Life history, biogeography, and the potential for allochronic diversification in the relict dragonfly Tanypteryx hageni (Odonata: Petaluridae)

The dragonfly family Petaluridae is a relict group with eleven extant species, distributed in Australia, New Zealand, Japan, Chile and the Pacific Northwest and Appalachian regions in North America.  These species have ecologies quite different from other dragonflies: their aquatic larval stage lives in flooded burrows in fens, often at high elevation.  Larvae take as many as five years to develop into an adult, but adults fly for only a few weeks.  With this life history pattern, individuals from different cohorts within the same fen are not likely to interbreed (as they emerge as adults in different years), but individuals from the same cohort in different fens might be able to mate, if the adults can disperse between larval habitats.  We are then left with the question: what is a ‘population’ in this group?  We address this question through population genetic analysis of the species Tanypteryx hageni, found in northern California and Oregon in the US.