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The Dysderidae fauna of the Maltese Islands is reviewed. Dysdera kollari Doblika, 1853, D. lagrecai Alicata, 1964 and Harpactea sicula Alicata, 1966 are recorded for the first time from the Maltese archipelago, and the latter two species are recorded for the first time outside Italian territories. Harpactea corticalis (Simon, 1882) is removed from the Maltese dysderid fauna list. Distributional notes for all four species present in the Maltese Islands are provided, with the first records of Dysderidae from Comino.
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Arachnologische Mitteilungen / Arachnology Letters 62: 82-85 Karlsruhe, September 2021
e Maltese archipelago consists of a number of small, low
islands and islets located in the centre of the Mediterranean
Sea, aligned in a North-West to South-East direction. e to-
tal area of the archipelago amounts to 314 km2, and it lies ap-
proximately 96 km to the south of the Italian island of Sicily,
and some 350 km directly north of the Libyan coast of North
Africa. e climate is typically Mediterranean, with hot, dry
summers and mild, wet winters. Notwithstanding their small
size, an estimated 4500 species of terrestrial and freshwater
arthropods inhabit the Maltese Islands (Dandria & Mifsud
2017). Currently, the known spider fauna of the Maltese Is-
lands consists of 145 species from 31 families (Dandria et al.
2005, 2012, Dentici 2018).
e location of the Mediterranean as a meeting point of
Europe, the Levant and Africa, together with its varied clima-
tic regimes and complex physical geography, have endowed it
with high levels of species diversity and endemism. is di-
versity is also exhibited by the family Dysderidae, which is re-
presented by just over 400 species in the Mediterranean regi-
on, distributed in twenty-two genera (World Spider Catalog
2021). Dysderids are six-eyed haplogyne spiders with stout,
relatively hairless legs and large chelicerae. eir tendency to
inhabit damp areas, and the common belief that their large
chelicerae are adapted for hunting terrestrial isopods, have
led to the vernacular name “woodlouse spiders”, despite the
fact that dysderids will prey on a wide variety of invertebrates
(Pollard et al. 1995).
Despite the diversity of species of Dysderidae in the Me-
diterranean region, the dysderid species inhabiting the Mal-
tese Islands never attracted much attention, and so far only
two species have been recorded as part of broader works rela-
ted to the Maltese aranaeofauna: Dysdera crocata C. L. Koch,
1838 and Harpactea corticalis (Simon, 1882). e present work
records an additional three species, and notes on all four spe-
cies are provided (Fig. 1).
Material and methods
Dysderid spiders were collected from Malta, Comino and
Gozo throughout the years 2019 to 2021 by searching under
stones during the wet season. Some material was obtained
from a mesovoid shallow substratum (MSS) trap (López
& Oromi 2010) aimed at collecting endogean coleopterans
(only the date of emptying the traps is known). All material
was stored in 75% ethanol for identication and deposited at
the Crop Research Institute in Prague, Czech Republic. A
distributional map was constructed on the basis of the col-
lected material, as well as records in the literature. Nomencla-
ture follows the World Spider Catalog (2021).
Results
Dysdera Latreille, 1804
Dysdera crocata C. L. Koch, 1838 (Figs 2a, 3a, 4a)
Material examined. MALTA. Malta: Lapsi, Siġġiewi,
35.82969°N, 14.42050°E, 30 m a.s.l, MSS trap, 3. Jun. 2019,
leg. J. Borg, 1 ); Rdum tal-Madonna, Mellieħa, 35.98936°N,
14.37455°E, 29 m a.s.l., 27. Oct. 2019, leg. T. Cassar, 1 juve-
nile; Misraħ Għar il-Kbir, Siġġiewi, 35.85241°N, 14.39691°E,
223 m.a.s.l., 12. Jan. 2020, leg. T. Cassar, 3 )); same location
as previous, 2. Feb. 2020, leg. T. Cassar, 2)); Buskett, lim-
its of Siġġiewi, 27. Feb. 2021, leg. T. Cassar, 1(. Comino:
The Dysderidae of the Maltese Islands (Arachnida: Araneae)
Thomas Cassar & Milan Řezáč
doi: 10.30963/aramit6209
Abstract. The Dysderidae fauna of the Maltese Islands is reviewed. Dysdera kollari Doblika, 1853, D. lagrecai Alicata, 1964 and Harpactea
sicula Alicata, 1966 are recorded for the rst time from the Maltese archipelago, and the latter two species are recorded for the rst time
outside Italian territories. Harpactea corticalis (Simon, 1882) is removed from the Maltese dysderid fauna list. Distributional notes for all
four species present in the Maltese Islands are provided, with the rst records of Dysderidae from Comino.
