Vector and Pest Management: Mosquitoes in Malaysia.

In Malaysia there are about 434 species and subspecies of mosquitoes belonging to 20 genera. However, only the genera Anopheles, Aedes , Culex and Mansonia are of medical importance.

Four types of Mosquitoes in Malaysia

Anopheles

Anopheles also can serve as the vectors for canine heartworm Dirofilaria immitis, the filariasis-causing species Wuchereria bancrofti and Brugia malayi, and viruses such as one that causes O'nyong'nyong fever. The other disease such as malaria

Aedes

Members of the Aedes genus are known vectors for numerous viral infections. Viruses that cause dengue fever, yellow fever, West Nile fever, chikungunya, and eastern equine encephalitis.

Culex

Vectors of important diseases, such as West Nile virus, filariasis, Japanese encephalitis, St. Louis encephalitis and avian malaria.

Mansonia

Mansonia mosquitoes are big, black or brown mosquitoes with sparkling on their wings and legs. Transmit various arboviruses, including Venezuelan equine encephalitis.Mansonioides transmit several arboviruses, Brugian filariasis. Mansonia uniformis, is a vector of Wuchereria bancrofti.

Life cycle:

The life cycle undergoes four stages: egg, larva, pupa and adult. Most adult mosquitoes mate shortly after emergence. Female mosquitoes lay about 30-300 eggs at one time. Eggs are black or brown in color and 1mm or less. In most culinices, the eggs are elongate or oval in shape and laid on the water surface in a raft, but eggs of Mansonia are cylinder and pointed apically and laid in a sticky mass on the underside of aquatic plants. Adedes do not lay their eggs on the water surface, but laid singly above the water line on a moist substrate and can withstand desiccation for months. Eggs of anophelines are boat-shaped and laid singly on the surface of the water.

With a few exceptions, a female mosquito must bite and take blood meal for egg. After a blood meal the mosquito’s abdomen becomes dilated and bright red in color, later becoming a darker red. 

As the blood is digested, eggs are formed and the abdomen becomes whitish posterioly and dark red anteriorly . At this stage the mosquito is half gravid. When all the blood is finally digested and the eggs are fully formed , the mosquito is said to be gravid and ready to lay its eggs.

After eggs-laying or ovipostion the female mosquitoes ready for anther blood meal. The process of blood feeding , digestion and egg formation followed by oviposition is called the gonotropic cycle. In the tropics it takes about 2-3 days, but in colder temperate countries it takes between 7 -14 days.

Did you know?

• Mosquitoes have been around for more than 30 million years.
• Mosquitoes have been honing their skills, experts at finding people to bite. 
• Mosquitoes have a battery of sensors designed to track their prey.
• Mosquitoes can sense carbon dioxide and lactic acid up to 100 feet (36 meters) away.
• Have visual sensor, if you are wearing clothing that contrasts with the background, and especially if you move while wearing that clothing, mosquitoes can see you and zero in on you.
• Have heat sensors which is mosquitoes can detect heat, so they can find warm-blooded mammals and birds very easily once they get close enough.

Mosquito control method.

Here are some tips to consider when trying to avoid mosquito bites:

First of all, no vaccine is available yet for the prevention of dengue infection and there are no specific drugs for its treatment. The other way from environment management which is have to involves any change that prevents or minimizes vector breeding and hence reduces human-vector contact.

Another tips is empty water from containers such as flower pots, birdbaths, pet water dishes, cans, gutters, tires and buckets regularly to disrupt the mosquito breeding cycle. Keep windows and door screens in good working order to prevent mosquitoes from entering your home. If possible, wear long-sleeved shirts and long pants while outdoors, consider staying indoors early in the morning and evening when mosquitoes are most active. 

Next, maintain your swimming pool to prevent mosquito breeding, and report abandoned pools to your local health department. Use mosquito netting over infants carriers when infants are outdoors. Consider using an insect repellent, be sure to follow the label directions for applying the repellent.