As we wait for soybean aphids to arrive, we discuss how the early and large outbreak of Japanese beetles in central Iowa may harm crop production. Dr. Hodgson discusses some options for preventing the beetles from clipping corn silk, a significant form of damage caused by these pests. For more info, visit Dr. Hodgson's blog at http://iowabuglife.blogspot.com
Today, Matt and Erin invite grad student, Mike Dunbar, to share his recent experience of true armyworm in a cornfield with a rye cover crop. Read more about true armyworms here: http://bit.ly/1QawkYf. Also, we have a brief discussion on slug management. Read more about slugs here: http://bit.ly/1HcZTUi.
Today, Matt and Erin talk about an old pest that is new again. European corn borer is making a comeback in some non Bt-corn. Identification and management are important for timely foliar insecticide applications. Also, Erin saw a small plot with increasing soybean aphid populations - it was also noted in other research plots compared to last week. Lastly, they talk about the potential usefulness of UAVs for making management decisions in field crops. The link Matt mentioned: http://n.pr/1GjpPBx/.
Today, Matt and Erin ask our 2015 Gunderson Memorial Lecture speaker, Dr. Dominic Reisig, a few questions about his research and extension program. Dominic is a field crop entomologist at North Carolina State University and has a wide range of responsibilities, for pest management including corn, soybean, cotton and wheat. Topics include stink bugs, kudzu bug, caterpillars (like Old World bollworm and corn earworm), and even soybean aphid.
Today, Matt breaks down a technical publication to Erin. This study evaluated the effect a lady beetle had on diamondback moth in Bt broccoli. Turns out, the presence of natural enemies can slow down the rate of Bt resistance. They talk about implications for this research in Iowa, specifically for corn rootworm in corn. Read the full article here: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0090366.
Today, Matt and Erin talk about the recent EPA proposal to revoke all tolerances to chlorpyrifos. This insecticide is an option in corn and soybean in Iowa and restricting or removing the use could have potential implications for field crop pest management. Matt shares a paper that shows a decrease of chlorpyrifos in corn but relatively steady use in soybean (doi:10.1088/1748-9326/10/9/094016). He isn't sure if revoking the use would have an immediate impact, but Erin offers a Coke analogy to say otherwise. To learn more about the EPA proposal and leave a comment, go here: http://www.gpo.gov/fdsys/pkg/FR-2015-11-06/pdf/2015-28083.pdf.
Matt and Erin have a special guest on this podcast to help understand life cycle assessments. Dr. Kurt Rosentrater is an engineer and associate professor at Iowa State. Kurt explained the basics of conducting a life cycle assessment, including assumptions and resulting complications that come with this tool. They focused on a recent example looking at environmental impacts in four major crops. Here is the link to the paper so you can follow along with figures: http://www.ingentaconnect.com/content/iop/erl/2015/00000010/00000009/art094016. The assessment showed freshwater ecotoxicity impact in soybean increased 3-fold from 2002 to 2012. The authors claimed the insecticides used to control soybean aphid was an important factor. Corn, cotton and wheat did not have a significant increase of impact over the study duration. Learn more about Kurt's research and teaching program here: http://www.abe.iastate.edu/kurt-a-rosentrater-assistant-professor/.
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.
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 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).