Fruit fly invasion puts 79 square miles of Los Angeles County under quarantine

It is believed the fruit fly, native to Asia, was introduced to California by travellers with uninspected fruit

A 79-square-mile section of Los Angeles County has been placed under quarantine after an invasive fruit fly known as Tau was discovered in Stevenson Ranch, the California Department of Food and Agriculture  (CDFA) said.

Last week, the CDFA placed a quarantine after more than 20 Tau fruit flies (Zeugodacus tau group) were detected in the unincorporated area of Stevenson Ranch near Santa Clarita.

Tau fruit flies, which are native to Asia, are “a serious pest for agriculture and natural resources” as they have a wide-hosting range for various vegetation native to California.

Residents living in the quarantined area have been urged not to move any fruits or vegetables from their property to prevent the invasive species from spreading.

The CDFA said that residents may consume or process fruits and vegetables from the property they are picked at but otherwise should be disposed of via double-bagging in plastic and placing them in garbage bins.

This quarantine is the first time there has been a Tau fruit fly quarantine in the Western Hemisphere.

It is believed that the Tau flies were introduced to California by travellers bringing uninspected produce into the state.

The CDFA said this is a common pathway for invasive species.

The Tau fruit fly quarantine boundary map (CDFA )

It is able to host at least 34 types of fruits and vegetables in nine different plant families including melon, okra, peppers, papayas, citrus, cucumber, pumpkin, tomato, avocado and gourds.

An adult female can lay eggs in fruits or vegetables causing larvae to feed on them and result in decay

The CDFA said it was working with the US Department of Agriculture and the Los Angeles County Agricultural Commission to eliminate the fruit fly from the area and prevent it from spreading.

Some of these tactics include cutting host fruits and vegetables to inspect for fruit fly larvae, treating large properties with organic-approved material, implementing fly traps and treating areas with a small amount of pesticide.