Description: 1-1 1/2" (25-38
mm). Small. Bright yellow above with black forewings (upper wings)
tips and margins on male, black often
reduced to spot on female or series of connected spots at ends
of veins. Female sometimes white with black markings. Below,
yellow-green with dark smudges, including rust-colored spot in
upper hindwings (lower wings) margin.
Life Cycle: Egg minute. Caterpillar, to 3/4" (19
mm), green with fine pile and white side stripes; feeds on
legumes such as
senna (Cassia) and partridge pea (Chamaecrista fasciculata),
clovers (Trifolium), as well as hog peanut (Amphicarpa).
Flight: Year-round in far South; May-October
farther north.
Habitat: Many disturbed and natural open areas,
especially roadsides and fields.
Range: Lake States and New England south, between
Mississippi Valley and Atlantic to Gulf, South America, and West
Indies.
Discussion: Although common fairly far north in late summer, the
Little Yellow cannot survive temperate or northern winters. The
species refills the Northeast and Midwest every year with fresh
immigrants, which furnish 1 or 2 more broods before the autumn
chill kills them. Vast numbers of Little Yellows emigrate to the
Caribbean and Atlantic. Columbus is supposed to have witnessed
from the decks of the Santa Maria one such mass movement, probably
consisting of this species or the Cloudless Giant Sulphur.
