The interplay of ecological and evolutionary processes in the spread of the invasive spider Mermessus trilobatus (Araneae: Linyphiidae) in Europe

• Applicant: Professor Dr. Martin Entling
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 418363770

• Final Report Year: 2023

Final Report Abstract

Only a few decades after its introduction from North America, Mermessus trilobatus has become one of the most abundant spiders in Central European grasslands. The expansion of its invaded range has accelerated from about 150 km in the 1980s to some 400 km in the last decade. We sampled live Mermessus individuals from several European countries to investigate if their mobility and other traits have evolved in the course of their invasion history. Furthermore, we performed breeding and behavioural experiments to study interactions with native species. The propensity of aerial dispersal proved strongly heritable. As expected, dispersal propensity was higher in newly invaded areas than longer established populations. This indicates the accumulation of dispersive genotypes at the invasion front, which can explain the increased speed of range expansion over time. However, the successful establishment of M. trilobatus in native communities remains unexplained since they appear neither more tolerant to disturbance, more competitive, nor more successful in avoiding predators compared to native Linyphiid species. So far, an increased numbers of offspring per female appears to be the only factor that could explain the high establishment success in European spider assemblages.

Publications

• Unexpected sensitivity of the highly invasive spider Mermessus trilobatus to soil disturbance in grasslands. Biological Invasions, 23(1), 1-6.
  Narimanov, Nijat; Kempel, Anne; van Kleunen, Mark & Entling, Martin H.
  
• Disentangling the roles of electric fields and wind in spider dispersal experiments. The Journal of Arachnology, 49(3).
  Narimanov, Nijat; Bonte, Dries; Mason, Paul; Mestre, Laia & Entling, Martin H.
  
• Prey naïveté rather than enemy release dominates the relation of an invasive spider toward a native predator. Ecology and Evolution, 11(16), 11200-11206.
  Narimanov, Nijat; Hatamli, Kamal & Entling, Martin H.
  
• Accelerated invasion through the evolution of dispersal behaviour. Global Ecology and Biogeography, 31(12), 2423-2436.
  Narimanov, Nijat; Bauer, Tobias; Bonte, Dries; Fahse, Lorenz & Entling, Martin H.
  
• Heritability of dispersal in a rapidly spreading invasive spider. Animal Behaviour, 183, 93-101.
  Narimanov, Nijat; Bonte, Dries & Entling, Martin H.