Correlations between observed dispersal capabilities and patterns of genetic differentiation in populations of four aquatic insect species from the Arizona White Mountains, U.S.A.

Abstract

SUMMARY 1. Dispersal ability is an important ecological factor that can influence population structure. In an attempt to determine the extent that the pattern of genetic differentiation is correlated with dispersal ability in stream‐dwelling aquatic insects, we used the amplified fragment length polymorphism (AFLP) technique to characterise genetic variation in four aquatic insect species: Gumaga griseola (Trichoptera: Sericostomatidae), Helicopsyche mexicana (Trichoptera: Helicopsychidae), Psephenus montanus (Coleoptera: Psephenidae) and Ambrysus thermarum (Hemiptera: Naucoridae). Individuals were sampled from several sites within two adjacent catchments in the Arizona White Mountains. In addition to the genetic analyses, a 20‐week‐long trapping study was used to determine the relative dispersal ability of adults of the four species examined. 2. We obtained hierarchical indicators of genetic differentiation for catchments, sites within catchments and sites across the region examined. Overall, average estimators of genetic differentiation (F‐statistics) were consistent with direct observations of organismal movement, although it was our direct observations on adult insect flight that permitted us to interpret our results correctly. This was because of the fact that a lack of genetic differentiation across watersheds can be interpreted in two ways. 3. In contrast to F‐statistics, patterns of genetic isolation by distance for each species more clearly reflected dispersal ability, suggesting that such analytical approaches provide less ambiguous information about the importance of gene flow in the hierarchical partitioning of genetic variation in stream organisms.

The aquatic leaf beetle Macroplea mutica (Coleoptera: Chrysomelidae) in Europe: Population structure, postglacial colonization and the signature of passive dispersal

“…While it is not known when Macroplea became fully aquatic, the time span is shorter than the one other "typical" aquatic invertebrates had in which to evolve their life history traits (aquatic Coleoptera and Hemiptera: > 150 Mya; Grimaldi & Engel, 2005), particularly a means of dispersal (Verberk et al, 2008a, b). Many of them show less population structure due to their habitual dispersal (Hughes et al, 2000;Wilcock et al, 2001;Miller et al, 2002;Brändle et al, 2005;Beebee, 2007;Zickovich & Bohonak, 2007). The clear differentiation between Macroplea populations recorded is similar to that in terrestrial situations in which there are natural or man made barriers to dispersal (Takami et al, 2004;Vandewoestijne & Baguette, 2004;Keyghobadi et al, 2005) or immobility (flightlessness) of the organisms (Brouat et al, 2003;Keller et al, 2004;Saitoh et al, 2007;Drees et al, 2008).…”

“…For the analysis the method of amplified fragment length polymorphism (AFLP; Vos et al, 1995) was chosen because of its proven applicability for insect population genetic studies (McMichael & Prowell, 1999;Parsons & Shaw, 2001;Tan et al, 2001;Miller et al, 2002;Salvato et al, 2002;van der Wurff et al, 2003;Kazachkova et al, 2004) and practical advantages (Vos et al, 1995;Mueller & Wolfenbarger, 1999).…”

Population structure of Macrobrachium australiense (Decapoda: Palaemonidae) in Western Queensland, Australia: the role of contemporary and historical processes

“…Some aquatic insects possess a flying stage in their life cycle, which allows them to disperse across drainage boundaries (Hughes et al, 1998;Miller et al, 2002). However, movements of continuously aquatic freshwater species are very much limited by the physical nature and arrangement of the riverine system (Hurwood and Hughes, 2001;McGlashan and Hughes, 2001) and often species with apparently good dispersal abilities present surprisingly high levels of population subdivision (Hughes et al, in review;Hughes and Hillyer, 2003).…”

Mitochondrial DNA signatures of restricted gene flow within divergent lineages of an atyid shrimp (Paratya australiensis)

“…Generally, it appears that, for groups such as insects possessing a flying stage within their life history, dispersal is widespread within and between drainages (eg Schmidt et al, 1995;Hughes et al, 1998;Miller et al, 2002), although there are exceptions such as blepheracerid midges, which show very restricted dispersal patterns even among streams in the same subcatchment (Wishart and Hughes, 2003).…”