Effective Insect & Disease Control Tips for Summer and Early Fall

Protect Your Trees with Expert Advice from Tree Care Enterprises

Warm summer days and crisp early fall evenings are beautiful in Northern Illinois—but they’re also peak seasons for many tree pests and diseases. If left untreated, these problems can cause lasting damage to your trees, reducing their health, beauty, and safety.

At Tree Care Enterprises, we’ve been helping homeowners and property managers protect their trees from pests and disease for over 45 years. Here’s what you should know to keep your trees thriving during the most active months for insect and disease activity.

Common Tree Pests in Summer and Early Fall

Insects feed on leaves, bark, or roots, often weakening the tree and making it more susceptible to disease. Keep an eye out for these common pests in Northern Illinois and Southern Wisconsin:

• Emerald Ash Borer (EAB) – Metallic green beetle that attacks and kills ash trees.
  
  
• Japanese Beetles – Feed on foliage, leaving behind skeletonized leaves.
  
  
• Aphids – Tiny, sap-sucking insects that cause leaf curling and sticky honeydew residue.
  
  
• Scale Insects – Small, immobile pests that attach to branches and suck plant juices.
  
  
• Bagworms & Caterpillars – Defoliate trees quickly if left uncontrolled.
  
  

Common Tree Diseases in Our Area

Summer and early fall also create ideal conditions for certain fungal and bacterial diseases:

• Anthracnose – Causes brown spots and curling on leaves.
  
  
• Apple Scab – Affects ornamental and fruiting apple trees, creating dark lesions.
  
  
• Powdery Mildew – White, powder-like coating on leaves.
  
  
• Verticillium Wilt – Soil-borne fungus that blocks water flow in the tree.
  
  
• Fire Blight – Bacterial disease causing blackened, scorched-looking leaves and shoots.
  
  

Effective Tips for Controlling Insects and Disease

1. Inspect Your Trees Regularly

Catch problems early by checking your trees throughout the growing season. Look for:

• Chewed or discolored leaves
  
  
• Unusual growths or swellings
  
  
• Sticky residue on leaves or patio furniture
  
  
• Dead or thinning branches
  
  

2. Water and Mulch Properly

Healthy trees are more resistant to pests and diseases. Deep watering during dry spells and a 2–4 inch mulch layer help reduce stress and improve resilience.

3. Prune Wisely

Remove dead, diseased, or infested branches promptly—but avoid heavy pruning during peak pest season. Proper pruning improves airflow, which reduces fungal growth.

4. Use Targeted Treatments

Insecticides and fungicides should be applied at the right time and in the correct manner to be effective. Our certified arborists can determine which treatments are needed—and when.

How Tree Care Enterprises Can Help

Our Insect & Disease Control Program is designed to protect your trees from summer through fall. We offer:

• Certified Arborist Inspections to identify pests and diseases early
  
  
• Customized Treatment Plans using environmentally responsible products
  
  
• Preventive Care to keep healthy trees pest- and disease-resistant
  
  
• Follow-Up Monitoring to ensure the issue is under control
  
  

Protect Your Trees Before Problems Spread

Insects and diseases can move quickly—especially during warm, humid months. Don’t wait until the damage is severe. Contact Tree Care Enterprises today for a professional evaluation and treatment plan.