Evaluation of the effectiveness of entomopathogens for the management of wireworms (Coleoptera: Elateridae) on spring wheat

Abstract

Wireworms, the larval stage of click beetles (Coleoptera: Elateridae), are serious soil dwelling pests of small grains, corn, sugar beets, and potatoes. Limonius californicus and Hypnoidus bicolor are the predominant wireworm species infesting wheat in Montana, particularly in the 'Golden Triangle' area of north-central Montana. Wireworm populations in field crops are increasing, but currently available insecticides provide only partial control, and no alternative management tools exist. In our study, three entomopathogenic fungi were tested for their efficacy against wireworms in spring wheat at two field locations (Ledger and Conrad, Montana, USA) in 2013. The three fungi (Metarhizium brunneum F52, Beauveria bassiana GHA, and Metarhizium robertsii DWR 346) were evaluated as seed-coat, in-furrow granular, and soil band-over-row drench applications in addition to imidacloprid (Gaucho® 600) seed treatment (as a chemical check), the approach currently being used by growers. Wireworm damage in these treatments was evaluated as standing plant counts, wireworm population surveys, and yield. The three fungi, applied as formulated granules or soil drenches, and the imidacloprid seed treatment all resulted in significantly higher plant stand counts and yields at both locations than the fungus-coated seed treatments or the untreated control. Significant differences were detected among the application methods but not among the species of fungi within each application method. All three fungi, when applied as granules in furrow or as soil drenches, were more effective than when used as seed-coating treatments for wireworm control, and provided an efficacy comparable or superior to imidacloprid. The fungi used in this study provided significant plant and yield protection under moderate wireworm pressure, supporting their value in the management of this pest.

Effects of Seedling Age on Colonization Patterns of Citrus limon Plants by Endophytic Beauveria bassiana and Metarhizium anisopliae and Their Influence on Seedlings Growth

“…Similar observation was recorded in tomato plants treated with M. anisopliae, where treated plants showed significant improvement in height, shoot dry weight, root length, and root dry weight [51]. Improvement in the stand counts and yield of wheat plants treated with B. bassiana was also reported by Reddy et al [54]. The ability of endophytic fungi to induce the production of plant growth regulators is believed to be related to plant growth improvement.…”

Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana as potential biological control agents of Coelaemenodera elaeidis of the oil palm (Elaeis guineensis Jacq.)

“…The ability of M. anisopliae and B. bassiana to cause 100% mortalities with the emergence of fungi mycelia growths and sporulation of conidiophores from the cadavers of C. elaeidis clearly indicated that the entomopathogen strains were pathogenic. This agrees with Reddy et al (2014) and Schapovaloff et al (2014) on the susceptibility of Cerambycid beetle Hedypathes betulimus to B. bassiana and M. anisopliae. Maoye et al, (2014), reported that B. bassiana isolate had strong pathogenic and exhibited great potential for sustainable control of brown planthopper Nilaparavata lugeens.…”

Biology, Ecology, and Control of Elaterid Beetles in Agricultural Land

“…Fungal pathogenicity is affected by wireworm species (78), wireworm state, and environmental conditions: Mortality of A. obscurus larvae from Metarhizium infection increases with both temperature and biomass and depends on wireworm feeding state (77,161,163). The efficacy of entomopathogenic fungi in controlling wireworms (L. californicus, H. bicolor) also depended on the application method and can be superior to seed insecticidal treatments (117).…”