Colorado Wheat Entomology Newsletter – June 28, 2021

Darren Cockrell:


Dr. Punya Nachappa:


Season Wrap Up

With the wheat drying down across the state and harvest beginning, this will be the last Wheat Entomology Newsletter for 2021. We would like to thank the countless researchers, extension agents, and cooperators across the state that contributed to and made this report possible, as well as Dr. Frank Peairs for continuing to provide insight on pest problems during his retirement Overall, we had a very successful year of research involving pests of wheat across the state, and hope that the research from this year will help support Colorado farmers. It was a pleasure to meet so many of you at the Wheat Field Days, and we look forward to another successful year of wheat entomology research.

Wheat Stem Sawfly – Adult Flight

The adult wheat stem sawfly flight has ended in Northern CO. The flight lasted approximately 5 weeks and peaked with an average of 297 adults found across the seven collections sites near New Raymer and Orchard, CO (Figure 1). Lodging caused by sawfly larvae feeding is likely already present in infested fields or will be soon.

Wheat Stem Sawfly – Stubble Survey

The annual wheat stem sawfly survey will begin after wheat harvest this year to determine the scope of sawfly infestations throughout the state. Newly harvested wheat stubble will be collected from sites across Eastern CO and dissected to look for sawfly larvae. A comparison of the 2013 and 2020 surveys is shown in Figure 2. Results from the 2021 survey will be available in the fall.

Other On-going and Recently Completed Wheat Stem Sawfly-Related Experiments in 2021

  • Understanding the Impact of Solid-, Semi-solid and Hollow Wheat Varieties on Natural Enemies (funded by CWRF; Figure 3).
  • Screening ancestral wheat species for novel sources of resistance to sawflies (funded by KSU Wheat Genetics Resource Center; Figure 4).
  • Determining triticale’s effectiveness as a trap crop to wheat stem sawfly (funded by CWAC; Figure 5).
  • Screening of current CSU Elite wheat breeding lines for solid stem traits (funded by CWAC).
  • Determining the efficacy of the systemic insecticide Endigo as an effective control measure for wheat stem sawfly infestations (funded by Syngenta).
  • Monitoring wheat fields post-harvest for parasitoids of the wheat stem sawfly ((funded by CWAC; Figure 6).


Wheat Diseases

For wheat disease updates by Dr. Robyn Roberts, please see:


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