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The podcast took a break while Matt was on vacation and Erin was on the extension circuit. But they're back and talking about recent pest activity in Iowa. First, Erin shares updates about treating for soybean aphid in northern Iowa. Populations were erratic, as usual, and some fields exceeded threshold in early- to mid-August. A few people noticed poor performance of bifenthrin, a pyrethroid, for soybean aphid. This isn't a huge surprise, given there are pyrethroid-resistant populations in southwestern and southcentral Minnesota in 2015 and 2016. It is important to assess insecticide efficacy and determine potential issues with soybean aphid. In general, soybean are approaching mid- to full seed set throughout Iowa and yield responses are not consistent when applied after full seed set. 

In addition, Erin has noted some corn fields with abundant aphid populations. Some fields exceeded 1,000s per plant and were treated with aerial applications last week and this week. Economic thresholds for these pests are not well defined, but Erin has an ICM News article to take into consideration. 

Matt and Erin will be at the 2016 Farm Progress Show near Boone, Iowa on August 30. Erin will be at the ISU Event Tent in the morning and have a presentation at 10am. Matt will be there in the afternoon - so stop by and see them!

Today, Matt and Erin have so much to talk about in this episode. The multiple phone calls and people stopping by Erin's office can't stop the podcast. Lab members found a few soybean aphids in central and northeast Iowa. This is not too surprising because a few soybean aphids can usually be found in June. Populations are very low, but something to note as the field season continues.

The first soybean aphids of the year were found in northeastern Iowa. Photo by Greg VanNostrand. 

The warm winter was helpful to those insects trying to overwinter in Iowa, particularly for bean leaf beetle. For the other crop in Iowa, corn rootworm egg hatch is peaking, stalk borers are moving to corn, and European corn borer egg hatch is also happening now. Then the conversation turned to millipedes - not a typical field crop pest. They talk about field conditions conducive to millipede injury, in addition to other emerging pests like slugs, snails and isopods. Finally, Matt reminded us Pollinator Fest is coming up at Reiman Gardens in Ames on June 25. 

Random fact: Millipedes are arthropods within the class Diplopoda. They are distant relatives to insects and arachnids. People who study millipedes are called diplopodologists. 

Millipede. Photo by David Cappaert, www.ipmimages.org.