Sharpshooter's secret solved
June 9, 2006
• Breakthrough could lead to control
• Key is ‘symbiotic’ bacteria
Glassy-winged sharpshooter—notorious carrier of the microbe that causes Pierce's disease of grapes. (USDA photo by Peggy Greb)
The Achilles heel of the glassy-winged sharpshooter, an insect pest threatening Central Valley vineyards, has been discovered says a scientist at the University of California, Davis.
The housefly-like insect, which kills the vines it feeds on, depends on two bacterial passengers to supplement its diet -- and those bacteria rely on the insect, and each other, for vital nutrients, according to a new study.
Understanding what the symbiotic bacteria do for the host could lead to new methods for controlling the insect pests, says Jonathan Eisen, who recently joined UC Davis' Genome Center from The Institute for Genomic Research in Rockville, Md.
Sharpshooters feed by tapping into the xylem, the water transport system that runs through woody parts of plants. But xylem fluid is thin, watery stuff with few nutrients. So the sharpshooter must make up its diet in other ways.
The sharpshooter carries two types of bacteria that the researchers think make nutrients in exchange for living space: Baumannia cicadellinicola -- named for Paul Baumann, professor emeritus of microbiology at UC Davis and an authority on such symbiotic bacteria -- and Sulcia muelleri.
In addition to Eisen, the members of the research team include Dongying Wu, Sean Daugherty, Kisha Watkins, Hoda Khouri, Luke Tallon and Jennifer Zaborsky at The Institute for Genomic Research; Susan Van Aken and Grace Pai at the The Institute for Genomic Research.; and Helen Dunbar, Phat Tran and Nancy Moran at the University of Arizona.
The research is published in the June issue of the journal Public Library of Science and funded by a National Science Foundation grant to Ms. Moran.