A new species of Brachychthoniidae (Acari: Oribatida) from the Eastern Central Alps (Austria, Tyrol), with the proposal of a new genus

Heinrich Schatz

doi:10.24349/acarologia/20214436

Abstract

A new species of the family Brachychthoniidae (Acari: Oribatida), Arcochthonius roynortoni n. sp., found on the summit of the Festkogel mountain (3030 m a.s.l.) in the Central Alps (Obergurgl, Tyrol, Austria), is described and illustrated, based on adults. Arcochthonius n. gen. is proposed for this species. The relationships to the closely related genus Synchthonius Hammen, 1952 and other genera of Brachychthoniidae are discussed. The new species is unique among Brachychthoniidae in having arched ridge-like sculpturing on thickened anterior edges of medial and posterior notogastral sclerites, and differs by a combination of morphological character states. Some notes on ecology and biology are given.

Highlights

Prior to the present study 174 species of the oribatid family Brachychthoniidae Thor, 1934 were described and grouped into 11 genera using morphological characters of the adult
About two third of all species are recorded from the Holarctic region (Subías 2004, electronic update 2020), with 39 species known from Austria (Krisper et al 2017)
Brachychthoniidae are among the smallest oribatid mites, the length of most adults varies between 120-250 μm

Summary

Introduction

Prior to the present study 174 species of the oribatid family Brachychthoniidae Thor, 1934 (including 12 spp. inquir., Schatz et al 2011, updated) were described and grouped into 11 genera using morphological characters of the adult. About two third of all species are recorded from the Holarctic region (Subías 2004, electronic update 2020), with 39 species known from Austria (Krisper et al 2017) They are common inhabitants of forest litter and moss, but occur in xeric grassland or in tundra with lichens, as well as in raw humus and soil, and in some localities, they were found with considerable abundances (Schweizer 1956, Moritz 1976a, b, Leonov 2020). The late Konrad Thaler, Innsbruck, forwarded me collections of oribatid mites from high mountains of the Eastern Alps, in particular from the summit of the Festkogel mountain. This material contains numerous remarkable findings which will be discussed elsewhere (Schatz in prep.).

Material and methods

C E weak separated

Findings

Notes on ecology and biology