In Iowa, spider wasps are ubiquitous yet mostly go unseen until one accidentally invites one inside. Spider wasps are slender insects with strong spiky legs, about 1/2 an inch in length. The wings are typically a smoky black or blue, whereas the body is usually dark. As the wasp flits across the ground in quest of food, it constantly jerks its wings. The female’s antennae are noticeable because they are coiled or curled.
What would you eat?
Insects known as spider wasps target just spiders as a food source. Different members of this species use a wide range of venoms and paralysing mechanisms, but most will sting spiders in just one or two spots to render them helpless. The spider wasp may drag, carry, or even fly the paralysed insect back to the nest. However, most spiders can live for weeks before succumbing to the emerging larva and dying a horrible death.
Where do you go to locate them?
Spider wasps can be found in various habitats, including cities, wooded areas, wetlands, and grassy plains. Australia is home to a wide variety of spider wasps.
In most cases, the spider wasps you see will be females building nests for their young. First, they use the large spines on their front legs to excavate a hole, and then they frantically look for a spider nearby, both on the ground and in the branches of trees. After paralysing the spider with a single blow, the wasp will drag it or carry it back to its underground home. The spider can be as big as a huntsman or funnel web and twice as heavy as the wasp. At the end of the tunnel, she creates a little chamber or cell where she lays an egg on the spider’s body and then closes it off. The spider’s egg hatches into a larva, which then feeds on the spider’s body and spins itself into a delicate silken cocoon within the cell. Not all spider wasps dig a hole for the spider to live in after stinging it and laying an egg on it. Some species of Spider Wasps prey on the spiders of other Spider Wasps to feed their larvae. The spider is left at the sting site, and the larva hatches and devours it.
It’s not uncommon to spot a spider wasp pulling a huntsman spider across the sand as it digs. Several species will bite the legs of big hairy spiders to make them more manageable. Still, others may sneak up on their prey and attack without being seen by anyone by using their scales to navigate spider webs. Upon touching down, spider wasps will often flap their wings and hop around. The wasp uses this behaviour to locate a potential spider meal in places like tree bark, crevices, and soil.