Erin Hodgson
Dr. Erin Hodgson started working in the Department of Entomology at Iowa State University in 2009. She is an associate professor with extension and research responsibilities in corn and soybeans. She has a general background in integrated pest management (IPM) for field crops. Dr. Hodgson's current extension and research programs are focused on improving corn and soybean production by using IPM tactics to protect yield and increase overall farmer profits. Among other projects, she oversees insecticide efficacy evaluations for soybean aphids, Japanese beetles, and aphids in corn. Erin also helps manage emerging field crop pests and invasive species.
Subscribe to RSS FeedISU Field Agronomists around the state have noted Japanese beetle feeding injury in corn and soybean over the last week. Japanese beetles have a wide host range that includes many species of fruit and vegetable crops, ornamentals, and field crops. Adults prefer to feed between soybean leaf veins...
The lowest level of insect injury where damage can be measured is called the damage boundary. The damage boundary is a biological relationship between the insect, crop, and environment; and is independent of input costs (e.g., seed, insecticide, etc.). Managing a pest below the...
Soybean aphid feeds fluids within the phloem fluids (sometimes referred to as "sap") by inserting piercing-sucking mouthparts directly into the phloem vessels. Prior to feeding, aphids "taste" the sap to determine if the plant is a suitable host species and if the quality is acceptable. Once...
Western corn rootworm (WCR) and northern corn rootworm (NCR) eggs overwinter in the soil and larval hatch is based on accumulated degree days (ADD) of soil temperatures each year. Average hatching dates for Iowa are in early June, with southern counties experiencing egg hatch before northern...
Last week, my lab crew found a few different caterpillars feeding in our soybean plots at the ISU Northwest Research Farm. They were hesitant to identify it in the field, so they brought one to me for a confirmation. First, I noticed it had a green body and green head and four pairs of prolegs...
This week, I got a note from Tristan Mueller (Iowa Soybean Association) seeing some corn leaf injury from redheaded flea beetle. The defoliation was noticeable and the farmer was considering a foliar insecticide. The fields did not have tasseled yet and he estimated 5-6 beetles per plant.
Earlier this month, I wrote an ICM News article showing peak corn rootworm egg hatch in Iowa. That means at least 50% of viable eggs have likely hatched and larvae will start feeding...
I recently had a call about millipedes feeding on corn kernels in northeast Iowa this week. The farmer had a 120-acre cornfield with approximately 20 percent stand loss associated with millipede feeding. I rarely hear about millipedes as field crop pests, but a couple factors likely played a...
Yesterday, my lab crew went to the ISU Northeast Research Farm near Nashua, Iowa to assess plant stands and take initial aphid counts in my efficacy evaluation trial. My technician found five wingless soybean aphids in a V1 plant. This was certainly interesting, as it could mean uniform colony...
Today, I heard about some armyworm feeding on corn in northeast and northwest Iowa. In the NE Iowa field, rye was planted last fall and killed late this spring. Armyworms tend to be aggregated, or found in big groups, and can cause significant injury seemingly overnight. The caterpillars are...
Although most of my research projects are outside, I occasionally do work in growth chambers and greenhouses. This week, I started a seed treatment evaluation for soybean. I'm looking at 12 different treatments and seeing how soybean aphid responds. Working in more stabilized conditions takes...
Yesterday, I was asked to help confirm an identification of a few beetles in a cornfield near State Center, Iowa. They ended up being striped and spotted cucumber beetles. Sometimes the striped cucumber beetle can be confused with western corn rootworm; however, it would be unlikely to see adult...
As Merle Haggard said in his song, Under the Bridge, “you’ll find some great grub feedin’ here below.” I got a couple calls about grub injury in seedling corn last week and how to identify annual grubs (e.g., masked chafers and Japanese beetle) from true white grubs (May and June beetles) with a...
In March, I posted a blog about alfalfa weevils laying eggs in SE Iowa. Degree days have been slowly accumulating in April. I've updated the degree day map for 2016 and alfalfa weevils should be...
Bean leaf beetle adults are susceptible to cold weather and most will die when the air temperature falls below 14°F (-10°C). However, they have adapted to winter by protecting themselves under plant debris and loose soil. An overwintering survival model developed at ISU in 2000 is helpful for...
You may have heard of brown marmorated stink bug (BMSB), an invasive insect making its way across the U.S. The first live detections of BMSB in Iowa were in 2011. Laura Jesse, Director of the Plant and Insect Diagnostic Lab, has now confirmed BMSB in 12 Iowa counties (see a map...
Adult alfalfa weevils begin moving as soon as temperatures exceed 48°F and begin laying eggs in alfalfa. Alfalfa weevil eggs develop based on temperature, or accumulating degree days, and hatching can start around 200-300 degree days. Start scouting alfalfa fields south of Interstate 80 at 200...
I was curious to compare growing degree days (GDDs) over the last couple summers. It seemed like 2014 and 2015 were cool, wet springs with a slow start for insects. But I wanted to check actual temperature history instead of relying on my memory. I used the ISU Agronomy...
While going through the extension winter gauntlet, I talked a lot about corn rootworm. It is one of most important pests in the Midwest and should be on your mind when deciding on hybrids and insecticides. I often got questions about using stacked and pyramided corn hybrids, and there seemed to...
Generally speaking, warmer winters mean more insects are likely survive because they aren’t exposed to lower lethal temperatures. An early spring can also benefit insects, particularly those species we consider field crop pests, because they are physically larger when crops emerge and can cause...
It’s not easy for insects to survive Iowa winters. Some literally can’t - they freeze to death or migrate away to warmer climates. But many insects have adapted to cold temperatures by entering diapause, which is like hibernation. Diapause is a developmental arrest to survive adverse seasons...
Many of you know about naturally-occurring entomopathogens in the soil that can kill or suppress insects. Bacillus thuringiensis (Bt) is a well-known example of a bacteria that kills insects, and was eventually included in plants as a transgenic protein. My Ph.D. student, Eric...
As harvest begins and other plants in the landscape senesce, many insects and arthropods move to find overwintering habitat. Sometimes...
The last few weeks have been full of soybean aphid discussions. Populations have been going up, down and otherwise looked sort of bumpy this summer. Many fields exceeded the economic threshold of 250 per plant and were treated with foliar insecticides in August, particularly in northern Iowa. My...
Corn rootworm adult emergence is underway in Iowa. The three species of rootworm found in Iowa include the northern corn rootworm (NCR), southern corn rootworm (SCR), and western corn rootworm (WCR). Adults of all three species can be found until the first frost. Knowing how to distinguish the...