whiteflies on cannabis

Most Common Pests In Cannabis: White Flies

White flies affect all plants, including cannabis. They hide on the underside of the leaves, where they reproduce and suck on the nutrients your plant has.

1. What Are White Flies?

White-flies are sap-sucking aphids that hide on the underside of the cannabis leaves. These white moth-looking bugs feed on the contents of your plant’s leaves, draining out its energy. Lucky for you, they can be easily controlled and eliminated with insecticidal soaps, yellow sticky and a good airflow.

These tiny white moths feed on the nutrients your plant holds and glue their eggs to your plant, making it difficult to remove them without damaging it.

They can reproduce super fast, being able to lay up to 300 eggs that will hatch in around 24hs.

Note: Even though they’re called flies, they’re not flies at all. White flies are related to sap-sucking aphids.

2. What Do White Flies Look Like?

These bugs looks like a tiny white moth, they can grow up to 2mm long, have wings, antennae and can easily be spotted flying around your plant if you shake it a little bit.

They usually have fluffy-looking legs and depending on where you live, they can have red eyes and a yellowish head.

3. Where Are They Found?

White flies can be found on any part of the plant, although they usually hide on the underside of the leaves, where they lay their eggs.

It can be fairly easy to spot them, because they will fly if you shake your plant.

So if you shake it and look closely, you will be able to see them, despite their small size.

4. What Do White Flies Do?

White flies feed on the nutrients your plant contains, just like spider mites , they bite the leaves and suck out their content.

They can lay up to 300 eggs, which can hatch in a day and completely mature in around four weeks, making it a pest that spreads fast.

The eggs will hatch and the new born white flies will start feeding on your plant, this is super dangerous because white flies can carry diseases that can gravely affect your plant.

5. White Flies Symptoms

You can find signs of white flies since the beginning, although the yellow spots they leave when feeding on your plant can be confused for other things, there is a way to be sure white flies are attacking your plants.

To spot them, you need to shake your plant, this will cause them to fly off and you will clearly see them.

Another way is to check the underside of fan leaves for eggs, you should be able to see small white eggs glued under your leaves.

Signs that a white flies infestation is getting serious is the yellowing and drying of the leaves.

At this stage, leaves will start to die and fall off, and you will start to see a reduced growth and overall development.

6. How To Prevent Them?

There’s not much you can do to prevent white flies, it is crucial to have a good air flow because this will cause them to not feel safe and look for another place to lay their eggs.

Other than that, you should check your plants thoroughly everyday.

You can also place yellow sticky traps all throughout your growing space, although this won’t exactly prevent them but you will see when they start to appear.

7. How To Deal With Them?

If you happen to get white flies you should spray your plant with organic insecticides and only move on to more aggressive insecticides if they’re not working.

You can deal with them with Neem Oil or insecticidal soaps.

Remember everything you spray on your plant can affect its growth, especially in the flowering stage, where it can affect the smell, flavor and effect your buds will have.

8. In conclusion

White flies won’t risk your harvest unless you let them be for a long time.

Even though they reproduce quite fast, it will take a lot of white flies to kill your plant.

Your plant will go through a process of slowly running out of nutrients, yellow and the leaves falling off before it starts dying, so you have a fair amount of time to deal with them.

As always, remember the best way to avoid having any problems is growing in a good environment and checking for any kind of bugs everyday.

White flies affect all plants, including cannabis. They hide on the underside of the leaves, where they reproduce and suck on the nutrients your plant has. 1.

Cannabis And Whitefly: How To Control And Prevent Them

Whitefly affects cannabis growers and regular gardeners around the world. Read on for a detailed look at this common garden pest and how to control/prevent an infestation in your garden.

Whiteflies are a common garden pest that have the potential to wreak havoc on your cannabis grow.

In this article, we look at whiteflies, what they are, how to get rid of them, and how to protect your grow against future infestations.

For more articles like this, grow tips and much more, remember to bookmark our blog. Also make sure to check out our earlier post for more tips on cannabis pest prevention.


Whitefly is a common garden pest that affects a variety of plants, including Cannabis. They behave very similarly to spider mites and are usually found on the underside of leaves where they steal essential nutrients from the plant.

