Perlodes microcephalus

larva  

  -    . . .

  - Order Plecoptera
  - Family Perlodidae
  - Genus Perlodes
  - Species microcephalus  

I found this big Perlodes larvae under a stone in a cold and unpolluted alpine creek.




Perlodes are medium to large stoneflies, this one was 3 cm. including cerci and antemnas




Typical straight external border of the wing case of a perlodes (as opposed to the rounded ones of the Perlidae family)




The absence of branched gills underneath and on the side of the thorax is a key difference distinguishing the Perlodes from the Perlidae genus.