Preimaginal feeding habits of Dictyogenus fontium (Plecoptera, Perlodidae) in an alpine brook in NW Italy

The feeding habits of Dictyogenus fontium nymphs were investigated in the Rio Olen, an alpine brook in NW Italy. In an analysis of the gut contents of 84 nymphs, we detected evident trophic preferences: Chironomidae (Diptera) were the major component of the prey ingested, independently of their availability in the substratum. Plant detritus and algae were also an important part of the diet of this carnivorous stonefly. The findings are discussed on the basis of ecological considerations

Preimaginal feeding habits of Dictyogenus fontium (Plecoptera, Perlodidae) in an alpine brook in NW Italy

The feeding habits of Dictyogenus fontium nymphs were investigated in the Rio Olen, an alpine brook in NW Italy. In an analysis of the gut contents of 84 nymphs, we detected evident trophic preferences: Chironomidae (Diptera) were the major component of the prey ingested, independently of their availability in the substratum. Plant detritus and algae were also an important part of the diet of this carnivorous stonefly. The findings are discussed on the basis of ecological considerations

Short‐term effects on body condition and size of immunocompetent organs in the hooded crow

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Reproduction of the Crag Martin (Ptyonoprogne rupestris) in relation to weather and colony size

From 1994 to 1999, we investigated how climatic conditions influence the laying dates and number of fledged young of the Crag Martin Ptyonoprogne rupestris, a poorly studied colonial martin that, like other aerial feeding birds, is supposed to be highly dependent on weather conditions. Laying dates were concentrated in May and the first half of June. The mean annual laying date differed significantly among years; however, probably because of the small absolute difference between early and late years, there was no influence on the clutch size nor on the number of fledged young. Mean clutch size was 4.4 ± 0.9 eggs, the hatching rate was 80.2 percent, and the average number of fledged young was 3.1 ± 1.9. Temperature and rainfall in the days before laying and during the incubation period did not influence the breeding success, while in the chick rearing period there was a negative relationship between temperature and number of fledged young. It is supposed that high temperature can negatively influence breeding success through the drying up of small rivers where parents find food (mainly aquatic insects). In our study area the Crag Martins nested solitarily or in small colonies (mean 3.5 ± 1.9 nests). Colony size did not influence the laying date, the clutch size or the number of successfully fledged young

Simultaneous yeast–bacteria inoculum. A feasible solution for the management of oenological fermentation in red must with low nitrogen content

The simultaneous inoculum of yeasts and bacteria is a feasible solution for improving fermentation in wines with a harsh chemical composition, capable of inhibiting microbial activity. Considering the risk of wine spoilage due to lactic bacteria, co-inoculum is suggested in white wines with a low pH. However, climate change has also caused problems in achieving malolactic fermentation in red wines, due to the high concentration of ethanol and the low nutrient content. In this work, 5 pairs of commercial oenological starters were tested in simultaneous fermentation, using 4 red musts with a low nitrogen content, and compared with a traditional winemaking process. The simultaneous inoculum caused a slowdown in the activity of yeasts, although no problems in the accomplishment of alcoholic fermentations were observed. More reliable malolactic fermentation was performed in the co-inoculum trials, while, in traditional winemaking, some failures in the degradation of malic acid were observed. Microbiological analyses agreed with these observations. No differences were found in yeast density during alcoholic fermentation, demonstrating the absence of negative interaction between the yeast and the bacteria. However, simultaneous fermentation is not without risks; the highest increases of acetic acid were noted in the co-inoculum trials. The addition of yeast and bacteria to must with a serious lack of nutrients would appear to be a promising alternative to traditional fermentation; however, careful control of the chemical composition of must is mandatory to obtain reliable microbiological activity in the first stages of winemaking

Effects of immune challenge and supernormal clutch production on egg quality in the red-legged partridge

ABSTRACT Background: Because maintenance of the immune system is thought to be resource-limited, trade-offs between immune function, body condition, and reproductive allocation are expected. Questions: Do females confronted with the simultaneous challenges of immune stimulation and supernormal egg production face a trade-off in terms of self-maintenance (body mass and blood parameters) and/or egg quality? Organism: Red-legged partridge, Alectoris rufa, a precocial bird species with a huge investment in eggs. Methods: We challenged the immune systems of females, before egg laying, with a novel antigen (Newcastle Disease virus vaccine, NDV). We also removed eggs as they were laid, so as to induce supernormal egg production. Conclusion: Compared with the other eggs, the last-laid eggs of hens with supernormal production were smaller, contained less yolk, had a lighter shell, and contained albumen with less lysozyme. However, the immune challenge had no effect on female condition or egg quality. Thus we found no evidence of a trade-off between immune function, body condition, and reproductive allocation

Comparison of European Müller-Thurgau clones grown in Alpine area

Müller-Thurgau (MT) has a remarkable importance for Trentino, a region in the Italian Alps where MT grows on 900 ha in hilly areas from 200 to 800 m a.s.l. Since the '90s, this surface is tripled and now represents the 9 % of the total regional vineyard. This motivated both studies to select new clones fitting for the specific climatic conditions and investigations on the most promising clones already available. Here we present the results of a comparison among 6 clones, one from France (ENTAV 646) and the others from Germany (the classics Wü 7-5 and Gm 18, and the "new entries" Gm 68-10, Gm 68-13 and Gm 68-16). All have been studied in 28 climatic, agronomic and landscape "contexts" (4 years, pergola or upright vertical canopies, plots at various altitudes between 450 and 650 m a.s.l., different agronomical managements ...). In each context, the grapes have been harvested at the same date, 2-3 days before the technological harvest defined by the wineries. The basic analysis of the juice were carried out using a FT-IR approach, while the free and bound varietal aroma compounds, after fixing on ENV+ cartridge and elution, were measured using a GC-MS/MS equipped with a triple quadrupole. The bound fraction was hydrolised using Rapidase Ar2000 (40°C x 12 h). Statistical analysis (Anova, main effects: clone and context; Fisher's LSD test) was performed with STATISTICA v. 8.0. We present the clone performances regarding the sensibility to Botritys and bunch stem necrosis, and several classic vegetative and productive parameters. Moreover, the free and bound aroma composition of the juices is discussed focusing on the compounds with a possible role on the future sensory characteristics of wine. Wü 7-5 and ENTAV 646 confirmed to fit for the region. Gm 18 showed a troubling sensibility to Botrytis. This negative characteristic has been improved in particular in the new clones Gm 68-10 and Gm 68-13, the latter being, in general, the most promisin