A stunning new wireworm seed treatment does more than stun


Good detective work is essential to solving this pest problem.

“Wireworms are an ongoing concern,” said Kevin Wanner, Plant Sciences and Plant Pathology Associate Professor at Montana State University. “Wireworms, the larval stage of click beetles, have a long life cycle of two to seven or more years in the soil.”


Many stages of wireworm larvae are active in the field as they progress into a pupae and adult click beetles. And the populations expand exponentially: Two adult click beetles in a field in year one grow to more than 200 adults and 1,000 wireworms by year three.  In fact, growers can face a loss of more than 50% of seedlings, and those that survive may be stunted.


But many growers are still not fully aware of the presence of wireworms or the extent to which they can impact crops.


What you can’t see can hurt.

“A lot of growers tend to be more reactive than proactive when wireworms are below ground,” said Wanner. “Often the grower doesn’t really know they have a problem in their field until they see the damage. When the problem gets out of control, growers are replanting two, three times and still not getting a very good yield. It can become almost a total crop loss in the severe cases.”


Even when a grower sees the above-ground symptoms of wireworms, sometimes they’re confused with other pests. “It might be cutworms or abiotic factors too,” said Wanner. “Any factor that would cause poor stand development early in the spring could be confused with wireworm damage.”


Are wireworms the culprit?

If growers see above-ground symptoms, the first, most important step is to determine the cause by scouting or placing bait traps.


Since wireworms feed on seedlings, look for failed germination, poor early plant stand and even brown spots on the plant roots. Later on, look for flag leaves dying off. And in heavily infested areas, there will likely be more weeds in the stands.


“You can go out to those poor areas and dig around the roots and find the wireworm larvae,” said Wanner. “That’s not going to give you any options for treatment in that year, but because of the long life cycle of wireworms they’re often considered to be a pest of the site. Meaning once you have them there, you’ll usually have them for years.”


Using bait traps gives growers a good assessment of what pressure they have in specific areas. Set the bait traps about three weeks before planting; that gives the wireworms time to get into the traps.


“Take a cup of grain, it could be wheat or corn, and soak it overnight,” said Wanner. “Then place it in your field six inches deep. As that seed germinates, it’s going to attract wireworms. It takes seven to 14 days to germinate. Then pull out the traps and count the number of wireworms.”


Getting wireworms “drunk” isn’t the best way protect your wheat.

When wireworms have been diagnosed as the problem, the primary recommendation has always been insecticides or seed treatments. However, the leading treatment today — neonicotinoid treated seeds — only causes intoxication of the wireworm. This “drunk” effect can protect initial stand establishment and seedling development, but the lack of direct mortality allows the larval development and life cycle progression to continue, leading to population growth and continued crop damage.


“Producers have been waiting for a product that has a mortality effect. I think that will be a welcome addition to the products that are available,” said Wanner.


For the 2021 growing season, BASF anticipates bringing its two newest seed treatments to market — Teraxxa™ seed treatment and Teraxxa F4 seed treatment — giving growers a powerful new weapon that does what no current treatment can do: induce mortality in wireworms. And not just temporarily stunning the pest, but actually eliminating them for in-season control and population reductions.


“A new insecticide with a mode of action that increases wireworm mortality and decreases those field populations will have a very significant impact in Montana and the  western U.S.,” said Wanner.


With the addition of these two innovations, BASF will be offering a complete seed treatment lineup in cereals to battle pest and disease threats.


To learn more about Teraxxa seed treatment and Teraxxa F4 seed treatment, reach out to your local BASF representative.


Always read and follow label instructions. Teraxxa products are not registered and not available for sale. This article is provided for educational purposes only and is not intended to promote the sale of these products. Any sale of these products after registration is obtained shall be based solely on the EPA approved product label, and any claims regarding product safety and efficacy shall be addressed solely by the label. Teraxxa is a trademark of BASF. © 2020 BASF Corporation. All rights reserved. * Disclaimer: Photos from 2020 Rosalia WA, The McGregor Company trials. 


About BASF’s Agricultural Solutions division

With a rapidly growing population, the world is increasingly dependent on our ability to develop and maintain sustainable agriculture and healthy environments. Working with farmers, agricultural professionals, pest management experts and others, it is our role to help make this possible. That’s why we invest in a strong R&D pipeline and broad portfolio, including seeds and traits, chemical and biological crop protection, soil management, plant health, pest control and digital farming. With expert teams in the lab, field, office and in production, we connect innovative thinking and down-to-earth action to create real world ideas that work – for farmers, society and the planet. In 2019, our division generated sales of €7.8 billion. For more information, please visit www.agriculture.basf.com or any of our social media channels.


About BASF

BASF Corporation, headquartered in Florham Park, New Jersey, is the North American affiliate of BASF SE, Ludwigshafen, Germany. BASF has more than 18,800 employees in North America and had sales of $18.4 billion in 2019.  For more information about BASF’s North American operations, visit www.basf.com/us.


At BASF, we create chemistry for a sustainable future. We combine economic success with environmental protection and social responsibility. More than 117,000 employees in the BASF Group work on contributing to the success of our customers in nearly all sectors and almost every country in the world. Our portfolio is organized into six segments: Chemicals, Materials, Industrial Solutions, Surface Technologies, Nutrition & Care and Agricultural Solutions. BASF generated sales of €59 billion in 2019. BASF shares are traded on the stock exchange in Frankfurt (BAS) and as American Depositary Receipts (BASFY) in the U.S. Further information at www.basf.com.