Bottle fly trap - Kenya
Practical Action
Chronic diarrhoea may be a result of a more serious disorder. Diarrhoea is caused by intestinal
pathogens, which are transmitted from the anus of the infected person to the mouth of a susceptible
person. This faecal-oral transmission can take place directly (such as on hands) or via contaminated
food or water. In transferring the pathogens from faeces to food or water, a fly can easily contaminate
the only sources of nutrition available to Maasai families.
It is not just the health of the families that is at stake, but also the health of their livestock, which is
their livelihood. Cows that leak milk in between milking periods are frequent targets for feeding flies.
Cows that leak milk are more likely to have mastitis (a bacterial infection causing inflammation of the
udder), making it likely that the fly will pass on these bacteria.
Biting flies are also a problem for livestock. They often bite on the teats and teat ends of cows where
the skin is thin, which causes wounds and scabs where mastitis bacteria readily grow. The Moraxella
bacteria that cause pinkeye are also prominent in the tears and discharge from calves for flies to feed
on. When fly populations are high, pinkeye spreads rapidly from calf to calf as flies feed from one
moist area to another.
Fly Control
The basic strategy for controlling flies is to reduce the number of potential breeding locations. The
primary fly breeding locations are in fresh manure, in bedding materials such as straw, or around
decaying plant material such as silage or hay. Removal of these breeding sites is the cheapest means
of controlling flies. However, the lifestyle of Maasai families is not always conducive to such changes,
which may negatively affect their coping strategies. More expensive steps for fly control may include
biological control and insecticides, which are unavailable to nomadic Maasai families.
An intermediate measure is the
introduction of low-technology fly
traps. Commercially produced fly
traps of a variety of shapes and
sizes have been used for decades in
the developed world, but due to
their costs have not spread to the
most rural areas of developing
countries. In Kenya the Maasai
families are learning to construct
their own simple fly traps from two
discarded plastic bottles. Traps of
this type have led to a 40 per cent
decline in the fly population and a
30 per cent reduction in new cases
of trachoma.
It has been observed that, after
feeding, flies fly upwards towards
light. The bottle trap makes use of
this trait. Fly bait, such as goat
droppings and cow urine, is added
to a darkened lower bottle. After
the insects have fed, they are
attracted to the light and fly up
the plastic tube and into a clear
bottle above, where they die of
exhaustion and exposure to ultra
violet (UV) light.
The fly trap in use: Photo: Practical Action / Simon Ekless.
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