Take a stroll through Orange County neighborhoods and you’re likely to see street light poles with a mysterious black substance.
The first recorded Southern California oriental fruit fly (OFF) detections were in 1960. California Department of Food and Agriculture (CFDA) officials have detected the invasive species in several Orange County cities over the intervening years, prompting treatment measures to eliminate the pests’ threat to California’s environment, agriculture and economy.
OFFs are known to attack over 230 types of at-risk fruits and vegetables such as pome and stone fruits, citrus, dates, avocados, tomatoes and peppers by laying eggs that hatch into larvae and feed on the produce, making it unfit for consumption.
In a collaborative eradication effort in 2022, the CFDA and USDA’s Animal and Plant Health Inspection Service eradicated the OFF population through various control methods.
One of these was the male attractant technique (MAT), which uses a solution of methyl eugenol and pesticide that’s mixed into a waxy time-release matrix to lure and kill male flies. MAT was applied to street light poles in the cities of Garden Grove, Santa Ana and parts of Huntington Beach and Fountain Valley.
If evidence that a breeding popu-lation exists on a property, all host fruit is removed from properties within a minimum of a 100-meter radius around the detection sites and taken to a landfill for burial using regulatory compliance protocols. A quarantine is then placed on the surrounding areas until the pest is eradicated.
The most recent quarantine for Fountain Valley & Huntington Beach was lifted in 2023 after three generations of the fly had passed without further detections. While the quarantine has ended, OFF infestations are an ongoing concern in California. Bringing fruit and vegetables into the state from other counties/countries increases the chances of OFFs travelling with you.
“Residents can help protect California from invasive fruit flies by not packing a pest,” said Jason W. Leathers, branch chief and environmental program manager who oversees the Pest Detection and Emergency Projects at the CDFA.
Instead, residents should buy fruits and vegetables locally and refrain from buying it through social media, sold outside of regulated channels could be infested with invasive fruit flies, he added.