Media Today

[Rick Plant]

Forever young: Many cold-blooded creatures don't age, studies show



Scientists have discovered the secret to eternal youth: be born a turtle.

Two studies published in the journal Science on Thursday revealed scant evidence of aging among certain cold-blooded species, challenging a theory of evolution which holds that senescence, or gradual physical deterioration over time, is an inescapable fate.

Although there have been eye-catching individual reports -- such as that of Jonathan the Seychelles tortoise who turns 190 this year -- these were considered anecdotal and the issue had not been studied systematically, Penn State wildlife ecologist David Miller, a senior author of one of the papers, told AFP.

Researchers have "done a lot more comparative, really comprehensive work with birds and animals in the wild," he said, "but a lot of what we knew about amphibians and reptiles were from a species here, a species there."

For their paper, Miller and colleagues collected data from long-term field studies comprising 107 populations of 77 species in the wild, including turtles, amphibians, snakes, crocodilians and tortoises.

These all used a technique called "mark-recapture" in which a certain number of individuals are caught and tagged, then researchers follow them over the years to see if they find them again, deriving mortality estimates based on probabilities.

They also collected data on how many years the animals lived after achieving sexual maturity, and used statistical methods to produce aging rates, as well as longevity -- the age at which 95 percent of the population is dead.

"We found examples of negligible aging," explained biologist and lead investigator Beth Reinke of Northeastern Illinois University.

Though they had expected this to be true of turtles, it was also found in one species of each of the cold-blooded groups, including in frogs and toads and crocodilians.

"Negligible aging or senescence does not mean that they're immortal," she added. What it means is that there is a chance of dying, but it does not increase with age.

By contrast, among adult females in the US, the risk of dying in a year is about one in 2,500 at age 10, versus one in 24 at age 80.

The study was funded by the US National Institutes of Health which is interested in learning more about aging in ectotherms, or cold-blooded species, and applying them to humans, who are warm blooded.

It's not metabolism

Scientists have long held ectotherms — because they require external temperatures to regulate their body temperatures and therefore have lower metabolisms —- age more slowly than endotherms, which internally generate their own heat and have higher metabolisms.

This relationship holds true within mammals. For example mice have a far higher metabolic rate than humans and much shorter life expectancy.

Surprisingly, however, the new study found metabolic rate was not the major driver it was previously thought.

"Though there were ectotherms that age slower and live longer than endotherms, there were also ectotherms that age faster and live shorter lives," after controlling for factors such as body size.

The study also threw up intriguing clues that could provide avenues for future research. For example, when the team looked directly at average temperatures of a species, as opposed to metabolic rate, they found that warmer reptiles age faster, while the opposite was true of amphibians.

One theory that did prove true: those animals with protective physical traits, such as turtle shells, or chemical traits like the toxins certain frogs and salamanders can emit, lived longer and aged slower compared to those without.

"A shell is important for aging and what it does is it makes a turtle really hard to eat," said Miller.

"What that does is it allows animals to live longer and for evolution to work to reduce aging so that if they do avoid getting eaten, they still function well."

A second study by a team at the University of Southern Denmark and other institutions applied similar methods to 52 turtle and tortoise species in zoo populations, finding 75 percent showed negligible aging.

"If some species truly escape aging, and mechanistic studies may reveal how they do it, human health and longevity could benefit," wrote scientists Steven Austad and Caleb Finch in a commentary about the studies.

They did note, however, that even if some species don't have increasing mortality over the years, they do exhibit infirmities linked to age.

Jonathan the tortoise "is now blind, has lost his olfactory sense, and must be fed by hand," they said, proving the ravages of time come for all.

© 2022 AFP

[Rick Plant]

Jewel thieves in brazen Dutch art fair heist



Flat-cap wearing armed robbers staged a brazen daylight raid on an international art fair in the Netherlands Tuesday, smashing a jewelry case with a sledgehammer in front of terrified visitors.

Police said they pulled over a car and arrested two Belgians in their twenties after the four smartly dressed thieves held up the TEFAF (The European Fine Art Fair) in the southern city of Maastricht.

