The Isophya species of Central and Western Europe (Orthoptera: Tettigonioidea: Phaneropteridae)

rope (Heller et al. 1998). In this region, it is second with regard to species richness after the closely related genus Poecilimon, but first with regard to the difficulties to identify the species. Already in naming the genus probably Brunner von Wattenwyl (1878: 59) had this characteristic feature in mind: he translated the Greek parts of the name ‘isos’ into Latin ‘aequalis’ (equal, similar) and ‘phyo’ into ‘gigno’ (to beget, to father). Both genera belong to the family Phaneropteridae and lack internal sclerotized male genital organs, which are very helpful for species identification in other bush-cricket families. The shape of the male cerci, another character often used for identification, is quite simple and does not show an elaborate shape as in some Poecilimon species. The identification of Isophya species therefore was based mainly on subtle differences in the shape of cerci, pronotum, tegmina and ovipositor. Thus it is not surprising, that even in Western and Central Europe nearly half of the currently recognised species have not been described before the beginning of the second half of the last century (see below). On the other hand, some of the species described during the 19 century have not been recognised as valid species until recently. The study of the calling songs and stridulatory files as additional species-specific characters, whose significance is well known from other Orthoptera, was first applied to the genus Isophya by Zhantiev & Dubrovin (1977), later to the Central European forms by Heller (1988). One important finding was that what was con-