Well, in 279 hours of playing this game I've died a total of five times. Three were from being an idiot and jumping down from too high while building. One was to boss number 5 and one to a two star berserker. This would suggest that these insects you mention have indeed not been the cause of death to every player.

I personally found them to be the least dangerous enemy in the entire game, since all they require you to do is pay attention and either one shot them with a bow, or one shot them with a parry and smack.