10,281 research outputs found
Managed honey bee colony losses in Canada, China, Europe, Israel and Turkey, for the winters of 2008-9 and 1009-10
No full textIn 2008 the COLOSS network was formed by honey bee experts from Europe and the USA. The primary objectives set by this scientific network were to explain and to prevent large scale losses of honey bee (Apis mellifera) colonies. In June 2008 COLOSS obtained four years support from the European Union from COST and was designated as COST Action FA0803 – COLOSS (Prevention of honey bee COlony LOSSes). To enable the comparison of loss data between participating countries, a standardized COLOSS questionnaire was developed. Using this questionnaire information on honey bee losses has been collected over two years. Survey data presented in this study were gathered in 2009 from 12 countries and in 2010 from 24 countries. Mean honey bee losses in Europe varied widely, between 7-22% over the 2008-9 winter and between 7-30% over the 2009-10 winter. An important finding is that for all countries which participated in 2008-9, winter losses in 2009-10 were found to be substantially higher. In 2009-10, winter losses in South East Europe were at such a low level that the factors causing the losses in other parts of Europe were absent, or at a level which did not affect colony survival. The five provinces of China, which were included in 2009-10, showed very low mean (4%) A. mellifera winter losses. In six Canadian provinces, mean winter losses in 2010 varied between 16-25%, losses in Nova Scotia (40%) being exceptionally high. In most countries and in both monitoring years, hobbyist beekeepers (1-50 colonies) experienced higher losses than practitioners with intermediate beekeeping operations (51-500 colonies). This relationship between scale of beekeeping and extent of losses effect was also observed in 2009-10, but was less pronounced. In Belgium, Italy, the Netherlands and Poland, 2008-9 mean winter losses for beekeepers who reported ‘disappeared’ colonies were significantly higher compared to mean winter losses of beekeepers who did not report ‘disappeared’ colonies. Mean 2008-9 winter losses for those beekeepers in the Netherlands who reported symptoms similar to “Colony Collapse Disorder” (CCD), namely: 1. no dead bees in or surrounding the hive while; 2. capped brood was present, were significantly higher than mean winter losses for those beekeepers who reported ‘disappeared’ colonies without the presence of capped brood in the empty hives. In the winter of 2009-10 in the majority of participating countries, beekeepers who reported ‘disappeared’ colonies experienced higher winter losses compared with beekeepers, who experienced winter losses but did not report ‘disappeared’ colonies
The antibacterial activity of honey: 2. Variation in the potency of the antibacterial activity
No full textHoney is gaining acceptance by the medical profession for use as an antibacterial agent for the treatment of ulcers and bed sores, and other surface infections resulting from burns and wounds. In many cases it is being used with success on infections not responding to standard antibiotic and antiseptic therapy. Its effectiveness in rapidly clearing up infection and promoting healing is not surprising in light of the large number of research findings on its antibacterial activity, covered in Part 1 of this review
Molecular and phylogenetic characterization of honey bee viruses, Nosema microsporidia, protozoan parasites, and parasitic mites in China
No full textChina has the largest number of managed honey bee colonies, which produce the highest quantity of honey and royal jelly in the world; however, the presence of honey bee pathogens and parasites has never been rigorously identified in Chinese apiaries. We thus conducted a molecular survey of honey bee RNA viruses, Nosema microsporidia, protozoan parasites, and tracheal mites associated with nonnative Apis mellifera ligustica and native Apis cerana cerana colonies in China. We found the presence of black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), and sacbrood virus (SBV), but not that of acute bee paralysis virus (ABPV) or Kashmir bee virus (KBV). DWV was the most prevalent in the tested samples. Phylogenies of Chinese viral isolates demonstrated that genetically heterogeneous populations of BQCV, CBPV, DWV, and A. cerana-infecting