WOOSTER, Ohio – Soybean growers are being encouraged to scout their fields amid scattered reports of high numbers of leaf defoliators making a meal of the crop.
Ron Hammond, an Ohio State University research entomologist with the Ohio Agricultural Research and Development Center, said that bean leaf beetles, Japanese beetles and grasshoppers are common across the state.
What to look for. “When scouting for soybean defoliators you want to focus on two things.
“First, you have to scout randomly across the entire field and not just confine your scouting to field edges.
“Japanese beetles and bean leaf beetles tend to feed across the field, while grasshoppers are normally found at field edges,” said Hammond.
Hammond also said to make sure not to confuse heavy top feeding with full plant infestation.
“Japanese beetles and bean leaf beetles tend to confine themselves to just the upper plant leaves.” he added.
When to treat. “Make sure that 15 percent defoliation is true for the entire plant before applying treatments,” Hammond said.
Soybean growers in western Ohio should also be keeping an eye out for the western corn rootworm variant that lays its eggs in soybean fields for hatching, and feeding, into corn fields the following year.
“Growers need to be out in their fields with yellow sticky traps,” said Hammond.
“We know the insect is in western Ohio. Right now we don’t think it’s a major problem, but it’s a big concern in other Midwest states, so growers need to at least be vigilant in their scouting for the variant.”
Aphids low. Despite the increased number of soybean insects this growing season, the biggest news for growers is what’s not present, and that’s the soybean aphid.
“We predicted we wouldn’t have the aphid in large numbers and right now it appears that our prediction is coming true.
“Very few fields have been reported to contain aphids and those fields that do have the sapsucker have few pests in number and are difficult to find,” said Hammond.
“We think that if we can go another two to three weeks without an increase in populations, we could be past the critical time, and we can say that our prediction was valid.”
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Get the details
Information on western corn rootworm can be found by logging on to ohioline.osu.edu/ent-fact/0017.html.
For more information on soybean insects, visit agcrops.osu.edu.