Butterflies are always a delight to spot in the garden and one common Utah visitor is the painted lady butterfly.  I thought it might be appropriate to take moment to pause and pay tribute to my lady, the painted lady butterfly.  I pulled this segment from the broader June 29, 2019 Utah Pests Landscape IPM Pest Advisory, enjoy – and Happy New Year!


Painted Lady Caterpillars

Caterpillar of painted lady butterfly feeding on yarrow. This native insect is experiencing a very high population in the Intermountain West in 2019.

A large migration of painted lady butterflies was reported from California to Utah and Colorado earlier this spring. Currently in northern Utah, late-stage larvae are now visible feeding on weeds and herbaceous plants. In some areas, they are causing economic damage.

Painted lady butterflies spend the winter in the southern southwest deserts, and migrate north each spring and summer. According to University of California-Davis entomologists, their numbers explode in years with high rainfall that results in dense desert wildflowers. Before 2019, the last most notable high migration and high rainfall there was 2005.

Painted lady butterfly, shown here in late summer getting pollen from gray rabbitbrush.

Colorado entomologists reports that the last mass migration there was 2017. Butterflies are also commonly seen in late summer, making their migratory trek back to their winter breeding grounds.

UC Davis also reports that the following plants and plant families are hosts:

  • Malvaceae (mallows)
  • Boraginaceae (notably comfrey and borage)
  • Asteraceae (asters)
  • sunflower
  • Fabaceae (legumes, especially lupines, but not alfalfa or close relatives)
  • Verbenaceae (verbenas)
  • Plantaginaceae (large group of flowering plants that includes penstemon, snapdragons, many wildflowers, and many ornamental annuals)
  • Scrophulariaceae (figworts and relatives)
  • Solanaceae (tomatoes and relatives) are not hosts

Check out this fact sheet by entomologists at Colorado State University.