Cattle Dung as Vector of Spreading Seeds of Exotic Species in the Flooding Pampa Grasslands (Buenos Aires, Argentina)

2010 ◽  
Vol 47 (1) ◽  
pp. 14-22 ◽  
Author(s):  
Osvaldo R. Vignolio ◽  
Osvaldo N. Fernández
2013 ◽  
Vol 145 (6) ◽  
pp. 647-654 ◽  
Author(s):  
K.D. Floate ◽  
N. Kadiri

AbstractSurveys of dung beetles establish the dominance of exotic taxa associated with cattle dung on native grasslands in southern Alberta, Canada. Of the 12 species recovered, eight were of European origin and comprised 92.2% of the total catch of 187 963 beetles. Most common wereChilothorax distinctus(Müller),Onthophagus nuchicornis(Linnaeus), andColobopterus erraticus(Linnaeus) (Coleoptera: Scarabaeidae). The abundance ofC. distinctushas been known in the region since the 1920s, whereas that ofO. nuchicornisonly was first reported in the 1990s. The abundance ofC. erraticushas not previously been observed in the region and identifies the species as the newest addition to the endemic fauna. The diversity of native species on pastures in southern Canada and adjacent states is depauperate, such that the establishment of European taxa has appreciably increased levels of bioturbation in pasture ecosystems. The success of these exotic species on northern pastures may reflect a level of cold-tolerance greater than that of most native species.


1998 ◽  
Vol 130 (2) ◽  
pp. 131-151 ◽  
Author(s):  
K.D. Floate ◽  
B.D. Gill

AbstractDung beetles (Scarabaeidae) were pitfall trapped at two sites in southern Alberta from 1993 to 1995. A 3-year total of 156 500 specimens representing 17 species was collected. Local assemblages were dominated, in descending order, by the exotic species Onthophagus nuchicornis (Linné), Aphodius prodromus (Brahm), Aphodius distinctus (O.F. Müller), and Aphodius fimetarius (Linné). Aphodius vittatus Say was the most common native species. Although adults were collected from mid-March to mid-November, the activity of individual species either peaked in the spring and again in the fall, or peaked once in spring to midsummer. Maps showing the Canadian distributions for 15 of these species were compiled from examination of collections and published records and identify 10 new provincial records. Most distributions are transcontinental, with the distribution of O. nuchicornis likely expanding only in the last 20–30 years to include Alberta and Saskatchewan. Aphodius erraticus (Linné) and Aphodius ruricola Melsheimer have not been previously reported from British Columbia. Aphodius pinguellus W.J. Brown, Canthon praticola LeConte, and Aphodius coloradensis Horn are restricted to western Canada.


Parasitology ◽  
2012 ◽  
Vol 139 (11) ◽  
pp. 1506-1512 ◽  
Author(s):  
J. A. ETCHEGOIN ◽  
M. J. MERLO ◽  
M. PARIETTI

SUMMARYIn Mar Chiquita coastal lagoon (Argentina), the reefs of the invasive polychaete Ficopomatus enigmaticus (Serpulidae) serve as concentration areas for invertebrates and vertebrates and as potential foci of parasite transmission (mainly digeneans). To analyse the role of F. enigmaticus as facilitator of parasite transmission, and to evaluate the influence of the habitats selected by 2 species of cochliopid snails (Heleobia conexa and Heleobia australis), on the richness and on the prevalence of the digenean assemblages that parasitize them, 1945 snails were collected from 2 sampling sites. The comparisons between larval digenean communities parasitizing both snail hosts revealed significant differences related to the overall prevalence and the prevalence contributed by birds in the snails collected from reefs. These results support the idea that the reefs may increase the number of links between intermediate and definitive hosts of digeneans, facilitating parasite transmission only when the aggregates of F. enigmaticus become the unique habitat of the snail host. This first report of an exotic species acting as facilitator of parasite transmission in an estuarine area highlights the importance of analysing the effects of the assimilation process of exotic species by recently colonized environments (including the possible effects on parasite transmission).


1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.


1998 ◽  
Vol 26 (152) ◽  
pp. 576
Author(s):  
Oscar H. del Brutto Perrone ◽  
José Antonio Bueri ◽  
Antonio Culebras ◽  
Jordi Matías-Guiu Guía ◽  
Marco Tulio Medina Hernández ◽  
...  
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