Most multicellular organisms including mosquitoes and other insects need a nervous system in order to coordinate all the functions that are essential to their lives including reproduction, digestion and maintenance of energy production. Though significantly different from primate brains, mosquitoes do have brains which help them do all this and more.
As expected, the mosquito brains are usually not very large. Unlike human beings and other primates, they also have collections of nerve fiber bodies called ganglia in other parts of their bodies. These ganglia perform secondary functions to free up the main brain to carry out the important tasks which are essential to the life of the mosquito.
In terms of functionality, mosquito brains are not significantly dissimilar to human brains. They have been studied to regulate executive level behaviors and can also learn and memorize them as well. Mosquito brains are located dorsally and usually comprise three lobes of clustered neurons. These lobes process sensory information and each lobe is responsible for different functions.
The first lobe is responsible for vision and light control to aid the mosquito to navigate to hosts or flowers for pollination. The middle lobes, also known as deutocerebrum, control the antennae. In this manner, they can collect environmental information such as humidity and temperature, detect odor particles and even tactile sensations. Lastly, the third lobe also known as the tritocerebrum integrates the information from the other two lobes, and also connects to the upper lip of the mosquito.
Though rudimentary compared to human brains, mosquito brains are sufficient for the feeding and reproduction of the mosquitoes, and also more or less protect them from predators.