How to eliminate the White Fly

White bugs on plants? It may be white fly …! Find out what whitefly is on plants and how to get rid of it. To combat whitefly, the first thing is prevention methods, but there are also insect traps or natural remedies to eliminate whitefly that will help you put an end to this orchard pest.

If the attack of the plague has already occurred and the first symptoms and damage of the whitefly are appearing, you can follow some of the advice that we will see today about ecological remedies for the whitefly.

What is the whitefly?

The whitefly is not actually a fly, but is so named because of the appearance of its two wings. There are more than 1,500 species or types of whitefly, all belonging to the aleurodidae insect family (Aleyrodidae sp.).

These white bugs are very small (measuring only one or two millimeters) and, as their name indicates, they have a whitish color. The light color is due to a kind of wax or white powder that covers their body and serves as protection.

What kinds of plants do whiteflies attack?

The whitefly is a very polyphagous pest that can attack different crops in the garden, garden plants and indoor ornamentals.

However, we could say that the plants that the whitefly attacks with more predilection are vegetables such as tomato or pepper, cabbage, cucurbits such as pumpkin, zucchini or cucumber and leafy vegetables such as lettuce or parsley..

The whitefly in the orchard likes high humidity and temperature, so it is a more frequent pest in spring and summer (and very dangerous in greenhouses).

Whitefly symptoms and damage to plants

Although we can find them on the ground or in different parts of the plant, whiteflies lay eggs and develop, above all, on the underside of the leaves. If there is a whitefly infestation in this area of ​​the plant, eggs, larvae and adults can be found for sure. It is very important that the underside of the leaves is checked from time to time so that you are not surprised by a fairly advanced attack.

The larvae are flattened, similar to mealybugs, they are wingless and do not move either. However, despite their harmless appearance and tiny size, whitefly larvae can cause just as much damage as adults.

One of the main damages of the whitefly is the bites in the leaves. These insects bite the leaves and suck the sap until they are discolored and dry.

The first symptoms of whitefly on plants are yellow spots or specks on the leaves, which eventually dry up. If the attack persists, it weakens the plant and can stop its growth and the development of leaves and fruits.

Like aphids, whiteflies secrete honeydew. This is another of the symptoms of the whitefly infestation. The presence of this sticky sugary substance on the leaves causes other damage to plants, such as the appearance of ants that feed on it, or black rust (bold), one of the most common and harmful fungi for garden plants..

In addition, being an insect with a «biting-sucking» mouthpart, the damage caused by the whitefly can be even more serious, since it can easily transmit viruses from orchard plants if it has previously sucked the sap from diseased plants.

How to fight whitefly

As we saw at the beginning of the post, the first and most important thing to combat whitefly is prevention. The leaves of your crops (especially the leaves at the top of the plant) should be checked often to make sure there are no attacks or, if there are, to act as soon as possible.

I recommend that you take a look at the article on Pest and disease control in organic gardens, because in the section “Prevention: basis of organic control” you will find the main actions to prevent pests in garden plants.

Here I leave you some natural remedies to combat this plague with preventive measures or using homemade insecticides to eliminate the whitefly.

Ecological remedies to eliminate whitefly

• Biological pest control: Whitefly has several natural predators, such as Cales Noacki wasps, Encarsia formosa, Eretmocerus eremicus, Eretmocerus mundus. These beneficial insects will wipe out a large part of the whitefly population in the orchard (this is most used and effective in greenhouses or indoor cultivation, since if they are outdoors, the wasps can leave). Another type of biological control is the use of natural products that contain the phytopathogenic fungus Verticillium lecanii, which is very effective in eliminating whiteflies.
• Association of beneficial plants. Planting next to tomatoes and other aromatic vegetables such as calendula, Chinese carnations (marigolds) or basil will keep the whitefly away from our crops, since its smell is a strong repellent for this pest.
• Insect traps. Yellow traps are a very effective ecological method to eliminate a whitefly infestation. These insects are attracted to this color and stick to sticky traps. It’s amazing how many flies can be caught with this method: hundreds! (I leave you a photo I took in the Green Classroom-Botanical Didactic Greenhouse of the School of Agronomists). You can buy the traps or make them yourself with recycled yellow materials and some sticky substance such as honey or glue.

Natural insecticides to eliminate whitefly

• Potash soap preparations. Dissolve about 30 g in 1 liter of water and spray on the underside of the leaves, preferably once the sun has gone. If there is a strong attack and the leaves are very damaged and sticky, you can use a cloth soaked in some neutral soap or potash soap solution to clean the honeydew from the leaves. This will also help protect them from future attacks. (Make sure before buying that the product is suitable for organic farming).
• Wormwood infusion (Artemisia absinthium): boil 250 g of wormwood in 4 liters of water for about half an hour. Strain, let cool and apply directly on the groups of flies or eggs.
• Infusion of Tansy (Tanacetum vulgare).
• Garlic: crush a clove of garlic and, diluted in water, apply to the entire plant. In addition to repelling whiteflies, it acts as a defense against other pests and diseases.
• Commercial products allowed in Organic Farming, such as Neem oil, natural Pyrethrin, summer oil or Beauveria bassiana extract.

In this link you have more details about natural insecticides for whiteflies and other garden pests.

References

1. Polack, A., 2005. Integrated Whitefly Management. National Institute of Agricultural Technology. Horticultural Bulletin, Year 10, No. 31.
2. National Institute of Agricultural Technology of Argentina, 2008. Melon cultivation: whitefly. Information sheet for the agricultural sector. Agricultural Production Series, No. 17-July 2008.
3. Betancur Pérez, JF, 2012. Identification and molecular characterization of viruses transmitted by whiteflies (Bemisia tabaci) that infect tomato in the Andean region of Colombia. Doctoral Thesis in Agricultural Sciences. National university of Colombia.
4. Cerda Kelving, J. & Jimémez-Martínez. E., 2012. Management alternatives against the whitefly-geminivirus complex in tomato cultivation in Tisma, Masaya (2009) and Camoapa, Boaco (2010). La Calera Scientific Magazine, vol. 12, no. 18, p. 18-28.
5. Castresana, JE, 2016. Effectiveness of yellow sticky traps for the control of the whitefly Trialeurodes vaporarioum (Aleyrodidae) in the tomato crop Lycopersicum esculentum in the north of the Province of Entre Ríos. Doctoral Thesis. National University of La Plata, Argentina.

I hope this post will be useful to you to eliminate the whitefly. If you have any experience (good or bad) in the fight against whitefly in your orchards or organic farms, you can leave a comment, this will surely help others!