Development of 18 novel polymorphic microsatellites from Coccinella septempunctata and cross-species amplification in Coccinellidae species

The seven spot ladybird (Coccinella septempunctata), a widely spread coccinellid in the Palearctic region, introduced in USA where it is recently identified as invasive, is used as biological control agent. Its taxonomic status, with peripheral populations phenotypically distinct, is not well defined. Understanding its population genetic structure is crucial to investigate its evolutionary history, local adaptation in peripheral populations, dispersal and invasion dynamics. In this context, we isolated and characterised, from microsatellite enrichment and next-generation sequencing, 18 polymorphic microsatellite markers. Genetic variation was assessed from four geographically distant populations. The number of alleles ranges from two to 15 per locus and per population and the observed and expected heterozygosities are similar whatever the population (0.53 and 0.640, respectively). High successful cross-amplification in additional 21 species, belonging to five coccinellid subfamilies, suggests their broad application.