Insects And Creepy Crawlies

Ant Baits

Ants on your marijuana plants are a sign of pests that excrete ‘honeydew’. While the ants themselves pose no real threat, they are an indication of the presence of aphids.

When you rid your plants of aphids or any other honeydew excreting insect, you will diminish the ant population.

You can always buy ant baits, available wherever your shop or you can make your own repellents with items you have in the kitchen:

  • Sprinkle ground cinnamon around your plants at soil level. Ants do not like the smell and will not cross the barrier.
  • Apply food grade diatomaceous earth to the ant mounds, available at garden centers. This is an extermination method safe for pets and animals but will kill other pests, such as fleas, chiggers, ticks and other crawling insects.
  • Plant catnip in the garden. Ants hate it however you may attract cats to the garden. Cats won’t hurt your cannabis unless they pee on them.
  • Plant spearmint in the garden. Ants hate this as well.

Aphid Midges

Aphid Midges
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Aphidoletes aphidimyza is a small fly resembling a tiny mosquito. Purchase the pupae online from a beneficial organism supplier, such as Planet Natural, Hydro-Gardens, Ecosolutions, etc.

They arrive in a bed of moist soil. Spread the mixture around the base of affected cannabis.

Aphid midge larvae need approximately seven aphids to complete its growth cycle. The larvae then mature, the adults lay eggs and the killing cycle continues.

Bacillus Thuringiensis

This is a naturally occurring soil dwelling bacterium. It is beneficial in targeting leaf eating insects; among them are caterpillars and fungus gnat larvae.

The bacteria react with the stomach cells of the pests rendering them unable to eat. They literally starve to death!

Various strains of bacillus thuringiensis target different leaf eating pests. Read the label to ensure you are buying the proper product.

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Follow directions and this treatment will not only kill, but inhibit re-infestation. Used properly, this control won’t harm pets.

Some of the more popular brands are Thuricide, Gnatrol and Teknar. Consult the internet for the solution to eradicating your particular leaf eaters.

Beauveria Bassiana – Beneficial Fungi

Beauveria Bassiana – Beneficial Fungi
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Beauveria bassiana is a naturally occurring fungus found in soil. It is a parasite that favors termites, thrips, whiteflies, aphids and some beetles, causing white muscardine disease in its targets.

This means the spores penetrate the pests, germinate and grow inside the host, killing it within days. Beauveria bassiana is also an effective control against fire ants, stem borers, caterpillars and mites.

As you see, this is a good fungus to keep around in protecting Mary Jane from unsuspecting attacks. Animals and humans are not affected. Check the internet for available sources.

Boric Acid

Boric acid is effective for combating the onslaught of ants, termites and cockroaches.

It has been used as an insecticide since the 1930’s and has a low toxicity level for humans and animals.

Although extremely effective, it washes away with water. To counteract this, it is necessary to re-apply after rains until the pests are gone.

Boric acid can be purchased at hardware stores and supermarkets. Look for it in the pesticide sections.

Sprinkle the powder around the areas where the targeted pests are present.

As a safer solution, make a bait and place throughout the garden. Here’s one suggestion: dissolve one teaspoon boric acid and six tablespoons of sugar in two cups water.

Prepare a plastic container with a lid by boring several holes in the body of the container. Soak several cotton balls in the boric acid solution and drop into the holes.

Cover and place the containers throughout the garden. Clean and repeat weekly until there is no more evidence of the critters homesteading in your marijuana patch.


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Capsaicin is a component of hot peppers. In addition to the heat it provides our foods, its Mother Nature’s way of naturally protecting the pepper plants from insects and other critters who might be tempted to munch. 

Spider mites, aphids, whiteflies, thrips, even deer, squirrel and rabbits are repelled by the capsaicin in peppers.

Consider planting hot peppers in Mary Jane’s garden to naturally repel these nemeses without spraying a control.

If you’d rather spray, you can make your own concoction or purchase commercially marketed products at any garden center.

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For homemade pepper spray, add two tablespoons ground red pepper to one gallon water and soak overnight.

