A 79 square mile (204.5 km) swath of territory in Los Angeles County has been put under quarantine in an attempt to halt the spread of a Tau, an invasive species of fruit fly native to South and Southeast Asia.
California’s Department of Food and Agriculture (CDFA) announced the quarantine after over 20 Tau flies - whose adult specimens grow to up to 7 mm in length, were discovered in the community of Stevenson Ranch, about 55 km from Los Angeles, last week.
The CDFA characterizes the winged insects as a “serious pest for agriculture and natural resources,” with the flies said to pose a threat to some local plant life, as well as crops like avocados, citrus fruits, peppers, tomatoes, and cucurbit crops, which the bugs like to munch on.
Residents in the quarantine area are prohibited from removing any fruits and veggies from their homes, and are ordered to throw them away in double-bagged trash bags to prevent the flies from spreading. However, any fruits and veg picked on homeowners’ property can still be processed or consumed.
CDFA containment officers have been deployed to the quarantine zone to areas where the flies have been spotted to inspect crops for Tau larvae, spray the area with Spinosad, an insecticide, and attempt to trap the flies using pheromone lures.
Tau fruit flies, which made an appearance in San Bernardino County, California in 2016 and have been spotted three times since, are thought to have been brought into the US by unsuspecting travelers carrying produce containing their larvae.
Tau fruit flies are distinguishable by their unique yellow/black color, and have clear wings marked with dark strips. Their cylindrical, white eggs grow to up to 1 mm long, and females lay them in fruit and vegetables, which larvae then feast on as they tunnel through.
The species is native to countries across much of Asia, including China, India, Vietnam, Cambodia, Laos, Thailand, Malaysia, Singapore, Brunei, Indonesia, Bangladesh, Bhutan, and Sri Lanka. In their home climes, they are deemed a major pest of cucurbit crops like pumpkin, cucumber, squash, gourd, and watermelon.