Picture of spider mites on a cannabis leaf – they’re tiny and often found under the leaves. Learn how to get rid of spider mites for good – this pest can be a marijuana grower’s worst nightmare! Spider mites have tiny sharp mouths that pierce individual plant cells and suck out the contents. This is what results in the tiny yellow, orange or white speckles you see on your plant leaves. Spider mites are common cannabis pests, especially when growing in soil.
Although less common in hydroponics, spider mites can show up in any setup where cannabis is being cultivated! Extreme Close-Up of Two-Spotted Spider Mites with Egg. Spider mites can be an especially tricky pest in the grow room. Since they are so small they can build up a big infestation before a grower even notices a single mite. Many growers see the distinctive tiny spots of a spider mite infestation and think it’s some sort of nutrient deficiency, not realizing it’s actually something far more sinister. An infestation often causes leaves with tons of spots/bites to turn yellow. Spider mites and their eggs, found on the back of cannabis leaves. If the infestation goes on too long, you’ll start to see webbing on your plants and buds. Here’s why… Rapid reproduction – a single mature female spider mite can produce a million mites in less than a month Disappearing act – spider mites often appear to be gone/killed, then they come back with a vengeance days or weeks later, right when you thought you’d gotten rid of them for good. Big appetites – spider mites can eat up your tender plants in an amazingly short amount of time; a bad infestation has been known to kill plants overnight Webbing – spider mites cover leaves and buds with a fine mesh of silk webbing, ruining whole crops even after you get rid of the spider mites Zombie-like resistance – spider mites quickly become immune to whatever you do to try to kill them; if you don’t take care of your spider mite problem by eradicating them completely from your grow room, you may soon find you have a population of ‘Super-mites’.
The two-spotted spider mite which specializes in cannabis seems to be particularly resistant to insecticides and is sometimes referred to as “the borg” in the cannabis growing community. These ‘borg’ spider mites with two spots on their back can be almost impossible to get rid of! Read one grower’s journey to get rid of the “borg” spider mites in his grow room. Spider mites often go unnoticed at first because they are so tiny that they look like spots to the naked eye. Male spider mites are about 1/50th of an inch long (.5mm) while females are slightly smaller at about 1/64″ (.4mm). It’s hard to imagine something that tiny, but the picture below might help give you an idea of how small they are: Under a microscope you can see they have four pairs of legs, no antennae and a body shaped like an oval. When spider mites attack a particular spot and you see lots of speckles near each other, the leaves may start looking yellow or bronze. Although it starts with speckles, this pest has certainly earned the “spider” part of its name from the distinctive silk webbing they spin on vegetation, leaves, and flowers once an infestation really sets in. Web-producing spider mites may completely coat the foliage and flowers with the fine silk, which collects dust and looks dirty. With flowering plants, you may even see entire buds get covered in fine webbing from a bad spider mite infestation. Spider mites have a life cycle that helps them re-populate quickly and effectively after much of their population has been destroyed. Adult females begin the cycle by laying eggs, often on their host plants. In days or weeks, an egg will hatch and become a larva, which is the first stage of life. Larvae are round-bodied and have only three pairs of legs. The larvae feed for a few days, seek a sheltered spot to rest and then molt into the first nymphal stage. The first nymphs feed a few days, rest and molt into the second nymph. The second nymphs feed, rest and molt into the adult stage. Overall, it can take days or weeks for spider mites to go through their whole life cycle. Here are adult spider mites with eggs Image courtesy of Natalie Hummel, Louisiana State University AgCenter, Bugwood.org. Because of this variable growth process, it’s common to think that you’ve eradicated the spider mites in your grow room while they’re secretly building up numbers in one of their immature stages. This is why it’s so important to keep treating your grow room after a spider mite infestation even if it appears that all the spider mites are gone. Just pretend they’re hiding and doing pushups, just building up their numbers for a second infestation. Treat your grow room like a war zone, and don’t allow the spider mites to build up any numbers and attack again! Growers Need to Take Spider Mites Seriously… Or This Can Happen!
Spider mites are tiny and can be detected only by a full and thorough leaf inspection (on both sides of the leaf). If you find Spider Mites or eggs you must act fast and hit them hard. Spider mites can be very quick to take over your plant, and even quicker to develop a resistance to almost any method you use to get rid of them, which is why it’s generally recommended to use multiple methods of offense against a spider mite infestation. If you have problems with spider mites, keep a constant and varied offense for the best chance at success. It can help to identify how/where you got spider mites. If you already have an infestation, you will immediately want to start hitting them hard with something that will kill them on contact (several options are listed below). Tracked in from outside Vegetable garden Animals/pets From a plant other than marijuana. If you have some spider mites which got tracked in randomly from outside, it’s likely you’ve got a run-of-the-mill spider mite that should be easy to get rid of. Although these guys are annoying as well, they almost seem nice compared to their cannabis-specialized counterparts. Chances are you’ll be able to successfully use one of the less harsh home remedies to stop your infestation.
From another marijuana garden Clones were infested with spider mites Tracked spider mites in from another marijuana garden Any time the spider mites were living on another marijuana plant before they got to your plants. If you got your spider mites from a cannabis clone or plant from another cannabis grower, chances are you’ve got the type of spider mite that is an expert at infesting cannabis plants .