New discoveries in science, technology, health, the environment, human culture, and history are highlighted by Live Science.

Home / HISTORY & CULTURE / How to Recognize and Avoid White Gnats and How to Get Rid of Them

How to Recognize and Avoid White Gnats and How to Get Rid of Them

2023-03-17  Maliyah Mah

You might have seen a swarm of white gnats flying around your houseplants at some point. It's also possible that there's a swarm hovering near your perennials. White gnats are almost certainly to blame for the yellowing and curling of the leaves on your plant, if you've experienced either of those symptoms.

On the other hand, the term "gnat" can refer to a wide variety of different types of flying insects. Hence, in order to properly save your plants, let's go over how to identify the many kinds of insects that are causing problems in your garden. You'll be able to find information there about how to eliminate white gnats that are specific to your situation.

Many varieties of the White Gnat

Whiteflies and woolly aphids are the two primary species that you are most likely dealing with when you are attempting to determine which one you are dealing with.

To begin, let's discuss those pesky whiteflies. In spite of their common association with flies, whiteflies are more closely related to aphids than they are to true flies. Whiteflies are members of the Hemiptera order of insects. Their bodies and wings are covered with a waxy coating that gives them their common name. Whiteflies thrive in warm climates, and in areas where they are not threatened by their natural predators, their populations can quickly increase.

The woolly aphids are the second type of pest. The excrement that these little insects generate resembles a waxy white substance, which is how they received their name. Aphids take on a fuzzy appearance as they move because the wax coats them as it moves with them. The sap of trees such as pear trees, ash trees, oak trees, elder trees, and elm trees is a favourite food of woolly aphids. They also take pleasure in tending both food and ornamental gardens

cluster of white gnats

Life Cycles

Eggs laid by whiteflies can be found on the underside of leaves, and it typically takes between six and ten days for the eggs to develop. The eggs will eventually hatch, and the nymphs will emerge. The nymphs have a cottony texture all over their bodies and have a flat, oval form to them. These nymphs go through a total of four different developmental phases, which are referred to as instars.

Out of the final nymphal stage, an adult whitefly with wings will emerge between 18 and 22 days later. Adults measure only approximately two to three millimetres in length and have a lifespan of thirty to forty days. The whitefly obtains its nourishment during the entire process by sucking plant juices from the leaves of the host plant.

The egg, the nymph, and the adult stage are the three primary phases of development for the woolly aphid. In order to mature into an adult woolly aphid, woolly aphid nymphs must first pass through four stages of development, during which they progressively become larger. Adults can be anywhere from one millimetre to three millimetres in size and have a lifespan of about 30 days, depending on the species.



There are numerous species of both whiteflies and woolly aphids, even though it is quite likely that you are dealing with one of these two pests. You are aware that different species are drawn to various kinds of host plants, and that these species also have variable degrees of success when it comes to migrating their host plants. It could be to your advantage to do some research on the specific species of whitefly or woolly aphid that you will be facing off against.

There are two primary species of whitefly.

The sweet potato whitefly and the greenhouse whitefly are the two primary species of whiteflies that should be looked for.

The sweet potato whitefly is most attracted to a wide variety of herbaceous plants (plants without a woody stem above ground). On the other hand, the sweet potato whitefly can also infest various types of woody plants. Cotton, tomatoes, peppers, crape myrtle, roses, and hibiscus are just few of the plants that fall under this category.

If you examine the nymphs of this species of whitefly when they are in their fourth stage of development, you will be able to identify it. They do not possess any waxy filaments and have a significantly reduced amount of fringe surrounding their oval-shaped bodies. Adult sweet potato whiteflies have white wings and a yellow body, and both of their wings are slightly angled upwards towards the surface of the host plant.

The greenhouse whitefly also has a very wide range of host plants that it prefers to feed on, including the vast majority of herbaceous and vegetable plants. Such examples include: avocados, lantanas, redbuds, and more.

When searching for this particular species of whitefly, you will notice that the nymphs on the fourth stage of development have long waxy filaments and some fringe on their bodies. Adults can be identified by their white wings and their bodies' yellowish cast. They do this to give themselves the impression of a triangle by holding their wings in a straight out position.

You can check the identification table that was compiled by the University of California Agriculture and Natural Resource to obtain a comprehensive listing of all the species of whiteflies and the features of each one.

Woolly Aphids Species

There are primarily two species of woolly aphids.

The woolly apple aphid and the woolly elm aphid are the two species that are most important to watch for.

The woolly apple aphid congregates in groups on the fruit, bark, leaves, and roots of apple trees. On the other hand, they have a soft spot for hawthorn and pear trees. When they feed, they frequently leave behind galls, which are abnormal growths that can be found on the bark, trunks, and branches of trees. They grow to be between 1.2 and 2.5 millimetres in length as adults.

