Soybean Pest Podcast
Today, Matt and Erin cover a lot of topics. First, Erin summarizes her recent trip to Indianapolis for the 2017 North Central Branch ESA meeting. Lots of interesting papers and posters were presented this week. Also, the first confirmation of soybean aphid in Iowa happened again this week. It is typical to find aphids during early June in vegetative soybean, so listeners shouldn't be too concerned at this time. Other pest activity updates include more black cutworm and armyworm, plus a few bean leaf beetles and slugs. Matt follows up on the slug conversation by highlighting a recent interview with Penn State entomologist, John Tooker. As a follow up to the IRAC discussion a few episodes ago, Erin reminds everyone that the organization puts out a few helpful references on insecticide modes of action and resistance management.
Two events of interest coming up:
Pollinator Fest at Reiman Gardens is on June 24. It's free this year, so bring your family for some fun hands-on activities centered around pollinators.
Matt and Erin took May off from podcasting, but had a lot to talk about in the third episode of season 8. The cool, wet spring resulted in delayed planting for some; however, many of their research plots went in the ground this week. There have been a number of black cutworm and true armyworm reports throughout Iowa the last two weeks. Treatment decisions are based on plant growth stage, pest density and injury. Read more about their biology and management in ICM News articles:
Erin also reported common stalk borer is moving to corn and soybean, particularly in the southern counties. Fields with stalk borer injury should scout now. Also, some fields are experiencing slugs - injury is most noticeable in fields with high residue. Finally, Matt and Erin got a USDA Challenge Grant and are looking for an extension program specialist that can work with farmers, beekeepers and conservationists. Find the job description here.
Ashley Dean, new graduate student, helping plant her soybean research project at the NW Research Farm near Sutherland. Photo by Greg VanNostrand.
Black cutworm. Photo by Adam Sisson.
In Episode 2, Matt and Erin cover a range of topics. First, they summarize planting conditions for 2017 - most places in the state are too wet and and cold to plant. The weather also affects insect activity as well. Matt expands on a recent ICM News article by Erin regarding "green bridges." Both had students graduating this semester - congrats to Eric Clifton and Shelby Pritchard on all your hard work and efforts during your time at Iowa State! Finally, Matt updates us on the recent legislative activity to close the Leopold Center for Sustainable Agriculture.
It's a new beginning for the podcast - Season 8 starts today! Matt and Erin have a bit of random conversation at the beginning like usual. But they eventually provide a summary of the recent new of an organophosphate, chlorpyrifos. The EPA has been dealing with a petition to revoke tolerances for this widely-used insecticide. The EPA will not move forward with restricting chlorpyrifos in any crop; this could be important as farmers make product choices for 2017. Erin wrote a recent ICM Blog about it. Matt shared updates about his recent travels to the S1055 Soybean Entomology Working Group meeting in Memphis where he compares soybean production in the North Central Region to the South. Surprise - it's a lot different! Erin wraps up by providing overwintering mortality predictions for bean leaf beetle. The 2016-2017 winter was moderate and about half of the beetles are expected to survive. Read more in her recent ICM News article.
Bean leaf beetle adult. Photo by Winston Beck, ISU.
In the last episode of season 7, Matt and Erin talk about two new insecticide options for soybean aphid in Iowa. Movento and Sivanto by Bayer CropSciences are products that target fluid-feeding pests, like aphids, and are considered reduced-risk options compared to broad spectrum insecticides. Movento is a Group 23 and Sivanto is a Group 4D. To learn more about these insecticide groups, visit the IRAC website.
It's unusually warm this February episode. Like Bugs Bunny cartoon said - Gosh, it's hot! Matt and Erin talk about accumulating degree days for the state so far in 2017. Northern counties have accumulated between 16-22 degree days, while southern counties have accumulated 50-53 degree days. Erin uses the ISU Agronomy Mesonet to estimate temperatures. Matt also shared that the Toth Lab is noticed honey bee foraging already this year. There may not be much to feed on right now, which is concerning to beekeepers. Matt also shared some information on pyramided host plant resistance options for farmers in Iowa. Finally, Erin encouraged new agronomists to attend the Crop Scout School in Ames on March 25.
Matt's a bit under the weather in this episode, but that won't stop his awesome commentary (see connection to Michael Jordan here)! Today, Matt and Erin talk about a new research development with soybean aphid. The entire genome was recently sequenced; see journal paper here). This is only the fourth aphid genome to be sequenced so far. Colleagues, Drs. Brad Coates and Andy Michael, helped generate data for this journal article. Matt explains the reasoning for sequencing the genome of pest species like soybean aphid. Once we have a better understanding of the genetic makeup of a pest, we can try to disrupt it and make them less successful. Then, Erin shares some recent questions coming to her from around Iowa - particularly if snow cover can help insects survive the winter.
In this episode, Matt and Erin talk about managing twospotted spider mites in soybean. Considering other pests is important, given the non-target effects with an application. This is particularly true if soybean aphid is in the field because of recent reports of pyrethroid resistance. They discuss options, including using miticides to suppress mite populations. Implications of pest ecology and economics plays a part in managing soybean pests.
Twospotted spider mites. Photo by Frank Peairs; www.ipmimages.org.
It's the first podcasting episode of 2017! Matt and Erin talk briefly about a few topics related to insecticides today. First, Erin recaps the findings of her insecticide resistance project from 2016. A field sprayed twice with a pyrethroid (bifenthrin) did not have efficacy against soybean aphid. She conducted an assay and discovered elevated resistance ratios for bifenthrin and lambda-cyhalothrin. Distinguishing insecticide group will become important for future growing seasons so farmers can prolong the efficacy of pyrethroids and organophosphates. Learn more about insecticide groups and resistance management at the IRAC website. Matt shared updates on pending EPA approvals of existing insecticides. Chlorpyrifos, an organophosphate, had an open comment period that closed January 17, 2017; read more about the health risk assessment for chlorpyrifos. In addition, the EPA has four public comment dockets open now regarding pollinator-only risk assessments for the neonicotinoid insecticides clothianidin, thiamethoxam, and dinotefuran.
Erin and Matt are speaking at the ISU Crop Advantage Series this month. Find locations and registration details here. Erin is also speaking on a resistance management panel at the 2017 Iowa Soybean Research Conference on February 8, 2017.
Watch an IRAC video on how insecticide resistance happens!
Matt and Erin wrap up a few loose ends before the holiday week. First, Matt shares DowAgroSciences sulfoxaflor insecticide got a renewed registration. This insecticide targets fluid-feeding insects and was an option for soybean aphid before it was canceled in 2015. Now, sulfoxaflor can be used in a number of crops, but not for corn or soybean; cotton and sorghum have emergency labels in some U.S. states. Over the weekend, a soybean aphid Biotype-2 colony died due to a bad compressor in a growth chamber. Aphids don't tend to do well in temperatures over 100 degrees, and these ladies got cooked. Our labs host all four soybean aphid biotypes plus a few other aphid colonies. Colony management is really important and the maintenance is ongoing to keep plants and aphids healthy. Iowa State University features a 3MT (Three-minute thesis) oral competition this week. Three people featured insect-related presentations (a long video of all the speakers can be found here).
Upcoming extension events:
ICM Conference (30 Nov, 1 Dec) in Ames
Crop Advantage Series (January 2017) in Iowa
CCA Online Review Course, (on demand)