How CRISPR could help save crops from pest devastation

Less than a decade after it was first identified in California, an invasive insect called the glassy-winged sniper had turned the bacteria that causes Pierce from a nuisance into a nightmare. The oblong insect, with wings like red-tinted stained glass, is faster and flies farther than native snipers in the state, and it can feed on tougher vines. His arrival, which the state suspects took place in the late 1980s, accelerated the spread of the disease.

Through inspections and targeted spraying of pesticides, the state has largely been successful in containing the invasive sniper to Southern California. But the disease still has no cure, and it is likely to worsen and become more difficult to combat due to climate change.

Researchers are now looking to add cutting-edge technology to California’s anti-Pierce arsenal, modifying the genome of the glassy-winged sniper so that it can no longer spread the bacteria.

Such a solution is possible thanks to the CRISPR gene-editing technology, which has made modifying the genes of any organism increasingly simple. The technique has been used in experiments in cancer immunotherapy, apple breeding and, controversially, human embryos. Today, a growing number of researchers are applying it to agricultural pests, with the aim of controlling a range of insects that together destroy around 40% of the world’s agricultural production each year. If successful, these efforts could reduce reliance on insecticides and provide an alternative to genetically modifying crops.

For now, these genetically engineered insects are locked away in labs around the world, but that’s about to change. This year, an American company plans to start greenhouse tests in collaboration with the United States Department of Agriculture (USDA) on insect pests of fruit rendered sterile using CRISPR. At the same time, scientists from government and private institutions are beginning to learn more about the genetics of pests and to make modifications to more species.

The use of genetically modified organisms remains controversial, and engineered agricultural pests have not yet been approved for widespread release in the United States. A potentially lengthy and ever-changing regulatory process awaits. But scientists say CRISPR has ushered in a critical moment for the use of genetic modifications in insects that impact agriculture, with more discoveries on the horizon.

“Until CRISPR, the technology just didn’t exist,” says Peter Atkinson, an entomologist at the University of California, Riverside, who works on the sniper modification. “We are entering this new era where genetic control can be realistically considered.”

know your enemy

Scientists didn’t know much about the genetics of the glassy-winged sniper until recently. The first draft of its genome was mapped in 2016, by a group from the USDA and Baylor College of Medicine in Texas. But the map had gaps. In 2021, researchers at UC Riverside, including Atkinson, filled in many of these to produce a more comprehensive version.