Ptychoptera longicauda (Tonnoir, 1919)

Wiberg-Larsen, Peter, Hansen, Søren Birkholm, Rinne, Aki, Viitanen, Esko & Krogh, Paul Henning, 2021, Key to Ptychopteridae (Diptera) larvae of Northern Europe, with notes on distribution and biology, Zootaxa 5039 (2), pp. 179-200 : 194

Ptychoptera longicauda

This species has a southern distribution within the regarded geographical area ( Fig. 5C ) and is recorded in southern U.K, Netherlands, Denmark, southern Sweden, northern Germany and northern Poland ( Zwick 2020). It does not seem to be abundant anywhere, and seems to be local in the U.K. ( Stubbs 1993) and Denmark. Its northern boundary is located at approx. 56.5° latitude with the northern-most record from Öland ( Sweden). Its distributional area extends to middle and southern Europe ( Austria, Czech Republic, Hungary, Slovakia, Slovenia and Switzerland) ( Zwick 2020) and, to the east, into Ukraine (Oboňa et al. 2017).

The larva of this apparently rare species has hitherto been practically unknown; therefore, knowledge of its habitat is limited. Stubbs (1993), however, suggested a preference for calcareous and silty, woodland streams. Records from streams in Denmark point to a preference for small (<2 m wide), fast-flowing streams in woodland areas. Furthermore, these streams were all situated in calcareous moraine areas. At one of the sites, where larvae were abundant, these were primarily found at moderate velocity, in the bottom of fine sand with detritus and at depths of approx. 10 cm.

Although the data are rather limited, the flight period seems to occur later than for the other two lotic species, P. lacustris and P. paludosa , i.e. primarily from July to August, with only few records in June and September (see also Stubbs 1993).

Figures

FIGURE 5. Distribution of Ptychoptera species within the geographical area defined as Northern Europe, delineated by grey line. A. Ptychoptera albimana; B. P. lacustris; C. P. longicauda; D. P. paludosa. Blue dots show specific records, blue raster indicates confirmed but unspecified presence and red raster indicates likely presence.