New species discovered - Scientists call for woodland management rethink

[Orstio]

http://www.everything-science.com/index.php?option=com_content&task=view&id=128&Itemid=2

Evasive research subjects

“When we researchers go into the forest we really need the same kind of nose as these flies to sniff out the sap runs under the bark, because they’re often not visible.” Someone like Dr Frank Dziock, whose work focuses on these sap-dependent hover flies, cannot simply lie down in a lush flower meadow and wait to see what comes buzzing along, for these insects live hidden within the woods in very special old trees. They live on micro-organisms which are only found in tree sap – in contrast to their more widely known relatives. Although many of the other species of hover flies may be mistaken for wasps because of their black and yellow colouring, they cannot sting. Their larvae are actually very useful, as they consume large numbers of aphids. Around 450 different species of hover fly are found in Germany and they have a wide variety of dietary habits.