Variation in the level of aggression, chemical and genetic distance among three supercolonies of the Argentine ant in Europe.

In their invasive ranges, Argentine ant populations often form one geographically vast supercolony, genetically and chemically uniform within which there is no intraspecific aggression. Here we present regional patterns of intraspecific aggression, cuticular hydrocarbons (CHCs) and population genetics of 18 nesting sites across Corsica and the French mainland. Aggression tests confirm the presence of a third European supercolony, the Corsican supercolony, which exhibits moderate to high levels of aggression, depending on nesting sites, with the Main supercolony, and invariably high levels of aggression with the Catalonian supercolony. The chemical analyses corroborated the behavioural data, with workers of the Corsican supercolony showing moderate differences in CHCs compared to workers of the European Main supercolony and strong differences compared to workers of the Catalonian supercolony. Interestingly, there were also clear genetic differences between workers of the Catalonian supercolony and the two other supercolonies at both nuclear and mitochondrial markers, but only very weak genetic differentiation between nesting sites of the Corsican and Main supercolonies (F(ST) = 0.06). A detailed comparison of the genetic composition of supercolonies also revealed that, if one of the last two supercolonies derived from the other, it is the Main supercolony that derived from the Corsican supercolony rather than the reverse. Overall, these findings highlight the importance of conducting more qualitative and quantitative analyses of the level of aggression between supercolonies, which has to be correlated with genetic and chemical data.

Characterization and distribution of Pogonomyrmex harvester ant lineages with genetic caste determination.

Genetic caste determination has been described in two populations of Pogonomyrmex harvester ants, each comprising a pair of interbreeding lineages. Queens mate with males of their own and of the alternate lineage and produce two types of diploid offspring, those fertilized by males of the queens' lineage which develop into queens and those fertilized by males of the other lineage which develop into workers. Each of the lineages has been shown to be itself of hybrid origin between the species Pogonomyrmex barbatus and Pogonomyrmex rugosus, which both have typical, environmentally determined caste differentiation. In a large scale genetic survey across 35 sites in Arizona, New Mexico and Texas, we found that genetic caste determination associated with pairs of interbreeding lineages occurred frequently (in 26 out of the 35 sites). Overall, we identified eight lineages with genetic caste determination that always co-occurred in the same complementary lineage pairs. Three of the four lineage pairs appear to have a common origin while their relationship with the fourth remains unclear. The level of genetic differentiation among these eight lineages was significantly higher than the differentiation between P. rugosus and P. barbatus, which questions the appropriate taxonomic status of these genetic lineages. In addition to being genetically isolated from one another, all lineages with genetic caste determination were genetically distinct from P. rugosus and P. barbatus, even when colonies of interbreeding lineages co-occurred with colonies of either putative parent at the same site. Such nearly complete reproductive isolation between the lineages and the species with environmental caste determination might prevent the genetic caste determination system to be swept away by gene flow.

[Dessins de jeunesse, croquis et académies] / [Pierre Loti, Joseph Bernard], dess.

Enregistrement : 00-00-1858 - 00-00-1885

[Pierre Loti] : [les logis flottants] / [Pierre Loti... et al.], dess.[les logis flottants]

Enregistrement : 00-00-1859 - 00-00-1923

[Illustrations de Le figure de la terre... Voyage au Pérou.] / [Non identifié] ; Pierre Bouguer, [aut. du texte]

Comprend : [pl. dépl. en reg. p.CX :] Profil de la cordilière du Pérou, coupée par un plan vertical perpendiculaire à sa longueur. Vue de la cordilière du Pérou aux environs de Quito. [cote : microfilm m 5842/R88883] ; [pl. en reg. p.182 : secteur, instument de mesure astronomique. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [pl.1 à la fin du volume : plan d'un instrument astronomique. Figures géométriques. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [pl.2 à la fin du volume : plan. Figures géométriques. Cadran de mesures astronomiques. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [pl.3 à la fin du volume : instruments de mesures astronomiques. Calculs et figures géométriques. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [pl.4 à la fin du volume : schéma du système de vision. Instruments de mesures astronomioques. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [pl.5 à la fin du volume : figures géométriques. Schéma de cadrans astronomiques. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [pl.6 à la fin du volume : mode de mesure. Instruments de mesures astronomiques. XVIIIè siècle.] Figure de la terre. [cote : microfilm m 5842/R88883] ; [Carte à la fin du volume : Pérou.] Carte des triangles de la méridienne de Quito. [cote : microfilm m 5842/R88883]

Mémoire de Donat Calas pour son père, sa mère et son frère. [À Châtelaine, le 22 juillet 1762.] - Déclaration de Pierre Calas. [À Châtelaine, 23 juillet 1762.]

[Factum. Calas, Jean (1698-1762). 1762]