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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Soil Management and Sugarbeet Research » Research » Publications at this Location » Publication #423995
Research Project: Agricultural Management for Long-Term Sustainability and Soil Health

Location: Soil Management and Sugarbeet Research

Title: ‘Beneficial Bug Baler’: A novel technique for mass relocation of Bracon in support of Cephus cinctus biocontrol in wheat, Triticum aestivum, 2024

Author
item BRADSHAW, JEFF - University Of Nebraska
item Rand, Tatyana
item Peirce, Erika
item NACHAPPA, PUNYA - Colorado State University
item OSTERHOLZER, ADAM - Colorado State University
item EASTERLY, AMANDA - University Of Nebraska
item CREECH, CODY - University Of Nebraska
item STRUCKMEYER, BILL - University Of Nebraska
item Poss, David
item SCHMALE, DOUG - Farmer
item LINNEBUR, ALAN - Farmer
item Mankin, Kyle
item Miner, Grace
item Hardy, Cody
item Floyd, Bradley
item Kleinman, Peter

Submitted to: Arthropod Management Tests
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2025
Publication Date: 4/25/2025
Citation: Bradshaw, J.D., Rand, T.A., Peirce, E.S., Nachappa, P., Osterholzer, A., Easterly, A.C., Creech, C.F., Struckmeyer, B., Poss, D.J., Schmale, D., Linnebur, A., Mankin, K.R., Miner, G.S., Hardy, C.D., Floyd, B.A., Kleinman, P.J. 2025. ‘Beneficial Bug Baler’: A novel technique for mass relocation of Bracon in support of Cephus cinctus biocontrol in wheat, Triticum aestivum, 2024. Arthropod Management Tests. 50(1). https://doi.org/10.1093/amt/tsaf072.
DOI: https://doi.org/10.1093/amt/tsaf072

Interpretive Summary: The wheat stem sawfly is an insect that causes $350 million in damage to wheat crops. Scientists from USDA-ARS, universities, and industry in the Western Great Plains worked together to test a simple idea: using hay bales to move lots of the sawfly’s natural predators to new places. This easy method could help farmers manage sawflies as part of a bigger pest management plan.

Technical Abstract: Wheat stem sawfly (Cephus cinctus) has been a key wheat pest for over 100 years. Biological control of C. cinctus is predicted to be effective when populations of two parasitoids Bracon cephi and Bracon lissogaster, parasitize at least 68% of the wheat stem sawfly population within a field in Montana and Nebraska. State-wide C. cinctus surveys have found no evidence of parasitism in winter wheat in Colorado. We aimed to provide evidence that Bracon from Nebraska can be transported to Colorado and successfully establish in wheat fields. We found that 32-35 Bracon adults emerged per kg of straw after baling. 78–85 Bracon adults emerged per kg of loose straw, suggesting our baling methods could be improved. Pre-harvest sampling found that 13-31 percent of C. cinctus infested stems were successfully parasitized by Bracon. This suggests that harvesting may have removed Bracon that were pupating at higher points in the stem. We also sampled at field edges and 50m within the field and found that Bracon were moving into the fields to parasitize C. cintus. This experiment indicates that swathing, baling, transporting, and then spreading wheat straw (sourced from a post-harvest field) is a viable methodology for the introduction of Bracon into new habitats, for the purpose of the biological control of C. cinctus in wheat production.