No. 12/July 20, 2015
Reports of jumping oak plant gall, masker chafer, and fall webworm are discussed.
Japanese beetle adults are present throughout the state. In most areas, numbers are low, but there have been reports of locally high numbers. We continue to see low numbers in east central Illinois from Onarga south to Charleston and west to at least Monticello. This area continues across central Indiana and most of central Ohio. Research studies have discovered no reason for the lower numbers over the past several years.
Fungus-attacked anthomyiid flies are being found on the ends of tree and shrub branches. Anthomyiid flies are gray and look like house flies but are slightly smaller. Many of them are leafminers or root feeders in the larval stage, and they are not generally considered to be pests of ornamental plants.
Scab and black canker are two diseases of willow (Salix spp.) associated with rapid blighting of leaves and shoots as well as dark brown to black stem cankers. Willow blight is the term used to describe a plant simultaneously infected with both diseases. Willow blight can cause extensive defoliation and dieback to susceptible hosts.
Bacterial Leaf Scorch: The Time to Test Is Now!
Bacterial Leaf Scorch (BLS) is a serious infectious disease with a wide host range of trees and shrubs. The disease causes the slow decline of the host, resulting in host death. It is caused by the bacterium Xylella fastidiosa which is also responsible for Pierce's Disease in grapes and is currently causing widespread damage to the Italian olive industry.