POTENTIAL OF FUNGI AS BIOCONTROL AGENTS OF POLYPHAGOTARSONEMUS LATUS (ACARI, TARSONEMIDAE)

Infection of broad mites, Polyphagotarsonemus latus, by conidia of Bea uveria bassiana, Hirsutella thompsonii, and Paecilomyces fumosoroseus conidia was investigated in the laboratory under controlled temperatur e and moisture conditions. Infection of P. latus by the fungus (LC50) was related positively to the 1.16 x 10(6) B. bassiana conidia per ml, 2.39 x 10(3) H. thompsonii conidia per mi, and 1.29 x 10(5) P. fumoso roseus conidia per mi. Mortality caused by B. bassiana occurred the fa stest among densities fluctuating between 65 and 125 mites per leaf. T he pathogens B. bassiana and P.fumosoroseus, adjuvants (oil and molass es), and the acaricide ABG6364, a microbial insecticide containing the Beta-exotoxin of Bacillus thuringiensis were evaluated for efficacy a gainst P. latus in a greenhouse test. The B. bassiana treated plants h ad the greatest and most persistent effect on percentage mortality of total broad mites present per leaf (88%) followed by the acaricide ABG 6364. Use of adjuvants (oil and molasses) did not increase infection o f P. latus.