AN ENZYME FROM MYROTHECIUM-VERRUCARIA THAT DEGRADES INSECT CUTICLES FOR BIOCONTROL OF AEDES-AEGYPTI MOSQUITIO

Myrothecium verrucaria produced a high activity of extracellular insec t cuticle degrading enzymes, chitinases, proteinases and lipases. Both first (I) instar and fourth (IV) instar larvae of a mosquito, Aedes a egypti, a vector of yellow fever and dengue, were susceptible to crude culture filtrate (100% mortality within 48 h at 170 mg/l). The supple mentation of purified M. verrucaria endo-chitinase with commercial lip ase decreased the lethal time (LT(50)) from 48 h to 24 h for I instar and 120 h to 96 h for IV Instar. Our results of the larvicidal activit y indicate that the cuticle degrading enzyme complex of M. verrucaria has a good potential for the control of mosquitoes.