Het onderscheid tussen Aeshna subarctica Walker en A. juncea (L.) in Nederland

This article reviews and illustrates the major characters on which Aeshna subarctica and A. juncea can be separated in the field. Variation and reliability of fourteen features was investigated by screening 24 adults of A. subarctica and 22 adults of A. juncea, all originating from The Netherlands. Most characters showed variation, which could result in identification errors if too few of them are taken into account. However, within individuals on average only one or two features (range 0-4) did not fit the description of the species involved. Therefore, identification is straightforward as long as enough characters are applied. Despite apparent differences between the two species, flight identification should be seen as a rather unreliable method.