Wasps are capable of both biting and stinging, but these two actions serve entirely different purposes. The sting is the primary defense mechanism and the source of almost all human pain, involving the injection of complex venom. Biting, conversely, is a routine function related to the wasp’s daily life and rarely results in significant injury to a person.
The Primary Defense Mechanism: Stinging
The painful sting delivered by a wasp is an act of defense. This mechanism, found only in female wasps, evolved from the ovipositor, the organ used by many insects for egg-laying. The stinger is a hollow, needle-like structure that injects venom into a perceived threat, causing immediate, intense pain.
A critical anatomical feature of the wasp stinger is its generally barbless nature. This allows the wasp to easily withdraw the apparatus after use, unlike the barbed stinger of the honey bee. Because the wasp’s stinger remains intact, an agitated wasp can sting a person multiple times in quick succession.
The venom injected is a potent chemical cocktail of enzymes, peptides, and biogenic amines like histamine and serotonin. These compounds work together to break down cell membranes and stimulate nerve endings, causing immediate, sharp pain. While the venom deters threats to humans, many species of wasp use the neurotoxins to paralyze prey, such as spiders or caterpillars, ensuring a fresh meal for their developing larvae.
The Function of Biting
Biting is performed using the wasp’s mandibles, mouthparts adapted for chewing and grasping. These mandibles are used for a variety of non-defensive tasks related to the wasp’s ecological role and nest construction. For example, social wasps like yellow jackets scrape and chew wood fibers, mixing them with saliva to create the characteristic paper-pulp material used to build their nests.
Mandibles are also essential for procuring and preparing food for the colony’s growing larvae. Adult wasps use their jaws to capture and dismember other insects, cutting the prey into manageable pieces before feeding the protein-rich parts to the young. Solitary species may also use mandibles to excavate soil or manipulate mud for building specialized nests.
A wasp bite is typically a minor event, as the mandibles are not designed to penetrate thick skin for defense. If a wasp bites a human, it is usually a warning or a result of being trapped, resulting in a negligible pinch that rarely breaks the skin. The bite does not involve the injection of venom, which is stored and delivered exclusively through the stinger.
Immediate Aftermath and Response
Following a wasp sting, a person will experience sharp pain, redness, and localized swelling at the injection site. The first step in treatment is to clean the area with soap and water to prevent secondary infection. Applying a cold compress, such as an ice pack wrapped in a cloth for 15 to 20 minutes hourly, can help reduce swelling and dull the pain sensation.
Over-the-counter treatments, like oral antihistamines or pain relievers, can manage the localized itching and discomfort that may persist for a few hours or days. Since the wasp does not leave its stinger embedded, scraping the skin is unnecessary, but the area should still be inspected. Elevating the affected limb is advisable to help minimize swelling.
A small percentage of the population may experience a severe allergic reaction known as anaphylaxis, requiring immediate medical intervention. Symptoms often affect areas far from the sting site and can progress rapidly. Signs include difficulty breathing, wheezing, swelling of the face, lips, or throat, widespread hives, a rapid or weak pulse, or feelings of dizziness and fainting.