Thrips

Thrips

If your plant becomes infected with thrips, you need to act fast! These little insects multiply quickly and can do great harm to your houseplant.

SYMPTOMS & IDENTIFICATION

The first sign of thrips that you will usually notice is that your plant’s leaves will start to look a bit dull and unhealthy. You will often see:

  • Paperlike marks

  • Silvery or bronze discoloration

  • Black specks - fecal spots (thrips poo!)

  • Drooping leaves

  • Part of the leaves die

  • Deformed growth

When taking a closer look at your plant, you might find something that looks like this - typically on the underside of the leaves:

Thrips 1

TREATMENT PLAN

1. Isolate the plant - thrips spread really fast!

  • Place the infected plant in a closed room to avoid thrips flying to other plants

  • Make sure to also check all other plants for thrips

2. Wash the plant

  • Place the plant in the shower and rinse the leaves thoroughly with lukewarm water. This will quickly decrease the population (try to avoid getting water on the soil)

  • If it’s possible you can also bring it outside and wash it off with a hose

3. Kill the thrips

  • With pesticide

    • There are several different types of pesticide that can help you kill and manage thrips, just make sure that the one you have/buy does.

    • Treat your plant accordingly to the instructions on the bottle / the package.

  • With neem oil This works best with medium infestations of thrips. If the infestation is bad, consider using an insecticide.

  • Mix 1 quart of lukewarm water, 1 tsp neem oil and 1/2 liquid soap. Shake until all neem oil droplets are gone (neem oil mixes more easily with warm water).

  • Spray the leaves and stem with the solution and pour any excess down into the soil to prevent new eggs from hatching.

  • If the attack is bad, you can mix some insecticide in the neem solution - for extra killing power. Neem oil has a very strong smell, which many find unpleasant. However, the smell will stop as soon as the oil is dry.

Neem oil
  • With thrips predators

    If the infestation is really serious, you could consider using thrips predators.

    • Neoseiulus cucumeris - prey on the eggs and nymphs

    • Minute pirate bug (Orius insidiosus) - eat both eggs, nymphs and adult thrips

    The idea of releasing MORE insects in your home may not feel very pleasant, however, this is actually one of the most effective ways of getting rid of thrips.

Bug

CAN I AVOID THIS FROM HAPPENING AGAIN?

Yes, prevention methods are mainly to keep tight control of all new plants and vegetables entering your home:

  • Put all new houseplants in quarantine before introducing them to the rest of your plants

  • Do regular check-ups on your plants

  • Keep fruit and vegetables away from your plants


QUESTIONS ABOUT THRIPS

HOW BIG ARE THEY? Thrips are tiny and slender little insects, not larger than about 1/25-inch (1 mm) long, sometimes with wings. Thrips come in many different species, even as many as 6000!

WHAT DO THEY EAT? Their main food is plants, which they feast on by puncturing the leaf and sucking up its contents. This is why you often find silvery or bronze-colored scars on leaves where the thrips have been.

DO THEY BITE HUMANS? They can bite us, but it shouldn’t cause any great discomfort. It’s also not very common to get bitten by thrips.

WHERE DID THEY COME FROM? Thrips are common outdoors, so it’s possible that they ended up indoors via another plant that spent some time in the garden. They could also have been brought in by cut flowers, vegetables or fruit, or other plants you just bought.

And, since they can fly, it’s possible they flew in through an open window or door.

CAN THEY FLY? They do fly, but are not very good at it and would probably rather not. However, consider using sticky tape to catch thrips on their way through the air searching for new plants to eat (it is quite uncommon, though, to see thrips come flying through the air).

HOW LONG DO THEY LIVE? After hatching, the small thrip, called a nymph, can be seen walking around on the plant - almost transparent to yellow in color. Adult stage is reached within 8-15 days, and their total lifespan is about 45 days. There may be as many as 12-15 thrips generations per year. Also, the little insect can reproduce asexually - which means they don’t need a mate to multiply.