They can appear dark colored like the ones above, but also yellow, transparent or golden
They pierce cannabis leaves with their mouths and suck out all the good stuff, leaving shiny (sometimes people think it looks slimy), silver or bronze spots wherever the leaves were bitten. The spots are bigger and more irregularly shaped than the bites left from spider mites. If it goes on too long the affected leaves may start dying.
Pyrethrin products break down quickly, over the course of just a day or two. The major problem with them is they are very toxic to bees. Although cannabis plants generally don’t attract a lot of bees, please use this as a last resort, and also try to use it right after the sun goes down because bees sleep at night. This lets it start to break down before they wake up.
Proven Thrip Remedies
Spinosad products are organic and unlike many other thrip pesticides, completely harmless to pets, children, and plants. Unlike many insecticides, you can spray spinosad heavily on leaves and roots with basically no negative effects. Spinosad products can be used directly to kill thrips on contact, but can also be used when watering plants to systematically kill thrips via the roots. Spinosad is also effective at fighting caterpillers, spider mites, and many other marijuana pests.
2.) Neem Oil
Here’s a picture of an adult thrip on a finger for scale – they’re tiny!
3.) Spinosad Products
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.
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!
Finally, and as happens often with pests and diseases, some cannabis varieties are more resistant to thrips than others, so using the most resistant individuals will ensure healthy crops free from insects.
In severe cases, the leaves may also be deformed, suffering necrosis and dying in few days.
Thrip and marijuana
As we already mentioned, thrips are a group of small insects (1-2mm in length) formed by several species which attack a large number of plants and cultivars. They are actually the smallest flying insects found around the world. The most common species found on cannabis plants is Frankliniella Occidentalis, which can be found almost anywhere and is also primary vector of a large number of plant viruses. If environmental conditions are optimal, they can produce up to 11-12 generations per year..
Cannabis leaf with thrips
Thrips normally enjoy warm climates with constant temperatures (24-28ºC) and relatively low humidity levels. If these conditions are found – and there is not any prevention system – their presence will be obvious on the entire crop in a few time.
Using yellow sticky traps greatly helps to control the population of adults (and also to detect their presence), since they’ll stick to these traps letting us know they’re threatening our plants. Also, our grow room should be clean and free from insects and dead plant matter and we should disinfect all growing tools and equipment (scissors, pots, etc.) between harvest and sowing. Removing other plants and/or weeds (especially outdoors) is also useful, since they could be used by thrips to propagate and infect our plants later on.
In the event that – depite our prevention measures – we find thrips in our grow room we can use any organic insecticide (they work great gainst thrips) every 2-3 days and until we see no signs of activity on our plants. Potassium soap and pyrethrins (chrysantemum extract) are excellent options. They’re even more effective when used together. If these products are not enough, we can use chemical insecticides like Confidor (Bayer), although we’ll only use this type of products as a last resort due their impact on the environment (and the grower himself).
Yellow sticky traps work great to combat thrips
How to treat thrips on cannabis plants While thrips (insects of the Thysanoptera order) are not usually a serious thread for our crops, thay can be a pain in the neck if not identified and