Forest Health

Adult Emerald Ash Borer

Adult Emerald Ash Borer (James E. Appleby, University of Illinois)

The State of Illinois is actively committed to fostering healthy, vigorous, high quality forests for the greatest good of society and the environment. Nevertheless, our trees and forest ecosystems are susceptible to a variety of native and exotic pests and pathogens, in addition to the seemingly more benign, but just as damaging effects of time, weather, and anthropogenic disturbances.

Illinois’ most notable biological forest health concerns range from insects including the emerald ash borer, gypsy moth, and Asian longhorned beetle; to pathogens such as oak wilt, ash-yellows, and miscellaneous wilts, cankers, and rots; to invasive and exotic species such as Eurasian honeysuckle, garlic mustard, and autumn olive. Additional forest health concerns that generally precede insect and disease events and often trigger general tree decline and mortality include over-stocked forest stands; senescent forest stands; flooding, draught, and storm damage; and anthropogenic disturbances such as herbicide drift and nutrient/pesticide runoff; ozone and acid rain; mechanical damage and soil compaction; and increased sedimentation, erosion, and altered hydrology from agricultural practices and general construction.

Shade Tree Advice

For community and private shade tree advice and assistance, please contact a certified arborist, city forester, Master Gardener, or your local Extension office. For technical assistance concerning prevention, detection, evaluation, and control measures for insect and disease outbreaks in your forest, please contact your local DNR forester.

Tissue or insect samples may be hand-delivered or mailed to the University of Illinois Plant Clinic in order to assist citizens and tree care specialists diagnose tree decline or identify damaging insects. Please refer to the Plant Clinic’s website for tissue and insect sample submission guidelines and fees.

Forest Health Newsletters

Emerald Ash Borer

Asian Longhorned Beetle

Sudden Oak Death

Identification & Treatment

Invasive Species

USDA Forest Service Links

Additional Contacts

University of Illinois Plant Clinic
1401 W. St. Mary’s Street
Urbana, IL 61802
Ph: (217)333-0519

James E. Appleby, Ph.D.
Research Associate Professor of Forest Entomology
S517 Turner Hall, (MC047)
1102 South Goodwin Avenue
Urbana, Illinois 61801

Philip L. Nixon, Ph.D.
Extension Entomologist
S408 Turner Hall, (MC047)
1102 South Goodwin Ave.
Urbana, Illinois 61801



U of I ACES U of I Extension