This morning I squashed a mosquito in the kitchen and it released a rather dramatic splotch of blood. Clearly it had eaten recently. But the odd thing was that neither I nor any of my family members had been bitten, and all the windows and doors in the house were shut. So we don’t know whose blood it was. And this raised a bunch of mosquitoey questions:
How long would a mosquito still contain a splotachable amount of blood after eating? Could this have been from a meal a few days ago, either in our house or somewhere else?
Do mosquitoes that bite people also bite animals? We have cats but it seems to me that it might be difficult to bite through the fur.
And this reminded me of some other questions too:
Do mosquitoes prefer certain body parts over others? Almost all of my bites usually are on my lower legs/feet and forearms/hands. I realise that the other body parts are usually better covered, but why then am I seldom bitten on my head/face/neck?
Once they have bitten you, it takes several days for the itch to disappear. What is the mechanism for this disappearance? Do the saliva proteins that causes the itch bleed out (assuming you scratch it)? Does your body break them down? Does they decay on their own?
I have noticed that when it is really hot out the mosquitoes don’t come, and likewise when it is cold there are none either. What is the ideal temperature for mosquitoes then?
I am referring to your run of the mill European house mosquito…
You didn’t google? Histamines:
When a mosquito bites, it uses its straw-like mouthparts to pierce the skin and draw blood. While doing so, the mosquito injects some of its own saliva, which contains an anticoagulant and certain proteins. The anticoagulant prevents blood from clotting around the mosquito’s mouth, which could cause it to get stuck. The proteins released by the mosquito trigger the body’s immune system, which releases histamine, a compound that enables white blood cells to access the affected area. The increased blood flow and white blood cell count brought on by histamine cause inflammation and swelling. Histamine also sends a signal to the nerves surrounding the bite, which is what ultimately causes mosquito bites to itch.
Mosquitoes certainly bite animals. The animal’s fur may make it hard for the mosquito to reach the skin but it is not 100% protection (consider remote places with very few or no humans that are still filled with mosquitoes). Indeed, that is usually the way dogs get heartworm which we take pains to protect them against.
If you’re talking red blood, somewhere between 24-36-ish hours. We can get usable DNA out of mosquito bloodmeals for about that time (48 hours is pushing it); after which it’s too far digested to be suitable and by that time it’s brown and degraded. usually completely digested by about 3-4 days.
This depends on the species but yes, absolutely. Mosquitoes certainly have host preferences (some prefer to feed on humans, some on cattle, or birds, or frogs etc…) but if they’re hungry and a non-preferred host is sitting there sure they’ll feed. Using DNA analysis we can identify the source of mosquito bloodmeals and we (and others) have found many instances of multiple feedings on different host species.
Yes they can feed on cats, dogs, etc… They can feed through the fur but there are plenty of spots on a cat/dog that aren’t fur-covered (feet, nose, ears (this is a common feeding site), also around the eyes.
Many mosquitoes are attracted to odor volatiles that come off the bacteria found on feet, which is why you often get bitten around the ankles (there’s some classic research showing some mosquitoes are attracted to limburger cheese which has some of the same volatiles). But it depends on the species (I was at a a BBQ yesterday and got the crap bitten out of me on my neck). You can get bitten anywhere the mosquitoes can access.
The “itch” is an allergic reaction your body has to components in the mosquito saliva. The itch disappears when your body’s immune response stops reacting. The saliva components get cleared pretty quickly but your immune response sticks around for much longer. Everyone reacts differently to mosquito bites, and can react differently to different species.
Don’t scratch your bites, this will make them last longer, itch more, and can cause secondary infections if you open them up. Use very hot water instead, it will completely kill the itch for up to 8 hours due to histamine depletion.
Yes mosquitoes have a thermal optimum; they’re “cold-blooded” (ectotherms). Too cold and they can’t be active. Save for too hot. Again, the specific optimal temperature depends on the species.
