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Evaluation of the nutritional status of worker honey bees (Apis mellifera ligustica S., 1806) across temporal patterns through morphological analysis
Get PDFHoney bee colony losses represents a significant issue in modern apiculture. Regardless of climate, most losses occur in winter which is a particularly challenging period for A. mellifera. In fact, in order to deal with harsh winter conditions honey bees evolved a seasonal caste system with fundamental physiological processes dictated by nutrition. Whereas the overwintering of honey bees in northern regions has been well studied, much less is known regarding the seasonal dynamics of these insects in southern temperate climates. The goal of this dissertation is hence to approach this knowledge gap, especially from a nutritional point of view. Firstly, an up-to-date literature review on honey bee seasonality is presented providing necessary background information. A detailed description of summer and winter bee physiology shows how A. mellifera has adapted molecular pathways into a social system of division of labour as well as a biannual worker caste system governed by various internal and external factors. Next, the use of robust individual size measurements as possible novel markers for honey bee health and nutrition was investigated. Results of this preliminary evaluation revealed abdominal length, total body length, and head width as suitable candidate markers. These findings were then applied in the long-term monitoring of Italian bees allowing for the first description of the honey bee nutritional year-cycle in a southern temperate climate. Analysis of data according to date, climate, and flower diversity revealed two critical timepoints for honey bees: summer and winter dearth. Additionally, the noted importance of precipitation in the study area demonstrates how climate change could pose a threat to European honey bee populations in the future. These findings provide insight that could benefit ongoing research efforts and inform management or conservation strategies to improve overwintering success and prevent unnecessary colony lossesGlobal honey bee colony losses represents a significant and complex issue in modern apiculture. Regardless of climate, most losses occur in winter, which is a particularly challenging period for Apis mellifera. In fact, in order to deal with the harsh winter conditions of temperate climates of the northern hemisphere, honey bees evolved a seasonal caste system (summer Vs. winter bees) with fundamental physiological processes underlying survival dictated by nutrition. Whereas the overwintering of honey bees in northern regions has been well studied, much less is known regarding the seasonal dynamics of these social insects in southern temperate climates. Because honey bee colony losses are not restricted to cold climates, and nutrition is a key factor in overwintering success, there is a pressing need to deepen our understanding of honey bee seasonality and nutrition in southern latitudes. Furthermore, given the complex aetiology of honey bee colony losses, identification of novel markers of honey bee health and nutrition would prove beneficial in the context of ongoing research and monitoring efforts. Lastly, since a higher survival rate of local subspecies adapted to specific climatic conditions has been shown, knowledge of southern honey bee populations is of increasing interest, especially in the face of accelerated climate change the world is facing in present days.
The various publications in this dissertation add to the current knowledge of these subject areas. Firstly, an up-to-date literature review containing a centralised overview of honey bee worker dynamics, division of labour, and seasonality in temperate climates of the northern hemisphere is presented. A detailed description of the relevant physiology of summer and winter bees illustrates how A. mellifera has adapted molecular pathways into an effective social system for the division of labour as well as a bimodal, biannual worker caste system. The mechanism behind honey bee seasonality governed by a multitude of internal and external factors with varying sensitivity is described and research gaps are highlighted. Secondly, the results of the preliminary evaluation and proof of concept for the use of robust measurements of individual size (head width, thoracal width and length, abdominal width and length, and total body length) as possible markers for honey bee health and nutrition are reported. Specifically, abdominal and total body length were identified through correlation analysis as suitable candidate markers in forager bees, while head width showed promise as a marker across temporal patterns. Thirdly, the long-term monitoring of selected individual size measurements of the locally adapted A. m. ligustica allowed for the first description of the honey bee nutritional year-cycle in a southern temperate climate. Analysis of data according to sampling date, climate (temperature, precipitation, and daylength), and flower diversity, revealed two critical timepoints for honey bee nutrition: summer and winter dearth. Seasonality was in accordance with our previous findings, with a peak in nutrient storage indicating the short presence of winter bees. The noted importance of precipitation for honey bee nutrition in the study area demonstrates how climate change could pose a threat to European honey bee populations in the future. Finally, size measurements were shown to vary significantly between nurse and forager bees further illustrating the potential value of selected morphological markers.
