Mite damage? TINY black dots and yellow leaf

[ceb_010]

Hello!

Newer orchid grower but owner of many other houseplants. I’ve gotten these before on a Pandora jasminoides (bower vine jasmine) and assumed they are mites. I recently found them on my new Rlc. Exotic’s Golden Sun ‘Summertime Sun’ x Brassavola cucullata.

Hard to make out in the photos but the black dots are TINY. They are not depressions on the leaves and almost seem like droppings.. 😬

I don’t see webbings though so maybe mites is a wrong guess? Tiny scale??

As you can see in the photos the leaves turn yellow.

This leaf was new growth. The plant is in a west facing windowsill and does get a decent amount of sun in the late morning and afternoon.

Since I spotted this I’ve been spraying nightly with neem oil.

Thanks in advance!!

[estación seca]

The first photo looks like spider mite damage. They are generally on the undersurface of leaves. The neem oil may have killed them, leaving the damage. If you use the maroon Search feature above you can find lots of posts on spider mites.

If you read the label on neem oil it probably tells you not to use it more often than 2-3 times in a month, because it can clog the pores of plants, too. Nightly is definitely far too often.

Cattleya leads often0 develp miscellaneous black and brown spots that can't be diagnosed. I'm not sure what's causing that one. That is not spider mite damage.

[Shadeflower]

spider mites can be seen.
The damage you are showing is what thrips have been doing to mine and thrips hide really well.

The best time to catch thrips is at 2 am with a torch and a straw. Sneak up to the plant and shine a light on it. Keep a close eye on the surface of the pot. Keep an eye out for anything shiny. Start blowing onto the surface. If anything starts moving that is about half the size of a grain of rice it could very well be thrips.

Thrips can finish their life cycle in as little as 10 days in really hot conditions and their eggs can survive treatments so if it is thrips you have to keep treating the plant.

A lot of thrips live in the substrate so treating the leaves is not enough as it is with spider mites.

[ceb_010]

Thank you! That would make sense I believe I spotted some on other plants. What is the best treatment for them?

[Shadeflower]

that's a good question ceb, I was using pymethrin based insect spray but that wasn't enough.

I don't have the answer on what is easiest or best.

I've resorted to soaking any I find in a bucket of warm water for 10 minutes with a few drops of dishwasher soap added.

Recently I have started addng mineral oil to my bucket too. Basically any oil and mineral oil is a lot cheaper than neem oil.

So this kills any thrips on contact (the soap) the mneral oil adds a pretective layer but can't say if the oil helps or not.

I've still had to repeat this process weekly till no more thrips appear.

I can't even say if my treatment has worked so far. I'm definetely down to just 1 or two here and there but 1 or two can easily multiply and start all over.

It can depend on the species though, I think I had thrips before that were not immune to my thrip poison but the latest ones I've had to really soak the whole pot and orchid in soapy water.

Don't be worried about the orchids absorbing a bit of soapy water - I was - orchids are still flowering so it doesn't harm the orchids. Just rinse off all the soapy water after 10 minutes