Thanks to the research of two scientists, the world may soon be able to rid itself of malaria-carrying mosquitoes. The key: insecticide-spiked nectar.Just about everyone has a sweet tooth — even mosquitoes. And researchers are ?using the love and need that these disease-?carrying pests have for sugar as a way to control the spread of malaria, a scourge responsible for more than half a million deaths annually, according to the World Health Organization. John Beier, a vector biologist at the University of Miami, says that this is the first new promising approach to mosquito control in decades. “The methods that we have are not doing a good-enough job [fighting the disease],” he says.
Until now, the primary means of ridding the world of the pesky and dangerous insect consisted of insecticide-?treated bed nets and spraying with insecticides — to little or no avail. The new method, though, which has attracted the interest and funding of the Bill & ?Melinda Gates Foundation, takes advantage of the behaviors and environments in which mosquitoes live and, as Kate Aultman, a senior program officer with the ?foundation explains, “can complement or even replace
So, how does it work?
Many people erroneously believe that mosquitoes need blood to survive. However, it’s only the female mosquito that requires blood, and she needs it only to develop her eggs — not to survive. The truth is, ?mosquitoes need sugar to live; both males and females require it for their life’s activities. They get this sugar from fruit, honeydew and the nectar of plants, which is key, because the new method involves spiking the nectar that mosquitoes feed on with either boric acid or a low-risk insecticide that has little to no effect on birds or other insects that may feed on the bait. And it’s proving to be quite successful: In small-scale studies using the toxic sugar in the West African nation of Mali and in the deserts of Israel, 90 percent or more of the local malaria-vector mosquitoes were killed.
The idea of using sugar to lure mosquitoes to their deaths — known as the attractive-toxic-sugar-bait (ATSB) method — was developed by Yosef Schlein and Günter Müller, medical entomologists at the Hebrew University of Jerusalem. While they have been studying the sugar-feeding behavior of mosquitoes for 20 years — “It was an interesting subject. Nobody had touched it,” Schlein says — it was only within the last six that they were able to use the behavior to develop a control method. Through research, tests and experiments, Schlein and Müller began to understand the importance of sugar feeding and the critical role the availability of nectar and sugar-based foods plays in the life cycle and populations of mosquitoes. From there, the ATSB method became a clear ?option. Adriana Costero, vector biology program officer at the National Institute of Allergy and Infectious Diseases, believes that ?simple, straightforward? research such as this is crucial to the development of innovative approaches like ATSB. While she’s not involved in the toxic-sugar-bait research, she specializes in studying insect-borne diseases and says that “Basic research that might not seem relevant to the public may lead to something that has an impact.”
Applying the ATSB method can be decidedly? low-tech and cheap. In some cases, the studies have used a “bait station,” a cocktail of overripe fruit, sugar and low-toxicity insecticide in a plastic soft-drink bottle. A cloth wick is pushed through a hole cut in the side of the bottle, and it absorbs the liquid from the fruit-insecticide mixture. In another, a concoction of the insecticide mixed with sugar, the juices of overripe guava and honey melon (the fruits fussy mosquitoes seem to prefer the most) is sprayed on vegetation in a test area.