Written by Rachel Putnam, Kroening Nature Center Naturalist
There is a lot to enjoy outdoors in a Minnesota summer, but one less enjoyable part is having a wasp show up at a picnic or build its nest nearby. Indeed, these insects can deliver a painful sting if threatened or disturbed. It helps to know where to look for their nests. Bald-faced hornets collect wood fibers to build large, football-shaped paper nests that are often found hanging in trees, while yellowjackets have more rounded paper nests and may nest underground. Paper wasps use wood fibers to build a flat paper comb, and their nests are usually tucked under an overhang since they do not build a protective paper covering over their nest as hornets and yellowjackets do.
It may come as a surprise to learn that there are many species of wasps in Minnesota that never sting people. The tiniest wasps in Minnesota are just a millimeter long and parasitize nests of other bees and wasps. Another type of tiny wasp, called cynipids, are just a few millimeters long; we rarely see the wasps themselves, but you might be familiar with these wasps if you’ve ever seen weird-looking rounded growths on oak leaves or branches. These are galls, created by the plant when the wasp lays its eggs on the plant. There are many species of gall-making wasps, each specific to a particular type of plant, and each species makes a unique gall. The galls don’t typically cause much harm to the plant, and the young wasp has a safe place to grow and develop.
Not all wasps are yellow and black, either. Cuckoo wasps, for instance, are iridescent blue-green. Unable to sting, these small wasps are still fearsome – if you are a bee or wasp. Cuckoo wasps lay their eggs in bee and wasp nests and upon hatching, feed upon the bee or wasp larvae in the nest. Great black wasps are entirely dark with blueish iridescence on their wings. You might see them on flowers in the park as they hunt for grasshoppers and katydids.
Many wasps are beneficial to people because they feed on other insects that we consider pests. Wasps will kill caterpillars to feed to their young, and some of the largest wasps in Minnesota tackle even larger prey. Cicada killers are wasps that live up to their name by hunting and paralyzing cicadas, then dragging the cicadas to a burrow where the hatching wasp larvae will feed upon the cicadas. At almost two inches, these wasps look intimidating, but they are solitary and rarely bother people. If you’re lucky, you might get a glimpse of one of these helpful and non-aggressive wasps this summer.
Curious about what’s going on in the park this summer? Check out our upcoming programs offered at Kroening Nature Center in August (registration available online).
Drop-in Nature Art: Leaf Rubbing · Saturday, August 2, 11 a.m.-3 p.m. Free, all ages (no registration required). Collect leaves from around the park and use paper and crayons to make some leaf rubbings to bring home. Make them into your own tree ID guide booklet if desired!
Nature in the Park: Shells · Thursday, August 7, 10 -11 a.m. $9, ages 18+ (activity #21612). Explore along the banks of the Mississippi to look for shells. We’ll find both common species as well as rare and protected mussels. Compare and identify different species and learn more about the animals that left these shells behind.
Drop-in Nature: Prairie Exploration · Saturday, August 16, 11 a.m.-3 p.m. Free, all ages (no registration required). Drop by the nature center to check out a menu of self-guided activities focused on the prairie habitat. Activities include nature art, looking for critters, a scavenger hunt and focused observation. Try one or try them all!
Nature Art: Weaving with Plants · Saturday, August 23, 1:30-2:30 p.m. Free, all ages (activity # 17671). Take a walk to collect tall prairie grasses and flowers to use for art. Add your touch to a group art project and make a woven decoration to take home.
Drop-in Nature: Summer Sampler · Saturday, August 30, 11 a.m.-3 p.m. Free, all ages (no registration required). Drop by the nature center to check out a menu of self-guided activities including nature art, adventure hub kits, a scavenger hunt, and focused observation. Try one or try them all!