by Nebula Haze
How to Get Rid of Mealybugs on Your Cannabis!
These white and hairy bugs enjoy warm temperatures and don’t tolerate the cold. They have even been known to grow and spread even on a drying plant after harvest, so watch out! They also leave patches of what appears to be white mold (sometimes confused with WPM), powder or webbing.
A white hairy mealybug crawling on a cannabis leaf
Mealybugs leave white patches almost like mold, powder, or webbing. Check out the video on Youtube to see what they look like when they’re moving.
Immature mealy bug
Mealybugs produce a sweet sap-like substance called honeydew
If you see bugs that looks similar except they’re dark and unmoving, you actually have scales (a related insect but it doesn’t crawl around like mealybugs do)
You may need to reapply soaps or oil if mealybugs come back. It may help to try more than one method, and if you see mealybugs again, definitely reapply immediately. Consistently treating your plants will get rid of them, even if it takes a few attemps (and a little patience).
Don’t spray with everything at the same time. Do them one at a time in succession. Do the insecticidal soap one day, then alcohol, then neem oil, all on differnt days. These treatments can be hard on your plant and a lot at once can be too much, so you don’t want to go overboard.
1.) Remove as many as you can with a water spray or otherwise manually remove them to get numbers down before you start with other methods
If you blast the plant with a strong stream of water outside, trying to blast off all the bugs, that can be a good way to get their numbers down dramatically before you start with one of the other treatments.
Doing this regularly can definitely help, but should be combined with at least one of the other methods to just make sure you’re getting all of them.
If possible, spray off as many bugs as you can. An adjustable mister like this one works great because it lets you adjust the power of the spray.
2.) Insecticidal soaps
Fatty acid salts or insecticidal soaps can be a good choice against mealybugs. They weaken the outer shell but are safe to use on your plants and they don’t leave much of a residue.
With soaps, coverage is very important as it does not stay on your plant for long, so follow-up applications may be necessary. Although this is considered safe, avoid getting any on your buds!
Natria is a good example of an insecticidal soap
3.) Neem Oil
Neem Oil will leave an unpleasant taste/smell on buds when used to treat flowering plants, so again, don’t let this stuff get near your buds! There’s also some evidence Neem oil may be harmful to humans so use with care! That being said, Neem oil is an all-natural remedy that is very effective against many different types of bugs and mold including mealybugs. You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly, since neem oil and water can separate easily.
Alcohol tried out the waxy outer coating that protects mealybugs, so there’s a few differenct ways to use alcohol to kill them.
If it’s a small plant, you might be able to put rubbing alcohol on a cotten swab and use it to kill each bug one at a time, to immediately get rid of most of the adults. This might be an option if you’ve only got a few, or in addition to another method.
You can also make an alcohol-water spray, and use a mister (also called a “One-Hand Pressure Sprayer”) to spray all the bugs on the plant.
Make a solution of 9 parts water to 1 part rubbing alcohol and spray plant once a week until mealybugs are gone. With an alcohol-water mixture, the goal is to spray the mealybugs directly to kill them. Since all the alcohol will evaporate into the air within minutes, it won’t give your plant a protective “coating” like soaps or oils.
5.) Beneficial Insects
Beneficial insects, such as lady beetles, lady bugs, and lacewings may eat large numbers of mealybugs and are welcome guests in the garden. Although you can order ladybugs to release around your plants, they tend to fly away in just a day or two. Additionally, the reproductive capability of mealybugs is so great that the impact of the natural enemies may not be enough keep mealybugs at or below acceptable levels after an infestation has already gotten started. But they definitely don’t hurt!
Release natural predators like ladybugs in the grow space to help eat some mealybugs
6.) Diatomaceous Earth
Sprinkle food-grade diatomaceous earth over exposed parts of soil. This will help kill the mealybugs and will also help prevent infestations in the future. While not completely necessary, adding diatomaceous earth is a great step to take to help get rid of the mealybugs and their young as fast as possible
Diatomaceous earth is an organic insect killer made of fossilized shells. It is sharp on the microscopic level and works by puncturing the exoskeleton of insects (draining them of their body fluids), but poses no harm to humans or pets and can even be eaten.