The gall-inducing habit has evolved multiple times among the eriococcid scale insects (Sternorrhyncha : Coccoidea : Eriococcidae)

The habit of inducing plant galls has evolved multiple times among insects but most species diversity occurs in only a few groups, such as gall midges and gall wasps. This phylogenetic clustering may reflect adaptive radiations in insect groups in which the trait has evolved. Alternatively, multiple independent origins of galling may suggest a selective advantage to the habit. We use DNA sequence data to examine the origins of galling among the most speciose group of gall-inducing scale insects, the eriococcids. We determine that the galling habit has evolved multiple times, including four times in Australian taxa, suggesting that there has been a selective advantage to galling in Australia. Additionally, although most gall-inducing eriococcid species occur on Myrtaceae, we found that lineages feeding on Myrtaceae are no more likely to have evolved the galling habit than those feeding on other plant groups. However, most gall-inducing species-richness is clustered in only two clades (Apiomorpha and Lachnodius + Opisthoscelis), all of which occur exclusively on Eucalyptus s.s. The Eriococcidae and the large genus Eriococcus were determined to be non-monophyletic and each will require revision. (C) 2004 The Linnean Society of London.

The Western Alps from the Jurassic to Oligocene: spatio-temporal constraints and evolutionary reconstructions

Despite extensive research in the last 150 years, the regional tectonic reconstruction of the Western Alps has remained controversial. The curved orogenic belt consists of several ribbon-like continental terranes (Sesia/Austroalpine, Internal Crystalline Massifs, Brianconnais), which are separated by two or more ophiolitic sutures (Piemonte, Valais, Antrona?, Lanzo/ Canavese?). High-pressure (HP) metamorphism of each terrane occurred during distinct orogenic episodes: at similar to65 Ma in the Sesia/Austroalpine, at similar to45 Ma in the Piemonte zone and at similar to35 Ma in the Internal Crystalline Massifs. It is suggested that these events reflect individual accretionary episodes, which together with kinematic indicators and the speed and direction of plate motions, provide constraints for the discussed reconstruction model. The model involves a prolonged orogenic history that took place during relative convergence of Europe and Adria (here considered as a promontory of the African plate). The first accretionary event involved the Sesia/Austroalpine terrane. Final closure of the Piemonte Ocean occurred during the Eocene (similar to45 Ma) and involved ultra-high-pressure (UHP) metamorphism of the Piemonte oceanic crust. Incorporation of the Brianconnais terrane in the accretionary wedge occurred thereafter, possibly during or after subduction of the Valais Ocean in the late Eocene (45-35 Ma). This subduction was terminated at ca. 35 Ma, when the Internal Crystalline Massifs (i.e. the assumed internal parts of the Brianconnais terrane) were buried into great depths and underwent HP and UHP metamorphism. (C) 2004 Elsevier B.V. All rights reserved.

Geospatial clustering in data-rich environments: Features and issues

Geospatial clustering must be designed in such a way that it takes into account the special features of geoinformation and the peculiar nature of geographical environments in order to successfully derive geospatially interesting global concentrations and localized excesses. This paper examines families of geospaital clustering recently proposed in the data mining community and identifies several features and issues especially important to geospatial clustering in data-rich environments.