A comparison of adhesive performance among six cursorial spider species

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  A comparison of adhesive performance among six cursorial spider species Abstract The ability to adhere to surfaces is particularly relevant for cursorial predatory arthropods like hunting spiders, which often traverse relatively complex environments characterized by large variation in substrate properties. Here, we evaluated the adhesive performance of six hunting spider species that are common in eastern temperate North America and lack specialized tarsi for climbing smooth or inclined surfaces [Lycosidae: Pardosa lapidicina Emerton, 1885 and Rabidosa rabida (Walckenaer, 1837); Oxyopidae: Oxyopes salticus Hentz, 1845; Pisauridae: Pisaurina mira (Walckenaer, 1837); Dolomedidae: Dolomedes triton (Walckenaer, 1837), and Dolomedes scriptus Hentz, 1845]. We tested adhesion performance as shear load resistance (g) on a glass plate, and as the angle of failure (°) when the plate was gradually inclined relative to horizontal. Average angle of failure and shear resistance differed among ...

Behavioural variation in the invasive cellar spider Pholcus manueli (Araneae: Pholcidae)

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Behavioural variation in the invasive cellar spider Pholcus manueli (Araneae: Pholcidae)

Abstract

Behaviours such as boldness and exploration are highly plastic and as such, we expect differences between populations, especially for invasive species. In particular, populations at the leading edge of an invasion front may display differences in these behaviours relative to long established core populations as they are often key to their dispersal and invasion success. Likewise, in species with sexual dimorphism, the importance of these behaviours to invasion success may differ for males and females. Here we report on an invasive cellar spider, Pholcus manueli (Araneae: Pholcidae), that is expanding westward across the United States. We investigated whether boldness in response to simulated predator cues (physical and airborne disturbances) and exploration of a novel environment varied across P. manueli’s invasive range and between males and females. We found significant differences in the reaction to the simulated predator cues, but not in exploration. Although there was variation between the leading edge and core, the greatest differences lay between males and females from core populations when exposed to a puff of air. We additionally investigated whether females would be less selective of a potential mate at the leading edge. We found marginal support for this and uncovered interesting details regarding P. manueli’s mating system, wherein smaller females were more likely to mate than large ones. Overall, we found boldness and mating behaviour differences between the leading edge and core, but our data suggests greater differences lay between the sexes.
Salazar, A. R., & Rypstra, A. L. (2025). Behavioural variation in the invasive cellar spider Pholcus manueli (Araneae: Pholcidae). Behavioural Processes, 105259. https://doi.org/10.1016/j.beproc.2025.105259