The smallest European beetle

Photo: Natural History Museum of Denmark

Baranowskiella ehnstromi, a member of the family Ptiliidae (featherwing beetles), is the smallest known beetle species in Europe. It was discovered and described in 1997 by Mikael Sörensson in his home country Sweden. Meanwhile, scientists found the only 0.5mm long animal in Norway, Denmark, Switzerland, Austria and Germany. 

This little creature is as thin as a human hair and on top of that very elusive as it lives only in pores of the parasitic bracket fungus Phellinus conchatus, which grows on goat willow (Salix caprea). It took a while until beetle experts figured out the best way to collect specimens. They collect bracket fungi from willows and let those dry over a dish in the laboratory. The beetles (and all other inhabitants) will move out of the drying fungus and end up in the dish.

Yesterday, researchers from the Zoological State Collection in Munich announced that they retrieved some DNA Barcodes for Baranowskiella ehnstromi. They hope that with the rather simple collection method described above they will be able to collect more individuals to show that the species is actually as widely distributed across Middle Europe as its fungal host. The fact that they now have reference DNA Barcodes will make future species determination much easier as it won't require a Ptiliidae specialist.