Presented by John Lough, Senior City Forester April 5, 2017 City of Chicago, Bureau of Forestry Mayor Rahm Emanuel
Types of Tree Problems Insect/Animal Sucking, chewing, boring Disease Fungi, bacteria, viruses Environmental/Cultural Disorders Temperature, drought, flooding, deep planting Common problems often mistaken for insect, animal, or disease damage
Determining the Problem 1. Identify the tree 2. Identify signs & symptoms 3. Examine neighboring plants 4. History if possible 5. Detailed plant examination
Identify Signs & Symptoms
What is a Symptom? Change in the appearance of the plant Response by a plant to a pest or injury General non-specific visual evidence Clues
Common Symptoms Stunted growth Little shoot elongation Small or distorted leaves Leaves Yellowing or browning Damaged Early fall color
What is a Sign? Visible pathogen, such as a fruiting body or discharge associated with the disease OR Visible pest, or any part or product of the pest on the plant Evidence
Insect Signs Non-uniform sucking, chewing, or boring damage Gall formations on leaves Frass Ovipositor scars Eggs Exit holes Insects
Animal Signs Sapsuckers Squirrels Beavers Deer Rodents Rabbits
Disease Signs Mushrooms Vascular streaking Flagging Stem cankers Wilting Oozing sap Destroyed/Injured Fruit or Flowers Gall formations on stem/trunk
Plant Diseases Noninfectious Diseases (Most common type of problem!!)- result of unfavorable growing conditions and not transmitted from tree to tree Environmental stress Cultural stress Infectious Diseases caused by living pathogens, can multiply within the tree and be transmitted between trees Fungus Bacteria Virus
Noninfectious Disease Environmental Problems Lightning Wind or hail Drought String trimmer Girdling roots
Noninfectious Disease Cultural Problems Gas leak Chemical misapplication De-icer Pollution Over irrigation Poor planting Compacted soil
Infectious Diseases Fungus spores spread by rain, wind insects and can actively invade the tree Bacteria single celled and enter through wounds Virus genetic particles transmitted by insects (vectors)
Disease Triangle of Doom Host Environment Causal Agent
How do we manage pest problems?
Plant Health Care - PHC Used to maintain or improve the landscape s appearance, vitality, and safety, using the most cost-effective and environmentally sensitive practices available. Focus on plant wellness Looks at entire ecosystem Long-term prevention of pests or damage
Disease and Insect Prevention Site selection/landscape design light, drainage, fertility Tree selection Proper planting Plant maintenance mulching, watering, pruning Keeping the tree healthy!!!
Insect Problems
Scales Sucking Insect Very small Many shapes Crawling insects Feed on sap Loss of vigor Unsightly Sooty mold Defoliation and die-back of branches
Scales Control Improve growing conditions Natural predators Dormant oil Sprays not as effective since body protected Systemic pesticides may kill beneficial insects
Fall Webworm Chewing Insects Defoliation Reduced vigor Secondary disease/pests Aesthetics
Fall Webworm - Control Prune out tents Natural predators Bacillus thuringiensis var. kurstaki (Bt-k) Promote tree recovery
Gypsy Moth Chewing Insect Spiny caterpillar with blue and red bumps and yellow head 2 3 ½ long Male moth brown with featherlike antennae Female moth white and flightless Egg mass thumb sized and covered with brown buff hair
Gypsy Moth - Damage
Gypsy Moth - Control Bio-controls Insects, pathogens Cultural controls Improve growing conditions Mechanical controls Egg mass removal Chemical controls Mating disruption Trapping Bacillus thuringiensis var. kurstaki (Bt-k)
Japanese Beetle Chewing Insect Creamy white grub with dark head, C shaped with V shaped raster Feeds on roots under the soil Adult beetle 3/8 long Metallic green and copper brown color
Japanese Beetle Control Plant resistant trees Traps?? Mechanical removal Chemical control on turf or on tree Milky spore (Paenibacillus popilliaeno) bacteria no longer effective
Bag Worm Moth Chewing Insect Small caterpillar 1/32 1 ¾ long Spins a protective case with foliage of the host tree Good mobility Attach case to tree to pupate Eggs in case
Bagworm Damage Defoliation Reduced vigor Aesthetic Twig tip mortality Tree mortality most common with evergreens
Bag Worm Control Hand pick casings Natural predators Btk (Bacillus thuringiensis var. kurstaki) Promote tree recovery
Emerald Ash Borer Boring Insect ½ long, 1/8 wide Metallic emerald green with a yellow green abdomen Ash trees only D shaped exit hole Epicormic sprouting
Emerald Ash Borer - Damage Beetle bores in the cambium destroying the nutrient support system Crown decline Tree mortality
Emerald Ash Borer - Control Identify infestation Remove host trees Quarantine -Do not move ash wood Systemic insecticide
Disease Problems
Cedar Hawthorn Rust - Fungus On cedar, reddish galls develop into telia horns On hawthorn, (apple, quince) yellow spots, on leaves, twigs, fruit Two year cycle
Cedar Hawthorn Rust - Control Prune out diseased portion of tree if possible Live with the disease Fungicide application (not very effective) Avoid planting susceptible hawthorns within 2 miles of a juniper (good luck) Plant resistant hawthorns
Black Knot - Fungus Cherry and plum Black swellings on twig/trunk Slowly kills branches Eventual tree mortality Control Prune out affected sections in winter Burn or bury galls Fungicide as a preventative but not cure Promote tree recovery
Thousand Canker Disease - Fungus Black walnut Walnut twig beetle vector Flagging crown, die-back, and beetle holes Black staining on bark
TCD Damage and Control Forms a canker in the phloem Interrupts sap flow and leads to death No known effective control at this time Remove and destroy affected trees
Virus Mosiac virus Insect vectors Not significant on trees
Fire Blight - Bacteria Water soaked spots at wounds, blossoms, and leaves Leaves turn black and shriveled (fire scorched) Shepard s crook Die-back Death
Fire Blight - Control Prune out diseased wood in winter Avoid excessive fertilizer or pruning Remove cankers Plant resistant varieties Streptomycin treatment not very effective
Collecting a Sample Freshly cut/collected Sealed bag Not Wet!! Mail on Monday Include both healthy and diseased tissue Include a detailed description of the problem
Reporting Eyes and ears on the street. Report sightings to: Chicago Bureau of Forestry 312-746-5254 Illinois Department of Agriculture IDOA - 800-641-3934 Resources: Morton Arboretum Plant Clinic - 630-719-2424 Home, Yard & Garden Newsletter - http://hyg.ipm.illinois.edu/
So what s in your trees?