Thistle Butterfly (Painted Lady)


Thistle Butterfly (Painted Lady) Life StagesThistle Butterfly (Painted Lady) Life Stages
Thistle Butterfly Caterpillar in Silk Nest with FrassThistle Butterfly Caterpillar in Silk Nest with Frass
Caterpillar Feeding Damage on Soybean PlantThistle Caterpillar Feeding Damage on Thistle Plant
Artichoke Plant with Severe Feeding Damage from Caterpillar FeedingArtichoke Plant with Severe Feeding Damage from Caterpillars

HOSTS

  • Artichoke  
  • Sunflowers 
  • Soybeans
  • Ornamentals  
  • Weedy Thistles

OVERVIEW

The thistle butterfly (Vanessa cardui), also known as the painted lady butterfly, belongs to the family Nymphalidae. While they do not overwinter in Utah, they are common in the spring and summer months. The larval stage of the thistle butterfly can cause damage to host plants as they feed.

DESCRIPTION

Adults have orange wings with black and white patterns that span 2-3 inches (50-76 mm) across. Larvae are spiny, brown/black with yellow markings. Mature caterpillars reach 1.5-1.75 (38-45 mm) inches long.

BIOLOGY

Egg | Larva | Pupa | Adult
Adults migrate to the southwest U.S. or Mexico for winter and migrate back north in spring. Eggs are laid singly on host plants and will hatch after 3-5 days. As they feed on the host plant, caterpillars will web together leaves with silk, creating a leaf tent. Pupation occurs in protected sites on or near the host plant. There can be several generations of thistle butterflies per year in Utah.

SYMPTOMS

Caterpillars feed on leaves, creating ragged holes and leaving silk webbing and frass behind.

SCOUTING

  •  Start scouting during the late spring to midsummer for egg-laying adults, eggs, larvae, and feeding damage

GENERAL MANAGEMENT

  • Caterpillar populations will rarely reach treatment thresholds in plants other than soybeans or artichokes. 
  • Treatment thresholds will vary depending on the life stage of the host plants.













Always verify that the product you are using is labeled for thistle butterfly control on artichokes. Pesticide products are available for both home gardeners and commercial growers.
Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement for any specific brand name products listed on this page.