Most outdoor- and guerilla growers experienced the terrible feeling you get when ripping out pest-infected plants. This is almost as heart-breaking as loosing buds to mould. It’s a sad thing to sacrifice the already infected plants to be able to harvest at least something. It doesn’t necessarily have to be that way. There are different approaches of keeping the vicious caterpillar away from your precious plants.

Know Your Enemy

It’s extremely important to know what exact species is threatening your harvests. Individual strategies that are specifically tailored to the pests are the most effective. When having problems with caterpillars, the analysis can be quite difficult because there are more than 21.000 different species.

All of them are the larvae of butterflies, or moths. They have one thing in common: They all love cannabis, just like us.

The Corn Borer and the Hemp Borer are causing the greatest damage to cannabis plants and therefore are examined in further detail. Attacks of the Hemp Borer are very problematic because they feast on the marrow within the stalk of our plants.

This ultimately leads to a weakening of the whole organism. It only takes a handful of larvae to destroy an entire plant within a short period of time. Corn Borers are equally damaging because they drill holes into the stems and therefore open up the gates for all kinds of sap sucking bugs.

How to Spot Caterpillars

Spotting stem boring caterpillars on time is the most important thing in order to have a decent chance to get rid of them. This can be tricky because caterpillars are true experts of camouflaging, and eggs are kind of hard to spot.

When you are checking your outdoor grow, closely take a look at all the stems of your plants, to detect holes, with brown trails surrounding them. If you find these holes in your stems, the chances are pretty high that you have a serious problem. The only thing you can do at this point is to remove all the parts of the plant, where you have found these holes.

The best thing to do, when problems with stem boring caterpillars occurred in the past, is to be one step ahead, preventing the eggs of butterflies to hatch, and the larvae to consider your plants as a potential nourishment.

Butterflies usually lay their eggs on leaves, so the newly born caterpillars have something to eat after they hatch. Oftentimes, butterflies prefer to lay their eggs in the higher parts of the plant. This is where you have to look for them. These eggs are tiny, but you can use a magnifying glass, or the pocket microscope, every grower should have. The eggs look like a small cluster of dots that can be yellow or white in colour. Shapes are ranging from round to oval. This depends a little bit on the individual butterfly species.

Caterpillar in cannabis

Treatment and Prevention Methods: Biological Warfare

Especially when growing outdoors, growing organic can be good approach to produce high-quality cannabis without harming for the environment. Nature generously provides everything we live off: Clean air and water, food, textiles, and most importantly, beautiful cannabis blossoms. This is why it’s so important to preserve it for future generations of earth’s citizens and stoners. This article provides information about biological/organic methods to battle caterpillars.

Nature regulates itself and always tries to bring things in the right balance. This is crucial to understand when dealing with pests because we partly interfere with these regulating mechanisms. Oftentimes nature takes care of problems like this but large monocultures, used by commercial agriculture, are destroying biodiversity at a rapid pace. This actually hurts us, the eco-friendly cannabis grower.

Here are some things you can do without spraying chemical pesticides:

  1. Remove all the caterpillars you can find by hand. Either let them crawl in a garden of someone you don’t like, or kill them. It’s up to you. Just throwing them away is not sufficient because they will come back.
  2. Introduce parasitic wasps to your outdoor grow. There are web-shops in most countries that conveniently deliver beneficial insects to your home. These wasps lay their eggs on the larvae of the butterflies. Newborn wasps will feast of these organisms.
  3. Get your hands on some praying mantis. This is a good option if you live in warmer climates because they don’t do very well when temperatures are too cold. These elegant predators are not leaving the plant until every caterpillar is killed and eaten up.
  4. Spray your plants with neem oil. It won’t be very effective if you already have a large caterpillar population on your plants, but neem oil is always a good option to prevent pests from overpopulating your plants in the first place.
  5. Apply a biological product like Biothur (Trabe), Spruzit Concentrate (Neudorff), or Pireprot (Ecoprotec). These products are tailored to get rid of larvae plagues and are generally made from gram-positive bacillus that is found in natural soils.

Even if all of these products are biological, keep in mind that some people, including you, might smoke or digest the cannabis blossoms you grow. Don’t apply them during the last 14 days of flowering if you want to harvest a product that is free of any traces.

Caterpillar In A Cannabis Plant

Last words about pests and cannabis growing

Have a good time growing this magnificent plant and remember to be thoughtful about your decisions when dealing with pests of all kinds. It’s better to lose some parts of your harvest then to have a product that is highly contaminated with pesticides.

Most people prefer Cannabis because it’s a natural product, grown by Mother Earth. Respect nature and the organisms that live on this planet. You will be rewarded for this. It’s nothing but a matter of time. Grow healthy plants, big buds, and a superior quality product!


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