The false-head hypothesis in lycaenid butterflies: A review

Butterflies and moths (Order: Lepidoptera) are known for having a wide array of antipredator adaptions related to their wing coloration and patterns and have long been considered the model for examining animal mimicry. Butterflies use aposematic colors to warn prey of toxicity, mimic other dangerous and unpalatable animals, or mimic body parts such as eyes and heads to deflect predators to less vulnerable regions of their bodies. Multiple species within the family Lycaenidae have false heads at the apex of their hindwings which are believed to confuse predators and lure them to attack this region of their wing. These “heads” are composed of converging lines, eyespots, and threadlike “tails” projecting from the base of the wing. When attacked, this portion of the wing easily breaks off, allowing the butterfly to escape. Some studies have shown that false heads are accompanied by a variety of behaviors that further trick predators into attacking the base of their wings. These behaviors include hindwing movement along the sagittal plane as well as the butterfly moving in a seemingly random circular pattern and seem to enhance the false head. Very few recent, large-scale experimental studies have tested their impact of false heads on predation. This phenomenon should be reexamined utilizing large-scale manipulative laboratory experiments with predators in order to better understand the predator avoidance defense tactics across the tree of life.