Page 131 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

BUTTERFLY CATERPILLARS

FAMILY Pieridae
DISTRIBUTION Southern and central United States, northern Mexico
HABITAT Weedy and disturbed locations, arid lands, parks, and gardens
HOST PLANTS Weedy Asteraceae: beggarticks (Bidens spp.) and marigolds
(Dyssodia spp.)
NOTE Aggressive caterpillar that develops into tiny, migrant adult
CONSERVATION STATUS Not evaluated, but common within its range

ADULT WINGSPAN
¾–1 in (20–25 mm)
CATERPILLAR LENGTH
⅝ in (16 mm)
NATHALIS IOLE
DAINTY SULPHUR 129

BOISDUVAL, 1836

Dainty Sulphur caterpillars hatch from eggs laid singly on

young leaves; first instars consume the eggshells after hatching.
Feeding by first instars causes “windowpaning” of leaves,
producing apparent holes between veins—in reality a layer of
transparent “cuticle.” Later instars consume entire leaves and
flower petals from the edge. Resting on stems or leaf midribs,

the caterpillars feed mainly at night and do not build nests. Their

defense appears to be based on camouflage and intimidatory

behavior in the final instar—waving the head end around when
threatened. The caterpillars also emit chemicals from a ventral
gland and setae, which may have a protective function.

There are four instars, and development from egg hatch to
pupation takes about three weeks, with adults emerging after
another two weeks. The annual northerly spread of Dainty
Sulphur butterflies in North America is facilitated by a broad

host range, rapid development, and the use of watercourses and
roadways as travel routes.

The Dainty Sulphur caterpillar is green with
indistinct, pale, vermiform markings, and
middorsal and spiracular stripes that may be
pale, red, or bold magenta. A pair of enlarged
pink, red, or magenta protuberances are present
behind the head. The head, true legs, and Actual size
claspers are green, and the spiracles are white.