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 Dương 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 9th day to the 12th 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 13th 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 5th of study time, the soonest one was recorded from the Ma-SAT experiment on day 3rd.