"Without explaining what's on my mind, I ask Nafus and Schreiner: Have they seen any recent invasions by exotic arthropods, or any dramatic population outbreaks among native ones? I inquire about arthropods rather than insects because it's a broader category, inclusive also of such charming non-insect invertebrates as ticks, centipedes, millipedes, and spiders. Asking a professional entomologist about arthropods (and not about, say, bugs) is a way of signaling at least some familiarity with the subject. Still, Nafus rocks backward in his chair, rebounding from the dumbness of my question. "We have invasions and outbreaks all the t"