Improphantes improbulus (Simon, 1929)
Description
Male palp with tapering lamella in distal third, pointed distally. Epigyne with strongly developed epigynal plates, enclosing scapus collar-like, therefore also visible from ventral, posterior part of scapus almost 4 times as wide as long. Prosoma yellow-brown, with or without dorsal spot. Legs clay-yellow. Opisthosoma grey-white to black.
Body length male: 2-2.3 mmBody length female: 2.1-2.7 mm
Additional information
in litter layer and small caves
Troglophile species (Mammola et al., 2022)
Character states from linyphiid key
Distribution
Phenology
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
 |  |
Figures
Pedipalp, ventral view
(Miller & Svatoň 1978)
Pedipalp, ventral view
(Heimer & Nentwig 1991)
Pedipalp, retrolateral view
(Thaler 1986c)
Pedipalp, prolateral view
(Thaler 1986c)
Paracymbium
(Thaler 1986c)
Epigyne
(Heimer 1978)
Epigyne
(Heimer & Nentwig 1991)
Epigyne
(Miller & Svatoň 1978)
Epigyne, lateral view
(Miller & Svatoň 1978)
Epigyne, antero-ventral view
(Thaler 1986c)
Epigyne/vulva, aboral view
(Thaler 1986c)
Epigyne, ventral view
(Thaler 1986c)
Vulva
(Miller & Svatoň 1978)
Distribution List
References
Blagoev G, Deltshev C, Lazarov S, Naumova M (2018) The spiders (Araneae) of Bulgaria. Version: August 2018. National Museum of Natural History, Bulgarian Academy of Sciences. Online at http://www.nmnhs.com/spiders-bulgaria/ (accessed on 10.9.2018) 
Blick T, Finch O-D, Harms K H, Kiechle J, Kielhorn K-H , Kreuels M, Malten A, Martin D, Muster C, Nährig D, Platen R, Rödel I, Scheidler M, Staudt A, Stumpf H, Tolke D (2016) Rote Liste und Gesamtartenliste der Spinnen (Arachnida: Araneae) Deutschlands. 3. Fassung, Stand April 2008, einzelne Änderungen und Nachträge bis August 2015. Naturschutz und Biologische Vielfalt 70/4: 383-510
Branco V V, Morano E, Cardoso P (2019) An update to the Iberian spider checklist (Araneae). Zootaxa 4614: 201-254
Deltshev C, Vrenozi B, Blagoev G, Lazarov S (2011b) Spiders of Albania – faunistic and zoogeographical review (Arachnida: Araneae). Acta Zoologica Bulgarica 63: 125-144
Esyunin S L, Efimik V E (1996a) Catalogue of the spiders (Arachnida, Aranei) of the Urals. KMK Scientific Press, Moscow, 228 pp.
Gajdoš P, Svatoň J, Sloboda J (1999) Katalóg pavúkov Slovenska. Catalogue of Slovakian spiders. Ústav kr. ekol. SAV, Bratislava, 337 pp.
Heimer S (1978) Zur intragenerischen Isolation der Arten der Gattung Pocadicnemis Simon 1884. Zoologische Abhandlungen, Staatliches Museum für Tierkunde Dresden 35: 101-112
Heimer S, Nentwig W (1991) Spinnen Mitteleuropas. Paul Parey Berlin
Isaia M, Tolve M, Pantini P (2025) Araneae.it: 2.0: the new updated version of the digital catalog of the Italian spiders and other arachnids (Arachnida: Araneae, Opiliones, Scorpiones, Pseudoscorpiones, Palpigradi, Solifugae). Fragmenta Entomologica 57: 197-204
Komnenov M (2017) New data on spider fauna (Araneae) of Shar Mountain, north-western Macedonia. Proceedings of the 5th Congress of the Ecologists of Macedonia, with international participation (Ohrid, 19th-22nd October 2016). Special issues of the Macedonian Ecological Society 13: 44-61
Kreuels M, Staudt A, Christian S (2019) Die Spinnenfauna von Luxemburg – eine Zusammenstellung der Nachweise aus den Jahren 1906-2018 (Arachnida: Araneae). Bulletin de la Société des naturalistes luxembourgeois 121: 203-230
Le Peru B (2007) Catalogue et répartition des araignées de France. Revue Arachnologique 16: 1-468
Mammola S, Pavlek M, Huber B A, Isaia M, Ballarin F, Tolve M, Čupić I, Hesselberg T, Lunghi E, Mouron S, Graco-Roza C, Cardoso P (2022) A trait database and updated checklist for European subterranean spiders. Scientific Data 9(236): 1-13
Miller F, Svatoň J (1978) Einige seltene und bisher unbekannte Spinnenarten aus der Slowakei. Annotationes Zoologicae et Botanicae Bratislava 126: 1-19
Nae A (2010) Improphantes improbulus (Simon, 1929) (Araneae, Linyphiidae) new record for the Roumanian fauna. Travaux de l’Institut de Spéologie “Émile Racovitza” 49: 81-85
Otto S (2022) Caucasian spiders. A faunistic database on the spiders of the Caucasus Ecoregion. Database version 02.2022. Internet: caucasus-spiders.info.
Ponomarev A V (2022) Spiders (Arachnida: Araneae) of the southeast of the Russian Plain: catalogue, the fauna specific features. SSC RAS Publishers, Rostov-on-Don, 640 pp.
Růžička V (1996) Pavouci kamenitých sutí a pseudokrasových jeskyní Národního parku Podyjí [Spiders of stony debris and pseudokarst caves in Podyji National Park]. Příroda Sborník prací z ochrany přírody, Praha 3: 123-132
Růžička V, Řezáč M (2022a) Seznam pavouků České republiky. List of spiders of the Czech Republic. Online at https://www.arachnology.cz/seznam-pavouku-cr-26.html and https://www.arachnology.cz/en/seznam-pavouku-cr-26.html
Staudt A, Weber D, Nährig D (2013) Webspinnen (Arachnida, Araneae) aus Höhlen des Großherzogtums Luxemburg. Ferrantia 69: 115-157
Thaler K (1986c) Vier bemerkenswerte Leptyphantes-Arten aus dem Mittelmeergebiet und aus Vorderasien (Arachnida: Aranei, Linyphiidae). Sitzungsberichte der Österreichischen Akademie der Wissenschaften (I) 194: 311-325
WSC (2026) World Spider Catalog. Version 27. Natural History Museum Bern, online at http://wsc.nmbe.ch (13.2.2026) doi: 10.24436/2