Whiteflies

How to Identify and Get Rid of Whiteflies on Plants

Whiteflies
D. Kucharski, K. Kucharska/Shutterstock

Noticing tiny, white, fly-like insects on your plants? You may be dealing with a whitefly infestation. Here are tips on how to identify, control, and get rid of whiteflies!

What Are Whiteflies?

Whiteflies are soft-bodied, winged insects closely related to aphids and mealybugs. Despite their name, whiteflies are not a type of fly, though they do have wings and are capable of flying.

Whiteflies can be as small as 1/12 of an inch, are somewhat triangular in shape, and are often found in clusters on the undersides of leaves. They are active during the day and will scatter when disturbed, so they can be easier to spot than some nocturnal insect pests.

There are hundreds of species of whiteflies, but most affect only a small number of host plants. However, there are a few whitefly species that affect a wider range of plants, which make them the most problematic in horticulture. These whitefly species include the greenhouse whitefly, bandedwinged whitefly, giant whitefly, and silverleaf whitefly, among others. Silverleaf whiteflies, which are slightly smaller and more yellow than other whiteflies, are especially common in the southern United States. 

Where Are Whiteflies Found?

In USDA Zone 7 and colder, whiteflies are not able to survive winter outdoors, so their presence tends to be limited to indoor plants or greenhouse environments. However, if outdoors plants are bought from an infested greenhouse, whiteflies may become a seasonal outdoor garden pest. (Always inspect plants before bringing them home!) 

In warmer regions, whiteflies are capable of overwintering and reproducing outdoors throughout the year, so they can be a problem for both indoor and outdoor plants.

You’ll often start to see whiteflies in mid- to late-summer when it gets warm and humid.

Which Plants Are Susceptible to Whiteflies?

Whiteflies can be found on a wide variety of plants, from ornamental flowers to warm-weather vegetables, including tomatoes, eggplant, peppers, and okra. Some species may attack sweet potatoes, plants from the cabbage family, and citrus trees. Indoors, they will feed on most common houseplants, especially those with soft, smooth leaves.

Identification

How to Identify Whiteflies

Like aphids, whiteflies use their piercing mouthparts to suck up plant juices and, in turn, produce a sticky substance known as honeydew. Honeydew left on its own can cause fungal diseases such as sooty mold to form on leaves.

With heavy whitefly feeding, plants will quickly become extremely weak and may be unable to carry out photosynthesis. Leaves will wilt, turn pale or yellow, growth will be stunted, and eventually leaves may shrivel and drop off the plant. 

Honeydew is a sign that the whiteflies have been feeding for several days. You might also see ants, which are attracted to the sweet honeydew. 

Where to Find Whiteflies on Plants

Whiteflies tend to prefer to feed on new growth, so check around any newly unfurled leaves first.

Check the undersides of leaves—especially around the veins—for white insects, even if they aren’t immediately visible, and feel leaf surfaces for sticky honeydew. If the whiteflies are feeding, they’ll suddenly all fly off the leaves in a swarm, so it’s very obvious.

You may also find eggs laid on the undersides of leaves. This is the beginning of a new generation! When the eggs hatch, the larvae will look like teeny white ovals without legs; they don’t move but they immediately start sucking the plant juice. This is why gardeners often miss whiteflies until it’s too late. Adult females can produce up to 400 eggs, which hatch in about one week to a month after laying. They are usually laid in a circular pattern. Eggs are pale yellow when newly laid and brown when about to hatch.

whiteflies-eggs-control-identify.jpg
Whiteflies congregate on the undersides of leaves and lay their tiny white eggs in this secure spot. Photo Credit: University of Florida.

Control and Prevention

How to Get Rid of Whiteflies

To control whiteflies, there are various solutions and traps that you can use. The biggest tip is: start early! In the mornings and evenings, as you wander the garden or tend to your houseplants, check the back of the leaves for eggs or notice when little bugs “fly away” as you approach your plants.

  • Always start with blasting whiteflies (as with aphids and many other insect pests) with your watering hose or a spray bottle. This will cause them to scatter and will dislodge nymphs and eggs to some extent.
  • Consider spraying your plants’ leaves with an insecticidal soap, following the directions on the packaging. Be sure to spray the undersides of leaves, too. Follow up 2 or 3 times, as necessary. 
    • Tip: Spray plants in the evening when temperatures are cooler, as mid-day heat may cause an adverse reaction in your plant. Plus, spraying in the evening allows you to avoid accidentally spraying any pollinators or beneficial insects.
  • According to the National Gardening Association, the following simple homemade mixture should be helpful to control and deter whiteflies: Use a mix of dish soap and water. A good squirt of soap to a gallon of water should work. As mentioned above, only spray in cooler temperatures; late in the day is best. The NGA mixture is a pretty benign combination, and whiteflies are nearly impossible to get rid of, so it’s best to try more preventative tactics first, as mentioned below.
  • If all else fails and your whitefly population is persistent, you can (carefully) use a handheld vacuum every few days to remove them from your plants. This gets rid of both nymphs and adults. Just be sure NOT to empty your vacuum into a trash can inside your home afterward!

