Potential thrips issue in a terrarium
 

Hi folks,

I have just thrown away two of my houseplants which I barely looked at for months and were heavily infested with thrips. They were standing in the same room with my terrarium with miniature orchids. I am now freaking out that hell is going to break loose, since the thrips are tiny, barely visible and once you spot the symptoms it's usually too late.

I am thinking about spraying everything with insecticide. Do you think it's a good idea?

To be honest, I am not sure if thrips can even infest orchids, they never did infest any of my Phrags or Brassavola.

But in this terrarium I have tiny, sensitive beauties: Pleurotallids (A few Lepanthes, Restrepia, Anathallis, Pleurothallis, Trisetella), a bunch of Angraecoids, Den. cuthbertsonii hybrid, D. hekouense, Sophronitis, Neofinetia, Mediocalcar, Leptotes... The issue may also be that some of these do not like being treated with chemicals, like Pleurothallids and D. cuthbertsonii-types.

Should I be worried? I did a close inspection of everything today, and I see no trace of infestation...yet.

Thrips definitely can infest orchids. . Since you aren't seeing any evidence of infestation in the terrarium, if it were mine, I would just be watching carefully, not rushing to treat.

If it is to any help at all, my pinguiculas decimated the thrips population in my terrarium!

One way to eliminate pests is to submerge the plant completely, pot also, in water with a very small amount of dish soap. Use a weight to be sure the plant stays under water. Do this for 4-12 hours. It drowns the eggs too.

Thanks a lot for your help!

In the meantime, I realized that there is an ideal way to tackle this issue without resorting to pesticides, at least here in Germany. I ordered a predatory mite Neoseiulus cucumeris which preys on thrips from one vendor, and I placed the bag inside the terrarium. These are intended for larger spaces, so after a week, these mites were everywhere and, if there were any thrips, they surely did not survive the invasion. So, still no sign of them!