Whiteflies attack different plant varieties and that is how they are classified. Common species include the ficus, spiraling, and hibiscus whitefly among others that are listed below.
Whiteflies are tiny V-shaped insects with white wings. Adult whitefly is about 0.15-0.2 inches long. They hide under leaves while feeding and laying eggs that are white with a yellow tint. If mixed with dust, whitefly eggs may appear to be brown. Those hatch into white oval-shaped larvae.
The whiteflies’ larvae can be easily identified because they are naturally glued under the leaves and they do not have wings or legs to move. When you rattle them, they will all fly at the same time leaving a cloud of white dust behind.
Characteristics of a whitefly
Whiteflies live in warm environments and that’s why they disappear in cold seasons (winter). They are insects that suck the sap out of plants. To survive, they hide themselves under the leaves. Their color easily betray them so they have to hide.
The adults have a white powder on their wings and when rattled, they fly in groups leaving behind a cloud of white-like dust in the air. With an average length of one millimeter, they normally lay eggs that are yellow or gray in color.
These then hatch into wingless larvae that look flattened and with no legs. They are also translucent and are around 0.8millimeters long.
The bugs can be hosted in many ornamental as well as vegetable plants. Their favorite plants include citrus, hibiscus, cucumber, potato, grapes, and squash.
Are whiteflies dangerous?
The fact that they suck and drain the leaves makes them very dangerous to plants. Among the things that could result include yellowing of leaves and stunted growth which will lead to reduced yields in plants.
The plants will also become more susceptible to diseases since they become weak. The sap that is sicked from plants is what keeps them healthy.
They could also transmit some viruses to the plant. These whiteflies, just like aphids, also secrete honeydew. As a result, the leaves end up being covered with a sooty mold that is black.
This will then interfere with the plants’ osmosis. A heavy infestation will make the leaves drop. This is always characterized by a yellow or light brown tint on the leaves. When a leaf is completely drained, it will move to the next.
Types of whiteflies
It is important to identify the common types of whiteflies when you want to get rid of them because this will help you in getting the right pesticide. Generally, whiteflies can be difficult to manage because they are resistant to several pesticides.
1. Greenhouse whitefly
Biological, the greenhouse whitefly is also known as Trialeurodes Vaporariorum. They are easily identified because of their white color.
If you are keen, they may appear like little moths. The adult is about 0.06 inches long with a bright V shaped wings. Those are also stained with a white like powdery dust that they leave behind as they fly in clusters.
They are always found in groups and they lay several eggs on their host plants. To locate them, check under the leaves because that is their preferred hideout.
2. Bandedwinged whitefly
Those are easily identified because of their unique wings that are full of patterns. Those can appear like black lines or spots on their white wings. When the adult is fully grown, it can achieve a maximum length of about 0.08 inches.
They are very popular in the United States of America and when you move to the warm areas, they can survive out side the house.
This means that it is easy to find them in the back yard and oud door plants. When they attack your plants, the leaves will drop down after turning yellow.
Their favorite plants include the eucalyptus, hibiscus, and citrus. They are highly destructive to those plants and can also lead to stunted growth. As soon as you identify them, get the right pesticides before they damage the entire plantation.
3. Spiraling whitefly
The spiraling whitefly is a tropical pest. It is known to attack many horticultural plants, shade trees, and ornamental plants. This insect though referred to as a fly is a bug that feeds by sucking sap from plants.
Its name is derived from the egg spirals the adult fly tends to deposit on fruits and leaves. They occur as winged adults that emerge from a sedentary nymphal stage.
Where there are no predators, the spiraling whitefly multiplies rapidly. This leads to the presence of thousands of the whiteflies on a single plant.
These whiteflies feed on the leave’s underside. A plant that has its leaves highly infested normally develops a black sooty appearance as a result of mould growing on the sugary secretion they produce.
With the damage caused on the leaves by the spiraling whitefly and the sooty substance, it becomes hard for the plant to photosynthesize. This leads to the weakening of the plant. Where the attack is severe, the plant could end up dying.
The spiraling whitefly is most active during calm and still times of the day which are mainly at dusk and dawn.
This is when they are seen flying in circular patterns near the host plant. In other times of the day, some disturbance on an infested plant will induce their flying. However, they resettle fast after that.
4. Silverleaf whitefly
Those are very popular in the northern parts of America and the adult grow up to a maximum of 0.05inches long. They can be easily identified by the fact that their wings are curved out wards making them look like a white oval tinny boat.
The locals in north America also refer to the silverleaf white fly as a vegetable whitefly. This is based on the fact that they love house hold vegetable plants like tomatoes and potatoes.
If you have a tomato plantation, the silverleaf whitefly is one of the pests you should be scared of.
They will cause the leaves to curl and turn yellow and this will cause a very low harvest. If they swarm your vegetable field in large numbers, they can wipe out the entire plantation.
5. Citrus whitefly
The citrus whitefly is a moth like white insect that is four winged. They are mostly found resting on the leaves undersides.
