No. 10/June 26, 2009

The emergence of bagworms appears to be a mixed bag this year. There are very high populations that have hatched and settled down to feed in southern Illinois.

Japanese Beetles
Japanese beetle adults have emerged throughout southern and central Illinois. They were reported "balling" on turf in Urbana on June 22.

Wet Weather Turf Pests
The heavy rainfall this spring has resulted in higher numbers of some insects and insect relatives than normal. These conditions are also conducive to high numbers of millipedes, fungus gnats, slugs, and earwigs.

Cercospora Blight of Juniper
Cercospora blight of juniper is not usually a big problem in Illinois. It is more common in areas where Rocky Mountain juniper (Juniperus scopulorum) is grown. This year, however, we have seen this disease.

Wetwood and Slime Flux
It is likely that increased incidents of slime flux now have to do with increased sap flow of trees in the spring and early summer.

Black Knot
The fungal disease, Black Knot (Apiosporina morbosa), affects about 25 Prunus species. The more susceptible species include edible and ornamental plums and cherries.

Canada Thistle Management in Lawns and Landscapes
Canada thistle (Cirsium arvense) is a noxious (and obnoxious) weed that I occasionally get questions about. This plant is listed in 43 states' noxious weed laws meaning that its control is required by law. Illinois is no exception.