LABORATORY TRIALS OF Metarhizium anisopliae VAR. acridum (GREEN MUSCLE®) AGAINST THE SAXAUL LOCUST, Dericorys albidula SERVILLE (ORTHOPTERA: DERICORYTHIDAE)

The saxaul locust, Dericorys albidula Serville (Orthoptera: Dericorythidae) is a major pest of saxaul plants in Qom province of Iran. During 2005-2006, different nymphal instars of bands of D. albidula were treated by aerial spraying of Metarhizium anisopliae var. acridum (Green Muscle®). The gasoline formulation of M. anisopliae var. acridum isolate IMI 330189 was applied in different conidial concentrations (106, 107, 108, 109, 1010 and 1013 spores mL-1) that were prepared in sterile distilled gasoline. Results showed that various concentrations significantly affected the 2nd, 3rd, 4th and 5th nymphal instars of D. albidula compared to control. In addition, there were no differences in the effects of the different concentrations in 2005, but the differences were significant in 2006. Concentration 1010 killed 100% of tested insects 15 d after treatment. Comparing the results of the two years showed that the susceptibility of nymphs in the second year (2006) was higher than in the first year (2005). In conclusion, the results of this study indicated that the fungal insecticide M. anisopliae var. acridum, diluted in gasoline, was efficacious with the nymphal instars of locust D. albidula in 2005 and 2006