Platybunus species are moderate-sized long-legged harvestmen of the household Phalangiidae, the central physique in bigger people being about eight millimetres lengthy (Martens 1978). Their most attribute characteristic is a comparatively massive eye-mound, distinctly wider than lengthy and occupying a big part of the anterior carapace. As with different European phalangiids, they eye-mound is ornamented with a row of denticles both sides although the physique lacks denticles over the rest of the dorsum. The physique is usually comparatively slender, tapering in direction of the rear (significantly in males), and is marked on the dorsum by a darker median band. The pedipalps have a pair of well-developed setose apophyses on the internal distal ends of the patella and tibia, and a sequence of lengthy spine-like tubercles on the underside of the femur. These tubercles presumably perform within the seize of prey, forming a basket that may be closed across the harvestman’s victims. Exterior sexual dimorphism in Platybunus is pretty minimal although females are total bigger and fatter. The penis is notably lengthy and slender with a comparatively small glans, offset from the shaft by a kind of marked constriction.
Martens (1978) recognises 4 species of Platybunus present in greater altitude areas of central Europe with the species P. bucephalus and P. pinetorum occupying a lot of the genus’ vary. Platybunus bucephalus could also be distinguished from P. pinetorum by, amongst different options, its comparatively shorter legs. Platybunus pallidus is endemic to the Carpathians, and the tiny P. alpinorelictus inhabits the Garda Mountains of northern Italy. One other species, P. anatolicus, was described from Turkey by Roewer (1956)*. On the whole, Platybunus species inhabit alpine and subalpine forests, being discovered among the many herbaceous undergrowth, underneath bark or on rock faces. The place their ranges overlap, P. bucephalus is extra accustomed to extending past the forest margins than P. pinetorum and could also be discovered above the tree-line. In recent times, the vary of P. pinetorum has prolonged northwards, being first recorded from the UK in 2010 and Sweden in 2015 (Fritzén et al. 2015). A minimum of some populations of P. pinetorum are able to reproducing parthenogenetically and this will have performed a component in its unfold.
*Platybunus mirus was described by Loman (1892) on the premise of two male specimens that supposedly got here from Sumatra. Although the id of this species has by no means been resolved (Loman’s illustration of the penis is a minimum of suggestive of a real Platybunus), the claimed locality appears nearly sure to be an error of some type.
The interior classification of the Phalangiidae stays in want of additional investigation. Platybunus has been recognised by some authors as forming a subfamily Platybuninae with a cluster of different western Palaearctic genera bearing comparable ventrally spined pedipalps (Zhang & Zhang 2012). Nonetheless, different authors haven’t separated this group from the subfamily Phalangiinae. The platybunines might characterize a phylogenetically coherent grouping, or their shared options might replicate variations to the same life model. The genital morphology of Platybunus is recognisably distinct from that of different platybunines which can argue towards any relationship (Martens 1978). Then again, platybunines would possibly presumably be distinguished from phalangiines by the chemical composition of their repugnatorial gland secretions (Raspotnig et al. 2015). A proper evaluation of the household’s evolution could be a welcome advance.
Fritzén, N. R., V. Rinne, M. Sunhede, A. Uddström, S. Van de Poel & P. De Smedt. 2015. Platybunus pinetorum (Arachnida, Opiliones) new to Sweden. Memoranda Soc. Fauna Flora Fennica 91: 37–40.
Loman, J. C. C. 1892. Opilioniden von Sumatra, Java und Flores. In: M. Weber (ed.) Zoologische Ergebnisse einer Reise in Niederländisch Ost-Indien vol. 3 pp. 1–26, pl. 1. E. J. Brill: Leiden.
Martens, J. 1978. Spinnentiere, Arachnida: Weberknechte, Opiliones. Gustav Fischer Verlag: Jena.
Raspotnig, G., M. Schaider, P. Föttinger, V. Leutgeb & C. Komposch. 2015. Benzoquinones from scent glands of phalangiid harvestmen (Arachnida, Opiliones, Eupnoi): a lesson from Rilaena triangularis. Chemoecology 25: 63–72.
Roewer, C. F. 1956. Über Phalangiinae (Phalangiidae, Opiliones Palpatores). (Weitere Weberknechte XIX). Senckenbergiana Biologica 37 (3–4): 247–318.
Zhang, C., & F. Zhang. 2012. On the subfamilial project of Platybunoides (Opiliones: Eupnoi: Phalangiidae), with the outline of a brand new species from China. Zootaxa 3190: 47–55.