Top 10 Nasty Insect Pests of and Youturfconference.org/images/MATEtop10treepests.pdf · Top 10...
Transcript of Top 10 Nasty Insect Pests of and Youturfconference.org/images/MATEtop10treepests.pdf · Top 10...
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Top 10 Nasty Insect Pests of Trees and Shrubs
(and How to Deal With Them!)
Daniel A. Potter, Professor
University of Kentucky
You
Insects
# 9 & 10 Web‐making Caterpillars
Eastern tent caterpillar
Fall webworm
Mimosa webworm
Non‐Chemical Control
Scrape off egg masses
Bag nests in small trees
Pole pruner
Tent Caterpillar outbreak of 2000‐2002
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Mare Reproductive Loss Syndrome
Tent caterpillars can cause horse abortions
Remove cherry trees near pastures or paddocks
Trunk injection
Bidrin®
Abacide 2®
Tree‐age®Treated
Not Treated
#8 BagwormsMajor Pest of Landscape Evergreens
Bagworms Behaving Badly People mistake them for “pine cones” (until it is too late!)
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Female bagworm is wingless, legless; never leaves her bag
Adult male is a furry moth that emerges in late summer
Male
Female lays eggs in her bag, where they overwinter
Male moths mate with female in late summer
Eggs hatch and young bagworms begin feeding in May
Bagworm Control Tips
• Handpick bags with egg masses in winter or early spring and destroy
• Target small larvae with reduced‐risk insecticide in late May or June)
Pyrethroid sprays will control all defoliating pests
bifenthrin
lambda‐cyhalothrincyfluthrin
Reduced‐Risk Products for Defoliators
Bacillus thuringiensis (Bt): caterpillars only
Caterpillars, beetles, and sawfly larvae
Caterpillars and sawflies
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#7 Sawfly Larvae
Sawfly: 6 or more pairs of fleshy abdominal “prolegs” (enough to spell SAWFLY)
No little hooks on prolegs
Caterpillar: 5 or fewer pairs with little hooks
Sawflies versus caterpillars
S A W F L Y
Red‐headed Pine Sawfly
European Pine Sawfly
Sawflies behaving badly
Sawfly pupal cases
(present in winter) Sawfly adult
“Roseslug” – a Sawfly!
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Controlling Sawflies
Effective sprays include:
‐ Acelepryn®
‐ Provaunt®
‐ Pyrethroids
Or, prune out small infestations!
#6 Lacebugs, Leafminers, Psyllids
Boxwood psyllid
Boxwood leafminer
Azalea lace bug
Boxwood pests
Boxwood psyllid: cupped leaves
Boxwood leafminer
Boxwood Pests Lay Eggs in Expanding Young Leaves in Spring
Boxwood Psyllid Boxwood Leafminer
Adult
Adult
Nymphs on new growth
Lace bugs
Nymphs on Cotoneaster Azalea Lace Bugs
Lace bugs damage many plants:
Sycamore OakHawthorn
Pyracantha, cotoneaster, andromeda Azalea
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Systemics are the way to go for lace bug, leaf miner, and psyllid control!
#5 Mite Pests
Tiny: about the size of a period (.) of 12‐pt text
Eight legs
Leaf undersides
Stippling
Fine webbing
“Warm‐Season” Mites
“Cool‐Season” Mites
Twospotted spider mite Boxwood spider mite
Spruce spider mite Southern red mite Maple spider mite
European red mite
Spider Mite Symptoms
Stippled leaves
Bronzed or browned foliage
Mite damage to burning bush
Going…..
Going…….
Gone!
Beating foliage over paper to dislodge and detect mites
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Mite Control Tips:
Use a Miticide!
(Most insecticides won’t work for mites)
Good ones include:
Akari , Avid, Floramite, Forbid, Hexygon, Kontos, Promite, Pylon, Shuttle, Sanmite, TetraSan, Ultiflora
Systemic neonicotinoids can flare mite problems on woody landscape plants
‐ Stimulates mite egg‐laying‐ Kills natural predators
Haircut for Potter’s bug lectures
#4 Japanese Beetle
Adults active from mid‐June to mid‐August
Feed on >300 plant species!
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Japanese Beetle Damage to Linden Tree, Lexington, KY, 2007
July 8July 18
Susceptible:
• Linden
• Purple leaf plum
• Purple sandcherry
• Japanese maple
• Certain crabapples
• Roses
Resistant:
• Red maple
• Dogwood
• Redbud
• Beech
• Tuliptree
• Sweet gum
Avoid Over‐planting Japanese Beetle‐Susceptible Species!
Traps contain two lures: a floral scent, and the female sex pheromone
429,562 beetles: 10 day’s catch!
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Trap placement was evaluated in 24 home landscapes
Test Plant
Trap
Traps often increase troubles with Japanese beetles!!
Many more beetles are attracted than are caught!
