Weather, late planting make pest scouting crucial

Weather, late planting make pest scouting crucial

WITH fields in Ohio beginning to dry out from the excessive rains experienced throughout the state and as temperatures begin to rise, crop growers should scout their fields for insects that have the potential to cause economic losses, Andy Michel, an Ohio State University Extension pest expert, said.

In addition to cereal leaf beetle, alfalfa weevil and black cutworm, crop growers need to be on the lookout for slugs, especially in fields with a history of slug damage, said Michel, an entomologist with Ohio State's College of Food, Agricultural & Environmental Sciences.

The region is likely entering a period of heavy slug feeding, so corn and soybean growers need to be out inspecting their crops for the pests, he said. The slug issue was exacerbated by the cooler, wet weather experienced throughout the region this spring, which has caused delayed planting.

"Slugs could be worrisome this year because we've had a lot of moisture, and they are at their heavy feeding stage," Michel said. "We've got a lot of crops that are just getting in the ground or just emerging, which is when they are most susceptible.

"Delayed planting is impacting the ability of the plants to withstand some of the pest damage," he added.

Options for managing slugs are more limited, Michel noted.

"While slugs aren't really widespread, those fields with a history of slugs will likely continue to have slug issues," he said. "This is significant because slugs have a high potential to contribute to significant yield loss for corn and soybeans."

Other invasive and damaging pests that growers can expect this year include the alfalfa weevil, black cutworm and cereal leaf beetle on wheat.

"With the rain that we've had this spring and the rapid alfalfa growth, some growers may be able to cut early for alfalfa weevil rather than spray," Michel said.

With cutworms, he said growers need to pay extra attention to fields that are more susceptible to cutworm problems, such as no-till and/or weedy fields.

"Black cutworm has the potential to be a big problem this year," Michel said. "Some growers may count on seed treatments or Bt hybrids for control, but seed treatments alone won't control cutworm, and not all Bt events work on cutworm, so some growers may think they are protected when they aren't."

Last, adult cereal leaf beetles and their eggs were recently spotted in some wheat fields, which Michel said is a concern as both adults and larvae can cause defoliation. However, since the larvae can do the most damage, growers should scout their fields for larvae, which are small, black and resemble bird droppings, he explained.

Heavily infested fields will have a frosty appearance due to the way this pest feeds. Growers who spot an average of two or more larvae per stem should treat their fields with insecticides to prevent yield loss.

Volume:86 Issue:23

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