Greenhouse Insect
Biology and
Management
Jen White & Ric Bessin
Dept. Entomology
University of Kentucky
Pest management in
greenhouses
Why are pests attracted
to greenhouses?
Lots of food
Great climate
No enemies
Outline
• Introduction to Integrated Pest Management
• Biology of common greenhouse pests
• Chemical controls
Next time:
• Biological and Alternative controls
Integrated Pest Management
Goal: Mitigate pest damage
while protecting human
health, the environment and
economic viability
• Integration of tactics
– Biological
– Chemical
– Cultural
– Physical/mechanical
• More reliable control
Components of an IPM Program
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Pest prevention
Pest identification
Monitoring and population assessment
Control action guidelines
Integration of tactics
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Biological
Chemical
Cultural
Physical/mechanical
Prevention
Keep them out!
• Inspect incoming stock
– Isolation
• Mechanical exclusion
• Weed removal
– Inside and outside GH
– No extra flowering
ornamentals
• Prevent year-to-year
carryover
– Remove residues
– Sanitize
Pest Identification
• Why is it important?
– Misidentification can contribute to failure
– Incorrect biological or chemical controls
Common Greenhouse Pests
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Mites
Thrips
Whiteflies
Aphids
Fungus gnats
Shore flies
Mealybugs
Others…
Characteristics
–Small
–Hidden
–Short life cycle
–Numbers build fast
Relative Sizes
Shore fly
Aphid
Thrips
Mealybug
Whitefly
Mite
Fungus gnat
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Mite identification
• Tiny
• Webbing
Mite identification
• Tiny
• Webbing
• Eight legs, no wings
– NOT insects
• Two spots –
• Two spotted spider mite
• Other species
– Lewis, Broad, Cyclamen
Spider Mites
• Attack 300 + species of plants
• Life cycle in 8+ days
• Females lay 100+ eggs
• Sap feeders
• Under leaves, around buds
• Prefer tender leaves
Two-spotted
spider mite
Mites: Monitoring
• Scouting
– look for stippling, mottled leaves
– webbing
– premature leaf drop
• Examine under leaves
Mites: Management
• Cultural
– Reduce plant stress
– Spritz with water
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Thrips Identification
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Tiny
Yellow-ish
Linear
Most common:
• Western flower thrips
Thrips Damage
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Deformed leaves
Decaying flowers
Silvery, flecked scars
Black fecal spots
Thrips Biology
 Pierce plant cells
 Young growth and flowers
Tightly furled
 Mainly females
 150 to 300 eggs
 Life cycle: 12+ days
 Vector tospoviruses
 Impatiens necrotic spot virus (INSV)
 Tomato spotted wilt virus (TSWV)
Western flower thrips
In soil
In plant
Thrips: Monitoring
 Early detection
 Blue or yellow cards
 Minimum of 3
 Placed near doors/vents
thrips sensitive plants
 1 per 2000 ft2 minimum
 Placed just above canopy
 Can do a subset of grids
 New cards periodically
 Tap method
 Same person, regular basis (weekly)
Thrips: Management
Cultural Control
Remove weeds (that may
harbor viruses)
Crop alternation
Petunia as virus indicator
Western flower thrips
plant
Sensitive to virus
Not systemic
Use vegetative plants
Blue plastic plate to attract
“Cascade blue”
“Summer madness”
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Melon or cotton aphid
Aphid identification
Melon or cotton aphid
Pear shaped body
Cornicles = “tailpipes”
Most common species
>135 plant families
Green peach aphid
>125 plant families
Potato aphid
Whitney Cranshaw
>90 plant families
Joseph Berger
Aphid Biology
High reproductive rate
– 100 live young/female
– Asexual
– Live birth
– Life cycle 7-10 days
Remove sap
Produce honeydew
Aphid Damage
• Stunt plants
• Curling, cupping of
leaves
• Sticky honeydew
– Sooty mold
• Transmit viruses
Aphids: Monitoring
Scouting
Yellow cards:
caution!
Insects on stems,
fresh growth, under
leaves
Sticky honeydew on
leaf surface
Most
aphids
don’t have
wings!
