Erin Hodgson
Iowa State University’s IPM Team has monitored field crop pests for a long time. The pests have changed over the years, but the goal is the same: to help inform farmers about pest activity in Iowa. Our moth trapping efforts target migratory moths. Black cutworm monitoring is a long-standing...
Soybean gall midge is an emerging pest that only occurs in five Midwest states. Researchers in Nebraska, Iowa, Minnesota, and South Dakota began investigating this pest in 2019 after widespread reports of significant injury raised awareness early in the 2018 growing season. Although a lot of...
We are looking to hire a new Extension Field Agronomist to serve south central Iowa (Clarke, Lucas, Monroe, Wapello, Jefferson, Decatur, Wayne, Appanoose, Davis, and Van Buren counties). Field agronomists provide educational leadership and subject-matter expertise in crop production and...
The range of soybean gall midge has expanded in 2020. There are three new counties in Iowa (Osceola, Dickinson, and Calhoun) for a total of 29. So far, 108 total counties are confirmed in Iowa, Minnesota, Missouri, Nebraska, and South Dakota. Likely more counties have soybean gall midge but...
Caterpillars have been extremely active this year, especially in soybean. We suspect that late-season infestations of caterpillars in corn are no exception. These infestations are serious because these caterpillars feed on the ear and/or tunnel into stalks. Their feeding can also lead to...
With several severe weather events in Iowa this month, reports of lodged corn are coming our way. Often times, a small part of the field is flattened and would be difficult to see from the edge. I encourage you to get out into cornfields and see how your stands look this month. In some cases,...
I was recently asked about an alien-looking caterpillar from central Nebraska. I occasionally see silver-spotted caterpillars in Iowa and wondered if you were seeing any in soybean?
The caterpillars are definitely a unique species because of the body coloration! The bodies are yellow-...
After visiting several ISU Research and Demonstration Farms this week, our summer crew started seeing caterpillars in soybean plots. Many species are possible at once, but rarely do they cause economic injury in Iowa. Defoliation must exceed 20% after bloom to justify a rescue foliar treatment...
Today, with Ashley Dean and Angie Rieck-Hinz, I met Warren Pierson at FEEL to look for corn rootworm larvae. I predicted peak corn rootworm egg hatch for central Iowa this week based on accumulating degree days. We had no trouble finding larvae in refuge corn, ranging from ¼ to ½ inches in...
Today, ISU entomology graduate student, Mitchell Helton, captured the first adult soybean gall midge in Iowa. Just a few hours later, cooperator Lauren Botine (Corteva Agriscience), collected another adult. Currently, our traps are placed in fields infested with soybean gall midge in 2019. There...
Thanks to ISUEO Field Agronomist Meaghan Anderson and Extension Entomologist Ashley Dean, I had a great field scouting adventure in central Iowa. First visiting the field for poor germination and other issues, Meaghan was digging in the soil in search of more information and found grubs! So of...
Western and northern corn rootworms are serious corn pests in Iowa and the Corn Belt, reportedly responsible for over 1 billion dollars in yield loss and control costs annually in the United States. The larvae tunnel into and consume corn roots, which can reduce nutrient and water uptake (Figure...
Iowa’s most significant soybean insect pest, soybean aphid, has host-alternating biology. This species has multiple, overlapping generations on soybean in the summer. Fall migration to buckthorn is based on senescing soybean, and decreasing temperatures and photoperiod. For the majority of the...
Thin Lizzy predicted it in 1976. Actually, the boys and girls are back in town. Over the weekend, the first painted lady butterflies were spotted in Iowa. Why care about this beautiful butterfly? It seems like a distant memory, but remember the thistle caterpillar bonanza on soybean last summer...
Iowa State University’s IPM Team has monitored field crop pests for a long time. The pests have changed over the years, but our goal is the same: to help inform farmers about pest activity in Iowa. Our moth trapping efforts target migratory moths. Black cutworm monitoring is a long-standing...
This week was my last field day of the summer – it’s always is a signal the season is ending. I noted plants are senescing fairly quickly on my drive to Kanawha. However, there are still a few insects active on field crops, and worth scouting for this weekend.
Yesterday, while waiting for my field day stop to begin at the ISU Northeast Research Farm, I noticed a bright green insect land on my leg. At first glance, I thought it was the threecornered alfalfa hopper (Photos 1 and 2). I’ve never seen one in real life and was surprised to see it in...
Today in our corn efficacy evaluation trial, Ashley and our undergraduate team found small corn earworm caterpillars infesting ears (Figures 1 and 2). Caterpillars have a light-colored head but vary considerably in color from light green, tan, pink, maroon, and nearly black. However, they almost...
I was recently asked if adult corn rootworms are done emerging for 2019. Of course, I respond by saying – it depends! A publication by Nowatzki et al. (2002), developed an emergence model for northern and western corn rootworm in...
Today for the first time this summer, I started to notice a few thistle caterpillars that didn’t look quite right. Some were very dark, some look deflated and some were kind of “slimy” in appearance. This happens to insects occasionally as a result of infection of an entomopathogen. That’s just...
My lab has been collecting adult and larval soybean gall midge for a few weeks. We used emergence cages in several habitats to collect adults. This year, they were only collected from 2018 soybean fields in Iowa. Two of my trapping locations have identified second-generation adult captures this...
After visiting several ISU Research and Demonstration Farms this week, it was evident the abundance and diversity of caterpillars in soybean is ongoing. These species represented several insect families. We easily found 8 species while looking at and sweeping early-reproductive soybean. Of...
I was a speaker at the ISU Northern Research Farm field day near Kanawha yesterday. So many questions about thistle caterpillar and soybean gall midge. I also saw some feeding injury to vegetative corn. Here are some pictures:
This year I’ve had a few people ask for tips on scouting for common stalk borer. The larvae are moving from brome to corn throughout Iowa and it is a good time to scout for timely management....
The most effective way to make treatments decisions for pests with chewing mouthparts (e.g., Japanese beetle, bean leaf beetle, caterpillars, and grasshoppers) is to estimate defoliation. I’m a “lumper” and don’t try too hard to distinguish feeding by species. Replicated data over multiple...