Ara Damansara

Keep the mozzies away with mosquito nets and window nets.

The Aedes mosquito.

CONTRARY to popular belief that the Aedes mosquitoes come out only at dusk to bite, they are at it throughout the day, although they are most active during dawn and dusk.

Although one may have clean surroundings at home, many people get bitten while they’re away from their homes. The roadside stall, the never-fumigated office and the park are places that many get bitten at.

And compared with the outskirts, dengue seems to be most prevalent in urban areas.

According to Ridzuan Ismail, director of R&D and Entomology Research Centre, Fumakilla Malaysia Berhad, urbanites suffer most from this mosquito due to the nature of the mosquitoes itself.
“These mosquitoes are short-distance flyers and can only fly a distance of up to 50 to 100 metres. The more dense the population is in an urban area, the easier it becomes for the mosquitoes to fly around in the neighbourhood and bite people,” he explained.

Coupled with the fact that there are more construction sites and uninhabited houses in urban areas, he stressed, these places attract the mosquitoes to breed and infect people.

To ensure a mosquito-free home, we need to constantly check the surroundings of our house for any containers where water can remain stagnant or where drainage is clogged.

According to Ridzuan, it’s best to do a thorough check and clean-up once a week. Scrub and dry all possible water-clogging sites such as rain gutters, flower pots, empty cans and even in between big-leafed plants.

“Scrubbing is important because the Aedes egg can live without water for up to six months. As such, only scrubbing will destroy the egg and prevent it from hatching,” he stressed.

He also encourages the use of household insecticides to ensure that the home surroundings are free from mosquitoes.

“Household insecticides fall under a Class 4 classification, which means that they are least hazardous to humans,” he added. Adult mosquitoes should be targeted using an aerosol spray.

“It is recommended that mosquito coils be placed at the doorstep to prevent invading mosquitoes from flying into your home as it forms an invisible shield at the entrance. Similarly, mosquito liquid or mosquito mats use inside the home provides a continuous, ashless and smokeless protection against mosquitoes,” he added.

As it’s a tough fight against getting bitten, Ridzuan says there are ways to prevent mosquito bites. Topping the list, of course, is the use of insect repellents.

“When repellent lotion is applied onto the skin, it acts as a shield, keeping the mosquito away from the skin. A repellent lotion with Icaridin, an active ingredient recognised by the World Health Organisation as one of the most effective insect repellents for human use, works best to repel mosquitoes.

The evaporation of repellent lotion Icaridin will interfere with the mosquitoe’s olfactory system and renders the human skin as unacceptable to the mosquito,” he explains.

The non-greasy lotion is easy to apply, and allows the skin to breathe.

It also doubles as a skin moisturiser and has a good skin-feel factor.

Most repellent creams and sprays use the conventional active ingredient Diethyl Meta-Toluamide (Deet) which, although is as effective, tends to plasticise any plastic parts (for example, spectacles) that come into contact with it. Deet, he adds, also feels sticky on the skin and hence does not give that good skin-feel factor.

Natural extracts like citronella and eucalyptus, however, are said to have very limited efficacy. “If one were to compare the performance of Icaridin with citronella, the former can repel mosquitoes for at least six hours after application, while the latter has only a 40-50 per cent repellency rate at the first hour,” Ridzuan adds.

Besides repellent lotions, he says, one should also avoid wearing dark-coloured clothes as the Aedes mosquito is attracted to such colours, especially black and red.

10 things you should know:

1. Aedes mosquitoes prefer black and red over other colours.
2. Aedes mosquitoes are short-distance flyers — they fly up to 50 to 100 metres only. Most mosquitoes remain within a 1.61km radius of their breeding site.
3. Only female Aedes mosquitoes bite as they need the protein in blood to develop their eggs.
4. On average, an Aedes mosquito can live up to a month. A female Aedes mosquito can reproduce up to four times within its life span.
5. Aedes mosquitoes will lay an average of 300 eggs each time. The eggs need only seven days to become an adult mosquitoes upon contact with water.
6. Aedes eggs need just a teaspoon of water to hatch. The eggs can lie dormant in dry conditions for up to about six months.
7. A mosquito has two pairs of wings. Mosquitoes flap them to retain the moisture level in their bodies.
8. Mosquitoes locate blood hosts by scent, sight and heat. From 30 metres away, mosquitoes can smell your scent from the carbon dioxide you exhale. Mosquitoes can also sense your body heat and prefer a certain body temperature. Hence, certain people are more prone to mosquito bites.
9. Mosquitoes eat anything! Adult mosquitoes feed on flower nectar and decaying matter for flight energy. The larvae are filter feeders of organic particulates.
10. Mosquitoes have poor eyesight. They can’t see you until they are 10 metres away. When they are three metres away, they use extremely sensitive thermal receptors to locate blood near the surface of the skin.