Page 53 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World
P. 53
BUTTERFLY CATERPILLARS
FAMILY Papilionidae
DISTRIBUTION Southern India and Sri Lanka, northeast India to southern
China, southern Japan, South Korea, and Southeast Asia
(Malay Peninsula, Indonesia, and the Philippines)
HABITAT Open forests
HOST PLANTS Members of Rutaceae, including Citrus spp., Euodia spp.,
Fortunella spp., Toddalia spp., and Zanthoxylum spp.
NOTE Caterpillar that develops into a snake’s head look-alike
CONSERVATION STATUS Not evaluated, but very common
ADULT WINGSPAN
4–4⅝ in (100–120 mm)
CATERPILLAR LENGTH
2–2⅛ in (50–55 mm)
PAPILIO HELENUS
RED HELEN 51
LINNAEUS, 1758
From the tiny second instar to the fourth, Red Helen caterpillars
resemble bird droppings as a camouflage defense against
predation. The final (fifth) instar sees a dramatic transformation
both in color and pattern as the larvae take on the typical snake’s
head mimicry of many Papilio species. Should it be threatened,
though, the caterpillar inflates a red, fleshy, forked appendage—
the osmeterium—from behind its head. This can be quite
startling and also smells unpleasant. When not feeding, the
larvae rest exposed on branches and twigs on the host plant,
relying on their color to remain undetected.
The larval period lasts from 26 to 30 days. The chrysalis is green
(when among fresh twigs and leaves) or brown (when on woody
or dry branches) and deeply curved outward, supported by
a single-strand silk harness. The pupal period lasts 14 to 22 days.
The Red Helen butterfly is a large, black swallowtail with white
spots on its hindwings, often seen cruising pathways or clearings
in the forest, nectaring at flowers, or mud-puddling. Within its
tropical range, the species occurs year round.
The Red Helen caterpillar is a deep green color,
with a mottled brown band separating the thorax
and abdomen and two oblique brown and white
bands mid-abdomen that meet dorsally. The
underbelly is white, while the head and ventral
thorax are dark brown. The eyespots, complete
with slit pupils, are connected by a green
“stained glass” pattern mid-thorax. Actual size