SBV, and relatively homogenous populations of IAPV and A. meliifera-infecting new strain of SBV with single origins, are spread in Chinese apiaries. Similar to previous observations in many countries, Nosema ceranae, but not Nosema apis, was prevalent in the tested samples. Crithidia mellificae, but not Apicystis bombi was found in five samples, including one A. c. cerana colony, demonstrating that C. mellificae is capable of infecting multiple honey bee species. Based on kinetoplast-encoded cytochrome b sequences, the C. mellificae isolate from A. c. cerana represents a novel haplotype with 19 nucleotide differences from the Chinese and Japanese isolates from A. m. ligustica. This suggests that A. c. cerana is the native host for this specific haplotype. The tracheal mite, Acarapis woodi, was detected in one A. m. ligustica colony. Our results demonstrate that honey bee RNA viruses, N. ceranae, C. mellificae, and tracheal mites are present in Chinese apiaries, and some might be originated from native Asian honey bees
Floral resource diversity drives bee community diversity in prairie restorations along an agricultural landscape gradient
No full textThere are four files for this analysis. The Species Data includes information on what bees were collected at which sites. The site by round file contains the site information in a site by round interaction format for recreating the local diversity analysis and contains floral resource richness values for each unique site by round combination. The site data sheet is simply the site information with floral resource richness pooled over the entire sampling season.These data are for recreating the analysis conducted for "Floral resource diversity drives bee community diversity in prairie restorations along an agricultural landscape gradient" in Journal of Applied EcologyMinnesota Environment and Natural Resources Trust Fund (M.L. 2016, Chp. 186, Sec. 2, Subd. 03a)Lane, Ian G; Herron-Sweet, Christina R; Portman, Zachary M; Cariveau, Daniel P. (2020). Floral resource diversity drives bee community diversity in prairie restorations along an agricultural landscape gradient. Retrieved from the University Digital Conservancy, https://doi.org/10.13020/23ar-k510
INFLUENCE OF TEMPERATURE ON HONEY BEE SUSCEPTIBILITY TO PESTICIDES
No full textEPPO (2010 EPPO Bulletin 40(3): 313-319) and OECD (1998) are the European official guidelines that describe how to conduct trials for the evaluation of side-effects of plant protection products on honey bees. According to these guidelines, acute oral toxicity tests on adult honey bees should be carried out at 25±2°C.
In nature, adult forager bees may be exposed to a wide range of temperatures: from about 15°C (when foragers fly in spring) to 35°C (brood nest temperature) or even more (outside in hot climates). Since forager bees may also be exposed to pesticides, the purpose of this work was to investigate the influence of temperature on the susceptibility of forager bees to these substances.
Exiting forager bees from healthy and queen-right colonies were collected. Subsequently, acute oral LD50 tests were carried out at three different temperatures: 25±0.5, 30±0.5 and 35±0.5°C. Three active ingredients (fipronil, clothianidin and thiamethoxam) were separately tested. Following the European official guidelines (EPPO and OECD), five different doses of each a.i. and a control were provided via bulk administration in 10μL 50% w/w of sucrose solution per bee. Three or four replicates in different seasons were carried out. Mortality at 24 hours was assessed and LD50 with confidence intervals were calculated (Probit analysis, Polo LeOra software).
The results show that the LD50 value depends on the test temperature. This relationship was confirmed statistically in all the replicates of fipronil and thiamethoxam and in 2 of 4 replicates of clothianidin. Furthermore, different substance groups have different LD50 trends in relation to the temperature. In fact, with the increase of the temperature A) the toxicity of fipronil (phenylpyrazole) increases, while B) the toxicities of clothianidin and thiamethoxam (neonicotinoids) decrease.
To conclude, the toxicity of pesticides to forager bees is influenced by the temperature which the bees are exposed to. Interestingly, the strength and sign of this correlation depend on the characteristics of the a.i./substance group.
