Genetic differentiation and dispersal among populations of the damselfly Lestes viridis (Odonata)

We investigated genetic differentiation among 8 populations of the protected damselfly Lestes viridis (Vander Linden, 1825) in permanent ponds in northern Belgium by means of allozyme electrophoresis and isoelectric focusing, and estimated levels of gene flow using F-statistics. In addition, we did a capture-mark-recapture experiment to estimate direct levels of gene flow. Our aim was to test whether populations of L. viridis represented a single, large panmictic population or formed a series of demographically isolated populations, which may be defined as appropriate management units (MU). None of the marked individuals moved among the ponds, indicating a strong fidelity for adults to their breeding pond. Only 1 population was genetically strongly differentiated, whereas little or no differentiation was observed among the 7 other ponds. Absence of adult dispersal but genetic homogeneity between ponds thus suggested substantial teneral dispersal. We observed large heterozygote deficiencies at 2 loci (Fdh and Est). Significant differences in allele frequencies among ponds suggests that populations of L,. viridis in northern Belgium may consist of >1 MU. Management plans for conservation should therefore take into consideration the presence of several MUs in this species.status: publishe