Scientists discover an unlikely way to prevent mosquitoes from stinging you

TThe teasing temptation of a sweet treat can often take over. But do not worry, we are not the only ones. The sweet substance that is so difficult to resist our sweet tooth is also extremely attractive to mosquitoes. And, according to new research, sugar could, for once, help maintain the health of the pests in our blood-rich organs.

But do not start mixing sugar water for the moment – you could do as much harm as harm.

We have known for a long time that sugar is an important source of energy for mosquitoes. In fact, it is better than the blood to fuel the processes of flight and survival. Only female mosquitoes feed on blood because it provides the essential nutrients for making their eggs.

Of course, this thirst for blood generates a terrible burden of disease in the world, often in countries least equipped to deal with it. Among the hundreds of scientists around the world working to reduce the threat of mosquitoes, one promising avenue is to study the interactions between their desires for sugar and blood.

The new research, published in PLOS Biology, undertake to investigate this. He focused on the Asian tiger mosquito (Aedes albopictus), an invasive species that has infiltrated on all continents, is closely associated with humans and very difficult to suppress, making it a particularly dangerous vector for the transmission of diseases such as dengue, yellow fever and the Zika virus.

See also: How millions of mosquitoes parasitized by robots can fight Zika

The research team discovered that feeding sweet solutions of young tiger mosquitoes caused a physiological response similar to that caused by a blood supply. Importantly, this then delayed their search for the red velvet blood of a human host.

Interestingly, the researchers found that eating sugar resulted in increased levels of a protein called vitellogenin in mosquitoes. Vitellogenin is an important component in the production of egg yolk that provides nutrients to the offspring of unborn mosquitoes. Normally, vitellogenin is produced when receptors detect specific nutrients that mosquitoes collect in blood meals.

By using gene interference experiments, researchers were able to identify a specific gene associated with vitellogenin that, once eliminated, has restored the appeal of mosquitoes to humans. This is exciting because it highlights the targeting potential of this gene as a way to reduce a host's search behavior and, in turn, the transmission of deadly diseases affecting millions of people. people.

Work to do

This research constitutes a significant advance in understanding the physiological mechanisms that influence the feeding behavior of mosquitoes. However, there is still a lot of work to be done. As the authors know, mosquito sugar alone can not be used as a control method in the real world.

There are several reasons for this, but the most important is that the effects of sugar on mosquito behavior can vary considerably, even within this single species. For example, while the reduction in human attraction was maintained in young adult mosquitoes, when older women fed on sugar, they remained strongly attracted to humans and had increased nutrients. This is not a desirable result. The physical condition, the quality of the mosquito's feeding as a larva, its mating and its previous spawning can also affect the effect of sugar on eating behavior.

Things get even more complex when other species of mosquitoes are taken into account. For example, high levels of vitellogenin weaken the immune system of the malaria-carrying African mosquito (Anopheles gambiae), making it more likely to contract and transmit malaria. Increased vitellogenin is clearly not always a good thing.

Leaving the sugar aside for mosquitoes may deter young mosquitoes from biting you, but this will strengthen the resistance of older mosquitoes and may weaken the defenses of other mosquito species. However, we may be able to genetically modify or genetically treat tiger mosquitoes with hormones that increase vitellogenin levels in the absence of sugar, thus eliminating this trade-off. Since, in most cases, mosquitoes catch pathogens at the first meal, such control methods could significantly delay mosquitoes' first blood meal, making them infective for a shorter period of time.

Of course, at this early stage, it is difficult to estimate the potential effectiveness of control measures modifying vitellogenin. It is important to note that there is still a long way to go before a single response is created for mosquitoes. So continue to follow the best advice on your travels.

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This article was originally published on The Conversation by Richard Halfpenny. Read the original article here.