Linked from
The 14 pages that link to Host specificity, each with the reason it gives.
ParasitismRelated: Host range determines where a parasite can persist and spread.
HostRelated: A parasite's host range determines which organisms can sustain its life cycle.
Parasitoid waspRelated: A wasp's host range shapes which populations it can attack.
BotflyRelated: Botfly species differ greatly in which mammals can support their larval development.
Cuckoo beeRelated: Cuckoo bee species vary in how narrowly they target host bees.