The Colorado Potato ‘Super beetle’ is ‘Immune’ to More Than 50 Types of Insecticides
The University of Wisconsin–Madison experts in entomology led an in-depth sequencing of the Colorado potato beetle’s genome starting with 2018, to understand how this “superbug” can overcome new insecticides as quickly as it does.
New research done by Sean Schoville, a University of Wisconsin–Madison professor of entomology and his team, finds that the Colorado potato beetle achieved this feat largely by turning to a deep pool of diversity within its genome. This allowed different beetle populations across the US to quickly evolve resistance to nearly anything humans have thrown at it.
According to Phys.org, the pest’s wealth of diversity and arsenal of existing resilient genes will likely make it hard to control in the future, regardless of what new molecules researchers develop. But the new understanding of the pest’s genomic resources could help scientists design management systems that keep it in check.
Schoville’s team probed the genome to understand how the insect can overcome new insecticides as quickly as it does. To do so, they sequenced several dozen beetles from across the US. These regional populations vary in what pesticides they are resistant to and where they came from, which can give clues to the evolutionary history of the pest.
The scientists discovered that these different regional groups evolved so quickly because their parent populations already had the genetic resources necessary to overcome insecticides.
This rapid evolution based on a wealth of existing genetic diversity is at odds with an older model of evolution that assumed rare mutations have to slowly arise in a population. While new mutations do develop and can contribute to insecticide resistance, the potato beetle’s rapid response to new chemicals in different parts of the country can be explained only by its existing diversity.
The findings are unwelcome news for farmers and scientists hoping to turn the tide on the potato beetle’s attacks. It seems unlikely, Schoville added, that even a brand-new insecticide would keep the pest in check for long.