Israeli researchers say they have developed a substance that attracts and kills mosquitoes infected with the malaria parasite. However, the sweet smelling substance is said to be harmless to people and animals.Scientists at Hebrew University in Jerusalem developed the sugary bait by combining fruit juice oils and boric acid.
The fruit juice gets the attention of the mosquitoes. Boric acid kills the insects when they eat it. The scientists took the boric acid sweet bait to the West African nation of Mali. They sprayed it on plants near man-made ponds. Villagers use water from the ponds during the dry season. But the area is also home to Anopheles gambiae, the mosquito that carries the most deadly form of malaria.
The researchers also placed a sweet-smelling spray on grasses near other ponds. But that spray contained no boric acid.Both substances also contained a substance that would mark any mosquito that came in contact with it. This way the scientists could count the mosquitoes that fed on the bait.Yosef Schlein is an expert on insects that affect human health. Professor Schlein led the sweet bait research. He says thirty-eight days of results show the sweet boric acid bait proved very effective at killing mosquitoes.He said in Mali eighty percent of the females and ninety percent of the males were killed.
But the area is full of little ponds, so it is impossible to stop mosquitoes from flying from an untreated pond to a treated pond. At the ponds treated only with sweet-smelling bait, Professor Schlein says, more than seventy-five percent of mosquitoes fed on the false bait. He says most people do not know that female mosquitoes feed on sweet plant nectars to survive. Their blood feedings are part of reproduction. The Israeli researchers now hope to develop a bait that is even more desirable to the malaria mosquitoes.Boric acid is generally safe for human beings and other mammals. Professor Schlein says scientists might be able to develop a mosquito bait for enclosed spaces. Boric acid has been used to kill other insects, including cockroaches, termites and ants inside homes since the middle of the last century.A report about the malaria mosquito sweet bait was published in Malaria Journal.For VOA Special English I’m Alex Villarreal. You can find this report and more health news at voaspecialenglish.com.
Words in This Story
substance – n. material with particular physical characteristics
sugary – adj. containing sugar
bait – n. a small amount of food on a hook (= curved piece of wire) or in a special device used to attract and catch a fish or animal
anopheles – n. plural anopheles
a type of mosquito (= a small flying insect), especially one that spreads malaria to humans
malaria – n. a disease that you can get from the bite of a particular type of mosquito (= a small flying insect). Malaria causes periods of fever and makes you shiver and feel very cold. It is common in many hotter parts of the world
nectar – n. a sweet liquid produced by flowers and collected by bees and other insects
cockroach – n. a flat, brown or black insect sometimes found in the home
termite – n. (also white ant)
a small tropical insect that eats wood
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