Two-Spotted Spider Mites and how to control them!
What are Spidermites?
Two spotted Spidermites are a small, pinhead sized mite that lives on the underside of your plant foliage. They are very small, and when against the green foliage, can be quite hard to see with the naked eye. Spidermites puncture the external protective tissue of your foliage to extract the moisture from inside the leafy tissue.
Where do Spidermites live on my plants?
Spidermites live on the underside of your foliage, and are rarely found in soil, on the pot or crawling on the top of leafs. Quite often if you find spidermites crawling on the top of your foliage, it is much too late, and you will already have a severe infestation.
Large Spidermite Colony
Magnification video shot using a 60x Cell phone magnifyer
You can find Spidermites in small colonies hiding under the protection of the hills and valley created by the veins on a leaf. Spidermites will cast a nearly invisible web from vein to vein, creating a little protected cavity where they can lay eggs, to be protected from wind, rain and predator insects.
Two spotted spidermite egg
The valley between to veins where mites like to colonize
How will I know if my plants have Spidermites?
1. Leaf Spotting
You'll find discolored spotting on the top of the leaf, which is signs of the damage the spidermite is causing on the underside of the leaf. Try holding a flashlight on the underside of the leaf, pointing through the leaf, and view from above to see the spotting easier.
Spidermite spotting on an Alocasia Leaf
Spidermites are known for leaving a trail of dead mites and exoskeletons in their wake. You can expect to see debris and dirt stuck to the nearly invisible spidermite webs. So expect to see lots of debris on the underside of a mature infestation. Typically you can expect to see exoskeleton accumulation as the Spidermites grow. Very similar to Aphid exoskeletons, you will notice crispy white shed on the underside of the leaf.
Spidermite Exoskeleton Debris
3. Stunted Growth
A serious enough infestation of spidermites can cause serious stunting of new growth. If your plant isn't growing like you expect it to, if new foliage is coming out slower than normal, you may want to have a close look at the underside of your leaves.
How long do I need to treat my plant?
It's important to first understand why we need to treat for such a long time.
Two-spotted Spidermites can mature from Egg - Adult in as quick as 5 DAYS! Which means if you are treating your plant and wait 5 days between treatments, you can already have eggs hatch and have that same mite lay more eggs on your plant in that time. And the unfortunate part about that is, nothing kills Spidermite eggs! So it super important to be diligent and treat every 3rd day for at least two weeks.
Enough! How do I treat them?
1. Physically remove the Mites from your foliage
When you have a mosquito on your arm, whats the best way to remove it? Spray it with repellant? Whats the best way to remove a grasshopper that jumped onto your pants? Spray it with a pesticide? No! Just wipe them off! With that same logic, we recommend doing the same to your houseplants or cannabis. We recommend taking some fresh paper towel, damping it with warm water, and physically wiping the spidermites, debris and invisible webbing from the foliage. Get a new scrap of papertowel, and repeat the process until you have cleaned a majority of the plant. This gives you a great headstart to being bug free and should immediately remove a large majority of the mites from your plant.
Shawn wiping the underside of an Alocasia
2.1 KOC Pesticides (Kill on contact)
Few things are more effective than just nuking them with a KOC (Kill on contact). Doktor Doom House & Garden, Doktor Doom Spidermite knockout, House and garden Raid. These are all KOC's. Once that pesticide touches the bug, the bug dies. These will be slightly tough on your plants (even though it is designed to be sprayed on plants with bugs) so we recommend spraying your plant with water a couple minutes after your treatment to clean the pesticide residue off your plant.
2.2 Soap residual Pesticides
Soapy pesticides like safer's work in three different ways. Potassium salts will soften the outer body of the spidermite, Pyrethrins attack the nervous system of the mite causing the feeding to stop immediately, and the neem oil suffocates the mite in a soapy neem layer.
Bottled Persimilis Mites
Persimilis Mites & Fallacis Mites are both a beneficial predator to the two-spotted spidermite. Persimilis Mites more for current infestations of the two-spotted mite. Fallacis more appropriate for Preventative applications.
Even with Beneficials, multiple treatments are necessary. Both mites prefer an easy meal, which means they would much rather find eggs and freshly hatched Mites to eat. After they have exhausted the easier food supply, they will move to the more agressive mature two spotted spidermites. This is when it is a great opportunity to release a second wave of Beneficials onto your plants. This is also a good time to treat with a pesticide, as the Persimilis mites have had a go at the spidermite population eggs and young for a few days, and your pesticide can clean up the mature mites.
Beneficial Persimilis Mites on papertowel
What are the steps to start the Spidermite battle?
1. Quarantine your plant away from the rest of your houseplants.
2. Take warm water and paper towel and physically wipe the foliage that you can. If you have a sever infestation, it might be worth it to prune much of the infected plant and wipe the remaining.
3. Spray your plant with your desired pesticide. We recommend our Dr Doom Spidermite Knockout found HERE
4. Retreat your plant every 3rd day for 14 days
5. Keep your plant quarantined for a full month after you have finished treatment
Read about Mealybug Here: