Biopesticide offers new form of control for bollworm and budworm crop pests
By The U of A System Division of Agriculture
April 9, 2018
- Helicoverpa NPV found in nature as a pest of certain caterpillars
- Bioinsecticide does not kill other pests, harmless to humans
- Download here: https://www.uaex.edu/publications/pdf/AG1306.pdf
(Download this story in MS Word format here.)
LONOKE, Ark. – A host-specific virus is being used to control bollworms and budworms in Arkansas crops.
Helicoverpa nucleopolyhedrovirus, or just NPV, does not affect humans, plants or other insects, including those that are beneficial.
A fact sheet about Helicoverpa NPV is now available online at https://www.uaex.edu/publications/pdf/AG1306.pdf. The fact sheet is a joint publication of the University of Arkansas System Division of Agriculture, Southern Integrated Pest Management Working Group and the Mid-South Entomologists Working Group.
The bioinsecticide has been studied and in use for years. Gus Lorenz, extension entomologist for the University of Arkansas System Division of Agriculture, said there is no shortage of research behind the use of this virus.
“This virus has been around for a long time,” he said. “The specific virus we’re looking at from AgBiTech, we’ve been looking at for about three years.”
The product is widely used and is currently in use in many different countries.
“It’s well adopted in Australia and they’re selling it in South America,” Lorenz said. “It’s used all across the country and they’re pushing it pretty hard in the mid-south.”
The virus only kills bollworm and budworm larvae that are less than a half-inch long and has no effect on later growth stages also known as instars. Because of this, Lorenz said the virus should not be used if a producer finds more than five larger larvae in 25 scouting sweeps of a field.
“The virus doesn’t control the pests at later stages,” he said. “The younger larvae are smaller and more susceptible. 90 percent of what bollworms consume is in the last instars, so you have to catch them before they cause that damage. It’s slow killing, so the last thing you want to do is put it on a late stage larva.”
The virus usually causes death in small larvae within four to six days and can show residual activity through several generations of pests if the conditions are right, according to the publication.
Lorenz said while there is always a possibility for resistance with any insecticide, it is not likely here in the mid-south.
“If you expose larva to it in the front end of the season and the back end of the season, year in and year out, it could build resistance,” he said, “but it’s not probably anything we’re going to experience.”
As stated in the publication, the virus is safe for tank-mixing. However, along with some other mentioned precautions, Lorenz warns against mixing with high pH water.
“Water with high pH breaks down the matrix of the virus,” he said. “It’s extremely important that it’s not mixed with water with a pH of eight or higher.”
There are restrictions on when to use Helicoverpa NPV in relation to time of year.
Mention of product names does not imply endorsement by the University of Arkansas System Division of Agriculture.
To learn more about using this tool, contact your county agent or visit www.uaex.edu.
About the University of Arkansas System Division of Agriculture
The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on five system campuses.
The University of Arkansas System Division of Agriculture is an equal opportunity/equal access/affirmative action institution. If you require a reasonable accommodation to participate or need materials in another format, please contact your county extension office as soon as possible. Dial 711 for Arkansas Relay.
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Media Contact: Mary Hightower
Dir. of Communication Services
U of A System Division of Agriculture
Cooperative Extension Service