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One of the more frustrating problems when growing cannabis is pests invading your grow. Russet mites is one pest that growers pray they don’t encounter. A russet mite infestation can be pretty devastating for cannabis plants if not handled properly. This article will not only help you identify the signs of this stubborn infestation but will also equip you with all the information required to get rid of them.

What are Russet Mites?

Russet mites that go by the scientific name of Aculops cannibicola are tiny pests that are capable of destroying and killing cannabis plants. They are under 0.2mm in size and are usually pale, yellow, or tan in color. They are so small that growers do not notice the damage until the infestation becomes evident. Their growth is explosive in the conditions that are conducive to their propagation, for instance, in spring when the temperature is higher (around 70°F/21°C). Females can lay up to 50 eggs which take 30 days to grow into adults.

What makes these hemp russet mites so destructive is that they can spread quickly and infest numerous plants as their nymph can use air currents to go or float from one plant to another. Not only that, but they can also go from one plant to another through any kind of contact, for instance, clothing, plant matter, etc. They set abode on different plants and start destroying them going upwards from the bottom. A russet mite infestation is extremely bad for yield as they feed on the buds and flowers too. As a grower, you may not be able to put your finger on the problem in the early stages of infestation as you cannot see these four-legged mites with the naked eye but there are signs that you can use to make an accurate diagnosis.

Signs of a Russet Mite Infestation

Like numerous other pests, russet mites do not leave a bite mark signaling their presence. Hence, one way to detect the problem early is by monitoring the leaves at the bottom as these mites usually work their way upwards on cannabis plants. You will notice that leaves and stems appear dry and brittle. You will also see that leaves start curling upwards as they are deprived of their sap. In the case of a bad infestation, the top of the plant will start drooping. Necrotic spots or yellow spots resulting from leaf stress and a reduction in the size of the buds in the flowering stage are other tell-tale signs. Check for these signs if you have eliminated other causes like nutrient deficiency and are still speculating about the cause of over-all bad health of your cannabis plant.

Here is a list of signs that point towards russet mite infestation:

  • Leaf edges curling upwards
  • Bronzing or yellowing of leaves
  • Brittle and dry stems and leaves
  • Plant drooping
  • Necrotic or yellow spots
  • Stunted growth
  • Smaller buds

Since this pest is so small, you will need a microscope to see them. Therefore, a portable microscope will come in handy to finalize your diagnosis. In any case, there are ways to treat a plant that has a russet mite infestation.

Russet Mites Treatment

Russet mites are very difficult to get rid of as they lay their eggs inside the plant. But if you stay consistent and devise a strategy, you can save your cannabis plants from these pesky pests. It is recommended that you eliminate all of the heavily infested plants from your grow space as the nymphs can use horizontal air currents to travel from one plant to another. This will help you focus on the plants that can still be saved. If you have a bad infestation, you must consistently treat the plants numerous times. Also, it is advised to continue the treatment for a while even if you think that you have eradicated these pests – since they tend to come back very easily.

Here are a few treatments that can set your cannabis plants on the path to recovery:

  1. Neem Oil: Neem oil is a natural miticide and insecticide. Although, it is suggested to avoid using it during the flowering stage as it can leave a smell on the buds. Neem oil is undoubtedly an effective treatment against russet mites and many other pests. It is recommended that you dilute it with water and keep the usage low. Use a mister to spray it on the plants.
  2. Sulfur: Wettable sulfur is another cheap solution when it comes to eradicating russet mites. It must come in contact with the mites to kill them effectively. Mix 2 teaspoons of sulfur into a gallon of water and then spray it on the plants. Make sure you water your plants prior to treatment to mitigate any damage. Alternatively, you can opt for sulfur plant fungicide.
  3. Diatomaceous Earth: This fossil-based powder help kill these mites by simply dehydrating them on contact. This is more of a mitigator and less of a complete remedy. Add diatomaceous earth to your growing medium and use another treatment alongside for better results.
  4. Horticultural Oils (Essentria IC-3): Horticultural oils have proven to be effective against russet mites. Re-application is mandatory as this only stays effective for a few hours. Follow the instructions and use a sprayer to apply evenly on leaves.
  5. Insecticidal Soaps: On contact, these fatty acid salts can kill the help russet mites by weakening their exoskeletons and making their shells fragile. They are relatively safe and also require re-application.
  6. Natural Predators: Natural predators help prevent infestation and can also help with controlling it. These predators are available commercially. You can purchase Neoseiulus californicus, Galendromus occidentalis, and Amblyseius andersoni. They are not very effective because the conditions that are favorable to growing cannabis may not be so favorable for the survival of these predators.
  7. Heat: Some growers use heat to get rid of these mites. Overheating may slow down the growth of these mites, but it can also cause damage to the plant.
  8. Other Harsh Treatments: If nothing works and the infestation gets worse, you can rely on some harsher solutions like Forbid and Avid. There are a couple of these chemical-based products that are available in stores, for instance, Mighty Wash, Avid, Forbid, Azamax, Floramite. Etc. These are strong miticides and you must follow the instructions if you resort to using them. Russet mites can develop resistance or immunity against these chemicals, therefore, it is recommended to switch back and forth between different solutions.

How To Prevent Russet Mites

A russet mite infestation can result in growers having to kill off plants. Therefore, you must take a proactive approach and take measures to prevent these mites from getting to your precious cannabis plants in the first place. Do not bring in any new plants or even cuttings without quarantining them first for a few days. It is better to avoid walking directly into your grow room directly after you have been outside. If your plants are suffering from a russet mite infestation, do not give up; stay consistent in your fight to eradicate them. Your cannabis plants can recover and you can still get a great yield!