WHY ARE THERE SO MANY DIFFERENT SPECIES OF SNOW CRANE FLIES?
Sixteen species of Chionea snow flies are now recognized as occurring in North America. Most have ranges somewhat distinct from each other. This reflects, in part, biologists belief that these different species over time diverged from common ancestors. For this to occur, the fly populations had to spread out and then become separated from the parent population. Once they were isolated reproductively, the passage of time along with random changes and different selection pressures eventually results in a lineage of snow flies that could no longer interbreed with the parent stock. This process is called speciation and probably requires long periods of time. WHAT DO SNOW FLIES EAT? Nobody knows. Byers has kept an adult fly for 19 days; the record is 62 days. But adults do not appear to feed on solid foods. It is the larvae that feed heavily and grow and “I have failed at every attempt to rear the insects,” reports Byers. Indirect evidence suggests that those living in rodent burrows feed o
