Greenhouse Whiteflies are tiny pests that are a scourge, causing gardeners anxiously looking for ways to get rid of these harmful pests. It’s a world-wide problem, and the use of chemical insecticides has created a whitefly monster. Now immune to the most common pesticides, there will come a point where any commercial or residential insecticide may no longer work.
Whiteflies do not have to be the death of your garden! Insecticidal soap is becoming the most accepted form of control. Consider this: pesticides are now known to go more than skin deep on fruits and veggies, meaning you and your family are ingesting these harmful chemicals. You should be looking for safer alternatives. Insecticidal soap is safe to use, gets fast results, and is a solution that whiteflies cannot become immune to.
Whiteflies Destroy Plants and Transmit Plant Disease – Ugh!
They’re tiny, BUT they work in huge numbers to devastate your house plants, greenhouse plants, ornamental grasses, vegetable plants, and the world’s food supply. Most of you will be the victim of the whitefly at one time or another. It is a major pest that attacks numerous fruit, vegetable and ornamental plants, both indoors and outside. In fact, these thirsty pests not only feed on just about everything green, they also transmit any number of plant diseases. Begomovirus, or BGMV, is considered one of the worst, causing considerable economic damage to food producers when infecting tomatoes, beans, cotton, casava and squash. There are 445 species of this virus alone; however, whiteflies are known to spread 60 different viral plant diseases.
Fruits and Vegetables Whiteflies are Attracted To
Besides ornamentals, palms, weeds, poinsettias and countless other plants, the fruits and vegetables most affected are: Avocado, Cantaloupe, Carrot, Citrus, Cucumber, Eggplant, Gourds, Grapes, Lettuce, Peas, Pepper, Potato, Sage, Squash, Strawberry, Sweet potato, Tomato & Watermelon.
Silverleaf Whitefly
In addition to the Greenhouse Whitefly, the Silverleaf Whitefly is becoming more prevalent. Your plants are likely to be attacked by either one of these species; though the physical differences may seem insignificant, the damage they are both capable of causing can be catastrophic. They often go unnoticed until the damage is done because they attack the undersides of the leaves. This keeps them out of the direct sun and out of sight, meaning the first preventative measure is to check the undersides of random leaves throughout your garden. Focus especially on your tomatoes, squash and watermelons.
How the Whitefly Damages Plants
An adult female Greenhouse Whitefly will lay an average of 50 to 150 eggs. Though the Silverleaf Whitefly is smaller, she can lay up to 7 times that number of eggs! The life cycle of both is also similar. They grow from eggs, which hatch in 5 to 10 days, depending upon the average ambient temperature. When they hatch, a crawler emerges, travels a short distance, and then starts voraciously feeding. THIS is when they start damaging your plants. From crawler to nymph to pupa takes about two weeks. The adult female will emerge from the pupa about a week later and will start laying eggs almost immediately. Her average life span is only 6 days, so she makes the most of it. She feeds with sucking mouth parts that extract the sap from the phloem of your plants. The phloem is the living tissue of your plants that conducts nutrients downward from the leaves. Without these sugars and other metabolic products, plant death occurs relatively quickly.
Signs that You Have Whiteflies
- Yellowing leaves, yellow-spotted leaves and curling leaves can all be symptoms.
- Eggs will normally be laid in a circular pattern. They’ll either be opaque or slightly yellow, depending upon whether it is a Greenhouse or Silverleaf Whitefly. The eggs will be laid on the undersides of your plants’ leaves.
- The nymph and pre-pupa stage will see the emergence of tiny white legs or fibers all around the small oval in the Greenhouse Whitefly though not so much in the Silverleaf Whitefly.
- As they reach pupa stage, they may look like fish scales on the backs of your plants’ leaves.
- The most obvious sign is if you are enveloped in a white cloud as you bend down to inspect your garden plants. By that time, your infestation is probably quite advanced and at least partial plant death may be occurring. (Silverleaf Whiteflies will be smaller and more yellow than the white.)
- Adults secrete a sweet substance called honeydew as they suck the life out of your plants; this will attract ants in droves, another clear indicator of a Whitefly infestation.
- The secreted honeydew is also the perfect growing medium for sooty mold. This is a black sticky mess that is impossible not to notice, but even more difficult to deal with than the Whiteflies. An ounce of prevention is worth a pound of cure.
Get Rid of Whiteflies, the Natural Way
As stated above, there are pesticides to combat the problem…for now. It is important to remember that every time you use a pesticide, you are contributing to a future generation of Whiteflies that will be immune to the pesticide you use today.
So how do you get rid of Whiteflies without creating more immunity?
We recommend organic means to control this stubborn and adaptable pest. There are, of course, natural enemies of the Whitefly, such as Green Lacewings, Ladybirds (Ladybugs), Minute Pirate Bugs, Big-eyed Bugs, and Damsel Bugs. You can either buy them in egg form or as adult insects from commercial enterprises, or you can grow plants that will attract them. Lacewings and ladybugs are both attracted to fern-leaf and common yarrow (also known as achillea), fennel, dill and cilantro/coriander. Read more about how to attract beneficial insects to your yard.
But, if you already have a Whitefly infestation, you don’t have the time or the luxury to wait for plants to grow. Even if you were to buy adult-sized plants, it will take time for the word to get out to the brigade of insect assassins to gather for the Whitefly buffet in your garden. You need something now and you need something fast acting (remember, it only takes them about 3 weeks to go from egg to egg-laying adult).
Need Help ASAP? Try Insecticidal Soap
The most common and safest organic method to get rid of Whiteflies fast is an insecticidal soap. Simply spray Safer Insecticidal Soap on the undersides of the infected plants’ leaves. Do it either in the very early morning or in the late evening when the temperatures are below 85°F. This is when the Whiteflies are not actively flying, ensuring destruction of the adults. Insecticidal soap kills by penetrating the outer shells of these soft bodied insect pests, smothering, dehydrating, and causing death in just a few hours. Insecticidal soap is non-lethal to beneficial insects and can be used indoors or out. A 32-ounce ready-to-use bottle will treat about a 1000 square foot garden plot. It is gentle on your most prized ornamentals and vegetables, but lethal for Whiteflies. Additionally, it has no unpleasant odor. Win-win!
Garden tip: Always check for Whitefly infestation prior to bringing home new plants. It will save you a world of heartache. And since Whiteflies can attack at any time, we recommend having insecticidal soap on hand. This will ensure that you’ll be ready to destroy the Whiteflies before they have a chance to become a monumental problem!
