For more information, e-mail
us or call (509) 249-6966.
Apple Maggot Facts
Why the apple maggot is a significant threat to fruit crops
Directly attacks fruit, making it brown, mushy, and inedible.
Key fruit attacked are apples, crabapples, cherry, pears, plums,
and apricots.
If left unchecked, would have devastating impact on the apple
industry, the number one cash crop in Washington.
History of the apple maggot in Washington
First detected in 1980 in Clark County.
Soon spread up the Interstate 5 corridor.
Now present in 22 of Washington's 39 counties. This includes: 17
western Washington counties (Clallam, Clark, Cowlitz, Grays Harbor,
Island, Jefferson, King, Kitsap, Lewis, Mason, Pacific, Pierce,
Skagit, Snohomish, Thurston, Wahkiakum, and Whatcom), two counties
in the Columbia Gorge (Skamania and Klickitat) and three counties
in eastern Washington (Kittitas, Spokane, and Yakima).
How the apple maggot is spread
Mostly by people transporting apples from infested backyard apple
trees to non-infested areas of the state.
Some spread due to abandoned orchards.
Some spread also due to natural spread -- a very slow process.
WSDA’s apple maggot control program
Established in 1980.
Administered in concert with the Apple Maggot Working Group,
made up of representatives from Washington State Dept. of Agriculture
(WSDA), Washington apple industry, tree fruit research community,
and the federal government.
Consists of three components: A survey and regulatory component
administered by WSDA; a control, suppression and eradication component
administered by county pest boards; and an education component
conducted by Washington State University through its cooperative
extension offices.
Apple maggot trapping program conducted annually. Between 5,000
and 8,500 apple maggot traps placed in field each summer. Field
activities determined by WSDA and Apple Maggot Working Group.
Trapping results forwarded to county pest boards for control,
suppression, or eradication actions they consider appropriate.
Counties may be quarantined in whole or in part based on trap
catches and other evidence of apple maggot activity detected.
Purpose of apple maggot quarantine
Facilitate the movement of commercial fruit to domestic and international
markets by providing shippers with one of two types of WSDA documents
certifying their fruit is apple-maggot free.
One certificate states no apple maggot flies were caught within
a half-mile of the orchard shipping the fruit. The other certificate
states flies were caught within a half-mile of the orchard, but
WSDA inspection revealed no apple maggot larvae in the fruit.
Success of apple maggot control program
Apple maggots have never been found in commercially packed fruit
in the state.
Additional sources of data
Apple maggot control program: Dr.
Brad White, WSDA pest program manager, telephone (360)
902-2071.
Apple Maggot Working Group: Dr. Mike Willett, current chairman,
telephone (509) 453-3193. Dr. Willett is Vice-President for Scientific
Affairs, Northwest
Horticultural Council.