A new locality for Calopteryx splendens (Harr.) in The Netherlands (Zygoptera: Calopterygidae)

In The Netherlands the continuous decline of the relative abundance of C. splendens (cf. J, VAN TOL & D.C. GE1JSKES, 1981, Nieuwsbr. EIS-Ned. 10; 47-53) means a decrease from 51 to 16 UTM-grid records since 1950. It is worth noting, therefore, that 7 $ and 4$ were recorded, June 20, 1983, on the Bielheimerbeek, Gelderland prov., UTM co-ordinates 32 ULC 1657. The Bielheimerbeek is a canalized brook, about 7 m wide, and up to 1 m deep. On June 20, 1983 the current speed was 15 cm/sec and the Secchi-clearness was 30 cm. The waterdepth at the inner bend of the brook was 50 cm. The vegetation recorded at this locality consisted of Sagittaria sagittifolia (5% cover, linear leaves only), filamentous algae (5%), Nuphar lutea (+), Potamogeton pectinatus (+), Phalaris arundinacea (+), and Glyceria maxima (+'.