EFFECT OF METARHIZIUM ANISOPLIAE ISOLATED FROM SOIL SAMPLES OF THE CENTRAL BRAZILIAN CERRADO AGAINST AEDES AEGYPTI LARVAE UNDER LABORATORY CONDITIONS

Abstract

The Larvicidal activity of Metarhizium anisopliae which originated from soil samples of the Central Brazilian Cerrado was tested on Aedes aegypti. Mortality of second instar larvae (L2) varied between 10 and 100%, 10 days after application of 5 x 1O conidiaJmi of 80 isolates. For some isolates, a sluggish behavior and accelerated mortality of L2 within few hours after treatment was observed. Larvae which had succunibed 24 hours after treatment were recovered with an elevated number of ungerminated conidia. A concentration of conidia was noted at the tip of the siphon and in the oral brushes of these iarvae. The aiimentary canal was generally repiete with ungerminated conidia. VariabHity of initial mortality, between 24 hours and 3 days, within replicates was noted for several isolates. Values of varied from 1.9 (IP 23) to 3.2 (IP 42) days and Li’91) from 2.8 (IP 84) to 7.8 (IP 76) days. Results showed that the M. anisoptiae isolates tested, which induced quick and high mortality, have potential for biological contrai of A. aegypti.