In addition, the well-established nucleopolyhedrosis virus of the gypsy moth also took its toll. Hatch of gypsy moth caterpillars was noted April 16 at 100 Growing Degree Days this year - right on schedule. Based on how this fungus disease has behaved in other locations in the United States, our cool, wet spring should help the fungus keep gypsy moth populations to very low levels again in 1999. Delaware Department of Agriculture will continue to monitor conditions in Delaware in a coordinated effort with the USDA Forest Service and neighboring states to determine the impact of this fungus disease. Last Thursday, April 29, crabapple scab was first seen on susceptible crabapple cultivars in Newark.
Early symptoms are an olive drab or brownish discoloration of the leaves.
Symptoms can vary depending on cultivar. If control is needed, don't delay applying a fungicide now and 10-14 days later. Our native sycamores, Platanus occidentalis , have taken a beating the last two years from sycamore anthracnose. This year may be different. This fungus disease may not have been as favored because of the cool, windy weather.