Variable Cracker (Hamadryas feronia [Linnaeus]) Wing span: 2 7/8 - 3 1/4 inches (7.3 - 8.3 cm). Identification: Upperside of forewing is brown and white, sometimes bluish, with a red bar in the cell; hindwing eyespots are each black with a white center, surrounded by a blue ring. Underside of hindwing is white or tan-white with submarginal black rings. Life history: Adults perch on tree trunks head downward with their wings spread open, and males make a cracking noise when they fly. Before dark, adults gather on a single tree, then disperse to roost in nearby trees or shrubs. Flight: Throughout the year in the tropics, July-December in South Texas. Caterpillar hosts: Vine Dalechampia in the family Euphorbiaceae. Adult food: Rotting fruit and other non-floral resources. Habitat: Tropical forest edges, cutover second growth. Range: Argentina and Brazil north through tropical America to Mexico. Strays to the lower Rio Grande Valley of South Texas.