Leiobunum sp.

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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 sp. to the National Museum of Natural History.

Status and distribution in Luxembourg

Records of Leiobunum blackwalli in Luxembourg. Data source: Recorder-Lux, iNaturalist & GBIF, 2020-02-27.

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 overseas, probably reaching the Netherlands first. It is still unknown exactly where it came from. 1

The species was first documented in 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 the day. This behaviour is even more 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 great damage. 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).


Records of Leiobunum religiosum in Luxembourg. Data source: Recorder-Lux, iNaturalist & GBIF, 2020-02-27.

  • 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]

 Page content last updated on 2019-12-10. Last proofread by Caroline Grounds on 2019-12-10.