Rhysida longipes (Scolopendromorpha: Scolopendridae), an unusual prey of Physocyclus globosus (Araneae: Pholcidae)

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  Rhysida longipes (Scolopendromorpha: Scolopendridae), an unusual prey of Physocyclus globosus (Araneae: Pholcidae) Abstract A very young centipede Rhysida longipes (Newport, 1845), approximately 12 mm in total length, is recorded as prey of the synanthropic common spider Physocyclus globosus (Tackzanowski, 1874). The episode was observed into an urban residence in San Antonio de los Baños, Artemisa Province, Cuba. In Cuba this is the first time that a spider is recorded preying upon a centipede. Acknowledgment: I extend my sincere gratitude to Luis F. De Armas for kindly providing me with the complete paper. ¡Enhorabuena, Luis! ARMAS, L. F. DE 2025. Rhysida longipes (Scolopendromorpha: Scolopendridae), an unusual prey of Physocyclus globosus (Araneae: Pholcidae). Boletín de la Sociedad Entomológica Aragonesa, 77: 86–87. 

Simulating a hybridization event of a range-expanding sexual cannibal (Argiope bruennichi)

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Simulating a hybridization event of a range-expanding sexual cannibal (Argiope bruennichi)

Abstract

Hybridization plays an important role in animal speciation. Mediterranean populations of the Palaearctic wasp spider Argiope bruennichi have recently undergone a range expansion northwards. Adaptation to colder winters was facilitated by introgressed alleles derived from Asian populations, hence the resulting hybrids were able to expand geographically. Argiope bruennichi exhibits a highly complex mating system that includes strong sexual conflict and predisposes the species to behaviours that could facilitate directed hybridization and hybrid stabilization. To test this, we simulated a hybridization event with European and Asian spiders and a backcrossing event with southern and northern European spiders by conducting mate choice experiments and mating trials. We found pronounced differences in the cannibalism and monopolization successes between the populations. Asian male spiders were more successful in monopolizing European females than their European conspecifics and more successful than European males with Asian females. This would have led to an increased proportion of these specific offspring in the hybrid population. Our results suggest the mating system as a driving factor in the directional hybridization of Asian males and European females and the establishment of new northern European populations of A. bruennichi. We found no influences of the mating system on the stabilization of the resulting hybrid populations, probably owing to cold survival adaptations being a more important factor.


Sebastian Franke, Jutta M Schneider, Simulating a hybridization event of a range-expanding sexual cannibal (Argiope bruennichi), Biological Journal of the Linnean Society, 2024;, blae018, https://doi.org/10.1093/biolinnean/blae018