How to Remove Red Spider Mites from Marijuana Plants

A bane of marijuana growers, red spider mites pose a significant threat to the health and yield of a marijuana crop.

This article provides a comprehensive guide on how to identify, prevent, and remove red spider mites from your grow site.

What Are Red Spider Mites?

Red spider mites are a common pest that feeds on marijuana plants. They are arachnids belonging to the Tetraanychidae family, which is part of the broader Arachnida class of the phylum Arthropoda.

Red spider mites are known for reproducing rapidly and inflicting widespread damage by sucking the sap from the plant’s leaves. This can lead to discoloration, decreased photosynthesis, and, in severe cases, the death of the plant.

How to Identify Red Spider Mites

Knowing how to identify a red spider mite is essential for a marijuana grower. As the name suggests, they are red in color and resemble tiny little spiders. These little pests are minuscule and typically around 0.4 mm in size.

Red spider mites can be difficult to spot as they hide under the plant’s leaves. While out of sight, they spin delicate webs as a protective measure and to colonize new areas.

Signs of a Red Spider Mite Infestation

There are some telltale signs that you have a red spider mite problem. Some common indicators include:

Leaf Stippling

Leaf stippling is a common symptom of a red spider mite infestation. Look for pale or yellow spotting on the leaves, which occurs after the red spider mites have fed on the plant sap.

Webbing

Red spider mites spin webs on plants that serve as habitats and protect them from predators. They reproduce rapidly within these webs, laying eggs and creating dense colonies that can cause widespread damage to a grow site.

Leaf Wilting

Extensive feeding by red spider mites impacts the plant’s ability to retain moisture, leading to plant stress and leaf wilting.

Plant Death

A severe red spider mite infestation can ruin and kill your crop. Widespread feeding can impact photosynthesis, cause significant plant stress, and deprive the plants of moisture and vital nutrients, leading to death.

How to Prevent Your Crop from Being Infested by Red Spider Mites

When it comes to red spider mites and marijuana plants, prevention is definitely better than cure. Here are some proven methods to prevent a red spider mite infestation:

Keep your Grow Site Clean

A good way to prevent red spider mites from attacking your marijuana plants is to maintain a clean and controlled growing environment. Keep the grow site free of debris and regularly disinfect tools and equipment to prevent the spread of mites.

Temporarily Quarantine New Marijuana Plants

It is a good idea to isolate any new marijuana plants for at least two weeks before introducing them to the grow site to ensure they are free of red spider mites (or any other pest, for that matter).

Manipulate the Environmental Conditions to Deter Red Spider Mites

As red spider mites thrive in hot, dry conditions, you can deter their proliferation by maintaining a cooler, more humid environment. Experienced marijuana cultivators say that maintaining temperatures below 68°F (20°C) and humidity levels above 60% are effective at preventing the proliferation of red spider mites.

How To Remove Red Spider Mites

If red spider mites manage to breach your defenses and infest your plants, you can eliminate them by employing some of the following proven methods:

Introduce Red Spider Mite Predators

You can manage red spider mites by introducing some of their natural predators into your grow site. Red spider mite predators include the predatory mite Phytoseiulus persimilis, ladybugs, and lacewings.

Remove Red Spider Mites Manually

If you are lucky and spot a red spider mite problem early enough, you may be able to remove them manually. You can do this by wiping down the leaves of your marijuana plants with a damp cloth. Alternatively, you can use a powerful water jet to wash away the red spider mites and their eggs. However, please note that this method is generally only effective when infestation levels are very low.

Neem Oil

Neem oil is a commonly used natural pesticide that effectively disrupts the life cycle of red spider mites without harming other beneficial insects. Neem oil works best when applied as a foliar spray. For correct application, follow the instructions as described on the product label.

Insecticidal Soaps

Insecticidal soaps are another proven way to deal with red spider mites. They kill mites on contact and do not leave harmful residues on the leaves. Insecticidal soaps break down the red spider mites’ outer layers, causing them to become dehydrated and die.

Essential Oils

If you want an all-natural solution to your red spider mite problem, consider using essential oils such as rosemary, peppermint, and clove to deter spider mites. Add the essential oils to water and spray directly onto the affected areas of the plant to create a foliar spray.

Use Chemical Pesticides as a Last Resort

Some cultivators resort to chemical pesticides in cases of severe infestation by red spider mites. However, you should use these products cautiously, as they can be harmful to the environment, beneficial insects, your beloved marijuana plants, and your own health.

Acaricides and systemic pesticides are commonly used pesticides. If you are going to use an acaricide, avoid using the same one over and over, as red spider mites can build up resistance over time.

Marijuana plants absorb systemic pesticides through their roots, which circulate throughout the entire plant. When the red spider mite feeds on the plant, it ingests the pesticide and dies.

While systemic pesticides are effective, it is important to be aware that harmful residues can remain in marijuana plants. Therefore, consuming marijuana buds recently treated with chemical pesticides poses a health risk. The level of risk depends on a number of factors, including the toxicity of the chemicals used and how recently the pesticide was applied.

In marijuana cultivation, the pre-harvest interval (PHI) is key. The PHI refers to the time of the last pesticide application before harvesting. It is essential to allow enough time to elapse so that the pesticide residues have degraded to a level considered safe by regulatory standards.

Final Thoughts on How to Remove Red Spider Mites from Marijuana Plants

It is essential to be vigilant and to continuously inspect your grow site for spider mites and other common pests. Focus on the undersides of the plant’s leaves and act fast if you discover them on your crop.

Prevention is definitely better than cure, but if you can detect red spider mites early, they are much easier to manage. Natural methods such as introducing red spider mite predators or using neem oil or essential oils are much better and safer than chemical pesticides that can leave harmful toxic residues in the plants.