I was recently asked for tips of the trade concerning russet mites. Russet mites stunt the plant, the leaves become brownish yellow and droop while the mites suck the resin out of the maturing flowers. Apparently we're not the only ones that enjoy a good bud. Before I posted my own personal opinion I wanted to do some research. Eating dinner and scouting the web for info, I nearly lost my appetite seeing close-up photos of these buggers. They're white, tiny, squirmy, maggoty-looking, and nauseating. You don't want them scouring your plants; they are voracious and nasty. Not to mention that you might have to kiss your crop goodbye if they infest it. They're often misdiagnosed for rust or nutrient deficiency because of their microscopic size.
Because they are so infectious, if your neighbor has it, most likely you will also. They can travel by wind,on seeds, dried bud, clothes, nearly anything. They eat new growth and trichomes (nerd for the resin glands), so it's one of the worst pest a grower can come across. Because they are so small, you might see damage already done before seeing them. If you notice leaf edges curling up and a light yellowish powder on the infected parts, then you may have reason to worry.
Like with anything terrible you want to avoid: prevention is key. Inspect your plants frequently; and if you bring in new plants, quarantine them first to prevent any spreading. Contaminated potting soil that carry female mites or eggs can as well cause an outbreak. Also, consider using a preventative foliar spray regularly. Some of the safeguards and treatments used on spider mites can apply to russet mites. When treating your plants look to see if damage has stopped. Remove all the damaged stems, leaves, or even the entire plant. Discard them in such a way that will not cause spreading of the mites or eggs like in a sealed garbage bag.
Let's first look at prevention in an indoor garden. First thing to do if you've been infested is lower the temperature and humidity of your garden to slow reproduction rate; females can lay up to 50 eggs a day- giving rabbits a run for their money. Keep an ultra clean grow space. Don’t bring in unnecessary tools that's been used outside; they are a hitch-hiking plague. Intermittent releases of spider mite predators in an indoor grow space can help keep pests at bay. Some of the following products have been used with some success: canola oil sprays, sprays containing sulfur, pyrethrins or neem oil. If you don't have success with this then I painfully suggest you swallow your tears and... torch your garden and start fresh! Bleach your workspace from top to bottom including benches, equipment, and literally everything else. Throw away soil, everything new.
Now let's focus on mite problems in an outdoor garden-where they are usually found. Don't over-fertilize you plants. This vermin is attracted to robust green growth that comes of excess nitrogen. Like in indoor gardens, release of predatory mites can slow down infestations, giving you time to deal with them. Although, if you use certain sprays, they also kill the helpful mites. The same sprays mentioned above for the indoor garden can be used for your outdoor garden as well. Don’t wait to see how effective one treatment is before continuing or using another. Once infestations spread up plants, it’s practically hopeless to save the plant. Don’t think twice before throwing away entire plants, even if they’re not entirely affected. While you’re treating infected plants, the mites are hastily dispersing to others.
Stunted and deformed
These pests have a 30 day light cycle meaning that it's likely you won't detect something wrong till 2 cycles have passed due to the fact that they do little damage in the first cycle. Based upon their population, their infestation can be categorized in 3 stages. The first stage is is when the eggs are laid, usually on the bottom of the leaves. The hatched larva will eat a ring around the egg. Look for a very small brown ring to give you indication of their presence. If you were a good person in your past life and the gods were smiling upon you then you'd find these nearly invisible pests in their first stage.
In the 2nd stage you will see more brown spots appearing. If you had cropped and pruned your plants their might be an orange discoloration around exposed sap where they have come in for easy feeding. By now there has most likely been 2 thirty-day cycles and you will see under a microscope eggs, larvae, and adults.
By the 3rd stage you will see a lot more damage, especially to the lower bottom of the plant. New growth will be stunted and deformed, and buds attacked will appear withered. Increasing in numbers, the pests will spread to all parts of the plant, and will eventually sap the entire plant. Anyone scared yet? You should be.
Like many of you out there battling the evil forces of russet mites, I too, would give up my right arm (hmmm wait, maybe a pinky finger) if it meant that every single russet mite on this earth would self combust. Until that is a possibility I urge you to stay in stealth mode and conquer their infestation. Like my mother always said, “cleanliness is next to godliness,” and although she most certainly didn't mean it in this regard... she was spot on when it comes to russet mites.