ABSTRACT
A general rule has been proposed and is often discussed concerning the relationship between species diversity and the number of individual organisms in any given habitat. The temperature can become uncomfortably warm on the tundra during the long summer days, so the visitor is sometimes forced to choose between uncomfortably warm clothing or being bitten by swarms of bloodsucking flies and midges. Insects must adjust their life cycles to these harsh conditions, and members of the Diptera account for the overwhelming proportion of the aquatic insects present. Regardless of what happens to the surface vegetation, below the pools of water during the summer is a permanent layer of ice. Several species in the subclass Arthropleona, class Collembola, have been called "snow fleas" because they are small, jump, and live on the surface of snow.
