Tag Archives: snow

Snow fly

If you’re out on a nature walk today, keep your eyes peeled for snow flies. These are essentially wingless crane flies loaded with antifreeze. This one is a male Chionea scita, I believe. Not much is known about these insects, although there is speculation that at least some members of the genus hang out in rodent burrows eating feces. (Don’t judge.) Please see “The crane fly genus Chionea in North America” (Byers 1983) for more details.

You might note that it has halteres, which is interesting because these are organs used in flight (they are modified wings … which is why flies only have one pair of wings). Would be fun to figure out whether snow fly halteres still work, though that would have to be inferred by anatomy and maybe some electrophysiological tricks. Or perhaps they serve a new function. To see photographs of some flies that have lost their halteres, check out the Braulidae (bee parasites) or Hippoboscidae ovinus (sheep ked). I love wingless flies. Did a presentation on them when I took entomology during high school … and have been creeped out and impressed by them ever since.

Colin Purrington Photography: Insects &emdash; snow-fly

Skunk cabbages in snow

Photograph of Eastern skunk cabbage (Symplocarpus foetidus) covered with snow.  I didn’t confirm with a thermometer, but these are famous for heating themselves up, maintaining 35 °C (95 °F) internal temperature even when outside air is below freezing.  Heat helps volatilize the awful smell, which can be attractive to flies and beetles, but also creates a hot “room” inside the curved leaf (spathe) that surrounds the inflorescence on the spadix (hidden from view at this angle).  But a more likely hypothesis of why this ability evolved is that thermoregulation protects pollen tube growth and female reproductive structures from frost damage. Either way, one of my favorite plants. Growing in the Crum Woods, Swarthmore, Pennsylvania.

colin purrington photography: plants &emdash; Eastern skunk cabbages (Symplocarpus foetidus) in snow.  Crum Woods, Swarthmore College, Pennsylvania. They actually heat up to provide warm environments for flies, their primary pollinators.