Vespid wasps, especially the family of hornets and yellowjackets, have alarm pheromones. This is why it's a very bad idea to kill a wasp: her sisters are likely

Vespid wasps, especially the family of hornets and yellowjackets, have alarm pheromones. This is why it's a very bad idea to kill a wasp: her sisters are likely to smell what you did, and may come and try to kill you right back. Damaging the body of a dead wasp can also release the pheromone, eliciting the same response. I don't know that we need a just-so story to explain a folkway around avoiding interference with the remains of deceased hymenopterans, but if we do, this is probably the strongest candidate.