Vier Dekaden Weberknechtforschung mit dem 64. Band der ‚Tierwelt Deutschlands‘ – Rückblick, aktueller Stand und Ausblick

Abstract

A short history of the Opiliones volume in ‘Die Tierwelt Deutschlands’ published by Martens (1978) is presented. The area under consideration comprises Central Europe expanded by large parts of Scandinavia, the British Isles, non-Mediterranean France, Benelux, the complete Alps and in the south-east those parts of Romania and Croatia whose fauna was sufficiently well known. Additions and changes which appeared since 1978 are highlighted: new species discovered in this area, taxonomic changes, important distributional records, as well as changes of faunal composition due to human-mediated influences and climate change are addressed. Perspectives for further research concern faunal inventory especially in the Southern Alps, ecological studies, control of faunal change dynamics and morphological-anatomical investigations. Originally, 113 species were documented for this area and 31 species have been newly discovered since. Of these, 22 species have their type locality in the area under consideration. Eight species had to be excluded from the list due to incorrect identifications, wrongly attributed locality indications and synonymies (Peltonychia postumicola, P. gabria, P. insignis, Ischyropsalis pyrenaea, I. helvetica, Leiobunum tiscae, Nelima nigripalpe, Opilio ravennae). The majority of the new species were discovered in isolated areas of the Southern Alps, largely congruent with Massifs de Refuge, i.e. zones that where ice-free within glacial periods. Paranemastoma silli monticola Babalean, 2011 from Romania is upgraded to species rank, Paranemastoma monticola Babalean, 2011 stat. nov. Recently, molecular genetics (Ischyropsalis, Trogulus, Megabunus) and partly chemical and ecological methods (Megabunus, Nemastoma) helped to understand species delimitations more accurately, resulting in considerably higher number of species in the relevant genera than formerly believed. Due to recent man-made introductions eight species reached our area of investigation after 1978, but considerably more species in partial areas like Great Britain or the Netherlands. Successive range expansions of these species differ considerably from nearly zero to complete coverage of central Europe. Dasylobus graniferus is recorded for the first time in Germany. Following climate warming favourable conditions accelerate northward extension of native species, namely to the British Isles, northern parts of Central Europe and southern Scandinavia. By contrast, rainless dry summer periods influence the Central European opilionid fauna negatively causing regional extinctions.