Whiteflies look like tiny white moths with yellow bodies and are roughly 2 millimeters long. Adult flies are usually found on the top parts of plants while nymphs are usually found lower down.

Whiteflies usually lay eggs on the undersides of leaves. Eggs are usually greyish or yellow and feature a cone-like shape. Adult whiteflies can lay up to 400 eggs, which usually hatch within a week.

Eggs hatch into flattened nymphs (often called crawlers) which feed on the plant for about a month before developing into adult whiteflies. Adult flies usually live for roughly 4 weeks.


Whiteflies are relatively easy to spot. Adult flies are usually found flying around the plant or are grouped on the underside of leaves. Shaking a plant will cause the adult flies to fly away, making them easier to see.

Eggs are normally deposited in circular groups of roughly 30-40 and can be found on the undersides of leaves.

When feeding, whitefly punctures the leaves of the plants in order to suck nutrients from them. This leaves white spots on the top side of leaves, which is yet another clear sign that you’re plant is infected, even if you can’t directly spot any flies on your plant. Large populations may cause leaves to become yellow or die off completely.

Whiteflies usually consume more plant nutrients than they can digest. They excrete these excess nutrients as a sweet, sticky substance known as honeydew. If your plants are infested with whitefly, keep an eye out for honeydew on the leaves of your plants as it acts as a growth medium for a black, sooty mould that can hinder a plant’s ability to photosynthesize.

Honeydew also attracts ants, which can further interfere with the presence of other natural whitefly predators, potentially worsening the situation in your grow room.


As with any pest, it is always best to take preventative measures against whitefly to begin with. It is always harder to get rid of a pest than prevent one, and whiteflies can be particularly tricky to manage in large populations (which don’t take long to form).

Like when dealing with spider mites, we suggest you address any environmental factors that might be causing your infestation first, then follow up by hosing down and pruning your plants.

As always, we suggest you stay away from any chemical pesticides since they may kill off other insects that naturally prey on whitefly. Plus, most garden pests are good at building up resistance to pesticides, which may make matters worse in the future.


Whiteflies like warm weather and thrive in conditions where there are no (or few) predators around to prey on them. Therefore, it’s important to make sure that your grow room is free of dust and any other insects that might naturally interfere with whitefly predators (such as ants).

Also, make sure your grow room temperatures aren’t too high (between 20 and 25ºC or 68 and 77ºF is ideal).

If you’ve noticed some whiteflies in your grow room, you may want to bring temperatures down a little to fend off a bigger infestation (try to bring them down past 20ºC or 68ºF but be careful not to damage your plants).

Finally, make sure your grow room is well ventilated, an important step in fending off most garden pests.


Once you’ve addressed the environmental factors that might be contributing to your whitefly problem, it’s time to prune any infected leaves. Make sure to discard any prunings immediately to avoid infecting other plants.

You may want to try hosing down your plants. However, whitefly eggs are notoriously hard to remove from plants and might require a decent bit of water pressure which could damage your plants.

Next, we recommend you use some of the following techniques for removing whiteflies.



Ladybugs, lacewings and predatory mites prey on whiteflies and their eggs. If you haven’t already, we highly suggest introducing these insects into your grow environment as they’ll help you control a wide variety of pests (including spider mites).

We recommend starting with ladybugs. For more information on how to use ladybugs in your cannabis garden, click here.


If you’re not able to prevent or control a whitefly infestation using the above methods, you may want to try some of the following organic insecticides:

Essentria IC3: This product contains a generous mix of horticultural oils and can be directly applied to your plants without damaging them. Remember to apply it liberally with a mister, and to use it daily as it only remains active for roughly 8-12 hours.

Spinosad: All Spinosad products are completely organic We suggest spraying plants directly to kill any flies upon contact as well as adding some during water to help fend off whiteflies and other pests in the future.

Insecticidal soaps: These are great for spot-treating infected areas of your plants. Try not to get them directly on any buds and consider using them multiple times to ensure you’ve killed off all flies in your grow area.

Neem oil serves as a completely natural way to protect your cannabis plants against pests.

Is your cannabis grow affected by whiteflies? Click here to learn more about these common pests and how to control/prevent them.