Leiobunum spp.

English Daddy long legs ISEIA: C2
Lëtzebuergesch Schneider EASIN
Français Leiobunum, faucheux Wikipedia: Wikipedia - English - Leiobunum Wikipedia - Français - Wikipedia - Deutsch - Namenloser Rückenkanker Nederlands
Deutsch Namenloser Rückenkanker  Wikispecies: n/a
Nederlands n/a Back to the list of invertebrates

Report the species

Report Leiobunum to the National Museum of Natural History.

Importance and distribution in Luxembourg

Distribution map of Leiobunum blackwalli in Luxembourg. Recorder-LUX & iNaturalist, 2019.08.21.

Since probably 2000, a completely unknown harvestman started its quick expansion through Central Europe. The species could be classified in the genus Leiobunum, but is different from other European species. It is assumed that it arrived with ships from oversea, probably reaching the Netherlands first. It is still unknown where exactly it came from. 1

The species was first documented for Luxembourg in 2009 (M. Meyer & C. Muster). Big clusters of the species (100-200 animals) have been observed in Rodange and Esch-sur-Alzette in the south of the country. The other findings were individuals or small groups of at most 10 animals. The species is common in the Gutland area while largely missing in the Oesling (Muster & Meyer 2014).

Leiobunum species generally tend to cluster together during daytimes. This behaviour is even stronger pronounced in the species in question. Mass aggregations of several hundreds of individuals have been observed.

Many observations show that in spite of its high reproduction rate this “new” Leiobunum species seems to coexist well with indigenous species and integrates in the native fauna without greater damages. But surely great colonies of the species compete for food with other similar predators.

Risk assessment

ISEIA protocol: C2 (2+2+2+1) (Ries et al. 2017: 68).

Bibliography concerning Luxembourg

Distribution map of Leiobunum religiosum in Luxembourg. Recorder-LUX & iNaturalist, 2019.08.21.

  • Muster, C. & M. Meyer, 2014. Verbreitungsatlas der Weberknechte des Großherzogtums Luxemburg, Ferrantia 70. Musée national d’histoire naturelle, Luxembourg, 112 S. (PDF 3.8 MB)
  • Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]

Suggested citation of this webpage

Ries, C. & M. Pfeiffenschneider (Eds.), 2019. Leiobunum spp. In: neobiota.lu - Invasive Alien Species in Luxembourg. URL: https://neobiota.lu/leiobunum-sp/ [21.08.2019].

 Last updated on Friday, April 20, 2018.


  1. Cf. Wijnhoven H, AL Schönhofer & J Martens (2007) An unidentified harvestman Leiobunum sp. alarmingly invading Europe (Arachnida: Opiliones). Arachnol. Mitt. 34: 27-38. (https://www.natur-in-nrw.de/Download/Martens_Leiobunum_2007.pdf)