Dramatic social media images showed the robbers threatening people with what appeared to be handguns before running off with an undisclosed amount of what police called "loot".

The venue was evacuated but visitors were eventually let back into the fair, which draws tens of thousands of people over several days. No one was hurt, police said.

"A stall was raided, they fled and we started the search," Wim Coenen, a spokesman for Limburg province police, told AFP. "There were four suspects, two were arrested."

Dutch media said the display case contained diamond jewelry and other items from London jeweler Symbolic and Chase. There was no comment from the firm.

Police confirmed in a statement that "jewelry was stolen. Additional details about the loot are not being provided at this time."

'Car pulled over'

Dutch police launched a huge search involving a helicopter and sniffer dogs and arrested a 22-year-old and a 26-year-old man nearby, both from Belgium, shortly after.

"These two persons were driving a gray vehicle with a Belgian registration number. This car was pulled over... Their possible involvement is still under investigation," it said.

The TEFAF fair is one of the biggest in Europe, and features hundreds of works, including a 17th-century drawing by a Dutch Old Master on sale for one million euros.

Videos on social media showed the four men -- all wearing flat caps, glasses and smart blazers -- amid scenes of chaos at the art fair.

One struck the jewelry case at least 12 times while burglar alarms wailed.

He finally smashed through the glass, reaching in to pick up something before putting it into a bag.

Two of the men brandished what appeared to be weapons at a bystander, who tried to intervene using a large glass vase full of flowers before backing off.

The men then ran off past a bemused elderly man, who had sat nearby on a bench throughout the drama.

'Still shaking'

Visitor Jos Stassen told Dutch public broadcaster NOS said he had gone to the exhibition on Tuesday to look at the art in peace.

"I suddenly heard a lot of noise and I turn around and suddenly saw those men," he said.

"One started beating and the others kept people away, scared everyone. I also saw a weapon.

"It went very fast and it lasted a very short time but I'm still shaking a little bit."

The fair's general manager Bart Drenth said the owners of the smashed booth are "very shocked", the Dutch news agency ANP reported.

He said the fair's security protocol worked well despite the fact that the armed robbers were able to walk in, adding: "The police were on the scene within minutes."

A TEFAF spokesman added in a statement to AFP that its "security teams worked quickly to disarm an offender... Nobody was injured during the incident."

The phrase "Peaky Blinders" trended on social media in the Netherlands after the raid because the caps worn by the suspects resemble those in the British crime drama of the same name.

It is not the first time the fair has been targeted by criminals.

A ring and a diamond necklace worth 860,000 euros ($1.2 million at the time) belonging to a London jeweler were stolen at the exhibition in 2011.

The Netherlands has also seen a string of art thefts, with paintings by Van Gogh and Frans Hals taken in burglaries in 2020.

© 2022 AFP

[Rick Plant]

Pest … or snack? June bugs are the ‘croutons of the sky’


A June bug (Phyllophaga sp) resting on a paved surface in Guelph, Ont. (Ryan_Hodnett/Wikimedia Commons)


Many people grit their teeth in anticipation of the arrival of June bugs. You might already have had your first run-in with one. Perhaps you heard one clumsily bounce off your window? Maybe you saw one loop around the porch light? Possibly, you felt one tangle its six sticky legs into your hair?

June bugs, also known as May bugs or June beetles, are a group of scarab beetles that are distributed across North America. For a brief period each summer, the adults are common and abundant across many parts of their range.

June bugs are attracted to light, which means we often encounter them at windows and streetlamps in early summer. Due to their large size and distinctive appearance, they are rather conspicuous among the millions of other insect species we share our world with.

Whether you consider them friend, foe or a neutral party, here are some insights into these misunderstood creatures to celebrate the advent of June bug season.

Hundreds of different species of June bugs

June bugs are found within the genus Phyllophaga, derived from the Greek phyllon (leaf) and phaga (eat). This name is a literal description of the adult’s habit of feeding on plant leaves.

