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Fourteen microsatellite loci were isolated and their level of polymorphism characterized in two populations of the facultatively polygynous plant-ant Petalomyrmex phylax (Formicinae). High levels of within-population variation were observed at most loci, with number of alleles ranging from two to 15, and heterozygosity from 0.050 to 0.925. Cross-species amplification of these loci was also tested in four plant-ant species belonging to three other genera, Aphomomyrmex , Cladomyrma ( both Formicinae) and Cataulacus (Myrmicinae).

Microsatellite loci were isolated from enriched partial genomic libraries of Acyrthosiphon loti and Acyrthosiphon pisum . Twenty of those loci were characterized in A. pisum . Fifteen of those loci were polymorphic. Genetic diversity varied across loci, allele repeat number ranging from two to 15, and observed heterozygosity from 0.1 and 0.96. An additional eight microsatellite loci originally isolated from other aphids but cross-priming with A. pisum showed polymorphism as well. Allele size ranged from three to 9 and observed heterozygosity from 0.43 to 0.84. Overall, we present 23 microsatellite loci that can be used to reveal polymorphism in pea aphids.

Eleven microsatellite loci were isolated from the plant-ant Cataulacus mckeyi (Hymenoptera: Myrmicinae) and their polymorphism was characterized. High levels of within-population variation were observed at most loci, with number of alleles ranging from one to 16, and heterozygosity from 0 to 0.929 per population sample. Cross-species amplification of these loci was also tested in four other species of the ant genus Cataulacus.

We isolated eight microsatellite loci in the black grouse (Tetraonidae). Polymorphism ranged from 2 to 15 alleles (48 individuals from the same locality examined). Cross-specific amplifications suggests that some of these microsatellites may be used in other tetraonids and, to a lesser extent, in some other phylogenetically more distant galliforms.

Microsatellite loci were isolated from Plasmopara viticola (Oomycetes), the causal agent of downy mildew of grape, one of the most damaging fungal diseases of grapevine worldwide. Seven polymorphic loci were obtained from an enriched partial genomic library. A low genetic diversity was observed at all loci, with a mean observed allele number of 3.75 and an observed heterozygosity ranging from 0.074 to 0.547. Cross-amplification tests on three closely related taxa indicated that two loci could be used in other Oomycetes species. These microsatellite loci were proved to be useful for population genetic analysis.

Allelic variation at eight microsatellite loci was used to assess the levels of genetic differentiation between seven natural populations of black grouse (Tetrao tetrix) in the French Alps spaced along a 250 km south-north transect. Whatever the population or locus, genotype frequencies did not deviate significantly from expected Hardy-Weinberg frequencies and no significant between-locus linkage desequilibrium was detected. Observed levels of genotypic variation were statistically significant with maximum Fst values reaching 10% for the most distant populations (250 km). An isolation-by-distance effect was detected suggesting, as expected from data on marked birds, that black grouse populations in the French Alps are interconnected by dispersal.

Wolbachia are endosymbiotic bacteria responsible for thelytoky in several parasitoid hymenopteran genera. After finding these micro-organisms in some populations of Diplolepis spinosissimae (Hymenoptera: Cynipidae) where they are responsible for thelytoky through gamete duplication, we searched for Wolbachia spp. using specific PCR primers in nineteen other species of the Rhoditini tribe (rose gallwasps) and eight species of the 'Aylacini' tribe (gallwasps associated with herbaceous plants). Wolbachia were found in twelve Rhoditini species and four 'Aylacini' species. The most infected species have very few males (spanandry) and the thelytoky of infected species/arrhenotoky of uninfected species is confirmed by previous research based on the sex of the offspring of virgin females. Phylogenetic analyses based on the partial Wolbachia ftsZ gene sequences indicate that some strains associated with closely related gallwasps are phylogenetically distant, suggesting that cynipids have been affected by several infection events. In contrast, the five infected European species of Diplolepis harbour the same strain of Wolbachia.

According to the present classification, the family Agaonidae contains all fig pollinators as well as five subfamilies of non-pollinating fig wasps. The molecular phylogeny of the family was reconstructed using partial sequences of the 28S rRNA (D1 and D2 domains). Our results show that the family Agaonidae is not monophyletic. As a consequence, we restrict the famiy to the pollinator clade, and assign the non-pollinating subfamilies to various chalcid families. Sycoecinae, Otitesellinae and Sycoryctinae are included in Pteromalidae, whereas Sycophaginae and Epichrysomallinae are left unclassified and will require more in-depth morphological studies. Moreover, we proved that the fig pollination syndrome evolved only once, early in group history. The resource due to the fig-pollinator mutualism has secondarily been colonized independently by different Chalcid lineages.

C. solieri is an endangered species of Carabidae which is mostly associated with humid forests of the Alps, in Prance and in Liguria (Italy). We reanalysed morphological data published by Bonadona and compared the results to the molecular data set presented here. We used partial sequences of the mitochondrial cytochrome b gene and seven microsatellite loci to evaluate genetic diversity among and between populations and to propose a phylogeographic scenario. We recognised two basic entities, considered as subspecies, which probably colonised the present distribution range from two main refugia (in France and in Italy). There is no strict agreement between morphological and molecular data and we propose that hybridisation and introgres-sion between the two subspecies have led to the observed patterns of distribution of the characters. Our results show that sampled populations differ significantly in microsatellite allele frequencies even though some populations are < 15 km apart. Gene flow estimates between the 19 sampled populations indicated very restricted exchange. This is in agreement with the low vagility observed for most species of Carabus. Consequently, the Solier’s Carab is genetically structured on an extremely fine scale, and local population within a definite forest should be considered as management units. In the light of our data on C. solieri we discuss the usefulness, when hybridisation occurs, of the two main criteria usually quoted for identifying candidate populations for conservation management (uniqueness and diversity) and give some conservation recommendations for C. solieri.

Cynipids are known to use various reproductive modes (arrhenotoky, thelytoky and strict cyclical parthenogenesis), but the mechanism remains unknown. We have studied the reproductive system of a rose gallwasp, Diplolepis spinosissimae, which was found to exhibit two different reproductive systems according to the population. In eight out of the ten populations studied, all along the Atlantic coast, D. spinosissimae is thelytokous. Males are extremely rare, and all females are homozygous at three microsatellite loci. 'Obligate homozygous parthenogenesis' was found to be strictly associated with the presence of the endosymbiotic bacterium Wolbachia sp. In the two remaining populations, deprived of Wolbachia, D. spinosissimae reproduced by arrhenotoky as indicated by the larger frequency of males and heterozygosity of females. Allelic diversity, although not zero, was highly reduced in the coastal populations, as a consequence of thelytoky and gamete duplication. We hypothesize that mating of uninfected males with infected females during the first generations after an infection event could explain the small but significant amount of polymorphism observed in those populations. The high level of differentiation indicates a low gene flow, even between geographically close coastal populations.