Most Common Pests In Cannabis: Broad Mites

Broad mites are microscopic bugs that feed on the content of your cannabis plants, necrotizing the newer plant growth.
11 August 2020
5 min read
Most Common Pests In Cannabis: Broad Mites

  • 1. What are broad mites?
  • 2. What do broad mites look like?
  • 3. Where are broad mites found?
  • 4. What do broad mites do?
  • 5. Broad mites symptoms
  • 6. How to prevent them?
  • 7. How to deal with them?
  • 8. In conclusion

Broad mites are extremely small bugs that can attack your crops and even though they weren’t as common as other pests in cannabis, their appearance in cannabis crops indoors and outdoors has increased lately, as cannabis becomes legalized and more popular.

1. What are broad mites?

Broad mites are scientifically known as Polyphagotarsonemus latus, they occur mainly in temperate climates and can attack a wide range of plants, from vegetables to fruits to ornamental plants but it wasn’t common to see them on cannabis crops until cannabis became more popular and growing cannabis more and more legalized.

These microscopic species of mites are found especially in fruit crops but also affect cannabis plants. They feed on your plant, leaving behind their toxic saliva, and because they're tiny, it's super hard to spot and deal with them.


2. What do Broad mites look like?

Broad mites belong to the family of mites, just like spider mites and russet mites they have four pairs of legs, a medium-sized mandible and they’re of a yellowish-white with white hairs on their body but are considerably smaller, unlike other mites, broad mites are almost imperceptible to the naked eye so you need a microscope to identify them.


Broad mites: appearance

Broad mites look similar to other mites but cannot be seen with the naked eye.

Without special equipment, you’ll only be able to spot them once their population has grown too much and you can see the egg clusters throughout your plant, we recommend being 100% certain of the type of mite you have before starting the treatment. 

Cannabis plants can suffer from three different mites, here's a table to help you identify them properly.


 Broad MitesRusset MitesSpider Mites
ColorBrown, yellow or whiteMilky-white, beige or yellowReddish-brown or greenish-yellow
AppearanceOval-shaped with 6 legsElongated with 4 legsRounded with 8 legs

Different types of mites and their differences.

Just make sure you don't mistake broad mites for russet or spider mites, even though these bugs look similar and the symptoms look practically the same, it's essential you identify them before starting the treatment.

3. Where are broad mites found?

Because of their tiny size, broad mites can hide in the crevices of the branches and besides the “veins” of the leaves, but they prefer the newer growth to lay their eggs so if you suspect they’re attacking your plants, you will most likely spot them on the underside of the new leaves and branches.


Broad mites: where are they found

You will need to use a loupe or a microscope to discover broad mites on your plant.

Be 100% sure you're dealing with broad mites before starting treating your cannabis plants. Broad mites are microscopic so you need a loupe or a microscope to be able to start and deal with them before the infestation gets out of control.

It's worth to invest in a tool to identify a broad mite infestation early, before it gets out of control.

4. What do Broad mites do?

Even though mites are a source of infections, the main damage comes from their bites1.

Broad mites suck out the nutrients from the leaves and branches which inhibits photosynthesis and also drain all other liquids from the plants, stunting growth and ultimately killing the leaves and every other affected part.


Broad mites: symptoms

When your plants are suffering from broad mites the leaves will develop a shiny and wet appearance.

These insects also leave their saliva behind, these wet spots combined with the damage from their bites can cause easily serious diseases and the appearance of fungi.

5. Broad mites symptoms

Because these bugs are super hard to see with the naked eye, you can easily confuse the symptoms for:

There are a couple of ways to know what’s really going on.

The first sign that can guide you into knowing if your plants are being attacked by broad mites is if the affected plant growth is the newer one, broad mites prefer new plant growth to lay their eggs and feed on so if you see the top part of your plant has a wet look, the new leaves are growing twisted or you see yellow spots on the top leaves, it’s most likely because you have broad mites.


Broad mites: signs of infection

If the broad mites infection is serious, the leaves will curl, brown and start to die.

Also, as the infection progresses, you will see the leaves starting to curl up and the leaves browning and the tips dying, if your plant is already flowering and the mites attack the buds, you’ll see them turning brown and dying, so it’s essential to take action as soon as you see early symptoms.


6. How to prevent them?

Preventing broad mites can be hard because they can come with animals, with the wind or infected clones.

If you think you can suffer from this mites, you’ll have to spray regularly with neem oil or a pesticide of your choice, have in mind that spraying your plants regularly can stress your plants so it’s better to do it with organic products and if you are sure they can attack your plants.

7. How to deal with them?

If you’re already suffering from a broad mite infection, it’s essential you take action immediately.

The first thing you should do after identifying2 you have these mites on your plants is removing the infected parts, this will reduce the population and prevent it from spreading to the rest of the plant and to the other plants around.

After removing the infected parts of your plant, you’ll have to start a treatment, you will have to spray with insecticidal products up to 3-4 times a week or even daily, depending on the gravity of the infestation, remember that spraying with the lights on can burn your plants so it’s better to do it when the lights are turned off.


Broad mites: how to deal

To be sure you're dealing with mites it's better to use a microscope or a loupe to spot them before starting treating.

Even if you think you have completely eliminated them, continue spraying for 4-5 weeks more, this will prevent them from coming back, it’s crucial they don’t come back because the second time they’ll be resistant to the product you’ve been using and you have to buy another one and this can have a toll on your plant so after you’re 100% sure you’ve taken care of them all continue the treatment for up to a month after they’re gone.


8. In conclusion

Broad mites are just like every other mite but due to their microscopic size, it can be extremely hard to spot them without the proper equipment if you see the newer plant growth developing with yellow spots or with deformed leaves, make sure you take the actions needed as soon as possible.

If you have tips or tricks to help fellow growers get rid of broad mites, please leave us a comment below!

External References:

  1. Broad Mite Effects on Chili Shoot Damage and Yields - Vichitbandha, Patchanee & Chandrapatya, Angsumarn. (2011).
  2. Control of The Broad Mite On Bell Pepper, Spring 2005 - Schuster, D. (2006).
11 August 2020