Wasps get a bad rap, mostly because of aggressive yellow jackets. Most wasp species are solitary and so have no need to defend their colony. Wasps play an essential role in yards and natural ecosystems by controlling pests and pollinating flowers.
Unlike their cousins the bees that eat pollen, wasps eat other insects, like caterpillars, flies, and beetles. They are predators or parasitoids of a variety of pest insects that are over populating. Adult wasps hunt other insects to feed their protein-hungry larvae and are important parts of the food-web. Many parasitoid wasps overwinter within their hosts in leaf litter or on senesced plant stems. Parasitoid wasps can’t even sting because that body part has evolved into an ovipositor in order to place their eggs inside the host.
A wasp many of us are familiar with is the mud daubers. These parasitic wasps make mud tubes under decks that look like pipe organs by collecting mud one mouthful at a time. They stuff these tubes with spiders that they have pearlized but are still living so they don’t spoil. Once a tube has enough spiders, the wasp lays an egg and seals up the tube. The baby wasp hatches and eats its spiders and then emerges from the tube to start the process over.
Cicada killer wasps are large, big enough to carry a cicada. The cicada killers nest underground, sometimes a bunch of them will nest near each other in a lawn. When there is a cicada boom year the wasps collect the cicadas and bring them down into their nests. Watching a cicada killer at work is impressive, I recommend it.
I love to see the giant shinny blue wasps called the great black wasp. They can be 1.5 inches long! They are black with a blue iridescence and seem almost tame when visiting a flower so I can get some good photos. This is a great wasp because it pollinates milkweed and can eat up to 16 grasshoppers a day.
Wasps spend a lot of their time pollinating flowers. The much-adored butterflies are actually not as good at pollinating as wasps are. Wasps eat nectar and in return transfer pollen between the plants they visit. Orchids lure wasps to their flowers by mimicking the scent and pattern of female wasps, but instead of a date the guy gets covered in pollen. If you want to grow native orchids, you are going to need to provide habitat for its wasp.