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Regina, Canada

Sheffield C.S.,Royal Saskatchewan Museum
ZooKeys | Year: 2013

A new species of leafcutter bee, Megachile (Megachiloides) chomskyi, is described from Texas, United States. Megachile chomskyi is one of the four known species of the oenotherae species group of Megachiloides, all members sharing the long tongue, and is most similar to M. (Megachiloides) amica Cresson. Like other members of the oenotherae species group, this species probably shows oligolecty with Onagraceae (Evening- Primrose Family). A diagnosis, full description of both sexes and a key to the species of the oenotherae species group are provided. © Cory S. Sheffield. Source


Sheffield C.S.,Royal Saskatchewan Museum | Pindar A.,York University | Packer L.,York University | Kevan P.G.,University of Guelph
Apidologie | Year: 2013

Many factors affect bee diversity and abundance, and knowledge of these is crucial for maintaining healthy bee communities. However, there are few means to fully evaluate the status of bee communities; most are based on monitoring species richness and abundance and do not consider the diverse life histories of bees. We propose that functional diversity of bee communities offers a more consistent means of evaluation and suggest that cleptoparasitic bees in particular show much promise as indicator taxa. Cleptoparasitic bees play a stabilising role within bee communities. They represent the apex of bee communities and are the first guild to respond to disturbances, are easily distinguished as such and are diverse enough to be representative of entire bee communities. The diversity and abundance of cleptoparasites in relation to all bees is indicative of the status of the total bee community, and monitoring them should form an integral part of assessing bee communities. © 2013 INRA, DIB and Springer-Verlag France. Source


Stahlhut J.K.,University of Guelph | Gibbs J.,Cornell University | Sheffield C.S.,Royal Saskatchewan Museum | Smith M.A.,University of Guelph | Packer L.,York University
Systematics and Biodiversity | Year: 2012

In a recent Perspective, Gerth et al. (2011) expressed concern over how Wolbachia (Wolbachia pipientis Hertig) infections may affect the success of DNA barcoding efforts in bees. The potential and realized effects of endosymbiont-induced selective sweeps on host mitochondrial DNA diversity have been noted repeatedly - and rightly so - in the literature for some years. However, we are equally concerned with other misconceptions, including (a) presuming that a positive Wolbachia test indicates a stable infection, (b) presuming that Wolbachia-infected hosts cannot be identified with a single-locus barcode, and (c) inferring specific Wolbachia-mtDNA interactions based only on incomplete genotyping of Wolbachia strains. We address these issues in the context of the Gerth et al. (2011) survey of Wolbachia prevalence among the German bee fauna. We also clarify some of the context-dependent strengths and limitations of DNA barcoding when it is used as a research tool by taxonomists and ecologists. © 2012 The Natural History Museum. Source


Sheffield C.S.,Royal Saskatchewan Museum | Kevan P.G.,University of Guelph | Pindar A.,York University | Packer L.,York University
Canadian Entomologist | Year: 2013

Bees are important within terrestrial ecosystems, providing pollination, which facilitates plant reproduction. Agricultural regions are large landscapes containing varying proportions of cropland, natural, and semi-natural habitats. Most bees are not restricted to any of these and move freely throughout, exploiting food and nesting resources in favourable locations. Many factors affect bee diversity, and knowledge of these is crucial for promoting healthy bee communities. The main objectives of this study were to compare diversity and guild structure of bee communities across a range of land disturbance levels within the Annapolis Valley, Nova Scotia, Canada, in habitats ranging from managed apple orchards to old fields. The two habitat extremes differed significantly; intensely managed orchards had significantly lower species richness (∼50%) than observed/estimated in old fields, but orchards with intermediate levels of adjacent natural/semi-natural habitat showed affinities to either extreme depending on the metrics used for estimating species richness. Species assemblages in orchards had lower proportions of several guilds, particularly cavity-nesters, bumble bees, and cleptoparasites, than other habitats. These guilds accounted for over 30% of bees collected in old fields but only 3-10% in orchards, increasing with habitat complexity. The use of guilds for assessing the health of bee communities is discussed. Copyright © 2013 Entomological Society of Canada. Source


News Article | June 29, 2016
Site: http://www.techtimes.com/rss/sections/earth.xml

Scientists occasionally find parts of animals trapped in solidified tree saps called amber, but when a group of researchers found a pair of bird-like wings encased inside an amber mined in Myanmar, they knew that they found something special. Canada's Royal Saskatchewan Museum curator of invertebrate paleontology Ryan McKellar explained that one of the biggest challenges researchers face with feathers in amber is that they are often small fragments or isolated feathers. Feathers do not always survive the fossilization process, and most of the information that scientists learn about prehistoric feathers were from amber fossils that often contain only single feathers, which do not provide much information about the creature they belonged to. The newly found wings, however, were different. At about 99 million years old, they are among the most pristine fossilized feathers to be found. Researchers said that this pair of tiny wings are the first Cretaceous plumage samples to be analyzed that are not isolated feathers. McKellar explained that the fossilized remains is the next best thing to holding the animal in the hand. The amber preserved every detail of the tiny wings, which makes it possible to see the traces of feathers, hair and bones and how these were arranged. The color of the feathers also survived and can still be seen. With these wings, McKellar and colleagues were able to reconstruct what the bird may have looked like when it roamed the Earth alongside dinosaurs during the Cretaceous Period. The wings belonged to members of a now-extinct group of hummingbird-size creatures known as Enantiornithes. Based on results of X-ray micro-CT analysis, the samples belong to juveniles as hinted by the bone size. "The extremely small size and osteological development of the wings, combined with their digit proportions, strongly suggests that the remains represent precocial hatchlings of enantiornithine birds," the researchers wrote in their study, which was published in the journal Nature Communications on June 28. These ancient birds have teeth and clawed wings, but they look similar to their modern-day relatives. Unlike most modern bird hatchlings, however, these ancient birds were born almost fully developed. Study researcher Xing Lida, from China University of Geosciences in Beijing, said that the fact that the birds were clambering about in the trees show they had advanced development at their age, which means that they were already ready for action when they were hatched. "These birds did not hang about in the nest waiting to be fed, but set off looking for food, and sadly died perhaps because of their small size and lack of experience," Xing Lida said. "Isolated feathers in other amber samples show that adult birds might have avoided the sticky sap, or pulled themselves free." © 2016 Tech Times, All rights reserved. Do not reproduce without permission.

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