Drie maal is scheepsrecht, de zweefvlieg Chalcosyrphus eunotus terug op de Nederlandse lijst (Diptera: Syrphidae)

Three times does the trick, Chalcosyrphus eunotus back on the species list of the Netherlands (Diptera: Syrphidae) Chalcosyrphus eunotus (Loew, 1873) has already been reported twice for the Netherlands, in 1958 and 1965. Both times re-examination of the specimens showed that it concerned Criorhina pachymera (Van der Goot 1969, Van der Linden 1988). On April 6, 2000 a male C. eunotus was caught near Elsloo (Limburg, the Netherlands). The distribution, flight period and habitat of C. eunotus are summarised, and many new European records are given. Chalcosyrphus eunotus usually occurs in deciduous forests (Quercus- Fraxinus-Ulmus) and is often found along the edges of small streams running through the forest (Speight 2000; this paper). The larvae were found in logs and below bark of logs laying in flowing water (Speight 2000). Chalcosyrphus eunotus appears to be underrecorded. There are many recent records and once caught in an area, often more records follow. In southern France five specimens were caught in a Malaise-trap (pers. com. J.-P. Sarthou). It can therefore be expected that investigations in suitable habitats will yield much more records.