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Story by Harvey Thommasen with Photography by Nick Didlick While fishing last week I saw hanging from the branch of an alder tree, over the water's edge, a grey, globe-shaped, football sized, yellow jacket paper nest. I was lucky, it was hanging down at head level and if I hadn't noticed it I would have waded face-first into it.
Brightly colored yellow and black wasps were buzzing in and out of the nest - and I cautiously went wide to avoid disturbing them. The hot colors of wasps serve as a visual warning signal to us, one usually reenforced by the memory of a painful, burning sting. But most fishermen know that a wasp struggling in the surface film won’t last long if a trout is around. Fish readily take wasps, apparently without fear of being stung, and a wasp pattern can be a good attractor at times - especially where a busy nests hangs low to the water. In coastal a valleys, in the Pacific Northwest, one can expect to find up to six kinds of yellow jacket wasps:
Except for the Baldfaced hornet, all of these yellowjackets look similar - bold yellow and black striped insects with conical hind-body (abdomen), and four, transparent and strongly veined wings. The Bald-faced hornet is our largest yellowjacket wasp species, and it differs from the other kinds of local yellow-jackets in that the transverse markings are coloured black and white, not yellow and black. Otherwise, it is easily recognized as being a wasp. The Dolichovespula yellowjackets build paper nests above ground in trees, bushes, or under roof sills. The Paravespula yellowjackets, and the Vespula yellowjacket form large nests of paper cells in abandoned rodent burrows, in other kinds of underground cavities, and sometimes inside building crevices. The paper used in constructing their nests is remarkably similar to that made by people. It would seem that wasps are the original paper makers. They chew up weathered or decaying wood fibres, and then use this material in the construction of combs for their young, and in the construction of the tough outer paper envelope. Yellowjackets are a kind of social wasp. They are the wasp equivalent of the bumblebee or honeybee - insects which have developed an elaborate social organization made up of queens and many workers. In spring, fertile queens that have survived the winter emerge from hibernation sites in leaf litter, under loose bark, or in house crevices in the spring and search out nest sites to begin their own colony of yellowjackets. After finding a suitable site, the queen gathers nesting material and constructs a small embryo nest. This embryo nests consists of a few hexagonal cells and a covering around them. Into each of these cells, the queen lays a single egg. Larvae hatch from the eggs in about a week. They are fed chewed up pieces of insects which the queen has hunted down and killed. The queen yellowjacket feeds her young larvae for about 12 days. Pupation then takes place, and after another twelve days fully developed wasp workers emerge. Once they emerge the queen no longer has to go out to hunt. Instead she stays in the nest and devotes her time to laying hundreds of worker wasps. These workers will hunt and bring food back to the queen, they will feed developing larvae, they forage for wood fibre and water, they enlarge the nest and build new hexagonal larval nests. By the time September rolls around, a yellow jacket colony can consist of several hundred workers, and a thousand or more developing larvae. In late summer or early fall, the workers begin to construct larger than normal egg cells. These cells are known as reproductive cells and are used to raise males and females. The males and new queens that emerge from these reproductive cells leave the nest in search of mates from other wasp colonies.
By September, all wasp colonies are in decline, and workers go exploring. They spend less and less time hunting for insects to feed colony youngsters; and more and more time sipping sweet juices of fermenting fruits and berries (and sugary residue in pop cans), and the juices of rotting salmon flesh. This is a good time of year to try a yellowjacket fly as a searching pattern. Perhaps not coincidentally this is also the season that the chance of being stung by a wasp becomes more and more likely. Only the recently fertilized queens will survive the fall. All other workers and the males will die when the first freezing storms hit the coast. And come the next spring, warm sunshine will once again rouse the queens to repeat the cycle. Wasps benefit us by feeding and destroying great quantities of insects - including many that are garden pests. Wasps probably play a role in pollination of some plants. On the other hand, wasps and their stings can wreck a fishing trip. Farmer's produce can also be adversely affected when there is a lot of yellowjackets around. These wasps not only injure the fruit, but farm workers often refuse to enter the fields to harvest the crop. Some people develop life threatening allergic reactions to yellow-jacket stings. However across all of North America fewer than 50 people die each year as a result of bee and wasp sting reactions - far fewer than die from such things as penicillin allergic reactions or from lightening strikes.
Wasps are a part of nature about which flyfishers should know something. Watch for their nests in low hanging branches along forested trails, or over the water in wading lanes. And avoid any areas where you see wasps going to ground. Stepping on an underground nest can send a swarm into the air that is hard to outrun in chest waders. But keep a few wasp patterns in your box, for those slow days in the summer or fall, when the trout are sulking. A hot yellow and black fly can sometimes bring a violent strike. |
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1. Forest yellowjackets (Vespula acadica)
At about the same time the males and new queens emerge from their reproductive cells and leave the nest colony; the reigning yellowjacket queen starts to lose control of her colony. She lays fewer and fewer eggs. She may die of old age, or be killed by one of the newly emerged queens.
