Search results for "Systematics"

Characterization of wine yeast strains of the Saccharomyces genus on the basis of molecular markers: Relationships between genetic distance and geogr…

1996

Summary We identify and characterize 31 Saccharomyces strains from different wine regions, deposited at the Spanish Type Culture Collection, according to mtDNA restriction patterns and chromosomal profiles. By using this kind of information we analyze the correlation between genetic distances and ecological or geographical factors by means of a cluster analysis, assessed by an analysis of the molecular variance (AMOVA). From these analyses, red wine strains are significantly grouped according to their geographic origin, independently of the wine type and the grapevine cultivar, and white wine strians according to ecological factors (wine type of grapevine cultivars). This study also confirm…

Interspecific territoriality in Calopteryx damselflies: the role of secondary sexual characters

2006

Interspecific territoriality is usually interpreted to result from interspecific interference competition, although it may also originate from mistaken species recognition. In the latter case, it may be based on similarity of secondary sexual characters. In the damselfly Calopteryx splendens, males have pigmented wing spots as a sexual character, and males with the largest spots resemble males of another species, Calopteryx virgo. Probably because of this resemblance, C. virgo males are more aggressive towards large- than small-spotted C. splendens males. We examined whether wing spot size of C. splendens males affects territorial interactions between the species. In a removal experiment, t…

Ultraviolet reflection and predation risk in diurnal and nocturnal Lepidoptera

2004

According to our extensive data on Lepidoptera (883 species), UV wing patterns are almost three times more common in nocturnal than in diurnal Lepidoptera. This might be due to predation, because the primary diurnal predators, birds, utilize UV light in foraging and even prefer UV-reflecting prey. To test this hypothesis, we conducted a field experiment with tethered living moths whose wings were artificially manipulated to reflect (UV+, reflection at UV wavelength: 15%) or absorb (UV - ) UV light, keeping longer wavelengths identical. Thus, any difference found in survival rates would be the result of the difference in wing patterns in UV spectrum. Significantly more UV+ moths th…

Microtrichial patterns of the mesothoracic wing surface in Scutelleridae (Hemiptera)

2013

AbstractNew data on forewing microtrichial patterns are presented. Nineteen species representing 19 genera and seven subfamilies of Afrotropical Scutelleridae are investigated using scanning electron microscopy. Four types of microtrichial patterns are recognised. The taxonomic importance of these structures in the Scutelleridae is discussed.

Conservation of Ptilostemon greuteri (Asteraceae), an endemic climate relict from Sicily (Italy): state of knowledge after the discovery of a second …

2022

Ptilostemon greuteri is one of the most endangered and poorly studied woody vascular plant species of the Mediterranean Basin, endemic to Sicily (Italy). Several peculiar traits confer to P. greuteri a character of uniqueness and an enigmatic attractiveness. In fact, at first glimpse the largest individuals of this species remind the most remarkable and peculiar cases of herbaceous genera (e.g., Echium, Senecio) turned woody on insular or insular-like mountain ecosystems. Following the discovery of a second population of this rare species, a project aiming at the study and conservation of P. greuteri was set up. We present here updated information on the distribution, conservation status, b…

Quantitative studies of bird movement: a methodological review

1999

The past several years have seen the development of a number of statistical models and methods for drawing inferences about bird movement using data from marked individuals. It can be difficult to keep up with this rapid development of new methods, so our purpose here is to categorize and review methods for drawing inferences about avian movement. We also outline recommendations about future work, dealing both with methodological developments and with studies directed at hypotheses about bird movement of interest from conservation, management, or ecological perspectives.

Defensive Behavior of Honey Bees Toward Ants

1970

Importance of dispersal and thermal environment for mycorrhizal communities: lessons from Yellowstone National Park

2011

International audience; The relative importance of dispersal and niche restrictions remains a controversial topic in community ecology, especially for microorganisms that are often assumed to be ubiquitous. We investigated the impact of these factors for the community assembly of the root-symbiont arbuscular mycorrhizal fungi (AMF) by sampling roots from geothermal and nonthermal grasslands in Yellowstone National Park (YNP), followed by sequencing and RFLP of AMF ribosomal DNA. With the exception of an apparent generalist RFLP type closely related to Glomus intraradices, a distance-based redundancy analysis indicated that the AMF community composition correlated with soil pH or pH-driven c…

Middle Triassic conodont apparatus architecture revealed by synchrotron X-ray microtomography

2018

Abstract The composition of conodont apparatuses is crucial for understanding the feeding mechanisms of these early vertebrates. However, the multielement apparatus reconstructions of most species remain equivocal because they have been inferred from loose element collections, guided by knowledge from rare articulated ‘bedding plane assemblages’ and fused clusters, often from distantly related taxa. Even these natural assemblages can be difficult to interpret because the component elements can be closely juxtaposed or embedded in matrix, making it hard to discern the morphology of each element and their relative positions within the architecture of the feeding apparatus. Here we report five…

The diversity and evolution of chelicerate hemocyanins

2012

Abstract Background Oxygen transport in the hemolymph of many arthropod species is facilitated by large copper-proteins referred to as hemocyanins. Arthropod hemocyanins are hexamers or oligomers of hexamers, which are characterized by a high O2 transport capacity and a high cooperativity, thereby enhancing O2 supply. Hemocyanin subunit sequences had been available from horseshoe crabs (Xiphosura) and various spiders (Araneae), but not from any other chelicerate taxon. To trace the evolution of hemocyanins and the emergence of the large hemocyanin oligomers, hemocyanin cDNA sequences were obtained from representatives of selected chelicerate classes. Results Hemocyanin subunits from a sea s…