Isn't this concluded through observational studies? Is it possible that its just not universally true, like it still impacts, idk, 0.01% of this ant's species due to gene diversity?
Could be due to the rate of encounter with this species vs. other species, could also be due to the consistency of response with more general vs. specific pheromones. You start with spiders with silk/pheromones that ants are a little more aggressive towards, then variance in that chemical makeup leads to fitness advantages. If the pheromone confers a strong advantage in a specific ant,