Are fogging and mosquito patches effective?

Patches and wristbands are scented with citronella, peppermint or similar oils, which are not as effective as repellents with Deet and picaridin.
Patches and wristbands are scented with citronella, peppermint or similar oils, which are not as effective as repellents with Deet and picaridin.TNP FILE PHOTO

Q How effective is thermal fogging?

A Thermal fogging is conducted using a device that vaporises a special insecticide, spreading it over a large area. The chemical kills adult mosquitoes, and it works really well in this department.

However, it has its limitations.

The fog remains in the air for only about 10 minutes. Mosquitoes that fly into the area after the fog has dispersed will not be affected as much.

Fogging just a single area might also result in chasing mosquitoes to another location. That is why it has to be properly planned.

As thermal fogging uses insecticide, it could also harm other insects such as moths and flies. But it is safe for humans and unlikely to harm animals such as birds and cats.

Importantly, fogging has to be complemented with public efforts to prevent mosquitoes from breeding, by eliminating stagnant water, and not littering, for instance.

Q Are mosquito repellent patches and wristbands effective in protecting against mosquito bites?

A Patches and wristbands are scented with citronella, peppermint or similar oils, which are natural ingredients that help prevent mosquitoes from smelling humans.

But such oils are not as effective as repellents which contain Deet, or diethyltoluamide, and picaridin.

The higher the concentration of Deet and picaridin, the longer the anti-mosquito effect lasts.

Wristbands, which work by diffusing the natural repellents in the air, are also not as effective.

According to studies, a wristband may stop mosquitoes from landing on the hand or wrist, but they could still bite higher up on the arm.

Samantha Boh

A version of this article appeared in the print edition of The Straits Times on September 06, 2016, with the headline 'Are fogging and mosquito patches effective?'. Print Edition | Subscribe