I went camping last weekend, and so did a few yellow jackets. They weren't out on a weekend getaway, of course — they live somewhere near the campground. And they seemed to have this crazy idea that it was their territory, not mine.
I've found that if I try to understand the lifestyle of insects or plants, I can more easily understand their behavior. That theory works for people, too, by the way.
Yellow jackets are wasps, and they are social hunters, living in colonies. The colonies are annual and contain workers, a fertilized queen and a few males. The nests are in protected, hollow places such as logs, stumps, abandoned rodent runs — or that place in your stone wall where a rock fell out.
Inseminated queens are the only ones to overwinter. As days warm in the spring, she emerges, selects a nest site and builds a small, paper nest in which to lay eggs. After the eggs hatch, the queen cares for the larvae for about three weeks. At that point, the new workers (small, infertile females) take over the job of caring for the larvae, while the queen occupies herself only with egg laying.
But workers have more work to do. The paper nest must be expanded, as the colony could grow into the hundreds. The nest paper is made by the workers chewing wood fiber into a paper-like pulp. In addition, the workers need to forage for food high in protein, which also must be pre-chewed before feeding it to the larvae and the queen.
Protein sources are largely insects, dead animals and fish. This is why yellow jackets think it would be a good idea for you to share your hamburger with them. Adult yellow jackets have a diet high in sugars, which explains why they want a sip of your lemonade or a bite of your fruit and other picnic goodies. Actually, fallen fruit and our garbage are common sources of these sugars.
As the season progresses, life in the colony changes a bit. New queens are growing and demand a lot of food late in the summer, which helps explain the workers' aggressiveness. The new queens will mate in mid-flight with a male, after which he promptly dies. The new queens will survive the winter, and start the whole process over again.
The old colony's population quickly diminishes in late fall as the founding queen dies and the workers leave the nest to die.
Now that we understand them a bit, how do we recognize these hard workers, that are often confused with hornets, honeybees and other flying insects? Yellow jackets have distinctive yellow and black markings on their bodies and faces. They are slender and smooth, compared to the smaller, thicker, fuzzy body of the honeybee. They also have an interesting side-to-side flight pattern before landing. Although they are loathed by many humans, they are, in fact, important predators of pest insects.
Their lance-like stinger allows them to sting repeatedly, although they do so only when defending the nest or feel trapped or otherwise threatened. Stings are painful but not dangerous unless you have an allergic reaction or are stung multiple times. Do not swat at them, yell or run when you see them, as that will make them more aggressive and they may chase you.
At times, it may be necessary to destroy a nest if it is located near human activity. Traps are available, which lure workers into it, but that doesn't destroy the nest. For that, use a chemical intended for the purpose, propelling the stream from a safe distance. And in this dry weather, don't even think of trying to burn them out! Remember, when frost comes, they'll be gone anyway.
Coming up: Kelly Brainard of Ashland Greenhouses will discuss construction and use of hoop houses, cold frames and other ways to extend the season. The class, from 7 to 9 p.m. on Thursday, Aug. 8, will be at the Southern Oregon Research and Extension Center, 569 Hanley Road, Central Point. The cost is $5. Call 541-776-7371 to register.
Carol Oneal is a past president of the OSU Jackson County Master Gardeners Association. Email her at email@example.com.