A new
type of mosquito trap running on solar electricity and using human odour as bait
has cut the insect population by 70% on a malaria-ridden island in Kenya. The three
year study, conducted by scientists from Netherlands, along with Kenyan and Swiss
scientists, also found 30% fewer malaria victims in houses that had traps than
in those that did not. Although the traps appeared quite effective at lowering
mosquito populations, they had some significant drawbacks. Because they need
power form solar panels, they are relatively expensive. Still, the panes
appealed to residents who could also use them to power a light bulb or charge a
cell phone.
Also the
traps – which resemble lampshades and hang just outside the house – lured in
Anopheles funestus mosquitoes, the most important malaria vector on Rusinga
Island in Lake Victoria, where the test was conducted. But they did not attract
Anopheles gambiae or Anopheles arabiensis, which are much more important
malaria vectors in most of Africa, where more than 400,000 children die of the
disease each year.
Also, the traps needed regular
rebaiting with a blend of five chemical constituents of human odour along with
a chemical that mimicks carbon dioxide plume created by breath. Mosquito traps
releasing carbon dioxide are available in the US, but they can cost hundreds of
dollars; can sometimes require propane tanks, electricity or dry ice; and may
not be effective. The Centers for Disease Control and Prevention recently
tested simple bucket traps that caught egg-laying females by using water and
hay as bait and sticky paper to kill.