Hidden in the wrack: spider (Arachnida, Araneae) diversity and new records for Italy from Posidonia banquettes

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  Hidden in the wrack: spider (Arachnida, Araneae) diversity and new records for Italy from Posidonia banquettes ABSTRACT Posidonia oceanica (L.) Delile beach wrack deposits (banquettes) are a characteristic coastal habitat of the Mediterranean Sea, yet their invertebrate communities remain poorly studied. Here we report the results of a survey from January to November 2024 of the spider fauna (Order Araneae) associated with Posidonia banquettes at Sant’Agostino beach (Civitavecchia, Latium, central Italy), using four complementary sampling methods (surface and underground pitfall traps, Berlese-Tullgren funnel extraction, and visual census). A total of 161 specimens were collected, with 17 species assigned to 11 families among adult individuals. The dominant families were Argyronetidae (39.4%), represented exclusively by Chaerea maritimus Simon, 1885, and Gnaphosidae (33.8%). Three species are recorded for the first time in Italy: Dysdera gamarrae Ferrández 1984, Gnaphosa jucu...

Arachnological biosecurity on one of the world’s most remote inhabited islands: a checklist of stowaway spiders found on Saint Helena, South Atlantic Ocean

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Arachnological biosecurity on one of the world’s most remote inhabited islands: a checklist of stowaway spiders found on Saint Helena, South Atlantic Ocean

Abstract
An annotated checklist of non-native spiders intercepted by biosecurity staff of the Agriculture & Natural Resources Division (ANRD) of the Saint Helena Government is presented, along with a complete list of all other known stowaway specimens examined by us in other collections. As a consequence, Araneus quadratus Clerck, 1757 and Neoscona rapta (Thorell, 1899) and four generic-level taxa are newly recorded for the list of Saint Helenian spiders. Five morphospecies, including one that constituted a new genus record, are newly reported (Clubiona sp., Crossopriza sp., Palystes sp., Physocyclus sp., and Zenodorus sp.). Palystes sp. also represents the first record of the family Sparassidae Bertkau, 1872 for Saint Helena. One further record of a previously known species, Steatoda nobilis (Thorell, 1875), is made from a specimen recently intercepted in an inbound parcel in 2024. Finally, a list of additional immature specimens, unidentifiable below the family level but nonetheless examined for this work, are presented to complete the catalogue of specimens in the ANRD collections. The total number of spider families recognised on the island raises to 33 and valid genera and species (i.e. excluding undetermined morphospecies) to 92 and 116, respectively.

As always, a special thanks to Danni Sherwood for providing me with this manuscript via ResearchGate

Sherwood, Danniella & Fowler, Liza. (2025). Arachnological biosecurity on one of the world’s most remote inhabited islands: a checklist of stowaway spiders found on Saint Helena, South Atlantic Ocean. Natura Somogyiensis. 45. 57-68. 10.24394/NatSom.2025.45.57.