page_title: Polygonia c-album
section_title: Larva
hierarchical_section_title: Polygonia c-album / Reproduction and life history / Life history / Larva
caption_attribution_description: Polygonia c-album (Larva)
context_page_description: Polygonia c-album, the comma, is a food generalist butterfly species belonging to the family Nymphalidae. The angular notches on the edges of the forewings are characteristic of the genus Polygonia, which is why species in the genus are commonly referred to as anglewing butterflies. Comma butterflies can be identified by their prominent orange and dark brown/black dorsal wings.
  To reduce predation, both the larval and adult stages exhibit protective camouflage, mimicking bird droppings and fallen leaves, respectively. During the later stage of development, the larvae also develop strong spines along their backs. The species is commonly found in Europe, North Africa, and Asia, and contains several subspecies. Although the species is not migratory, the butterflies are strong fliers, resulting in an open population structure with high gene flow and increased genetic variation.
context_section_description: The larval period is separated into five distinct stages or instars. During the first three instars, the comma larvae have a cryptic appearance to avoid detection while they primarily stay on the underside of leaves. Fourth and fifth instar larvae search for food more actively. However, the beginning of the fourth instar also marks the development of black, white, and orange patterns. To avoid predation despite its conspicuous appearance, the larva develops strong spines along its body. The larvae have a continuous white marking along their backs to mimic bird droppings. In its final instar, the white colouration disappears but the spines persist.
  Three possibilities describing why spines may develop during later instars are as follows: smaller larvae cannot sustain the spines, larger larvae benefit more from spines as their predators shift from invertebrates to vertebrates, or because an effective spine pattern cannot be achieved upon the surface area of the smaller larvae.
  Aside from the formation of spines, no other defence against predators appears to be present. While fourth and fifth instar larvae are rarely preyed upon by the same predator, removal of the spines leads to repeated predation, indicating that no chemical defence mechanism exists to deter enemies.
caption: Larva
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