Nieuwe waarnemingen aan sprinkhanen en krekels in Nederland (Orthoptera)

New records of grasshoppers and allied insects in the Netherlands (Orthoptera) In this paper a summary is given of the new records on Dutch Orthoptera since Kleukers et al. (1997). The field work in the Orthoptera Mapping Scheme (1990- 1995) covered almost all the country, on a scale of 5x5km-squares. Nevertheless many new records were gathered in the following period (1996-2002). The most spectacular discovery was that of a large population of Gamposcleis glabra on the northern Veluwe (Berg et al. 2000). The species was thought to be extinct in the Netherlands. On the same site one of the biggest populations of Ephippiger ephippiger in northwestern Europa occurs. Phaneroptera falcata and Conocephalus discolor show a clear range expansion, of which that of Phaneroptera falcata is very spectacular (fig. 3). Metrioptera roeselii and Chrysochraon dispar are probably also expanding their range, although this is less evident. Chrysochraon dispar seems to be colonizing a new habitat (for the Netherlands): rough vegetation in the newly created nature development reserves along the Dutch rivers. A puzzling fact is the discovery of 19 small populations of Stenobothrus lineatus on the Utrechtse Heuvelrug, a large Pleistocene hill, in the central part of the Netherlands. In the past the area has been surveyed quite extensively but only one small population was found in 1993. Stenobothrus lineatus is not known for its migrational tendencies, but it also seems improbable that so many populations have always been overlooked in the past. Meconema meridionale and Oecanthus pellucens have probably been introduced in the Netherlands by cars of tourists. Meconema meridionale has established several large populations and has been found on a few new localities in the period 1996-2002. Oecanthus pellucens was found for the first time in the Netherlands in Delft in 1995. After that the species was found on several localities spread over the country, probably all to be traced back to passive transportation by tourists. Surprisingly, in 2002 three males were found in Delft, indicating a breeding population. It is to be expected that Oecanthus pellucens will reach the Netherlands ‘the natural way’ along the valley of the river Rhine, where it is has already pushed northward to Duisburg (Germany), 75 km from the Dutch border. Despite all these new records, not all is well in grasshopper country. We have indications that the decline of the really vulnerable species is still ongoing. For example, Decticus verrucivorus seems to have disappeared from two of the remaining four localities. Apart from the new distribution data, much progress is made in the field of Orthoptera conservation. The publication of Kleukers et al. (1997) has paved the way for inclusion of Orthoptera in Dutch nature conservation policy. This insect group now plays a role in many major environmental projects and publications (Kleukers 2001). Furthermore it proved to be possible to convince nature managers to actively protect endangered species like Decticus verrucivorus.