How to fight whitefly successfully

The whitefly is tiny, but it can still cause a lot of damage. If it is found on the plants, countless specimens have usually already settled and their gigantic eggs have been deposited in the area. The whitefly cannot be destroyed with a brief fight. However, there are natural and simple measures that can limit the damage and drive the whitefly away.

Recognize the whitefly

The whitefly is tiny with a body size of just 2 to 3 mm. And not always easy to recognize even at first glance. In addition, it is preferably located on the underside of the leaves, which makes immediate recognition even more difficult.

The following properties can help identify the pest:

  • White spots on the underside of leaves
  • The whitefly flies or appears to jump away when disturbed
  • The leaves of infected plants become blotchy and yellow, fall off, and are sticky
  • Fine nets can appear on the underside of the leaves

Because the whitefly releases fructose, it favors a simultaneous infestation of the plant with sooty fungus.

This is expressed in turn by black spots and speckles that appear on the leaves of affected plants.

Favorable factors
The whitefly only feels comfortable when a temperature of over 20 ° C is available to it. It only becomes really active from 23 ° C. In addition to this warmth, it also needs a high level of humidity. It should be around 70%.

The whitefly can therefore only be found outside in temperate latitudes in warm, wet months. Damp summers favor their spread.

In greenhouses and indoors, however, it can be found all year round and quite frequently. Especially on plants that come from the tropics and therefore have to be kept moist and warm. But they can also occur in winter quarters if it is too stuffy. The following measure is therefore an ideal prevention.

With ventilation against the pests

Regular and frequent burst ventilation temporarily lowers the temperature and frees the air of unnecessary moisture. So it destroys the optimal conditions for the whitefly to spread. Especially in winter, when the pests prefer to attack indoor plants, fresh air should not be used sparingly.

Incidentally, frequent ventilation also has a positive effect on health, because viruses, bacteria and other germs are also removed from the room air with the moisture and heat.
It is sufficient to open the window about three times a day for ten minutes. The heaters should of course be switched off. A more frequent exchange of air is advisable in the kitchen and bathroom, as this is where heating air and water vapor combine to create an optimal whitefly climate.

Plants particularly endangered

The whitefly can be found on almost any plant. However, these pests prefer the following plants:

  • Christmas star
  • Make it
  • Hibiskus
  • Fuchsien
  • Geraniums
  • Geranien
  • Azaleen
  • First
  • Rhododendron
  • Impatiens
  • Schönmalve
  • Purpurglöckchen

In general, plants with tropical or subtropical origins, warmth-loving plants and humid flora should be carefully monitored. So all the plants that have the same demands on water and temperature.

Frequent checks

Since the whitefly can spread very quickly due to its large clutch of around 500 eggs, the plants on your diet should be checked frequently for damage and infestation. To do this, it is sufficient to examine them about once a week – ideally when watering.

Above all, the undersides of the leaves should be examined. If there is any discoloration, particular attention must of course be exercised here.

Incidentally, the controls must also be continued for plants in hibernation. At least if the plants are quite warm or damp.

Destroying – the first measure

If one of these controls reveals that the whitefly is enjoying a plant, the infected leaves should be removed and destroyed immediately. The compost heap or unprotected household waste is not a suitable disposal site.

Instead, the infected parts of the plant should be placed in a plastic bag and soaked with soapy water. If the bag is hermetically sealed and only then disposed of, whiteflies have no chance.

The use of predators

If whiteflies can be found in the greenhouse or in the garden, parasitic wasps and wasps are the best choices. These can be purchased in stores, are comparatively inexpensive and deal with the infestation quickly.

If they no longer find suitable pests to feed on, they move on. With a responsible and numerically appropriate deployment, an uncontrolled spread or even a plague is not to be expected.

If there is an allergy to wasp stings, there are often children or pets in the garden, but these natural predators are not suitable. Neither if indoor plants are infested.

Fall against whitefly

The so-called yellow tickers or yellow traps represent a more gentle way of combating whitefly. When placed in the immediate vicinity of the affected plants, they catch the pesky pests. In order to increase the success even more, the plants should be shaken from time to time or the flies should be roused by turning and wiping the leaves.

