permaculture

["Lawrence F. London, Jr." <lflj@intrex.net>]

-------- Original Message --------
Subject: [SANET-MG] To Bee Organic or not to Bee
Date: Wed, 11 Jun 2008 11:11:15 -0400
From: jcummins <jcummins@UWO.CA>
To: SANET-MG@LISTS.IFAS.UFL.EDU

http://www.i-sis.org.uk/toBeeOrganicOrNotToBee.php
To Bee Organic or not to Bee
Prof. Joe Cummins explains why bees are especially susceptible to
pesticides

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Worsening epidemic of Colony Collapse
Colony Collapse Disorder (CCD), a growing scourge of honeybees has
struck again this year. The United Sates Department of Agriculture
(USDA) reported a 36 percent loss of colonies in managed hives over
the winter, up 13.5 percent from the previous year [1]. USDA has yet
to identify a single pathogen responsible for the disease, and has
finally begun to study the interaction between pesticides and viruses
or varroa mites as possible causes [2].

CCD is characterised by the complete absence of adult bees in the
colonies with little build-up of dead bees in or around the colonies,
but capped brood and food stores of both honey and bee bread are
present, and are not immediately robbed by other bees. Attacks by hive
pests such as wax moth and small hive beetle, if any, are noticeably
delayed.

In a colony undergoing collapse, the workforce is insufficient to
maintain the brood, and seems to be made up mostly of young adult
bees. The queen bee is present, but the cluster is reluctant to
consume provided feed such as sugar syrup and protein supplement [3].

The Institute of Science in Society has reviewed the evidence on the
impact of pesticides and the synergistic interaction between
pesticides (including Bt biopesticides now widely incorporated into
genetically modified (GM) crops) and pathogens such as the fungal
parasites [4-6] (Requiem for the Honeybee, Mystery of Disappearing
Honeybees, SiS 34; Parasitic Fungi and Pesticides Act Synergistically
to Kill Honeybees? SiS 35). That evidence was the basis for question
to the European parliament urging immediate bans on the pesticides
such as the neonicotinoid insecticides as well as GM crops containing
Bt biopesticides [7] (Emergency Motion on Protecting the Honeybee, SiS
35).

In 2008, the German government took the extraordinary step of banning
neonicotinoid pesticides (see Emergency Pesticide Ban for Saving the
Honeybee, SiS 39).

Genetics of the honeybee
The honeybee genome has been sequenced, and while rich in genes for
behaviour and learning relative to other insects, it is deficient in
genes for immunity and the ability to detoxify toxic chemicals such as
the pesticides [8]. The genes families involved in insecticide
resistance in other insects are completely lacking. These shortfalls
contribute to the sensitivity of bees to insecticides [9]. Bees have
been found to have immune systems comparable to insects such as flies
and mosquitoes, but with about one third less genes devoted to
immunity than other insects. Insects immunity involves inducible
synthesis of anti-microbial peptides and constitutive
melanisation-encapsulation response to pathogens  The reduced immune
flexibility of the honeybee may be compensated by social activity such
as hive cleaning [10].  When bees are challenged by a bacterial
pathogen, genes in the head of the bee are differentially expressed,
and show neuroimmune-behaviour interactions similar to those of
vertebrates [11].  A dysfunction in both its immune response and
behaviour triggered by exposure to pesticides could easily result in CCD.

The genetics of honey bees is now actively investigated. The male
honeybee has 24 chromosomes (linkage groups) and mapping of the
numerous genes has been achieved. Males are normally haploid, but
diploid males  are observed at low frequency. Worker bees and queens
are diploid.  One queen bee provides over 2 000 eggs per day;
unfertilized eggs become males while fertilized eggs become workers
[12]. Bee breeding has had some success, but complicated by the
breeding habit of the queen, which copulates while flying to avoid
inbreeding depression.  The problem of inbreeding in honeybees has
been studied for over fifty years, and before that, beekeepers have
recognized the problem for centuries. The population genetics of
inbreeding and homozygosis (too many genes existing as identical
pairs) was worked out in 1950 by James Crow and William Roberts in
[13]. Heterosis (hybrid vigour) in the honeybee was described in 1955
by Gladstone Gale Jr. and John Gower [14]. There has been no evidence
that inbreeding contributed to CCD because the experienced beekeepers
recognize the problem and overcome it by providing for out-breeding.
However, it is clear that the toll of CCD may result in obligatory
inbreeding due to shrinkage of the bee population, and that will
accelerate the demise of the honeybee.

To bee organic
Organic farms are proving to be sanctuaries for the honeybee from the
ravages of CCD. The honeybees are exquisite social animals perfectly
adapted for pollination and honey making, but far too delicate to
withstand the onslaught of systemic pesticides and GM crops.
Regulators are slow to control the environmental insults to the
honeybees and unprepared to act on the precautionary principle. Saving
the honeybee may be among the most compelling reasons to shift
comprehensively to organic agriculture [15] (Saving the Honeybee
Through Organic Farming, SiS 38).