Whiteflies

Family: Aleyrodidae

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whitefly adults Whitefly adults.

whitefly eggs and predatory mite
Whitefly eggs with a predatory mite.

whitefly nymph
Whitefly nymph.

parasitized nymph whiteflies
Live and parasitized (black) whitefly nymphs alongside adults.

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

Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.