Friday, February 02, 2007

The snow springtail

One of the commonest arthropods in the British Isles is the springtail Entomobrya nivalis, found almost everywhere summer or winter. At only 2mm long it is not easy to photograph, especially as they are restless creatures.

They do, however, like a bit of sunshine and this one was running about on the plastic rim of Wbx in company with other springtails. The specific name 'nivalis' means 'of the snow' and does, I imagine, refer to the propensity of this species to turn up on snow fields. Apparently it can survive freezing conditions because its body contains thermal hysteresis proteins and a cocktail of other chemicals, but the trick is not well understood.

Identification of springtails is not easy, but there is a wonderful 260-page test key by the late Steve Hopkin that was issued by the Field Studies Council. Let's hope it is turned into a proper book one day.

No comments: