Resource Specialization in Puddling Lepidoptera

Lepidoptera feed at mud puddles, dung, and carrion in a behavior known as puddling. Sodium and sometimes protein are feeding cues, are actively collected, and play a potentially important role in lepidopteran nutritional and mating ecology. We showed that montane butterßy species have feeding preferences among mud, herbivore dung, and carnivore dung, and that these preferences differed among butterßy species. The puddling substrates varied in soluble sodium content, with mud having the lowest concentrations and carnivore dung having the highest. Within one species, Pieris napiL., visit frequencies tomud versus dungmatched visit frequencies to sand trays Þlled with sodium solutions matching the concentrations seen in mud or dung. This suggests that the preference hierarchy of this species is driven by soluble sodium concentration. Overall, the results indicate that lepidopteran species specializeondifferentpuddling substrates, likelyobtainingdifferent arrays of nutrients. This suggests that there are speciesor family-speciÞc roles for puddling nutrients in the overall nutrient budget of the insects.