Add six drops castile soap (do not use an antibacterial soap), shake to blend and pour into a spray bottle.

To use fresh peppers, substitute the ground red pepper with one half pound chopped hot peppers.

Spray your marijuana plants thoroughly wearing goggles and gloves, as the pepper will burn your eyes and skin if not well protected.

Carbon Dioxide

In marijuana grow rooms and greenhouses raising the level of carbon dioxide, which is necessary for photosynthesis, can kill spider mites, whiteflies, aphids and thrips in addition to increasing plant growth and quality.

Raising the natural level of 300-400 ppm to 10,000 ppm can be achieved by applying carbon dioxide boosters and holding the raised level for an hour.

Available online or at garden centers, various application methods are there for whichever you feel most comfortable.

Take care to thoroughly ventilate the area after treatment so as to not become asphyxiated.

Carbon dioxide can also be a deterrent against ants, moles and gophers in your outdoor marijuana garden.

By dropping eight to sixteen ounces of dry ice into the rodents’ entry point, moles and gophers will become engulfed in the gas and either die or move elsewhere.

To combat ants, pour one gallon seltzer water into the anthill.

Cream of Tartar

Don’t you just love the natural options to combating nature’s attack on beloved Mary Jane?

Cream of tarter, found in kitchens of those of you who cook from scratch, can be sprinkled along doorways and baseboards; anywhere ants may enter the home.

This is useful for indoor marijuana grow rooms, whether container or hydroponic.

Again, the best defense against ants is to rid your cannabis plants of honeydew excreting insects as discussed earlier in this book.

Diatomaceous Earth

Diatomaceous Earth
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This is soil that contains teeny tiny shell remnants of sea creatures. They are sharp as glass to creatures such as snails, fungus gnat larvae and thrips larvae.

The tiny shards piece soft buggers, severing their glands, leading to imminent death.

Diatomaceous earth will not harm humans, as the fragments are minute, but they mean ultimate death to the soft squishy varmints that attack your cannabis garden or any garden meant for consumption, for that matter.

Diatomaceous earth is available at most garden centers. Follow label directions for the appropriate applications for ants, slugs and snails, fungus gnat larvae and thrips pupae.

Iron Phosphate

This, in addition to beer, is one of the most effective forms of eliminating snails and slugs from chomping on Mary Jane’s beautiful leaves.

Simply sprinkle it sparingly around your cannabis garden; no need to ‘bunch’ it up.

Iron phosphate is resilient to rains (which is when snails attack, as they thrive in wet soil) so you only need to re-apply every couple of weeks.

During the months of March and April, you may want to be a little more diligent with applications every ten days. This is when slugs pro-create, if you will.


You may have noticed the lacewing and wondered what you are seeing. Lacewings look like small green flies with delicate wings.

You surely have seen them around your garden. Adults feed on nectar, pollen and aphid honeydew, which is good news for Mary Jane!

Be careful when identifying this welcome guest in its early stages of life; it may resemble a caterpillar, but has the face of an alligator. If you have Wally Gator in your garden, you want to make him feel most welcome!

Due to the indiscriminate diet of the lacewing, they are not recommended for indoor marijuana grow rooms.

Lady Beetles or Ladybugs

Lady Beetles or Ladybugs
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Ladybugs are those pretty little bugs you tend to coax towards your hands. And that’s ok, because they are perfectly safe for humans and animals.

They are not interested in feeding on you; you don’t have what sustains them. As pretty as they are, ladybugs will eat up to 60 aphids per day.

Ewww, but good for you and Mary Jane! Ladybugs have a voracious appetite! They also dine on scale, mealy bugs, leaf hoppers, mites and several ‘soft’ insects.

If you don’t already have ladybugs in your garden, they are available for purchase online. It is recommended to keep them in the fridge until early evening or early morning.

Releasing them in the heat of the day or when the sun is up will cause them to leave their new home.

Water the area before releasing them so they can have a drink and become accustomed to their new surroundings.

