Marine Puddling in Papilio Polytes (lepidoptera: Papilionidae)

Smedly & Eisner (1995, 1996) stressed the difficulties that terrestrial herbivores, including Lepidoptera, suffer in order to fulfill their need for sodium, an essential ion plentiful in the seas, but in short supply in plants. Adult Lepidoptera drink from puddles, edges of streams, carrion, and excreta from which they obtain sodium and proteins (Beck et al. 1999). Puddling behavior is typically, although not exclusively, carried on by males (Boggs et al. 1991; Sculley & Boggs 1996). It has been demonstrated that sodium acquisition from puddles enables males to provide mates with sodium, presumably via the spermatophore (Pivnik & McNeil 1987; Smedly & Eisner 1996). Sodium intake by males affects their reproductive success, while the transfer of sodium from male to female enhances the reproductive successes of both females and eggs (Pivnik & McNeil 1987) since females subsequently transfer sodium to their eggs (Smedly & Eisner 1996). Location of resources, which are usually rare and patchily distributed (i.e., puddles with the appropriate salt concentration), is not a simple matter for Lepidoptera, which might use both visual (Papilionidae, Pieridae) and olfactory stimuli (Lycaenidae, Nymphalidae) to locate them (Beck et al. 1999). The sea, an easy to locate source of sodium, is basically unexploited by butterflies.