Submitted to: Arthropod Management Tests
Publication Type: Research notes
Publication Acceptance Date: 2/1/2007
Publication Date: 6/1/2007
Citation: Tharp, C.I., Blodgett, S.L., Jaronski, S. 2007. Control of wireworm (elateridae) in potatoes with microbial metarhizium. Arthropod Management Tests. Vol. 32 #E43. Interpretive Summary: The insect pathogenic fungus, Metarhizium anisopliae strain F52, is under development for the control of a number of soil-dwelling insect pests. Its efficacy against larval wireworms in potatoes was evaluated in small plot field trials at two sites in Montana in 2006. Several different formulations of the fungus were applied at planting. No statistically significant differences in weight of either small, medium, large, or total potatoes at harvest were observed in this study for either site although there were occasional considerable numerical differences among treatments in some of the potato size classes.
Technical Abstract: Technical grade, liquid and granular formulations of Metarhizium anisopliae F52 were evaluated for wireworm control in small plots of potatoes at two sites in 2006. In-furrow treatments of three different formulations on day of planting: an emulsifiable concentrate (EC) diluted in water, a technical grade conidial powder (tgai) suspended in 0.1% Silwet L77, and a granular formulation were applied at a rate of 2 x 1013 conidia / acre. In a fourth treatment Metarhizium conidia was applied to seeds prior to planting at a rate of 2 x 1013 conidia / 2000 lb seed. The in-furrow treatments of EC and tgai were applied with a CO2 powered backpack sprayer. Cruiser® 5FS (0.16 oz / cwt) + TOPS MZ (12 oz / cwt) combination treatment was applied as a chemical standard; there was also an untreated check (TOPS MZ at 12 oz / cwt). Stand counts were similar among treatments. No statistically significant differences in weight of either small, medium, large, or total potatoes at harvest were observed in this study for either site, although there were occasional, considerably large numerical differences, e.g. in large potatoes in Site 2. There were no differences in percent wireworm-infested potatoes among treatments at either site. Significantly more potatoes per plant were harvested from the Metarhizium tgai + Silwet L-77 combination than from the untreated check in site #2.