What is Happening? An exotic insect pest is a species that is not native to California, is not established here, and could be harmful.  Different exotic insect pests may be harmful to different things, including one or more of the following: fruits, vegetables, other plants, stored food, native animal species, structures, and human beings. Please note that this is why bringing fruits, vegetables, or plant materials into California without official inspection can be illegal.
	White Striped Fruit Fly Specimen Photo provided by Dr. Jason Leathers, California Department of Food and Agriculture

The White Striped Fruit Fly is an exotic insect pest that poses a threat to fruits, vegetables, and other plants.  Until July 9, 2009, this species had never before been officially documented in the Western Hemisphere.

As of this update, eight specimens have been found in Los Angeles County, all in or around La Verne, San Dimas, and Pomona.  The most recent find was on July 22.

About This Pest

This species is normally found on Christmas Island (a territory of Australia), the Andaman and Nicobar Islands (India), Indonesia (Java, Lombok, Sulawesi, Sumatra), peninsular Malaysia, and southern Thailand.  It is known to attack guava, mango, carambola, tropical almond, Singapore almond, jackfruit, clove, watery rose-apple, rose apple, Malay-apple, water apple, and a number of Asian trees occasionally planted as ornamentals.  The species may attack additional fruits, vegetables, and plants, although this hasn’t been documented yet, possibly because the White Striped Fruit Fly hasn’t had the opportunity to encounter them.

The damage occurs after the female lays eggs in the fruit.  These eggs hatch into larvae, or maggots, which tunnel through the flesh of the fruit.  Decay organisms enter the fruit, leaving the interior of the fruit a rotten mass, making it unfit for consumption.  Because of this, the White Striped Fruit Fly is a threat to home-grown fruits and vegetables, and professional agriculture.

What is Being Done to Fight This Pest?

The California Department of Food and Agriculture is currently working to eradicate this infestation of White Striped Fruit Fly with four different actions:

1) Eradication traps, otherwise known as bait stations.  A thousand traps per square mile have been placed over a fifteen square-mile area.  These traps use a small mixture of cuelure and naled to lure and kill male fruit flies.  The traps are placed in or on trees, shrubs, or other inanimate objects.  California has used this same approach for more than 30 years for exotic fruit flies.

2) Larval surveys/fruit removal.  Larval surveys, or looking for larvae, may be performed up to 200 meters around any property where a specimen was trapped. If larvae are present, fruit from the infested and adjacent properties may be removed for disposal by state personnel.

Residents of affected properties will be notified in writing at least 24 hours prior to removal of the fruit.

3) Ground spraying.  Any property where larvae, a mated female specimen, or evidence of a breeding population is found may be treated by spraying shrubs with a small amount of an organic formulation of spinosad protein bait. Visit the CDFA website to learn more about the treatment process at http://www.cdfa.ca.gov/phpps/videos/spinosad/.

Properties within a 200 meter radius may also be treated.

Residents of affected properties will be notified in writing at least 24 hours prior to treatment.

4) Quarantine. A quarantine restricts the movement of certain fruits, vegetables, and plant materials through the area or out of the area.

How Did This Pest Get Here?

We don’t know for sure.  With modern shipping and travel, exotic pests can get from one side of the planet to the other in mere hours.  Extensive pest exclusion policies and procedures do prevent many potential infestations.  However, whether a pest avoids these safeguards on its own, or hitches a ride with illegally smuggled items - whether the smuggler intended to smuggle or was simply unaware of the law - some do get into Los Angeles County.

We place and monitor thousands of insect pest detection traps all over the county.  When we find an exotic pest, the California Department of Agriculture will place delimitation traps in that area to determine if there is a problem.

What Can I Do to Help?

Do not bring back uninspected fruits, vegetables, or plant material from outside of the state or country.

Discourage friends and family from out of the state or country from sending you these items unless they are can be officially inspected.

If you live in the area under the White Striped Fruit Fly quarantine, do not remove fruits, vegetables, or plant material from the quarantine area.

Report the illegal movement of fruits, vegetables, and plant material.  Report fruit fly maggots (spindle-shaped, cream or white-colored with no visible head or legs.): California Department of Food and Agriculture Exotic Pest Hotline: 1-800-491-1899.

For More Information

Please see the California Department of Food and Agriculture website:
http://www.cdfa.ca.gov/PHPPS/PDEP/treatment/wsff_treatment.html