Exotic Fruit Fly Quarantines in California
Introduction
Federal and state quarantines protect against the entry and spread of exotic fruit flies by requiring strict adherence to treatment and inspection procedures for hosts. Smuggled and/or illegally imported fruit is the most common pathway of fruit fly entry into California.
The California Department of Food and Agriculture (CDFA), in concert with most of the County Agricultural Commissioners, deploy and maintain over 63,000 detection traps statewide just for exotic fruit flies.
The fruit flies (family Tephritidae) of most concern are a group of small (1/5" to 1/3") to medium-sized (3/4") flies, with general body coloration that can be in the red, orange, yellow or black ranges. Their wings generally have brownish streaks and may also display scattered dark spots. There are four life stages: adult; egg; larva; pupa (puparium).
The eggs of these flies are slender, white and have an elliptical shape, and are typically laid in batches of 3 to 40, under the skin of the host fruit. The larvae (the maggots in the fruit) are cylindrical in shape, approximately ½" long and creamy white in appearance. The contents of their guts are often visible through their skin, and large numbers can colonize the flesh of individual host fruits. Some species will attack flowers and plant stems as well. The puparium (pupa case) can be colored either dull white, dark brown or black. It is just over an inch long and usually found in the soil from 2" to (rarely) 6" deep.