A new type of bait using beet juice instead of blood lures the mosquitoes that carry malaria, killing them off quickly, scientists announced recently.
Malaria and other mosquito-borne diseases kills more than 700,000 people all over the globe every year — so this new technique, which is easily scaled up, the scientists say, may mean a turning point in the fight against this scourge, which affects mainly the tropical regions of the Earth.
Using a molecule from a malaria parasite, the researchers, based at Sweden’s Stockhom University, added beet juice, which looks much like blood, to lure the mosquitoes.
Their new study, published in Communications Biology, and reported in Scientific American, describes how they fooled the mosquitoes into drinking the beet juice “blood” that had been laced with poison.
Malaria is longtime scourge of tropical, subtropical regions of the world
Malaria alone kills almost half of all the people who die of mosquito-borne diseases, according to infection biologist and study lead author S. Noushin Emami. Naturally, almost every method under the sun has been used to try to rid the world of these pests, including of course DDT and other extraordinarily toxic chemicals.
Almost all methods used to kill the pests also kill other, desirable insects, such as bees, especially those that include a sugar-based bait.
Lech Ignatowicz, the CEO of a start-up called Molecular Attraction, founded the firm along with Emami as part of the fight against insect-borne diseases all across the world. Any lasting solution to this age-old scourge must be simple to use, he emphasizes.
And this new method fits the bill, he explains, saying that he and his colleagues worked to create a mosquito bait that is not only affordable and scalable but also specific to insects that feed on blood — unlike bees.
Of course, right now especially, it is not only difficult but very expensive for scientists to procure blood for such trials. But as it turns out, Sweden is a huge producer of beets since it uses their sugar for its total sugar production.
And beet juice is very similar to blood in its dark red color, to the point that it can be seen inside the bodies of mosquitoes who are drinking it in. That made for a perfect research scenario, the scientists say.
Now, all they had to do was try to find out how to entice the winged marauders into actually drinking the beet juice in the first place. Emami’s team discovered that Plasmodium falciparum, one of the parasites that causes malaria, releases a chemical called HMBPP into a host animal’s blood back in 2017, she tells Scientific American.
“HMBPP is the taste of a bloody, hot, juicy steak for the mosquitoes,” Emami declares.
She and her team conducted a study which showed that about five times as many mosquitoes drank the beet juice after the researchers added just a smidgen of HMBPP.
Importantly, she says this is what ensures that it is only mosquitoes that are drawn to the bait — to which pesticide is added. The Stockholm University team is also considering natural alternatives to the poisons the they used and of course they will attempt to hit upon something that harms only mosquitoes as a secondary safety measure.
“At the moment the most effective way at fighting mosquitoes is still using pesticides, but we know the pesticides are not only killing mosquitoes but also other insects and other forms of life,” Dr. Lech Ignatowicz states, adding “Plus, they are dangerous for people.
“So if we can use something that is as cheap and scalable as pesticides we can actually eliminate them. Our product is environmentally friendly, doesn’t kill other insects and is harmless to people.”
Targeted toward mosquitoes only
“We can kill thousands of mosquitoes; it takes between 100 and 300 minutes after they have eaten this solution,” Dr. Emami states with evident pride.
Intriguingly, the researchers believe that this method can be used to curb the spread of other diseases spread by insects and other pests – maybe even rats, which not only can spread disease but which still eat vast quantities of grain around the world.
As part of their ongoing research into how they can adapt the bait for wide-scale use, the researchers are considering exchanging beet juice for other substances that are cheaper in tropical areas. Another application they are looking into is the spraying of droplets of their mixture onto leaves, which will entice mosquitoes to drink it when they smell the plasmodium in the bait.