibueze