No. 4/May 20, 2013

Scouting Watch
Bridalwreath spirea is now blooming throughout the state.

Emerald Ash Borer
Emerald ash borer continues to spread through the state. During the last year, it was first found in the Dixon, Galesburg, Kewanee, and Ogle County areas in north central and northwest Illinois. These were expected with the infestation in nearby Peru found in 2007. Similarly, infestations in Champaign and Livingston County are near established infestations.

Ticks are more numerous this year than usual. Probably, the frequent spring rains in much of the state have provided the high moisture and subsequent humidity that ticks need. Ticks are large, flattened mites that feed as parasites on mammals, birds, and reptiles.

Registered Herbicides Recommended Over Non-Conventional Weed Killing Mixes Touted Online
There are many reasons why do-it-yourself weed killers are so popular.  As with anything though, you often get what you pay for. 

Basil Downy Mildew
The U of I Plant Clinic recently diagnosed a basil sample with downy mildew. Dr. Mohammad Babadoost, University of Illinois Extension plant pathologist, reported that growers had first found downy mildew in Illinois on commercial basil crops in 2009.  This disease can be very aggressive and can easily spread via wind-dispersed spores.

Modified Growing Degree Days (Base 50°F,  March 1 through May 16)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity.  In warm years, insects emerge earlier, like we experienced last spring. Degree day accumulations remain slightly behind, but high temperatures this last week have begun to get us closer to being on track with the historical average.

Know Your Invasives: Learn to Identify Locally Invasive Plants
During a time of year when gardens are being planted, crops are being cultivated, and yards are being adorned with flowers, it is ever so important to be able to recognize what plants are invasive.

Ash Anthracnose
This spring has presented us with extended periods of cool, wet weather. These conditions, when present during leaf expansion, often result in outbreaks of anthracnose. However, the plant clinic has received only a few reports of anthracnose occurring within the state. In fact, I received my first anthracnose (on ash) email of the year, earlier this week.