Orellana A, Erazo M. 2002. Possible population decline of the swallowtail
Papilio polyxenes
americus Kollar (Lepidoptera: Papilionidae) in the intra-Andean valley of Mérida, Venezuela. Entomotropica 17(2):189-190.
Since the second half of the 90's, the swallowtail butterfly,
Papilio polyxenes americus Kollar, 1859, a formerly common species, has become scarce or may even be disappearing from the Chama river basin of Andean Mérida, Venezuela. No concrete explanations are given for the fact, but it is presumed that it may be linked to human activities, especially the use of pesticides.