Aphid Management
• Avoid excess Nitrogen
Whitney Cranshaw
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Whitefly Identification
Greenhouse
Trialeurodes vaporariorum
Sweet potato or Silver leaf
Bemisia tabaci
Photo credit: Gaucho
Ronald Smith
UGA857007
Banded winged
Trialeurodes abutiloneus
Whitefly Identification
Greenhouse
Trialeurodes vaporariorum
Sweet potato or Silver leaf
Bemisia tabaci
Whitefly Biology
All stages under leaf
Sedentary immatures
Life cycle in 1 month
Highly visible
MANY host plants
Greenhouse whitefly
Whitefly Damage
Yellowing and discoloration
Stunt plants
Honeydew and mold
Virus transmission
Whiteflies: Monitoring
– yellow cards
– plant inspection
• Undersides of leaves
• Honeydew
• Sooty mold
• Shake plant for adults
Sweet Potato Whitefly
Whiteflies: Management
Cultural control
Plant-free periods
 Time depends on
temperature
->cooler temps,
keep plant-free
longer
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Mealybugs
“Big”: ¼ inch
Waxy, cottony, fringed
Sucking insects
– produce honeydew
– stunt plants
Attack all parts of plant
Life cycle: 1 month
Reduce marketability
Mealybugs: Monitoring
Scouting
White flecks on
midribs, leaf axils, leaf
underside
Honeydew and sooty
mold
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Fungus Gnats
 Small, delicate flies
 Feed on root, stems,
decaying debris
 Need damp media
 Life cycle 1 month
 May promote diseases
– Pythium, Verticillium, Botrytis
Watch pet (wet) plants !
Fungus Gnats: Monitoring
Yellow cards
Horizontal orientation
Potato disks
http://www.omafra.gov.on.ca/english/crops/facts/06-079.htm
Fungus Gnats: Management
Cultural control
Less water!
Remove standing water
Sterilize/contain compost
Common Greenhouse Pests
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Mites
Thrips
Aphids
Whiteflies
Mealybugs
Fungus gnats
Shore flies
Others…
Shore Flies
• Small, robust flies
• Feed on algae
• Must have damp media
• Leave frass on plants
• May move Pythium
spores
Shore Flies: Management
• Cultural Control
– Eliminate algae
Build an IPM Monitoring Program
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Start simple
Careful inspection
Scout at least once per week
Designate pest management units (PMU)
Have some prior knowledge of problems
Keep good written records (database)
Thresholds
• Why use them?
– Help maintain pesticide efficacy
– Reduce disruption of cultural practices
– Minimize phytotoxicity
– Increase profit
• How to establish thresholds
– From research
– Systematic monitoring, historic records
– Experiment
Greenhouse Insecticides/Miticides
• Food crops vs. ornamentals
• Read labels carefully
• Must have crop on label and no greenhouse
restrictions
• Crop safety (new plant types/chemicals)
• Prefer selective materials
– More compatible with biocontrol
Active Ingredients
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pyriproyfen:
spiromesofen:
spirotetramat:
pyridaben:
acetamiprid:
thiamthoxam:
abbamectin:
pymethozine:
dinotefuran:
imidacloprid:
Distance/Distance
Judo/Oberon
Kontos/Movento
Sanmite/Nexter
Tristar/Assail
Flagship/Platinum
Avid/AgriMek
Endeavour/Fulfill
Safari/Venom
Marathon II/Admire
Ornamental formulation/ Vegetable formulation
Ornamental Products with Vegetable
Uses
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Tristar (acetamiprid): Some transplants
Kontos (spirotetramat): Some transplants
Distance (pyriproxyfen): Tomatoes
Talus (buprofezin): Tomatoes
Pylon (chlofenapyr): Fruiting vegetables
Floramite (bifenazate): Tomatoes
Tetrasan (etoxazole): Tomatoes
Vegetable insecticides/miticides
Without GH restriction
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Sevin
