This week for Flora and Fauna Friday we have a collection of communally living insects who don’t always make the best neighbors, the Umbrella Paper Wasps of subfamily Polistinae.
Paper Wasps are a clade of wasps that build nests out of “paper”. They chew on dry, dead wood and stems to collect wood pulp, chew it up into a paste, and then meticulously construct an intricate nest one mouthful at a time. Today I’m focusing on the Umbrella Paper Wasps who build upside-down, open-face nests on the limbs of shrubs, in the cavities of trees, or the underside of under-used lawn furniture. Paper Wasps are all eusocial insects, meaning there is a “queen” who founds a colony and gives birth to subservient, infertile workers who then go about managing, maintaining, and expanding the nest. Umbrella Paper Wasp colonies are fairly small compared to other eusocial insects, like ants and honeybees, and usually clock in between 1 to 4 dozen individuals. Colonies only last a year, with the queen’s fertile offspring overwintering to found new colonies the next spring.
Paper Wasp nests are a common sight under eaves and porches, and other inconvenient places throughout South Carolina. We have several species of this subfamily common throughout the state but two which are particularly common here around Edisto that I’d like to shine a light on: the Ringed Paper Wasp (Polistes annularis) and the Mexican Paper Wasp (Mischocyttarus mexicanus cubicola). These two species are the two you’re most likely to encounter taking up shop in the crook of your awning or underside of your rocking chair. The Ringed Paper Wasp, or Jack Spaniard Wasp, is found throughout the Southeast. It’s about an inch and a half long with black wings, a black abdomen, brick-red body, yellow feet, and a yellow ring around the waist. They’re big for a Paper Wasp and, in my experience, they’re far more aggressive than other species. Most Umbrella Paper Wasps are fairly docile and it takes a concerted effort, or really poor luck, to get them to rouse. However to me it seems like Ringed Paper Wasps are always itching for a fight. All female Umbrella Paper Wasps can sting and I can tell you from experience that the sting of the Ringed Paper Wasp is particularly painfully. Said species’ sting usually resulting in a white-hot searing pain, throbbing soreness, and light inflammation at the site of envenomation. Conversely, the Mexican Paper Wasp is very docile and they tend to just stare passive-aggressively at you from their nest unless you get dangerously close. This species is common on the extreme coast of South Carolina, down into the coastal plain of the lower Southern states. The Mexican Paper Wasp is petite at about an inch in length. Their coloration is a brick-red base on much of the body with prolific rings and markings of lemon-yellow, and black undertones on the upper legs and thorax. Their small abdomen and elongated waist sets them apart from smaller members of the Polistes genus.
Paper Wasps have an interesting diet and, as a result, an irreplaceable role in our ecosystems that many overlook. Paper Wasps are actually a very important pollinator. A significant portion of their diet comes from nectar, which they sip directly from wildflowers, pollinating them in the process. They also incidentally pollinate flowers while collecting their primary food source, caterpillars. Paper Wasps patrol flower, leaf, and stem of all manner of wildflower, grass, tree, and shrub on the hunt for caterpillars. Captured caterpillars are either eaten by the wasp that found it or brought back to the nest to feed their sisters and carnivorous larvae. The ability of Paper Wasps to hunt the caterpillars of innumerable moth and caterpillars is second to none. This provides an invaluable ecosystem service in the form of pest control for farmers and gardeners and, in the strictly natural setting, is a critical link in the natural checks and balances for population control of certain plants and moths. Without the Paper Wasps, certain moths and butterflies would multiply unchecked, defoliating and/or killing many plant species across an entire ecosystem, decreasing plant diversity at best or totaling destabilizing certain fragile ecosystems at worst. Of course, Paper Wasps don’t do all the work. Caterpillars make up a majority of quite a number of species’ diets but the seasonal consistency and non-specific targeting of Paper Wasps puts them in another league.
