By Island County Extension Agent, Donald B. Meehan
APPLE MAGGOTS POSE SERIOUS THREAT TO APPLE INDUSTRY
Recent detection of the Apple Maggot pest in the Redmond, Washington area has heightened the concern about the potential damage this particular pest can do to the state's commercial apple industry. Prior to now, the problem has been focused at the southwest corner of the state. Now, we are no longer able to ignore it here in Northwest Washington. The threat comes from the spread of backyard apples and pears throughout the state. Should this pest establish a foothold in the commercial apple orchards, significant economic losses would occur. The biggest worry comes from the multi-million dollar eastside apple and pear industry, but there is a growing apple industry to be found here in Western Washington. It, too, could be threatened.
In 1979, an Apple Maggot was identified from a backyard apple tree in the Portland area. Subsequent surveys indicated this insect was established over 5,000 square miles of the Willamette Valley, including north into Washington State. Since this finding, Apple Maggot-infested apples have been discovered in Skamania, Klickitat, Lewis, Pacific, Cowlitz, Clark and Spokane counties. With the recent discovery in Redmond, the area of contamination seems to be on the rise.
As of July 1st, 1984, the Washington State Dept. of Agriculture imposed a statewide Apple Maggot quarantine (WAC 16-470-100). This quarantine specified that noncomercial apples, crabapples and pears could not be moved within or out of counties where Apple Maggot is known to occur. It has now been extended to all of western Washington. Signs notifying motorists will appear at strategic locations along major highways going north and south, as well as those passing over the mountains into eastern Washington's apple-growing country. In July of 1984, a program was initiated to detect and eradicate Apple Maggots in southwest Washington and the Spokane area. Part of this program was to remove untended and abandoned apple, crabapple and hawthorn trees throughout the areas of infestation. At the beginning of November, 1984, over 100,000 trees and suckers had been removed. This work was done by the Washington Conservation Corps under the supervision of the WSDA.
How can you, as a homeowner, help with this problem? First you can help by learning what to look for so that you can identify Apple Maggot-infested fruit. To my knowledge there have been no discoveries of the Apple Maggot pest in Island County. You can also keep your apples and pears at home and not let others bring backyard fruit to your home.
To identify Apple Maggots at this time of the year one needs to observe the damage done inside apples. This damage appears as irregular brownish tunnels passing throughout the fleshy portion of the apple. The browning becomes more pronounced with time since it is caused by bacterial action after the maggot has passed through. Eventually the fruit becomes soft and rotten. It is generally useless since most of the fleshy portions have been involved.
Should you find an Apple Maggot in the apple or pear it will be no longer than 3/8 inch long and will be cream colored. Codling Moth damage will be different and the larvae will appear whitish to pinkish white with a black or brown head. The Codling Moth larvae will also be longer at maturity reaching up to 3/4 inch in length. The damage it creates inside an apple or pear will be located at the center where the seeds and core area will be consumed.
A publication called APPLE MAGGOT IN WASHINGTON, EB-1227, is available from our office which helps you to identify the maggot at all stages of its development and provides information on controlling the pest. For more specific information about the quarantine that has been imposed, contact the State Dept. of Agriculture in Olympia for the latest revisions to the quarantine.
Return to Articles Index
Return to Garden Page
Providing Educational Support to the Island County Community