94 resultados para Rare plants


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Neotropical orchid bees (Euglossini) are often cited as classic examples of trapline-foragers with potentially extensive foraging ranges. If long-distance movements are habitual, rare plants in widely scattered locations may benefit from euglossine pollination services. Here we report the first successful use of micro radio telemetry to track the movement of an insect pollinator in a complex and forested environment. Our results indicate that individual male orchid bees (Exaerete frontalis) habitually use large rainforest areas (at least 42-115 ha) on a daily basis. Aerial telemetry located individuals up to 5 km away from their core areas, and bees were often stationary, for variable periods, between flights to successive localities. These data suggest a higher degree of site fidelity than what may be expected in a free living male bee, and has implications for our understanding of biological activity patterns and the evolution of forest pollinators.

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Many insect species vary in their degree of foraging specialisation, with many bee species considered polyphagic (polylectic). Wild, non-managed bee species vary in their conservation status, and species-specific biological traits such as foraging specialisation may play an important role in determining variance in population declines. Current agri-environment schemes (AESs) prescribe the introduction of flower seed mixes for agricultural systems to aid the conservation of wild bees. However, the extent to which flower combinations adequately meet bee foraging requirements is poorly known. We quantitatively assessed pollen use and selectivity using two statistical approaches: Bailey's Intervals and Compositional Analysis, in an examplar species, a purportedly polylectic and rare bee, Colletes floralis, across 7 sites through detailed analysis of bee scopal pollen loads and flower abundance. Both approaches provided good congruence, but Compositional Analysis was more robust to small sample sizes. We advocate its use for the quantitative determination of foraging behaviour and dietary preference. Although C. floralis is polylectic, it showed a clear dietary preference for plants within the family Apiaceae. Where Apiaceae was uncommon, the species exploited alternative resources. Other plant families, such as the Apiaceae, could be included, or have their proportion increased in AES seed mixes, to aid the management of C. floralis and potentially other wild solitary bees of conservation concern. © 2011 The Authors. Insect Conservation and Diversity © 2011 The Royal Entomological Society.

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The co-occurrence of two rare recessive genetic conditions in apparently unrelated individuals or families is extremely rare. Two geographically distant and apparently unrelated families were identified in which individuals were simultaneously affected by two rare recessive mendelian syndromes, Papillon-Lefevre syndrome and type 1 oculocutaneous albinism. The families were tested for mutations in the causative genes, cathepsin C (CTSC) and tyrosinase (TYR), respectively, by direct sequencing. To assess the relationship of the two families, both families were tested for polymorphisms at eight microsatellite markers spanning both CTSC and TYR loci. Independent mutations (c.318-1G-->A and c.817G-->C/p.W272C) were identified in CTSC and TYR, respectively, that were shared by the affected individuals in both families. The two affected genes lie close together on chromosome bands 11q14.2-14.3, and studies with linked genetic markers suggested that the families shared a small chromosomal segment carrying both mutations that had been transmitted intact from a remote common ancestor. The co-occurrence of the two rare diseases in multiple families depends on their shared chromosomal location, but not on any shared pathogenic mechanism.