If it kills the host, it’s not a very successful parasite, or it’s a parasitoid as only one other commenter has picked up. It’s not in parasites’ interest to kill their hosts, it usually happens when they infect a non-preferred host and the system responds differently, like the pork tapeworm Taenia solium which doesn’t kill pigs but can be lethal in humans.

Those are some mercurial tempera…tures

They’re generally called vinegar flies, and they don’t infest fresh fruit like fruit flies do when they lay their eggs in fruit.

Varroa mite has entered the chat

Reverse irredentism! Now what about historically German lands? From the Maas to the Memel…

Sounds like you have hard water