Opiliones in Belgium


(updated xii.2023)

Introduction

While the Belgian community of eight-legged animals shudders with fear in view of the next excursion of the flourishing Arabel (Arachnologia Belgica), one little group keeps his peace of mind: the Harvestmen. The majority of arachnologists has lost interest since some simple youth experiments with the legs. I couldn't beat the knowledge of the Arabel-people, so I took the Opiliones as my territory.

Dr. Baert (Royal Belgian Institute of Natural Sciences) kindly put the relevant collections at my disposal. Although Opiliones were never the object of a dedicated sampling session, the bottles were rich enough to keep me happy for several years on row. I added some material from my own entomological studies during the 1980s and from the former Laboratory of Oecology of the State University of Ghent. Another important source of information, mainly about the western part of the country, were the data obtained by W. Slosse with his pitfall campaigns during 1994-'96. Maps based on all this observations were drawn and made available on the internet in June 1999.

A new set of maps was drawn in 2004. The samples of several more pitfall campaigns were included. I walked through the old dataset, checked suspicious observations and made corrections if necessary.

The third set of maps was published on paper in 2010. A digital version is available through a link on this page.

More recently some new species (Nemastoma dentigerum, Nelima doriae) were found in Belgium and Trogulus nepaeformis s.l. is now known to be two species: T. closanicus and T. nepaeformis.

Though Gyas titanus is mentioned in an article from 1933 (see below), we don't think the species is still present in Belgium; if it ever has been.

Checklist for Belgium (updated xii.2023)

Species count is now 32 (+1, †)
This is just the list. See the PDFs below for older maps and discussion

Trogulidae

Trogulus tricarinatus (Linnaeus, 1767)
Trogulus closanicus Avram, 1971
Trogulus nepaeformis (Scopoli, 1763)
Anelasmocephalus cambridgei (Westwood, 1874)

Nemastomatidae

Nemastoma bimaculatum (Fabricius, 1775)
Nemastoma dentigerum Canestrini, 1873
Nemastoma lugubre (Müller, 1776)
Nemastoma triste (C.L. Koch, 1835)
Paranemastoma quadripunctatum (Perty, 1833)
Mitostoma chrysomelas (Hermann, 1804)

Gagrellidae

Nelima doriae (Canestrini, 1871)

Phalangiidae

Phalangium opilio Linnaeus, 1758
Opilio parietinus (De Geer, 1778)
Opilio saxatilis C.L. Koch, 1839
Opilio canestrinii (Thorell, 1876)
Platybunus pinetorum (C.L. Koch, 1839)
Rilaena triangularis (Herbst, 1799)
Astrobunus laevipes (Canestrini, 1872)
Lophopilio palpinalis (Herbst, 1799)
Oligolophus tridens (C.L. Koch, 1836)
Oligolophus hanseni (Kraepelin, 1896)
Paroligolophus agrestis (Meade, 1855)
Lacinius horridus (Panzer, 1794)
Lacinius ephippiatus (C.L. Koch, 1835)
Odiellus spinosus (Bosc d'Antic, 1792)
Mitopus morio (Fabricius, 1799)
Gyas titanus Simon, 1879 (†)
Dicranopalpus ramosus (Simon, 1909)
Amilenus aurantiacus (Simon, 1881)
Homalenotus quadridentatus (Cuvier, 1795)
Leiobunum rotundum (Latreille, 1798)
Leiobunum blackwalli Meade, 1861
Leiobunum sp A

 Reported in Louis Fage (1933) as collected by Robert Leruth in the Grotte carrière du Petit Lanaye.
A follow up article by Robert Leruth (1935) gives again some opiliones found in caves, but G. titanus is not in this list.
Also, though we have samples (1993-'94, and 2004-'05) from in and around the same caves, we could not confirm the presence of G. titanus in Belgium.

See:
• Louis Fage —1933— Les Arachnides cavernicoles de Belgique.
Bulletin de la Société entomologique de France. Vol 38 pp 53-56.
• Robert Leruth —1935— Exploration biologique des cavernes de la Belgique et du Limbourg Hollandais. XXVIIe Contribution : Arachnida. Bulletin du Musée royal d'Histoire naturelle de Belgique. Tome XI, n°39, pp 1-34.

Some references

Hooiwagens in België — een overzicht
(= Opiliones in Belgium — an overview)
Nieuwsbr. Belg. Arachnol. Ver. (2010), 25(2): 138-157. Download PDF file (1MB)

De hooiwagen Nelima doriae (Canestrini, 1871) bevestigd voor België
(= Presence of Nelima doriae in Belgium is confirmed)
Nieuwsbr. Belg. Arachnol. Ver. (2011), 27(1): 40-41. Download PDF file (0.5MB)

Nemastoma dentigerum (Arachnida, Opiliones) found in Belgium
Nieuwsbr. Belg. Arachnol. Ver. (2015), 30(1): 4-7. Download PDF file (0.7MB)

The situation of the Genus Trogulus (Arachnida - Opiliones - Trogulidae) in Belgium
Nieuwsbr. Belg. Arachnol. Ver. (2017), 32(3): 112-120. Download PDF file (5.5MB)

First record of the harvestman Astrobunus laevipes (Canestrini, 1872) in Belgium
(Opiliones: Phalangiidae)

Journal of the Belgian Arachnological Society (2022), 37(2): 99-103. Download PDF file (1MB)

Links (latest check 03.xii.2023)

Les araignées de Belgique et de France An impressive collection of pictures of many species. Shows also many details helping with a correct identification.
www.belgianspiders.be The website of Arachnologia Belgica (Arabel)

Path: Opiliones in Belgium