There are more than 800 species of June bugs known to science and more are discovered every year. Adult beetles are usually blackish or reddish brown in colour, and tend to be very hairy on their fronts. While June bug species have many external similarities, their genitalia are very distinctive — with the male organs resembling a scoop, a claw or a fork. Taxonomists often confirm the identity of the species, or describe new species, by carefully examining the genitalia.


Four species of Polyphaga showing the similar external morphology and distinctive male genitalia. (University of Nebraska State Museum, entomology division)


June bug grubs live below ground for years

When you encounter a June bug flying or crawling about, you are looking at a full-grown adult. Just like butterflies and moths, June bugs grow through a process known as “holometabolous development.” They pass through several stages: egg, larva, pupa and adult. Just as with butterflies, adult June bugs look and behave completely different from the larvae.


Adult next to larva of a Phyllophaga species scarab collected from turfgrass. (Whitney Grandshaw/www.invasive.org)


Each June bug starts as a pearl-like egg laid in the soil. Each egg hatches into a c-shaped larva known commonly as a white grub. White grubs feed on the roots of plants, disrupting the uptake and transport of water and nutrients.

In high densities, June bugs can be serious pests of ornamental and agricultural plants, lawns and golf courses. Larvae spend at least a year in the soil, and in some cases take as much as four to five years to reach maturity.

In late spring, the larva metamorphoses into a pupa, and then into the adult beetle. Armed with wings and developed gonads for mating, the June bugs will emerge from the soil and take to the night sky with the goal of feeding, finding a mate and reproducing, thus beginning the cycle anew.

June bugs are food for many wild animals

Although many people find June bugs unsettling, they play an important role in helping nutrients cycle through ecosystems. By chowing down on grass roots, June bugs concentrate nutrients into juicy (larva) and crunchy (adult) calorie-rich packages that are consumed by a variety of other organisms.

June bugs are a rich source of protein (40 to 50 per cent) and fat (seven to 18 per cent). Many wild animals such as skunks, raccoon and several bird species consume June bugs across all stages of their life cycle. In the process of foraging for June bug larvae, animals often dig up soil, damaging crops, gardens, lawns and golf greens in the process.


An Eastern Bluebird chows down on a June bug at Thomson’s Lake State Park, N.Y. (olitimm/flickr)


Aside from vertebrate predators, June bugs are an important food source for many other insects. A study based in southern Québec found that 29 species of insect used the June bug (Phyllophaga anxia) as a source of food.

One of the remarkable species that feeds on June bugs is Pelecinus polyturator. It is a large wasp (about seven centimetres long) that primarily reproduces asexually, and is found from northern Argentina to southern Canada. Pelecinus polyturator uses its long ovipositor to lay its eggs into white grubs, which eat and kill their host after hatching.


This large parasitic wasp lays its eggs into June bug larvae feeding in the soil. (hspauldi/flickr)


Some people eat June bugs too

Much of the discussion around entomophagy (eating insects) in North America is centred on industrially reared insects like crickets and mealworms. Wild-foraging insects can also play an important role in supplying insects for human consumption, as is the case with June bugs.

Historically, the Bear River people in northwestern California ate fire-roasted June bugs. Today, many people collect adult June bugs from lights or dig larvae from the soil for recipes. They crush them and bake them into biscuits, sprinkle them onto salads as “croutons of the sky,” a term coined by Jonathan Bobryk of Nova Scotia, or even fill cooked larvae with cheese and wrap them in bacon

If you come across an adult June bug this spring, maybe give it a closer look. This chunky insect could very well be older than any of the babies and toddlers in your life.

