BEE-L Archives

Informed Discussion of Beekeeping Issues and Bee Biology

BEE-L@COMMUNITY.LSOFT.COM

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Peter L. Borst" <[log in to unmask]>
Reply To:
Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Wed, 25 Jul 2007 08:00:52 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (66 lines)
More on Bee Sex:

Why do queen honeybees mate with dozens of males? Does their extreme
promiscuity, perhaps, serve a purpose?

Colonies of promiscuous queens tend to be far more successful in such chores
and in surviving their first winter than colonies produced by monogamous
queens, report Cornell researchers Tom Seeley and Heather Mattila in Science
magazine.

An answer to this age-old mystery is proposed in the July 20 issue of
Science magazine by Cornell scientists: Promiscuous queens, they suggest,
produce genetically diverse colonies that are far more productive and hardy
than genetically uniform colonies produced by monogamous queens.

"An intriguing trait of honeybee species worldwide is that each honeybee
queen mates with an extraordinarily high number of males," said Heather R.
Mattila, a Cornell postdoctoral fellow in neurobiology and behavior and
co-author of the article with Thomas D. Seeley, Cornell professor of
neurobiology and behavior.

In every honeybee species, say the researchers, queens mate with multiple
males. The European honeybee -- the common species in North America -- mates
with from six to 20 mates on average, for example, while the giant honeybee
in Asia has a reported record of 102 mates.

To study the reasons for honeybees' promiscuity, the Cornell biologists
inseminated 12 queens with sperm from 15 drones (a different set for each)
and nine additional queens with sperm from a single drone (but a different
one in each case). They then prompted the hives to swarm in early June to
form new colonies.

"After only two weeks of building new nests, the genetically diverse
colonies constructed 30 percent more comb, stored 39 percent more food and
maintained foraging levels that were 27 to 78 percent higher than
genetically uniform colonies," said Mattila.

By the end of the summer, the genetically diverse colonies had five times
more bees, eight times more reproductive males and heavier average body
weights, mostly because of larger amounts of stored food.

By winter's end, 25 percent of the genetically diverse colonies survived to
their one-year anniversary (only about 20 percent of new honeybee colonies
make it that long in upstate New York). But all of the genetically uniform
hives starved to death.

"These differences are noteworthy considering colonies had similarly sized
worker populations when they were first formed," said Mattila. "Undoubtedly,
our results reveal enormous benefits of genetic diversity for the
productivity of honeybee colonies."

For example, the researchers found that bees in the genetically diverse
colonies used sophisticated mechanisms for communication, including waggle
dancing, more often than bees in genetically uniform colonies to discover
food sources and direct nest mates to food. Because there was more
information available among nest mates about food discoveries, the diverse
colonies gained far more weight than did genetically uniform colonies.

-- 
http://www.news.cornell.edu/stories/July07/beesPromiscuity.sl.html

******************************************************
* Full guidelines for BEE-L posting are at:          *
* http://www.honeybeeworld.com/bee-l/guidelines.htm  *
******************************************************

ATOM RSS1 RSS2