I got out my handy home remedy book and here are some ideas. I haven't had the opportunity to use any of them lucky me.

1 tablespoon Dr Brommer's Pepperment Soap liquid in 2 cups water, spray on the plants,in your case coco shells.

1 tablespoon apple cider vinegar in one cup water, mix and put in low jar near where they are for a few days. They will be attracted by the sweet smell and drown

Mix 1/2 cup Vodka and 1 1/2 cups water, spray on the plants (coco beans) in the cool of the day.

It is worth a try.

Do you know that the coco beans are poisiones to dogs?

Thanks for getting out your book!
I don't know what they are, but through Googling them I suspect they may be mold gnats... I think identifying them is the first step to getting rid of them. I also think their larvae is eating my plant roots.
I knew chocolate is poisonous to (some) dogs, but never put the cocoa bean/chocolate connection together. I used to have a dog who loved to eat fresh ones.. he never got sick.
If anyone has any ideas on what these little buggers could be, please tell me!

Sound like you have fungus gnats, or related insect, that live in moist, moldy, organic material. Cocoa shell mulch has a reputation for getting moldy, especially if it is applied too thick and/or stays wet all the time. If the mulch looks moldy, I would consider either turning it and thinning it out or removing it. Taking away the insects home and food source would seem like the best way to deal with the problem.

I have the same problem, definitely a mold and it's in a shaded area. I'm going to try some of the remedies listed above. Thanks!