Wasps are predatory insects belonging to the order Hymenoptera, making them close relatives of both bees and ants. They are known for their slender bodies and temperaments, which frequently bring them into conflict with humans. The perception that wasps are aggressive stems from behaviors rooted in their annual life cycle. To understand their inclination to sting, it is necessary to examine the motivations that drive their actions, which range from a search for food to the need for colony defense.
The Seasonal Shift in Temperament
The increase in wasp aggression observed in late summer and early fall is a consequence of a change in the colony’s nutritional economy. During the spring and early summer, worker wasps hunt protein, such as caterpillars, to feed the developing larvae in the nest. The larvae secrete a sugary, carbohydrate-rich saliva that the adult workers consume as their primary energy source. This system keeps the workers focused on their duties and generally away from human activities.
By the end of summer, the colony reaches its peak population, and the queen slows her egg-laying, concentrating instead on producing new reproductive queens. As the last of the larvae mature, the workers’ internal source of sugar diminishes, leaving a large population of adult foragers needing carbohydrates. These hungry workers become desperate scavengers, aggressively seeking external sources of sugar like soda, fruit, and garbage. This frantic search for an energy substitute is the main driver of the nuisance aggression people experience in August and September.
Instincts Driving Defensive Behavior
While late-season scavenging accounts for nuisance behavior, true aggression is driven by the instinct to protect the nest and the queen. Social species like yellow jackets and hornets will mount a coordinated defense when they perceive a threat to their colony. Their goal is to eliminate any danger to the next generation of queens and the nest structure.
Specific actions will provoke a defensive attack, including ground vibrations near a subterranean nest entrance, rapid movement like swatting, or trapping a wasp against the skin. When a wasp stings in defense, it releases a chemical alarm pheromone. This signals to other nearby wasps that the colony is under attack, potentially triggering a mass response.
How Wasps Differ From Bees
A biological difference between wasps and most honeybees is the structure of their stinging apparatus. Wasps possess a smooth stinger that allows them to withdraw the weapon easily and sting a target multiple times without suffering injury. This capability means a wasp is less hesitant to use its stinger. In contrast, the honeybee’s stinger is barbed, causing it to become lodged in the thick skin of a mammal, tearing away from the bee’s body and resulting in its death.
The difference in diet also contributes to a greater frequency of human-wasp encounters. Wasps are generalist predators and scavengers, hunting other insects for protein while also seeking sugary substances for energy. This broad diet frequently draws them to human environments, such as picnics and trash bins, which are rich in both protein and carbohydrates. Bees, on the other hand, are primarily herbivorous, collecting nectar and pollen from flowers, which limits their presence in areas of human outdoor dining.