Article · Wikipedia archive · Last revised Jun 25, 2026

Rilaena triangularis

Rilaena triangularis is a species of the harvestman family Phalangiidae. Previously it has been considered to be in the genus and subgenus Platybunus (Paraplatybunus) Dumitrescu, 1970, in the subfamily Platybuninae. Caution is needed with the name "Paraplatybunus". Although claimed as a potential genus in many online sources, the generic rank does not appear to have any foundation in the underlying academic literature, but instead was only published as a subgenus.

Last revised
Jun 25, 2026
Read time
≈ 2 min
Length
366 w
Citations
8
Source
Wikipedia ↗
Rilaena triangularis
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Opiliones
Family: Phalangiidae
Genus: Rilaena
Species:
R. triangularis
Binomial name
Rilaena triangularis
(Herbst, 1799)
Synonyms

Opilio triangularis
Platybunus triangularis
Platybunus (Paraplatybunus) triangularis

Rilaena triangularis is a species of the harvestman family Phalangiidae.1 Previously it has been considered to be in the genus and subgenus Platybunus (Paraplatybunus) Dumitrescu, 1970, in the subfamily Platybuninae. Caution is needed with the name "Paraplatybunus". Although claimed as a potential genus in many online sources, the generic rank does not appear to have any foundation in the underlying academic literature, but instead was only published as a subgenus.

Description

Rilaena triangularis is a harvestman with a broad natural distribution across Europe. This species was first described by Johann Friedrich Wilhelm Herbst in 1799, initially as Phalangium triangularis. It was later renamed through recombination in multiple forms but including Platybunus (Paraplatybunus) triangularis (Herbst, 1799) in Dumitrescu, 1970.2 The triangularis portion of its name (the species epithet) can be attributed to its "saddle pattern" on the upper (dorsal) surface, typically featuring a slightly darker triangular - or vase-shaped - "saddle" marking. That is often outlined with a lighter, whitish or pale-yellow colour.

Chemical defense

When disturbed, Rilaena triangularis emits a strong-smelling secretion as a chemical defense.1 This fluid contains 1,4-benzoquinone, 1,4-naphthoquinone and caprylic acid.

Range

Occurrences of Rilaena triangularis have been recorded and aggregated in GBIF across Europe, with the exception of Spain and Portugal. It has also been observed in north-west and north-east corners of the United States.31

Habitat

The species thrives in forests, floodplain forests and fens.145

References

References

  1. Raspotnig, G., Schaider, M., Föttinger, P., Leutgeb, V., & Komposch, C. (2015). Benzoquinones from scent glands of phalangiid harvestmen (Arachnida, Opiliones, Eupnoi): a lesson from Rilaena triangularis. Chemoecology, 25(2), 63–72. https://doi.org/10.1007/s00049-014-0177-y
  2. Adriano Brilhante Kury "Opilionological Record – a chronicle of harvestman taxonomy. Part 1: 1758–1804," The Journal of Arachnology, 38(3), 521-529, (1 December 2010)
  3. Rilaena triangularis Herbst, 1799 in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2020-06-14.
  4. Martens J. Spinnentiere, Arachnida. Weberknechte, Opiliones. Die Tierwelt Deutschlands, 64. Teil. Jena: Gustav Fischer Verlag; 1978. p. 449.
  5. Komposch C, Gruber J. Die Weberknechte Österreichs (Arachnida: Opiliones) Denisia. 2004;14:485–534.