As soybean begin to produce pods and seeds, it becomes a good food source for stink bugs. These insects like to feed on the developing seed, leading to wrinkled or shriveled seed. There are many types of stink bugs, but Ohio’s most common stink bugs include the green, the brown, and the brown marmorated. Also, stink bugs have nymphal stages that can look very different than the adults—nymphs are smaller and lack wings but feed all the same, if not more, than the adults. To look for stinkbugs, take a set of 10 sweeps in 10 different areas of the field (although stink bugs are mostly found along the edges, they can also be found in the interior of the field). If the average number of stink bugs is higher than 4 per set of 10 sweeps, treatment is necessary (this decreases to 2 per set of 10 sweeps if soybean is grown for seed or food grade). Visit our website for more information on stink bugs in soybean, including helpful guides for identification (aginsects.osu.edu).
Western bean cutworm (WBC) trap counts for the week of August 10 – 16 decreased over the past week putting all monitoring counties below the scouting threshold. The low numbers indicate we are officially past peak flights. Overall, a total of 27 counties monitored 90 traps, resulting in 38 WBC adults (a statewide average of 0.4 moths per trap) (Figure 1).
Figure 1. Average Western bean cutworm adult per trap followed by the total number of traps in the county in parentheses for the week ending August 16, 2020.
My colleague Erika Lyon wrote a great article on the January 24th, 2019 All About Grazing column in Farm and Dairy (link) that discussed the invasive Asian long-horned Tick. I want to give an update on where that tick is now, where its new host range is located, and what potential disease problems to look out for.
The Asian long-horned tick is native to East Asia as well as Australia and New Zealand. It had not previously been found in the United States prior to its discovery on a farm in New Jersey in the fall of 2017. This tick is a major concern as it reproduces via parthenogenesis, which means that the female does not need a male in order to reproduce, she can start laying eggs, which are genetic clones, that can overwhelm the host in very large numbers. It has been found on humans, companion animals including cats, dogs and horses, livestock species including chickens, cattle, sheep and goats and multiple other mammals and birds including foxes, bears, geese, deer, raccoons, skunks, hawks, groundhogs and opossum (which are known to consume ticks as food). Continue reading
Western bean cutworm (WBC) trap counts for the week of August 3 – August 9 continue to decrease in the majority of monitoring counties. Trap counts indicated only one county, Lake, had an average of 7 or more moths, suggesting scouting is necessary. Overall, a total of 26 counties monitored 89 traps, resulting in 111 WBC adults (a statewide average of 1.2 moths per trap) (Figure 1). Monitoring for WBC moths will continue in many counties until the end of August.
By Kelley Tilmon, Andy Michel
As the summer progresses we are receiving reports of insect problems often encouraged by hot, dry weather. Last week we reported on spider mites and especially if you are in an area of continued dry weather we recommend scouting your soybeans and corn https://agcrops.osu.edu/newsletter/corn-newsletter/2020-22/watch-spider-mites-dry-areas .
Some areas are also reporting increases in young grasshoppers in soybeans, another insect favored by dry weather. Grasshoppers of often start on field edges so early scouting may allow for edge treatment. Japanese beetles are another common defoliator of soybean that are starting to appear. Both of these pests fall into a general defoliation measurement, and we recommend treatment if defoliation is approaching 20% on the majority of plants in post-flowering beans. Download our guide to estimating defoliation in soybean at https://aginsects.osu.edu/sites/aginsects/files/imce/Leaf%20Defoliators%20PDF_0.pdf Continue reading
By: Andy Michel, Curtis Young, CCA, Kelley Tilmon
We received many reports of true armyworm infestations in wheat, barley, and corn. These are black or green caterpillars with stripes along the side and orange heads. In the spring, true armyworm moths migrate from the south and lay eggs in grasses such as forage and weed grasses, winter wheat and barley, and rye cover crops. When the eggs hatch, the larvae can significantly damage wheat and barley before then moving to young corn. Usually, moth flights occur in April, but we may have had a second peak the first or second week of May—it’s likely the caterpillars feeding now are from this later flight. Right now, wheat, barley, and corn should be inspected for true armyworm populations. Armyworms like to hide during the day and feed at night, so scouting should occur at dusk or dawn, and/or on cloudy days. Continue reading