Soybean bollworms thriving in the heat, threatening crop

By Keith Boles - bio | email feedback

CRAIGHEAD COUNTY, AR (KAIT) - The heat is posing yet another threat to much of the Central US, especially soybean producers.

Bollworms are not showing a slowdown like in normal years. University of Arkansas extension officials say traps are catching record numbers of egg-laying moths.

"Our state entomologist says this is one of the worst bollworm flights he has seen since he has been working and that's been a number of years." Craighead Extension agent Branon Thiesse told me. He held a number of dead moths in his hand as we stood next to one of his traps in East Craighead county.

"We've had big bollworm flights before but the thing that sticks out this year is that they never seem to cease it's just a constant number." Thiesse says his trap numbers are exceptionally high.

"Ours have been running to a hundred, 110 per trap but those numbers never really drop down in low levels. It's just a constant number. Every week we're catching 50 to 100 moths in a trap every 2 or three days and the number never grows down."

The moths lay the eggs that grow into the worms which grow into moths and start the cycle over again.

A new report from the U-of-A Extension says this is the worst infestation in years.

As moths the worms migrate from the South often attacking corn first then moving onto cotton and soybeans. While cotton plants can genetically fight the worms off, soybeans are quite vulnerable and tasty.

Thiesse, "They defoliate and they can also get down and eat the pods and blooms as they progress on the plant."

This of course can have an effect on overall yields at harvest time.

As we stood in the field the drone of ag planes could be heard from nearly all sides. At our feet a large poly pipe was gushing water between the rows.

Applying insecticide is important followed up by sufficient watering.

Thiesse, "We want to make sure you use high volumes of water to make sure you get the insecticide down in the plant. Because these moths lay these eggs down in the shady part of the plant down where it's cool."

Thiesse says scouting is very important because if you treated one field and haven't found any insects they might be in the field next door. So you need to keep a constant watch on your fields until they are harvested.

To be vigilant, farmers use shake sheets and sweep nets to look for the pests.

Thiesse, "Treat the field as needed and then go back out 3 or 4 days later and check again because there has been a progressive egg lay and you'll have more worms. Just because you spray one time doesn't mean you have solved your problem."

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