Ladybugs do not fly at night, so this is the perfect time to let them become comfortable and to discover the feast you’ve provided for them.

Ladybugs can live up to three years and will protect your cannabis plants from many insects.

Minute Pirate Bugs

Most commonly found in agricultural crops, these little buggers are natural predators to aphids, mealy bugs, spider mites, small caterpillars, scale and thrips.

They pierce their prey with sharp little beaks and suck them dry. When minute pirate bugs run out of prey, they feed on pollen and plant juices.

When ordering these predators from insectaries, they are shipped in bran, rice hulls or vermiculite. Shaking them loose onto your marijauna plants sets them free and puts them to work!

Parasitoid Wasps

These tiny wasps are parasitic only to garden pests; they do not sting people or animals. They lay their eggs in larvae, eggs and even some adult pests.

The wasps then proceed to devour the damaging insects from the inside out. They feast on arthropods, which are invertebrate animals.

Parasitoid wasps usually go unseen but are an excellent biological control for aphids and caterpillars.

Predatory Mites

Predatory Mites
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Predatory mites will attack fungus gnats, spider mites and thrips. They breed rapidly indoors, so this is a good natural control for your indoor grown cannabis plants.

Predatory mites are available online, purchased as adults. One hundred mites will control approximately twenty five square feet in the marijuana garden.

Predatory Nematodes

These microscopic creatures live in the soil, attacking soil dwelling larvae of fungus gnats and thrips.

They are also a good control for other pests having a life stage in the soil such as beetles, borers, crickets, and certain flies, moths, cut worms, meal worms, chinch bugs and yellow fever mosquitoes. Predatory nematodes are available for purchase online.


Pyrethrum is a small white daisy derived from the chrysanthemum family.

Having a low toxicity level to humans and animals, pyrethrum and insecticides made from nature’s bug blaster are effective for the control of aphids, whitefly, potato beetle, flea beetle, ants, caterpillars, fungus gnats, leaf miners, mealy bugs, scale spider mites, thrips and cabbage worms.

It is important to note pyrethrum is toxic to fish and many beneficial insects. Follow directions when using a commercially produced formula.


Rotenone is extracted from the roots of plants in the pea family.

It is considered a botanical insecticide. Botanical insecticides break down into harmless compounds when exposed to the sun, which means there is no residual toxic effect to the garden.

This is good for marijuana plants however it is toxic to fish, so keep it away from fish ponds or aquariums.

Birds can also be affected after coming in contact with rotenone; use caution if you choose this method of control.

Insecticides containing rotenone are effective on beetles and caterpillars and other leaf demolishing pests. Due to its harmful effect on critters you may not want to affect, read labels carefully.

Saccharopolyspora Spinosa – Beneficial Bacteria

Saccharopolyspora Spinosa – Beneficial Bacteria
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Well, there’s a mouthful! This species of bacteria wasn’t discovered until 1975. Commonly called spinosad, it occurs in the soil.

Spinosad became registered in the United States as a pesticide in 1997. It has low toxicity to humans and pets and has recently been used to treat fleas in dogs and cats.

As a control for cannabis and other plants, spinosad is effective in the elimination of caterpillars, thrips, leaf miners, borers, fruit flies, spider mites and aphids.

It does not affect beneficial insects, making it a formidable foe against damaging pests.

Spinosad is the product of waste created by the Saccharopolyspora Spinosa.

It is water soluble meaning it breaks down in soil or on leaf surfaces, therefore poses no threat to ground water. For this reason, it has been deemed safe for organic farming and gardening.


Applied on marijuana as a spray, insecticidal soaps are widely used to control soft-bellied insects.

Aphids, whiteflies, mealy bugs, scale, spider mites and thrips become dehydrated when they come in contact.

By adding one to two tablespoons of castile soap to a quart of water, you can avoid purchasing commercially available products.

The next article will cover controls that are effective in combating both insects and disease.

Many of the aforementioned will serve the same purpose; do your homework before applying any control to ensure proper usage for whatever ails Mary Jane.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible.


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