marijuana worms


Caterpillars are one of the most voracious and harmful pests that can affect our plants during the outdoor growing season.

It is a very aggressive pest that, if it is not controlled in time, will cause irreversible damage to our plants. But it can be identified, prevented and eradicated if we are fast and careful. As always, prevention and early detection is essential to avoid the serious damage that this pest will cause to our harvest.

  • 1 What are caterpillars?
  • 2 How to avoid the caterpillar attack.
  • 3 If prevention has not worked.
    • 3.1 1. Remove them manually:
    • 3.2 2. Biological control:
    • 3.3 3 To pulverize the plants:
  • 4 Watch out for outdoor crops.

What are caterpillars?

Caterpillars are the larvae of the lepidoptera family, which after their metamorphosis turn into butterflies (moth moths). There are more than 10,000 types of caterpillars but all are characterized by a long, segmented body, six legs and five pairs of pseudopaths with small hooks. They are polyphagous, so they feed on different types of plants.

The plague of caterpillars begins when butterflies and moths lay their eggs on our plants, so if we observe these animals hovering around our crop is a bad sign.

The life cycle of the caterpillar is very simple: once the eggs hatch, the caterpillars emerge, feeding on the leaves and flowers of our plants until they reach the right size to move on to the pupa phase. After 1 week to 1 month, the butterfly emerges.

The damage of the caterpillars is visible from the moment they hatch their eggs, since they feed without stopping, and we will be able to observe bites in our leaves and flowers. In addition, they have a predilection for flowering plants, which causes that their attacks favor the appearance of moulds and rottenness in the buds, a real disaster.

Caterpillars like to be hide in the underside of leaves and stems, so we must check and pay special attention to these parts of the plant, as well as the remains of the excrements that will be left behind.

How to avoid the caterpillar attack.

Obviously, the best thing we can do to avoid severe damage to the caterpillar is to prevent it, but how can we prevent it from appearing? Here are a few tips to help you avoid the caterpillar attack as much as possible:

  • 1. Constant and exhaustive revision of our culture to make an early detection, as well as to observe that we are not possessive butterflies and moths for our plants.
  • 2. Cultivate plants such as thyme or basil that repels them or cabbage or soybeans for which you have a predilection.
  • 3. Colocar trampas impregnadas de feromonas femeninas para atraer y atrapar a los machos e impedir que sigan reproduciéndose.
  • 4. Use Bacillus thuringiensis: bacteria that is used to treat caterpillar plague once we are already infested but can also be used as a preventative.

If prevention has not worked.

If prevention has not worked and we have this annoying plague in our crop, not everything is lost, although a quick detection will help a lot, as caterpillars are voracious devourers and will not stop eating until they reach pupa.

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The direct damage caused by this pest deriving from bites on leaves and buds, together with indirect damage caused by bites on buds that cause mould and rot, cause serious problems in our plant leading to death.

To treat caterpillar plague in our plants we can use one of these methods:

1. Remove them manually:

It may seem a bit rudimentary and even rather unpleasant but removing all the big caterpillars we can with our hands helps in eradicating this plague.

2. Biological control:

Biological control involves the controlled introduction of natural predators of the pest that we want to eradicate, so that they are responsible for eradicating it.

It is a totally ecological method in which you do not need to spray or water our plants with any product. The caterpillar’s natural predators are Coccinella septempunctata, commonly known as ladybird or Orius spp, a predatory bug of this type.

3 To pulverize the plants:

Spraying the plants with Bacillus thuringiensis, the same bacterium that we mentioned in the prevention section, is an effective anti-caterpillar remedy that we can use once we have been invaded by this pesky plague.

This bacterium penetrates the plant tissue that the caterpillar later ingests, causing irreversible damage to its digestive system as it contains toxic substances for the caterpillars.

Watch out for outdoor crops.

In short, we must be vigilant when growing outside crops for this type of pest that can quickly kill everything. We must use prevention methods and frequently observe our plants to make a quick detection and act as soon as possible by trying to get rid of the caterpillar before it kills our crop.

You may also be interested in these articles about the red spider mite or the Whitefly.

1 Comment

TINA VAIL 23 September, 2020, 6:48 pm

i just want to know how to get rid of and to kill the budworms.i have got the neem oil and it says it has bt in it

Caterpillars are one of the most voracious and harmful pests that can affect our plants during the outdoor growing season. It is a very aggressive pest

How to Keep Caterpillars Off Your Cannabis Plants

A healthy insect population contributes to healthy biodiversity in your garden. However, caterpillars can do some damage to your weed plants given the chance. This is how to deal with them.

Growing cannabis outdoors comes with many benefits: more space, bigger yields, the sun on your skin… However, these positives don’t come in isolation. Outdoor growers have to keep on their toes to prevent the local wildlife from feasting on their crop.

