San Diego County and the California Department of Food and Agriculture have expanded a quarantine zone after the Mexican fruit fly was detected outside its original area, raising concern for commercial agriculture and backyard fruit trees.
Officials say the invasive pest can cause serious damage if it spreads further.
“The Mexican fruit fly is a very serious agricultural pest. It is invasive. When it is detected, there is a very serious response that we take,” said Garrett Cooper, assistant commissioner of agriculture, weights and measurements for San Diego County.
County officials say the pest is dangerous to both farms and home gardens because it lays eggs inside fruit, where the larvae then develop and make the fruit unusable.
“It can be a very damaging pest to agriculture and fruit trees at residences,” Cooper said.
Quarantine zone now includes several communities
The county says it has more than 6,000 traps deployed across San Diego as part of its monitoring effort. A team in La Mesa showed where the fly was found, prompting the expanded response.
The current quarantine area includes La Mesa, Spring Valley, and El Cajon, covering about 111 square miles, officials said. Residents in those areas are being asked not to move fruit or vegetables out of the quarantine zone.
How officials are fighting the pest
If a tree is suspected of being infected, state and county crews will remove and dispose of all fruit from the tree to help stop the spread. Other control methods include spraying an organic substance called Spinosad and releasing sterile male flies that mate with females, preventing the pests from reproducing.
“Male fruit flies that are sterile, and they will meet with the females and that ends the reproductive cycle,” officials said.
What residents should do
Homeowners in the quarantine area are being urged to pay close attention to door hangtags left by county crews and to follow all instructions. Officials stress that residents should not move homegrown fruit or vegetables out of the neighborhood, since doing so could spread the pest further.
The county says anyone who suspects there is an infected tree should contact the California Department of Food and Agriculture.