Internal and external barriers to herbivory: What's the best defense against the Soybean Aphid?

Monday, February 27, 2017 - 4:10pm
Event Type: 

Shelby Pritchard will be presenting her M.Sc. defense as part of the Department of Entomology's spring semester seminar series.

Abstract. Our objective was to determine if varying trichome density on soybean limits Aphis glycines Matsumura population growth in both lab and field settings. In the lab, we compared the impact of trichomes on A. glycines using 10 soybean isolines with varying levels of trichome density as well as an aphid-susceptible plant (i.e., positive control) and an aphid-resistant plant (i.e., negative control containing Rag1+Rag2). To determine the impact of trichomes on the biocontrol of A. glycines, we compared population growth on both caged and uncaged plants from these isolines within a field setting. We also looked at how effective three-gene pyramids would be against all A. glycines biotypes in a lab setting. For the trichome experiments we observed no significant impact of trichomes on A. glycines populations in both lab and field settings. However, we found that the three-gene pyramid (i.e., Rag1+Rag2+Rag3) was successful at suppressing all four A. glycines biotypes while the three-gene pyramid (i.e., Rag1+Rag2+Rag4) suppressed all A. glycines biotypes except for biotype-4.

The ENT seminar series is coordinated by Greg Courtney ( and Rick Hellmich ( Please feel free to contact them with questions.