What’s Buggin’ Your Fields?
Misidentification proves a costly mistake, valuable lesson learned.
By Amanda Huber
In 2008, peanut fields were marched upon with a fierce vengeance by tobacco budworm. They struck early and repeatedly, with three destructive generations of budworms occurring in many fields. Adding insult to injury, many producers treated the pest incorrectly, costing them in more ways than one. It should be a good learning experience.
How Could You Know?
However, Adams says, there was an expensive lesson learned because the early treatments were made with an ineffective insecticide for the budworms. The reason, unfortunately, was that most producers thought it was a different pest.
“Most growers were thinking that they had a corn earworm infestation and used a pyrethroid without success. Pyrethroids are not effective against budworms, and the budworm, to the naked eye, looks identical to the corn earworm.”
Besides the pests looking identical, Adams says it was an easy mistake because budworms have never been an economic issue in peanuts before 2008. “Let’s hope last year is not the beginning of a trend.”
“It was somewhat spotty, but where it occurred, it created some control problems,” Weeks says. “It was primarily cutworms and tobacco budworm populations.”
As was the case in Georgia, Weeks says tobacco budworms were treated in many cases with pyrethroid chemistry, which did not work.
“Tracer was effective, but in short supply in most areas,” Weeks says. “We wound up getting effective results with Steward or Lannate for these particular pest problems.”
Risk Indexes Working Well
“The increased use of resistant peanut cultivars and planting-date changes to avoid thrips damage along with adoption by growers of the TSWV risk index, now a part of Peanut Rx, has made a big difference in damage to peanut yields by TSWV,” he says.
Rick Brandenburg, North Carolina State University Extension entomologist, says the adoption of practices shown to lessen the incidence of TSWV has helped tremendously in his area as well.
“Thrips have always been a problem in the Virginia-Carolina area because we have a shorter growing period, and they stunt the peanut plants. Our earliest-planted peanuts have a tendency to get hit pretty hard.
“Our farmers have done a very good job using our tomato spotted wilt virus index (modified from Georgia), so we have been very fortunate with regard to the level of virus we have seen in the last six years,” he says. “I think our growers are following the rules, and this has really helped.”
Brigade received a label for thrips, leafhoppers, threecornered alfalfa hoppers and some foliage-feeding worms. Dimilin is now labeled for velvetbean caterpillars, armyworms and lesser cornstalk borers. Intrepid received a label for beet armyworms.
Remembering the lessons learned from 2008, producers should be absolutely certain that they know the pest problem in their field before deciding on what product to use for treatment. A phone call to an Extension agent or entomologist and even a field visit is a small price to know the treatment applied will work on the specific pest causing the problem.