Less than a decade after it was first identified in California, an invasive insect called the glass-winged warbler has turned the bacteria that causes Pierce’s disease from a nuisance into a nightmare. The oblong beetle, with its red-tinted glass-like wings, is faster and farther flying than the sharp beetles native to the state, and it can eat harder vines. Its arrival, which the state suspects was in the late 80s, accelerated the spread of the disease.
RODRIGO KRUGNER/USDA-ARS
Through targeted pesticides and inspections, the state has largely been able to curb invasive snipers in Southern California. But this disease still has no cure, there is a risk of getting worse and more difficult to treat due to climate change.
Researchers are now looking to add cutting-edge technology to California’s arsenal against Pierce, by altering the glass-winged sniper’s genome so that it can no longer spread bacteria.
Such a solution is made possible by the gene editing technology CRISPR, which makes it simpler to edit the genes of any organism. This technique has been used in experiments in Cancer immunotherapyapple breeding, and—controversial—human embryo. Now, more and more researchers are applying it to agricultural pests, aiming to control a variety of insects that together kill about 40% of global crop production per year. If successful, these efforts could reduce dependence on pesticides and provide an alternative to genetically modifying crops.
For now, these gene-edited insects have been shut down in labs across the globe, but that’s poised to change. This year, an American company is scheduled to start greenhouse test in association with the United States Department of Agriculture (USDA) on insect pests of CRISPR-sterilized fruit. At the same time, scientists at government and private institutions are beginning to learn more about the genetics of pests and make edits in more species.
The use of gene-edited organisms remains controversial, and the edited agricultural pests have not yet been approved for widespread release in the United States. A potentially lengthy and still evolving regulatory process awaits. But scientists say CRISPR opens a pivotal moment for the use of gene editing in insects with an impact on agriculture, with more discoveries ahead.
“Until CRISPR, the technology wasn’t there,” said Peter Atkinson, an entomologist at the University of California, Riverside, who is working on modifying snipers. “We are entering a new age where genetic control can be realistically contemplated.”
Know your enemy
Scientists did not know much about the genetics of the glass-wing gunner until recently. The first draft of its genome was outlined in 2016, by a team at the USDA and Baylor College of Medicine, Texas. But the map has gaps. In 2021, researchers at UC Riverside, including Atkinson, filled in a lot of them to create a more complete version.
