Google life sciences will release 10 million mosquitoes into California in order to reduce the mosquitoes related diseases.
The mosquitoes released will be males and will be sterile. Male mosquitoes doesn't bite neither carries malerial viruses.
The aim is for the released male mosquitoes to mate with female mosquitoes because the sterilized mosquitoes will destroy the eggs produced by female mosquitoes.
Female Mosquitoes tend to mate only once while Males will continue to mate until they die. Females can produce up to 500 eggs. So if a sterile male mate, the female will no longer mate other male and the eggs(lots of eggs) won't develop; Thus reducing the population of mosquito eggs that will develop into an adult. Then the sterile male will do its business with another female; reducing the number of females in which the non-sterile males can mate. All of this will reduce the population and not eradicate.
I hope you understand.