Whiteflies (also known as whiteflies, of the order of Rhynchota Homoptera - present in more than 1500 species) are insects that resemble aphids or small white moths. They gather in groups and reproduce in large numbers on the underside of the leaves. Nymphs and adults damage plants directly by feeding on them and transmitting diseases. When the infestation reaches the roots, it is difficult to eradicate it. You may need to apply several treatments over a period of several weeks, and you may even be forced to cut the plant.
Steps
Method 1 of 4: Using Natural Solutions
Step 1. Use the vacuum cleaner
Grab a small hand vacuum or attach the furniture cleaning attachment to a regular vacuum cleaner. Move around the infested plant and turn on the appliance to vacuum the flies on the underside of leaves and foliage. This is a quick, simple method that allows you to eliminate insects from all stages of the life cycle - from the larvae that have yet to mature, to the adult specimens that gnaw the plant. This solution is most effective if you put it into practice as soon as possible, as soon as you notice the infestation.
When the bag is full of flies, remove it from the appliance; close it in a sealable plastic bag and leave it in the freezer for at least 24 hours to kill the bugs. Once they are dead, you can empty the bag into the garbage can
Step 2. Remove severely diseased leaves and branches
Use gardening shears and cut as much as possible without killing the plant. If necessary, you can also remove the leaves by hand. Look for white eggs and wingless flies that stick to the underside of the leaves. When the infestation is severe, the leaves are covered in a layer of sticky or waxy - almost honeyed - liquid that is produced by the nymphs as they feed on the plant's sap. The leaves turn pale and withered.
- Only prune the plant to the point where it does not jeopardize its health. If it is a particularly delicate variety, you should only remove the most affected leaves. If it is a sturdy plant, consider reducing it to the stem to stop the development of the infestation.
- Properly dispose of diseased leaves. Burn them or seal them in an airtight bag. If you don't handle this plant material with care, whiteflies can still spread.
Step 3. Prepare to repeat treatments
Whiteflies follow a four-stage development: the eggs hatch into nymphs, then become pupae and eventually adult specimens. Each method typically affects certain stages of the insect life cycle. So if you are following a technique that kills adult birds, you will need to keep using it until all the eggs have hatched and the flies have reached maturity. You will need to act quickly and consistently to make sure all newly grown specimens do not lay any more eggs.
- Adult nymphs and flies are the only ones that cause damage to the host plant. Young insects, if not eradicated, grow and become more harmful to the plant.
- To know precisely when to apply the treatment, check the life cycle and phases of the specific whiteflies that you need to eradicate. Among the various species, we mention Aleurothrixus floccosus, Bemisia tabaci, Dialeurodes citri and Parabemisia myricae, each with life cycles of different duration.
Step 4. Wash the infested plant with soapy water
Pay particular attention to the underside of the leaves, where most flies live. Remember that this method only kills adult specimens. Wash every 3-4 days to get rid of new parasites that have left the pupa state. Depending on the species, you will need to continue this treatment for several weeks until you have eradicated the entire infestation.
If you use a very concentrated soapy solution, try to spray it at the end of the day to avoid burning the leaves
Step 5. Introduce a natural predator
Several insect species love to feed on whiteflies, and you may be able to control the infestation by bringing the right predator into your garden ecosystem. This depends on the type of whitefly you need to get rid of. Consider chrysopids, ladybugs, anthocorids, geocoris, wasps, and nabidae.
Be very careful when intentionally introducing new insect species to the garden. Predators can deal with whitefly infestation, but you may find yourself dealing with a large colony of new parasites. Do your research before taking action
Method 2 of 4: Using Traps
Step 1. Use yellow fly paper
You can buy it at garden stores or make a homemade one. Get a sturdy yellow surface (wood or cardboard) and cover it with slow-drying adhesive. Glue, honey, motor oil or petroleum jelly are perfect. Whiteflies are believed to be attracted to yellow; when they come into contact with the trap, they can no longer free themselves from the glue.
- If you have decided to make the trap, you will need to reapply the sticky substance when it dries. The glue, for example, could dry out within hours or minutes. Engine oil or petroleum jelly may have less immediate effect, but they do not quickly lose their adhesive power.
- If you have decided to use a spray, a wash or introduce natural predators, remember to remove the traps.
Step 2. Place the traps near the leaves
Whiteflies tend to cluster on the underside of plant leaves, and traps will be most effective if they are close to their natural habitat.
Step 3. Know when to remove them
Remove them when most of the insect population has died and when you can only catch a few specimens per day. The traps could also kill the natural predators of whiteflies; therefore they should not be used for small infestations, unless predators are able to keep parasites under control. If the whitefly population starts to grow again and the infestation returns, you can calmly decide to put the traps back.
Method 3 of 4: Remove White Flies with Repellents
Step 1. Keep whiteflies away with other plants
The carnation of india is effective, as well as the tropaeolum. Place these species near garden plants to prevent whiteflies from infesting them again. Be aware that this is a preventative measure and not a solution to existing infestations.
Tagetes and calendula are not very effective as repellents. So be sure to buy the right plant variety. If in doubt, go to the nursery and specifically ask for plants to ward off whiteflies
Step 2. Spray the plants with a mixture of soapy water and denatured alcohol
Pour two parts of alcohol and 5 parts of water into a 10-liter spray diffuser. Add 15ml of liquid dish soap. Spread the mixture on the leaves of plants that are at risk of infestation. If you don't overdo it, the liquid shouldn't do any harm to most plants and may prevent insects from laying eggs.
Consider using a natural vegetable oil spray like Neem
Step 3. Spread some vermicompost at the base of the plant
This product, when added to fertilizer for infested plants, is able to repel flies within a few weeks or a month; moreover, it is rich in natural nutrients that favor the development of the plant. Ask your gardening supplier for it.
Step 4. Cover the ground with a reflective material
Spread a layer of aluminum foil or reflective plastic mulch around plants that are susceptible to infestation. In this way, adult insects have a harder time finding plants and are unable to lay eggs.
- When using this method, you must take into account the administration of water. Plants that are surrounded by plastic mulch need a drip irrigation system.
- Do not spread mulch when temperatures are high, otherwise the plants will overheat.
Method 4 of 4: Using Chemicals
Step 1. Understand the risks and benefits of insecticides
On the one hand, commercial pesticides are sometimes an effective solution for getting rid of insects quickly. Whiteflies, however, are notoriously resistant to chemicals; in addition, these substances are toxic to other organisms living in the same ecosystem - including plants, beneficial garden insects, pets, wildlife and even your own family. Try to use them only as a last resort.
Step 2. Know that whiteflies easily become resistant to pesticides
In fact, the eggs and pupae are able to withstand the most common insecticides. If you still decide to use these chemicals, remember to change them in rotation over several days to prevent the insects from adapting. In any case, the chances are high that the flies will get used to the pesticide and that a super-resistant strain of parasites will develop!
Warnings
- Repeated applications are recommended to keep the whitefly population under control.
- Insecticides are effective, but they are also dangerous if swallowed. Most of the products used against whiteflies have been linked to the death and massive reduction in the number of bees, which are indispensable for pollination of flowering plants.
