Mosquitoes in Hawaii (Everything You Need To Know)

Mosquitoes in Hawaii

Are there mosquitoes in Hawaii? Well if you were asking this question in the 1800s, before European explorers arrived, the answer would have been “no”. Since then, unfortunately, mosquitoes have made a home on every one of the islands of Hawaii. They were probably first introduced to the island in 1826, when a whaling ship dumped a barrel of dirty bilge water on the island. The bilge water carried a few mosquitoes, who quickly bred in Hawaii’s warm, tropical climate. This was the start of the mosquito problem for Hawaii.

Are There Many Mosquitoes in Hawaii?

Though not as numerous as their relatives on the continent, some places in Hawaii have exceptionally high concentrations of mosquitoes. The most common species is known as Aedes aegypti  – the Yellow Fever Mosquito. This and one other are the only types that carry diseases affecting humans. 

Aedes aegypti, the Yellow Fever Mosquito
Aedes aegypti, the Yellow Fever Mosquito

How Long Have Mosquitoes Been Around?

These creatures are one of the oldest known species on the planet and have been around for an estimated 78 million years. Humans, by comparison, have only lived on Earth for about 100,000 years. Mosquitoes have had plenty of time to evolve alongside humans, and there are specific breeds of mosquito that will only feed on human blood.

What Problems Do Mosquitoes in Hawaii Cause?

Worldwide, diseases resulting from mosquito bites kill over one million humans per year, with malaria, zika, chikungunya and dengue fever being the main culprits. In 2017 there were thirteen reported cases of Zika on the island – a disease that can cause birth defects for those who have been infected. In 2015 there was an outbreak of dengue and earlier, in 2014, there were twenty-two cases of Chikungunya, which causes joint pain and fever. Luckily malaria, the biggest killer, has never been reported on any of the islands of Hawaii.

Apart from inflicting pain on humans, the mosquitoes are also playing havoc with the birds that are native to the island. One type of mosquito, called Culex quinquefasciatus, carries avian malaria. Since mosquitoes were never supposed to inhabit Hawaii, the island’s birds never developed an immunity to malaria.  

Over half of all the bird species of Hawaii have become extinct since the mosquito invasion, and nearly every surviving native bird is listed as threatened or endangered. Once, Hawaii had almost sixty species of bird native to the island forests. Now, only seventeen remain.

A mosquito bites the eye of a Hawaiian Honeycreeper bird
A mosquito bites the eye of a Hawaiian Honeycreeper bird. | Photo Credit: Jack Jeffrey

Why Do Mosquitoes Need My Blood?

When a female mosquito is close to laying her eggs, she needs to locate a source of food to feed her young. Human blood is full of proteins and amino acids, which makes it the perfect prenatal supplement. (BTW, it’s only the females that take your blood, and only when they’re pregnant. At other times, they’re happy to get their sustenance from plant nectar,  just like the males.) When it becomes time to give birth, the female lays her eggs in nearby water, and anchors the egg sac to flora that below the surface. 

Recently, scientists at Rothamsted Research in the UK discovered that some people produce chemicals that smell bad to mosquitoes. These people, therefore, have a natural defence to being bitten – the rest of us need insect-repellant.

When they feed (ie when they start to take your blood), mosquitoes inject saliva into the area around the bite. This works as an anticoagulant, which prevents your blood from clotting. Whilst this is good for the mosquito – because without it her proboscis may become clogged by your blood – it also triggers your anti-immune system, which reacts by causing the welts.

What Are The Signs of a Mosquito Bite?

If you’re bitten, a small red sore will appear in the targeted area which will become very itchy. Some people experience itching for 10 minutes, while others can’t stop scratching for days. 

The Southern House Mosquito carries avian malaria
The Southern House Mosquito carries avian malaria, and has wiped out many Hawaiian bird species

What Should I Do If I Get Bitten by a Mosquito?

Firstly, don’t panic! Here are a few first-aid tips:

  • Don’t scratch! As difficult as it is to avoid the temptation, scratching tends to make welts worse. If you can get to a chemist buy an antihistamine cream, such as Benadryl, and apply it as advised. 
  • If you can’t get to a pharmacy, wrap some ice in a towel and apply the icepack to the affected area for 10 minutes every hour. Cold temperatures and ice can reduce inflammation, and the cold also numbs the skin, which gives immediate relief from the welt.
  • Grab an onion! The juice from an onion contains a natural anti-fungal component that can ease the itching and help to reduce the infection. Cut a slice from the onion – any type will do -and apply it directly to the bite for no longer than 10 minutes, then rinse the area. And yes, it really works!

If symptoms worsen, consult a doctor immediately. Most hospitals are very used to dealing with mosquito bites, and they have all the treatments readily available. 

How Do I Avoid Mosquito Bites?

  • Avoid areas of still water. These areas are perfect for breeding, and so the highest concentrations will be around stagnant water pools and similar areas.
  • Avoid Hawaii’s rainy season (November to March). With more rainfall, there are more areas of stagnant water.
  • If you know you’re allergic to mosquito bites, always cover up before heading outside. Wear clothing that covers all your skin, such a thin long-sleeve shirt and light pants. Pay particular attention to your calves and the back of your neck, as these are high on the mosquito’s hit list.
  • Spend a lot of time at the beach! The faster winds that play around the coastal areas will help by driving mosquitoes away from you.
  • Time of day also has an effect on the mosquito’s trips into town – they’re particularly active in the early morning and evening. So avoid early mornings – which shouldn’t be hard – and stay out ’til late!

Is Anything Being Done?

Mosquitoes were around long before humans turned up, so they’ve had years to come up with defences against most things that we throw at them. However, a few initiatives are underway. 

The Sterile Insect Technique (SIT) is being used to catch and sterilise male mosquitoes, who are then released back into the wild. When the sterile males mate, the females produce no offspring. Without reproduction a species cannot survive, so it’s hoped that this method will eventually see a large reduction in Hawaii’s mosquito population. Google’s parent company, Alphabet, has a start-up in California called Verily that’s working on eradicating mosquito-borne diseases using a similar method.

Verily: one of the companies investigating mosquito control.
Verily: a company owned by Google who are investigating mosquito control. | Photo Credit: Alphabet

Another plan is to infiltrate the population with infected mosquitoes, carrying a disease that’s deadly to their own species but not harmful to any other wildlife. 

Hawaiian researchers are confident that these techniques will mean Hawaii can be once again mosquito-free, as it was back in the 1820s. Let’s wish them every success!

Until then, when you venture outside make sure to take sensible precautions, and always know how to get in touch with a hospital or a doctor. 

In Closing…

Hawaii is a beautiful part of the world – we know it really well and we just know you’ll have a great vacation. Just make sure the mozzies don’t bug you too much! [That was a terrible pun! Please delete it. Ed] 

If you’re looking for a few fresh ideas on what to do in Hawaii, why not check out our guide. Or if you’re into hiking, we have a few great recommendations. For our other Hawaii guides, just type the word ‘Hawaii’ into our search box and hit return. There’s a few surprises waiting!

We love to hear from people who’ve used our guides, so if you’ve got any questions about Hawaii or just want to chat, please get in touch with us. We love to help, and we love to talk!