Soybean Pest Podcast
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!
This podcast episode focuses on a few recent pest updates, like soybean aphid, twospotted spider mites, and a mix of defoliators. Matt talks about spider mite activity in some of his research plots and also in fields near Brookings, SD. Erin notes soybean aphid activity is down throughout Iowa and they both revisit the economic threshold for this common pest. To read more information about why the economic threshold for soybean aphid remains consistently at 250 per plant, read this webpage co-authored by many university entomologists. Finally, Matt shares a research update on the release of parasitic wasps that like to feed on soybean aphid.
Don't drought this episode was a good one. Matt shares an update on the Iowa drought and encourages people to use the U.S. Drought Monitor as a tool to measure landscape moisture levels. Matt and Erin transition and talk about pest activity around the state, starting with twospotted spider mite. Erin wrote a recent ICM News article that talks about scouting and managing this pest that favors hot and dry conditions. Spider mites can be first detected around field perimeters and then eventually infest the field interior. Discoloration, webbing and stunted plants are often the result of heavy spider mite feeding. Erin mentioned a new miticide, AgriMek, that has promise for suppressing mites in corn and soybean; find the label here. The conversation switched gears to talk about some corn silk clipping pests, like Japanese beetle and corn rootworm adults. Scouting to determine pest densities and potential interference with pollination is important. Learn more about Japanese beetle ID, scouting and management with an ICM News article.
Twospotted spider mite. Photo by Frank Peairs, www.ipmimages.org.
Bean leaf beetle. Photo by Marlin Rice.
Today, Erin is so excited to tell everyone about her new, 12-page publication called, "Getting to Know the Insects." This publication is geared to youth and new agronomists that want to learn more about how to identify, sample and management field crop insects. It's available for $2 in the ISU Extension Store. Next, Matt and Erin talk about corn and soybean switching to reproductive stages around Iowa and implications for pest scouting and management. In particular, hot and dry weather favors twospotted spider mites, but expected cooler temperatures can promote soybean aphid populations. Erin also mentions a rare pest, redheaded flea beetle, showing up in a cornfield this summer. Read Erin's blog to see feeding injury on corn leaves. Erin also mentioned some upcoming field days at the ISU FEEL demo lab located between Boone and Ames, Iowa. The first is the Crop Management Clinic (13-14 July), which features a number of different topics related to crop production and protection. The second is an all-day workshop on corn insects (29 July). We aren't sure why, but there are a lot of references to MMA fighters in this episode??
Redheaded flea beetle on soybean. Photo by Lewis Veith.
Today, Matt and Erin talk about current pest activity in Iowa. Specifically, the last week was very hot (>90 degrees) and that isn't conducive for soybean aphid growth. So no new detection since the last podcast (but not surprised because aphids don't do well under consistently hot temps). Also, some alfalfa farmers are starting to see potato leafhopper injury. Matt heard about early twospotted spider mite injury in Illinois and that is a concern for extended hot and dry periods. Southeastern Iowa is abnormally dry right now and so be looking for initial spider mite infested along edge rows. Mite injury should not be confused with herbicide injury that is also starting to show up in some soybean fields. Finally, Erin and Matt talk about Pollinator Fest displays at Reiman Gardens. Erin will have the kids make Wikki Stik insects and Matt has prepared a honey tasting station.
Potato leafhopper (Photo by Marlin Rice) and classic "hopper burn" (Photo by Purdue Extension). To learn more about potato leafhopper, read this ICM News article.
Twospotted spider mite (Photo by Frank Peairs) and spider mite injury (Photo by Whitney Cranshaw). To learn more about scouting for twospotted spider mite, read this ICM News article.
Wikki Stik insect art for Pollinator Fest (Photo by Erin Hodgson).
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.
Today, Matt and Erin are in Cleveland, OH for the 2016 Annual North Central Branch Meeting of the ESA (Entomological Society of America). They have a conversation with special guest, David Gammel, Executive Director of ESA since 2011. They learn more about David's "origin story" and how he got connected with the ESA. He also shares some of the most exciting things happening with the organization, including new Policy Fellows, a fun blog, and the upcoming international meeting. The Policy Fellows program will support and develop scientists as visible and effective advocates for entomology and entomological research. The Entomology Today Blog helps translate insect-related news to a wide audience; recent articles include topics like a Zika symposium, emerald ash borer control, and tick-borne diseases. They also talk about our upcoming ICE (International Congress of Entomology) Meeting in Orlando this September. In addition to a lot of scientific content with over 6,000 expected participants, there will be informal chances to learn more about insects.
As the tagline for the new movie, Popstar, says: Never Stop Never Stopping!
Today, Erin gives a short note to announce the new podcasting widget. It will be located on their Soybean Entomology Lab website, where other resources are available. You can still subscribe to the podcast via iTunes, Stitcher or Pocket Casts. Thanks for listening!
In this episode, Matt and Erin talk about upcoming events, pest activity updates and research projects. Erin is organizing a Corn Insects Workshop on July 29. Learn more and register here: http://www.aep.iastate.edu/feel/insect.html. There is a 50-person cap, so register now if you want a space! Erin had several reports of pea aphid in alfalfa, but most farmers decided to cut instead of spray. Learn how to identify aphids in alfalfa here: http://crops.extension.iastate.edu/cropnews/2016/05/aphids-showing-alfalfa. Erin also saw a few aphid mummies in clover and they both experienced honeydew dripping from a tree on campus this week. Matt talked a bit about planting conditions for his wasp and bee projects, noting compaction and crusting in some commercial soybean fields.
Bad weather and superstition won't keep Matt and Erin from podcasting today. Erin shares current planting progress for Iowa (80% corn and 30% soybean) according to NASS and also talks about black cutworm injury in seedlings. Early-season clinics are starting up next week at FEEL, where she will help new agronomists learn about scouting for seedling pests. Finally, they talk about potentially podcasting on the road for the north central branch meeting in Cleveland next month.