Scouting for stalk borer infestations

by | Jun 19, 2019 | 5 Ag Stories, News

Agricultural officials report 98-percent of Iowa?s expected corn crop has been planted.

With planting close to complete, the focus now turns to pest and weed pressure.

An entomologist outlines what pests farmers should be scouting for.

Common stalk borer infestations are up this year, according to reports from Iowa farmers.

Erin Hodgson, Iowa State University Extension entomologist, encourages growers to scout for this pest.

“They overwinter in bromegrass – they’re stem feeders, so they’re inside the stem – but that gets too small after they get to a certain size. They’ll move to crops like corn and sometimes, soybeans.

Timing of termination is key, says Hodgson.

“When they’re moving from brome to field crops is the time to make a treatment. Once they get into their new house, an application won’t be as effective,” Hodgson said. “Get out there (and) look at field parameters to see if you have infestations in the brome and see if they’ve started that movement over to the field crop.”

Application recommendations are for peak larval movement, or 1,400-1,700 degree days.

“It’s not hard to kill a common stalk borer, if you can make contact. A pyrethroid is going to be an effective option,” Hodgson said. “What I would recommend – because they are a perimeter pest – is spot treatments along the field edge that seems to be infested. That will save time, money and product.”

Common stalk borer will cause plant death, if left untreated.

“As the name suggests, they’ll bore into a corn or soybean plant and feed from the inside. And because of this, they’ll kill the growing point and cause plant death. In some cases, you’ll have significant stand loss along field edges, from common stalk borer,” Hodgson said.

Hodgson also encourages producers to keep an eye out for caterpillars.

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