For the past 5 years, we have evaluated insecticides for managing soybean aphids. The most recent report can be found at our website www.soybeanaphid.info. After applying insecticides as part of our 2009 insecticide evaluation, Erin and I discuss some issues to consider when selecting an insecticide
Dr. Hodgson and O'Neal talk about the preharvest intervals for those soybean growers considering an insecticide late in the season.
We discuss the likelihood that aphid outbreaks will occur and when to spray aphid populations. Some agri-businesses are suggesting that aphids be sprayed when populations are lower than 250 aphids per plant. We discuss the value of such lower thresholds, as well as ways to detect other invasive insect pests of soybeans.
Soybean aphid populations reach threshold in Iowa and japanese beetles are becoming an increasing problem for both soybean and corn. In this episode we discuss both of these pests and the need to scout now to determine the need for an insecticide. To learn more about Japanese beetles see Dr. Hodgson's latest article in the Integrated Crop Management newsletter (http://www.extension.iastate.edu/CropNews/2011/0722hodgson.htm).
Aphid populations continue to increase in Iowa. We discuss their trajectory and when/if insecticides will be needed. Also, new publications from Iowa State University are available for the soybean aphid and the brown marmorated stink bug. To purchase the id guide for stink bugs or the new soybean aphid field guide visit the ISU extension publication store (www.extension.iastate.edu/store). To learn where the brown marmorated stink bug is in Iowa visit www.ncipmpipe.org.
The growing season is coming to an end and aphids still persist in some areas. We discuss how insecticides may cause problems with spider mites, especially with the use of pyrethroid-based insecticides. Also look for updates regarding bean leaf beetle threshold calculator in the ICM newsletter next week. Thanks to Mike McCarville.
As soybeans reach the late reproductive stages the need to manage aphids decreases. However, aphids persist in soybean fields around the midwest. We discuss a couple factors that should be considered when applying insecticides this late in the year. Also, we re-count the spread of Japanese beetles in Iowa as a new herbivore of soybeans.
June is often a quiet month for insect pests but not this year as the Japanese beetle has emerged 2 to 3 weeks earlier then usual. So even though soybean aphids are uncommon right now, farmers may want to scout for this pest. We discuss what to look for and what the impact could be. To meet with Dr. Hodgson, consider joining her at the Crop Management Clinic (11-12 July) at FEEL. Visit this site for more information http://www.aep.iastate.edu/feel/cmc.html
It's hot! But we can still talk about aphids and other insect pests. It is a quiet week for soybean pests, but things are getting active in corn. We talk about what to look for when it comes to silk feeders. For more details about rootworms, a silk feeder and rootfeeder, look up Erin's recent factsheet. https://www.ent.iastate.edu/dept/faculty/hodgson/files/ul/CRW%20management%202012%20final.pdf.
At the end, Matt talks about a recent blog that summarizes his work on bees in soybean fields, http://www.agriculture.com/farm-management/conservation/bees-in-bes-qa-with-matt-oneal_556-ar32490.
Erin and Matt discuss the recent cool temperatures forecasted for the last week of July and the implications for soybean aphid populations in Iowa. We also discuss the recent emergence of bean leaf beetles and observations about the Brown Marmorated Stink Bug. For more info about the BMSB, visit http://apps.csi.iastate.edu/pipe/?c=entry&a=view&id=20