SCREENING THE ABILITY TO CONTROL MESOMORPHUS VILLIGER (BLACK BEAN BEETLE) OF SIX METARHIZIUM ANISOPLIAE STRAINS ISOLATED IN BINH DUONG, VIET NAM

Three types of bio-preparations of six different Metarhizium anisopliae strains (Ma-SD, Ma-SAT, Ma-ST, Ma-RS, Ma-RN, and Ma-RM) isolated from soil in Binh DÆ°Æ¡ng province, Viet Nam, including conidia, LIMs and MIXs, were evaluated the acaricidal effects on Mesomorphus villager (Black bean beetle). The results of conidia studies showed the high efficacies of Ma-SAT and Ma-ST at 98.64 ± 1.25 percent and 95.23 ± 3.15 percent, in turn. The times to kill half of the studied beetles were observed from the 9^th day to the 12^th day of the 15-day study process seemed indifferent and late, also without signs of mycosis at the end of the studies. LIMs had low efficacies in the studies, though the LIM of Ma-SAT continued to perform the efficacy at 57.14 ± 3.45 percent among the studied groups after the 15-day study process, moreover, its LIM was the only one killing half of the beetles on day 13^th of the study process. The efficacies of MIXs were all higher than 91 percent, among them, Ma-ST, Ma-SAT, and Ma-RS showed their outstanding performance at 96.94 ± 2.49, 98.08 ± 1.21, 98.18 ± 1.38, respectively. Interestingly, all strains were observed to kill half of the studied beetles on day 5^th of study time, the soonest one was recorded from the Ma-SAT experiment on day 3^rd.