Control of the Lesser Grain Borer (Rhyzopertha Dominica (F.), Coleoptera: ‎Bostrichidae) By Treatments with Residual Formulations of Metarhizium Anisopliae ‎‎(Metschnikoff) Sorokin (Deuteromycotina: Hyphomycetes)‎

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Journal Title, Volume, Page: 
Journal of Stored Products Research, Volume 41, Issue 2, Pages 221-229
Year of Publication: 
Y.A. Batta
Laboratory of Plant Protection, Department of Plant Production and Protection, Faculty of Agriculture, An-Najah National University, Nablus, Palestine
Current Affiliation: 
Department of Plant Production and Protection, Faculty of Agriculture and Veterinary Medicine, An Najah National University, Nablus, Palestine
Preferred Abstract (Original): 

Treatments with conidia of the entomopathogenic fungus Metarhizium anisopliae formulated in invert emulsion (water-in-oil formulation) or in wheat flour were applied to Rhyzopertha dominica adults infestingCicer arietinum grains. The application rates were 4.1×105 conidia/cm2 of treated area using a concentration of 1.8×107 conidia/ml of the invert emulsion and 8.2×106 conidia/cm2 of treated area using a concentration of 6.5×108 conidia/g of the wheat flour formulation. Results have indicated significant mortality (P<0.05) when newly emerged Rdominica adults were introduced and then treated with the invert emulsion and wheat flour formulations (86.7–93.3%, control treatment 10.0–26.7% mortality). When treated grains were left until the emergence of F1 adults, there was also significant mortality (P<0.05) in both treatments (28.3–60.0%, control treatment 1.7–8.3% mortality). This indicates a residual effectiveness of the treatment with the two formulations against Rdominica adults which extended to >2 months (equivalent to the duration of the insect life-cycle at 23±2°C and 75±5% r.h.). Infestation rate of Carietinum grains by Rdominica at 23±2°C and 75±5% r.h. was significantly reduced in the treatments with the fungal conidia formulated in invert emulsion (0.7%) or in wheat flour (1.0%) when compared with the control treatment (19.0–23.3%). The preventive treatments significantly retarded Rdominica development (P<0.05) by 8–12 days compared with the control treatment. The infection with the fungus thus delayed adult emergence of Rdominica by 8–12 days. Overall results give promise for control of Rdominica with Manisopliae mixed with wheat flour or introduced into invert emulsion.