Mosquitoes, belonging to the family Culicidae, are small insects that measure an average of just over 6 mm in length and weigh approximately 2.5 milligrams. Their bodies are divided into three main parts: the head, thorax, and abdomen, each with specialized structures and functions.
The head of a mosquito houses essential sensory equipment that enables the insect to locate and feed on humans and other animals. This section provides an overview of the key structures found in the mosquito’s head.
Mosquitoes possess two large compound eyes, each covered with multiple tiny lenses called ommatidia. These ommatidia allow mosquitoes to detect even the slightest movement. Additionally, mosquitoes have ocelli, simple photosensitive eyes on top of their heads that can detect variations in light.
Long feathery organs called antennae project forward from the mosquito’s head. These antennae contain sensitive receptors that can detect carbon dioxide in human breath from distances of over 100 feet. The maxillary palp, located between the antennae, picks up the odor of ocentol and other chemicals released in human sweat.
The proboscis, a long serrated mouthpart, is situated between the antennae and is used to pierce the skin and draw blood. The proboscis contains two tubes: one that injects saliva containing an anticoagulant and mild painkiller, and another that extracts blood from the host.
The thorax, which connects to the head, can be considered the mosquito’s torso. It is the attachment point for a pair of wings, a pair of halteres (small wing-like organs used for steering), and six legs. The legs are tipped with tiny claws that help mosquitoes cling to surfaces.
The abdomen extends from the thorax and functions as the mosquito’s stomach and respiratory system.
Small openings called spiracles are located along both sides of the abdomen. These openings allow mosquitoes to draw in air for respiration. In female mosquitoes, the abdomen also stores ingested blood and houses eggs. A nerve in the abdomen signals when it is full of blood.
Entomologists, or scientists who study insects, use subtle differences in the shape and coloration of mosquitoes’ abdomens, as well as variations in the length of the maxillary palp and wings, to identify different mosquito species.