Western cherry fruit fly expected to emerge Sunday

Written by Observer Upload June 08, 2012 12:48 pm

The Union County Cherry Fruit Fly Inspector Greg Franklin has announced that emergence of the first adult Western cherry fruit flies will begin Sunday in the 
La Grande area. 

Initial spray applications should be made within the first week after emergence and then follow-up spray applications should be scheduled to control the insects until harvest. One spray application does not provide season-long cherry fruit fly control.

Management options for the Western cherry fruit fly include:

1) Spray your own trees with registered insecticide products. OR

2) Hire a commercial applicator to spray trees. Currently, Ridley Pest Control (541-910-7378) is the only known commercial pesticide operator (CPO) in Union county available for cherry fruit fly control. Other licensed CPOs (through the Oregon Department of Agriculture) are encouraged to contact the Union County OSU Extension office to be included on the service provider list. OR

3) Remove all blossoms or fruit from trees prior to cherry fruit fly emergence. OR

4) Cut trees down. Unmanaged fruit trees do not make good shade trees because they harbor a variety of insect and disease pests. lt is recommended to remove any cherry trees not used for fruit production and replace with a suitable shade tree. Franklin will cut unwanted cherry trees down at no cost. However, the wood will be left on site. Call Franklin at 541-663-3345.

Tree height and canopy influence effectiveness of sprays. Shorter trees pruned to open up the canopy allows for more effective spray coverage. For further information on cherry fruit fly management and products for control, call the Union County Extension Office at 541-963-1010 or refer to the following references, which are available at the Extension office or at http://extension.oregonstate.edu/index.php.

• 2012 PNW Insect Pest Mgmt. Handbook ($50)

• EC 631 Managing Diseases and Insects in Home Orchards.

Those who choose to spray their own trees are reminded to make sure the product they use is for fruit/cherry trees. It is important to always read and follow label directions for safe pesticide use, frequency of application and pre-harvest intervals!

Western Cherry Fruit Fly Biology Notes: Cherry fruit flies spend about 10 months out of the year as pupae in the soil. For the first week after emergence, adults feed on any available sweet substances and moisture. 

Adults begin laying eggs in fruit seven days after emergence. Adult emergence continues for up to two months. Eggs hatch within seven to 70 days then larvae feed in the fruit for two to three weeks. 

Larvae then emerge from the fruit, drop to the ground and pupate in the soil and overwinter until this time next year. 

Visit the OSU Integrated Plant Protection Center at http://uspest.org/cgi-bin/ddmodel.pl to use the online phenology model.