An adult female lays yellow eggs on tender leaves. Those then hatch to get into the nymphal stage of the fly. After that, they pupate and mature up.
Due to the fact that they are located on the underside of the leaves, controlling citrus whitefly can be difficult.
It takes the continuous use of pesticides to get rid of them. Alternating different chemicals is necessary to reduce the chances of the flies becoming resistant.
6. Ficus whitefly
The Ficus whitefly attacks the Ficus plant species. Adults have white wings that have a faint grey mark. Their eyes are dark red.
It feeds on the juices of these plants causing them to have yellowing leaves, branch die back and defoliation.
When they occur in high populations, they stunt the growth of a plant. These whiteflies reproduce fast and could become a nuisance. When the plant is disturbed, they fly readily.
The weeping fig tends to be most susceptible to the ficus whitefly. They can also be found on banyan tree, strangler fig, banana leaf fig and Cuban laurel.
For people with ficus hedges, an infestation will lead to destruction of residential landscapes. The risk of rapid defoliation and widespread infestation heighten in the spring and summer months.
To protect them, one has to control the flies. This is done through ficus whitefly treatment. The use of systematic products could help achieve this.
One could do the control themselves or employ professionals to do it. There are over-the-counter products such as Safari, Bayer Advance Tree, and Shrub Protect.
Those can be used to get rid of them. All one needs is to follow the insecticide labels to know how to go about it.
Apart from application on the leaves by spraying, one could also opt for drenching. This involves dousing the roots.
By doing so, the chemicals are allowed to systematically pass through all the leaves. While spraying may be cheaper, it is less effective. Drenching will cost more but will work better.
7. Hibiscus whiteflies
Hibiscus leaves could get infested by the hibiscus whiteflies. This may be indicated by the presence of white wax in the form of fine threads dangling from the leaves underside.
The infestation may also spread to the leaves’ upper surface. The yellow and red hibiscus plants attract these whiteflies easily.
Getting rid of them may be challenging but with a multipronged approach, the infestation can be eliminated.
Where do whiteflies come from?
In most cases, an infestation occurs when infested plants are introduced into a green house, home or outdoor garden. Another cause of whiteflies in house plants is cold weather outside. During the cold season, they move into the house looking for warmth.
This can easily make them spread from rom one plant can easily spread to other plants. It is therefore important to inspect new plants thoroughly.
In case a whiteflies’ infestation is detected, the plant should be treated before being put together with the others. In some cases, it may be important to isolate new plants for a few days so as to observe them.
When this is done, the plants should be inspected regularly and treated if necessary. This will keep the rest of the plant population safe.
These little white flies love weak plants that lack vigor and are struggling to survive. They also thrive in plants that have high levels of nitrogen compounds. They are among insects that like light and bright plants will also attract them.
It is difficult to manage an infestation because once they attack a plant and it becomes stressed, they produce glutathione which is beneficial to whiteflies. This helps in their growth, reproduction and boosts their ability to resist pesticides.
Whitefly life cycle
A complete whitefly life cycle lasts between 20 and 30 days while at room temperature. In late spring, the adult females will lay 200-400 eggs on the lower side of the leaves.
The eggs are laid in clusters and within 2 to 5 days, they hatch into tiny mobile scales. After a number of days, the scales turn into immobile larvae. These continue feeding on the juice from the plants until the time they pupate.
Due to their pale and almost translucent nature, the initial stages of the whiteflies’ life are easily overlooked and can be difficult to notice and till there is a full infestation.
The immature flies also tend to blend well with the leaves’ color that they are attached to. This makes them almost invisible and difficult to spot. The flies are capable of breeding many generations all year through especially in warm conditions.
How to control a whitefly infestation
Where the whiteflies penetrate into the garden and there is an infestation, control measures ought to be put into place to help fight it. Among some of the things that one can do include:
- In case the infestation is just starting, one could vacuum the adults from the leaves. This is best done early in the morning as the bugs are usually slow-moving at that time.
- Once done with vacuuming, the vacuum bag should be put in a plastic bag with the insects still in it. This should then be frozen for 24 hours for the insects to die.
- You could also use yellow sticky traps to capture the adults. These lure the insects into their death trap.
- In case indoor plants have been affected, releasing the parasitic wasp (Encarsia Formosa) could help.
- To control their nymphs, use insecticidal soap, garlic oil, or summer oil.
- Hosing can also be used. This sends a strong blast of water to the leaves to help in dislodging the whiteflies. It helps in getting rid of the adults.
- To get rid of whiteflies that are in their immobile nymphal or pupal stages, inspect the plants and get rid of the older leaves.
If you have indoor plants around your bedroom, you may find their larvae that look like worms in your bedding. This will only happen if there is an infestation of whiteflies on the plants.
- University of Florida IFAS Extension: Whiteflies cultural and biological control
- UC Riverside College of Natural & Agricultural Sciences: Economic Impact of the Silverleaf whitefly by Timothy Paine, Thomas bellows, and Mark Hoddle