Tips on How to Get Rid of Caterpillars

how to get rid of caterpillars

Planting, cultivating, and waiting for your marijuana garden to grow takes a lot of effort and patience. And when you are waiting to see all your hard work come to play, it is very important to know how to get rid of caterpillars from your garden. While most people think that these little creatures cannot cause too much damage, these cute and fuzzy insects can cause quick damage and destruction on your prized possessions. All it takes is about five caterpillars to completely demolish a healthy and mature plant making them one of the most feared pests by cannabis growers.

Signs of Caterpillars on Your Cannabis Plants

Growing cannabis plants outdoors come with several benefits, including natural light, more space, and bigger yields. Unfortunately, this also comes with the risk of having local wildlife and insects feasting on the crops. This, of course, includes the soft-bodied caterpillars. While there are over thousands of caterpillar species known today, a select few are the most problematic to cannabis growers. One of these is the Cabbage Looper, which loves marijuana plants and especially their large, fan leaves. The Hemp Borers, on the other hand, love the buds.

A caterpillar infestation can range from mild to total devastation of your entire crop. Regardless of the severity, here are some symptoms that will help you identify if you have a caterpillar problem at hand.

  • Irregular holes on the leaves. Leaves are the first vital substances for newly born caterpillars. They will chomp on the leaves and leave oddly shaped holes on the leaves. Different species of caterpillars prefer different types of leaves.
  • Caterpillar droppings on the leaves. Caterpillars leave behind a lot of poop, which are technically known as “frass.” If you look on the underside of the leaves, caterpillar droppings may be in clusters or may be laid singly. Their colors range from white to green to brown to black. These droppings can also encourage the growth of fungus, usually botrytis.
  • Wilting flowers, yellowing leaves, and damage to the stems. As mentioned above, different species of caterpillars prefer to chew on different parts of the plant’s anatomy. The Hemp Borers, for instance, is one of the most concerning pests for flower buds growers. These caterpillar species tunnels through the stems of the plant where they hide, feeding on the marrow in the stalk, and creating damage and destruction especially in flowering tops. As few as ten larvae per plant can effectively cripple seed production and plant growth as each larva can consume an average of 16 cannabis seeds. Leaf yellowing, especially on the top leaves, is the result of the damage to the stems, which can affect nutrient and water transportation.
  • Slime trails. Some caterpillar species leave behind a slime trail when they crawl across the surface of the leaves. Holes in the stalks and branches with brown trails around them should also alert you of caterpillar activity in your cannabis crops.

How to Get Rid of Caterpillars on Your Cannabis Plants

Once you’ve identified caterpillar activity on your marijuana crop, you must act quickly as possible to avoid looking at all your months’ worth of efforts go down the drain. Here are some biological and organic remedies you can use to get rid of caterpillars quickly and effectively:

  • Manual removal. A simple and pretty straightforward way to remove caterpillars is to remove them all by hand and relocate them far enough from your cannabis plants. While this method may seem unpleasant to many people, it is an effective way of eradicating infestations quickly. Just make sure to arm yourself with plastic gloves (to prevent stings and rashes) and a whole lot of patience. While caterpillars are easy to spot using the naked eye, most species are exclusively nocturnal so prepare yourself for some night time caterpillar hunting. Start at the topmost part of your plants and work your way down. 
  • Introduction of natural predators. Natural predators of these caterpillars, like the parasitic wasps, will most likely come all on their own as soon as they sense caterpillars nearby. These wasps usually lay their eggs inside the caterpillars and when they hatch, they end up as predators, eating their hosts entirely from inside out. While this natural way of controlling caterpillar populations is nothing short of horrific and sinister, it removes the need to use any chemical sprays or solutions on your plants. Aside from these parasitic wasps, praying mantises are also nature’s way of managing and eradicating most pest problems. These finger-sized insects are one of the few active hunters that will stay until all caterpillars in the garden are fully devoured. If you have a history of caterpillars in your cannabis garden, it is best to introduce these species to your crops.
  • Bacterial sprays. Bacillus thuringiensis is a species of bacteria that can be used as an insecticide spray. This bacterial spray has been used since the 1920s and is one of the most commonly used sprays in organic farming. The bacteria are known to kill the larvae of many species of butterflies and moths, making it one of the most effective ways to control caterpillar infestations. Simply spray your plants with Bacillus thuringiensis and upon digestion of the plant tissue, the caterpillar falls ill from irreversible damage to its digestive system and dies. It is important to remember, however, that while this is an organic and biological product, this spray should not be used on the last 15 days of the growth cycle of your cannabis crops. In this way, you can avoid affecting the taste of your final products. 
  • Homemade insecticides. There are several homemade insecticide remedies that you can apply to your plants. Combined with manual removal, these insecticides will work very well against any caterpillar plague. 
    • Pepper and garlic spray. A potent mixture of pepper and garlic is one such remedy. Simply combine one whole minced garlic and one tablespoon of dried red pepper flakes with a gallon of water and puree the mixture together in a blender. Pour it into a glass jar with an airtight lid and set it under direct sunlight for 24 to 48 hours. Strain the solution through a filter and transfer the clean solution into a spray bottle. Spray wherever needed to keep the hungry caterpillars at bay.
    • Neem oil spray. Another easy remedy to a caterpillar problem is a little neem oil (about 2 ounces or less) and water (one gallon) mixture. This spray is very effective for caterpillar control and should be applied to affected plants only in the evening as the sun will render the solution useless. This mixture will lose its potency after four to eight hours so only concoct enough solution for the day. Make sure not to overdo it as the spray can also harm beneficial predators.
    • Pyrethrin spray. This spray is from chrysanthemums and is also an effective natural insecticide against caterpillars. Just like the neem oil spray, however, it is important to spray with a light hand as the spray can harm beneficial predators and in high levels, it can cause asthmatic breathing, headache, and nausea in humans. To create the spray, mix1 tablespoon of chrysanthemums flower heads with 1-liter hot water and allow the water to stand for at least one hour. Strain off the flower heads and then add a pinch of soap powder, mix, and transfer into a spray bottle. 

There are several benefits associated with growing cannabis outdoors. Unfortunately, this also means higher exposure to possible infestation against unwanted pests, including some hungry marijuana-loving caterpillars. Aside from identification, knowing how to get rid of caterpillars is vital to every plant and cannabis grower. While moths and butterflies may be pretty to look at, they can bring death and destruction to your prized cannabis crops.

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