If a soybean aphids could talk, I would imagine them screaming, " Stop touching me!". Many Iowan fields are infested with soybean aphid this summer. Erin and Matt talk about what to do when these increasing populations happen late in the season. A short conversation about aphids in corn also happens. Finally, they get diverted and talk about winged aphid formation based on several cues, like touching and predators.
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!
In this mid-June episode, Matt and Erin start off by summarizing current soybean aphid activity around the state of Iowa. Populations are showing up over much of northern Iowa the last two weeks. Some fields have approached infestations ranging from 10-50%, although the density per plant remains low. Under ideal conditions, these populations could exceed the economic threshold in a few weeks. Brian Lang also found an aphid mummy, which is also early compared to most summers. Erin talked about a new publication for European corn borer that is available at the ISU Extension Bookstore. The 12-page pub reviews identification, life cycle, plant damage, scouting and treatment recommendations for this devastating pest. In their new segment, Matt talks semantics about how to spell one of the most widely recognized insects in the world.
It seems like a long time since the last episode and that's because it was! Matt and Erin are back to talk about pest updates in Iowa. Drought stress throughout much of the state has been ideal for twospotted spider mite. Erin reports Some injury has been observed in corn and soybean this summer. Treatments are going on now throughout some southern Iowa counties. In addition, soybean aphid continues to be an erratic pest. Some populations are building up in northern Iowa counties, but most fields are not reaching the economic threshold in July. Matt elaborates about high numbers of Japanese beetle and they talk about the use of pheromone traps as a management tool. Finally, Matt talks about a new Science research paper that has inconsistent data on the effect of neonicotinoid seed treatments on wild and managed bees in Europe.
Matt and Erin took a short podcasting break but are back to summarize late season soybean pest activity. Erin talks about a slight resurgence of soybean aphid populations in northern Iowa. Read more about treating at full seed set in a recent ICM Blog. Erin also recommends scouting in late August/early September for second-generation bean leaf beetles, as feeding injury to pods and seeds could be significant. Matt has noticed perhaps early field senescence in some commercial fields in Iowa. He also took a trip to Mississippi to see soybean production and learn more about pollinator protection. This podcast also features a F.I.T.!