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...

Disjunction in Arachnospila (Pompilidae: Hymenoptera)Convergent evolution or recent dispersal?

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Disjunction in Arachnospila (Pompilidae: Hymenoptera)Convergent evolution or recent dispersal?

Abstract

Convergent evolution is defined as unrelated species evolving similar traits. A disjunct distribution is the appearance of species or groups of species in disconnected geographical areas. Is the disjunction we see in Arachnospila due to a recent disjunct distribution/long distance dispersal event or long-term convergent evolution? 

https://digitalcommons.usu.edu/researchweek/ResearchWeek2025/all2025/218/