If you squish it under your foot, you might be saving your lawn from the wrath of hungry white grubs, but you also might be robbing a barred owl, a pelecinid wasp, or your neighbour of a protein-rich morsel.

https://theconversation.com/pest-or-snack-june-bugs-are-the-croutons-of-the-sky-154035

[Rick Plant]

How Cassidy Hutchinson's testimony could lead to a seditious conspiracy charge against Trump

Strongest evidence yet tying Trump to mob violence, some analysts say


Donald Trump speaks during the Jan. 6, 2021, rally that preceded the attack on the U.S. Capitol. Recent testimony from former White House aide Cassidy Hutchinson that Trump knew many people in the crowd were armed could see him charged with seditious conspiracy, some legal analysts say. (Evan Vucci/The Associated Press)


The gripping testimony of Cassidy Hutchinson before the Jan. 6 committee could provide federal prosecutors with the legal ammunition to charge former U.S. president Donald Trump with seditious conspiracy, some legal analysts say.

The ex-aide to former White House chief of staff Mark Meadows made a series of startling claims at the House committee's abruptly called hearing on Tuesday — the most potentially damaging of which was that Trump knew people gathering near the Capitol early on Jan. 6, 2021, had weapons.

But he told officials to let them into a rally, still armed, after which they'd "march to the Capitol," Hutchinson said.

"The thing that really struck me was how directly it tied Trump to the violence, the assault on the Capitol itself," said Randall Eliason, a former assistant U.S. attorney for the District of Columbia.

"Pretty compelling, pretty damaging for Trump."

Only the Justice Department, which has been conducting its own investigation, can lay charges, but the House panel can send the department criminal referrals.

Prior hearings have focused on Trump's non-violent efforts to overturn the election, whether by pressuring state officials or Vice-President Mike Pence. But Hutchinson's testimony "was really the strongest evidence we had directly tying Trump into the mob violence in the Capitol," Eliason said.

'They're not here to hurt me'

Hutchinson quoted Trump as directing his staff, in profane terms, to take away the metal detectors, known as magnetometers or mags, that he thought would slow down supporters who'd gathered in Washington.

"'They're not here to hurt me. Take the f-in' mags away. Let my people in. They can march to the Capitol from here," Hutchinson quoted Trump as saying.


Hutchinson testifies before the Jan. 6 committee in Washington on Tuesday. (Jacquelyn Martin/The Associated Press)


Stuart Gerson who was acting U.S. attorney general during the early Clinton administration, says that's significant.

"Arguably to a jury you can say — with an evidentiary reason for saying it — that he joined the conspiracy," Gerson said.

Previously, Trump's role in trying to prevent Congress from certifying the 2020 presidential election has led to speculation that he could face charges of conspiracy to defraud the United States and conspiracy to obstruct congressional proceedings.


Pro-Trump rioters try to open a door to the Capitol. (Jose Luis Magana/The Associated Press)

However, Hutchinson's testimony suggests a potential case against him for seditious conspiracy — an effort to overthrow the government by force — some analysts say. The Justice Department has laid some seditious conspiracy charges against leaders of the Proud Boys and OathKeepers for their role in the riot.

Glenn Kirschner, also a former assistant U.S. attorney for the District of Columbia, thought Hutchinson's evidence is "a bit of a game-changer" because Trump was told the crowd was armed and dangerous.

"I can tell you, as a career prosecutor, I would argue all day long that the reasonable inference a jury should draw from the statement: 'Take down the metal detectors because the armed rioters are not here to hurt me' is 'They are here to hurt the folks up the street who are in the Capitol certifying the win of my opponent,'" Kirschner said.

'Greater certainty' of charge

Hutchinson's testimony also lends support to both the conspiracy to obstruct congressional proceedings charge, and seditious conspiracy, Kirschner said.

"He's probably bought himself a greater certainty that he will be criminally charged," Kirschner said.

Danya Perry, a former deputy attorney general for the State of New York and former assistant United States attorney for the Southern District of New York,  says she agrees Hutchinson really "moved the ball" on a potential charge of seditious conspiracy.

Hutchinson's testimony put together one of the means by which the president was willing to try to achieve his goals — by "weaponizing this mob," Perry said.

It's now conceivable that there could come a time when United States vs. Donald J. Trump and others could be seen on a docket sheet for conspiracy charges, she said.

 She asks, rhetorically: Were his actions "qualitatively or substantively" different from those of the Proud Boys or OathKeepers?

