XGS,

I'm totally new to bamboo, but I am a bug person. You could have either centipedes or millipedes, but the difference is quite important.

Centipedes are carnivorus hunters that would only be present (in the numbers you're talking about) if there were other small invertebrates to eat. So basically, your bamboo might have another pest that the centipedes are actually eating for you, so don't kill them.

Millipedes are herbivores but that being said, most species enjoy nice soft foods like veggies or rotting plant material. If they are actually damaging an otherwise healthy plant (especially something as tough as bamboo) I will be very shocked.

I would re-pot and carefully wash away the dirt from the rhizome so you can see if any of the roots are rotting. Just my 2 cents, I'm sure others with more bamboo experience can help you out with the plant side of things.

I've had them(light brown small ones), and they do indeed seem to harm my potted bamboo, and bananas. Not sure why, but the plants look like crap that had them.

I've also had them and they do harm the plants they infest. I think what happens is that a millipede looks for a place to deposit her eggs. The eggs hatch and the offspring begin eating and growing. Because they are in a confined space (a pot), they eventually run out of food and turn on the roots for food. Also, when it is dark they will start swarming out of the pots. Very freaky!

Submerging the pots in water for 24 hours will force a lot of them out of the soil. I am still trying to find a good insecticide for them that will not kill the plant. The best I've found is a poison impregnated diatomaceous earth.