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Home » Insects and Cannabis: The Good & The Bad

Insects and Cannabis: The Good & The Bad

Whether indoors or outs, there is one thing every gardener and farmer dreads the most.: insects in your garden, munching on those beautiful green leaves you’ve worked hard to grow. Let’s talk insects and cannabis.

Here, we’ll show you what insects are harmful to your plants and which are good. Not only that but how to prevent a possible breakout to stopping one altogether.

Identifying the Enemy!

When growing cannabis, any plant for that matter, you want to know what you are looking for if you are starting to see damage on your plants.

There are several common types of insect families to look out for. These 6 are the top insects that almost every gardener may have to deal with. And each is a pain in its own right.

Spider Mites

The spider mite is probably the most common and annoying insect. If you see them before they spin their webs of horror, they look like little red or orange dots moving around on your plants. If your plant is in flower, that’s the worst time to get them. They will go straight to the flowers and start spinning webs like they own the place. Last I checked, we don’t put rental signs up on our plants.

cannabis insects


Aphids look like little green and orange eggs. They suck on the sap of your plants and breed quickly, hanging on the plant’s stalks, stems and branches. 

Aphids suck for two reasons, not only will their larva eat your leaves and your flowers, but they will also fly around and in your face when you least expect them to. 

The adults look like little black dots with large white wings. If you see them, you will want to look under your leaves. If you see it peppered with tiny yellow and white balls, that’s their eggs. These guys are a rapid producer, and the larvae can take down a plant in a day if the conditions are right.

Aphids will burrow a hole into the leaf, not the stalk, but the leaf. Then they tunnel their way through the leaf, leaving an unsightly trail on your leaves, laying their eggs inside the plant. 

Rude, right?


Thrips look very similar to the springtail, only bigger and not white. Like the Leaf Miner, they leave an unsightly mess on your leaves. This is their tell tail sign that you have thrips, is if you see silver spots starting to form on your leaves. Once they are there, they are a pain to get rid of, so make sure you keep a close eye out for these little guys.

cannabis insects

Fungus Gnats

These pests are more of a physical annoyance than one that would immediately harm your plants. Fungus gnats as larvae live primarily in soil. If not put into check, they can build up enough larvae to start eating at your roots, similarly for adults. 

If enough of them are allowed to mature, they can start attacking your plants. But they become more of a nuisance when they begin to fly in your face, ears, nose, and mouth. They look like tiny black flies, looking similar to the fruit fly. Thankfully, though, these guys can be easy to handle and get under control.

How to Win the War with Insecticides

When it comes to an outbreak, sometimes you need something that will work immediately. Chemical pesticides are a great product, though they are not recommended for organic growers and farmers. 

These chemicals are almost like a blanket product, where they will kill the insects within that family, regardless of whether it’s beneficial or not. 

They’re used for their effectiveness and ability to stop an infestation dead in its tracks. Be very cautious when using these. You will want to follow their directions to the tee, and NEVER spray your flowers with chemicals, only the foliage. This will prevent you from either getting sick or poisoning yourself. Also, read the MSDS data for that particular product, as well. 

But what if you don’t want to use chemicals?

Natural insecticides tend to use more of what nature provided us, and we isolate what works. And that’s both bacteria and fungus. These are much safer to use since there are technically no chemicals. You will still need to follow the directions and warning labels. It may be safe to use on the plant, but direct ingestion can put you into a tizzy for sure. 

These are also great for your IPM; since bacteria and fungus are living organisms, they will stay on your plant longer and help deter the harmful insects from even trying to chomp down on your plants. It’s almost like putting a shield around your leaves. The bacteria and fungus can also help feed your plant since they would have a secondary function to help keep the plant happy and healthy so they can eat.

Fighting Fire with Fire!

All chemicals bring their risks, so why not even the odds?

An added benefit to predatory insects is that they don’t mess with the plants negatively, even if they get hungry. 

Predatory Mites

Predatory spider mites look just like their greedy cousins. The only difference is that they don’t spin webs on your plants. Living mainly in the soil, these guys will hunt out other spider mites, thrips, and aphids lingering around your plants. 

cannabis insects

Most predatory spider mites can establish themselves in your pots quite easily. That’s why they are great, not only as an IPM measure but to stop an infestation. If they get hungry and there are no other insects to munch on, they either turn cannibalistic or start to eat decaying matter.

Rove Beetles

These predators live by their name. If you have multiple pots and you inoculate just one of the pots, within days, you will start to see them in other pots too. 

These guys will set up shop fast and spread like wildfire. Like the spider mites, they will also use cannibalism to sustain their numbers. They also help keep the soil from compacting as well.


The ladybug is an integral part of our ecosystem. For one, they develop a voracious appetite straight from birth. Their favourite meals are aphids but will be more than happy to chomp down on most other forms of non-beneficial insects. They aren’t too picky. 

The fun thing about these guys is you can build them a home to live in, so you won’t have to worry about getting more. All you need to do is leave out a little water for them to drink, and you’re good to go. 

cannabis insects

They will take care of an outbreak nearly overnight. We also need more of these guys, so if you order them, build them a home they can live in for a while and an inviting environment with plenty of flowers they love to frequent in the wild.

Assassin Bugs

These guys don’t reproduce quickly like many others on this list. So, you would not want to get these bugs if there’s an outbreak. But, once they have established themselves, they are near impossible to get rid of (not that you’d want to). 

cannabis insects

Assassin bugs feed on almost all types of non-beneficial insects. They inject their mouths into their victims and suck them dry. This sounds gruesome, but there’s a reason. They will “bite” you with this same mouth, and it’s painful like a bee sting. There is only one in this family you don’t want to run across, though. It’s the kissing bug. These guys are known to carry parasites. But these aren’t too common.

Create a Good Integrated Pest Management System

Knowing how to identify, manage and remove pests is great, but it’s always nice not to have to worry about them in the first place. 

When you get ready to grow, the first thing you should want to have is a clean work area. This will prevent them from finding a home to establish themselves. 

Then you will want to maintain that growing area properly. The more you keep on top of keeping your space tidy, the harder it will be for those nasties to come in and wreak havoc on your crops.

You then want a good preventative measure for your plants as well. Weekly, monthly, and annual spraying and soil soaks will help a lot. The biggest part of this is ensuring that you don’t use chemicals and insecticides that will kill off your beneficial microsystem if you grow in an organic setting. 

You can even use this in tandem with beneficial insects. The insects will be your physical line of defence, as where the sprays and soaks will be if the front line gets breached, you’ll have something shielding your plant. It’s highly recommended to combine what you can when setting up a good IPM.

Finally, you will want to clean your grow space after each grow cycle thoroughly. Just because you didn’t have an issue with a particular insect doesn’t mean there could be that one lying in wait for that perfect opportunity to go after your crops. 

Cleaning will get rid of them once and for all, giving you the peace of mind that you won’t have anything you don’t want in your grow space.

Insects and Cannabis: Conclusion

It’s great fun to grow plants and quite therapeutic. Whether inside or not, there’s always that one thing that annoys the gardener. That’s having bugs come and eat away all that hard work. 

But, when using a combination of insecticides, insects, and the environment, you can prevent an outbreak from happening altogether.

Hopefully, you got something beneficial out of this. So, remember, happy growing, and stay lifted!

Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

This post is also available in: French

Chris Staniszewski