clouded sulphur

Clouded sulphur is a medium-sized to large butterfly.

On the male the upperside of both wings are yellow with a wide, solid, black border at the outer margins. There is a small black spot near the middle of the leading margin of the forewing and a small silver spot with an orange border on the hindwing. The female wings have fainter black markings and have yellow spots within the black border. Clouded sulphur rarely lands with wings open so these features are seldom useful in the field.

The underside of both wings is yellow with a row of small, faint, brown, submarginal spots. The hindwing has a double spot of silver rimmed with pink.

There is also a white-form female with greenish-white wings.

The caterpillar is green and up to 1⅜″ long. As with all caterpillars, there is a row of small, oval to round openings (spiracles) on the on each side of the body. The spiracles appear on the first segment of the thorax and the first through eighth segments of the abdomen. There is a white stripe in this spiracular area extending from just behind the head to the anal plate. The stripe is edged in black or dark green at the bottom and may have a thin bar of pink or orange in the center.

Wingspan: 1⅜″ to 2¾″

Orange sulphur (Colias eurytheme) has at least some orange on the upperside of the hindwing, but this is only visible in flight. It often has some orange visible on the underside of the forewing. The black band on the outer margin of the upperside of the forewing is wider, but this is not distinguishable in the field.

Fields, lawns, roadsides, meadows, and other open areas.

Two or three broods from mid-May to late October.

They can often be seen in large numbers at mud puddles.

Females lay pale eggs singly near the center of a leaflet on host plants.

The last brood overwinters as pupae.

White clover (Trifolium repens) and sweet clover (Melilotus spp) are the preferred hosts. Other foods include Alfalfa (Medicago sativa ssp. sativa), bird’s-foot trefoil (Lotus corniculatus var. corniculatus), vetches (Vicia), and other plants in the pea family (Fabaceae).

Flower nectar

Sources

7, 21, 24, 27, 29, 30, 71, 75, 82, 83.

Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu, 7/23/2025).

Clouded Sulphurs
Andree Reno Sanborn

Colias philodice (Clouded Sulphur)
Allen Chartier

Clouded Sulphur (Pieridae: Colias philodice) on Thistle Blossom
Carl Barrentine

Clouded Sulphur
Bryan Glemboski

Clouded Sulphur (Pieridae: Colias philodice) on Grass Stem
Carl Barrentine

Clouded Sulphur butterfly
Quiscalus107

Location: Saint Cloud, MN

In my covered raised garden, several have appeared 9/14/2025-9/15/2025. I had to rescue them.

Location: Pennington Co MN