The severe and prolonged extreme heat and rainfall shortages that have led to moderate and severe drought conditions across Ohio have also led to reports of the twospotted spider mite, a dangerous pest that can cause severe damage to soybeans, including the death of the entire plant.
Many growers have already reported finding twospotted spider mites on soybeans, says Ron Hammond, an Ohio State University Extension entomologist. Spider mites, which feed on the underside of the foliage with sucking mouth parts and can be destructive when abundant, thrive on plants that are under stress, especially in hot, dry field conditions, he said.
This is significant, considering that all of Ohio except for small portions of some counties near the West Virginia border is experiencing moderate drought, with areas near the Indiana and Michigan borders experiencing severe drought as of July 24, according to the most recent U.S. Drought Monitor.
"Numerous areas in the drier areas of Ohio are already seeing them, and some fields are already being sprayed," Hammond says. "Mites are showing up not only on field edges but also within the field.
"Twospotted spider mites have the potential to cause more yield loss than any other insect, with the damage caused by the mites being severe enough to kill the entire plant. Growers who have a bad infestation will not see any yield from the affected area."
Typically, Ohio growers are impacted by twospotted spider mites in July or early August, because moisture levels earlier in the year are usually high enough to keep the pests at bay, Hammond says.