November 28, 2001

POSSIBLE SHARPSHOOTER INSECT PEST HABITATS MAPPED FROM AIR & SPACE

NASA satellite and aerial images of California?s Monterey County vineyards are helping local officials identify vineyards at risk of invasion by the glassy-winged sharpshooter insect pest.

The gluttonous pest has caused widespread damage to Southern California's vineyards, but has not yet invaded Monterey County. The glassy-winged sharpshooter is blue-green, about a half inch long and is famous for a stylus-like drill that the insect uses to draw moisture from plants.

"We're using remotely sensed imagery to map vineyards and other sharpshooter habitats," said Lee Johnson, a California State University, Monterey Bay (CSUMB) research scientist. Johnson is based at NASA's Ames Research Center in California's Silicon Valley and is technical advisor for the effort. The pest often lives in orchards and along riverbanks, ditches and ponds and may threaten adjacent vineyards. "The maps will be used to determine the most effective places for agricultural officials to place traps to monitor for the sharpshooter," Johnson said.

"We created a defense map for the Monterey County Agriculture Commissioner's Office to combat any invasion by the sharpshooter," said Bay Area Shared Information Consortium (BASIC) president David Etter. "We identified the habitats of these rascals. They like to hang out on stream banks, in citrus groves and even in oak groves," he said. The insect sucks moisture from the heavy stalk of grapevines, and in the process can deposit a bacterium that causes Pierce's disease. Afflicted plants are unable to draw ground moisture or nutrients, Etter said. The plant then dies.

"Each adult glassy-winged sharpshooter sucks out 200 to 300 times its body weight in water every day. This is equivalent to an adult human drinking 4,300 gallons (16,340 liters) of water per day," said Dr. U Win, author of a report about the project to map the pest's potential habitats. He also is a research associate at the CSUMB Spatial Information, Visualization and Analysis Resources (CSUMB-SIVA) Center.

The pest feeds on more than 70 species of plants and is active all year. In addition to grapevines, the sharpshooter lives on citrus, avocado, macadamia, eucalyptus, crape myrtle, oleander, oak, sycamore, sumac and other plants. As of now, the insect has infested the entire counties of Los Angeles, Orange, Riverside, San Bernardino, San Diego, Ventura and parts of Butte, Contra Costa, Fresno, Kern, Imperial, Sacramento, Santa Barbara and Tulare counties, according to Win.

"The Agriculture Commissioner's Office will place insect traps strategically in the sharpshooter habitats, and mark their positions on our maps with global positioning system (GPS) technology," Etter said. The maps will make it easy to identify which vineyards are most vulnerable should there be a sharpshooter invasion, officials said.

The researchers combined LANDSAT satellite pictures with high-altitude aerial photos, and verified types of plants depicted by using ground-gathered data to make an accurate computerized map of the vineyards, orchards and other areas under study. "'Ground-truthing' was essential for the verification of what was identified to be on the image and what was really on the ground," said Win.

Researchers can detect vineyards, citrus orchards, oaks, eucalyptus, avocados, cacti and ornamental vegetation, as well as riverbanks, ditches and pond shores where the pest may live. Scientists can put bright colors on the digital maps to clearly show different kinds of plants by using different colors for different species.

The pilot project took place from March until October this year. There are about 46,000 acres of vineyards in the Salinas Valley that generate about a half-billion-dollar grape-wine economy.

"The pilot area covers approximately 15 percent of the Salinas Valley and 10 percent of the total vineyard acreage in the Salinas Valley," Win said. "Mapping county-wide vineyards and other potential glassy-winged sharpshooter habitats is being considered for the next phase."

BASIC sponsored the sharpshooter work with funding from the NASA Earth Science Enterprise. BASIC worked with the CSUMB-SIVA Center to carry out the project in collaboration with the Monterey County Agriculture Commissioner's Office.

More information about the sharpshooter pest is on the Internet at:

http://plant.cdfa.ca.gov/gwss and at: http://www.basic.org

##

Contact:
John Bluck
NASA Ames Research Center, Moffett Field, Calif.
650-604-5026 or 604-9000
jbluck@mail.arc.nasa.gov

Recommend this Article to a Friend

Back to: News