Roaches!!
Mosquitos, I don't like them and they carry killing diseases to so many other species but DragonFly's depend on them as food; same with many species of birds.
My pick is Roaches!
There are a small handful of people that I've actually hated in my life, dealt with and have grown out of that hate. However, with regards to when I've hated those people I'd not ONCE wish upon them what I went through.
My mothers apartment when I was young was infested with Roaches. American version or whatever the smallest versions are. She was a pack rat with cloth and patterns all over the apartment ~ yet a slave driving clean freak (vacuum dishes, wood polishing tables/china cabinet; you get the idea) not the disgusting kind though.
Imagine moving the couch to vacuum and more than 30 roaches (adult/young) scurrying for a place to hide (Day or Night)! Imagine having to knock off your shoes, you jeans, your shirt/sweater or winter jacket BEFORE putting any on daily (paranoia sets in where you do this with your underwear - when out of the draw, then take them into the shower, then before you put them on IN the shower). Imagine having a preference AGAINST certain cereals: Sugar Crisp or many oat cereals - because they actually look TOO close to roach eggs if they where somehow burnt during production and found in your box [EVEN if freshly opened]. Imagine sleeping and in a deep sleep having a tickling sensation that you slap yourself or brush yourself on your arm, back, leg, or head ~ a few time ~ only to wakeup and seeing a roach running for cover that caused that tickle or itch! Or to find a road dead in your bed because you squished it while turning.
Imagine this all for the first 16yrs of your life and the other 4yrs after still having a weird itch when you sleep (long after you've moved out) just cause of years of hideous memories ... flesh memories. 30 mins showers JUST to ensure every inch of your body is CLEAN!
Imagine some of your WORST life experiences being:
* Told by female parent that lived next door telling you in the elevator that THEIR moving because of too many roaches coming from your apartment!
* spending your lunch money (that you got ONLY 1 time a month/3mths $5-10) on locating the largest and most flammable spray can of hair spray or other so that you can target BURN roaches when you lifted the coach, or moved furniture!!
* Growing up as a kid under 10 no allowed to have friends over, and then
* at 15 having 20 kids over your apartment (6/7 being guys invited to bring drinks to a party a few floors down from yours in the same apartment). Then the girls come up, so many kids sitting on your couch, you in the kitchen mixing drinks into bottles/jug, then come out in the dinning section JUST to discover a BIG BAD poppa roach that was BRAVE enough to crawl on the wall in midday over the heads of the girls that LIVE in your 'hood, RICH/Pretty girls. Those girls that where standing by the door with what should've been a CLEAR view over to the wall where that ROACH was being distracted by a friend (whom I questioned was even 1 twice before) doing the block. 1 girl FINALLY sees it and lets out a shrill scream that I've YET to hear in ANY gore/horror movie that has ever released in the past 30years. The only save for that, a buddy brushes it off the wall, kills it on the floor, and another buddy says "WHAT! NOOOOOO! You killed daffy!! That was like the best pet!!"
Bewildered girls where so terrified and confused; not knowing what to think left with the guys and drinks ~ I show up to the party 1hr later and only those guys recalled what happened ~ drinking DOES do the mind good sometimes.
Yes I would KILL all existence of Roaches! No species depend on them as primary food or exclusive food, no parasite or symbiot rely's on them and they are disgusting. Either that or the ability to selectively erase these from my memory and my sisters.
I'm SO GLAD that all those boxes where cleared out just before I was 16 (well most; only 3 remained which where thrown out), and no longer is a problem for my mom & sister when they moved years ago to their Condo.
I wouldn't wish this on ANY enemy.