A virus transmitted during mating sterilizes corn earworm moths and wipes out generations of the pest.

Corn earworms go by many names: cotton bollworm, tomato fruitworm, soybean podworm, and vetchworm. No matter what you call this pest, its damage is obvious.

The caterpillar eats and contaminates over 46 varieties of cultivated crops – in particular, corn ears, cotton bolls, bean pods, and tomato fruit. Some corn earworms have shown resistance to pesticides and crop toxins, which costs farmers in excess of $2 billion per year in crop loss and control costs.

Lepidext, a start-up out of Lexington, Kentucky, has identified a virus strain with the ability to sterilize 100% of corn earworms. It’s called Vanesco45, a Latin term meaning “to vanish.” The infected moths transmit the virus to their eggs, hatch sterile adults, and cause subsequent generations to disappear.

According to Kendra Steele, cofounder and chief scientific officer, “Organic farmers and other producers have limited options to control the corn earworm. We have designed and developed a non-GMO, chemical-free method that is going to be much cheaper than pesticides, and it’s safe because it’s contained within the moth.”

How it Works

The product is a container of pupae infected with Vanesco45. Once the pupae are released into a wild colony and develop into sterile moths, they mate, and the female transmits the virus to her eggs, resulting in sterile offspring.

“One female moth can lay 3,000 eggs in her lifetime. If you start with only one female and she has just 1,500 females that each lay 3,000 eggs, that’s 4.5 million eggs. With our technology, it’s zero,” says Steele.

Because Vanesco45 remains in the moths, there is nothing to spray and no risk to humans, birds, bats, or honey bees. The virus is species-specific, so even if people or beneficial insects are exposed, there is no risk of contraction. Birds and bats are unaffected for the same reason, even if they consume an infected corn earworm.


In lab studies, Vanesco45 achieved 35% reduction of moths in one generation and a complete collapse in the second generation.

Lepidext will focus next on field studies to establish the technology, then optimize the delivery and production system by 2021.

The success of Vanesco45 has led the team to consider delivering the virus to the old-world cotton bollworm, a pest that has invaded Brazil and was found in Florida in 2015. Since this bollworm mates with the corn earworm, Lepidext could stave off another giant pest problem for the United States.

“Our ultimate goal is to help farmers,” says Steele. “We understand that the corn earworm is a big problem, and it is becoming worse each year. The time is coming where farmers are going to need something new for the corn earworm before it becomes an extreme megapest. We’re trying to do that.”

About the Company

Founders: Kendra Steele, Angelika Fath-Goodin, Bruce Webb

Headquarters: Lexington, Kentucky

Website: lepidext.com

Background: Lepidext’s first product, Vanesco45, is a biopesticide containing a species-specific virus that is safe, nontoxic, and transmitted during mating to sterilize corn earworm moths that become infected. It is possible to eliminate entire colonies of earworms by the second generation due to effective virus infection of the moths during mating.

Funding: Lepidext has received $350,000 in funding without equity exchange, and the founders have invested an additional $150,000 into the company.

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