Why Do Mosquitoes Bite Some People More
Than Others?
Blood type, metabolism, exercise, shirt
color and even drinking beer can make
individuals especially delicious to
mosquitoes
By Joseph Stromberg
SMITHSONIAN.COM
JULY 12, 2013
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16.2K 341 203 861 22 29.2K
You come in from a summer hike covered with
itchy red mosquito bites, only to have your
friends innocently proclaim that they don’t
have any. Or you wake up from a night of
camping to find your ankles and wrists aflame
with bites, while your tentmates are
unscathed.
You’re not alone. An estimated 20 percent of
people , it turns out, are especially delicious
for mosquitoes, and get bit more often on a
consistent basis. And while scientists don’t yet
have a cure for the ailment, other than
preventing bites with insect repellent (which,
we’ve recently discovered, some mosquitoes
can become immune to over time), they do
have a number of ideas regarding why some of
us are more prone to bites than others. Here
are some of the factors that could play a role:
1. Blood Type
Not surprisingly—since, after all, mosquitoes
bite us to harvest proteins from our blood—
research shows that they find certain blood
types more appetizing than others. One study
found that in a controlled setting, mosquitoes
landed on people with Type O blood nearly
twice as often as those with Type A. People
with Type B blood fell somewhere in the
middle of this itchy spectrum. Additionally,
based on other genes, about 85 percent of
people secrete a chemical signal through their
skin that indicates which blood type they have,
while 15 percent do not, and mosquitoes are
also more attracted to secretors than
nonsecretors regardless of which type they
are.
2. Carbon Dioxide
One of the key ways mosquitoes locate their
targets is by smelling the carbon dioxide
emitted in their breath—they use an organ
called a maxillary palp to do this, and can
detect carbon dioxide from as far as 164 feet
away. As a result, people who simply exhale
more of the gas over time—generally, larger
people—have been shown to attract more
mosquitoes than others. This is one of the
reasons why children get bit less often than
adults, on the whole.
3. Exercise and Metabolism
In addition to carbon dioxide, mosquitoes find
victims at closer range by smelling the lactic
acid, uric acid, ammonia and other substances
expelled via their sweat, and are also attracted
to people with higher body temperatures.
Because strenuous exercise increases the
buildup of lactic acid and heat in your body, it
likely makes you stand out to the insects.
Meanwhile, genetic factors influence the
amount of uric acid and other substances
naturally emitted by each person, making some
people more easily found by mosquitos than
others.
4. Skin Bacteria
Other research has suggested that the
particular types and volume of bacteria that
naturally live on human skin affect our
attractiveness to mosquitoes. In a 2011 study ,
scientists found that having large amounts of a
few types of bacteria made skin more appealing
to mosquitoes. Surprisingly, though, having
lots of bacteria but spread among a greater
diversity of different species of bacteria
seemed to make skin less attractive. This also
might be why mosquitoes are especially prone
to biting our ankles and feet—they naturally
have more robust bacteria colonies.
5. Beer
Just a single 12-ounce bottle of beer can make
you more attractive to the insects, one study
found. But even though researchers had
suspected this was because drinking increases
the amount of ethanol excreted in sweat, or
because it increases body temperature, neither
of these factors were found to correlate with
mosquito landings, making their affinity for
drinkers something of a mystery.
6. Pregnancy
In several different studies, pregnant women
have been found to attract roughly twice as
many mosquito bites as others, likely a result
of the fact the unfortunate confluence of two
factors: They exhale about 21 percent more
carbon dioxide and are on average about 1.26
degrees Fahrenheit warmer than others.
7. Clothing color
This one might seem absurd, but mosquitoes
use vision (along with scent) to locate humans,
so wearing colors that stand out (black, dark
blue or red) may make you easier to find, at
least according to James Day, a medical
entomologist at the University of Florida, in
commentary he gave to NBC.
8. Genetics
As a whole, underlying genetic factors are
estimated to account for 85 percent of the
variability between people in their
attractiveness to mosquitoes—regardless of
whether it’s expressed through blood type,
metabolism, or other factors. Unfortunately,
we don’t (yet) have a way of modifying these
genes, but…
9. Natural Repellants
Some researchers have started looking at the
reasons why a minority of people seem to
rarely attract mosquitoes in the hopes of
creating the next generation of insect
repellants. Using chromatography to isolate
the particular chemicals these people emit,
scientists at the UK’s Rothamsted Research lab
have found that these natural repellers tend to
excrete a handful of substances
that mosquitoes don’t seem to find appealing.
Eventually, incorporating these molecules into
advanced bug spray could make it possible for
even a Type O, exercising, pregnant woman in
a black shirt to ward off mosquitoes for good.

http://www.smithsonianmag.com/science-nature/why-do-mosquitoes-bite-some-people-more-than-others-10255934/

Wow! Very eye opening piece

hmmm
no wonder!

choi!

Å good reason ฟһў i won't stop killing mosquitoes