Guava fruit flies should not affect South County growers, ag commissioner says

An immediate emergency eradication program initiated Wednesday, after three male guava fruit flies were found in traps in San Jose’s Mayfair neighborhood two weeks ago.
“We have traps out all over the county at all times so that we can notice right away if anything comes in,” Santa Clara County Agricultural Commissioner Joe Deviney said. “We caught the three flies in Mayfair very early.”
The eradication involved the spreading of a deadly insecticide on trees and telephone poles in the area by state and county crews. The insecticide will attract only male fruit flies which are being targeted in order to stop production of larvae with females. Larvae become maggots which pose a threat because they crawl into the fruits they like, such as guavas, peaches, cherries, citrus and melons, and make the crops inedible.
“The maggots burrow inside the fruit, which the person then throws out because they can’t eat it, and then they lay eggs and populate,” Deviney said.
The guava, an exotic fly from Southeast Asia, is in the same genus as the Oriental fruit fly which posed a threat to Morgan Hill and was eradicated in April. The theorized explanation for how guava fruit flies have appeared in the Santa Clara County from another continent is similar to that of the Oriental fruit fly.
“We think they come from contraband fruit that someone brings back on a plane,” Deviney said. “I mean, they obviously can’t fly here.”
Fortunately for local farmers, the guava flies are currently in a mostly urban area and the likelihood is high that they going to stay contained there according to Deviney.
“The guava flies are not affecting any growers in San Jose or anywhere else in the county at this time,” Deviney said.