Bioinsecticide helps farmers fight pest caterpillars
It’s a small dose because ultimately the caterpillars in your field do the work for you as they arrive, noted Marcon. “Once the first caterpillars are infected, it becomes a COVID-like situation, with each caterpillar infecting many more,” she said. “Ten days after a spray you can have 100 times more virus particles in a field, which is the opposite of a chemical insecticide, which are at their highest concentration on the day of spraying, and then it goes down.”
IN THE FIELD
Entomologist Gus Lorenz, of the University of Arkansas Extension, was skeptical when he started testing Heligen in his plots in 2010. But after about seven days his team started tracking dead caterpillars and afterwards of 14 days, they stopped counting, because this generation of podworm was dying out. .
He was shocked to find the virus was still circulating when a second generation of caterpillars arrived – 32 days later. “There were dead worms everywhere – in every patch we had,” recalls Lorenz. “The virus had spread all over the field, through all of our plots.” Lorenz has so far found NPVs effective in controlling pod worms for up to 40 days after application in his trials.
In fact, the virus’s easy mobility subsequently caused problems for Lorenz, when he traveled to research plots dedicated to synthetic insecticide trials, ultimately ruining that data by reducing pest pressures. Eventually, one of its graduate students, Joseph Black, discovered that 21 different insect species helped escort the virus through fields each season. “They come in, feed on a dead worm, land and carry that virus with them every time they move,” Lorenz said. “It was kind of a revelation.
See the work published by Blacks here: https://scholarworks.uark.edu/…
The idea of the bugs doing the work for you immediately appealed to Adam Baldwin, who was battling growing infestations of headworms in his sorghum fields in McPherson, Kansas about six years ago.
Not only did pyrethroids not consistently work against headworms, their application would kill beneficial insects that helped keep sugarcane aphids at manageable levels, recalls Baldwin. A group of visiting Australian farmers suggested VPN-based insecticides and Baldwin went on a mission to find it in the United States
“I was the first farmer in Kansas to use it – you can put it on my gravestone,” he joked. “I had to drive all the way to Oklahoma to get it.” Since then, he estimates that up to 50% of sorghum farmers in his region now regularly use NPV-based bioinsecticides, as crop scouts and cooperative workers realized his success and began to advocate. for their use.
There is a learning curve to using organic products for pest control, the two farmers noted. First there are the logistical issues, with pH sensitivity (Appleberry tests its tank mixes to make sure they’re safe) and temperature restrictions.
“You can’t throw it in the back of a pickup and drive around for two to three days and expect it to work,” Appleberry explained. “We keep it in the freezer until we need it.”
A bigger shift in mindset is also needed, Baldwin said. Most farmers are used to the wait-and-see approach to pest spraying, as well as to fast-acting synthetics. “You light up, you let the population increase, then you spray worms when they’re big and easy to see, and they died that day,” Baldwin said.
But the bioinsecticide needs time to create a cycle of caterpillars that die off and infect others. This means that applications need to be launched early, for low thresholds of small worms, and can take a week to tighten up control, AgBiTech’s Castro said.
“It’s a change in mindset,” admitted Baldwin, who now begins to search for tiny headworms immediately after pollination. “But Heligen is cheap and milo is very valuable right now, so if I find worms, why take the risk?”
The caterpillar pressures are strong and consistent enough in southeast Arkansas soybeans that Appleberry has found that regular application at flowering works best for her farm, although podworms are then hard to find. Waiting for the organic product to do its job takes patience – it’s not always his strong suit, he admits.
“One of the best ways to be patient is to think about spending $ 5 an acre on Heligen for a month-long checkup, versus $ 15 for an insecticide application every 7-10 days,” a- he said wryly.
When Lorenz examines the current insect control in Midsouth – growing insecticide resistance and Bt resistance, increasingly shrinking toolkit of chemicals and many pests – he thinks bioinsecticides are a safe bet.
“I think it’s the wave of the future,” he said. “It has been underused so far, but it’s becoming more and more obvious to me that they will play a big role in the future.”
Corteva Agriscience agrees, said Frédéric Beudot, who heads Corteva’s global biologics portfolio, a new area of growth for the company. Corteva is rolling out its Hearken bioinsecticide for use in corn, cotton and sorghum, and the company will also have its sales teams showcasing samples of it next year, Beudot said.
“As the old chemistries that we relied on to delay resistance are being phased out, we have fewer and fewer tools,” he said. “And new insecticides and traits are under increasing pressure, so we need to find new sources with completely different modes of action to reduce insect populations without putting more pressure on those valuable modes of action that we have. remain. “
AgBiTech is also looking to expand its presence in the United States by expanding into the row crop markets, as well as diversifying into specialty markets such as sweet corn, hemp, peanuts, strawberries and tomatoes, Castro said. Heligen and Fawligen are also certified organic herbicide options, and Surtivo and Chrysogen are also eligible for this certification, Castro said.
Learn more about AgBiTech’s VPN-based insecticides here: https://www.agbitech.com/…
See Corteva’s press release on Hearken here: https://www.corteva.us/…
Emily Unglesbee can be reached at: [email protected]
Follow her on Twitter @Emily_Unglesbee
(c) Copyright 2021 DTN, LLC. All rights reserved.