Whiteflies

Family: Aleyrodidae

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Hosts

• Field-grown and greenhouse-grown (primarily) hemp
• Ageratum
• Aster
• Beans
• Begonia
• Calendula
• Cucumber
• Grape
• Hibiscus
• Lantana
• Nicotiana
• Poinsettia
• Squash
• Tomato

Description

Adults are tiny with bright white wings and yellow-orange heads. Immature stages are inconspicuous with pale, almost translucent, flat bodies that are mostly immobile. 

Life Cycle

Egg | Nymph | Pupa | Adult

• Several generations per year.
• Populations continue from year to year in greenhouses and in warm southern climates.

Damaging Lifestage(s): Nymph, Adult

Damage Symptoms

Adults and nymphs feed with piercing-sucking mouthparts, causing leaves to turn yellow, appear dry, or fall off plants. Whiteflies, like aphids, also excrete a sugary substance called honeydew, causing shiny, sticky leaves or sooty mold growth on leaves. 

Time for Concern

During warm weather and on transplants.

When and Where to Scout

• In the greenhouse, monitor with yellow sticky cards to detect whitefly presence.
• Look for large colonies during warm weather on the underside of lower leaves. Honeydew may also be noticeable on the tops of leaves.
• Before planting, inspect transplants for whiteflies. 

Threat Level

High for greenhousegrown hemp. 

Occurrence in Utah

Whiteflies have not yet been found feeding on field-grown hemp in Utah, but whitefly damage has been found in neighboring states. 

Management

• Attract and conserve natural enemies as they often provide adequate control.
• Inspect transplants and remove any with high whitefly populations.
• In greenhouses, use biocontrol (such as hanging cards with Encarsia sp.).
• Approved insecticides are available.

When to Consider Treatment

In greenhouse production, consider treating when plants have a threshold of 10 nymphs/leaf.

Look-alikes

Aphid molted skins, leafhopper adults, scale insects.

Whitefly Insecticides

Utah-Registered Product	Active Ingredient(s)	Notes
Ancora	Isaria fumosorosea	Toxic to bees.
AzaGuard	azadirachtin
AzaSol	azadirachtin
Azatin O Biological Insecticide	azadirachtin
Azatrol EC Insecticide	azadirachtin
Azera Insecticide	azadirachtin
Bayer Advanced NATRIA Insecticidal Soap Ready-To-Use	potassium laurate
Bonide All Seasons Horticultural & Dormant Spray Oil Concentrate; Ready to Spray	mineral oil	Greenhouse use only (for commercial).
Bonide Insecticidal Soap MultiPurpose Insect Control Ready To Use	potassium laurate	Greenhouse use only.
Bonide Rose Rx 3 in 1 Concentrate	clarified hydrophobic extract of neem oil	Greenhouse use only.
Botanigard Maxx	pyrethrins	Greenhouse use only.
Brandt Ecotec Plus	rosemary oil	Greenhouse use only.
Captiva	capsicum oleoresin extract
Captiva Prime	capsicum oleoresin extract
Dr. Earth Final Stop OMRI Fruit Tree Insect Killer (RTU); Concentrate	rosemary oil	Outdoor use only
Dr. Earth Final Stop OMRI Rose and Flower Insect Killer (RTU)	rosemary oil	Ground application only to non-blooming plants.
Dr. Earth Final Stop OMRI Vegetable Garden Insect Killer (RTU); Concentrate	rosemary oil	Only to non-blooming plants.
Dr. Earth Final Stop OMRI Yard and Garden Insect Killer (RTU); Concentrate	rosemary oil
Dr. Earth Final Stop ProActive Yard & Garden Insect Killer (spray)	rosemary oil
EcoWorks EC	neem oil, cold pressed
Evergreen Crop Protection EC 60-6	pyrethrins
Ferti-lome Fruit Tree Spray	pyrethrins
Garden Safe Brand Insecticidal Soap Insect Killer	potassium laurate
Grandevo CG; WDG	Chromobacterium sub strain PRAA4-1 Cells
Kopa Insecticidal Soap	potassiums salts of fatty acid
Leaf Life Gavicide Green 415	mineral oil	Greenhouse use only.
Mammoth Cancontrol	thyme oil
Mite-E-Oil	mineral oil	Greenhouse use only.
Molt-X	azadirachtin
M-Pede Insecticide Miticide Fungicide	potassium laurate
Natural Guard Brand by Ferti-lome Insecticidal Soap Concentrate	potassium salts of fatty acids
Natural Guard Brand Neem	clarified hydrophobic extract of neem oil	Only for outdoor hemp or transplants intended for outdoor fields.
Neemix 4.5 Insect Growth Regulator a	azadirachtin
Organocide 3-in-1 Garden Spray Concentrate, Ready to Spray/RTU	sesame oil
Organocide Bee Safe 3-in-1 Garden Spray Concentrate; RTU	sesame oil
Ortho Tree & Shrub Fruit Tree Spray Concentrate	clarified hydrophobic extract of neem oil
Prizefighter	ammonium nonanoate
PureCrop1	soybean oil
Pycana	pyrethrins	Greenhouse use only.
Pyganic Crop Protection EC 1.4 II; 5.0 II	pyrethrins
Pyrethrum TR Total Release Insecticide	pyrethrins
Rango	neem oil, cold pressed
Safer Brand Insect Killing Soap Concentrate II	potassium salts of fatty acids
Safer Brand Insect Killing Soap with Seaweed Extract II	potassium salts of fatty acids
Safer Brand Neem Oil Concentrate	clarified hydrophobic extract of neem oil
Safer Brand Yard & Garden Insect Killer II	potassium salts of fatty acids
Spear T Liquid Concentrate	gs-omega/kappahxtx-hv1a
SuffOil-X	mineral oil
Tersus Insecticide	pyrethrins
Triact 70	clarified hydrophobic extract of neem oil	Older versions cannot be used on cannabis.
Trilogy	sulfur
TriTek	mineral oil
Venerate CG; XC	Burkholderia sp strain A396
Whitney Farms Insecticidal Soap	potassium laurate
Xpectro OD	pyrethrins

Photo Credits

• Adults/Parasitized - USU Extension IPM Program
• Eggs - Bert Man Koppert, Biological Systems
• Nymph - Whitney Cranshaw, Colorado State University, Bugwood.org

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