Ground Beetles in a Changing World: Communities in a Modified Wetland Landscape

Wetlands are being increasingly affected by anthropogenic activities worldwide. The Lower Delta of the Paraná River, one of the most important wetlands in Argentina, has been profoundly altered because most of the natural environments were drained or diked to make them suitable for different agricultural activities. As a result, the landscape is characterized by a mosaic of Salicaceae afforestations of different ages interspersed with patches of secondary forests and grazing grasslands. The high susceptibility of Carabidae and Aphodiidae to natural and human-induced disturbances and management practices is reflected by changes in their spatiotemporal distribution. We performed a 1-year study to analyze and compare beetle's communities inhabiting different habitat types in this modified wetland landscape. A total of 58 beetle species were recorded, of which 48 were carabids and 10 aphodids. Although species richness and diversity were higher in productive habitats (afforestations and grasslands) than in secondary forests, hydrophilic species were only found in the latter. Community parameters varied seasonally. Our results indicate a close relationship between wetland beetle communities and vegetation cover in each habitat type. Human activity increases heterogeneity across this landscape, which favors the colonization of new species but causes the loss or displacement of autochthonous species. The secondary forests could serve as alternative habitats for beetles typical of humid environments. We propose the maintenance of the current heterogeneous mosaic to favor the diversity of ground beetles and the implementation of changes in water management for the benefit of hydrophilic beetle species.

Two new species of Brueelia (Phthiraptera: Philopteridas s. l.) parasitic on two species of Phrygilus (Aves: Emberizidae) from Chile

Two new species of the genus Brueelia Kéler, 1936 are described of two species in the genus Phrygilus Cabanis, 1844 from Punitaqui, Coquimbo, IV Región, Chile: Phrygilus gayi (Gervais, 1834) and P. fruticeti (Kittlitz, 1833). Descriptions were made in a comparative form, adding comments on their relatives, as well as an account of all Brueelia species known to infest South American Emberizine finches.

Identification of Microthoracius mazzai (Phthiraptera: Anoplura) as an economically important parasite of alpacas

The hematophagous sucking louse Microthoracius mazzai Werneck, 1932, is redescribed and identified as a parasite of alpacas, Lama pacos L. Specimens were collected on animals 10-14 mo old, located on a large community farm at 4,600 m above sea level in the Peruvian Andes. In total, 26 scanning electron microscope (SEM) figures are included that highlight salient and differential characteristics, especially the unique elongated spindle-shaped head, which is almost as long as its abdomen. Alpacas, 1 of the 4 species of South American camelids, are important for their production of high-quality wool in the Andes Mountain range countries, especially Peru and Bolivia; to a lesser degree Chile; and more recently Argentina, where breeding and disease control programs are receiving increased technical support. Information is given on the prevalence of lice infestations in the flock, clinical signs, and economic losses. We report the efficacy of moxidectin (SC, 200 mcg/kg, b.w.) in a repeated treatment program of 7-10 d, which is currently used for mange control in these ruminants.

[Prevalence and seasonal variation of Pediculosis capitis in children and the young population of the health region, Buenos Aires, Argentina]

The prevalence of the parasitic disease Pediculosis capitis was studied over a period of one year from 1-8-1992 to 31-7-1993, in Sanitary Region XI of the Buenos Aires province, Argentina which is composed of 15 districts located on the ENE, and in other areas under the influence of the Hospital Interzonal de Agudos, Especialidad Pediatría "Sup. Sor María Ludovica" de Plata, center of this Sanitary Region. A total number of 552 individuals of from medium to medium low social level of the child population of from 0 to 16 years of age were sampled at random over 52 consecutive weeks. All individuals who actually had the parasite at the time of examination were considered as positive for this disease. The results are expressed in terms of prevalence and its monthly and seasonal variations analyzed. Prevalence showed high values during all months, the lowest being in February (12%) and the highest in August (56.8%), the annual mean being of 38.04% (+/- 4.05%). Seasonally, its lowest value occurred in the summer (16.8%), the values for the remaining seasons being very similar to one another, but always higher than 38%.