Hello, tsk I go away for a few days and all hell breaks out! Jasper Carrott's moling with a shotgun always amuses me. Hornet nests less so but I certainly wouldn't advocate blasting cocoons out of trees. The caterpillars have toxic hairs which they shed, so a cocoon bazookering thousands of hairs into the environment perhaps wasn't the best treatment. The flame thrower was a better move but pine trees have a reputation of being volatile if ignited.
So, if there's anything alive, install an écopiège around the tree. If there is nothing left but a smoldering tree top then a pheromone trap will trap the moths thus reducing the population for next year.
Any more info, please feel free to message me.