نتایج جستجو برای: bombus
تعداد نتایج: 1281 فیلتر نتایج به سال:
1. Declines in abundance and diversity of bumble bees ( Bombus spp.) in Europe have been linked to agricultural intensification and the resulting loss of suitable foraging and nesting habitats. Environmental Stewardship (ES) is a new scheme in England offering the opportunity to restore habitats of value for these important pollinators to agricultural land. Scientific evaluation of the options ...
Behavioural interactions are often analysed in terms of their costs and benefits to the actors [Hamilton, (1964) J. Theor. Biol.7 1-16; Gadagkar, (1993) Trends Ecol. Evol.8 232-234; Foster et al., (2001) Ann. Zool. Fenn.38 229-238]. Using the bumblebee Bombus terrestris, we wish to distinguish between two possible determinants of interaction behaviour between conspecifics, namely kin-directed b...
Variation in the availability of food resources over space and time is a likely driver of how landscape structure and composition affect animal populations. Few studies, however, have directly assessed the spatiotemporal variation in resource availability that arises from landscape pattern, or its effect on populations and population dynamic parameters. We tested the effect of floral resource a...
Ninety three bumble bees belonging to the genus Bombus, subgenus Pyrobombus (three Bombus vagans, seven Bombus bimaculatus, 17 B. sandersoni and 68 B. impatiens) from Great Smoky Mountains National Park were examined for microsporidia. Light microscopy of calcoflour and trichrome-stained smears, and PCR revealed infection with N. bombi in one specimen each of B. sandersoni and B. impatiens. Siz...
We present new DNA sequence data (12S, 16S, and opsin gene fragments) and morphological characters of the male genitalia for a phylogenetic analysis of the bumble bee subgenus Fervidobombus. There is no significant incongruence between the three molecular data sets, and little incongruence between the DNA and morphology. Simultaneous analysis of all the data partitions resulted in a tree that w...
Bumblebees (Bombus species) are major pollinators of commercial crops and wildflowers but factors affecting their abundance, including causes of recent population declines, remain unclear. Investigating the ecology of species with expanding ranges provides a potentially powerful means of elucidating these factors. Such species may also bring novel pollination services to their new ranges. We th...
Four British bumblebee species (Bombus terrestris, Bombus hortorum, Bombus ruderatus and Bombus subterraneus) became established in New Zealand following their introduction at the turn of the last century. Of these, two remain common in the United Kingdom (B. terrestris and B. hortorum), whilst two (B. ruderatus and B. subterraneus) have undergone marked declines, the latter being declared exti...
Bumblebees are major pollinators of crops and wildflowers in northern temperate regions. Knowledge of their ecology is vital for the design of effective management and conservation strategies but key aspects remain poorly understood. Here we employed microsatellite markers to estimate and compare foraging range and nest density among four UK species: Bombus terrestris, Bombus pascuorum, Bombus ...
The neogregarine Apicystis bombi is considered a low prevalence parasite of Bombus spp. Before our work it has only once been detected in one single specimen of the Western honeybee Apis mellifera. This contribution reports the presence of A. bombi parasitizing both A. mellifera and Bombus terrestris at a site in Northwestern Argentine Patagonia (Bariloche, close to the border with Chile) and a...
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