Environment

Two major crop scourges are hybridizing to produce a new mega-pest

Two major crop scourges are hy...
The cotton bollworm is hybridizing with the corn earworm in ways that could result in a damaging mega-pest
The cotton bollworm is hybridizing with the corn earworm in ways that could result in a damaging mega-pest
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The cotton bollworm is hybridizing with the corn earworm in ways that could result in a damaging mega-pest
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The cotton bollworm is hybridizing with the corn earworm in ways that could result in a damaging mega-pest
CSIRO scientist Tom Walsh
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CSIRO scientist Tom Walsh

Australian scientists have found evidence that two of the world's most damaging pests have hybridized to create a dangerous mega-pest with pesticide-resistant genes. The new hybrid has presently only been identified in Brazil but the researchers warn that its spread throughout the global agricultural community could be devastating.

Helicoverpa armigera, commonly known as the cotton bollworm, and Helicoverpa zea, the corn earworm, are two types of very hungry caterpillar that cause billions of dollars of damage to crops every year. Corn, cotton, tomato and soybean are just some of the many crops these pests can attack, with the cotton bollworm having developed resistance to all pesticides targeted at it.

In 2017, an eight-year project that mapped the entire genome of both caterpillars was completed. The study was designed to help researchers identify specific genes that cause the pests to become resistant to pesticides. A new paper has now been published showing evidence that the two moths are clearly hybridizing in a variety of novel ways.

"No two hybrids were the same suggesting a 'hybrid swarm' where multiple versions of different hybrids can be present within one population," says one of the researchers on the study, Tom Walsh.

CSIRO scientist Tom Walsh
CSIRO scientist Tom Walsh

The researchers suggest that it is too early to identify signs of successful selection in the resulting hybrids but the clear variety of genetic transference found between the two individual pests is a source of great concern. The impact of these evolving pests is already damaging agricultural output in Brazil, and the researchers warn that if these mega-pests establish as a discrete species it would be agriculturally problematic for the entire Americas and beyond.

"They are very impressive little things," Walsh told the ABC. "They can eat a wide range of hosts, seem to survive all our attempts to control them … and that really is my research interest: why isn't it dead when it ought to be?"

The research was published in the journal PNAS.

Source: CSIRO

9 comments
Brian H
Are the any predatory species which mibht control it?
Bob Bolhuis
I wonder if any research is being done that would make pests like these easier to find and/or more desirable to eat for their natural predators? Perhaps alterations that would increase their odor or modify their natural coloration in ways that would allow predators to more easily keep their populations in check.
Singularious
I'm no expert in botany or entomology, but I'm guessing that one difficulty in eradicating these naturally is that they attack the plant internally. In order to be eaten by anything larger, the predator will still destroy the fruit of the plant (boll, ear). That presents a bigger challenge. But I may be incorrect.
ljaques
How does Brazilian farming culture differ from ours? If they stupidly plant the same crop in the same field every year, require constant fertilizer and pesticides for the same pests each year, then we have a real problem. If they rotate crops, till in compost to raise soil value, and use organic practices, then we have an even worse problem globally. It's time to stop worrying about getting the most per-acre output and start using start using more sustainable practices so we stop creating all these problems for ourselves. (This from a conservative Trump voter, folks. ;)
CharlieSeattle
EPA Director Scott Pruitt will be all over this with drastically reduced staff. .................................not!
Martin Kinnaman
Does it surprise a geneticist that screwing with genes of a plant would change the animal that eats it? Is that no playing out with Humans and every other animal on the planet? For all the so called brains that these "scientists" appear to have, to not see the body as a Whole and the planet as a Whole should put their work into perspective, for both the observer and themselves (when they tire of patting themselves on the back for their "work"). Lets see, there are plants that attract predators. Maybe having so many of the same species of plants in an area (factory farming) creates an environment that overwhelms the ability of the predators. At this point in "our" evolution, with cities so large. Why not utilize the hydroponics in or near cities. Then you can factory farm in an enclosed environment. Quit fucking with natural genetics and utilize technologies that allow for mass production in clean, clear environments. Aquaponics might even be better. Re-inventing the wheel sounds fun. Flying even "funner".
EZ
Thank the Lord for Monsanto.
ljaques
CharlieSeattle, why would the EPA tread on USDA territory? Well, except to clean up the toxic mess the geneticists are cooking up in corporate "farm" labs.
Trylon
Sounds like this would be the perfect justification to accelerate the development of RNA-based pesticide as reported here just three days ago: https://newatlas.com/rna-based-vaccines-pesticides/54107/