Wasps, flies and moths are all natural predators of the ladybug and will attack it at different stages of its development from its larval state to, more rarely, its adult state. Many flies and wasps are parasites to the ladybug, using its body as a platform to raise and feed their young after laying eggs under the ladybug's exoskeleton by means of stingers or bodily invasion.
Wasps will attack and eat ladybug larvae because they are defenseless and rich in nutrients. They may also lay eggs within ladybug larvae so that their own larvae can feed on such a rich food source after hatching.
Moths will attack adult ladybugs and consume the soft parts of their body, leaving the exoskeleton behind. Ladybugs are especially vulnerable to large, aggressive moths which can approach silently and give ladybugs no chance to hide or deploy any defense mechanism before the moth has sighted them and struck.
Adult ladybugs have tough shells and can secrete a repulsive, toxic yellow substance which most predators dislike. These combined traits, along with the insect's propensity for playing dead, make them undesirable as adults to many of the predators which target them when they are small and as yet undeveloped.