Mosquito Control > Mosquito larva

Mosquito larva


Mosquito larvaThe larvae or "wigglers" live in water and move with a motion which has given them their common name. The head and thorax are large and distinct, while the abdomen is slender, and projecting from next to the last segment of this section of the body is a respiratory tube which is usually rather long and near the end of which the breathing organs open by a sort of spiracle. When air is desired, the larva floats to the surface and projects the tip of the respiratory tube just above the water level, to renew its supply (Fig. 1).

The larvae have mouth-parts of the chewing type, and some are plant feeders. Most of them, however, are predacious, feeding on tiny water animals and even on other mosquito larvae, a pair of small brushes at the mouth being used to cause currents in the water and bring food within their reach. They molt four times and, after a varying length of time (a week or 10 days in many cases) in different species and at different seasons of the year, transform into pupae. These are quite different in appearance from the larvae, the head and thorax forming a large rounded mass, joined by a slender abdomen.

Differing from most insect pupae, the pupal mosquito is active, moving through the water by a curious tumbling end over end. On the top of the thorax in this stage are two breathing tubes (Fig. 2), and when air is desired the tips of these are pushed above the surface of the water. The animal swims by making use of a pair of leaf-like appendages at the end of the abdomen.

After a brief pupal stage, usually lasting only a few days, the animal comes to the surface of the water and a split of the pupal skin along the middle of the back of the thorax appears, through which the adult mosquito escapes, balancing itself on this skin until it is ready for flight. Of the many kinds of mosquitoes known, a small number are of particular importance aside from their habit of attacking man, being mosquito disease carriers.