Evaluation of reduced risk insecticides for management of wireworms (Coleoptera: Elateridae) on spring wheat

Soil dwelling larvae of click beetles (wireworms) remains a key pest of small grains, corn, sugar beets, and potatoes.  In north central Montana’s Golden Triangle area the predominant wireworm species infesting wheat are Limonius californicus (Mannerheim) and Hypnoidus bicolor (Eschscholtz).  The efficacy of reduced risk insecticides and mixtures in protecting wheat, Triticum aestivum L., from wireworm damage was assessed in the field.  Reduced risk insecticides (spinosad, Metarhizium brunneum F52, Beauveria bassiana, azadirachtin, and pyrethrin) were evaluated by either being applied alone, or in combination with other entomopathogenic fungi, and imidacloprid.  The seed treatment (imidacloprid) served as a standard.  Wireworm damage protection was measured at pre-treatment, 7, 14, 21, and 30 days post-treatment through plant stand counts.  Treatment effects on wireworm population were also measured by stocking bait traps placed in the plots at pre-treatment, 14, and 30 days post-treatment.  Seed yield and seed quality from feeding activities of wireworms were also assessed.  The data from the study is being compiled and will be discussed.