Experts urged to ratify Minamata Convention to phase out mercury-added products পারদযুক্ত পণ্যের ব্যবহার বন্ধে মিনামাতা কনভেনশন অনুমোদনের আহ্বান সেন্টমার্টিন সৈকতে প্লাস্টিকের আগ্রাসন 72 birds die eating pesticide-treated masakalai Educate girls to save the planet শিশুর সর্দি-কাশি সারানোর ঘরোয়া উপায় 50 Books All Kids Should Read Before They’re 12 24 thousand under 5 children die of pneumonia in Bangladesh annually গ্রিনহাউস গ্যাস কমানোর লক্ষ্যে নানা উদ্যোগ Maldives: Eco-friendly product export destination for Bangladesh

Larvae Parasite May Contribute to Declining Honey Bee Colonies


Biologists at UC San Diego have discovered that a tiny single-celled parasite may have a greater-than expected impact on honey bee colonies, which have been undergoing mysterious declines worldwide for the past decade.

In this week’s issue of the journal PLOS ONE, the scientists report that a microsporidian calledNosema ceranae, which has been known to infect adult Asiatic and European honey bees, can also infect honeybee larvae. They also discovered that honey bee larvae infected with the microsporidian have reduced lifespans as adults.

Since 2006, beekeepers in North America and Europe have lost about one-third of their managed bee colonies each year due to “colony collapse disorder.” While the exact cause is unknown, scientists have speculated that pesticides, pathogens, mites and certain beekeeping practices have all contributed to this decline. Nosema ceranae, a kind of fungal pathogen spread by spores, is also implicated in colony collapse because it reduces colony health and is widespread.

“Previous research suggested that Nosema ceranaecould not infect honey bee larvae,” said James Nieh, a professor of biology at UC San Diego who headed the research effort with graduate student Daren Eiri, the first author of the study. “But this was largely based upon indirect evidence: spore counts in newly emerged adult bees, which typically have low spore counts.”

Because Eiri and his co-authors conducted their experiments with larvae exposed to spores and reared in the laboratory, they said the extent of larval infection needs to be studied further using field bee colonies to determine the true impact of larval infection on colony health. Nieh noted that a study conducted recently by other scientists detected low levels of Nosema DNA in honey bee larvae, suggesting that larval infection can occur in field colonies.

“However, no study had directly investigated whether larvae could become infected with Nosema ceranae,” said Eiri. “Our study provides a direction to continue investigating this question outside the lab and in the field using entire colonies

The UC San Diego discovery may also clarify a mystery. “One puzzling aspect of Nosema ceranae infection is that infection in adult bees usually decreases after medication is given by beekeepers to a colony, but can later resurge,” Nieh said. “Some of this resurgent infection could be due to transmission between bee colonies or to adult bees that have a low, but resistant level of infection.”

Collected:  http://www.enn.com/

Posted by on May 28 2015. Filed under News at Now. You can follow any responses to this entry through the RSS 2.0. You can leave a response or trackback to this entry

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