They're out there. You can't see them yet through the lazy wisps of barbecue smoke, but they've arrived, loitering near the grill like a street gang, waiting to crash the cookout.
Yellow jackets. Striped terrors bred to spoil parties. Brutally efficient hunters whose repeated stings can kill a horse. Meat bees, as they're called in California. What's a Labor Day picnic without them?
Many a family outing has been marred by yellow jackets hovering over a bologna sandwich. They pounce on a soda the moment the can is opened. These are the sounds of summer: Pop. Fizz. Buzz. Slap. Sting.
The Sting is coming soon, to a picnic table near you.
Perhaps no other insect evokes such fear and loathing as the yellow jacket. Ironically, no other creature is as undeserving of its reputation.
The truth is, yellow jackets are indefatigable workers, caring guardians and deft predators. Reputation aside, they don't care about man unless they are threatened. It's that bologna, not your body, they crave.
Yellow jackets rarely sting while away from the nest. But it's hard to sit still when one lands on your hand.
"Yellow jackets were not put on this earth to terrorize people," says Al Greene, an entomologist for the federal government in Washington. "The cartoons have it all wrong. Yellow jackets don't put on their goggles and come down from the sky after you, stinger first."
Despite their pushy demeanor, the insects have no beef with picnickers, says Mr. Greene.
"If you're eating a sandwich, they don't care about you. They've come by to check out those yummy smells."
Routinely, the yellow jacket preys on a more mundane menu of soft-bodied insects such as flies, moths, mosquitoes and caterpillars. Cicadas are a gourmet treat. Yellow jackets will even attack grasshoppers, discarding the inedible parts. Scientists have found mounds of grasshopper legs piled neatly by the entrance to the nest. Yellow jackets keep a tidy house.
The "Top Gun" in the world of flying insects, the yellow jacket can deftly pluck a spider from its web in midair. Totally dedicated to family, it will literally wear out its wings in an effort to feed and care for the young.
The yellow jacket is programmed to kill for its brood. It is a formidable flying nanny, half Mary Poppins, half Terminator. Crippled yellow jackets have even been known to limp on foot from the nest in search of prey.
When not stalking flies and other pesky insects, yellow jackets feed on nectar and help to pollinate flowers.
But the yellow jacket's critical role in the food chain is overshadowed by its skirmishes with man, particularly in late summer when the insects seem to become cantankerous junk food addicts. They swarm angrily around dumpsters, swimming pools and snowball stands.
The reason? The old yellow jacket queen is dying, the children are grown and the colony is crumbling. The adults have no one to feed or tuck in at night. So the Waltons of the insect world become a flying Addams Family.
Until then, however, their behavior is exemplary.
"Yellow jackets have gotten a bum rap," says Mr. Greene. "They are supreme predators, and one of the most important natural biological control agents. They are better than birds at reducing the pest population. But birds are fluffy and bright. Yellow jackets are icky and sting. And someone who has just gone into shock from a yellow jacket sting is going to turn a deaf ear to their niche in the ecosystem."
Other experts agree. Twelve years of research have increased his regard for yellow jackets, says Dr. Byron Reid, an entomologist at Purdue University. Most impressive, he says, is their learning ability. Laboratory tests at Purdue have shown that yellow jackets make a beeline for regular feeding troughs, even in the absence of food.
Disturb their nest, and yellow jackets remember it all summer. The smallest vibration brings them outside in droves. Slam the car door and run for your life.
"The yellow jacket is a noble beast. It's a beneficial insect that happens to sting you," says Dr. Reid.
He disputes the popular notion that yellow jackets become more aggressive in late summer. "It's just that there are more of them, and we are real nice to feed them sodas and watermelon at picnics and fairs," he says. "Then they land on our shirts and we swat at them."
Having destroyed much of their natural habitat, we should learn to accept these insects, he says. We ought to have picnics of bread and cheese and vegetables, foods they largely ignore. But that won't happen, says Dr. Reid. "Our Labor Day mind-set is, 'Dammit, I want my pork barbecue sandwich.' "
The sandwich draws yellow jackets, and all hell breaks loose. Killing one insect only exacerbates the problem. When crushed, some species emit chemicals -- alarm pheromones -- that alert the others, triggering a cavalry charge.