They are known to steal your blood, violate your personal space and leave you helpless with softball-sized itchy lumps. If there is anything that definitely unites humans – it is our all-out hatred for mosquitoes.
That mosquitoes are bad news is recorded in the annals of history. They’ve been around for more than a hundred million years and are known to kill more people in a day than sharks do in a century. Malaria alone takes credit for 6 million deaths every decade. They also spread various diseases such as dengue, West Nile virus, chikungunya, Zika, and a host of other deadly diseases. World Mosquito Day was established in 1897 to mark the discovery of the link between mosquitoes and malaria transmission by Sir Ronald Ross. The day is not a celebration of the painful little insect, but aimed at raising awareness about the causes of malaria, its prevention and to enable fundraising for research into the cure of malaria. It’s also a day which marks the groundbreaking work of Sir Ross and scientists after him
In what can be termed as a never-ending war between man and the winged foe, here are some of the ways humans have tried to eliminate mosquitoes.
A special train called the “Mosquito Terminator” was introduced in Delhi to spray anti-larval chemicals along the tracks to control mosquito breeding. These power sprayers, designed to eliminate not only the larvae but also neutralise mosquitoes, also meant to provide relief to people living along railway tracks.
Carbon-dioxide mosquito traps
The modus operandi of a mosquito trap is enticing. Mosquitoes are attracted to carbon dioxide – which is how they locate us. Now that science has established why and how mosquitoes are attracted to humans more than other creatures, the lure used by these traps is simple – to mimic human respiratory patterns. Mosquitoes are tricked to believe these traps are “potential targets”. Just as a mosquito flies near the trap, it is sucked in, dehydrated and killed.
Smartphones designed to repel mosquitoes
LG unveiled the K7i recently. It’s a smartphone with a unique selling point – its built-in Mosquito Away technology. The technology in the phone uses ultrasonic noise that is inaudible to humans, but not to mosquitoes, to keep them at bay.
Genetically modified mosquitoes
The Aedes aegypti mosquito, which is responsible for spreading diseases which include dengue, chikungunya, yellow fever and Zika is the main target of this project. This project involves genetically sterilising male mosquitoes and then releasing them into the wild, where they will only create male offspring when they reproduce. With only males left, the population will slowly dwindle and die out.
In another project, Oxitec, a biotech firm, injects the male sperm cells of the mosquito with a lethal gene. When the mosquito is released into the wild and it mates with a female, the passing of the transgene will kill the offspring.
Alphabet’s Verily has completed a mosquito suppression trial using Sterile Insect Technique which involved rearing non-biting sterilised male mosquitoes, while removing the biting females. Scientists needed to raise 20 million mosquitoes to produce 3 million males. Verily’s technology helped quicken the sex sorting with much higher accuracy. The results of the trial was that 80 per cent of the target mosquito species, Aedes aegypti, was suppressed along Queensland’s Cassowary Coast.
Scientists have been working on RNA-based insecticides to kill female Aedes aegypti by promoting cell suicide. This basically creates a clear instruction for the mosquito – telling it to go kill itself.
Sir Ronald Ross would be proud to see that over a century later, humans are still as focused – if not more so – on eradicating mosquitoes from the planet. It’s a different matter that we’ve failed to do so. But in honour of World Mosquito Day, it’s only fair that we acknowledge those scientists who are fighting the good fight. May their breed – the scientists, not the mosquitoes – grow stronger.