Psarus abdominalis (Fabricius)
Threatened at the European level. This is one of the few species of Diptera so far included on any continental European "Red List" (see Andersson et al. 1987). Not only is this species evidently a victim of forest clearance and forest management throughout Western Europe, it is such an unmistakeable insect it is highly unlikely that its presence would go undetected. The fact that it is the only species in its genus (and subtribe) and is endemic to Europe makes its status of greater significance. If ever there were a syrphid which required special protection measures to be taken to ensure its survival in Europe then P. abdominalis is it (Speight 2010).
Deforestation and management throughout Western Europe.
Syrphus abdominalis Fabricius, 1794: 307.
Psarus arcuatus Macquart, 1834: exp. pls. 7.
Musca coalescens Geoffroy, 1785: 486.
Musca abdominalis Turton, 1801: 650.
Psarus is a monotypic genus and P. abdominalis is a highly distinctive insect. The only other European syrphid it resembles even remotely is the male of Pyrophaena granditarsis, which has likewise a bright orange-red abdomen (Speight 2010).
Flowers visited: Geranium sanguineum (Speight 2010).
Flight period: from end of May to July (Speight 2010).
Psarus in a monotypic genus confined to Europe. It ranges from southern Sweden (extinct?) south through the Netherlands (extinct?) and Belgium (extinct?) to central France (recent records from Rhine valley and Paris basin); from Brittany eastwards through central Europe (Germany - Rhine valley, Switzerland - extinct?) to Roumania and European parts of Russia; Italy and the former Yugoslavia.
Adult flies along woodland paths and at the edge of woodland. Males have been seen sitting in the sun on the end of dead branches of trackside trees, at 2 m or more from the ground, returning to particular branches repeatedly (M. Hauser, pers.comm.). On hot days, after rain, this species visits temporary puddles of water on forest tracks, to drink (M. de C. Williams, pers.comm.) (from Speight 2010).
Preferred environment: well-drained Quercus forest with mature/overmature trees and a diverse ground
flora (Speight 2010).