Rapid genetic and ecological differentiation during the northern range expansion of the venomous yellow sac spider Cheiracanthium punctorium in Europe

Abstract

Although poleward range expansions are commonly attributed to global change, a complex interaction of ecological and evolutionary factors might contribute to expansion success. Here, we study the expansion of the yellow sac spider Cheiracanthium punctorium, a medically important species in Central Europe. Using microsatellite markers and DNA sequences, morphological and climate niche analyses, we identify factors associated with the spider's expansion success. Our results indicate that the species' initial expansion has been triggered by environmental change and preadaptation in the source populations. However, despite extensive gene flow, expanding populations maintain genetic and morphological differentiation from native ones, which is correlated with climatic niche differences. Moreover, expanding spiders might have temporarily escaped an eggsac parasite that causes high mortality in the native range. Hence, our results paint a complex picture of diverse factors associated with expansion success. We speculate that expanding populations might be capable of adapting to novel ecological conditions in northern Europe. This could allow a substantial range expansion, much farther than by environmental change alone. Our distribution model predicts that the spider will soon massively spread over most of northern Europe, bringing along considerable health concerns.

Spatial and temporal heterogeneity in climate change limits species' dispersal capabilities and adaptive potential

“…Recent advances have demonstrated that rapid, directional climatic change is not necessarily the insurmountable challenge for populations it was once believed to be (Kovach et al 2012, Gill et al 2013, Bataillon et al 2016, Franks et al 2016, Krehenwinkel et al 2016, Oexle et al 2016. Instead the difficulty posed by climate change is that rates of climatic change can vary both across time within a single region, as well across regions during a single time period (Ebi et al 2016).…”

“…For instance, following the extremely cold midwinter conditions experienced by much of continental North America in January-February 2014, surviving green anoles Anolis carolinensis exhibited both marked increases in their cold tolerances and signatures of selection across the genome (Campbell-Staton et al 2017). Similarly, rapid plastic and evolutionary responses to global climate change have already been observed across taxa ranging from migratory birds (Gill et al 2013) to anadromous fish (Kovach et al 2012), arthropods (Krehenwinkel et al 2016), annual plants (Franks et al 2016), and soil (Bataillon et al 2016) and aquatic invertebrates (Oexle et al 2016). In fact, rapid, directional climatic changes may even facilitate rapid responses (Phillips et al 2016).…”

Steatoda nobilis, a false widow on the rise: a synthesis of past and current distribution trends

“…Another possible reason for the spider's expansion success is evolutionary adaptation, e.g., an ecological niche expansion (Guisan et al 2014) in the British populations. This has been suggested in Argiope bruennichi (Scopoli, 1772) and Cheiracanthium punctorium (Villers, 1789), two spider species which have naturally expanded their distribution in the last decades (Krehenwinkel and Tautz 2013;Krehenwinkel et al 2015Krehenwinkel et al , 2016. The emergence of such adaptations can require extended times, leading to a characteristic lag phase of range expansion (Lee 2002;Aikio et al 2010).…”

Two hymenopteran egg sac associates of the tent-web orbweaving spider, Cyrtophora citricola (Forskål, 1775) (Araneae, Araneidae)

“…Although egg parasitism or predation in spiders has received little attention, case studies suggest it may be common in native ranges (e.g., van Wingerden 1973;Rollard 1985;van Baarlen et al 1994;Dinter 1996;Sacher 2001;Finch 2005;Leborgne and Pasquet 2005;Krehenwinkel et al 2016;Wawer and Kostro-Ambroziak 2016), resulting in high mortality rates in parasitized egg sacs (Finch 2005;Krehenwinkel et al 2016;Wawer and Kostro-Ambroziak 2016). Smith (1982) documented fewer offspring of the orbweaver spider Philoponella oweni (Chamberlin 1924) owing to parasitism by the pteromalid wasp Arachnopteromalus dasys Gordh, 1976.…”