system
Given the following post, respond as if you're commenting on Reddit:
human
[Starship Troopers] What do the bugs eat?

Each bug is a huge apex predator and they apparently reproduce by the millions.

So what do they all eat? There can't possibly be an ecosystem that can sustain so many hungry bugs.

And yet they fight humans in a desert planet. The kind of place that has a very low carrying capacity, shouldn't most bugs just starve to death?

The bugs are too big and powerful to survive on moss or vegetable sources, they have to be carnivores. And even then, they probably spend most of their awake time eating.
gpt
According to the prequel comics they feed on themselves. Each species excluding brain and queen bugs fight each other for dominance before breeding and consuming the dead. We do see the god bug eating an arachnid warrior so it's possible they breed en masse and simply fight before starvation weakens them. Making each bug seen on screen only a few days old at most. A more likely answer is that the bugs farm a livestock species like the servant drones that can eat fungus or lichen grown deep in the hives and the larger warrior species eat them as well as their own dead.