Family Lycaenidae includes the most extreme ant-mutualists — the 'large blue' (Phengaris arion) has larvae that are CARRIED INTO ANT NESTS and feed on ant larvae as obligate ant-nest parasitoids.
Female botflies catch mosquitoes in mid-air and glue eggs to their underside — turning the mosquito into an unwitting delivery courier. The strategy is called phoresy.
Tarantula hawks paralyze a tarantula with a single sting to a nerve cluster, then bury the still-living spider with an egg attached.
Cuckoo wasps lay eggs in other wasps' nests — the larva eats the host's stored food, sometimes the host egg too.
Female velvet ants are parasitoids — they invade other wasp/bee nests and lay eggs on the host pupae.
First-instar larvae are OBLIGATE PARASITES of SPIDER EGG SACS — actively search out spider egg sacs, burrow inside, consume developing spider eggs and spiderlings, pupate INSIDE the egg sac.
Larva CONSUMES THE ANT'S BRAIN AND HEAD MUSCLES — connective tissue weakens until the ANT'S HEAD FALLS OFF, decapitating the ant. Fly then PUPATES INSIDE THE DETACHED ANT HEAD CAPSULE.
