mozenrath87-deactivated20150623 asked:
bogleech answered:
Many land arthropods prefer the cold! We just don’t notice them as much. Just a couple of the most dramatic examples:
“Snow flies” are cold-loving crane flies without any wings, since they like it SO cold, flying would expend enough energy to freeze them to death in mid-air. The adults don’t feed, but the larvae eat algae, moss and lichens.
Snow scorpionflies are Mecoptera, like the insect I just posted last night, with the same adaptations as the snow fly. Fleas are actually ultra-specialized Mecoptera themselves, so it’s thought that maybe a wingless, cold-loving scorpionfly like this could have been the ancestral flea - they could have started snuggling with mammals for warmth and soon adapted to feed on blood.
Snow fleas are actually any one of several springtails that enjoy ice and snow. Springtails eat any organic matter, especially pollen, algae and bacterial colonies, and are so basal they may not even qualify as true insects, but their own older group of hexapoda.
Ice crawlers have one of the saddest and most interesting backgrounds. They’re the only surviving members of an insect group called the Grylloblattidae, which were a dominant group in the early years of terrestrial ecosystems, before plants had even evolved fruits or flowers. As they were out-competed by the rapid spread of bees, flies and beetles in association with flowering plants, they dwindled away and now their only remaining members live exclusively on the outer, slowly melting edges of glaciers, where no other insect can bother them.
If an ice crawler so much as crawls onto your open palm, the heat radiating off your skin will kill it in seconds.
While not adapted as extremely as these others, another dramatic cold-loving insect is the “bone skipper.” These flies are most active when there’s snow on the ground, but it’s still warm enough that they can get away with flying. Like more common warm-weather blowflies and flesh flies, they feed on carrion, but they especially prefer the carcasses of very large mammals with broken-open bones, where they deposit most of their eggs.
Bone skippers were once wildly common, and probably much moreso before humans caused the mass extinction of megafauna. By the mid-1800’s, overhunting of their remaining food sources was believed to have driven them extinct, as none were recorded again until 2009!
It’s thought their remaining population went unnoticed for so long simply because not many people are looking for insects in the wintertime. Plus, they’re nocturnal, which is very rare for true flies!
One last thing I’ll mention is that some species of velvet worm also like it cold, and die if they get too warm. They naturally live in chilly temperate forests at high altitudes.
photo sources in order:
http://thedragonflywoman.com/2010/12/24/whitechristmas/
http://bugguide.net/node/view/94116/bgpage
http://www.cantongeorgiapestcontrol.com/pest-control-in-the-snow-canton-termite-and-pest-control/
http://www.livescience.com/37965-mythical-corpse-eating-fly.html
One more cold-adapted bug that I personally think is cool is the Antarctic Midge.
(Image from Denlinger Lab, OARDC. Larvae on the left, adult on the right)
They can literally be found on the South Pole, and are the only insect native to Antarctica. These guys live two years as larvae before getting enough nutrients to pupate to turn into adults. Like most of the other examples, they’re flightless to conserve heat.
For some reason, they have effectively no junk DNA, which somehow (?) helps them survive in this particularly barren environment.
cucumber-s
