Worse? While not a significant threat to outdoor growers, they thrive inside. Indoor grows and greenhouses are their favourite environments. They love high temperatures. Thrips can also be persistent if not treated properly. And if not eliminated early, they can significantly reduce yields.
Introducing natural predators like Orius laevigatus (the common bed bug) is another way to keep your harvest thrip-free.
If you want to use chemicals to clean your space and crop, try to use the least toxic substances available. Remember to use both masks and gloves when handling all toxic chemicals.
Eradicating thrips once they have established a presence is the only way to save your crops and prevent a new infestation. The best method (without using harsh chemicals) is to use potassium soap or neem oil. Pyrethrins and rotenone are also good options, although use sparingly as pyrethrins are also highly toxic to bees.
Regardless of their species, thrips are the bane of farmers everywhere. They can reproduce up to 12 times per year. When mature, they can survive just by flying from one plant to another. Outside of cannabis, thrips’ favourite crop seems to be cotton, although they can damage many kinds of crops. But they really seem to love cannabis! Unfortunately, they are particularly damaging when they appear early on in the grow process.
The most damaging thrip threat to cannabis comes from a species called Frankliniella occidentalis. These thrips are yellowish-white flying bugs. They lay their eggs on the plant itself. The first signs of their presence are small, silver stains or dots on the underside of leaves. This is how thrips lay their eggs. They are also easy to miss.
Growing cannabis can be an exciting and rewarding hobbie. But what happens if others decide to enjoy your cherished crop before you do?
Spinosad products are also organic and harmless to pets, children, and plants. Spinosad is an organic pesticide made from the fermentation of certain kinds of soil bacteria. This form of insecticide can be used both as a topical spray and at the roots. When added to water, these products are only good for about 24 hours, so only mix what you need at any given time.
The best way to rid yourself of thrips is to never have an infestation in the first place. Make sure that you thoroughly sanitise your growing space before you begin. This means not only keeping the place spotless, but removing all dead plant matter.
Thrips are a common pest facing indoor cannabis cultivators. They can seriously damage the plant and lower yields. Here is a guide on how to get rid of them.
Although it doesn’t really look like it in pictures, in real life thrip damage has been described as looking like “dried spit” or tiny snail trails.
Note: Most spinosad products are effective for only about 24 hours after being mixed with water, so only mix as much as you will need per application. Anything left over will be waste.
A Thrip nymph on a cannabis leaf – I hope this helps show you how tiny they are.
A closeup of another baby thrip in “nymph” form
Neem Oil will leave an unpleasant taste/smell on buds when used to treat flowering plants, so 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. 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.
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!
Here’s a picture of an adult thrip on a finger for scale – they’re tiny!
Examples of thrips damage on marijuana leaves (irregular silver or bronze spots)
If you see tiny, wormy little bugs, dark winged insects or bronzed discoloration on the leaves, you may have thrips. Learn how to get rid of them!