The findings reported in this dissertation provide insight that could benefit ongoing research efforts and inform management or conservation strategies with the ultimate goal of improving overwintering success and preventing unnecessary colony losses. Present results can furthermore be used as a cornerstone for future research on honey bee nutrition and seasonality in southern temperate climates
Foraging Activity of Honey Bees (Apis mellifera L., 1758) and Exposure to Cadmium: a Review
No full textHoney bees are commonly exposed to a broad spectrum of xenobiotics, including heavy metals. Heavy metal toxicity is of concern in the context of global pollinator declines, especially since honey bees seem to be particularly susceptible to xenobiotics in general. Here we summarize current knowledge on the interplay between cadmium, one of the most toxic and mobile elements in the environment, and honey bees, the primary managed pollinator species worldwide. Overall, cadmium pollution has been shown to be ubiquitous, affecting industrial, urban and rural areas alike. Uptake of this heavy metal by plants serves as the primary route of exposure for bees (through pollen and nectar). Reported cadmium toxicity consists of lethal and sublethal effects (reduced development and growth) in both adult and larval stages, as well as various molecular responses related to detoxification and cellular antioxidant defence systems. Other effects of cadmium in honey bees include the disruption of synaptic signalling, calcium metabolism and muscle function
The Nutritional Year-Cycle of Italian Honey Bees (Apis mellifera ligustica) in a Southern Temperate Climate
Get PDFNutrition is a key aspect influencing honey bee health and overwintering. Since honey bee seasonality in southern temperate climates represents a significant research gap, this study conducted long-term monitoring of honey bees in the Mediterranean (Sassari, Italy). Specifically, individual weight, fat body, and size measurements (head, thorax, abdomen, and total body) were recorded monthly so to detect changes in the nutrient storage of worker bees during an annual cycle. Data were analysed according to sampling date, climate (temperature, precipitation, and daylength), and flower diversity and were conducted for nurse and forager bees separately. The nutritional honey bee year-cycle generally followed the nectar flow and showed two critical timepoints: summer and winter dearth. A short cessation of activities in late fall/early winter coupled with an increase in nutrient storage indicated the presence of winter bees. Precipitation was found to play an important role in honey bee nutrition in the study area through its impacts on colony demography and plants in particular illustrating how climate change could pose a threat to European honey bee populations in the future. These results provide valuable insights into the nutritional dynamics of Apis mellifera ligustica in the Mediterranean that could support management decisions to improve overwintering success and prevent unnecessary colony losses
Dorbignysuchus niatu Jouve & Muizon & Cespedes-Paz & Sossa-Soruco & Knoll 2021, SP. NOV.
No full textDORBIGNYSUCHUS NIATU SP. NOV. <p>(FIGS 13–15)</p> <p>L S I D: u r n: l s i d: z o o b a n k. o r g: a c t: 7 0 F 0 0 E 0 0 - 4C00-44E1-B9F3-C9285047388B</p> <p> <i>Etymology</i></p> <p> Latinization of the Quechua <i>ñat’u</i>, meaning short nose, in reference to the short size of the snout of the species. It is a noun in apposition.</p> <p> <i>Holotype</i></p> <p>MHNC.13500, a partial skull and mandible belonging to the same individual (Fig. 14).</p>Published as part of <i>Jouve, Stéphane, Muizon, Christian De, Cespedes-Paz, Ricardo, Sossa-Soruco, Víctor & Knoll, Stephane, 2021, The longirostrine crocodyliforms from Bolivia and their evolution through the Cretaceous-Palaeogene boundary, pp. 475-509 in Zoological Journal of the Linnean Society 192</i> on page 48
Rodeosuchus Jouve & Muizon & Cespedes-Paz & Sossa-Soruco & Knoll 2021, GEN. NOV.
No full textRODEOSUCHUS GEN. NOV. <p>LSID: urn:lsid:zoobank.org:act: 5FF9D13A-1830- 4906-AE23-D6F90DF2A125</p> <p> <i>Etymology</i></p> <p> The name refers to <i>Rodeo</i>, the name of the river that passes close to the type locality (Cementerio de Tortugas), and the Latinized Ancient Greek name Σοῦχος, <i>Soûkhos</i>, used for the Egyptian crocodile god Sobek.</p> <p> <i>Diagnosis</i></p> <p>As for the only known species.</p>Published as part of <i>Jouve, Stéphane, Muizon, Christian De, Cespedes-Paz, Ricardo, Sossa-Soruco, Víctor & Knoll, Stephane, 2021, The longirostrine crocodyliforms from Bolivia and their evolution through the Cretaceous-Palaeogene boundary, pp. 475-509 in Zoological Journal of the Linnean Society 192</i> on page 48
Dorbignysuchus Jouve & Muizon & Cespedes-Paz & Sossa-Soruco & Knoll 2021, GEN. NOV.