Key words: Comino, Dysdera, Gozo, Harpactea, Malta, Mediterranean, new records, spiders
Zusammenfassung. Die Dysderidae der Maltesischen Inseln (Arachnida: Araneae). Die Dysderiden-Fauna der maltesischen Inseln
wird besprochen. Dysdera kollari Doblika, 1853, D. lagrecai Alicata, 1964 und Harpactea sicula Alicata, 1966 werden zum ersten Mal für
den maltesischen Archipel nachgewiesen – die beiden letztgenannten Arten zum ersten Mal außerhalb Italiens. Harpactea corticalis
(Simon, 1882) wird von der Liste der maltesischen Dysderidae gestrichen. Die Verbreitung der vier Dysderiden-Arten der maltesischen
Inseln wird erläutert und die ersten Nachweise von Dysderidae von der Insel Comino erbracht.
Thomas CASSAR, Department of Biology, Faculty of Science, University of Malta,
Msida MSD 2080; E-mail: thomas.cassar@um.edu.mt;
ORCiD: https://orcid.org/0000-0001-8703-813X
Milan ŘEZÁČ, Crop Research Institute, Drnovská 507, Ruzyně, 161 06 Praha 6, Czech
Republic; E-mail: rezac@vurv.cz; ORCiD: https://orcid.org/0000-0003-4373-7064
Academic Editor: Theo Blick
submitted 7.6.2021, accepted 27.9.2021, online 30.9.2021
Fig. 1: Map showing the locations from which dierent species of Dysderi-
dae have been recorded earlier or collected in the present study from the
Maltese Islands
Dysderidae of the Maltese Islands 83
36.01161°N, 14.33663°E, 25 m a.s.l., 6. Feb. 2021, leg. T. Cas-
sar, 1 (. Gozo: Rabat, 36.04037°N, 14.24430°E, 6. Feb. 2020,
leg. B. Grech, 1 juvenile.
Distribution. Europe, Turkey, Caucasus, Iraq and Central
Asia (native); North America, Chile, Brazil, South Africa,
Australia, New Zealand and Hawaii (introduced) (World
Spider Catalog 2021).
Remarks. Baldacchino et al. (1993) recorded this spe-
cies from Sliema and the Tas-Salib area of Rabat (Malta).
Kritscher (1996: sub D. crocota) recorded it from Mdina, Flo-
riana, Golden Bay, St. Julian’s and the Kalkara Ravine-Mistra
Bay area in Malta; as well as from Marsalforn and Wied tal-
Qliegħa (Żebbuġ) in Gozo. Dysdera crocata certainly appears
to be the most common and widespread dysderid species in
the Maltese Islands, and has been collected among others
from garrigue, disturbed land, building ruins, agricultural land
and valleys among others.
Dysdera kollari Doblika, 1853 (Figs 2b, 4b)
Material examined. MALTA. Malta: Fiddien Valley, Rabat,
35.88852°N, 14.38066°E, 130 m a.s.l., 22. Dec. 2019, leg.
T.Cassar, 1 (.
Distribution. Italy, the Balkans, Greece and Turkey (World
Spider Catalog 2021).
Remarks. New record for the Maltese Islands (also recorded
at one site on Malta by Rehfeldt, in litt.). e single specimen
collected may indicate that this is a rare species in the Maltese
archipelago. e specimen was collected from under a large
rock in mud in very close proximity to a natural freshwater
stream which forms during the wet season.
Dysdera lagrecai Alicata, 1964 (Figs 2c, 3b, 4c)
Material examined. MALTA. Gozo: Ta’ Ċenċ, Sannat,
36.02125°N, 14.25813°E, 127 m a.s.l., 29. Dec. 2019, leg.
T.Cassar, 1 ), 1 (.
Distribution. Sicily & Aegadian Islands (Italy) (Alicata
1973).
Remarks. New record for the Maltese Islands. Alicata (1964)
described this species on the basis of specimens collected from
various locations in Sicily; namely the Madonie, the Nebrodi,
Mount Etna, the Hyblaean Mountains and the Provinces of
Catania, Syracuse, Agrigento, Caltanissetta and Enna. us,
the male and female specimens collected in Gozo become the
rst records of D. lagrecai outside of the island of Sicily and
the nearby Aegadian Islands. Alicata (1964) also stated that
the species is euryoecious, found both in lowlands and at high
altitudes. e Gozitan specimens were collected under a stone
in garrigue on a cli plateau.
Harpactea Bristowe, 1939
Harpactea corticalis (Simon, 1882)
Material examined. None.
Distribution. France, Italy (World Spider Catalog 2021).
