No. 7/June 10, 2013

We have been receiving reports of planthoppers and woolly aphids, particularly on ash, in various areas of the state. Both of these insects are covered with and leave behind white, fluffy tufts of waxy strands that get stuck on leaves and stems by the honeydew that these insects excrete. They are unlikely to cause enough damage to warrant control, but can be controlled by the insecticides in the following woolly aphid article.

Woolly Aphids
Adult woolly aphids appear as flying lint, tiny drifting angels, or white fuzzies, close to ¼ inch in diameter, which seem to float through the air. If you try to catch one, you soon realize that it is capable of powered flight. These aphids are green to blue and covered with white waxy strands that stand out from the body.

Common Cedar Rust Disease of Illinois
There are three common rust diseases found in the landscape that use cedar as an alternate host: cedar-apple rust, cedar-hawthorn rust, and cedar-quince rust.

"Keeping Up" with the U of I Plant Clinic
A great way to keep up with the U of I Plant Clinic is to use social media. Access using either Facebook or Twitter for important updates and news, and the latest research on plant problem management.

Common Purslane -- Blessing or Bane?
Common purslane is an interesting plant.  Some will curse its appearance in their garden and others will embrace it.  Again, we are reminded that a weed is only a weed if it is unwanted where it is growing.  The primary redeeming quality to purslane is that it is edible. 

Modified Growing Degree Days (Base 50°F,  March 1 through June 6)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity.

Invasive Species Spotlight: Viburnum Leaf Beetle
Viburnum is one of America's most popular shrubs because of its beautiful flowers and wildlife attracting berries. However, this pretty plant is being threatened by the invasive Viburnum Leaf Beetle, a native of Europe that has been moved to North America on infected viburnums. It is now established in several states in the northeast and has now been found in several Midwestern states.