Distinguish the male insect from the female; the former has feathery feelers, and has mouth parts unsuited for biting.
How many kinds of mosquitoes have you seen? Direct attention to the kind which causes the spread of malaria. It is recognized by its habit of standing with its body pointing at right angles to the surface on which its feet are placed or, in other words, it appears to stand on its head.
THE DEVELOPMENT
Describe the egg raft.
Observe the wigglers (hatched in about a day); the divisions of the body of the wigglers; position of the wigglers when at rest. Observe that the tail end is upward. Lead the pupils to perceive that this is the means of getting air.
Observe the rapid movement toward the bottom when disturbed; the means of causing this movement; the change into the large-headed pupæ—a change which takes place about ten days after hatching; the almost motionless character of the pupæ; the change from the pupæ forms into the adult—a change which takes place at about the fourth day of pupæ life.
Put some mosquito larvæ (wigglers) into the fish aquarium. Are mosquitoes of any use? The wigglers are the food on which some young fishes live. Young bass and trout feed upon them.
Put some kerosene on the surface of a jar in which there are mosquito larvæ. Describe a method of destroying mosquitoes.
The teacher tells about the mosquito as the cause of the spread of malaria. From the fact that the eggs hatch on stagnant water, deduce a benefit arising from the draining of land.