Larvae of the burrowing mayflies live in U shaped tunnels. They move water through the tunnel with rhymethic action of the gills on the abdomen. They filter out food particles from the water moving through the tunnel. They are active in winter althought the activity is reduced. Sediments are warmer in winter probably close to 46 to maybe 50F depending on location of tunnels. The larvae that I've had can be fairly active swimmers in 40F water. Some fish especially yellow perch can probably sense the water moving or upwelling through the tunnels. YP are known to use their snout to rout out mayflies and midge larvae from the bottom sediments.
Last edited by Bill Cody; 11/24/11 03:41 PM.
