Sunny Side Up. Delicate but abundant in the Blue Ridge region in spring and summer, sulphur butterflies are usually lemon yellow in color, and sometimes orange or pinkish, with medium-sized wings rimmed in black. As is often the case in the animal kingdom, the paler-hued females aren’t quite as showy.
In For a Landing. Sulphurs are commonly spotted sipping nectar in flower gardens, resting at roadsides, or flitting over lawns, open meadows, park grounds, stream banks and fields of alfalfa and clover. They are among the most easily recognized butterflies in the Southeast.
Flight Pattern. Despite its fragility, the sulphur is a powerful pilot, flying close to the ground at high speed. Before settling in one spot to roost, this fluttery creature will fly erratically around a tree or shrub (it may look confused, but this is just part of the process) then typically select a yellow or reddish leaf as a landing spot.
Garden Variety. Adult sulphurs drink sugary, high-energy nectar from many different types of plants, including clover, milkweed, goldenrod, asters, dandelions, thistles, verbenas and sunflowers.
Nose for Nectar. Equipped with relatively long tongues, these insects can reach deep into tubular flowers most other butterflies can’t access.
Open Arms. The male woos the female by making contact with her wings, which she alternately flicks open and closed to signal that she’s receptive to his advances.
Lean and Green. Sulphur caterpillars are slender and just as colorful as their winged counterparts but camouflaged well among leaves; they are bright green, streaked with black dots bordering light-colored lines, and covered with short, fine hairs. During this stage of their growth, the insects build tents in host plants – generally senna, alfalfa, clover or another legume – and spend most of their time eating.
Hanging Out. When it’s ready, the caterpillar spins tiny silk threads, attaches itself to its chosen surface, and forms a chrysalis with pointed ends and a hump in the middle. This temporary, leaf-shaped home is usually yellow or green with pink or green streaks. Close inspection often reveals the veined wings of the butterfly developing inside.
Southbound. Most sulphurs from the Blue Ridge states migrate in winter. On fall days, butterfly watchers driving in open country are apt to spot the bright yellow beauties crossing the road from north to south.