The Environment
Honeybees are dying all over the world. In America, for
instance, one in three hives was left lifeless at the beginning
of 2008. Two possible reasons behind this phenomenon are
evaluated in this work.
Since winter 2006 there have been massive disappearance of bees registered
all over the world, which resulted in the phenomenon called colony collapse
disorder (CCD). This incident states the condition when the bees are unable to
return to the hive because of unusual circumstances. The U.S. Department of
Agriculture (USDA) states that the contribution of honey bees in the production of
food crops in the world is 153 billion Euros, which stands for 9.5% of all food
consumed by population worldwide (Johnson, 2010, p.i), as a result CCD caused
economic damage that was estimated at billions of dollars. The bees are the only
insects in the world, which are indirectly involved in maintaining the biological
diversity of flora and fauna, production of natural goods and the pollination of
animal feed. There are many possible factors, which may lead to the disappearance
of bees. The aim of this project is to examine only two possible reasons for bees’
extinction such as the pesticides and the Varroa mite and suggest possible
solutions.
Although chemical contamination of plants with pesticides fights pests, it
results in mass poisoning and death of bees. Moreover, the bees survived often
bring poisoned nectar and pollen back into hives, which then causes the death of
entire families in winter periods. Most of the plants hold pesticides throughout the
whole lifespan, including flowering phase, the time when the bees are active. Since
doses are low, the bees do not die instantly, but they directly affect younger
generation by feeding them with the nectar collected which is full of pesticides.
Eventually systematic consumption of pesticides weakens bees’ immunity, as well
as their nervous systems and brains. They become more vulnerable to various
illnesses and lose communication and orientation capabilities (UNEP Emerging
issues, 2010, p.9). As a result, they cannot return to the hive and die within a day.
Due to the negative impact on honey bee populations in some European countries
the neonicotinoid-based pesticides have already been banned (Johnson 2010, p.15).
However, according to research when the colonies were fed with pesticides such as
Imidacloprid at amounts likely to be found in the field, the lifespan of the bees
remained unchanged (Oldroyd, 2007, p.7).
The second reason for bees’ extinction is the Varroa mite. Varroa mites are
external honeybee parasites that attack both the adults and the brood, with a
distinct preference for drone brood. They suck the blood and hence weakening and
shortening the life span of bees. Emerging brood may have impairments such as
missing legs or wings. Infestations of Varroa mites will eventually grow among the
bees if not prevented and could lead to destruction of honeybee colonies.
According to the research conducted by USDA, the Israeli acute paralysis virus
(IAPV), which can be transmitted by the Varroa mite, was found in almost all
(96.1%) CCD-affected honey bee colonies samples (Johnson, 2010, p.13).
Table 1. Average honey bee colony losses due to Varroa mite per annum (UNEP
Emerging issues, 2010, p.10)
Region
Percentage
North America
30%
South America
No reports of high losses
Africa
No reports of high losses
Middle East
10 - 85 %
Asia
No reports of high losses
Europe
1.8 - 53 %
Australia
No reports of high losses
Japan
25% of beekeepers reported sudden losses
According to UNEP Emerging issues (2010, p.10) “The Varroa mite, Varroa
destructor, is one of the threats to managed honey bee colonies. Elevated colony
losses reported from the USA, Europe, the Middle East and Japan are related to
high mite infection” as can be seen from Table 1.
Nevertheless, the mites can be controlled with the pesticides which were
developed to kill the mites, apistan, plastic strips, and a triazapentadiene compound
Amitraz, – until the mites became resistant. No better alternatives have been
offered to those pesticides these days. The more beekeepers increase the dose the
less effect it has on the mites, and becomes much more life threatening for the bees
(Oldroyd, 2007, p.5). However according to Schacker (2008, p.39) the Varroa mite
do not appear to be the primary cause of CCD, because there were cases when
CCD has occurred but mites were not present.
To sum up, two possible reasons for bees’ extinction such as the pesticides
and the Varroa mite were discussed in this project. The pesticides might be the
main possible reason for bees’ disappearance, as they are used to the plants, so
directly connected to the bees. Therefore, neonicotinoid-based pesticides were
prohibited in a number of European countries due to harmful effects on bee
colonies. However, several researchers state that some types of pesticides, like
Imidacloprid are not dangerous to bees and can be used further. According to the
research, the Varroa mite might be the second possible reason as it showed the
resistance to most chemicals, although the death of the bees from Varroa
infestation is different from CCD. Therefore, considering these two reasons and
after evaluating them, it seems that effect of pesticides on the bees is more
significant. People should use alternative non-toxic methods in order to reduce
wildlife exposure to insecticides. If no action will be taken today to save the honey
bees, mankind could expect worsening food crisis in future.
List of References:
Johnson, R. (2010). Honey bee colony collapse disorder. Congressional Research
Service 17. Retrieved November 9, 2011, from
http://www.fas.org/sgp/crs/misc/RL33938.pdf
Kluser, S., Neumann, P., Chauzat, M.., Pettis, J. (2010). Global Honey Bee Colony
Disorder and Other Threats to Insect Pollinators. Nairobi, Kenya: UNEP Emerging
Issues
Oldroyd, B. (2007). What's killing american honey bees? Biology Journal, 5(6),
18. Retrieved November 9, 2011, from
http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0050168.
Schacker, M. (2008). A Spring without bees: how colony collapse disorder Has
endangered our food supply. Guilford, the USA: The Lyons Press