Genetic Diversity and Structure of Anax imperator Leach, 1815 Populations (Odonata: Aeshnidae) in Ponds at Regional and European Scales

Abstract

Anthropogenic activities cause loss and fragmentation of natural habitats and have strong effects on population maintenance by increasing their isolation. Pond ecosystems are scattered waterbodies that can interact as a network connected by dispersal events of freshwater organisms. Identifying local genetic differentiations and understanding how gene flow occurs across these networks is essential to prevent risks associated with environmental perturbations. This study aimed to investigate genetic diversity and structure of Anax imperator Leach, 1815 populations at both regional and European scales using seven microsatellites markers. Seven populations of A. imperator were sampled in northwestern France and four populations were sampled in Italy (Sicily), Czech Republic, Switzerland and United Kingdom (U.K.). French populations presented a low genetic differentiation indicating a high gene flow and confirming dispersal events of this species between ponds at regional scale. No pattern of isolation by distance was found at the European scale. The populations presented a low genetic differentiation and no pattern of isolation by distance, suggesting historical or current movements of individuals. Only the U.K. population presented a significant genetic differentiation from other European populations, suggesting that the English Channel might act as a barrier to gene flow for A. imperator. However, Bayesian analysis showed that some dispersal events could occur between the U.K. and France (Normandy), probably facilitated by prevailing winds.

Genetic variation reveals complex population structuring of Tomicus piniperda L. (Coleoptera, Scolytidae) in the UK: Implications for management of this important pest

“…Considering the flying abilities of T. piniperda and its widespread presence in north‐western Europe, it is reasonable to assume that it readily crosses the English Channel. Evidence of insect dispersal across the English Channel, regardless of the level of flying abilities, suggests that this might be a particularly important route for species to arrive in the UK, especially those exhibiting traits associated with greater dispersal potential via atmospheric events (Kazachkova et al, 2008; Minot & Husté, 2022; Siljamo et al, 2020). In this regard, the geographically incoherent genetic clustering of the two English sites with the Swiss sample, while the remaining Scottish and Welsh samples clustered with Belgium and the Netherlands directs consideration as to how this pattern is generated and maintained.…”

“…Alternatively, a northern glacial refuge for T. piniperda could have been in Ireland or Scotland, as suggested for Scots pine (Prus-Głowacki et al, 2012;Smout, 2014;T oth et al, 2017). Irish Scots pine is hypothesized to be the origin of the suggests that this might be a particularly important route for species to arrive in the UK, especially those exhibiting traits associated with greater dispersal potential via atmospheric events (Kazachkova et al, 2008;Minot & Husté, 2022;Siljamo et al, 2020). In this regard, the geographically incoherent genetic clustering of the two English The patchy genetic structure among the Scottish, Welsh and English samples indicates that T. piniperda might not disperse extensively between stands in the UK (at small spatial scales).…”

“…Three specific questions were addressed. Firstly, is the English Channel a barrier to dispersal, as found in other insect species (Minot & Husté, 2022; Thomas et al, 2021)? Secondly, is dispersal in the UK limited by environmental factors such as host distribution or physical barriers or is there long‐distance dispersal within the country?…”

A Special Issue on the Diversity, Ecology and Evolution of Dragonflies and Damselflies (Insecta: Odonata)

“…The section on Evolution opens with the article "Genetic diversity and structure of Anax imperator Leach, 1815 populations (Odonata: Aeshnidae) in ponds at regional and European scales" [20], which examines the genetic diversity and structure of Anax imperator populations in Europe using microsatellite markers. The study found high gene flow at both regional and European scales and no pattern of isolation by distance, indicating historical or recent movements of individuals.…”