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Most Common Pests Found on Cannabis

Updated: Jul 13, 2023


Written by: Madelynn Gevaert / February 3 2023

There are many pests that can be found on cannabis, this article will review the most common pests that attack cannabis and how to control and get rid of them.


Aphids

Aphids are a very common garden pest, these tiny insects have a large variety of species and are described as a small, see through and soft bodied insects with long antennae. These insects can be found in many different colours including green, red, black, yellow and white,


How do Aphids Affect my plant?

Aphids can pose a serious threat to any garden, stunting plant growth, transmitting diseases, causing deformations on the plant, and can produce plant galls. Aphids cause damage to plants by sucking sap from parts of your plant like stems, leaves and even roots. As they are sucking this sap, they produce a substance called honeydew which is left on leaves, this in turn will attract other insects like ants – which is not good either.


How do I get rid of Aphids?

To begin eradicating Aphids, you can start by pruning off any parts of the plant where you can see a colony. If you have a large amount of Aphids you can try using biological predators, like a lady beetle and they will eat the aphids. Another option would be with insecticides, like Safer’s End-All

for people who are looking for a cleaner way to get rid of aphids without any harsh chemicals. Aside from that would be chemical insecticides, which a pesticide license is needed for.


Fungus Gnats

These tiny, about the size of a fruit fly pest are most commonly found indoors. Fungus gnats are attracted to moist potting soil, laying about 200 eggs (per gnat) on any type of organic material on the surface of the soil. Then about 3 days later, the eggs hatch into a larvae and dive deep into the soil to eat fungi and dead plant matter.


How do Fungus Gnats affect my plant?

Primarily, Fungus Gnats affect your plant through their larvae, as mentioned previously and will eat fungi and decaying plant matter, the adult Fungus gnats can also carry diseases and pass them along to your plants as well.


How Do I Get Rid Of Fungus Gnats?

If you suspect the infestation is not so large, you may be able to find where they are breeding and make it so that they can’t by changing the environment needed for them, you can let the soil dry out about 2 inches on top, and add up sticky traps to attract the pests to those, trapping them on the sticky glue (check out our Koppert Sticky Traps ). Another effective way of removal is through insecticides containing Pyrethrum like our “ Doktor Doom Total Release Fogger”



Spider Mites

Being one of the most commonly found plant pests, Spider Mites are almost too small to see, these bugs have an oval body with 4 legs and can be a variety of colours. Living on the underside of leaves, these pests rapidly increase in population as these eggs laid can produce thousands baby mites on just one leaf.


How do Spider Mites Affect My Plant?

These small pests are sap sucking and cause significant damage to plants. Feeding on the underside of leaves, these pests can also leave your plant vulnerable to other pests and attracting them, will only make things worse. Once a large enough colony has taken place, they will make a very fine spider web looking netting that helps protect them from predators.


How Do I Get Rid Of Spider Mites?

There are many ways to go about getting rid of spider mites. You can try mixing 1 part rubbing alcohol to 4 parts of water and using that as a foliar spray, this will help to dry out the mites and kill them, to make sure your plant wont be negatively affected by this solution, try doing a sample leaf to see how it will react. Another great way to get rid of these pests is with biological predators, and is an organic way of doing so also, insects like ladybugs and lacewings can be of great help when dealing with a large amount. Lastly you can use insecticides and pesticides, not all of them being filled with harsh chemicals like products from Safer’s Brand like "Insecticidal Soap” or try out Ortho “ Bug B Gon Eco” which contains canola oil.



Leaf Miners


Leaf miners is a term used to describe larvae from 3 different species. All of these species live inside the leaves of plants, feeding on them until they are fully grown. This can infect your plant with the spread of diseases and stunt its growth.



How Do Leaf Miners Affect My Plant?

You can easily spot a leaf miner infestation by the squiggly trail they leave behind after eating their way through the leaves. Most often the plant can remain healthy, unless there is considerable damage, this could result in the loss of a great amount of leaves and foliage. The tunnels the leaf miners make are also susceptible to diseases.


How Do I Get Rid Of Leaf Miners?

To get rid of leaf miners you can go about it a few different ways, the easiest being to remove all affected leaves and inspect your plant to see if you can find the culprit. Insecticides and pesticides are another good way of getting rid of leaf miners, safer sprays like Safer’s “Trounce”, sprays are not always effective because the larvae are in the leaves however they aid in killing off the adult bugs. Mostly just keep an eye on the plant and remove infected leaves.


Thrips

These hard to see insects can become quite problematic as the first sight of them will be a plant that looks like it has a disease or isn’t getting its proper nutrients. These pests attack a large variety of plants and can be quite hard to get rid of. When looking at a thrip under a microscope, they are usually yellow, black or brown in colour, and have very narrow skinny bodies.


How Do Thrips Affect My Plant?

Thrips will typically attack newer plant growth, or parts of the plant closest to the stem to avoid the elements of outside and be protected whilst feeding. You will be able to tell if a thrip has attacked your plant by the silver-white looking spots that are left behind. Thrips can also cause your plant to stunt in its growth and can spread diseases.


How Do I Get Rid Of Thrips?

A good start to removing thrips would be to shake the branches with a paper or cloth underneath to catch them pruning off affected leaves. Another method would be to use sticky traps and place those next to your plants or hanging from the branches. You can also try using pesticides and insecticides like Bug B Gon with use of its pyrethrin will work effectively. Diatomaceous Earth is another great way to fight against thrips as the small powder is very sharp to soft bodied insects and will cut into them.




Leafhoppers

Leaf Hoppers are about the size of a grain of rice and can be seen very easily, and are a variety of colours, ranging from green, yellow, brown to even blue and red. These bugs can reproduce rapidly in the correct season, female leaf hoppers can lay up to 6 eggs a day.


How Do Leaf Hoppers Affect My Plant?

Leafhoppers feed off sap from plant leaves, leaving small white spots on leaves, sometimes even looking translucent. As these bugs feed they leave a secretion called honeydew just like Aphids do, attracting ants and other pests who will only help them survive longer. While These pests can carry many types of diseases and bacteria.


How Do I Get Rid Of Leaf Hoppers?

First start off by removing affected leaves, to help prevent the spread of diseases that these bugs can carry. To dispose of affected waste after pruning throw them away so spores and other bacteria are not able to continue to spread. As mentioned previously with thrips, diatomaceous earth is a great way of combatting these soft bodied pests, you can take this powder and sprinkle it around your plant.


Thanks for reading and we hope that this guide helped you to get rid of these annoying pests!

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