The Yellowjacket wasp, belonging to the genus Vespula, is a member of the family Vespidae, under the order Hymenoptera, which also includes ants, bees, and other types of wasps. These insects are classified as social wasps, meaning they live in colonies with a caste system including a queen, workers, and drones. There are numerous species of yellowjackets, primarily found in the Vespula genus, although some closely related genera share similar behavior and appearance.
Yellowjackets are relatively small, compact wasps, typically measuring between 10 and 16 millimeters in length. They are easily identified by their bold black and yellow coloration, giving them a striking, wasp-like appearance that often causes confusion with bees. Unlike bees, however, they have a slender waist, smooth bodies, and folded wings when at rest. Yellowjackets also possess a smooth stinger that allows them to sting repeatedly, which they use to defend themselves and their colonies aggressively.
These wasps are sometimes referred to by other names such as “meat bees” or “ground hornets”, depending on their behavior or nesting habits. The term “meat bee” is especially common in areas where yellowjackets aggressively scavenge meat from outdoor gatherings, barbecues, and picnics. Despite the colloquial use of “bee” in some of these names, they are wasps, not true bees, and their behavior is distinctively more predatory and territorial.
Yellowjackets are found widely throughout North America, Europe, and parts of Asia, with many species particularly common in temperate regions. They thrive in both natural and urban settings, often nesting underground, in wall cavities, or inside hollow trees. Their ability to adapt to human-altered environments makes them frequent visitors to gardens, parks, and trash bins.
They typically build papery nests from chewed wood fibers mixed with saliva, creating structures that may be hidden underground or visible hanging from eaves or tree branches. Colonies are usually seasonal, with only the queen surviving winter by entering diapause (a form of hibernation). Each spring, a new colony begins when the queen lays her first batch of eggs and raises the initial group of workers.
Yellowjackets have several natural predators, including birds such as bee-eaters, robins, and sparrows, as well as spiders, dragonflies, mammals, and other wasps. Despite their potent stings, they are vulnerable to predation, especially late in the season when colonies weaken and resources become scarce.
As adults, yellowjackets have a varied diet. They feed on nectar, fruit juices, sugary substances, and other insect prey, which they often chew and feed to their larvae. While larvae require protein-rich food such as caterpillars, flies, and meat scraps, the adults often consume carbohydrates to fuel their energy-intensive flying behavior. This scavenging and hunting habit makes them beneficial to ecosystems as both pollinators and pest controllers, even though their aggression makes them unwelcome guests at human gatherings.
Life cycle and habits of Yellowjacket Wasp (Vespula spp.)
The life cycle of the Yellowjacket wasp (Vespula spp.) follows a typical pattern for social wasps, consisting of four main stages: egg, larva, pupa, and adult. The entire process begins in early spring when a fertilized queen, who has overwintered in a sheltered place, emerges from hibernation and searches for a suitable nesting site. Once she finds a location—often underground, in hollow logs, or within wall cavities—she begins building a small nest using chewed wood pulp, forming paper-like cells.
The queen lays the first eggs into these initial cells, and after several days, they hatch into larvae. These larvae are fed chewed-up insects and protein-rich material by the queen. After going through several molts, the larvae spin cocoons and enter the pupal stage, eventually emerging as worker wasps—the sterile female caste. These workers take over the duties of nest expansion, foraging, and larval care, allowing the queen to focus solely on laying eggs for the rest of the season.
As the colony grows throughout summer, it can reach a population of thousands of workers, depending on the species and conditions. The workers are responsible for defending the nest, foraging for food, and maintaining the nest structure. Yellowjackets become increasingly aggressive and noticeable in late summer and early fall when food sources become scarce, often scavenging for sugary drinks, ripe fruits, and meat at human gatherings.
By late summer, the queen starts producing new reproductive individuals—males (drones) and fertile females (future queens). These reproductive wasps leave the nest to mate in flight, after which the males die, and the fertilized females seek sheltered spots like soil crevices, woodpiles, or leaf litter to overwinter. Meanwhile, the old queen and the rest of the colony begin to die off as the weather cools.
Yellowjackets are highly organized, with a clear division of labor and communication through pheromones and body language. They are diurnal, being most active during the day, and are known for their territorial behavior near the nest. If disturbed, they can swarm in large numbers and deliver repeated stings, which makes them a serious threat when nests are located near homes or recreational areas.
These wasps exhibit scavenging and predatory habits, feeding on a mix of protein and sugar sources. Workers capture other insects to feed the developing larvae, while adults consume nectar, honeydew, and sugary liquids for energy. This dual diet makes them important pollinators and natural pest controllers, though their aggressive nature can make them hazardous to people and pets when disturbed.
The colony does not survive winter; only the newly mated queens enter diapause and restart the cycle the following spring. Each year, a new nest is built from scratch, as old nests are never reused. This annual cycle ensures that populations remain under natural control, though favorable conditions can lead to significant surges in yellowjacket numbers during peak seasons.