The invasive pest spotlight focuses on emerging or potential invasive pests in California. In this issue we are covering the Mediterranean fruit fly.

Mediterranean Fruit Fly Facts

Mediterranean fruit fly adult. Photo by Jack Kelly Clark.

The Mediterranean fruit fly, Ceratitis capitata, commonly called Medfly, attacks more than 260 different plant species. It can be especially damaging to mango, citrus, grapes, and stone fruits. The Medfly originated in Africa and has spread around the world, becoming one of the most destructive agricultural pests. Despite recent successful eradication efforts in California, Mediterranean fruit fly was detected in Alameda County and prompted a quarantine in September 2024.

The adult Medfly is about 1/4 inch long, and very colorful. Its body is blackish with silver markings on the thorax, and its tan abdomen has dark stripes. The wings are clear with light brown bands and gray spots near the base. The white eggs are tiny and hatch into legless white larvae called maggots.

Under ideal conditions, the Mediterranean fruit fly can complete its life cycle in just 21 days. The eggs are laid under the skin of vulnerable fruits and hatch within a few days. The maggots feed upon the pulp of host fruits, tunneling through and reducing the whole to a juicy, inedible mass.

What can you do?

If you are located within a quarantine area, you can help prevent the spread of invasive fruit flies:

• Do not move any fruits or vegetables from the property. Consume or process (juice, cook, freeze) fruits and vegetables on site.
• Dispose of any fallen or unwanted fruit or vegetables by double bagging in plastic bags and placing in the garbage bin, not green waste.
• Cooperate with agriculture officials and allow them access to inspect plants.
• Report suspicious pests and maggots inside of your fruit to your local county agricultural commissioner's office or to CDFA's Pest Hotline at 1-800-491-1899.

Smuggled and illegally imported fruit is the most common pathway of invasive fruit fly entry into California. To help protect California's agriculture and natural resources, review the Don't Pack a Pest guidelines at https://www.dontpackapest.com/.