Climate Change to increase British Pestilences
Pastor Dale Morgan
*Climate Change to increase British Pestilences*
By Richard Black
Environment Correspondent, BBC News website
A lot of flies breed in organic waste which people throw away-Dave Goulson
Pesty Fly populations in Britain could soar this century because of
climate change, according to a new study.
Houseflies and bluebottles reproduce more quickly in warmer temperatures.
Using computer models, researchers at Southampton University calculated
that fly and bluebottle populations could rise by nearly 250% by the
year 2080.
Writing in the Journal of Applied Ecology, they warn this might lead to
a rise in infections transmitted by insects, including diarrhoeal disease.
"The rate at which they reproduce is closely linked to temperature,"
said Southampton's Dave Goulson, "particularly the time interval between
an egg being laid and that egg turning into a fly.
"At the optimum temperature of around 32C, it's about 12 days; but in
cooler temperatures it can take a month," he told the BBC News website.
"Our modelling shows that a small rise in average temperatures of 2-3C
would lead to a big increase in the fly population, which is quite
alarming."
The period during which flies are around would also lengthen.
Bottom line
A rise in the fly population could lead to a greater incidence of
fly-borne disease, such as stomach upset and diarrhoea.
The most common cause of diarrhoea in Britain is Campylobacter, a family
of bacteria.
Populations of the housefly (Musca domestica) could rise across the UK.
Image: Science Picture Library
The rate at which flies reproduce should speed up, according the modelling
According to figures from the Health Protection Agency, the number of
cases has risen significantly in recent years, from 28,761 in 1988 to
46,178 in 2003.
Flies are thought to transmit the bacteria, either by carrying small
quantities of contaminated material on their bodies or by regurgitating
or defecating on to food.
Research published earlier this year showed a strong correlation between
the reproductive rate of flies and the incidence of Campylobacter infection.
Nature does provide controls on flies and bluebottles, such as spiders
and swallows; but Dave Goulson does not believe their populations would
be able to increase enough to keep the flies down.
"There are things that we can do though," he said, "such as covering
food in the summer, and taking more care with barbecues and so on.
"The other thing is that a lot of flies breed in organic waste which
people throw away into their dustbins. If more people composted, the
amount of that waste would be reduced."
Two years ago a World Health Organization study concluded that,
globally, climate change has the potential to affect the health of
millions; for example, through the spread of disease-carrying insects.