"I think, what we saw, they're of a kind."

 Barbara McQuade, a former U.S. attorney for the Eastern District of Michigan, says Hutchinson's evidence certainly makes Trump look even more reckless than first believed.

But any obstruction, defrauding or seditious conspiracy charges would require more evidence, she says.

"But I don't think her testimony alone established that. I think she filled in some parts of the picture. And it's important to know the whole story," McQuade said.

"Prosecutors are looking for evidence of intent. I heard a lot of reckless intent, but not a lot of purposeful intent," she said.

"Before you charge a former president with charges as serious as that, I think you're going to want more than just an inference. I think you're going to want direct evidence that this was the plan."

Credibility as witness

Some have questioned Hutchinson's credibility, particularly regarding her testimony that she was told Trump fought a security official for control of the presidential SUV on Jan. 6 and demanded to be taken the Capitol as the insurrection began, despite being warned earlier that day that some of his supporters were armed.

A number of media outlets have reported that the agent driving the vehicle and another security official are willing to testify that didn't happen. Trump himself has also denied it.

Lawyers for Hutchinson have since released a statement saying she stands by her testimony.

Eliason says Hutchinson's strength as a witness depends on which part of her evidence we're talking about.

"There was definitely things that she was just repeating that other people told her. But a lot of it was stuff that she witnessed, conversations that she witnessed," she said.

And, prosecutors wouldn't just use Hutchinson's testimony. It would be a starting point to find other witnesses.

"Obviously, [some are] trying to suggest, well, if she was wrong about this story, why believe anything else she said," Eliason said.

Her testimony about what happened in the SUV "was an example of something that clearly was a second-hand kind of anecdote she didn't claim to witness personally. And the details of that are much less important than details of things that she actually witnessed."

WATCH in link below: Trump wanted armed people at rally, former aide says:

WATCH in link below: Previously unseen riot footage gives new details:

https://www.cbc.ca/news/world/donald-trump-cassidy-hutchinson-charges-1.6505547

[Rick Plant]

Rep. Liz Cheney 'confident' in Cassidy Hutchinson's testimony

Her interview will air in full Sunday on "This Week with George Stephanopoulos."



Republican Rep. Liz Cheney told "This Week" co-anchor Jonathan Karl in an exclusive interview that she has full faith and confidence in the testimony of Cassidy Hutchinson, the 26-year-old former Trump White House aide who delivered explosive testimony about the Capitol riot during a highly publicized hearing this week.

"As you know, there's an active campaign underway to destroy her credibility. Do you have any doubt at all in anything that she said to you?" Karl asked Cheney.

"I am absolutely confident in her credibility. I'm confident in her testimony," Cheney told Karl in a wide-ranging interview set to air in full on ABC's "This Week with George Stephanopoulos" on Sunday.

"I think that what Cassidy Hutchinson did was an unbelievable example of bravery and of courage and patriotism in the face of real pressure," said Cheney, who is vice chair of the Jan. 6 committee.

The witness, Hutchinson, a former top adviser to then-President Donald Trump's chief of staff Mark Meadows, spent some two hours divulging extraordinary details about what she said went on behind the scenes leading up to, during and after the attack.

Hutchinson sat for multiple closed-door transcribed interviews with the committee during its year-long inquiry but on Tuesday, she spoke publicly for the first time during the committee's sixth publicized hearing.

She described in detail how she was told about Trump's desire to go to the Capitol on Jan. 6 after he spoke at a rally near the White House -- and how Trump became furious when he was told it wasn't safe or advisable for him to be there.

"We have real confidence as a committee that she testified honestly, and in her credibility, and I think the world saw that -- she testified under oath, and her credibility is there for the world to judge," Cheney said in her interview with Karl.

"She's an incredibly brave young woman," Cheney added. "The committee is not going to stand by and watch her character be assassinated by anonymous sources and by men who are claiming executive privilege."

On Wednesday, Hutchinson's lawyers released a new statement amid pushback on her testimony.

