ABSTRACT
The objective of this study was to evaluate the effect of pesticides on the pathogenicity of conidia of Lecanicillium lecanii, strain JAB 02, produced in culture media containing acaricides and insecticides, to the two-spotted mite Tetranychus urticae. A blend was made of insecticides (acephate, cyromazine, endosulfan, formetanate hydrochloride, imidacloprid, methiocarb, methomyl, monocrotophos, thiamethoxam) and acaricides (abamectin and propargite) in the culture media PDA, that was poured into a Petri dishes. After solidification, the fungus inoculation was realized at three points and the dishes were incubated for 16 days at a temperature of 25.5 ± 0.5º C and 12 hours of photophase. After the fungus growth, the colonies were cut out and removed to test tubes containing distilled water and detergent Tween 80Ò. The fungus suspension obtained for each treatment was standardized at 1 x 107 con./mL and 1 mL was sprayed on Canavalia ensiformis leaves. After the spraying, 15 mites were placed on each leaf disk and after 2, 4 and 6 days the mortality was evaluated in a stereoscopic microscope. The presence of acaricides and insecticides in the culture media did not affect the pathogenicity of conidia of L. lecanii, which on the 6th evaluation day presented a confirmed mortality in the range of 47 to 76% on two-spotted mites T. urticae.
KEY WORDS
Entomopathogenic fungus; selectivity; two-spotted mite; microbial control; compatibility