How do net-building caddisfly larvae catch food in running water?

Net-building caddisfly larvae catch food in running water by constructing funnel-like webs between stones. These larvae produce silk from glands located on their lower lip (labium) to create these structures, which serve to trap food particles as water flows through them.1

While some caddisfly species are free-living or construct protective cases, the net-forming larvae utilize these specialized webs to capture their prey or organic debris. This behavior is a key adaptation for their survival in aquatic environments, allowing them to effectively exploit the resources carried by the current.12