Location: Plant Genetics ResearchTitle: Chromobacterium Csp_P biopesticide is toxic to larvae of three Diabrotica species including strains resistant to Bacillus thuringiensis
|HUYNH, MAN - University Of Missouri|
|PADDOCK, KYLE - University Of Missouri|
|CARAGATA, ERIC - Johns Hopkins University|
|DIMOPOULOS, GEORGE - Johns Hopkins University|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2022
Publication Date: 10/25/2022
Citation: Pereira, A.E., Huynh, M.P., Paddock, K.J., Ramirez, J.L., Caragata, E.P., Dimopoulos, G., Krishnan, H.B., Schneider, S.K., Shelby, K., Hibbard, B.E. 2022. Chromobacterium Csp_P biopesticide is toxic to larvae of three Diabrotica species including strains resistant to Bacillus thuringiensis. Scientific Reports. 12. Article 17858. https://doi.org/10.1038/s41598-022-22229-6.
Interpretive Summary: Corn rootworms are a major threat to corn growers in the Midwest. Rootworms have developed resistance to nearly all management strategies including corn hybrids expressing insecticidal proteins. In this research, we evaluated the survival of corn rootworm larvae to a biopesiticide made from a soil bacteria (Chromobacterium). All rootworm populations were susceptible including those that are resistant to genetically modified corn to a formulation of a biopesticide composed by air-dried soil bacteria on artificial diet. This biopesticide could become part of corn rootworm management strategy if also effective in a field setting.
Technical Abstract: The development of new biopesticides to control the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is urgent due to resistance evolution to various control methods. We have tested the air-dried non-live preparation of Chromobacterium species Panama (Csp_P), against multiple corn rootworm species, including Bt-resistant and -susceptible WCR strains, northern (NCR, D. barberi Smith & Lawrence), and southern corn rootworm (SCR, D. undecimpunctata howardi Barber), in diet toxicity assays. Our results documented that Csp_P was highly toxic to all three corn rootworms species based on lethal (LC50), effective (EC50), and molt inhibition concentration (MIC50). In general, toxicity of Csp_P was similar among all WCR strains and ~3-fold less toxic to NCR and SCR strains. Effective concentration (EC50) was also similar among WCR and SCR strains, and 5-7-fold higher in NCR strains. Molt inhibition (MIC50) was similar among all corn rootworm strains except NCR diapause strain that was 2.5-6-fold higher when compared to all other strains. There was no apparent cross-resistance between Csp_P and any of the currently available Bt proteins. Our results indicate that Csp_P formulation was effective at killing multiple corn rootworm strains including Bt-resistant WCR and could be developed as a potential new management tool for WCR control.