Common Mormon
Papilio polytes
Painting a poisonous butterfly’s pattern onto its own wings
Male Common Mormons have black wings crossed by a bold white band, but females often evolve into several distinct forms, one of which nearly copies the wing pattern of the highly toxic Crimson Rose. This sexual dimorphism, in which females mimic another species, is a classic case study in insect mimicry and genetics.
Key figures
- Wingspan
- About 90–100 mm; wing color differs markedly between males and females
- Life cycle
- About one month from egg to adult; more than 3 generations a year in warm regions
- Habitat
- Urban gardens, citrus orchards, and low-elevation secondary forest
- Diet
- Larvae feed on leaves of citrus, Sichuan pepper, and other Rutaceae plants; adults visit flowers for nectar
- Mimicry
- Some females have wing patterns that mimic the highly toxic Crimson Rose, a classic case of Batesian mimicry
- False Head
- Hindwing tails and markings form a false-antenna pattern that draws attacks to the wing margin rather than the head
Life cycle
Egg → Larva (five instars) → Pupa → Adult
Ecological role
As a common flower-visiting and leaf-feeding insect on citrus and other Rutaceae plants, the Common Mormon’s larvae are frequently seen feeding in orchards. The mimicry shown by its females also makes it a familiar example for observing mimicry relationships between species.
Did you know
Birds often mistake a swallowtail’s tail for its head and peck at it. This false-head trick lets the butterfly fly off after losing only a wing corner — a far smaller cost than a strike to the real head.
Range
Southern China, India through Southeast Asia, and southern Japan
Status
Common; highly adaptable to urban and agricultural areas
Anatomy
- Forewing — Black with patterning; the primary feature for telling males from females and individuals apart
- Hindwing — Crossed by a jade-white band; in males this marking is stable and does not vary between individuals
- Tail — Extends like a false antenna, drawing a predator’s attention to the wing edge instead of the head
- Antennae — Club-shaped with a swollen tip, used mainly to detect the scent of host plants
- Compound Eyes — Large, helping it recognize the wing patterns of others and locate flowers in flight
- Abdomen — Females have external genitalia at the tip, used to probe the underside of leaves before laying eggs
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