Effective Japanese beetle Sprays
• Acelepryn (4 weeks residual)
• Pyrethroids
‐ Onyx (4 weeks)
‐ Other pyrethroids (2‐3 wks)
‐ Sevin (1 week residual)
# 3: Scale Insects
Armored Scales
Soft Scales
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Armored Scales have a detachable, shell‐like cover made from shed skins and waxy secretions
Obscure scale on oak –an armored scale Covers flipped to
expose insects
Armored scales encrust branches or leaves; cause dieback and death of plant
Some common armored scales
Obscure scale
Pine needle scale
Oystershell scale
Euonymus scale
Pine Needle Scale
Dieback from Euonymus Scale
Cottony maple scale
Magnolia scale
Calico scale
Soft Scales
No detachable coverBody shaped like an inverted teacup
Lecanium scale
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Sooty mold fungus
Attracts wasps & ants
Soft Scale Issues….
Dripping honeydew
*&%$!!
Crawler Hatch
Scale Insect Control: Sprays
Monitor for crawler hatch. Spray options include:
‐ pyrethroids (Talstar®, Scimitar®, Tempo®)
‐ insect growth regulators (Distance®, Talus®)
‐ TriStar®
Surfactant and high volume spray may increase effectiveness
Monitoring crawler hatch with sticky tape
Phenology: The study of recurring biological events.
“The oldest science.”
The flowering sequence of plants can be used as a biological calendar to time pest management actionsppointments.
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Timing Scale Crawler Hatch by Plant Bloom:
Oystershell scale coincides with full bloom of Sargent crabapple
Euonymus scale coincides with 50% bloom of Kousadogwood
Michigan State, Ohio State, and Univ. Kentucky have on‐line phenology calendars
Phenological Sequence for Wooster, OH
Species EventRed Maple first bloomEastern Tent Caterpillar egg hatchEastern Redbud first bloomGypsy Moth egg hatchSnowdrift Crabapple first bloomBirch Leafminer adult emergenceCommon Lilac first bloomPine Needle Scale egg hatchVanhoutte Spirea first bloomLilac Borer adult emergenceBlack Cherry first bloomEuonymus Scale egg hatchBlack Locust first bloomBronze Birch Borer adult emergenceMountain-laurel first bloomJuniper Scale egg hatchLittleleaf Linden first bloomJapanese Beetle adult emergence
Pine needle scale crawlers
Scale insect control: Systemics:
May be effective against species that have a life stage on leaves
Less effective versus scale insects on bark
Scrubbing bark with soap and water can remove many scale insects
Scale Control by Ant Exclusion
Ants “tend” soft scales to get honeydew
They defend their “livestock” from predators
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When ants were excluded….Predators reduced soft scales by 60‐80%!
Sticky band excludes ants
Predators gobble up the undefended scales
#2 Borers in trees and shrubs
Some Borer‐Prone Woody Plants
Dogwood Recently transplanted or stressed hardwood trees
Ash
White birch
Flowering peach, cherry and plum
Lilac
Moth (“Clearwing”) borers
Lilac Borer
Dogwood borer
Peachtree and Lesser Peachtree borers
Banded ash borer
Clearwing borer larvae are whitish caterpillars with a brown head
Crown thinning
Clearwing Borer symptoms
Sawdust‐like frass expelled from cracks in bark
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Pupal case of clearwing borer moth that has emerged
Clearwing Borer Treatment Apply preventive bark spray (pyrethroid or Acelepryn) 1‐2 weeks after adults emerge
Residues intercept newly‐hatched larvae as they chew through bark
Treat main trunk to runoff
Timing Borer Control By Bloom of Indicator Plants:
• Lilac borer: Common lilac; full bloom
• Dogwood borer: Oakleaf hydrangea; first bloom
Flat‐headed Borers
Adults are metallic‐colored beetles
Larvae flattened
Tunnels under bark girdle branches and trunk
Flat‐headed borers leave D‐shaped holes when adult emerges
Bronze Birch Borer:
Most destructive Insect Pest of White Birch
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Flatheaded Appletree Borer:
Most destructive pest of maple trees in production nurseries
Flatheaded appletree borer also attacks many species of stressed landscape trees
Crabapples, maples, hawthorn, dogwood, many others are susceptible
Newly transplanted trees Stressed trees
Flatheaded Appletree Borer:
Bark spray with Onyx in May prevents infestation of nursery liners
Systemic insecticides are effective against flat‐headed borers
Managing wood borers:
• Minimize tree stress
• Avoid trunk wounds
• Plant well‐adaptedcultivars
# 1 Emerald Ash Borer
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Emerald Ash BorerToledo, Ohio, USA
Before (2006) After (2009)
Emerald Ash BorerAttacks & kills all sizes and species of ash
Bowling Green State University golf course
Ontario, Canada
Emerald Ash Borer Distribution: 2015
Suckering
D‐shaped holes
Diagnosing Emerald Ash Borer
Tunnels under bark
Thinning, dieback starting at top of tree
Not Treated
Systemic Treatments CAN Protect Trees from Emerald Ash Borer!
Treated
Tree can still be saved Too far gone to save
Rule of thumb: Under 30% canopy dieback, tree can be saved
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Systemic insecticides for Emerald Ash Borer
2‐3 year’s protection 1 year protection
MOST EFFECTIVE:Injection or Infusion with Tree‐Age™(Emamectin benzoate)
Several different delivery systems are available
Other systemic insecticide delivery techniques for emerald ash borer control
Soil drench
Soil injection
Lower trunk spray
www.emeraldashborer.info
You
Insects
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You can access EntFacts through the University of Kentucky
Entomology web site
Turf & Landscape Entomology