Beyond the Sting Wasps: There is Something to Love

Our fear and loathing of wasps is both self-induced, and a product of external sources of misinformation. When we equate “wasp” with a stinging, social insect like a yellowjacket, hornet, or paper wasp, we ignore the 90% of wasps that lead solitary lives, and most of which do not sting. Far from the villains they are made out to be, wasps are pollinators of flowers, scavengers of dead animals, and indispensable allies in the control of agricultural and garden pests.

(Above) A male "tarantula hawk" wasp on milkweed flowers in El Paso County.

Wasps range from gargantuan “tarantula hawks” and cicada killers, both of which occur in Colorado, to fairyflies, nearly microscopic wasps that could, it is claimed, fly through the eye of a needle. Wasps are usually colorful, clad in black and white, yellow, orange, or red. Still others are vividly metallic green, blue, even ruby red or violet. Wasps symbolize the warrior spirit, female empowerment, and mastery of flight (though females of many species, like velvet ants, are wingless).

What good are wasps? Like bees, wasps are important pollinators. Do you like figs? Thank the hundreds of species of miniscule fig wasps, family Agaonidae. They are the only organisms that pollinate figs. Here in Colorado, pollen wasps in the genus Pseudomasaris are obligate pollinators of beardstongue (Penstemon spp.). Elsewhere on the planet, several orchid species have evolved to resemble female wasps in order to dupe the male insects into trying to mate with them. This “pseudocopulation” fertilizes the flower, but is a complete failure for the poor male wasp.

Economic interests would prefer that we see wasps as enemies, such that we can be sold products to kill them. The irony is that most wasps, left alone, kill pest species that are far worse. Paper wasps chew up caterpillars that would otherwise decimate your garden. Tiny braconid wasps lay eggs in aphids, turning them into “mummies” that incubate the next generation of braconids.

The very qualities that have made wasps a raging success in nature are also what draw our ire. They are maddeningly efficient at exploiting our every human weakness. Yellowjackets that scavenge the leftover victims of predators see no difference between a coyote’s abandoned kill and your plate of brisket at the barbecue. Our architecture, with roof overhangs and recessed window frames, mimics cliff faces, rock ledges, and crevices where mud daubers, paper wasps, and some yellowjackets build their nests. We destroy their usual habitats, then get angry when they take advantage of us. Female grass-carrier wasps in the genus Isodontia are now using the tracks of windows and sliding doors for their nests since natural cavities in dead trees have become scarce.

Yes, there are wasps that do damage, or appear to. The fluffy growths on your roses are initiated by the Mossy Rose Gall wasp. Other cynipid wasps create galls on oaks. Despite their grotesque or inflammatory appearance, galls made by wasps rarely do the plant harm. Galls simply serve as impregnable housing and food chambers for the larval wasp(s).

(At right) A female Western Cicada Killer wasp from Pueblo County.

Sawflies are primitive, non-stinging wasps that, as caterpillar-like larvae, feed on trees, shrubs, and other plants. Meanwhile, trees can fall victim to sawfly relatives, the horntail wood wasps. Horntails mostly attack trees weakened by fire, drought, other insects, and similar stressors. Several species have been introduced accidentally from overseas, and are fast becoming forest pests.

Oh, about horntails and those wasps with long, whip-like “tails” or spear-like appendages on their rear end. Those are not stingers. They are egg-laying organs called ovipositors. Ironically, the sting is derived from the ovipositor in the evolutionary sense, and a true sting is a short, retractable organ attached to venom glands. Of those species that sting, only females do so.

How do we live with wasps? Some people with hypersensitive immune systems overreact to stings, and face life-threatening consequences as a result. Get yourself tested to see if you are among this minority. The rest of us can practice tolerance. If you did not notice that paper wasp nest until it was full of wasps, then it is still not a problem. The wasps are tolerating you already, you can return the favor. In temperate climates, wasp nests are deserted in late autumn and almost never re-used.

Practice safe cookouts. Serve beverages in clear containers. Adult wasps crave sweet liquids, so will crawl into cans and dark bottles to get to them. Drinking in a wasp can be a potentially dangerous scenario for anyone.

(Above) A female Blue Mud Dauber wasp carrying a paralyzed, young black widow spider, El Paso County.

Underground nests of yellowjackets can be a hazard. Before mowing or using any equipment that causes vibration, tour your yard to make sure a nest is not located anywhere. Should you find one, flag it, and keep away until the end of fall when the wasps will have abandoned it. Many solitary wasps nest underground, too, sometimes in large numbers that make it appear they are social. Be patient, their activities usually last a month at most. Unless you grab a solitary wasp, or step on one in bare feet, it is not going to sting.

Realize that many insects you think are wasps are actually other insects. An absurd number of fly species, plus some moths, beetles, true bugs, and other harmless insects, mimic wasps in order to get a free pass from predators.

Eric R. Eaton is principal author of the Kaufman Field Guide to Insects of North America and writes the blog “Bug Eric.” Learn more in his new book, Wasps: The Astonishing Diversity of a Misunderstood Insect, Princeton University Press (2021).