Behavioral adaptations to pollen-feeding in Heliconius butterflies (Nymphalidae, Heliconiinae): An experiment using Lantana flowers

Butterflies in the genera Heliconius and Laparus obtain fitness-related ben efits from using amino acids derived from pollen. These butterflies have mo rphological features of the proboscis that facilitate pollen-feeding. Here we investigate behavioral characteristics potentially involved in pollen-ga thering. Analysis of four behavioral characters showed that pollen-feeding species manipulate Lantana flowers faster and more thoroughly compared to n on-pollen-feeding relatives. Although this suggests that pollen-feeding spe cies are potentially more efficient in harvesting pollen, every butterfly t ested successfully removed pollen from Lantana and non-pollen-feeding butte rflies generally extracted larger amounts of pollen than Heliconius and Lap arus. Morphological characteristics of the proboscis and the production of abundant fluid exudate help keep pollen attached in the proboscis for long periods of time-possibly key to Heliconius' and Laparus' ability to obtain amino acids from pollen. Our results, in concert with those of previous mor phological analysis, indicate that behavioral and structural attributes ass ociated with pollen-feeding in Heliconius and Laparus are subtle modificati ons of widespread butterfly characteristics and raise the question why othe r butterflies do not use pollen in their diet.