MOSQUITOES
- The Anopheles mosquito
- The Culex mosquito.
- The Aedes mosquito.
The Anopheles mosquito:
This mosquito rests with its body at an angle to the resting surface and it has silent flight.
The male mosquito feeds on plant juice but the female must first have a meal of blood before laying eggs.
The eggs of an anopheles mosquito are scattered in water and they have aerofloats.
The larvae rest under the surface of the water parallel to the water surface.
The anopheles mosquito carries a protozoan called plasmodium that causes malaria fever.
Symptoms of malaria fever include (high body temperature), headache, vomiting, joint pains, general weakness, convulsions in children and miscarriages in the pregnant.
The Culex mosquito:
This mosquito rests with its body parallel to the resting surface and it whines during flight.
The eggs of a culex mosquito are laid in smart rafts and the larvae rest at an angle to the surface of the water.
The Culex mosquito carries a nematode called a filaria worm that causes elephantiasis.
The filaria worms block the lymph vessels resulting in swollen legs and feet.
The Aedes mosquito:
This mosquito resembles the Culex but its abdomen is stripped and thus it is also called the tiger mosquito.
The Aedes mosquito carries a virus that causes yellow fever.
Yellow fever is fatal disease that causes high temperature and internal bleeding leading to yellow urine and yellow eyes - a condition called jaundice.
There is a restriction of movement of people moving in and out of yellow fever areas like West Africa and South America.
Inoculation of visitors going to yellow fever areas and plane sprays are carried out.
Life cycle of mosquitoes:
- After mating, the adult female lays eggs in stagnant water.
- The eggs hatch after 4 days into an active larva called a wriggler.
- The larva has brushes for trapping food.
- Two weeks later the larva changes into a pupa which is fairly active since it comes to the surface to breathe.
- After three weeks, an adult with wings emerges and flies away.
- Male mosquitoes have tufted antennae unlike the female.
Means of controlling mosquito diseases:
- Killing the mosquito for example using insecticide.
- Avoiding the mosquito for example using mosquito nets.
- Interfering with the life cycle of the mosquito for example by draining breeding places or by destruction of larvae.
- Killing or preventing the pathogens i.e. disease-causing germs.