Update:
Spring planting conditions throughout Iowa were excellent and ahead of historical planting records. In general, drought conditions were evident and field in western Iowa, in particular, were stressed. Abnormally dry or moderate drought conditions persisted throughout the entire growing season. On August 10, a derecho moved through central Iowa and caused plant damage to commercial soybean.
Population fluctuations between locations and years is typical soybean aphid dynamics for Iowa. Soybean aphids arrived on soybean in July, which is average for Iowa. Soybean aphid colonization was initially patchy and continued to grow at a slow pace. Some commercial fields experienced exponential growth of soybean aphid after bloom, especially in northern Iowa. Several 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 (ISU Northwest Research Farm). I had 25+ treatments at this location where aphids exceeded the economic threshold. The complete 2020 summary will be available in December.
Soybean gall midge continues to emerge as an economic pest in Iowa. Five new counties were confirmed with infestations (total of 31 counties), and expanded to 114 total counties in five states (IA, MN, MO, NE, SD). I dedicated many extension programs to soybean gall midge and spoke about the limited information on biology, life cycle and management. Overall, severity of commercial fields was less than in 2019 and infestations tended to be more scattered within fields. I established efficacy evaluations at two locations in 2020. Multiple chemistries and sites of application were used, but emphasis was placed on suppressing overwintering adult establishment. Our 25+ treatments did not appear to delay or effectively suppress larval feeding.
In addition, there were a variety of caterpillar species present in soybean in 2020. Thistle caterpillar was not as abundant as in 2020 but the first generation in Iowa was higher than normal. Japanese beetle and bean leaf beetle populations were typical and spotty in commercial fields. Twospotted spider mites were obvious and sometimes an economic issue later in the season and is attributed to drought-stressed crops.
View uploaded report 
What does it mean for farmers: Effective management tactics are still limited for soybean gall midge, but our recommendations for best efforts to reduce the severity of plant injury are to:
• Plant soybeans last in areas (e.g., late May or early June) where heavy soybean gall midge pressure has been observed in previous years.
• Scout field edges first for initial detection of infested plants.
• Apply foliar insecticides at the time of adult emergence, typically around V3-V5 growth stages. Perimeter treatments may be a more cost-effective strategy at early vegetative growth.
• Additional insecticides may be required to suppress additional emergence.
What does it mean for farmers: Population fluctuations between locations and years is typical soybean aphid dynamics for Iowa. Our recommendation for soybean aphid management in Iowa is to:
• Strongly consider using host plant resistance if soybean aphid populations are persistent and the seed agronomic traits are appropriate for the area. The use of a pyramided gene will result in lower seasonal accumulation and reduce the need for foliar insecticides.
• Plant early if the field is in an area with persistent soybean aphid populations.
• Scout for soybean aphid, especially during R1–R5, and use a foliar insecticide if aphids exceed the economic threshold of 250 per plant.
• Use a product labeled for soybean aphid; most well-timed applications of foliar insecticides will provide yield protection if applied at the economic threshold and coverage is sufficient.
• Evaluate foliar insecticide efficacy three days after application to ensure soybean aphid populations were sufficiently reduced.
• Understand that late-season accumulation of aphids (i.e., after R5) may not impact yield like it does in early reproductive growth; a foliar insecticide applied after seed set may not be an economically profitable choice.