Evaluation of smoke from mosquito coils containing Malaysian plants against Aedes aegypti

Nineteen mosquito coil formulations, each containing a different plant, were prepared and investigated for their knock-down and 24-h mortality values against Aedes aegypti Among them, only Azadirachta indica, Fernando adenophylla, Eurycoma longifolia, Aloe vera and Cymbopogon nardus showed moderate knock-down (KD) values, though the mortality values were insignificant. When D-trans-allethrin (0.01-0.1%) was added, the coils showed dose-dependent KD50, KD90 and mortality values. At 0.1% D-trans-allethrin concentration, the coils showed KD values comparable with those of a reference commercial mosquito coil containing a same amount of pyrethroid, while C. nardus coil exhibited significantly shorter KD values. The mortality values observed with coils of C. nardus, A. cera and A. indica containing 0.1% D-trans-allethrin were significantly greater than that of the reference coil. (C) 1999 Elsevier Science B.V. All rights reserved.