Let's devote ourselves to protect the lives of mosquitoes・・・・・・That's not the case.
Originally, there is World Mosquito Day as an international day, not just in Japan.
Wikipedia explains:
Observed annually on 20 August, is a commemoration of British doctor Sir Ronald Ross's discovery in 1897 that female mosquitoes transmit malaria between humans.Ross is responsible for the annual observance, having declared shortly after his discovery that the day should be known as World Mosquito Day in the future.
The insect repellent I recommend is an herbal insect repellent.