8/01/2020

Headline, August 02 2020/ ''' '' MOSQUITOES -HUMAN-BITING- MUNITIONS '' '''


''' '' MOSQUITOES -

HUMAN-BITING- 

MUNITIONS '' '''




THE ORIGINAL REASON THIS SPECIES evolved to be a human specialist had to do with its use of human water.

The Current Biology research paper focused on the evolutionary history of the mosquitoes, but its findings might have implications for public health.

The results, combined with climate and population data from the United Nations, suggest that there will be more human - biting mosquitoes in sub-Saharan Africa by 2058, caused mostly by urbanization.

MOSQUITOES HAVE BEEN CALLED the deadliest animal in the world: tiny creatures so dangerous that genetic engineering may be necessary to win the battle against them.

But not all mosquitoes are equally responsible for devastating the human population by spreading disease. Out of thousands of species only a few like to bite humans.

And even with the same species, mosquitoes from different places can have different preferences. Why do some find us irresistible while others remain unimpressed?

To answer that question, a team of Princeton University researchers, working with a large network of  local collaborators, spent three years driving around sub Saharan Africa collecting the eggs of Aedes aegypti mosquitoes, which are responsible for Zika yellow fever and dengue.

There are two subspecies of Aedes aegypti : one that prefers humans and one that prefers animals, mostly populations are a genetic mix.

After sending the eggs to New Jersey to grow new colonies, and then tempting the insects with the sweet smells of humans and of rodents, the researchers found that the more human-loving mosquitoes tended to come from areas with a dry climate and dense human population.

That, in turn, is because humans provide the water mosquitoes need to breed.

''There had been quite a bit of speculation in the literature that the original reason this species evolved to be a human specialist had to do with its use of human water,'' said Lindy McBride, a Princeton neuroscientist and an author on the study. ''It's easy to come up with a hypotheses, but what was incredibly surprising was that you could actually see evidence for that.''

Like all mosquitoes, Aedes aegypti lays its eggs on water, so the project began by setting out thousands of ovitraps, the plastic cups lined with seed paper and filled with water and dirty leaves to simulate the ideal breeding environment.

The ovitrops were placed in big cities and in rural areas, in an effort to span environmentally diverse locations, said Noah H.Rose, a postdoctoral fellow at Princeton and co-author of the study published last week in Current Biology. A few days later someone came back and checked for eggs.

After the eggs were sent to the Princeton Lab and new colonies were established, the next step was figuring out why some populations evolved to become generalists and some to become so-called  human specialists.

This required deploying an olfactometer : a big plastic box full of mosquitoes, with two removable tubes in it, one containing a guinea pig and the other holding part of a human.

''I was just sitting with my arm in the tube doing this trial over and over again,'' Dr. Rose said. He spent ''a couple of months of my life'' as mosquito bait, repeating the experiment a hundreds of times while listening to audiobooks. Screens kept him and the guinea pig from actually being bitten.

Within minutes, mosquitoes, attracted to either the human or the non-human scent, would pick a tube and enter it. Later, the tubes were removed to count the mosquitoes and figure out how many preferred Dr. Rose.

The Honor and Serving of the Latest Global Research on Mosquitoes, Humans and Biology, continues. The World Students Society thanks author Angela Chen.

With respectful dedication to the Scientists all, Biologists, Students, Professors and Teachers of the world. See Ya all prepare and register for Great Global Elections on The World Students Society : wssciw.blogspot.com and Twitter - !E-WOW! - The Ecosystem 2011 :

''' Nature's - Natural '''

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