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Is a mosquito a parasite?

I am trying to understand if a mosquito is a parasite. An internet search on this seems to provide conflicting results, however, most sources say that no it is not. Another issue is most internet sources are focused on the parasites mosquitoes transmit.

Here are some things I would like help understanding.

I realize that not every part of the mosquito life cycle requires that it take a blood meal. Essentially it can eat other things and live physically away from the host. This seems somewhat similar to a tick, which is considered a parasite, because technically a tick can live off the host as well when it drops off. I do understand the tick can only survive from a blood meal though. The mosquito does depend on blood from a host to complete it's life cycle so wouldn't this make it a parasite?

Next, when a mosquito takes a blood meal wouldn't this differ from traditional predator/prey relationship in that the mosquito is not killing its prey, but rather living off of it?


I thought the answer to this
I thought the answer to this question would be more subjective. On the parasite blog I run when I ask the question what is a parasite my answer is "I don't know." : )

Parasitologists vs. Entomologists
The confusion stems from a historical quirk. Entomology departments have historically had a major focus on agriculture, with strong departments linked to land-grant institutions. In contrast, the strong Parasitology departments have historically been linked to medical schools with a focus on human health concerns in the tropics. These same medical schools also had strong departments of microbiology, covering bacterial and viral infections, leaving the diseases caused by protozoa, worms, and arthropods to the parasitologists. Given the medical focus of these departments, only those species linked to human disease were studied. In terms of arthropods, those species that feed on vertebrate blood and tissue are traditionally covered by parasitologists. So, classically, parasites were considered to be protozoa, worms, and arthropods that cause harm to people or other vertebrates as part of their life cycle. It is certainly an artificial grouping of organisms.

Because of this clearly artificial designation, the remaining departments of parasitology (there aren’t many left) have broadened their reach, now covering any life form that causes disease in vertebrates, particularly those from tropical regions. It is still artificial because the focus remains on disease in vertebrates, and the requirement that it provide benefit to the organism causing the damage has been mostly ignored (e.g. zoonotic viral infections). For my parasitology degree, I took classes in virology, microbiology, protozoology, and helminthology, and these classes only covered species associated with disease in vertebrates. I was able to get credit for the entomology requirement because this was my undergraduate degree. At this point, organisms are grouped together under the label of “parasite” based on the purposes of the person doing the grouping. Because the term (as used in the medical community) has always been artificial, I think it is okay to group organisms in whatever way is useful.

In contrast with the work done in parasitology departments, entomology departments have looked at parasites in a very different way. Insect ecologists try to figure out the secrets of life, with the goal being to understand the fundamental rules that govern behavior. A fundamental rule is one that applies in a wide variety of situations, and so with this in mind, parasitism is defined as an interaction between two organisms that increases the fitness one (the parasite) and decreases the fitness of the other (the host) without reducing the fitness all the way down to 0 (e.g. death). There are numerous ways to sub-classify parasitic relationships, but by keeping this very broad definition, ecologists can compare different types of parasitic relationships to see what is the same and what is different, helping them to uncover fundamental rules. The ecologist’s definition seems more natural, but it is certainly too broad to be useful for public health purposes. I like Blaine’s idea that you can define what is a parasite based on your personal preference.

i would have to say...
non-symbiotic parasite or grazer.

How about:
Parasitism is a type of symbiosis (a close relationship between differing species). What most people think of as "symbiosis" is mutualism, where benefits are received by all participants. Commensalism is where one benefits, while the other receives none and is not harmed. Parasitism in the where one benefits at the cost of the other.

Grazing and browsing identify methods of herbivory. Foraging could include gathering of any type of resource.

Not quite sure if hemiparasitism could be applied to opportunistic blood feeding.

hey all
I am a parasitologist (and to some degree entomologist) with the CDC's Dept of Parasitic Diseases. When adding arthropods of medical importance to the DPDx website, we were deciding what is and is not considered a 'parasite'.

We decided to leave parasites as those that reside on the host (fleas, lice, hard ticks, etc) or in close proximity (such as bed bugs and soft ticks). We decided that biting flies were outside the realm of what is classifided as a 'parasite.'

Nevertheless, you should not dismiss the importance of mosquitoes and other blood-suckign flies from a public health perspective.

In the long run, it seems to be a matter of personal preference.

How about "Non-grass grazer" ...
See discussion here. Sounds about right, especially since I don't like any of the alternatives like egg nutrient provisioners!

A simple definition:
A parasite organism consumes less than one individual of another species (this would include the other species resources (food stores) or even biological by-products (skin flakes). As with all things biological, the gray areas are up for discussion. Also, the parasite species is obligated to use the other species for survival and the survival of it's own species. In this form of symbiosis, a parasite does not provide any benefits to the host.

Dunno! Good Question...
...and are mosquitoes really all that different from vampire bats when it comes to what they do with humans? Both animals sneak in, they grab a blood meal, and then they go. I'd call that the actions of a predator myself, albeit a tiny one.

Some of our local mosquitoes can transmit parasites--heartworm--but that only earns them the label 'disease vectors' in addition to the more usual 'pests' or 'vermin' or 'those #@$% bloodsuckers'.

It all hinges on definitions
Browsing through several Wikipedia articles didn't clear things up much. The way one article described it, "grazing" would be the most likely choice, since it was described as a form of predation that didn't kill the prey, and that both plants and animals could be described as prey. The article on grazing itself treated it as strictly a herbivore eating plants.

The mosquito-blood-source relationship certainly is reminiscent of grazing, but broadening "prey" to include plants and "grazing" to include animals seems to me like forcing traditional words to mean things for which new words should be coined.

can't help adding to the confusion
the wonderful Mullen & Durden's Handbuch(1) consistently applies the term 'parasite' to pathogens only (though some are known to kill the host), not to the blood-sucking vectors

Probably all pathogens
could be considered parasitic, not all parasitism results in a disease condition (pathology). It might be easier to restrict the term "parasite" to organisms that live in very close proximity to the host for at least one active life stage. Free roaming mosquitos or tabanids, maybe not. Hippoboscids, Bat flies, or Bot flies for sure. For real confusion try delving into various parasitic strategies involving social insects (E.O.Wilson's Sociobiology sets the stage quite well).

proximity is the key
Wow, a good discussion. I think Kerry has the right idea--it is the proximity/and immobility that makes the parasite. Look at the etymology (Wiktionary--parasite):
From Latin parasitus < Greek παράσιτος (parasitos), “‘person who eats at the table of another’”) < noun use of adjective meaning "feeding beside," < παρα- (para-), “‘beside’”) + σίτος (sitos), “‘food’”).

A mosquito, horsefly, or vampire bat does not remain attached to its host for an extended period of time, so they are not parasites. A tick does, so it is a parasite. The odd thing is that there is no common biological term for what the "grazers" do--it is like a sub-lethal predation. Perhaps it should be called "kinder, gentler predation"!

Parasites don't kill their prey...
under normal circumstances (the occasional exception doesn't matter as much as the overall pattern). The term "parasitoid" was invented to cover those cases where the host is typically killed.

Male mosquito are definitely not parasites, and I believe females only need blood meals for reproduction, rather than survival. Beyond what I mentioned above, I don't know the criteria for deciding whether an organism is a parasite or not.

If it helps any . . .
Tapeworms are considered parasites, and they similarly live off a host without killing it.

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