Crimson mosquitoes spawn seemingly out of nowhere in the overworld when it says they are only found in crimson nether forest biomes. I tried changing the spawnweight to an extremely high number to make the chance of them spawning impossible which worked for a bit, but reactivating a nether portal and encountering them again in the forests seems to make them spawn back in the overworld. Not sure what is happening with this. I am using Valhesia 3 for the modpack, which includes this mod.