"Ms. Hutchinson stands by all of the testimony she provided yesterday, under oath, to the Select Committee to Investigate the January 6th Attack on the United States Capitol," Hutchinson's counsel, Jody Hunt and William Jordan, said in the statement to ABC News.

https://abcnews.go.com/Politics/rep-liz-cheney-confident-cassidy-hutchinsons-testimony/story?id=85943993

[Rick Plant]

'Shadowy' GOP-linked group in Houston knocking on doors in mostly Black neighborhood seeking sensitive voter info

A Houston resident said two men wearing Texas Election Network badges came to her door asking her to sign an affidavit verifying her voter address "under penalty of perjury."

The Harris County attorney's office is investigating complaints that members of the Republican-connected grass-roots organization were snooping around the Sunnyside neighborhood, where about 75 percent of residents are Black and 20 percent are Hispanic, and asking residents to sign official-looking documents, reported the Houston Chronicle.

“The people canvassing residents are grass-roots volunteers for the nonprofit organization called Texas Election Network and they are wearing badges that clearly state the name of the organization with the nonprofit registration number on the back," said Alan Vera, chair of the county GOP's ballot security committee and a Texas Election Network board member. "These volunteers are not employees of any political party. The nonprofit’s mission is to empower citizens to ensure and protect fair and transparent elections."

The county elections office issued a warning Wednesday against "scammers" pretending to be government officials and collecting sensitive personal information, but the county attorney's office said they had not found evidence that anyone had misrepresented themselves as a public employee, which is illegal.

"I'm sure they'll say they're just a bland nonprofit, but to a voter who does not have a law degree, who does not have a background in law enforcement, you are a lot more likely to believe that this is some kind of quasi-official visit," said James Slattery, senior staff attorney with the Texas Civil Rights Project. "This is one of the precise situations I have been most worried about this election — people in shadowy volunteer groups who suggest in one way or another that they are acting under official authority questioning the eligibility of voters directly by knocking on their doors."

Read More Here:

https://www.houstonchronicle.com/news/houston-texas/houston/article/Harris-County-looking-into-GOP-connected-group-17277971.php

[Rick Plant]

Viruses can change your scent to make you more attractive to mosquitoes, new research in mice finds



Mosquitoes are the world’s deadliest animal. Over 1 million deaths per year are attributed to mosquito-borne diseases, including malaria, yellow fever, dengue fever, Zika and chikungunya fever.

How mosquitoes seek out and feed on their hosts are important factors in how a virus circulates in nature. Mosquitoes spread diseases by acting as carriers of viruses and other pathogens: A mosquito that bites a person infected with a virus can acquire the virus and pass it on to the next person it bites.

For immunologists and infectious disease researchers like me, a better understanding of how a virus interacts with a host may offer new strategies for preventing and treating mosquito-borne diseases. In our recently published study, my colleagues and I found that some viruses can alter a person’s body odor to be more attractive to mosquitoes, leading to more bites that allow a virus to spread.

Viruses change host odors to attract mosquitoes

Mosquitoes locate a potential host through different sensory cues, such as your body temperature and the carbon dioxide emitted from your breath. Odors also play a role. Previous lab research has found that mice infected with malaria have changes in their scents that make them more attractive to mosquitoes. With this in mind, my colleagues and I wondered if other mosquito-borne viruses, such as dengue and Zika, can also change a person’s scent to make them more attractive to mosquitoes, and whether there is a way to prevent these changes.

Watch:

A number of factors can make you more attractive to mosquitoes, including the odors you emit.

To investigate this, we placed mice infected with the dengue or Zika virus, uninfected mice and mosquitoes in one of three arms of a glass chamber. When we applied airflow through the mouse chambers to funnel their odors toward the mosquitoes, we found that more mosquitoes chose to fly toward the infected mice over the uninfected mice.

We ruled out carbon dioxide as a reason for why the mosquitoes were attracted to the infected mice, because while Zika-infected mice emitted less carbon dioxide than uninfected mice, dengue-infected mice did not change emission levels. Likewise, we ruled out body temperature as a potential attractive factor when mosquitoes did not differentiate between mice with elevated or normal body temperatures.

