Why speculate? https://www.nea.gov.sg/corporate-functions/resources/researc...
TLDR for this link is that they release male mosquitoes carrying a bacteria called Wolbachia. So this only affects the one species of mosquito they're targeting: Aedes aegypti.
alt Hacker News
TLDR for this link is that they release male mosquitoes carrying a bacteria called Wolbachia. So this only affects the one species of mosquito they're targeting: Aedes aegypti.