Adult woolly elm aphids can grow to be anywhere between two and three millimetres in length and feed almost exclusively on elm trees and hawthorns. You can find them on the bark of the tree or plant, as well as on the stems, roots, and leaves. The most obvious signs of damage are the curling of the leaves and the galling of the bark and branches of the tree.

You are welcome to take a look at the comprehensive identification table that was compiled by the University of California Agriculture and Natural Resources.

Damage Inflicted

The harm that was done

The feeding habits of whiteflies and woolly aphids cause damage to your plants, which is why you should eliminate both of these pests from your garden. Whiteflies and woolly aphids are able to extract sap from the phloem of plants by puncturing the leaves with their mouth parts that are shaped like needles. In plants, the living tissue known as phloem is responsible for transporting the sugar sucrose to other parts of the plant. If the phloem of your plant is damaged, the leaves may become yellow, give the impression that they are dry, or even fall off the plant.

Honeydew is the name given to the sweet liquid that is secreted by insects such as whiteflies and woolly aphids. This sticky substance has the potential to gum up your leaves and attract ants, both of which could drive away the natural predators that would otherwise eat your bugs.

Honeydew is also the source of a fungal illness known as sooty mould, which only thrives on honeydew and spreads through it. Even though sooty mould won't directly harm your plant, it can spread to the point where it inhibits the sunlight from reaching the leaves of your plant. This could reduce the amount of fruit your fruit tree produces or cause your blooms to look wilted. This can be extremely aggravating when one is working towards the goal of developing a beautiful garden.

In addition, woolly aphids may be responsible for the transmission of powdery mildew from one host plant to another host plant. Powdery mildew is a type of plant disease that, if not treated in a timely manner, can cause plants to wither and their growth to be stunted.


The most effective method for controlling these forms of white gnats is, of course, to stop them from infesting the area in the first place. Mulches that are reflective can be of assistance here. The reflection of ultraviolet light, which occurs when reflective mulches are used, messes with an insect's ability to locate its host plant. As a result, it has the potential to avert or, at the at least, postpone the infestation of plants.

In some contexts, the control of pests can be aided by creating favourable conditions for the organisms that naturally prey on them. Lacewings, bigeyed bugs, minute pirate bugs, and the Asian multicoloured lady beetle are some of the insects that prey on whiteflies. The Asian multicoloured lady beetle is no one's personal favourite.

When it comes to the enemies of the woolly aphid, there is some overlap amongst them. Lacewings, hoverflies, and ladybirds are all predators that feed on woolly aphids, which will result in a lower overall population of the pest. Hence, permitting the presence of some of these predators will result in the elimination of both whiteflies and woolly aphids.

How to Eliminate and Prevent Whiteflies

In the event that you discover an infestation, remove any leaves that contain eggs or nymphs as quickly as possible. Alternately, you might thoroughly spray off the leaves in order to remove any eggs or nymphs that may still be clinging on the leaves. In addition, yellow sticky traps can be placed about your home to help limit the number of whiteflies. Soaps and oils containing insecticides are another method that can be utilised to lower population levels. Neem oil is a wonderful alternative because it is a natural pesticide that is harmless to both domesticated animals and wild animals.

You ought to get rid of any plants that consistently have a large number of whiteflies flying around them if you find that they are doing so. You could also try an insecticide that works systemically. Systemic insecticides are those that are absorbed by the plant and then carried throughout it, killing any insects that are feeding on the plant. On the other hand, this has the potential to aggravate beneficial insects and pollinators.

How to Eliminate Woolly Aphids from Your Garden

If you are interested in using natural remedies to treat your woolly aphid infestation, a good place to begin is by giving your plants a thorough soaking with a powerful stream of water. This will assist in removing any eggs that may have been placed under the leaves as well as nymphs that may be clinging to the plant. Rinsing on a consistent basis will help reduce the population.

Neem oil is another excellent option, as are the many different natural insecticidal soaps that are available. The vast majority of natural ones are produced by combining oil with unadulterated soap (there are no dishwashing soaps that include a degreaser or bleach in their ingredients list) (vegetable, peanut, corn, soybean, etc.). The use of these soaps is recommended since, in addition to being kind to animals and the environment, they are effective in getting rid of insects with soft bodies and little bodies, such as aphids.

It may be necessary to prune and remove branches that are infested with woolly aphids if the infestation on your plants is particularly severe. Strong insecticides are only required occasionally, but when a plant or tree is struggling under a lot of stress, you might need to use them.


Even while it can be unsettling to observe a cloud of "white gnats" hovering over your plants, you do have a number of solutions available to you for the control and prevention of whitefly and woolly aphid populations. You can keep these irritating pests out of your garden if you put in the effort and pay attention to detail.

2023-03-17  Maliyah Mah