When you inspect your cannabis plants and see bugs, the initial scare and worry is that you have a pest problem, but do not jump to conclusions! There is a good chance that what you see is a friendly predator, using your cannabis as a hunting ground thereby protecting it from pests.

The use of friendly predators is a good way for the organic cultivator to keep pests under control without having to use chemical pesticides. A lot of these beneficial predators will not pose any risk what so ever to your grow, and can be often bought and bred to act as a natural form of deterrence.

The following are a few examples of good, friendly predators that work well with your cannabis plants. It is not an exhaustive list, but one that should give you a good idea of what to look for and what benefits you stand to gain. It is also worth noting that these predators do not always work well together. For example, whilst not on this list, the introduction of a praying mantis to your grow would ensure that most types of larger pests would be eaten, but they will also eat all of the other predators present on your cannabis.

Beetles

Beetles are usually quite large and have blue, black, green or brown armored shells. They can fly, but are usually too large to navigate the cannabis plant themselves. They work best at ground level and will eat slugs, snail, cutworms and other lower based insects. Their habitats usually consist of damp places to hid, such as under bits of wood or in soil. A few of them can make a good addition to a “closed” greenhouse with adequate ventilation, as long as you give them somewhere to hide. Be careful not to step on them either!

Braconid Wasps

Whilst you are not likely to breed or maintain a colony of these, seeing one should not be a worry. This type of wasps lays its eggs within the bodies of other pests. When these eggs hatch, the larvae suck their victims dry, killing the pest in the process. They will “attack” and inject their eggs into such pests as aphids, scale and cutworms. You will know when a pest has been injected as it will start to develop a cocoon on its body, this has the larvae in it, feeding on the pest.

Bugs

There are a few species of bugs that are referred to as “true” bugs within the world of horticulture. Some of these are a gardener's, (and by extension cannabis growers), friend. These bugs find and feed off of pests, sucking them dry of their bodily fluids. Examples of these bugs are:

The assassin bug – These are quite large bugs that can vary in size between 10-25mm. They also vary in color, so it may be worth having a Google to see what they look like. They use a long, hard beak to repeatedly stab their victims to death, (hence the name), before sucking them dry. Assassin bugs will also use the bodies of their victims as an armor, placing them on their backs – a good example of this is ants. They will put multiple dead ants on their back to both offer protection and act as a warning. These guys will eat pretty much anything that moves of a similar or smaller size than themselves; they especially love spider mites, one of the most common pests found on marijuana plants. Note, assassin bugs will also quite happily suck the blood of large mammals, so be careful if you have them on your cannabis plants.

The big-eyed bug (a.k.a. Gercoris) – This bug is relatively small, with adults being 3mm in size. They have distinctively big eyes, hence their name. These little beauties are seen as a gardener's true friend and play a pivotal role in natural pest control. They will feed on aphids, spider mites, insect eggs, white fly and pretty much any other kind of small insect.

The Damsel Bug – This friendly predator is a medium sized bug, measuring between 8-12mm when fully grown. They use two powerful from legs to grab and hold onto their prey whilst they eat them alive. They will rid your cannabis of aphids, caterpillars and mites.

The Pirate Bug – Pirate bugs are tiny little bugs that will go after all of the aphids, thrips and spider mites on your plants.

Frogs

Small frogs will quite happily sit among your crop and eat any insects and flies that get too close. They can make a great addition to an outdoor grow if you have a garden or greenhouse near a pond.

Lacewing

These are quite large flying insects that grow to be about 2.5cm as adults. They develop huge transparent wings that stretch well beyond the reach of their long, thin and green bodies. They are pretty handy to have around and will eat the aphids and spider mites off your cannabis plants.

Ladybirds

This is a small type of beetle that most people will recognize on sight. They tend to have red shells with black spots on them, and a black head with white markings. They are extremely popular with organic cannabis cultivators, as they can be bought online and bred at home.

Their popularity stems from the fact that they are one of the best forms of natural pest control you can acquire. They will comb through your cannabis plants, ridding them of anything they can get their hands on. When deployed in large numbers they can be extremely effective. One ladybird can consume 4,000 aphids during their life time and produce 2,000 eggs, and the more they eat, the more eggs they lay. It may be worth acquainting yourself with how they look as larvae, as they look surprisingly malevolent considering what they turn into. Doing this will stop you mistaking the young for pests.

If you are planning to manually introduce predators to your grow, instead of just monitoring the ones that appear naturally, introduce these wonderful little soldiers – your crop will be well defended from other insects with these guys on patrol.

Spiders

Theoretically, spiders look like they should be a great predator for cannabis plants, but they are actually quite impractical. They are slow in their work, trapping flies and insects in their webs individually. They are also territorial and will attack other spiders that get too close. This means that they cannot keep up with the rate pests breed. The webs themselves are a bit problematic as well, you do not really want your plants covered in it when it comes to harvest.

One member of the arachnid family that can be of benefit are daddy long legs. These flying spiders do not produce webs and will actively hunt down smaller pests such as aphids and mites.