Gentle lye treatment

If removal and the use of yellow stickers prove to be of little help, soap should be used. For soft soap, to be precise. Making a soapy solution against whitefly:

  1. Pour one liter of warm water into a bottle.
  2. Rub off about 20 to 40 grams of a bar of soft soap. This is easily possible with a kitchen grater. Likewise, a correspondingly large piece can be cut off and chopped or rasped with a knife. Liquid soft soap, on the other hand, is not suitable.
  3. The soap crumbs are added to the warm water.
  4. The bottle is now closed and shaken until the soap has completely dissolved in the water.
  5. The infected plant can now be sprayed leaf by leaf with the lye or wiped off with a soft cloth.
  6. After an exposure time of about an hour, the lye must be washed off the leaves thoroughly with plenty of lukewarm water. This is particularly quick and easy in the shower.
Tip: So that the substrate is not contaminated by the soapy water, it should be covered tightly with foil. Since this is difficult to do, a thick towel or an absorbent rag should also be spread over the foil. Prepared in this way, the planter can also be tilted, which makes treatment even easier.

Change the substrate

Whether the infestation continues or has apparently been successfully combated – the substrate should always be changed. Because briefly anesthetized larvae and adult whitefly can hide here, as can eggs. Even if there are no more specimens on the leaves, a new infestation can appear in a few weeks.

Therefore, the plant must be completely freed from the substrate. It is beneficial to rinse off the root ball thoroughly. The same applies to the location, the pots and surrounding plants. If these are not adequately cleaned, inconspicuous eggs and larvae can survive, which in turn trigger a renewed infestation.

Insects against the pests

Spiders and ladybugs are also enemies of the whitefly. And can even be used to a limited extent in the home. So if a net is noticed in the corner of the room, it should be allowed to stay in place. The flying pests get caught in it – which at least reduces their number.
Ladybirds, lacewing larvae, predatory bugs and hover flies also successfully control whiteflies. They can also be easily purchased in stores. However, they are also only recommended to a limited extent for use in rooms. In the garden, greenhouse or a demarcated winter quarter, however, they can quickly put an end to pests.

Safe insecticides

If neither soapy water nor beneficial insects help, insecticides can still be used. In order to fight the whitefly you don’t have to swing a chemical club.
Instead, products that work on the basis of fatty acids or pyrethrum help. Both active ingredients are natural and harmless to humans and animals. In addition, they do not give off an unpleasant odor and are easy to use.

If you don’t want to spend a lot of effort with the application, you should purchase it in the form of dry sticks. These can simply be plugged into the substrate and dissolve here. The active ingredients contained in it go into the earth and finally reach the roots. From here they spread through the plant and are of course also contained in the plant sap. If the whitefly suck this in on the underside of the leaf, it dries up from the inside out.

The same thing happens with the larvae. The eggs remain undamaged for the time being, which is why the following procedure has proven to be particularly effective in combating whitefly.

The right combination

Individual control measures alone do not prove to be completely successful in most cases, at least in the long term. Even the use of insecticides is only limited in time and to the plant being treated. However, if the whitefly has already laid eggs on the surrounding vegetation, even if these are not actually on the pests’ menu, the infestation will reappear within a very short time.

It is therefore important not to use just one measure, but rather to combine all of the tips suggested here with one another. The beneficial insects can be used outdoors instead of soapy water. Removal of the upper layer of soil is also recommended here. With indoor plants and in winter quarters, regardless of the size of the vessels, the substrate should be completely changed.

Conclusion
Whiteflies are annoying and can cause considerable damage. In addition, combating them is not possible without effort. But it is not impossible if the above tips are followed. Anyone who attacks from many sides right from the start and thus destroys eggs, larvae and adult whiteflies can quickly rid the native plants of the pests.

Kira Bellingham

I'm a homes writer and editor with more than 20 years' experience in publishing. I have worked across many titles, including Ideal Home and, of course, Homes & Gardens. My day job is as Chief Group Sub Editor across the homes and interiors titles in the group. This has given me broad experience in interiors advice on just about every subject. I'm obsessed with interiors and delighted to be part of the Homes & Gardens team.

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