Many crop plants already produce small amounts of terpenes, including corn (maize), apples, beans, cucumbers, and cotton.
Bouwmeester adds that bodyguard-attracting compounds work best when emitted by the plants themselves. Spraying crops with similar man-made chemicals would be less effective given the delicate balance of interactions between a plant, pests, and predators.
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"You only want to attract these predators at the exact moment [their] food source, such as the spider mite, is there," he added.
In the wild, plants lure a range of predatory bugs that perform a vital pest control service. These helpful dinner guests include aphid-chomping ladybugs and parasitic wasps that lay eggs inside caterpillars.
Pickett of Rothamsted Research says plants are often highly sophisticated in their signaling. The plants can tailor their messages for specific predators depending on which pest species is taking a bite out of them.
For instance, he says, "There are three aphid species that attack beans: the vetch aphid, the black bean aphid, the pea aphid.
"But a particular parasitoid [a parasite that kills its host] can only develop in the pea aphid. And that parasitoid can tell from the signals coming out of the bean plant whether it's only the pea aphid that's there."
Crop Yields
Pickett says the Dutch-led team's research may allow humans to harness plant-bug interactions to improve crop yields.
"Nature's only evolving to create a balanced situation," he said. "But we need to create food, which inevitably disrupts that balance. As soon as you grow a monoculture you need pest control, so these new approaches are going to be very important."
"There's a tremendous demand for alternatives to pesticides, not only because of people's fear of pesticides, but also because insects develop resistance to them," Pickett added.
But many advocacy groups have heavily criticized development of genetically modified crops. The man-made plants pose a serious risk to the natural environment, they say.
Pickett says this latest plant should be no cause for alarm.
"Nobody needs worry because all the genes are from the plant kingdom—it's just that [the researchers have] done some genetic tricks," he said.
The research could also help create a new generation of bodyguard-attracting crops without high-tech genetic modification, according to study co-author Bouwmeester.
He says a major goal of the team's research is to identify which plant chemicals act as bug attractants.
Once these compounds are identified, he says, "We think that with normal, traditional breeding it would as well be possible to improve the ability of plants to lure predators."
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