While aphids and whiteflies are some of the most infamous cannabis pests, caterpillars can do some damage too. Learn how to prevent and remove them below.


Caterpillars represent the larval stage in all moth and butterfly species, and researchers estimate there are over 175,000 species around the world.

These soft-bodied insects range anywhere from 1mm to 14cm in length. The majority of them are strictly herbivorous, except for a carnivorous and cannibalistic minority.

Caterpillars are differentiated from other larval species based on specific anatomy. Their key features include:

• Maximum of five pairs of legs
• Twelve stemmata (simple eyes)
• The presence of crochets on the prolegs (limbs that allow them to climb well)
• “Y” or “V” shaped cleavage lines on the front of the head

We rarely see the interesting behaviour of caterpillars with the naked eye, however, closer inspection reveals the fascinating world of these creatures—from their chemical defences to unique social behaviours such as forming alliances with ants.


At the very least, caterpillars will do some damage to your cannabis plants. A minor infestation will leave holes scattered throughout your fan leaves, and a larger problem can lead to fatal damage that cannot be remedied.

Of the thousands of caterpillar species, a select few are more frequently problematic to cannabis growers. The cabbage looper [1] , for example, prefers to graze on the surface of fan leaves, using its siphoning mouthparts to strip away pieces of tender tissue.

Other species go directly to other parts of the plant’s anatomy, such as the stems. If this major structural component becomes compromised, a plant may never recover. For these reasons, you should constantly be on the lookout for caterpillars, ready to remove them from your growing space.


A caterpillar infestation can range from a few inconvenient holes in foliage to total devastation of a specimen and subsequent loss of yield. Regardless of the severity, these hungry critters always leave some of the below symptoms in their wake.

Irregular holes: Caterpillars will chomp your leaves, but they won’t be neat about it! They’ll leave oddly shaped holes in your fan leaves that range in size from several millimetres to several centimetres across.

Stem damage: Species such as the Eurasian hemp borer bypass the leaves and decide to feast on the denser material found in the stems and branches. They make a hole in the surface of the tissue and bore through the interior of the structure.

Chewed flowers: Borer species will also have a go at your flowers—a heartbreaking sight for any grower to endure. They’ll burrow into your buds and relish in the supply of resin and precious phytochemicals. They primarily aim for the base of developing buds, resulting in wilting and death of the flower.

Leaf yellowing: Damage to your plants—particularly the stems—can affect water and nutrient transportation. Leaves located above the point of damage will likely begin to yellow due to a lack of these vital components.

Stunted growth: Chances are you’ll have noticed the infestation by the time you realise your plants are becoming stunted. Caterpillar damage can stress plants out, reducing their size and productivity.


Although they have the potential to do some real damage, caterpillars are relatively easy to get rid of. Many conventional gardeners reach for a bottle of pesticide as a solution, but most cannabis growers aren’t keen on spraying their plants and living soil with noxious chemicals.

Fortunately, there are numerous natural and organic means of putting an end to a roaming caterpillar horde in your garden. Here are the easiest ways.

Physical removal: Caterpillars are perfectly visible to the naked eye. Unlike aphids, they are easy to spot. If you’re only dealing with a handful of specimens, simply pick them up, place them in a jar, and relocate them to a nearby natural setting. Many species are nocturnal, so prepare yourself for some nighttime hunting.

Parasitic wasps: Why spend potential hours picking caterpillars from your crop when your own army of beneficial insects can do the job for you? Parasitic wasps prey on caterpillars and use their bodies to lay their eggs. Although the means of dispatch is nothing short of horrific, nature has engineered this species to take down caterpillars.

Praying mantises: Masters of stealth, these cool-headed assassins wait patiently underneath leaves, hidden in flowers, and behind stems until their prey makes the first move. These brutal yet swift predatory insects do an effective job at reducing caterpillar populations.

Bacterial sprays: These natural pesticides contain bacterial species that harm caterpillars, without posing a risk to cannabis plants or the people that smoke them. Avoid administering these sprays too close to harvest time. Formulas containing Bacillus thuringiensis will do the trick.


As the age-old adage goes: Prevention is better than cure. You can take certain measures to avoid infestations taking hold in the first place, saving you time, effort, and damaged plants.

Beneficial insects: Introducing insects as a preventive measure will minimise the risk of infestation. Add these patrolling insects before you even transplant outdoors to allow them to build a substantial population.

Barrier fabrics: They might not look pretty, but they are effective. Set up a wooden frame and fabric layer around your crop to prevent caterpillars from physically reaching them to feast and lay eggs.

Neem oil: Derived from a South Asian tree, neem oil serves as a natural pesticide. It contains phytochemicals that deter insects when administered as a soil drench or foliar spray.

Caterpillars might be fascinating—some even cute—but they'll eat your plants to the roots if they get a foothold. Learn how to defend against them.