How to Prevent Whiteflies

  • Your first line of defense should be inspecting all plants for pests before you bring them home, as well as keeping any new additions away from the rest of your plants for a period of time. This will allow you to identify and curtail any pest or disease issues that appear.
  • Keeping natural predators around will prevent whiteflies from ever exploding in population. For this reason, avoid using insecticides. Ladybugs, spiders, green lacewing larvae, and dragonflies are a few of many beneficial insects that can control a whitefly population. Hummingbirds are another natural predator. Try creating a habitat that will attract dragonflies and damselflies (which also helpfully eat mosquitoes) or beautiful hummingbirds.
  • When it comes to whiteflies, avoid chemical insecticides; they’re usually resistant and all you end up doing is killing the beneficial insects—their natural predators—and the insects that pollinate the garden for a better harvest!
  • Mulch early in the season with aluminum reflective mulch, especially around tomatoes and peppers. The reflective mulch makes it challenging for whiteflies to find their preferred host plants. 
  • Set out yellow index cards coated with petroleum jelly to monitor whiteflies, especially when it comes to tomatoes, peppers, sweet potatoes, or cabbage crops. A half-and-half mixture of petroleum jelly and dish soap, spread over small boards painted bright yellow, is sticky enough to catch little whiteflies, too. To whiteflies, the color yellow looks like a mass of new foliage. The bugs are attracted to the cards, get stuck in the jelly, and die.

planting_for_pollinators_webinar_ad.png

Reader Comments

Leave a Comment

Greetings! Whiteflies have

Greetings!
Whiteflies have infested my indoor tomato garden! I live in the Great Lakes region, it's November and the room is at a constant temperature. Will the insecticidal soap work as efficiently indoors or will I need more drastic measures?

If you can them early enough,

The Editors's picture

If you can them early enough, you can use the insecticidal soap. Other solutions are:
Apply neem oil.
Set out yellow sticky traps.
Use a handheld vacuum to eliminate whiteflies by hand.

How often should you spray

How often should you spray the soap solution and when is the best time of day Ito spray your plants.

Spray on a cool, cloudy

The Editors's picture

Spray on a cool, cloudy morning or spray in the cool evening. You can spray often as it's not a toxic solution. Spray on all sides of leaves, especially undersides. Whiteflies can be challenging so you might spray every couple days.

I live in south Florida and 2

I live in south Florida and 2 of my neighbors had their yards treated for white fly. This morning I noticed a different neighbor's banyan tree is dropping moldy leaves all over my yard. It appears to be affecting my coco plums and gardenia for now. Does white fly invade and suck the life out of everything? Are there plants they don't like? Worried my efforts to save my plants will not be in vain...

Several species of white

The Editors's picture

Several species of white flies do significantly infest ornamentals in Florida--gardenias, coconut palms, and others being more common hosts, but many other ornamentals are affected. We'd recommend that you or your neighbor check if the banyan tree is indeed having a white fly problem or some other cultural, pest, or disease problem. If white fly, then there are several biological and chemical controls to use, depending on the species. It would be best if one could take a sample to your local Cooperative Extension or garden center, or have an arborist/landscape professional take a look, so that the proper controls could be recommended.
 
In general, white fly larvae and adults feed on the undersides of the leaves, sucking sap. This may leave spots on the top sides of leaves; the leaves may eventually yellow and fall off. The honeydew that the insects excrete can lead to sooty mold.
For more information, see:
 
http://www.edis.ifas.ufl.edu/m...
 
http://entomology.ifas.ufl.edu...
 
http://www.palmbeachpost.com/n...

my tomato crop grown outdoors

my tomato crop grown outdoors is heavily infested with whiteflies. i have several methods of including the one you have given above but i was successful. anything new to try

I think I have an infestation

I think I have an infestation of whiteflies on my rose of Sharon tree. These don't have yellow bodies but white. There is a distinct white bullseye kind if design on the undersides of the leaves. Also, clumps of a silk like substance is everywhere. I used your solution which seemed to kill the flying members. I don't see any larvae. Do you know what I have in my tree based on this description?

The circular spots on the

The Editors's picture

The circular spots on the leaves can be caused by a leaf spot fungi. Remove as much of the "silk" as you can and also check for spider mites.