Lewis & Clark commented frequently in the Journals of their 1803-1806 expedition across North America that along with the immense herds of elk, deer, buffalo, wolves etc, in a “common and boundless plain” there were also absolutely staggeringly huge clouds of mosquitos that filled the sky and accompanied them.
In some places they reported the mosquitos were so thick, they completely covered the animals in some herds, some deer herds were obviously sick and emaciated. Clark attributed this to the mosquitos sucking their blood out.
I’ve noticed lately that I seem to have two different reactions to mosquito bites. In one, I barely notice them at first but in 24-36 hours they itch like hell and take days to resolve. In the other I note them immediately, they itch immediately but not as severely as in the former, and they’re gone in 12 hours or so. Each reaction seems to occur at a different point in time in the mosquito season. What’s up with that? Two different species of mosquito appearing at different times? Or . . .
Do you have an idea of the actual temperature range? We are entering the in-between season here and it would be good to have a numerical idea of which nights we need to be on the lookout and which we don’t.
If I may ask, are you a professional mosquitologist?
Related to where mosquitoes land on you, why do they sometimes buzz your ear when you are asleep? It usually wakes me up, then I’ll turn on the lights and hunt it down, then dispatch it. Seems counter-productive for the mosquito - it could have just landed quietly on my shoulder or arm and had a peaceful meal. Perhaps my breath?
Related to that - why do they buzz at all? Seems like evolution would have favored a silent mosquito.
Mosquitoes in the dark do not know where you hear, what an ear is or where it is. Most of humans are usually covered with blankets, what sticks out gets bitten: head, shoulders, feet in my case.
They buzz because their wings beat with a certain frequency, the frequency is the buzz. They beat their wings with this frequency because that is the rythm they must beat their wings to fly at the speed they wish to fly under the given conditions (temperature, humidity, wind…). The buzz has advantages for them: it helps them locate mates of their own species. Male and female mosquitoes of the same species buzz at diffferent frequencies.
Depends totally on the species of mosquito. There are mosquitoes that breed in melting snowpools. There are mosquitoes that are active in the tropics. And everything in between,
I am a professional “mosquitologist”. Been researching mosquitoes for over 25 years.
You’re correct; they’re buzzing your ears because they’re attracted to the CO2 you’re exhaling.
The buzzing is a product of their wings. They use it to communicate - for example for the mosquito Aedes aegypti, when mating the female and male match wingbeat harmonic frequencies. If the male doesn’t do this correctly the female won’t mate.
The wingbeat frequencies are very species-specific. There is actually a cell phone app that can identify mosquitoes based on their wingbeat frequencies.
And with a really cool avatar to boot. Yes, all hail our new Mosquito Overlord longstanding expert.
A question about this if I may …
This suggests to me that a “typical” mosquito doesn’t eat very frequently. As in one feeding can sustain them for a day or more. That seems counterintuitive on a scaling basis, which suggests maybe I’m barking up the wrong tree here.
So: are they frequent eaters, grazers really, or more like the proverbial “pig in the python” where a good meal lasts a long time for them.
The itch is entirely due to the immune system. The lifespan of mosquito proteins would not be that long. They are foreign proteins. The itch can stay longer. Read an article on the immune system to see how all the parts work. Histamine I labeled as key. The other link explained it but here is this one.Histamine - Wikipedia
The avatar is a picture I took a long time ago of a transgenic Anopheles mosquito expressing green fluorescent protein (GFP) in it’s eyes.
Mosquitoes generally feed on plant sugars for their day to day nutritional needs. They’ll feed on these every day. (most) Female mosquitoes take blood for reproduction. They’ll generally blood feed every 3-4 days and drop a batch of eggs after each bloodmeal.
Some mosquitoes don’t feed on sugar, they feed on blood exclusively for their nutrition and reproduction. These guys will bloodfeed more frequently (every other day or so). This can make them more efficient at transmitting pathogens. The lab I was trained in studied this phenomenon extensively.
