A Warming World May Spell Bad News for Honey Bees

The following is brought to us by ABJ Extra    November 26, 2014

Researchers have found that the spread of an exotic honey bee parasite, Nosema ceranae, -now found worldwide - is linked not only to its superior competitive ability, but also to climate, according to a new study published in the journal Proceedings of the Royal Society B.

The team of researchers, including Myrsini Natsopoulou from the Martin-Luther-Universität Halle-Wittenberg, who co-led the research alongside Dr. Dino McMahon from Queen's University Belfast, believes that the parasite could become more prevalent in the UK in the future and their findings demonstrate the importance of both parasite competition and climate change in the spread of this emerging disease.

Myrsini Natsopoulou said: "Our results reveal not only that the exotic parasite is a better competitor than its original close relative, but that its widespread distribution and patterns of prevalence in nature depend on climatic conditions too".

The research compared pathogen growth in honey bees that were infected with both the exotic parasite, Nosema ceranae and its original native relative, Nosema apis.

Experiments showed that, while both parasites inhibit each other's growth, the exotic Nosema ceranae has a much greater negative impact on the native Nosema apis than vice versa. By integrating the effects of competition and climate into a simple mathematical model, the researchers were better able to predict the relative occurrence of both parasite species in nature:Nosema ceranae is common in Southern Europe but rare in Northern Europe.

Coauthor of the study, Prof. Robert Paxton of Queen's University Belfast, added: "This emerging parasite is more susceptible to cold than its original close relative, possibly reflecting its presumed origin in east Asia. In the face of rising global temperatures, our findings suggest that it will increase in prevalence and potentially lead to increased honey bee colony losses in Britain."

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Parasites, Pesticides and Pollination

Bug Squad - Happenings in the Insect World   By Kathy Keatley Garvey   10/15/13

What are the indirect effects of parasites and pesticides on pollination service?

Ecologist Sandra Gillespie, a postdoctoral researcher in the Neal Williams lab, UC Davis Department of Entomology and Nematology, will present the results of her research at a departmental seminar from 12:10 to 1 p.m., Wednesday, Oct. 16 in 122 Briggs Hall. It will be recorded for later posting on UCTV.

“Whether in natural or...

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Visit the Kathy Keatley Garvey Bug Squad blog at: http://ucanr.org/blogs/bugsquad/

Parasitized Bees Have Genes Changed, Forage Earlier, More Virus

(The following is brought to us by CATCH THE BUZZ (Kim Flottum) Bee Culture, The Magazine of American Beekeeping, published by A.I. Root Company.) 7/23/13

This study from INRA (French National Institute for Agricultural Research) investigated the effect of parasitization on honey bees living in hives at Avignon. Individual bees were infected with either the ectoparasite Varroa, which lives on the bees, or endoparasite Nosema, which invades their bodies, and reintroduced to the hive. After a few days the effect of infection on bees and their behavior was monitored.

Parasitization caused changes in the levels of active genes in the brains of infected bees. Varroa altered the activity of 455 genes, including genes involved in GABA and serotonin signaling, while Nosema affected 57. Twenty genes were common between the two infections and several of the up-regulated genes are involved in oxidative stress, neural function and foraging behavior. Parasitized bees also tended to have a higher viral infection as well, adding to their disease burden, -- even if they did not have physical symptoms.

Hydrocarbons on the cuticle of bees provide a 'family' scent allowing bees from the same hive to recognize each other. The levels of these chemicals was altered by infection with either the endo- or ecto-parasite nevertheless infected bees were treated as normal by other bees -- social interactions including antennal contact, grooming, feeding, and vibration, continued -- and they were not expelled from the hive.

Dr Cynthia McDonnell who led this study commented, "Parasitized bees tend to leave the colony earlier to perform foraging activity, which could lead to a significant depopulation of the colony. However, very few studies have analyzed the impact of parasites on bee phenotypes, e.g. brain and behavior. We found that parasitized bees were not attacked by their nestmates suggesting that they leave the hive voluntarily, perhaps in response to the changes in gene expression in their brains. This social removal and the underlying mechanism might be a general and conserved response to parasitism, given that it was observed with extremely different types of parasites."

(This ezine is also available online at http://home.ezezine.com/1636/1636-2013.07.23.11.02.archive.html)

Honey Bee Die Offs Caused by Multiple Factors Including Pesticides

Moyers & Company  By Theresa Riley  5/2/13

A federal study released today attributes the massive die-off in American honey bee colonies to a combination of factors, including pesticides, poor diet, parasites and a lack of genetic diversity. Nearly a third of honey bee colonies in the United States have been wiped out since 2006. The estimated value of crops lost if bees were no longer able to pollinate fruits and vegetables is around $15 billion.

The report comes on the heels of an announcement Monday by the European Union that they are...

Read more... http://billmoyers.com/2013/05/02/honey-bee-die-off-caused/