Description: It is considered one of the most medically important caterpillars in South America due to its highly potent hemotoxic venom, capable of causing severe hemorrhagic syndromes in humans after skin contact. The larva shows a thick, cylindrical body with brownish-green tones and rows of branched spines that act as an efficient defensive system. The adult stage is a nocturnal moth with muted brown wings, moderate wingspan, and discreet flight behavior. The life cycle includes egg, larva, pupa, and adult, with the larval stage being the most relevant both ecologically and medically.

Geographic distribution: Its range is concentrated in the southern and southeastern regions of Brazil, especially in Rio Grande do Sul, Santa Catarina, Paraná, and São Paulo, extending into northeastern Argentina, Paraguay, and Uruguay. Records indicate a preference for temperate and subtropical climates. In recent decades, the species has expanded into urban and peri-urban areas, following the planting of suitable host trees.

Habitat: It inhabits Atlantic forests, gallery forests, riverine woodlands, and human-modified environments such as parks, gardens, and tree-lined streets. During daylight hours, larvae remain motionless on trunks and branches, relying on cryptic coloration to avoid detection. Humid environments with well-defined seasons favor its development.

Feeding: The larva is strictly herbivorous, feeding on the leaves of several native and introduced trees, including Ficus, Schinus, Prunus, and Citrus species. Feeding activity is mainly nocturnal and often occurs in small groups. Adults have a short lifespan and show minimal feeding behavior, limited to plant fluids or nectar.

Behavior: Early instars are gregarious, forming dense clusters on tree trunks that enhance collective defense. Activity peaks at night, when larvae feed and move. When disturbed, individuals remain immobile, depending on camouflage and the toxic effect of their spines.

Reproduction: Females lay eggs in organized clusters on the bark of host trees. After hatching, larvae pass through several instars before pupating in the soil or within bark crevices. The complete life cycle may last several months and is strongly influenced by temperature and humidity.

Conservation status: The species is not globally threatened, but its relevance lies in its significant public health impact. Habitat conservation should be accompanied by education and prevention programs, particularly in rural and urban areas where human contact is common.

Author of this compilation: EcoRegistros – 26/01/2026