Mesembs under mite attack?

[mmcavall]

Maybe is just the wrong climate, too hot, too wet…but I’m having some problems with my Mesembs.

It looks like some kind of mite (?). Can anyone give me some advice?


Plants with few symptoms: Pleiospilos compactus, Pleiospilos bolusii, Nananthus wilmaniae (display kind of a burnt damage on the top of the leaves)

P. bolusii:


P. compactus:




Nananthus:



Plants severely damaged: Glottiphyllum pygmaeum, Glottiphyllum peersii (some plants already gone forever…).

G. pygmaeum:




This one is broken (maybe another problem):


G. peersii:








This is not happening with all species:
Plants that are fine, no symptoms: Pleiospilos nelli, Cerochlamys pachyphylla, Marlothistella uniondalensis, Schwantesia loeschiana , Schwantesia herrei, Tanquana prismatica

Any advice is much welcomed. Thanks!

[jfabiao]

It looks like mite damage indeed, and you can see some red dots on the last pictures that can be the little beasts. Do you have a good magnifying glass? You could probably identify them that way, they are reddish/orangeish/yellowish and slow moving.

As for solutions, you are past the prevention stage. Try abamectin, it works well for me (so far) but follow the instructions carefully, you don't want to build resistance on your mite strain faster than what they will do by themselves.

That type of mites thrives in hot and dry conditions, you must do something to your growing conditions to prevent it from happening.

[mmcavall]

Thanks JFabiao, I've just applied Pirate (CLORFENAPIR), following the recomendations. They may need some weeks to look better, don't they?
Yes, it is hot and dry, but it is dry only in the greenhouse because they are Mesembs and I need to keep them dry...outside is very wet, raining a lot these days...anyway, it is hot.
I have never had problems with mites, this is the first time, and it happened only with the Mesembs and maybe an Aeonium...

Thanks for replying.

[jfabiao]

The damage tissue won't recover, but the plants will grow over it. You should see improvement in the new growth.

[mmcavall]

ok, thanks! I've applied only in half of the damaged plants, because I was afraid about any indesirable side effect. But apparently nothing happened, and nothing will really happens to the plants, since the product was developed for plants and I followed the specifications. So probably tomorrow morning I'll appply in the other half of the plants.
One question: should I apply the product in the Mesembs that apparently dont have any damage, as a preventive action? Or it is not a good idea?

Thanks again

[jfabiao]

I would spray all the plants in that particular location as a preventive measure. Mites are surprisingly mobile for such a slow moving bug: in my tightly packed greenhouse, plants will randomly show signs of being attacked, not the just the ones adjacent to those previously affected.

[mmcavall]

Ok, thanks for your advice!

[mmcavall]

They look much better now, just five days after spraying the acaricide. I guess they were under severe attack!

[greenknight]

By the time you see mite damage, it's a severe infestation - there can be a few mites and you'd never know it. That's why you should always assume the surrounding plants are infested as well.