BCSS - Forum

Hello all,

I just discovered in the substrate of my seedlings the following insects/spiders (???? I can't see).


Sorry for the very bad quality of the photos but they are very small and always moving. However, you can see them with your own eyes, particularly when the light reflects on their abdomen, so I think they are too big to be red spider mites, or at least not the common ones. I would say they are less than a half of millimeter long, maybe less.

Do you know what they are? Are they dangerous for my seedlings? How may I kill them?

Thank you for your help.

I don't know for sure but either way you will have to assume they are Red Spider Mites. So you'll have to spray them.

Have a look here for possible solutions.

viewtopic.php?f=1&t=166990&hilit=red+spider+mite

Rapid movements tend to indicate predators. They might well be beneficial beasties. If you can see them without a lens, then they are not red spider mite.

They're too big and too red for red spider mites. 'Always moving' sounds more like predatory mites. They don't look like velvet mites (predatory, common in the UK in hot weather). I'd want more of an ID before spraying them - they may be beneficial.

Hello habanerocat,

Thank you for your answer. As I said, I don't think they are Red Spider Mites (or at least not the common ones) because they are too big: it is nearly impossible to see Red Spider Mites with your own eyes, only their damage, and in my case I can distinguish these pests with my eyes. Moreover, I already encountered Red Spider Mites in my collection in the past and they don't fit. Finally, my seedlings do not show the symptoms consecutive to an attack of Red Spider Mites although these pests are numerous in my pots.

Anyway, I suppose that they are spiders and not insects so I will try an acaricide if nobody can tell me who they are.

Have a good day.

Thank you Terry and Mike.

Yes I agree, I wouldn't like to spray them if they are not dangerous, that's why I'm asking for their ID first. Their movements are not that rapid, but they are always walking...

That said, and I don't know if the two facts are related, but look at the skin of these Dinteranthus vanzylii 'Emerald' from MSG 3183 seeds. I don't know what their disease is, these little beasts may be for nothing, but I wonder...

I agree with Terry - predatory mites.

Mafate79 wrote: ↑Thu Nov 08, 2018 9:57 am ...I just discovered in the substrate of my seedlings the following insects/spiders (???? I can't see).

To me they look like Ladybugs or Ladybird Beetles. Coccinellidae

Hello all,

First, thank you for your answers. After a long search on the web, I think that I finally found who they are: a sort of mite which order is named Oribatida (see here).

You can see more photos here. They seem to fit with mine.

The bad news is that, as said on Wikipedia, all the stages after the prelarva feed on a wide variety of material including living and dead plant and fungal material, lichens and carrion; So it seems that my Mesemb seedlings may be endangered and that I will spray them tonight with an acaricide, and I hope that the one I use to kill red spider mites will be effective against them too.

You are correct they are Oribatid mites, very common if you look for them hard enough. They won’t eat your seedlings, there are plenty in my seedling trays. Leave them be, and relax