About Mosquito Bites and How to Avoid Them 

Mosquitoes transmit diseases that kill more than a million people worldwide each year. The female mosquito needs a blood meal when she is forming eggs. Mosquitoes find the blood they need because they can detect carbon dioxide from our breath, perspiration and lactic acid from our skin and infrared heat from our bodies.

Having found their source of blood the mosquitoes land on the skin and immediately probe for a blood vessel with their hypodermic needle-like mouthparts. You will probably not notice this as the mouthparts are so fine and the mosquito injects saliva that contains anti-coagulant and anaesthetic. Once found, the blood is ingested and filtered to keep the blood cells and the water is excreted. This filtering means the mosquito can obtain more than 5 times as much nutrient from a feed as if they took the whole blood.

If you have been bitten by mosquitoes it is likely that they have resulted in an itchy red bump. The first mosquito bite you had probably didn’t cause this as your immune system was not yet primed to react to the foreign proteins in the mosquito saliva. But in subsequent bites, your immune system is primed to recognise these proteins and attack them with histamines. The histamines make cells in the blood vessels spread apart, allowing fluids to leak out into the skin and cause a bump. The bump triggers other receptors and leads to the itching sensation. This is why antihistamine creams and tablets can help reduce itching and swelling.

The injection of saliva can carry disease-causing organisms including malaria, dengue fever, West Nile virus and Zika. Thankfully only dengue fever is present in New Zealand and it usually only affects travellers from other Pacific regions.

However, mosquito bites in New Zealand are unpleasant and annoying. So here are some tips to help avoid bites:

Indoors

• Fit fly screens on windows and doors.
• Use insect sprays such as Insect Guard when mosquitoes are around.
• Install Insect Guard or NO Mosquitoes plug-in mosquito repellers.
• Use mosquito coils at dusk.
• Use a mosquito net over your bed at night. You can spray this with NO Spiders Total Protection for added protection.
• If available, use air conditioning to cool the room.

Outdoors

• Use insect repellent; repellents containing high levels of DEET are most effective.
• Wear protective clothing such as long-sleeved shirts, long pants and hats. Clothing can be treated with repellent.
• Avoid places where mosquitoes are most active, such as swampy areas.
• Check for and drain or treat any pooled stagnant water in the area.
• Mosquitoes do not breed in grass or shrubbery, but adults frequently rest on these surfaces during daylight hours and spraying with NO Bugs Super or PLANThealth Spectrum will help control them.
• When camping both warm and cool LED lights attract about half as many insects as yellow compact fluorescent lights which are often recommended for camping as they attract fewer insects. Many LED bulbs emit almost no UV light, and they also put off almost no heat.

See here for more information on how to get rid of mosquitoes and avoid bites.

David Brittain
Kiwicare