No. 1/April 16, 2012

First Issue of 2012
Welcome to the Home, Yard, and Garden Pest Newsletter. Our purpose is to provide disease, insect, weed, and other pest information on a timely basis for the professionally-maintained landscape. We write primarily for arborists, landscapers, lawn care professionals, golf course superintendents, and garden center operators.

Weather Impacts on Insects
This has been an unusual weather year, and there have been numerous concerns about its effect on insects. Although the winter was mild, the warmer temperatures had little effect on insect survival or spring emergence.

Scouting Watch
Eastern tent caterpillar, European pine sawfly, and gypsy moth are discussed, as well as information about scouting during the spring months.

2012 Season at the University of Illinois Plant Clinic
What a fantastic start to the 2012 season! Samples have already been arriving this spring here at the Clinic in our 37th year of operation. The unusually warm weather has inspired early yard work and observations of pest issues in home and commercial landscapes. The University of Illinois Plant Clinic began year-round operation in the fall of 2011, when we moved from our facility on St. Mary’s Road to our new location in Turner Hall on the south end of the Urbana campus.

Widespread Frost Injury to Trees and Woody Ornamental Leaves
The freezing night temperatures this past week took a toll on the leaves of woody ornamentals and tree that were still in the early process of leafing out. Frost injury occurs when ice crystals form within the plant cells and rupture the cells. This produces a water soaked appearance to the tissue.

Can Drought Stress of Tree and Shrubs = More Disease (and Other Problems)?
During the summer of 2011, large portions Illinois were subject to drought and below average precipitation. Central portions of the state were especially dry. During a drought, plants grown in landscapes often suffer stress due to an inadequate supply of available water. To alleviate this stress, homeowners often turn to the garden hoses and sprinklers. Unfortunately, we often focus our watering turf and herbaceous plants while neglecting trees and shrubs.

Do You Recommend a One-Time Fungicide Injection Treatment for Apple Scab?
The apple scab fungus infects under a wide range of temperatures but requires a wetting period to become established on a tree. Usually, Midwestern weather in the spring provides just what the scab fungus needs. The minimum wetting period on the leaves is only about 6 hours if temperatures stay near the optimal 60 degrees F. If temperatures are cooler, the wetting period must be longer for infection to occur.