It sounds like you want to take a calculated risk. I'm not convinced that this is a calculated risk -- it's an unbounded risk. What if it, for example, kills of pretty much all of the insects over a large part of the earth?
Risk management, on the other hand, is about determining risks that are reasonably likely, and figuring out contingencies and mitigation strategies.
In your opinion, is it reasonably likely that a fungi that is engineered to kill a specific species of insect (and only those carrying a specific disease) can somehow go out of control and end up killing all insects on the planet? In my opinion, it is not.
It's a form of concern-trolling: deep down inside you are against something, but don't want to say that openly, so instead you pretend to side with the proponents, but choose to play the role of "concerned citizen" and invent scary scenarios at the extreme ends of the probability spectrum, with the suggestion that "we should probably research this thing more before we try it!"
What is encouraged is taking actions that have well understood OR bounded risk.
By bringing up "concern-trolling", I am concerned you have given up the fight. By avoiding the direct argument and retreating to this supposed hidden argument, which is much easier to counter, there is not anything left to discuss. Tell me if I am misunderstanding.