Poster Display
Plant-Insect Ecosystems
Jeffrey D. Bradshaw
Professor and Director of the Doctor of Plant Health Program
University of Nebraska
Lincoln, Nebraska
Vinicius Andrade
University of Nebraska
Lincoln, Nebraska
Cody Creech
University of Nebraska
Scottsbluff, Nebraska
Amanda Easterly
University of Nebraska
Sidney, Nebraska
Katherine Frels
University of Nebraska
Lincoln, Nebraska
Pin-Chu Lai (she/her/hers)
Assistant Professor and Extension Specialist
University of Nebraska
Scottsbluff, Nebraska
The wheat stem sawfly (WSS), Cephus cinctus, is a key pest of wheat on the High Plains. As a larva, this pest reduces wheat yield through its stem-boring activities that interrupt plant vascular systems and cause tiller lodging as it forms a pupal chamber. Lodging can be mitigated both by host plant resistance (HPR) and by Bracon spp (a WSS parasitoid) and potentially protect grain mass. However, the effect of WSS on grain mass nor any potential mitigation provided by current HPR or WSS parasitism is not well understood. Therefore, we examined twelve hard red winter wheat varieties according to their trait attributes including HPR and susceptible varieties under a randomized complete block design with four replications for three years. Each plot was comprised of paired subplots -- one with a insect exclusion cage (placed during the WSS flight period) and one open. At harvest, kernel mass per wheat tiller was evaluated. Stem samples were split to assess WSS larval presence, morbidity, WSS parasitism, and injury. For all years all varieties experienced > 60% infestation rates from WSS and contributed to 21-28% grain mass loss per tiller across all varieties. Conservatively, we estimated approximately 5-17 mg/tiller in grain mass loss per cm of WSS injury.