No. 6/June 1, 2015
Modified Growing Degree Days (Base 50°F, March 1 through May 28)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the links in this article with the degree day accumulations listed to determine what insect pests could be active in their area.
Correct pest identification is the first step in developing a successful Integrated Pest Management (IPM) plan. Sadly, not every pest is easily identified, especially when you start talking about all the biotic/non-pathogenic problems such as chemical drift, drought, lightning, soil compaction, etc., coupled with the true bugs, fungi and weeds.
Rose Rosette Virus
Rose rosette disease was first described in the early 1940s in North America. In the seven decades since, rose rosette has become established across the Midwest and is now found across most of the United States. The causal agent of the disease, a virus, was isolated and identified in 2001. This virus was named Rose Rosette Virus, or RRV.
Hosta Virus X
Take a tour of any shade garden, especially mine, and you will likely find an extensive collection of hostas. Hostas are one of the most popular herbaceous ornamentals; available in seemingly endless varieties of colors, patterns, sizes, and leaf shapes. Though considered mostly problem free, hostas are hosts to a number of potential pests. Hosta Virus X (HVX) continues to be one of the most important hosta diseases.
Although numerous insects feed on milkweeds, most of them do not seriously damage the plants and are also colorful additions to the landscape. Exceptions to this are two drab weevil species that cause serious dieback of the plants and reduce seed production.
Viburnum Leaf Beetle
Obvious damage by viburnum leaf beetle is being found in northern Illinois. This is an exotic, invasive species common in areas of the northeastern U.S. that has recently been found in Illinois.
Gypsy moth caterpillars are fully grown in northern Illinois and are migrating to pupation sites. They are up to two inches long, dark, and hairy with pairs of blue and red balls in rows down their backs. Mature caterpillars climb down from infested trees and migrate, looking for a place to pupate. They locate a crack or crevice and pupate there, emerging as moths later in June to mate and lay eggs that overwinter.