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The
Periscelididae is a small family of acalyptrate flies, but its
limits have recently been disputed. In the present checklist the
family is treated in the restricted sense, without Stenomicra
Coquillett, 1900 which is considered to belong to the separate
family Stenomicridae Papp, 1984. The adults of European species are
small flies (2.0-4.0 mm) with brownish thorax; abdomen and legs
yellow with dark bands. Arista pectinate. Wing: costal vein without
breaks, not reaching further than junction of R4+5, subcosta
vestigial apically. They occur very locally, from lowlands to lower
mountain altitudes, on and around diseased or wounded deciduous
trees (species of Ulmus, Quercus,
Morus and
Salicaceae) where they suck flowing sap mostly at the height of the
tree canopy, and so they are only rarely collected by the usual
methods (Bächli
et al. 2006). The larva and puparium are dorsoventrally
flattened, each segment with a transverse row of spinulose processes
(Papp
1995). The larva feeds on fresh flowing sap on the surface of
bark (Papp
1998).
According to the present concept, the Periscelididae comprise five
genera with less than fifty described species. In Europe, there are
only four species in a single genus
Periscelis Loew, 1858.
Three
species were listed in the ECV1 (Máca
2006),
and since then one more species, Periscelis nigra Zetterstedt,1860,
has been added (Roháček
2009),
thus all four
European species are listed in the present checklist: three from the Czech
Republic (two from both Bohemia and Moravia) and three from Slovakia.
For the identification of European species the paper by Duda (1934)
is still fundamental, and the manual by Mathis and Papp (1998)
provides useful new information.
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