Los Angeles neighborhoods under 'first-ever' quarantine after invasive Tau fruit fly was detected, raising fears pests native to Asia could destroy avocados and tomatoes

A 79-square-mile area of Los Angeles County has been put under a quarantine after 20 invasive fruit flies from China were detected in one neighborhood.

Tau fruit flies are indigenous to Asia and pose a 'significant threat' to various wildlife including agricultural fruits, vegetables and some Californian plants.

Within the quarantine area, the movement of fruits and vegetables is prohibited but people can travel freely. While the fruit and veg cannot be moved, people are allowed to dispose of them and eat them.

It's believed the fly was introduced to the area by travelers bringing uninspected produce into the state, the agency said.

Although the flies have been detected in the US before - first in 2016 - this is the first time their detection has triggered a quarantine in the Western hemisphere, according to the California Department of Food and Agriculture.

Aerial of suburban Stevenson Ranch community of Los Angeles County where 20 Tau fruit flies were detected, according to the California Department of Agriculture

Tau fruit flies are indigenous to Asia and pose a 'significant threat' to various wildlife including agricultural plants, vegetables and some Californian plants. They are around the same size as a horsefly

The insects were detected in the Stevenson Ranch neighborhood near the city of Santa Clarita,  around 30 miles north of Los Angeles.

They are approximately 7 mm in length - similar to that of a housefly - and feature yellow and black stripes.

The flies are especially likely to be found on cucurbits, avocados, citrus fruits, tomatoes, and peppers, on which female flies lay larvae that then tunnel into the fruit.

A single female can lay more than 400 eggs in her lifetime, according to the Department of Agriculture.

'The fly is native to Asia and is a serious pest for agriculture and natural resources, with a very wide host range, including numerous fruits and vegetables as well as a select range of native plants in California,' said the department in a release.

The quarantine prevents the transport of produce in a 79-square-mile area around the city of Santa Clarita, around 30 miles north of Los Angeles

According to the California Department of Agriculture, this is the first-ever quarantine caused by the Tau fruit fly in the Western hemisphere. Pictured is an aerial view of Stevenson Ranch

'To prevent the spread of this invasive species, residents living in the quarantine area are urged not to move any fruits and vegetables from their property. They may be consumed or processed,' it added.

The agency plans to work with the US Department of Agriculture and local authorities to eliminate the Tau fruit fly and prevent its spread.

That will involve having crews cut host fruit and vegetables on properties within 200 meters of initial detections to inspect for larvae, the state agricultural agency said.

It was advised that any fruit or vegetables that are thrown away should be double-bagged and placed only in garbage bins. Materials should not be placed in green waste.