Update:
Spring planting conditions throughout Iowa were first cold and wet in 2019, and most soybean fields were planted later to accommodate corn planting. Then May was normal and June was wetter than normal in many locations throughout Iowa. Population fluctuations between locations and years is typical soybean aphid dynamics for Iowa. Soybean aphids arrived on soybean in July, slightly behind average infestation dates. Soybean aphid colonization was initially patchy and continued to grow at a slow pace, likely due to hot evenings providing little relief to adults. Some commercial fields experienced exponential growth of soybean aphid after bloom, especially in northern Iowa. However, few fields in northwestern and northcentral counties had soybean aphid exceed the economic threshold. Some populations did persist until after seed set (R5–R6), but very quickly crashed at most locations by mid-September. When applications had sufficient coverage and applied at the labeled rate, efficacy for soybean was good (i.e., >95% knockdown within three days after application) throughout most of Iowa. I was able to complete proposed work, including research and extension related to soybean aphid management. I established a foliar insecticide efficacy evaluation at one location in 2019 (northwest Iowa). I had 25+ treatments including soil-applied and foliar insecticide applications.
In addition to soybean aphid, Japanese beetle, bean leaf beetle, and soybean gall midge were prevalent in some Iowa soybean fields. I ended up spending a lot of time responding to questions and concerns about soybean gall midge. By the end of 2019, this new pest was confirmed along western Iowa in 26 counties (up from 18 in 2018):
I did not conduct any research on this pest, but did work with ISU Research Farm Managers, Iowa Soybean Association staff and farmers. This soybean pest is particularly devastating and can cause plant death. Affected plants were restricted to field edges and economic loss could be 100%. I dedicated many extension programs to soybean gall midge and spoke about the limited information on biology, life cycle and management. My program raised awareness of this new soybean pest and am arranging efficacy evaluations and a germplasm screening for 2019 at several locations.
My extension efforts for soybean IPM in 2019-2020 are summarized here:
Peer-Reviewed Extension Publications and Proceedings: 4
Hodgson, E. W., A. N. Dean, and Z. Wang. 2019. Using immediate feedback cards in extension.
Journal of Extension, in press April 2020.
Hodgson, E. W., and G. VanNostrand. 2020. Soybean aphid efficacy screening program, 2019.
Entomological Society of America Arthropod Management Tests. DOI: 10.1093/amt/tsaa053.
Lagos-Kutz, D., D. J. Voegtlin, D. Onstand, D. Hogg, D. Ragsdale, K. Tilmon, E. Hodgson, C. DiFonzo,
R. Groves, C. Krupke, J. LaForest, N. J. Seiter, E. Duerr, B. Bradford, and G. L. Hartman. 2020. The
soybean aphid suction trap network: sampling the aerobiologcal “soup.” American Entomologist.
DOI: 10.1093/ae/tmaa009.
Other Extension Publications:
3 proceedings
32 ICM News, Blog and Encyclopedia articles
Extension presentations:
Invited talks: 3
Other talks: 36
Field days: 12
Extension Videos: 4