Colias philodice (clouded sulphur butterfly)

Overview

• Scientific name: Colias philodice

• Common name: Clouded sulphur

• Family: Pieridae (Whites and sulphurs)

• Range: Widespread across North America, from southern Canada to northern Mexico.

• Habitat: Open fields, prairies, meadows, roadside edges, old pastures, and disturbed areas with legumes.

• Appearance: Medium-sized yellow butterfly with black wing borders; females may be white (alba form).

Life Cycle

1. Egg

   • Laid singly on host plant leaves (legumes).

2. Larva (caterpillar)

   • Green with yellow side stripes; feeds on foliage of leguminous plants.

3. Pupa (chrysalis)

   • Green or brown, attached to stems or leaves.

4. Adult butterfly

   • Active from spring through late fall; multiple broods in warm regions.

Ecological Role

1. Pollinator

• Adults visit a wide variety of flowers, especially composites and legumes, aiding in pollination of prairie and meadow plants (e.g., asters, goldenrods, clovers).

2. Herbivore (Larvae)

• Caterpillars feed on leaves of native legumes, especially clovers and vetches, playing a role in regulating plant populations and forming part of grassland food webs.

3. Prey Species

• Eggs, larvae, and adults are food for birds (sparrows, swallows), small mammals, spiders, and predatory insects (mantids, assassin bugs).

• Caterpillars host parasitoid wasps and tachinid flies, contributing to parasitoid diversity.

4. Indicator of Open-Habitat Health

• Abundant in healthy meadows and prairies; presence signals legume-rich habitats and overall grassland integrity.

Best Native Host Plants (for Caterpillars)

Colias philodice caterpillars feed exclusively on native legumes (Fabaceae). Important host species in the Midwest/Great Lakes include:

Primary Hosts

1. White prairie clover (Dalea candida)

   • Upright perennial; thrives in dry prairies.

2. Purple prairie clover (Dalea purpurea)

   • Deep-rooted; valuable nectar and host plant.

3. Canada milk-vetch (Astragalus canadensis)

   • Prefers moist prairies and open wood edges.

4. American vetch (Vicia americana)

   • Climbing vine; grows in woodlands and prairies.

5. Bush clovers (Lespedeza spp.)

   • Includes roundhead and slender bush clover; important late-season forage.

Secondary Hosts (less common)

• Tick-trefoils (Desmodium spp.)

• Goat’s rue (Tephrosia virginiana)

• Leadplant (Amorpha canescens)

Best Native Nectar Plants (for Adults)

Adults nectar broadly on prairie flowers; prioritize long-blooming species:

• Spring/Summer: Wild bergamot (Monarda fistulosa), coneflowers (Echinacea spp.), milkweeds (Asclepias spp.)

• Summer/Fall: Blazing stars (Liatris spp.), black-eyed Susan (Rudbeckia hirta), goldenrods (Solidago spp.), asters (Symphyotrichum spp.)

Habitat Recommendations

• Plant a mix of native legumes (prairie clovers, vetches, bush clovers) to provide continuous larval food sources.

• Combine legumes with diverse nectar plants (asters, goldenrods, bergamot) to support adults and other pollinators.

• Plant in open, sunny areas resembling natural prairies or meadows.

• Cluster plantings (3–5+ per species) improve butterfly detection and use.

• Avoid pesticides and mow only late fall or early spring to protect overwintering chrysalids.

Conservation Notes

• Widespread and common, but populations benefit from prairie restoration and native legume plantings.

• Declines can occur where clovers are replaced by non-native grasses or pesticides reduce larval survival.

• Planting native legumes supports not only clouded sulphurs but also other butterflies (e.g., orange sulphur Colias eurytheme) and native bees.

Why Supporting Colias philodice Benefits Ecosystems

• Legume host plants also improve soil nitrogen and support diverse bee communities.

• Clouded sulphurs provide food for higher trophic levels (birds, spiders, predatory insects).

• Their broad geographic range means plantings benefit both local and migrating individuals.