The Colorado potato beetle, Leptinotarsa decemlineata’s rapid spread, hardiness, and recognizable tiger-like stripes have caught global attention since it began infesting potatoes in the 1800s.
Photo: Zach Cohen
Scientists led by Professor Sean Schoville, of the University of Wisconsin–Madison's Entomology Department, have discovered the design modifications that enable the Colorado potato Beetle to resist just about all the insecticides humans have developed against it. As its name implies, the Colorado potato beetle is a major pest on the potato plant and can devastate crops. In the UK, it is considered so serious that it is compulsory to notify the police if you detect the adult or larval form of the beetle.
The new research shows that the beetle has evolved a whole range of genetic adaptations that give it the capability to quickly evolve resistance in a local population. As any intelligent [sic] design advocate will tell you, this doesn't happen by natural selection selecting from chance mutations, but must be intelligently designed by a magic designer. If this were true, it would raise the question of why this putative magic designer designed this pest on an essential human food crop in the first place, and now seems to have given it the ability to resist anything we can combat it with.
The researcher's findings are published, open access, in the journal, Molecular Biology and Evolution.
According to the University of Wisconsin-Madison's press release accompanying the publication:
This beetle was one of the first to be attacked with chemicals in the modern era, and it’s been very successful at evolving past those attacks. For other insects we’re hoping to control, there’s lessons to be learned from studying this pest. What mechanisms does this insect use to get past these insecticides?
The genes that evolve are well known to be involved in insect resistance. But what’s interesting is that different populations are altering different parts of genes or different genes in the same pathway
More sophisticated models might help us learn how different management techniques affect the beetle’s evolution. That might allow us to change our management style to slow it down.
The genes that evolve are well known to be involved in insect resistance. But what’s interesting is that different populations are altering different parts of genes or different genes in the same pathway
More sophisticated models might help us learn how different management techniques affect the beetle’s evolution. That might allow us to change our management style to slow it down.
Professor Sean Schoville, project leader
Department of Entomology
University of Wisconsin–Madison, Madison, WI, USA
Department of Entomology
University of Wisconsin–Madison, Madison, WI, USA
The Colorado potato beetle has evolved resistance to more than 50 different kinds of insecticides, making the insect a “super pest” that wreaks havoc on potatoes around the world. New research finds that the beetle achieved this feat largely by turning to a deep pool of diversity within its genome, which allowed different populations across the U.S. to quickly evolve resistance to nearly anything humans have thrown at it. The pest’s wealth of diversity and arsenal of existing resistance genes will likely make it hard to control in the future, regardless of what new insecticides 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 first sequenced the Colorado potato beetle’s genome in 2018. Since then, they’ve 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 U.S. 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 says, that even a brand-new insecticide would keep the pest in check for long.
But armed with the knowledge of how the Colorado potato beetle has sidestepped our attacks, future research might help produce creative strategies to keep pace with this nemesis.
Copyright: © 2022 The authors. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.AbstractTo add to the embarrassment of Creationists faced with this example of the malevolent intent of any intelligent designer that could come up with this apparent redesign of the Colorado potato beetle’s genome, there is yet more bad news in this publication.
Insecticide resistance and rapid pest evolution threatens food security and the development of sustainable agricultural practices, yet the evolutionary mechanisms that allow pests to rapidly adapt to control tactics remains unclear. Here, we examine how a global super-pest, the Colorado potato beetle (CPB), Leptinotarsa decemlineata, rapidly evolves resistance to insecticides. Using whole-genome resequencing and transcriptomic data focused on its ancestral and pest range in North America, we assess evidence for three, nonmutually exclusive models of rapid evolution: pervasive selection on novel mutations, rapid regulatory evolution, and repeated selection on standing genetic variation. Population genomic analysis demonstrates that CPB is geographically structured, even among recently established pest populations. Pest populations exhibit similar levels of nucleotide diversity, relative to nonpest populations, and show evidence of recent expansion. Genome scans provide clear signatures of repeated adaptation across CPB populations, with especially strong evidence of selection on insecticide resistance genes in different populations. Analyses of gene expression show that constitutive upregulation of candidate insecticide resistance genes drives distinctive population patterns. CPB evolves insecticide resistance repeatedly across agricultural regions, leveraging similar genetic pathways but different genes, demonstrating a polygenic trait architecture for insecticide resistance that can evolve from standing genetic variation. Despite expectations, we do not find support for strong selection on novel mutations, or rapid evolution from selection on regulatory genes. These results suggest that integrated pest management practices must mitigate the evolution of polygenic resistance phenotypes among local pest populations, in order to maintain the efficacy and sustainability of novel control techniques.
Pélissié, Benjamin; Chen, Yolanda H; Cohen, Zachary P; Crossley, Michael S; Hawthorne, David J; Izzo, Victor; Schoville, Sean D; (2022)
Genome Resequencing Reveals Rapid, Repeated Evolution in the Colorado Potato Beetle
Molecular Biology and Evolution 39(2); DOI: 10.1093/molbev/msac016
Open access
Reprinted under a Creative Commons Attribution-NonCommercial 4.0 International license (CC BY-NC 4.0)
For those who have been excitedly awaiting the overthrow of the scientific theory of evolution and its replacement with a Bronze Age superstition, any day now real soon, since about 1940, there is the added disappointment that there is again, as with all biology papers, no sign of this happening. Instead, we see a heavy dependence on the TOE to explain these adaptations and no sign whatsoever of attributing them to magic.
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