Thrip control in Europe?

[naturalistSean]

Thanks for the replies all! I like the idea of neem oil but to be honest I've had limited success with it on other non-orchid plants in the past.

The paph I mentioned was due for watering so today I submerged it (I find this difficult with bark, it floats away). 5-10 minutes later I noticed several thrips climbing away from where water pooled at the base of the leaves. I've a number of plants in spike now so I'll want to take swift action to control these tiny beasties.

I'll mention that control of insecticides in Europe seems at least partially tied to concern for dwindling honey bee populations. It's a concern I share. Generally I'm of the opinion that there are too many chemical pesticides used in the world although of course it is mostly in agriculture and outdoor situations. Given the small amount of insecticides used on indoor orchids I don't think this is where the problem is.

[estación seca]

Originally Posted by naturalistSean

The paph I mentioned was due for watering so today I submerged it (I find this difficult with bark, it floats away).

When I soak plants growing in floating medium I invert them quickly into a container just wide enough the pot can't turn over while submerged. Less medium comes out of the pot.

For example, this Acorus came with scale:

[Shadeflower]

So I wanted to update that my thrip treatment is coming along.

I've gone from spotting about 200 per week down to just a handful this past week.

I looked around and came across a better (most important cheap) pesticide than the permethrin based one I have been using.

This new one promises 4 weeks leaf protection so off to get this stuff to have on standby when I spot the next one, it contains deltamethrin

Attention Required! | Cloudflare

Not sure if it is a UK product or if it available in the rest of europe.

I'm going to try it and see.

Beats having to wash each orchid individually (and changing the orchid bath for each orchid). I got round to taking a picture of one of mine enjoying its bubble bath.

[tmoney]

thankfully the black thrips haven’t shown up inside on our orchids, but this year seemed particularly bad for them. we had one balcony plant that was attacked by them and by the time it was found the plant had lost all of its 6 growing shoots. i let it go for a couple days longer for several reasons, and by that time it was pretty much a gonner. now the plant is 3 measly half-dead stalks that sitting in our apartment hallway.

edit to include our non effective treatment! i am a huge advocate of no chemicals, so soap and water is the usual approach. chopped the really infested parts and disposed carefully. then a strong mix of soap, much more than usual, and stayed it like crazy. washed the media as much as realistically is possible with the same. retreated the same way about a week later. now it’s in the state described above and we are waiting to see whether we keep trying or just throw it. i took several sets of cutting from this plant in the spring, so it’s ok if we lose this mom plant, the cuttings are at school and are looking really good.

also another of our biology teachers takes our bio lab experimental geranium collection home over the summers. this yeah she lost all of them due to thrips, a major setback. she lives in the netherlands and said she just couldn’t get ahead of them and by the time she saw them it was too late. so now all of our personal geraniums have been chopped (including one that is a true specimen plant) to get cuttings for this year and hopefully start to replenish our group without spending our precious petty cash

[Shadeflower]

hey T,
I could have sworn I saw one outside on one of my chicken coops.
I was like nah, that can't be but maybe I did just pick up a local thrip variety at mine.

So I mentioned rcently that I have been adding a teaspoon of white mineral oil to the drop of washing up liquid I've been adding to the bath above and I think the oil has helped.

Been 2 days, no thrip spotted yet but they have sort of weekly life cycles so I need to keep checking.

The weird thing is they have hardly done any damage that I can see. The main issues the infected plants have are not able to grow new growths to their new potential and root growth is stunted.

Also damage does not appear for 2 months after the thrips do the damage! So by the time you spot thrip damage they have already had 2 months to breed and hide all over.

That is one thing I am finding out now. On some that I am certain I have eliminated the thrips, brown damage is appearing on the leaves, weeks later. It just did not show and is actually hard to spot in sunlight too. It's easier to notice with a torch at night.

I have lost one orchid to thrips by now but that one was just a tiny little backbulb, athough it probably would have made it without thrips.

I actually took the bulb, cleaned it, stuck it in a sealed jar and guess what, a week later there was a thrip inside the sealed jar sucking on the bulb!

[My Green Pets]

there are predatory mites that specialize in eating thrips eggs and larvae. i have had excellent results using predatory mites for spider mites and i haven't seen a thrips in well over two months either. if these are available in europe i highly recommend them. the only catch is that conditions must be ideal for the predators; each species requires specific humidity and temperature to thrive.

[naturalistSean]

Thank you for the ongoing discussion.

Strangely the thrips I had seem to have disappeared. I don't really understand it and expect them to return, or rather for the eggs, larvae and pupae to appear as adults later. I'll keep a close eye on the situation. I've discovered that a systemic insecticide is available here called Acetamiprid under the product name Careo. Should this thrip problem come back I'll consider using it.

I like the idea of using predatory mites but my environmental conditions are all over the place.

I'm surprised to read that thrip damage doesn't show until later. My experience with these little black beasts appears to be a bit different. Several times I've found a thrip, killed it with my finger, and within a few days damage is apparent in the precise spot I found it. For example this happened once on an emerging flower spike and another time on an otherwise immaculate leaf.

As an aside, thank you Shadeflower for your orchid suggestions on another thread! Some of the plants I acquired were based on your input and I'm happy to report that the Dtps. Tzu Chiang Sapphire has started developing flower spikes.

[Shadeflower]

good to hear shawn.

My battle continues. This one was repotted, new susbtrate.

And...

more resilient than cockroaches for sure..

This is magnified, the small lines on the picture are micro scratches in the plastic

[naturalistSean]

One would be forgiven for confusing that with a very small beetle. For how small they are it is remarkable to me how much damage one individual thrip can cause! Best of luck getting the little suckers under control.