Yellow jackets are a common pest during harvest. They swarm thickly over the bins of arriving fruit, and explore odd crevices in the winery equipment. Spring through summer, yellow jackets (a species of wasp, not a bee) bring insects, meat and fish to feed larvae in their rapidly growing colony. The larvae in turn give off a sweet nectar that fuels and satisfies the adults. By late summer or early September, the larvae are all grown and the result is about 5,000 hungry adults. Without the larval love juice, an occasional flower nectar or sip of tree sap is no longer enough to fuel their full-flight metabolisms. They are looking for meat and sugar, which is why they are common pests at summer’s end picnics. Yellow jackets are considered beneficial insects for most of the growing season because they prey on soft-bellied beetles, whiteflies, aphids, and other insects that can plague vineyards. However, it's estimated that 1% of humans are allergic to yellow jacket venom, and yellow jackets can sting more than once, so exercise caution when visiting wineries during harvest. Eradicating nests does not solve the problem as yellow jackets can travel a mile or more in search of food sources. Sometimes they swarm over half tons bins of ripe fruit while the fruit is on the trailer in the vineyard, and they will latch on and ride all the way to winery. Slow movements prevent annoying and frightening the swarming jacks, and the occasional well-aimed flick gets rid of the most curious. This season, however, the wasps seem to be arriving earlier, and they are voracious and insistent. Today one landed on the bridge of my sunglasses, while both hands were busy, natch. We’ve seen swollen lips, ears, faces, and fingers from the angry stings of yellow jackets. Once, a jack was hiding inside the handle of the crushpad pallet-jack and when I squeezed the handle to pump it up I got stung. They also hide under the lever of the hose sprayer, under tank handles, and under the forklift pedals. On the Schmidt Sting Pain Index, a yellow jacket sting is a respectable 2.0: "Hot and smoky, almost irreverent. ImagineW. C. Fields extinguishing a cigar on your tongue. "













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