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The life cycle and behavior of honeybees and yellow jackets is quite different, so in several places in your essay, I was a bit confused which you were writing about. Honeybees store honey in order to overwinter and do not forage during that time, nor are the colonies typically very aggressive. The summer bees that produce the honey stores are a distinct generation of short-lived bees (a few weeks), whereas the overwintering bees are long-lived (several months). The colonies are thus perennial. On the other hand, yellow jackets, in most of their range, are an annual species (as you noted). Only the mated queens overwinter, the workers dying off in the fall, probably from programmed death. For the first phase of the annual cycle, the colony produces workers to increase colony size, but in the late summer and fall phase, they invest a lot of resource in producing male and female sexuals. These mate (outbreed), the males die and the mated females overwinter, as you noted. I am not convinced that hunger is the source of their fall aggressiveness. Here is an alternate possibility--- the colony is protecting its sexual males and females because these are its future generation, its only hope of having a descendant colony in the following year. Considering that yellow jacket nests have long been preyed upon by large mammals such as bears, they have a lot of reason to be nasty in the fall. They are cuing to large, warm, carbon dioxide-emitting creatures, and don't stop to ask questions.

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Interesting! Is this alternate possibility a theory of yours, or have you found studies that have looked into it? It certainly makes a lot of sense -- many yellow jackets nests around us are dug up by bears, opossums, raccoons, and armadillos each fall, so it makes sense as a protective mechanism to preserve continuation of the colony.

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Fair question. The life cycle of yellow jackets and paper wasps is factual and well known. A late season peak in colony size (number of workers) is followed by a burst in the production of sexuals. The theory part is that in an annual species, this strategy maximizes the likelihood of descendants in the next generation. The same strategy is pursued by annual weeds that produce a lot of seed in the fall. As for whether the selective agent is predation by mammals , that is conjecture on my part. Evidence in support would require quantifying how much such predation reduces sexual output and therefore reproduction into the next generation. I have seen yellow jacket nests almost completely destroyed by bears. Suicide attacks by the colony's workers would seem very much worthwhile.

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I'm so grateful we don't have yellowjackets here in New Zealand, because I'm horrified at the thought of not wearing bright colours to avoid enraging them. My entire wardrobe is chock-full of lime green, orange and lots of other loud colours. I'd be doomed!

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The video of that bike surrounded by a swarm is terrifying! I would be mad too if my food supply was shrinking. I will have to look more closely at the wasps I kill now instead of just immediately stomping them...

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I was running a trail marathon in autumn about thirty years ago when I ran past a yellowjacket nest right next to the narrow forest trail. I got stung a couple of times. On my hands! I wasn't going slow, so the little beasties must have been riled up by some competitor ahead of me. After the race I talked to other finishers and almost all had gotten bitten! Lesson learned: don't run forest trail marathons in the autumn!

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That seems to happen to me each fall but with mountain biking - also a sport where multiple people ahead of you can stir up the "little beasties" as you call them. The take away -- try to be first in line. Unfortunately, I'm not fast enough to be first...

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Nor am I! I came in third place in that particular race but only by virtue of there being only 3 finishers! Maybe the yellowjackets disabled the rest!

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If you can't tell the difference between bees and wasps, perhaps you shouldn't be writing about nature.

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That’s not a terribly kind comment — I’m sorry you felt the need to post it. I am aware that yellow jackets are in the wasp family, but that is not the point of the piece. I hope you were able to enjoy this issue on some level.

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