Then we assessed the role of body odors in the mosquitoes’ increased attraction to infected mice. After placing a filter in the glass chambers to prevent mice odors from reaching the mosquitoes, we found that the number of mosquitoes flying toward infected and uninfected mice were comparable. This suggests that there was something about the odors of the infected mice that drew the mosquitoes toward them.



Volunteering in a mosquito study may require a few bites.

Panyawat Boontanom/EyeEm via Getty Images

To identify the odor, we isolated 20 different gaseous chemical compounds from the scent emitted by the infected mice. Of these, we found three to stimulate a significant response in mosquito antennae. When we applied these three compounds to the skin of healthy mice and the hands of human volunteers, only one, acetophenone, attracted more mosquitoes compared to the control. We found that infected mice produced 10 times more acetophenone than uninfected mice.

Similarly, we found that the odors collected from the armpits of dengue fever patients contained more acetophenone than those from healthy people. When we applied the dengue fever patient odors on one hand of a volunteer and a healthy person’s odor on the other hand, mosquitoes were consistently more attracted to the hand with dengue fever odors.

These findings imply that the dengue and Zika viruses are capable of increasing the amount of acetophenone their hosts produce and emit, making them even more attractive to mosquitoes. When uninfected mosquitoes bite these attractive hosts, they may go on to bite other people and spread the virus even further.

How viruses increase acetophenone production

Next, we wanted to figure out how viruses were increasing the amount of mosquito-attracting acetophenone their hosts produce. Acetophenone, along with being a chemical commonly used as a fragrance in perfumes, is also a metabolic byproduct commonly produced by certain bacteria living on the skin and in the intestines of both people and mice. So we wondered if it had something to do with changes in the type of bacteria on the skin.

To test this idea, we removed either the skin or intestinal bacteria from infected mice before exposing them to mosquitoes. While mosquitoes were still more attracted to infected mice with depleted intestinal bacteria compared to uninfected mice, they were significantly less attracted to infected mice with depleted skin bacteria. These results suggest that skin microbes are an essential source of acetophenone.



Viruses can alter the skin microbiome to increase the presence of bacteria like Bacillus, which produce mosquito-attracting odors.

Marc Perkins/Flickr, CC BY-NC

When we compared the skin bacteria compositions of infected and uninfected mice, we identified that a common type of rod-shaped bacteria, Bacillus, was a major acetophenone producer and had significantly increased numbers on infected mice. This meant that the dengue and Zika viruses were able to change their host’s odor by altering the microbiome of the skin.

Reducing mosquito-attracting odors

Finally, we wondered if there was a way to prevent this change in odors.

We found one potential option when we observed that infected mice had decreased levels of an important microbe-fighting molecule produced by skin cells, called RELMα. This suggested that the dengue and Zika viruses suppressed production of this molecule, making the mice more vulnerable to infection.

Vitamin A and its related chemical compounds are known to strongly boost production of RELMα. So we fed a vitamin A derivative to infected mice over the course of a few days and measured the amount of RELMα and Bacillus bacteria present on their skin, then exposed them to mosquitoes.

We found that infected mice treated with the vitamin A derivative were able to restore their RELMα levels back to those of uninfected mice, as well as reduce the amount of Bacillus bacteria on their skin. Mosquitoes were also no more attracted to these treated, infected mice than uninfected mice.

Our next step is to replicate these results in people and eventually apply what we learn to patients. Vitamin A deficiency is common in developing countries. This is especially the case in sub-Saharan Africa and Southeast Asia, where mosquito-transmitted viral diseases are prevalent. Our next steps are to investigate whether dietary vitamin A or its derivatives could reduce mosquito attraction to people infected with Zika and dengue, and subsequently reduce mosquito-borne diseases in the long term.

Penghua Wang, Assistant Professor of Immunology, University of Connecticut

https://theconversation.com/viruses-can-change-your-scent-to-make-you-more-attractive-to-mosquitoes-new-research-in-mice-finds-185833