National Wildlife Week in Canada was from 6-12 April and this
year’s theme was pollinators. Hot on its heels was National Pollinator Week in Washington D.C.
from 22-28 June. I am pleased to see an upkeep of the pollinator profile.
This is hardly surprising given the importance of these industrious workers.
Their increasing decline makes profile lifters such as these of the utmost
importance.
Birds, bees, bats, moths, butterflies, wasps, flies,
beetles, midges, thrips and ants are all pollinators. Would you believe that 40
of Haagen-Dazs’ ice cream flavours depend on pollinators (Hulka and Van
Arsdall, unda)? In Canada’s online magazine, EnviroZine, we are informed of another
fascinating fact; ‘one in every three bites of food we eat – from fruits,
berries, vegetables, nuts and seeds - is the result of pollination’. The
information to follow in the article ‘Celebrate Pollinators This Spring’, is
therefore even more worrying: ‘worldwide declines in pollinator populations’. Pollinator decline not only has an affect on
our food supply, but also complementary and alternative medicine (Cooper,
2007).
One reason for this decline has been attributed to the use
of insecticides and herbicides, which affect the pollinators themselves, their
food sources and habitats. Interestingly, we are told in the EnviroZine article,
that worldwide attention to pollinator conservation is in part thanks to
Canadian blueberry growers. DDT was used for the control of spruce budworm in
the forestry industry, but was replaced by fenitrothion in 1969. Unfortunately,
this insecticide killed off the pollinators and caused blueberry production in New Brunswick, parts of Quebec
and Ontario,
to enter a decline. The forestry industry was taken to court by the blueberry
growers, resulting in a change in forest spray policies.
Diseases and parasites are also contributing factors to
pollinator decline. Maladies such as these are well-documented for honeybees,
given their importance to apiculture. Parasites of the Western honeybee, Apis
mellifera, include the parasitic mite, Varroa destructor; and the
microsporidia, Nosema apis and Nosema ceranae. V. destructor is an ectoparasitic mite of a broad range of honey bees
and attacks all lifecycle stages (ISSG, 2005). For more information on varroa
mite, see CABI’s up and coming Invasive Species Compendium. N. apis and N.
ceranae cause nosemosis in honeybees, where the parasitic protozoa invade and
destroy cells in a bee’s gut. For more information click here.
Parasites and
diseases have been implicated as possible causal agents of colony collapse
disorder (CCD), a phenomenon that has caused 50-90% loss of honeybee colonies
in USA beekeeping operations (Cox-Foster et al., 2007). CCD, also know as disappearing
disease (Bonmatin et al., 2007), is when colonies suffer a rapid decline of
adult bees (Glinski and Kostro, 2007) – literally the colony is abandoned and
the bees are never found (Lean and Shawcross, 2007).
Other possible
culprits of CCD include: contamination of pollen and nectar by insecticides
such as imidacloprid and fipronil (Bonmatin et al., 2007); Israeli acute paralysis
virus (Cox-Foster et al., 2007); a fungus, bacterium, virus, toxin or ‘other
stresses’ (Osborne, 2007); genetically modified crops, lack of genetic
diversity and lineage of bees, immunosuppression (Glinski and Kostro, 2007);
changed cultural practices, cool brood (Oldroyd, 2007); hive beetles
(Vanengelsdorp et al., 2007); lack of food and electromagnetic radiation
(Kievits, 2007). Eastbourne certainly made efforts to look after it’s local bee
population last year when permission to erect a mobile telephone mast was
rejected, after fears that radiation may be causing bee decline (Lean and Shawcross, 2007). It
would appear that no single factor is responsible for CCD or honeybee decline
in general (Frazier et al., 2008).
Land development leading to habitat loss and landscape
fragmentation, plays a part in declining numbers of pollinators. Availability
of food resources and nesting sites are reduced. Intensive farming has led to
homogeny in the landscape and loss of wildflowers, but while this change has
affected most bumblebee species, for example, it has not affected them all
(Dicks, 2004).
The length of bumblebee tongues has been offered as an
explanation for decreasing numbers, because almost all the bumblebee species in
decline have long tongues and like flowers with long tubes of petals (clover,
vetch, knapweed, thistle), found in traditional hay meadows – also in decline.
