Issue 2, May 1, 2009
Scouting Watch
In southern Illinois, as common lilac, Syringa vulgaris, finishes bloom, it is time to treat for lilac or ash borer, scurfy scale, and the brown race (apple race) of oystershell scale. Look for the pupal cases of the lilac or ash borer protruding from one-quarter inch diameter round holes in the trunk. Scurfy scale crawlers are purplish-red; oystershell scale produces gray crawlers which will be easily visible along leaf veins. Throughout the state, be alert for infestations of Eastern tent caterpillar. In central and northern Illinois, treatment of spruce spider mite should still be effective.--Phil Nixon
Author:
Phil Nixon