1. WHAT IS GOING ON WITH OUR TREES?
AN UPDATE ON TREE DIEBACK AND DECLINE OR IS IT JUST ANOTHER WAY OF SAYING
“I DO NOT KNOW WHY YOUR TREE IS DYING”

3. THE HOST-STRESS-DECLINE MODEL
Health tree + stress leads to altered trees/tissues and dieback begins
Altered trees/tissues + more stress leads to further dieback
Severely altered trees/tissues + secondary organisms leads to tree/tissue invasion and loss of ability to respond to:
Improved conditions
Decline
Die

4. SYMPTOMS OF DECLINE Slow growth and thin canopy
Twig and branch dieback
Undersized or chlorotic leaves
Adventitious trunk sprouts
Leaf scorch
Premature fall color
“Distress crops”
Acute stress – sudden, and death follows
Chronic stress – long term, ending in tree death or tree stabilizes

5. SUGAR MAPLE DECLINE Affects sugar, red, and Norway maples

6. PRE-DISPOSING FACTORS ASSOCIATED WITH SUGAR MAPLE DECLINE
Herbicide injury drift injury
Restricted rooting space
Saturated soils
Drought
De-icing salts
Soil compaction
Root damage
Insect defoliation
Construction activity

7. SYMPTOMS ASSOCIATED WITH SUGAR MAPLE DECLINE
Thin canopies
Undersized foliage
Leaf color (chlorosis)
Leaf scorch
Early fall color
Branch and twig dieback

8. SIGNS ASSOCIATED WITH SUGAR MAPLE DECLINE
Root rots
Borer exit holes
Girdling roots
Stem and trunk cankers

9. SECONDARY AGENTS ASSOCIATED WITH SUGAR MAPLE DECLINE
Wood-boring insects
(Sugar maple borer/FHATB)
Root rots
(Armillaria mellea)
Stem and branch cankers
(Nectria cinnabarina)
Twig blight
(Steganosporium ovatum)

10. DECLINE OF CONIFERS Weather extremes Poorly drained or droughty soils
Very wet springs and dry summers
Poorly drained or droughty soils
Conifers do not like “wet feet”
Heavy clay soils and poor drainage
Sandy soil dry out quickly
Hot temperatures
Conifers prefer moderate temperatures

11. RHIZOSPHAERA NEEDLE CAST
Hosts: Colorado blue, Norway, and white spruce, pines
Associated with above average precipitation and RH
Signs: yellow bands on needles and dark brown or black fruiting bodies

12. RHIZOSPHAERA NEEDLE CAST
Symptoms: branch dieback, needle drop, thin canopies
Heavily infected needles appear black or purple
Disease starts at base of crown and moves upward and inward

13. CYTOSPORA CANKER Hosts: Norway and Colorado blue spruce
Symptoms: needle browning, lower branch dieback, needle drop, thin canopies
Signs: Cankers on lower sides of branches with amber, purplish white or white resin patches

14. PHOMOPSIS CANKER Hosts: spruce, hemlock, and true firs
Causal agents: Diaporthe eres and D. minospora (more virulent)
Symptoms: sunken-darken areas of stem, cankers, browning of vascular tissue, and canopy dieback

15. PHOMOPSIS CANKER ON SPRUCE
Signs: Pycnidia fruiting bodies resembling small, black pads of tissue erupt and release spores. Resin not always present

16. MANAGING CONIFER DISEASES
Non-chemical management: plant less susceptible conifer species, provide good air circulation, proper spacing, pruning lower branches, and mulching
Sanitation: remove trees in poor condition to prevent future fungal infections and insect infestations
Fungicide treatments (Rhizosphaera) applied on regular basis for first two months after bud break
Fungicide treatments not effective for Cytospora

17. NEW EXOTIC AND INVASIVES PESTS
SPOTTED LANTERNFLY, VIBURNUM LEAF BEETLE, ELONGATE HEMLOCK SCALE, HEMLOCK WOOLY ADELGID

18. SPOTTED LANTERNFLY (SLF)
First discovered in Pennsylvania in 2014 and now in Virginia and Delaware
Potential threat to grapes peaches, apples, and woody plants
Native to China, India, South Korea, and Vietnam

19. SPOTTED LANTERNFLY LIFE CYCLE

20. SIGNS AND SYMPTOMS OF SLF
Susceptible hosts develop weeping wounds leaving greyish or black trail on trunk
Tree of heaven
Walnut
Willow
Late fall, adults lay eggs on host trees, outdoor furniture, vehicles, and structures
New egg masses have grey mud-like covering

21. SPOTTED LANTERNFLY BIOLOGY
Feeding on tree-of-heaven is required for reproduction, but will feed on other plants
Egg masses containing eggs are laid on trunks, branches, and limbs of medium to large trees
Eggs hatch in spring and nymphs search for new hosts

22. Spotted lanternfly MANAGEMENT
Scrape the eggs off host plants
Sticky bands around tree trunk
Potential for biological control
Chemical management

23. VIBURNUM LEAF BEETLE Native to Europe Secondary pest species
Discovered in North America in 1947 in Ontario
Found in Illinois (2009)
Potential for heavy defoliation of shrubs, dieback, plant death

24. LIFE CYCLE OF VIBURNUM LEAF BEETLE

25. HIGHLY PREFERRED VIBURNUM spp.
European cranberrybush (V. opulus)
American cranberrybush (V. trilobum)
Rafinesque viburnum (V. rafinesquianum)
Arrowwood viburnums (V. dentatum)

26. LESS PREFERRED VIBURNUM spp.
Sargent viburnum (V. sargentii)
Wayfaringtree viburnum (V. lantana)
Nannyberry viburnum (V. lentago)
Blackhaw viburnum (V. prunifolium)

27. MANAGEMENT OF VIBURNUM LEAF BEETLE
Prune out and destroy infested twigs after egg laying (October to April)
Plant less susceptible Viburnum spp.
Chemical treatments

28. ELONGATE HEMLOCK SCALE HEMLOCK WOOLLY ADELGID
TWO NEW HEMLOCK PESTS
ELONGATE HEMLOCK SCALE
HEMLOCK WOOLLY ADELGID

29. HOSTS OF ELONGATE HEMLOCK SCALE
Preferred Hosts
Canadian and eastern hemlock
Spruce
Less Preferred Hosts
Cedar
Douglas-fir
Pines
Yew

30. RANGE OF ELONGATE HEMLOCK SCALE
Arrived from Japan in 1908
Currently found in New York, Connecticut, Maryland, Massachusetts, New Jersey, Ohio, Rhode Island, and Virginia
Found on hemlock shipped in from an adjoining state

31. LIFE HISTORY OF THE ELONGATE HEMLOCK SCALE
Found on lower surface of needles and new cones
Light yellow to brown, flattened and 1.5 mm long
Overwinters as fertilized female or egg

32. LIFE CYCLE OF ELONGATE HEMLOCK SCALE

33. ELONGATE HEMLOCK SCALE FEEDING DAMAGE
Needles will develop yellow banding on top
Premature needle drop
Trees weaken by EHS may be vulnerable to hemlock borer and Armillaria root rot
Found along with hemlock wooly adelgid (HWA)

34. HEMLOCK WOOLLY ADELGID
Found in Oregon, California, Virginia, Delaware, Maryland, New York, Pennsylvania, and Michigan
Causes significant damage to Canadian hemlock (Tsuga canadensis) in ornamental plantings
Adults resemble copious masses of white filaments wax looking like “cotton”
Systemic insecticides are effective

36. DISTRIBUTION OF HEMLOCK WOOLLY ADELGID IN WESTERN MICHIGAN