When you imagine mosquitoes, you probably recall the many bad things they cause; they bite, irritate your skin, are bloodsuckers, sleep disruptors, pests, and transmit deadly diseases. But do you know that not all mosquitoes suck your blood? Only females do. Despite them being so small, will you be able to differentiate females from male mosquitoes? Yes! And here are a few simple ways to know them.
If you are to have a closer look at mosquitoes, the one with hairier or have more flagella on their antennae are male mosquitoes. They appear bushier to the naked eyes. The flagella help in mosquitoes hearing, especially when they are looking for females mosquitoes. Also, male mosquitoes are generally smaller.
Since male mosquitoes do not need human blood, they will typically avoid human contact. Female mosquitoes are the ones that can produce annoying buzz sounds, and they are the bloodsuckers. They have more sensitive flagella, which have odor receptors able to detect blood sources from their target. There is a need for female mosquitoes to suck blood to have the necessary nutrition to produce eggs.
Mosquitoes can survive and live well without extracting blood as they can feed on sucking sugary substances such as the nectars of flowers. However, some species of female mosquitoes will not lay eggs if they don’t find vertebrates to suck blood.
A nectar diet might be energetic for them, but it won’t provide enough proteins (amino acids) or other substances needed for oogenesis or the production or development of eggs. In an experiment, a right combination of amino acids injected into a female mosquito produced eggs without blood ingestion.
Like other insects that undergo metamorphosis, mosquitoes have two stages of life; larval and the adult stage. Adult life is dependent on the larval stage. Mosquito larvae, strictly aquatic, colonize areas that are sometimes poor in nutrients: the water that remains in an abandoned pot in a plot of urban land or the rainwater of a puddle. They cope with multiplying in these ephemeral environments and transforming into an adult mosquito in record time using the amino acids and available nutrients very effectively. But, after the metamorphosis, adults will no longer have supplies for the production of eggs. This process requires the right amount of those substances, and it will need to get them on its own: for example, sucking blood from a vertebrate that has it in abundance. It is a demonstration of how evolution succeeds in generating organisms capable of adapting to almost any circumstance. To compensate for the limitations of larval development, it produced the female mosquito, a machine specializing in the difficult task of making use of the blood.
Why are mosquito bites painful and irritating? If you compare the amount of blood extracted from a blood test than when mosquitoes bite you, the former will get more blood from you. But why are mosquito bites bother us so much? It is because the female mosquito stinger is technically perfected that it is more subtle than any medical needle.
Some studies assumed that it could even serve as a model for designing a less annoying system of injection than the current one, which would improve the lives of those who have to undergo continuous hypodermic injections. Mosquito bites sting because female mosquitoes not only pierce the skin and extract blood from the capillaries with its subtle stinger but also inject saliva before they start sucking. That intrusion of foreign molecules contained in the mosquito saliva causes an itchy reaction in the body and, sometimes, it can even produce severe reactions in allergic people or when one suffers many bites.
The injection of saliva is needed to counteract the normal defensive reactions of an organism facing a wound. That is to say, the break of blood vessels: firstly, vasoconstriction (a decrease in blood flow) and, in second place, blood clotting, processes that would hinder the mosquito’s blood extraction. Female mosquitoes must inject a refined mixture of substances with their saliva to counteract the mechanisms of the attacked organism. Only female mosquitoes contain this mixture in saliva. There are studies in detail due to its potentiality in pharmaceutical use.
Mosquitoes’ ability to transmit diseases has caused more deaths than all deaths from wars combined. That is why researchers are looking into an incredibly exciting world of mosquitoes and understanding what lies behind a single female mosquito bite.