ABSTRACT
A new, gall-forming eriophyoid mite species is described from Australia. Aculus crassulae sp. nov. was found causing significant leaf deformation in Crassula helmsii (Kirk) Cockayne (Crassulaceae), a semi-aquatic, succulent plant. Native to Australia and New Zealand, this plant is now a highly invasive weed in the United Kingdom and Western Europe. The host specificity of the new mite species, and damage caused to the host plant, infer its potential to be a valuable biological control agent in countries where Australian swamp stonecrop is threatening native flora. The species description provided here, which also includes a revised diagnosis for the genus Aculus, incorporates line drawings and scanning electron micrographs (SEM). This is supplemented by a partial mitochondrial gene sequence of cytochrome c oxidase subunit I (mtCOI) and the sequence was compared with Aculus amygdali Xue Hong and Aculus ichnocarpi (Ghosh Chakrabarati) available in the NCBI database. Pairwise comparison of mtCOI sequences between A. crassulae sp. nov. and two congeneric species revealed 22.6% and 23.1% genetic divergence, respectively.
Subject(s)
Crassulaceae , Mites , Animal Structures , Animals , Australia , Body Size , Europe , New Zealand , Organ Size , United Kingdom , WetlandsABSTRACT
Matrix-assisted laser-desorption and ionization time-of-flight mass spectrometry prepares proteins intact in the gas phase with predominantly a single positive charge. The times-of-flight of charged proteins along a tube held at high vacuum after acceleration in an electrical field are proportional to the square root of the mass-over-charge ratios for the proteins, thereby allowing a mass spectrum to be generated, which can then be used to characterize or identify a protein-containing sample. Several sample-preparation methods are currently available but not all of these are applicable to some forms of fungal biomass and few of these are well suited to the analysis of plant or insect material. We have therefore developed a simplified method that: lyses cells, selectively solubilizes basic proteins, dissolves matrix to a suitable concentration, generates spectra with good intensity and peak richness, costs no more (and generally less) than current methods, and is not constrained in terms of throughput by the availability of centrifuges. Using this method, and a reagent formulation comprising α-cyano-4-hydroxycinnamic acid matrix close to saturation in 60%-65% (v/v) acetonitrile in water containing 2.5% (v/v) trifluoroacetic acid, we have been able to differentiate between strains for a representative subset of aflatoxin-producing and aflatoxin-non-producing strains of Aspergillus fungi, to differentiate between Indian and Pakistani strains of Himalayan balsam rust, to differentiate between closely-related Crassula spp. and regional biotypes of Crassula helmsii, and to differentiate between rubbervine introduced into Australia and Brazil. We have also analyzed fall armyworm and stem-borer samples stored in 70% (v/v) ethanol and old dried insect specimens.
ABSTRACT
Vegetation community composition and the above- and below-ground invertebrate communities are linked intrinsically, though few studies have assessed the impact of non-native plants on both these parts of the community together. We evaluated the differences in the above- (foliage- and ground-dwelling) and below-ground invertebrate communities in nine uninvaded plots and nine plots invaded by the annual invasive species Impatiens glandulifera, in the UK during 2007 and 2008. Over 139,000 invertebrates were identified into distinct taxa and categorised into functional feeding groups. The impact of I. glandulifera on the vegetation and invertebrate community composition was evaluated using multivariate statistics including principal response curves (PRC) and redundancy analysis (RDA). In the foliage-dwelling community, all functional feeding groups were less abundant in the invaded plots, and the species richness of Coleoptera and Heteroptera was significantly reduced. In the ground-dwelling community, herbivores, detritivores, and predators were all significantly less abundant in the invaded plots. In contrast, these functional groups in the below-ground community appeared to be largely unaffected, and even positively associated with the presence of I. glandulifera. Although the cover of I. glandulifera decreased in the invaded plots in the second year of the study, only the below-ground invertebrate community showed a significant response. These results indicate that the above- and below-ground invertebrate communities respond differently to the presence of I. glandulifera, and these community shifts can potentially lead to a habitat less biologically diverse than surrounding native communities; which could have negative impacts on higher trophic levels and ecosystem functioning.