Malathion
Orthene
Mustang max
Pounce
Baythroid
Asana XL
Proaxis
Danitol
Warrior
Without GH restriction
• Admire
• Belay
• Venom
• Distance/Knack
• Fulfill
• Dipel
• Courier
• Agri-Mek
• Acramite
These can be used in the greenhouse so long as the crop is on the label
Prohibited Vegetable Insecticides
With GH prohibition
• Diazinon
• Endosulfan
• Assail
• Platinum/Actara
• Radiant
• Proclaim
• Beleaf
• Rimon
• Intrepid
With GH prohibition
• Avaunt
• Oberon
• Movento
• Coragen
• Portal
• Belt/Synapse
Systemics for Ornamentals
Product
Systemic Target pests
IRAC Class
Marathon II
Yes (↑)
Aphids, WF, soft scale, fungus gnats, leafminers
4A
Flagship 25WG
Yes (↑)
Aphids, WF, fungus gnats, leafminers
4A
Safari 20 SG
Yes (↑)
WF, mealybugs, aphids, soft scale, fungus gnats,
leafminers, armored scale
4A
Kontos
Yes(↑↓)
WF, mealybugs, aphids, soft scale, leafhoppers,
scale crawlers
(vegetable transplants: Fruiting and leafy)
23
No
WF, mealybugs, aphids, leafhoppers, thrips,
leafminers, scale
(Vegetable transplants: Fruiting, leafy, cucurbit,
cole, and bulb)
4A
Tristar 30 SG
IGR Foliar Sprays for Ornamentals
Product
Type
Target pests
IRAC Class
Distance 0.86EC
IGR
WF, scale, fungus gnats, shoreflies
(Greenhouse tomatoes (>1”), bell pepper,
eggplant)
7D
Talus 40 SC
IGR
WF, mealybug, leafhoppers, scale crawlers
(Greenhouse tomatoes)
16
Pedestal 0.83EC
IGR
WF, thrips, caterpillars, leafminers
15
Ornazin 3% EC
IGR
WF supression, many other pest groups
(brassica crops, cucurbits, eggplants, herbs and
spices, legumes, peppers, tomatoes, and other
miscellaneous crops grown in greenhouses)
UN
Foliar Sprays for Ornamentals
Product
Aria 50SG
AI
flonicamid
Pests targeted
Aphids, WF, leafhoppers, mealybugs, scale
stink bugs
IRAC class
9C
Conserve 1SC
spinosad
Caterpillars, thrips, leafminers
5
Decathlon 20 WP
cyfluthrin
Thrips, beetles, caterpillars *
3A*
TalstarOne 0.67 EC
bifenthrin
Thrips, beetles, caterpillars, plant bug,
broad mites *
3A*
Thrips, beetles, caterpillars, plant bugs*
3A*
21A
Tame 2.4EC
fenpropathrin
Hachi-Hachi
tolfenpyrad
Thrips, aphids, scale, leafhoppers, whitefly,
caterpillars
Pylon
chlofenapyr
Spider mites, broad mite, rust mites,
cyclamen mite, beet armyworm, loopers,
thrips, caterpillars
(greenhouse fruiting vegetables 0-PHI)
13
Endeavor 50 WDG
pymetrozine
WF, aphids
9B
Mavrik Aquaflow
Mesurol 75W
Tau-fluvalinate Aphids, WF, mites, thrips, caterpillars
3A*
Thrips, slugs, snails
1A
methiocarb
Miticides for Ornamentals
Product
AI
Mites/Pests targeted
IRAC Class
Akari 5SC
fenpyroximate
Spider mites, broad mites, cyclamen mites,
rust mites, WF, mealybugs
21A
Judo 4SC
spiromesifen
Spider mites, broad mites, cyclamen mites,
rust mites, WF
23
Avid 0.15EC
abamectin
Spider mites, broad mites, cyclamen mites,
rust mites, WF, aphids, thrips, leafminers
6
Floramite 2 SC
bifenazate
Spider mites
(greenhouse tomatoes)
UN
Shuttle O
Acequinocyl
Spider mites
20B
Tetrasan 5 WDG
Etoxazole
Spider mites
(greenhouse tomatoes)
10B
Ultiflor
Milbamectin
Spider mites
6
Pylon
chlofenapyr
Spider mites, broad mites, cyclamen mites,
rust mites
13
Ovation
Clofentezine
Spider mites
10A
Sanmite
pyridaben
Spider mites, broad mite, WF
21A
Hexygon
Hexythiazox
Spider mites
10A
Ornamental Insects - Chemigation
• Products that allow for some chemigation
uses
– Marathon II
– Flagship
– Safari
– Kontos
– Conserve
– Ornazin
-- Sevin
-- malathion
-- Mustang Max
-- Pounce
-- Baythroid
-- Asana XL
-- Proaxis
-- Warrior
-- Admire
-- Venom
-- Dipel
Resistance Management
• Only treat if needed
• Rotate to a different IRAC class with each pest
generation
• Do not tank mix products in the same
chemical class
• Utilize biological control