Want your bodyguards to stick around? Give them lodging. Some plants seem to do just that in the form of tiny pockets and hair tufts on the undersides of leaves, offering the shelter necessary to house a population of plant-protecting bugs, report researchers at the University of California, Davis.
By simulating these naturally occurring shelters, known as "leaf domatia," on cotton plants, the researchers reduced the populations of cotton-eating spider mites and boosted cotton yield by 30 percent. These results, offering the first experimental evidence that plants and certain bugs both benefit from the presence of domatia, are reported as scientific correspondence in the June 5 issue of the journal Nature.
"Domatia are wildly common and take on many forms, ranging from very simple cavities to complex hair-tufted structures," explained Anurag Agrawal, a UC Davis doctoral candidate, who conducted the study with entomology professor Richard Karban. "We think that predatory insects and mites use domatia both for protection from their enemies and for improved microclimatic conditions," he said.
Domatia were originally described in the late 1800s by Swedish naturalist Axel Lundstrom, who proposed that these structures offer mutual benefits to both the plants and to certain protective insects and mites. His notion lay dormant until about a decade ago when a few research groups around the world began to probe its validity.
One of the striking features of domatia is that they seem to be inhabited strictly by insects and mites that feed on other bugs rather than on plants, further evidence of a mutually beneficial relationship between plants and the domatia residents.