A contribution towards a revision of West Palaearctic Procladius Skuse (Diptera:Chironomidae)

The genus Procladius is in great need of revision. Such an exercise would be fraught with many uncertainties. Those species characterized by having marked wings may have the markings extremely faint and perhaps even absent. The spur of the gonostylus is variable in length and shape, in the pharate adult rotated more vertically and compressed, so that association with pupal structure is not simple. It appears that the spur is extended hydraulically on eclosion, perhaps to a variable degree. The one character that appears to remain constant is the phallapodeme toothed at apex or not, but that just separates the subgenus Holotanypus into two groups. Even the type species of s.g. Holotanypus, P. (H.) culiciformis (Linnaeus) is not keyed in Langton & Pinder (2007), though recorded for Britain, because the authors were unable to find a clear separation from P. (H.) choreus (Meigen). We here provide a key to the pupal exuviae of subgenus Holotanypus that are now known to us as a step towards a generic revision1. Terminology as in Langton (1991).