The math solution to make the

The math solution to make the solution
5 parts water + 2 parts rubbing alcohol = 7 parts
32 oz / 7 = 4.57 oz
4.57 = 0ne part
2 X 4.57 = 9.17 (call it 9 oz)
5 X 4.57 = 22.85 (call it 23 oz)
23 oz water+ 9 oz rubbing alcohol
+ 1 tablespoon liquid soap = 32 oz solution

what % isopropyl alcohol?

what % isopropyl alcohol? most of the time its 70% but is it safe to use the stronger 90%? thats only one I buy, it has more applications for its use.I have also seen 50% and 80%.

Yes, "rubbing alcohol" is the

Yes, "rubbing alcohol" is the same--it's just the general term for isopropyl alcohol.

Thankyou georgewilson, I

Thankyou georgewilson, I would like to know if the 90% rubbing alcohol is safe to use? the %of water is only 10%,,90 and most rubbing alcohol is 70%alcohol and 30%H2o.

Thanks, very helpful. I'm

Thanks, very helpful. I'm going to try this as I will go broke buying the insecticidal soap!

Hi, after reading your

Hi, after reading your instructions on how to make the homemade mixture from the almanac, you don't indicate how much soap to alcohol/water mixture or are you saying it doesn't matter? Seems to me that it would matter, if the mixture is too diluted with water, the soap wont have much of an effect. I am loosing tomato plants and peppers to these little buggers and I would prefer to stay away from chemicals as much as possible.

Hi Benjamin, The instructions

The Editors's picture

Hi Benjamin,
The instructions are above the comments on this page.
2 parts rubbing alcohol, 5 parts water, and 1 tablespoon liquid soap. Spray the mixture on the foliage of garden plants that are susceptible to these pests.

What is the volume of

What is the volume of 'part'?

2 tsp alcohol + 5 tsp water + 1 tbs soap?
2 cups alcohol + 5 cups water + 1 tbs soap?
Lake Erie + Lake Superior + 1 tbs soap?

These instructions are for a

The Editors's picture

These instructions are for a regular-size 32 ounce spray bottle. We will fix above.

I'm not seeing the

I'm not seeing the explanation of what the volume in "parts" is. Can you put the explanation in your reply please it's not fixed above at stated, or I'm just not seeing it.

Never mind some one else has

Never mind some one else has answered it.

I need to make this for my

I need to make this for my garden plants asap, but I only have 90% isopropyl alcohol.Is it safe to use this stronger % rubbing alcohol?

HI Good Morning, I tried

HI Good Morning,

I tried mixture of chemicals in my garden infested with whiteflies but until this time nothing had happened. What should I do to control this pest?

Ren, our solutions are listed

The Editors's picture

Ren, our solutions are listed above on this page. They are non-chemical.

how can I control my tomatoes

how can I control my tomatoes leaves which are turning yellowish and dying.

Yellowing leaves is often an

The Editors's picture

Yellowing leaves is often an indicator of early blight on your tomatoes. Avoiding getting leaves wet when watering.  Make sure the tomatoes have plenty of air circulation. For the most effective control, especially during rainy periods, apply a fungicide, taking care to get good coverage on the upper and lower leaf surfaces, especially on older leaves.

Will the spray work on the

Will the spray work on the lawn too?

Yes, insecticidal soaps can

The Editors's picture

Yes, insecticidal soaps can be used on lawns. Natural predators such as lady beetles are also a good idea.

I have whiteflies on my

I have whiteflies on my hostas. I also have quite a few praying mantis in my garden. Can I get rid of the flies safely and not hurt the praying mantis?

The solutions proposed above

The Editors's picture

The solutions proposed above are pretty consistently recommended:
Spray with insecticidal soap. Follow up twice or three times.
Introduce ladybugs and spiders to help control whitefly population.
Set whitefly traps.
Or try this: 2 parts rubbing alcohol, 5 parts water, and 1 tablespoon liquid soap. Spray the mixture on the foliage of garden plants that are susceptible to these pests.
The mantis will probably be fine. Do not apply these treatments directly on it.

My condo parking lot is

My condo parking lot is infested with whiteflies. They leave nasty black residue all over my car. This needs to be scrubbed off by hand, does not come off in the carwash that I go to. What can I use on my car to keep them off?

Pages

FREE BEGINNER'S GARDEN GUIDE!

Sign up for our email newsletter by entering your email address.

BONUS: You’ll also receive our free Beginner Gardening Guide!

The Almanac Webcam

Chosen for You from The Old Farmer's Store

Sign up for our email newsletter by entering your email address.

BONUS: You’ll also receive our Almanac Companion newsletter!