Wasp

A wasp, not a bee

Yellowjackets are often confused with honey bees because of similar coloration, but they’re easy to distinguish:

• Yellowjackets have a smooth, hairless, glossy body and narrow waist.
• Honey bees have a fuzzy body and a thicker, more rounded abdomen.
• Yellowjackets are predators and scavengers; honey bees are pollen and nectar specialists.
• Yellowjackets can sting repeatedly; honey bees die after a single sting (their barbed sting is left behind).

Many home “bee problems” are actually yellowjackets, which deserves consideration before any extermination — honey bees are crucial pollinators and several species are imperiled.

A dual-personality calendar

Yellowjacket behavior changes dramatically through the summer:

• Spring/early summer — colonies are small, workers focus on raising larvae. The larvae feed on chewed-up insects (caterpillars, flies, spiders, even other wasps), making yellowjackets excellent garden pest controllers.
• Late summer/fall — larval production ends, but adult workers persist. They switch to seeking carbohydrates — fallen fruit, picnic food, sweet drinks — and become much more aggressive about defending these sources. The autumn picnic ruined by yellowjackets is the predictable annual phenomenon.

A nest that lasts one season

Almost all yellowjacket nests are annual, founded by a single overwintered queen each spring. She builds a starter nest, lays eggs, and raises the first batch of workers, then transitions to egg-laying full-time as the colony scales up. By August, a healthy nest may contain several thousand workers.

When fall arrives, the colony rears new queens and males that mate. Mated queens overwinter alone (the only survivors); the original colony — workers, original queen, males — dies off when temperatures drop. The next spring, surviving queens start new nests, often nowhere near the previous year’s location.

Underground nests

Yellowjackets typically nest underground, often in abandoned rodent burrows. The hidden, ground-level nest is one reason they cause so many stings — lawn mowers, weed whackers, and dogs disturbing nests trigger immediate, swarming defense from hundreds of workers.

A different kind of social

Yellowjackets are eusocial — like ants, bees, and termites. The colony has reproductive division of labor (queens reproduce; workers don’t), cooperative care of young, and overlapping generations. Eusociality has independently evolved fewer than 10 times in the history of life on Earth, but each occurrence has produced spectacular ecological success.

Asian giant hornet

A relative of yellowjackets in the family Vespidae — the Asian giant hornet (Vespa mandarinia, the so-called “murder hornet”) — was detected in Washington State in 2019 and made global news. Asian giant hornets are not yellowjackets but distantly related; they’re the largest hornets in the world (5 cm long), specialize in attacking honey bee colonies, and can deliver dangerous stings. Eradication efforts in North America are ongoing.