The European official guidelines used in the pesticide registration process (EPPO, OECD) allow to perform toxicity tests at a single temperature within 23-27°C: this wide range gives the interested parts the opportunity to carry out the tests at the temperature that will cause the preferred effect. Thus, to carefully evaluate the effects of an a.i., toxicity tests should be carried out at least at two different temperatures distant by 10°C (e.g. 25°C and 35°C). Otherwise, the hazard which the bees are exposed to could be underestimated
Reproduction of Varroa destructor in sealed worker bee brood cells of Apis mellifera carnica and Apis mellifera syriaca in Jordan
No full textThe reproduction of the honey bee mite, Varroa destructor in sealed worker bee brood cells represents an important factor for the population development of this parasite in honey bee colonies. In this study, the relative infestation levels of worker brood cells, mite fertility (mites that lay at least one egg) and reproductive rate (number of viable adult daughters per mother mite) of Varroa mite in worker brood cells of Apis m. carnica and Apis m. syriaca were compared in fall 2003 and summer 2004 at two locations in Jordan. The relative infestation levels in sealed worker brood cells ranged from 23 – 32 % in fall and 19 – 28 % in summer. The average fertility of Varroa mite ranged between 90 - 98% in colonies of A. m. carnica and between 88 - 96 % in A. m. syriaca with minor differences between colonies and locations. The number of total progeny of fertile mites in worker brood cells was 4.0 in both bee races. The reproductive rate was high with 2.7 and 2.6 in both honey bee races. The post-capping period of the worker brood cells differs only slightly between both bee races and between locations (284.4 h on average, n = 4,000). Our data reveal surprisingly high mite fertility and reproductive rates in both honeybee races under Mediterranean conditions of Jordan. The possible physiological background of Varroa reproduction and the impact of mite fertility on the development of Varroa tolerance are discussed
CITTADINANZA ATTIVA, PARTECIPAZIONE POLITICA E IDENTITÀ EUROPEA. DISCORSI E PRATICHE IN ITALIA E REGNO UNITO
No full textLo scopo di questo articolo è quello di analizzare le tendenze
concettualizzate intorno al tema della cittadinanza in Italia e nel Regno Unito.
L’intento è di mettere in luce i significati associati alla pratica di cittadinanza attiva
in entrambi i paesi: nel caso italiano vengono confrontati diversi stili (top-down e
bottom-up) di sviluppo della cittadinanza attiva che sono stati promossi sia a livello
istituzionale sia a livello di società civile. Nel caso britannico viene fatta invece una
panoramica della riforma della cittadinanza promossa sotto i governi della Nuova
Destra di Margareth Thatcher e successivamente del New Labour di Blair dopo le
elezioni nel 1997. Nella seconda parte del lavoro vengono presentati i risultati
emersi da una serie di interviste condotte con attivisti delle ONG, con lo scopo di
fornire spunti riflessivi sui concetti di partecipazione politica e di europeizzazione
Intrauterine growth restriction, defined by an elevated brain-to-liver weight ratio, affects faecal microbiota composition and, to a lesser extent, plasma metabolome profile at different ages in pigs
No full textBackground Intrauterine growth restriction (IUGR) affects up to 30% of piglets in a litter. Piglets exposed to IUGR prioritize brain development during gestation, resulting in a higher brain-to-liver weight ratio (BrW/LW) at birth. IUGR is associated with increased mortality, compromised metabolism, and gut health. However, the dynamic metabolic and microbial shifts in IUGR-affected pigs remain poorly understood. This study aimed to investigate the longitudinal effects of IUGR, defined by a high BrW/LW, on the composition of faecal microbiota and plasma metabolome in pigs from birth to slaughter. One day (+/- 1) after birth, computed tomography was performed on each piglet to assess their brain and liver weights. The pigs with the highest (IUGR = 12) and the lowest (NORM = 12) BrW/LW were selected to collect faeces and blood during lactation (day 16 +/- 0.6, T1) and at the end of the starter period (day 63 +/- 8.6, T2) and faeces at the beginning (day 119 +/- 11.4, T3) and end of the finisher period (day 162 +/- 14.3, T4). Results Faecal microbial Alpha diversity remained unaffected by IUGR across all time points. However, the Beta diversity was influenced by IUGR at T1 (P = 0.002), T2 (P = 0.08), and T3 (P = 0.03). Specifically, IUGR pigs displayed higher abundances of Clostridium sensu stricto 1 (P-adj = 0.03) and Romboutsia (P-adj = 0.05) at T1, Prevotellaceae NK3B31 group (P-adj = 0.02), Rikenellaceae RC9 gut group (P-adj = 0.03), and Alloprevotella (P-adj = 0.03) at T2, and p-2534-18B5 gut group (P-adj = 0.03) at T3. Conversely, the NORM group exhibited higher abundances of Ruminococcus (P-adj = 0.01) at T1, HT002 (P-adj = 0.05) at T2, and Prevotella_9 (P-adj < 0.001) at T3. None of the plasma metabolites showed significant differences at T1 between the IUGR and NORM pigs. However, at T2, asparagine was lower in the IUGR compared to the NORM group (P < 0.05). Conclusions These findings show that growth restriction in the uterus has a significant impact on the faecal microbiota composition in pigs, from birth to the beginning of the finisher period, but minimally affects the plasma metabolome profile
Intrauterine growth restriction defined by increased brain-to-liver weight ratio affects postnatal growth and protein efficiency in pigs
No full textIntrauterine growth restriction (IUGR) refers to impaired foetal growth during gestation, resulting in permanent stunting effects on the offspring. This study aimed to investigate the effects of IUGR on growth performance, body composition, blood metabolites, and meat quality of pigs from birth (n = 268) to slaughter (n = 93). IUGR piglets have prioritised brain development as a foetal adaptive reaction to placental insufficiency. This survival mechanism results in a higher brain-to-liver weight ratio (BrW/LW). One day (±1) after birth, computed tomography (CT) was performed on each piglet to assess their brain and liver weights. A threshold value of 0.78 (mean + SD) was chosen to divide the piglets into two categories – NORM (BrW/LW < 0.78) and IUGR (BrW/LW > 0.78). Moreover, each piglet was classified as either normal (score 1), mild IUGR (score 2), or severe IUGR (score 3) based on the head morphology. BW was recorded weekly, and average daily gain (ADG) was calculated for lactation, starter, grower, and finisher periods. Body composition was assessed after weaning (29.6 ± 0.7 d), at 20 kg (64 ± 7.2 d), 100 kg (165 ± 12.3 d), and on the carcasses using Dual-energy X-ray absorptiometry (DXA). Content and deposition rates of single nutrients, as well as energy and CP efficiency, were measured at 20 and 100 kg. Feed intake was recorded from 20 kg to slaughter. Meat quality was assessed on the carcasses. A total of 70% of the piglets assigned a score of 3 were NORM according to their BrW/LW. The IUGR category showed a lower ADG in the lactation (P < 0.01), starter (P = 0.07), and grower phases (P < 0.05) and a reduced CP efficiency in the grower–finisher period (P < 0.01) compared to the NORM group. IUGR pigs had a lower gain-to-feed ratio in the finisher period (P = 0.01) despite similar average daily feed intake, and they required more days (P < 0.01) to reach the slaughter weight. Additionally, their meat was darker (P = 0.01) than that of NORM pigs. The BrW/LW was inversely proportional to the ADG from birth to slaughter and negatively correlated with the CP deposition rate and efficiency in the grower–finisher period (P < 0.01). Furthermore, the higher the BrW/LW, the longer it took the pigs to reach the slaughter weight (P < 0.01). In conclusion, the identification of IUGR piglets based on the head morphology does not always agree with an increased BrW/LW. IUGR affects growth performance from birth to slaughter, CP efficiency in the grower–finisher period and meat quality
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