It is as astonishing as it is sad to watch a ladybug turn into a zombie. Normally ladybugs are sophisticated and voracious predators. A single individual may devour several thousand aphids in a lifetime. To find a victim, it first waves its antennae to detect chemicals that plants release when they’re under attack by herbivorous insects. Once it has homed in on these signals, the ladybug switches its sensory scan to search for molecules released only by aphids. Then it creeps up and strikes, ripping the aphid apart with barbed mandibles.
Ladybugs are also well protected against most of their enemies. Their red-and-black dome, so adorable to the human eye, is actually a warning to would-be predators: You will regret this. When a bird or some other animal tries to attack, the ladybug bleeds poison from its leg joints. The attacker tastes the bitter blood and spits the ladybug out. Predators learn to read the red-and-black wing covers as a message to stay away.
A predator protected from other predators, the ladybug would seem to have the perfect insect life—were it not for wasps that lay their eggs inside its living body.