by Matilda Willows

Created on: July 31, 2011

Both male and female mosquitoes get their main source of nutritional nourishment in the form of sugar, which is often from plant nectar. This is their main food source and how they get the energy they need to fly. So which mosquitoes are responsible for sucking blood?

Well, you’d never find a blood-sucking male mosquito, that’s for sure. It’s actually only the females that feast on the blood of humans and animals. Indeed, the females are those responsible for all those annoying mosquito bites, but why is this and why are they the only ones that engage in

hematophagy (drinking blood) and not the males?

The main reason the females are guilty of blood-sucking all comes down to the survival of her offspring and the maternal instinct. She doesn’t simply feed on blood for the fun of it, but rather because she needs it for her young. The female mosquitoes have this extra need for additional supplementary nutrition found in blood because it provides the needed protein and iron for her eggs to develop.

Female mosquitoes who suck blood are pregnant ones, and the blood they feed on is essential to be able to lay her eggs ready for hatching. Since it’s only the females that are able to lay eggs, and the males simply fertilize them, the females are the ones who need to feed their growing children.

These pregnant females select their blood victims in a number of ways. These can include: detecting carbon dioxide; certain body odors; heat; lactic acid; genetics and ‘sweet’ blood from food among other factors. They can also detect their preferred prey by a distance of up to 50 meters away.

When the female has chosen her blood source, she simply produces a type of saliva which is placed onto her victim’s skin, and which acts to stop the blood from clotting as well as acting as an anesthetic so she can sweetly and quietly feed on the blood to her stomach’s content, and without harming her victim through any sensation of pain. It's only after she has gone, that the salvia left behind causes irritation and upset.

Once the female has fed on the blood, she digests the blood, which usually takes from around 3-4 days and then is able to, lays her eggs. Whenever she has a new load of eggs to look after and lay, she will be on the search for a source of blood to do so.

Female mosquitoes suck on the blood of humans and animals that take their fancy for the simple reason of ensuring their offspring grow and develop. It is the protein and iron found in blood that are essential nutrients needed for their survival. Although male and female mosquitoes primarily feed on sweet plant nectar, it’s only when the female is pregnant that she needs to supplement her diet with blood.

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