Giant parasitic wasps from hell with a taste for human hosts.
I've always considered parasitic wasps to be creepy as hell with the way they constantly twitch when hunting for prey. Imagining one big enough to prefer humans as hosts gave me the twitchies. The author said 3 inches, but I was picturing something closer to 10.
These are also a bit smarter than your average wasp. Capable of revenge if one of them or a larva is killed. Thanks to modern travel, they have spread everywhere. Can the humans fight back ans survive?