Wireworms: They’re hungrier than ever.

It sounds like science fiction, but it’s science fact. Wireworms have been infiltrating fields for decades, causing unwanted damage in growers’ crops. It’s a tough pest to manage, as they eat almost anything in the soil: decomposing plant material, seeds and germinating seedlings.


Wireworms, the larval stage of click beetles, have been on the radar of growers and crop scientists dating back to the early 20th century. However, the development of effective organochlorine insecticides pushed the focus on the pests to the back burner. The products were so successful in managing wireworms, research dwindled for years.


“Now, researchers are starting to see more and more wireworms infesting fields. Even neonicotinoid insecticides can’t hold them back – when those populations get built up in a field, they’ll eat right through the seed coating,” said Dr. Ruhiyyih Dyrdahl-Young, BASF Technical Representative for the northern Great Plains.


The problem is compounded when adult click beetles from surrounding permanent habitats — grassy ditches, pasture and undisturbed field borders — start to invade the vulnerable crop fields. The wireworm population then has the chance to explode exponentially underground.


Once wireworms make their way into a field and reach significant populations, they pretty much move in permanently, and you are likely to have them year after year. You may see symptoms such as:

  • Stunting damage: Wireworms will chew into wheat sprouts forming brown spots on roots at the base of the stem.
  • Wilting or dying flag leaves.
  • Patchy, bare areas on the field. Wireworms thrive in both dry land and irrigated soil.

“Since the wireworm has such broad eating habits, crop rotation and cover crops are not always the most effective tools to combat them,” said Dyrdahl-Young. “The best way to minimize the pest’s damage is to scout the field in early spring.”


You can scout before or after crop emergence to investigate whether the field is being damaged by wireworms. Heading to a patchy field and digging up roots will often reveal the pests. Other means include planting bait or a stocking trap into the soil to attract them.


If wireworms are discovered in the soil, you should collect a few, store them in alcohol, and send them to a local entomologist to determine the species. Once the species is determined, it is easier to pick the most effective seed treatment for the job.


“Even though wireworms are currently a problematic pest,” said Dyrdahl-Young, “We have Teraxxa™ insecticide seed treatment coming soon with a novel mode of action to control wireworm populations.”


It’s lights out for wireworms, and in this science fact story, that’s a happy ending.


Reach out to your local BASF representative to learn more about wireworm symptoms and damage.


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