Abstract

REPELLENT ACTIVITY AND SMOKE TOXIC EFFECT OF ZANTHOXYLUM RHETSA AND AMORPHOPHALUS SYLVATICUS AGAINST YELLOW FEVER MOSQUITO AEDES AEGYPTI

C. R. Hima*

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Abstract

A laboratory study was conducted to evaluate the repellent activity of Zanthoxylum rhetsa and Amorphophalus sylvaticus against the adult mosquitoes of Aedes aegypti. The ethanolic fruit extract of Zanthoxylum rhetsa at 100, 200, 300, 400 and 500 ppm offered 27.42, 48, 78.57, 91.42 and 100 percentage protection against mosquito bite during the time 5-6 p.m. The percentage protection against the mosquito bite was 25, 42, 71, 91.6 and 100 at 100, 200, 300, 400 and 500 ppm when treated with corm extract of Amorphophalus sylvaticus. Both of the results showed maximum percentage of protection in higher concentration (500 ppm) and minimum percentage of protection in lower concentration (100 ppm) during the time 5-6 pm, 6-7 pm, 7-8 pm and 8-9 pm respectively. After the smoke exposure of Zanthoxylum rhetsa coil the adult mortality of Aedes mosquitoes was 57.6 % where as in negative control (without plant ingredients) it was 0 % and in the case of positive control (synthetic coil) it was 50.4 %. In the case of Amorphophalus sylvaticus coil the adult mortality noticed after smoke exposure was 49.6 % where as in negative control (without plant ingredients) it is 0 % and in the case of positive control (synthetic coil) it was 46.0 %. From the above results it is clear that both Zanthoxylum rhetsa and Amorphophalus sylvaticus possess good smoke toxic effect and they can be used as effective repellents against Aedes aegypti.

Keywords: Zanthoxylum rhetsa, Amorphophalus sylvaticus, Aedes aegypti, Percentage of protection, Repellent activity.