Eaten alive
Some wasps lay eggs on spiders' abdomens. When the wasp larva hatches, it gradually eats the spider from the outside in. Photo: M Gray © Australian Museum.
Laying in supplies: Mud dauber wasps sting and paralyse spiders. They seal them inside mud nests so there is fresh food for their young. Photo: © Densey Clyne.
Fly larvae have eaten the Bolas Spider's eggs and then pupated inside the spider's egg sac. Some of the adult flies have just emerged from their pupal cases. Photo: M Gray © Australian Museum.
Spiders are often the target of hunting wasps seeking food for their young. Some wasps lay eggs onto the spider's abdomen. When the wasp larva hatches, it gradually eats the spider from the outside in, often starting near the spider's waist (pedicel), where the cuticle is softer and it is securely out of reach of the spider legs.
Mud dauber wasps sting and paralyse spiders, especially small orb weavers. They construct cell-like mud nests and pack them with one or several spiders before laying an egg on a paralysed victim and sealing up the mud cell. When the wasp's egg hatches there is plenty of fresh spider food for the hungry larva.
Spider eggs provide a highly nutritious source of food for the larvae of many species of wasps, flies and mantispid lacewings. Wasps and flies use their long ovipositers to penetrate into the egg sac and lay their eggs among those of the spider. Mantispids lay their eggs on bark; when the larvae hatch out, they disperse into bark crevices seeking and entering spider egg sacs.
