Well, you see, what I did is search for the specific mosquito from the quoted text and found a link to a species of spider who's primary food source is the very same mosquito being discussed.

So either the scientist isn't very good at the google or just doesn't like "vampire spiders" and is lying about there being no predators for this mosquito. Whichever way you look at it this is the person you're trusting to release genetically modified organisms into the wild.