No full textDORBIGNYSUCHUS GEN. NOV. <p>(FIGS 13–15)</p> <p>L S I D: u r n: l s i d: z o o b a n k. o r g: a c t: 8 D F 7 0 2 5 3 - 7362-467F-961C-130026FFB248</p> <p> <i>Etymology</i></p> <p> Named in honor of French naturalist Alcide Charles Victor Marie Dessalines d’Orbigny (6 September 1802 to 30 June 1857), Professor of Palaeontology at the Paris Muséum National d’Histoire Naturelle, who explored South America, including Bolivia, during the 19 th century. The suffix - <i>suchus</i> is derived from the Ancient Greek name Σοῦχος, used for the Egyptian crocodile god Sobek.</p> <p> <i>Diagnosis</i></p> <p>As for the only known species.</p>Published as part of <i>Jouve, Stéphane, Muizon, Christian De, Cespedes-Paz, Ricardo, Sossa-Soruco, Víctor & Knoll, Stephane, 2021, The longirostrine crocodyliforms from Bolivia and their evolution through the Cretaceous-Palaeogene boundary, pp. 475-509 in Zoological Journal of the Linnean Society 192</i> on page 48
Rodeosuchus machukiru Jouve & Muizon & Cespedes-Paz & Sossa-Soruco & Knoll 2021, SP. NOV.
No full textRODEOSUCHUS MACHUKIRU SP. NOV. <p>(FIG. 5A–D)</p> <p>L S I D: u r n: l s i d: z o o b a n k. o r g: a c t: 5B A F E A 0 4- F490-4589-8AF9-F534D3D81989</p> <p> <i>Etymology</i></p> <p> From Quechua <i>machu kiru</i>, meaning large teeth, in reference to the size of the teeth observed in the species. The name is a noun in apposition.</p> <p> <i>Holotype</i></p> <p>MHNC.13829, holotype, a nearly complete skull lacking the posterior palatal surface and most of the basicranium.</p> <p> <i>Type locality</i></p> <p>Cementerio de Tortugas, a field in a place known as Molle Cancha, close to the village of Torotoro, Charcas Province, Department of Potosí, Bolivia.</p>Published as part of <i>Jouve, Stéphane, Muizon, Christian De, Cespedes-Paz, Ricardo, Sossa-Soruco, Víctor & Knoll, Stephane, 2021, The longirostrine crocodyliforms from Bolivia and their evolution through the Cretaceous-Palaeogene boundary, pp. 475-509 in Zoological Journal of the Linnean Society 192</i> on page 48
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Environmental Contamination by Dog Feces in Touristic Areas of Italy: Parasitological Aspects and Zoonotic Hazards
No full textPublic spaces are common sites of fecal contamination which is concerning considering the prevalence rates of gastrointestinal pathogens carried by pets. Multiple pet-bound parasite species capable of infecting humans have previously been reported in fecal samples collected from urban areas around the globe, including Italy. In addition, the presence of gastrointestinal parasites has recently been shown in pets from the island of Sardinia, a well-known touristic destination. For these reasons, this study aims to evaluate the level of fecal contamination of two of the most important cities on Sardinia. Furthermore, the presence of endoparasites in fecal samples collected was also investigated to assess the parasitological risks associated with such contamination. A grid approach using a geographical information system was applied, followed by transect counting and sampling. A total of 956 and 220 dog feces with an average feces count of 4.7 and 2.6 per 100 linear meters were found for Sassari and Alghero, respectively. In Sassari 15.6% (52/333) and in Alghero 6.8% (6/88) of the samples tested positive for parasitic elements. Hookworms, Strongyloides stercoralis, Toxocara sp., and Trichuris vulpis were among the parasites most identified. This study showed significant urban contamination of both Sassari and Alghero with dog feces and the parasites within them, including potentially zoonotic species. The general public as well as tourists visiting the island should be aware of the risks associated with this and appropriate measures taken
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