Belongs to a striking group of large diurnal lepidopterans characterized by a wingspan ranging from 70 to 100 millimeters. The upperside of the forewings is a solid, matte brownish-black, lacking any distinctive light bands. In contrast, the hindwings feature a highly diagnostic cluster of ruby-red to deep pinkish-purple spots arranged in a crescent-like pattern near the outer margins, along with prominent tail-like extensions characteristic of the swallowtail family. The caterpillars exhibit exceptional protective mimicry; early instars resemble bird droppings with a brown and white coloration, while mature larvae display a mottled grayish-brown pattern with whitish patches, enabling them to blend seamlessly against the bark of their host trees.
Geographical distribution: This species is widely distributed throughout the Neotropics, extending from southern Texas in the United States, southward across all regions of Mexico and Central America (including nations such as Guatemala, Costa Rica, and Panama), down into South America, where it spans tropical and subtropical zones in Colombia, Venezuela, Ecuador, Peru, Bolivia, Paraguay, northern Argentina, and most of Brazil.
Habitat: Occurs predominantly in disturbed forest borders, humid and dry tropical forests, secondary growth woodlands, forest clearings, riparian zones, and agricultural landscapes. It has successfully colonized anthropized environments and is highly common in citrus orchards, suburban gardens, and urban parks rich in nectar-producing ornamental plants, ranging from sea level up to elevations of approximately 1,400 meters.
Feeding: In the larval stage, it is a highly specialized herbivore that feeds exclusively on the foliage of plants in the family Rutaceae. Its primary host plants belong to the genus Citrus, including sweet orange, lemon, and lime trees, as well as wild native species from the genera Zanthoxylum, Casimiroa, and Ruta. Adults are active nectar-feeders, visiting a wide variety of flowers such as Lantana, Asclepias, Bougainvillea, and Ixora. Furthermore, adult males frequently engage in mud-puddling, congregating on damp soil or riverbanks to suck up essential dissolved salts and minerals.
Behavior: Adults are powerful and fast-flying butterflies that actively patrol the canopy and understory during sunny daylight hours. Unlike most other swallowtail larvae, the caterpillars are highly gregarious throughout their development. During the day, they gather in dense, compact groups on the lower trunk or larger branches of the host tree, relying on communal camouflage to avoid predators. At night, they march upward in unison to feed on the leaves. When threatened, they evert a specialized, reversible gland called an osmeterium located behind the head, which is bright yellow or orange and releases a pungent, chemical odor composed of organic acids to repel invertebrate predators like ants and wasps.
Reproduction: The reproductive cycle begins when the female deposits clusters of up to forty spherical, pale-yellow eggs on the underside of young host plant leaves. The incubation period lasts between five and eight days. Upon hatching, the larvae progress through five distinct instars over a period of approximately three weeks. Pupation takes place on twigs, branches, or nearby artificial structures. The chrysalis is highly cryptic, closely resembling a broken twig or a piece of dry tree bark, held upright by a silken girdle. The pupal stage lasts about two weeks before the adult butterfly emerges.
Conservation status: This insect is not currently listed under any threat category on the IUCN Red List. It is widely regarded as a common and stable species throughout its geographic range. However, localized populations can experience declines due to the heavy application of chemical pesticides in commercial citrus groves, where the caterpillars are sometimes classified as minor agricultural pests due to their highly localized defoliation behavior.
Compilation and publication: EcoRegistros – 12/09/2026