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:
randy oliver <[log in to unmask]>
Reply To:
Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Fri, 10 Apr 2009 08:36:54 -0700
Content-Type:
text/plain
Parts/Attachments:
text/plain (39 lines)
>
>  Randy, for whom I have the utmost respect, suggested that bees de-toxify
> imidacloprid.


Thanks, Gavin, but to be clear, my statement was based upon the fact that
there are other insects which have developed resistance to imidacloprid,
likely involving the P450 enzymes (Feyereisen, R. 2005. Insect cytochrome
P450s, pp. 1-77. In Biochemistry and molecular biology. Elsevier Pergamon,
Oxford, United Kingdom).

I'm unsure as to the degree that honey bees may be able to detoxify the
product.  However, a low dose of imidacloprid (a nicotine analog) appears to
function in insects, including bees, much as nicotine does in humans--it
acts as a "stimulant."  Higher doses cause excessive muscle tremors.

The analogy may be apt, since the toxicity of a poison is all about the
amount of dose.  Many of us "poison" ourselves with sublethal doses of
alkaloids (natural plant toxins) every day.

Tobacco smokers, who crave nicotine for  alertness (or a higher dose for
relaxation), dose themselves with a couple of mg of nicotine per
cigarette--about 1/25th the lethal dose (LD50 <1 ppm).

Ninety percent of adults in North America intentionally dose themselves each
day with the alkaloid caffeine.  Two cups of coffee is about 1/40th the
lethal dose (that's about the level of toxicity that I personally enjoy)
(LD50 for humans about 175 ppm).

So the question to ask about imidacloprid is, are sublethal doses toxic, or
do they just give the bees a "buzz"?

Randy Oliver

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned 
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

ATOM RSS1 RSS2