Systematics, phylogeny and biology of a new genus of Lithocolletinae (Lepidoptera: Gracillariidae) associated with Cistaceae.

The gracillariid genus Triberta gen. nov. (Lepidoptera: Gracillariidae: Lithocolletinae Stainton, 1854) is described to accommodate two species formerly assigned to the genus Phyllonorycter Hübner, 1822: Triberta helianthemella (Herrich-Schäffer, 1861) comb. nov. and T. cistifoliella (Groschke, 1944) comb. nov. Triberta cistifoliella bona sp. is restored from synonymy based on morphological characters. The new genus is biologically associated with the plant family Cistaceae of the order Malvales and is endemic to the Palaearctics. Our molecular analysis of eleven nuclear genes failed to unambiguously place Triberta in the lithocolletine phylogeny, but revealed that this genus is distinct from either clade Phyllonorycter + Cremastobombycia and Cameraria. The distinctiveness of Triberta is also supported by inferred traits in wing venation, micro morphology of the last instar larva, pupa, genital morphology of the adult and life history. A key to the species of Triberta is provided. The interspecific homogeneity in external morphology, coupled with minor differences in genital traits, an apparent narrow specialization on Cistaceae host plants, restricted geographical range and molecular evidence based on multi-nuclear genes jointly suggest that the generic diversification of Triberta is a relatively old phenomenon and driven strongly by host selection.

Genetic races associated with the genera and sections of host species in the holoparasitic plant Cytinus (Cytinaceae) in the Western Mediterranean basin.

* Speciation via race formation is an important evolutionary process in parasites, producing changes that favour their development on particular host species. Here, the holoparasitic plant Cytinus, which has diverse host species in the family Cistaceae, has been used to study the occurrence of such races. * Amplified fragment length polymorphism (AFLP) analyses were performed on 174 individuals of 22 populations parasitizing 10 Cistaceae species in the Western Mediterranean basin. * Neighbour-joining, multivariate ordination analyses, and individual-based Bayesian analyses, clustered Cytinus populations into five well-characterized genetic races that, overall, agreed with the taxonomic sections of their hosts. In the AMOVA, among-races differences accounted for almost 50% of the genetic variation. The isolation-by-distance model was not supported by a Mantel test among Cytinus populations (r = 0.012; P = 0.456). All races showed low within-population genetic diversity, probably as a result of restricted pollen flow aggravated by flowering asynchrony, restricted seed dispersion, or stochastic processes. * The genetic differentiation among the five races of Cytinus is congruent with the view that these races are well-characterized lineages that have evolved independently as a result of selective pressures imposed by their hosts. This pattern, with genetically distinctive groups associated with the infrageneric sections of the host species, has not been reported previously for parasitic angiosperms.