The key here is ‘almost all’, for there are those species that do not fit this
pattern and lead us to question other factors of bumblebee life history. Little
is known about bumblebee ecology and key questions, which would help in a bee
conservation effort, remain unanswered (Dicks, 2004).
To counteract plummeting numbers, perhaps we should follow the
City of Guelph’s
lead by developing unwanted areas into havens for pollinators. It is hoped that
the world’s first pollinator park in Canada will be positioned on a 40 hectare
landfill site, containing forbs, grasses, asters, daisies, and habitat varying
from dead wood to sandy soil to rocky piles (Harries, unda).
Closer to home, its easy to encourage pollinators by leaving
an area of your garden/allotment to go wild and remain pesticide free. This
will encourage habitat diversity and corridors for pollinator movement and survival.
If you want to see the ‘big six’ * (British Isle bumblebees
that is), Lynn Dicks (2004) points us in the direction of the following
bumblebee-friendly areas: Salisbury Plain; The Somerset and Gwent Levels; The
Essex and Kent Thames corridor; The Outer Hebrides; and Castlemartin,
Pembrokeshire.
*The ‘big
six’ British Isle bumblebees are: the common carder bee (Bombus pascuorum); the
red-tailed bumblebee (Bombus lapidarius); the buff-tailed bumblebee (Bombus
terrestris); the white-tailed bumblebee (Bombus lucorum); the early bumblebee
(Bombus pratorum); and the garden bumblebee (Bombus hortorum) (Dicks, 2004).
References
Bonmatin JM, Marchand PA, Cotte JF, Aajoud A, Casabianca H, Goutailler G, Courtiade M, 2007. Bees and systematic insecticides (imidacloprid, fipronil) in pollen: subnano-quantification by HPLC/MS/MS and GC/MS. Environmental fate and ecological effects of pesticides, 827-834.
Cooper EL, 2007. Colony collapse disorder may affect complementary and alternative medicine. Evidence-based Complementary and Alternative Medicine 4 (3), 275-277.
Cox-Foster et al., 2007 A metagenomic survey of microbes in honey bee colony collapse disorder. Science Washington 318 (5848), 283-286.
Frazier M, Mullin C, Frazier J, Ashcraft, S, 2008. What have pesticides got to do with it? American Bee Journal, 521-523.
Glinski Z, Kostro K, 2007. Colony collapse disorder – a new threatening disease of honey bees. Zycie Weterynaryjne 82 (8), 651-653.
Harries K, unda. A Place for Pollinators. Ontario Nature. http://www.ontarionature.org/onnature/earthwatch.html#1
Hulka J, Van Arsdall T, unda. National Pollinator Week, June 22-28, 2008. Second Annual Campaign to protect Bees and All Pollinators. http://www.pollinator.org/Resources/PressRelease.pdf
Lean G, Shawcross H, 2007. Are mobile phones wiping out our bees? http://www.independent.co.uk/environment/nature/are-mobile-phones-wiping-out-our-bees-444768.html
Osborne WD, 2007. Mysterious honeybee deaths leave sting on agriculture. FDA Veterinarian 22 (3), 9-11.
Vanengelsdorp D, Underwood R, Caron D, Hayes J Jr, 2007. An estimate of managed colony losses in the winter of 2006-2007: a report commissioned by the Apiary Inspectors of America. American Bee Journal 147 (7), 599-603.
Comments
In the last 20 years I have created and grown my present garden here in the UK to both please me and provide a habitat for wildlife. To me a garden without visits from a minimum of birds, bees and other insects is a sterile place.
In 2007 I noticed a decline in the number of bees but thankfully there has been a slight improvement in 2008.
Sadly 2008 has been the year when the butterfly visitors have been very few, in fact some of my old favourites have not been seen.
I can but hope this is a blip but I do fear the worst.
In the last 20 years I have created and grown my present garden here in the UK to both please me and provide a habitat for wildlife. To me a garden without visits from a minimum of birds, bees and other insects is a sterile place.
In 2007 I noticed a decline in the number of bees but thankfully there has been a slight improvement in 2008.
Sadly 2008 has been the year when the butterfly visitors have been very few, in fact some of my old favourites have not been seen.
I can but hope this is a blip but I do fear the worst.
Posted by: Rodger (My Garden is My Space) Cresswell | September 03, 2008 at 08:07 PM