Hopper1, Houtaro, etc. | Kamen Rider Gotchard

One of the older, though obviously not the oldest, Chemies, Buglesia's nature is emblematic of that of the Plant Chemies as a whole: generally accepting of humans, yet not getting too attached to any one human at a time. Somewhat of a prankster (though far from the worst Chemy in that respect), Buglesia is a scent specialist.
While there are no alchemists still alive from that era, Buglesia has admitted her first exposure to the Alchemist Union was not a positive one. Her current nature can be taken as a softening of what came before.