Fig. 3: Palpal bulbs from three sampled dysderid species in the Maltese
Islands, ventral view. a. Dysdera crocata; b. D. lagrecai; c. Harpactea sicula;
scale bars 0.50 mm (a), 0.25 mm (b-c)
Fig. 2: Dysderidae collected from the Maltese Islands, habitus, dorsal view. a. Dysdera crocata, male; b. D. kollari, female; c. D. lagrecai, male; d. Harpactea
sicula, male; scale bars 2.5 mm (a-c), 1.5 mm (d)
84 T. Cassar & M. Řezáč
Remarks. Kritscher (1996) recorded H. corticalis from the
Maltese Islands on the basis of a single male specimen col-
lect ed from Wied tal-Qliegħa (Żebbuġ) in Gozo. Despite
similarities to other species in the corticalis group, namely
H.major and H. sicula, it is possible to distinguish H. cortica-
lis from other related species if a male specimen is available
due to the strong curvature of the palpal bulb’s apical proces-
ses (Alicata 1966). e identication of Kritscher’s Gozitan
specimen was justied by the fact that (i) the specimen was
a male, and therefore the important distinguishing charac-
ters of the palpal bulb could be examined, and (ii) Kritscher
(1996) states that he directly compared his Gozitan specimen
with the original type material of H. corticalis deposited in the
French National Museum of Natural History.
However, the possibility that Kritscher’s record is a misi-
dentication of H. sicula cannot be excluded. In fact, Bosmans
et al. (2017) argued that many records of H. corticalis in the
Mediterranean are misidentications, attributed to the relati-
ve simplicity and similarity of palpal bulbs across the corticalis
group (Bosselaers & Van Keer 2016). Moreover, H. corticalis
has not been collected in the Maltese Islands since Kritscher
(1996) recorded it from Gozo for the rst time. e present
study also revealed that H. sicula is widespread in the Maltese
archipelago, a species which may be easily misidentied as
H. corticalis. We therefore propose that H. corticalis should be
removed from the Maltese dysderid fauna until further inves-
tigation can conrm its presence beyond doubt.
Harpactea sicula Alicata, 1966 (Figs 2d, 3c, 4d)
Material examined. MALTA. Malta: Lapsi, Siġġiewi,
35.82969°N, 14.42050°E, 30 m a.s.l., MSS trap, 3. Jun. 2019,
leg. J. Borg, 2 ((; Dingli Clis, 35.84919°N, 14.39033°E,
239m a.s.l., 8. Feb. 2020, leg. T. Cassar, 1 ). Comino: Blue
Lagoon, 36.01363°N, 14.32458°E, 15 m a.s.l., 23. Feb. 2020,
leg. T. Cassar, 1 (. Gozo: Rabat, 36.04037°N, 14.24430°E, 6.
Feb. 2020, leg. B. Grech, 1 (; same location and collector, 14.
Feb. 2020, 1 ).
Distribution. Sicily, Aegadian Islands & Ustica (Italy) (Ali-
cata 1973).
Remarks. is species was described by Alicata (1966) on
the basis of material collected across various locations on the
island of Sicily. e above material thus become the rst re-
cords of H. sicula outside of Sicily and its aliated islands
(also recorded on Malta at three sites by Rehfeldt, in litt.).
When considering the corticalis group, Alicata (1966: p. 205)
wrote the following [in Italian]: “I have considered these
three species as distinct from each other but, being allo patric,
they could also be subspecies of a single species; however, the
reproductive isolation of the populations in question can only
be proven through breeding; I prefer to indicate them as spe-
cies for the clear dierences between them.” If the identi-
cation of H. corticalis from Gozo by Kritscher (1996) were
to be proved correct, H. sicula and H. corticalis would no lon-
ger be considered allopatric, as both species would have been
recorded from the relatively small island of Gozo, although
not from precisely the same location. However, as mentioned
above, the record of H. corticalis from Gozo was most likely a
misidentication of H. sicula, so for now it seems that H.cor-
ticalis and H. sicula remain allopatric.
Acknowledgements
We are grateful to Mr James Borg for providing specimens captured
in his MSS traps, and to Mr Benjamin Grech for providing specimens
he collected from the island of Gozo.
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Fig. 4: Epigynal regions of four
sampled dysderid species from
the Maltese Islands. a. Dysdera
crocata; b. D. kollari; c. D. lagre-
cai; d. Harpactea sicula; scale
bars 0.74 mm (a), 0.50 mm (b-
c), 0.25 mm (d)
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... Nevertheless, two spider species previously only known from North Africa (Acarauchius insigniceps and Zelotes poecilochroaeformis) were recorded for the first time from Europe; possible reasons, as discussed already, may be natural dispersion through air currents or direct, accidental introduction through human activity. Many other species are shared with Sicily, and indeed species which were previously considered Italian endemics are now known to occur in the Maltese Islands, namely Harpactea sicula Alicata, 1966(Cassar & Řezáč 2021 and Nelima meridionalis Marcellino, 1972 (present work). ...
... As a result of the contribution of the present work, the known spider fauna of the Maltese Islands increases from 150 species (Pfliegler et al. 2017, Dentici 2018, Cassar & Řezáč 2021, Cassar et al. 2022 to 186 species. The number of species of harvestmen has also increased from five to six species. ...
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Le Dysdera del gruppo andreinii della fauna italiana (Araneae, Dysderidae)
  • P Alicata