Thrips

Wondering how to deal with thrips? Keep reading, I've got great solutions for ya!

I recently had a bad thrip infestation that devastated my plants and left them dead and sad within days.

They especially enjoyed wrecking my millet cover crop, and I was completely surprised to see so much damage as I didn't catch them early enough.

Here we'll delve into what thrips are, what they do, and most importantly - some ways you can actually deal with them.

What Are Thrips?

Thrips are sap-suckers. They latch onte plant tissue, especiall leaves, and suck plants of their nutrients and moisture.

If allwed to grow in size, a thrip outbreak can be devastating to plants which might not be capable of growing faster than the thrips can multiply.

They are especially a problem in greenhouses and indoors, where natural thrip predators aren't present.

How to Deal With Thrips

Insecticidal Soap

Grab yourself a bottle of castille soap like Bronner's, put a few squirts in a spray bottle and fill it up the rest of the way with water.

Give it a shake, and then spray your afflicted plant leaves and stems every day or two. Soap is pretty effective at drying out and killing most things with exoskeletons, and thrips are no exception.

DIY Raised Bed Plans

Build Yours Today!

Note that the soap will leave a white residue of saponins on your leaves, which you'll want to wash off before consuming.

Most plants tolerate these castille soap foliar sprays quite well, with a few exceptions. If your plant looks worse after soaping it up a few times, discontinue use and consult your plant doctor immediately.

In a lot of cases if your thrips are really sucking the life from a plant, a few targeted applications of soap and a few days to recover will often see plants perk back up and look healthier than they have in a while.

One note here - if you're growing cannabis and it's already in the flowering stage, do not apply soap. It will seep deep into the flower buds and be very difficult to wash away. Not to mention that flower buds are best kept as dry as possible to prevent mold. This may apply to other flowering species as well if you plan to consume the flowers.

Blast 'Em!

Thrips are not that great at holding onto leaves and stems in the face of high-pressure water sprays.

Grab yourself a pump sprayer, pump it up real good, and blast the thrips off your plants. It may take a little while to target them all, but this can effectively knock a majority of the thrips off your leaves and stems immediately - allowing plants to recover before pest populations bounce back.

This works really well for flowering cannabis, where don't want soap in your buds. Just be sure that your lights and fans will be on after, or that you've got some sunny warm days ahead for the buds to dry out. The last thing you want is to trade thrips for mold.

Given the time to dry after some high-pressure water blastin', your plants should be able to bounce back very quickly. This also helps get rid of thrip poop which nobody wants on their plants.

Pair a water blasting with the castille soap application mentioned above, as a way to clean off your leaves a day or two after you soap 'em.

Beneficial Insects for Thrips

If you're a systems thinker into holistic approaches and ecosystem balance, you're likely asking yourself "what eats thrips?"

We always advocate for balanced systemic approaches here, rather than reactionary chemical use, or futile manual bug-squishing/vacuuming which solve nothing long-term.

Great news! There are MANY creatures which eat thrips and will target them better than you or chemicals ever could.

Let's talk about some of the most common ones that will help balance your ecosystem and keep thrip breakouts under control naturally.

Do Ladybugs Eat Thrips?

Ladybugs or Lady Beetles are a generalist species which will absolutely eat thrips, plus a whole bunch of other pests including but not limited to:

• Thrips
• Aphids
• Mealybugs
• Leafhoppers
• Alfalfa Weevils
• Chinch Bugs
• Grape Root Worm
• Certain Mites

Amblyseius Cucumeris Controls Thrips

I like using predatory mites like this for indoor applications, as they will stay in isolated areas better than ladybugs will.

Always check if predatory species are invasive in your area before releasing beneficials outside!

Amblyseius Cucumeris is a great preventative mite because it feeds on immature stages of thrips (larvae) and other obnoxious mites. These include but are not limited to:

• Broad Mites
• Spider Mites
• Russet Mites
• Cyclamen Mites

When there aren't adequate pests populations available for your Amblyseius Cucumeris friends, they'll happily switch to pollen as a main food source just like ladybugs.

Be sure to provide numerous choices of flowering plants for your predators to utilize as their backup food source when pest populations dip.

Minute Pirate Bugs

Orius insidiosis, known as the Minute Pirate Bug, is a voracious eater with an appetite for many common garden pests, thrips included.

Dig Cool Merch?

Grow Plants Sequester Carbon
~ T-shirt ~ Shop Now

Cobbed Too Far
~ Sticker ~ Shop Now

Brocc-Head
~ T-shirt ~ Shop Now

Also on the menu for pirate bugs are aphids, spider mites, and moth eggs, among others.

Estimates for how many thrips they'll eat range from 10-30 per day, however they kill far more than they eat, sometimes up to 100 thrips per day.

These critters are incredibly effective at thrip control, and I especially love using them in greenhouses, indoor grow tents, and grow rooms where they can be contained so they stick around longer.

Providing supplemental food is a good idea for most predatory insects, so they remain around after most pests are eliminated. This is because pests will inevitably never be fully eliminated and their populations will always bounce back. If you can supplement their diet when pests dwindle, pirate bugs will still be around as thrips bounce back.

Many beneficial insect businesses offer supplemental food options to keep predators well-fed when there aren't enough pests to chow down on.

I also always suggest having flowering plants around for predators to feed on when prey populations drop. Orius species will consume pollen and nectar from flowers when food is scarce.

It's worth mentioning here that Pirate Bugs can and do bite humans and pets, and their bites are reported to not be much fun.

That said, this is likely not much concern outdoors, or in contained greenhouses, grow tents, and grow rooms. It might be a concern if you release them in an open area in your house such as a windowsill herb garden, where they can't be easily contained. Remember, they would still much rather bite thrips than bite you, and I've never had an issue with them before.

Nematodes That Target Thrips

Trips spend their prepupal and a pupal stages in the soil, and the nematode species Steinernema feltiae (SF) is highly effective at stopping thrip pupae in this soil stage.

Adding these nematodes to your soil can help get ahead of the problem, and prevent thrip populations from continuing to grow larger.

While you'll likely have to pair SF nematodes with another beneficial predator species for full control, nematodes can still be a powerful ally in attaining a balanced ecosystem that's not overrun by thrips.

Lacewings

It's not the adult lacewings that feed on thrips, but the lacewing larvae when they're young.

Larvae will crawl up and down plants seeking out thrips, aphids, whiteflies, spider mites, mealybugs, caterpillar eggs, and other pests to devour.

They are voracious, and their appetite earns them a spot on the list of friends of gardeners and farmers.

Adult lacewings subsist off of pollen and nectar, so if you'd like them to reproduce and give you future generations of larvae you'll want to provide a diversity of flowers for them to access, and be sure that you always have something flowering in your garden or greenhouse to keep adult lacewings well-fed and reproducing.

Hypoaspis Miles

Amblyseius Swirskii

Measures to Prevent Thrips

Other Ways to Treat Thrip Problems

Final Thoughts...

Looking for ways to control other garden pests naturally? Check out the full guide here.