Painted Lady (Larvae)
Vanessa cardui
Painted lady egg.
Painted lady pupa.
Painted lady larva and associated hemp damage.
Painted lady adult butterfly.
Feeding damage to hemp foliage is ragged.
Painted lady damage to hemp foliage.
Hosts
- Field-grown hemp
- over 300 plant species primarily in the Compositae (aster, daisy, thistle, sunflower family), Malvaceae (mallow family), Boraginaceae (forget-me-not family), and Fabaceae (legume family) families.
Description
The larval stage is a spiny, brown/black caterpillar with yellow markings. Larvae are often secluded inside a leaf tent held together by silk. Adult butterflies are orange with black and white markings.
Life Cycle
Egg | Larva | Pupa | Adult
- Adults migrate to the southwest U.S. or Mexico for winter and migrate back north in spring.
- Several generations per year after arriving in Utah.
- Eggs are laid on host plants.
- Larvae feed on host plants and pupate in protected sites on or off the host.
Damaging Lifestage(s): Larva
Damage Symptoms
Caterpillars chew leaves, resulting in leaves with ragged holes that are often webbed together with silk.
Time for Concern
Late spring throughout summer.
When and Where to Scout
- Eggs are laid on top of leaves in early summer.
- Caterpillars will emerge three to five days after eggs are laid.
- Peak feeding occurs in summer.
- Begin scouting late spring to midsummer for egg-laying adults, eggs, larvae, and feeding damage
Threat Level
Low. Natural enemies usually keep population sizes minimal and damage to crop yield insignificant.
Occurrence in Utah
This insect occurs in Utah, but has not been identified as a pest in Utah hemp. It has been seen in hemp in neighboring states.
Management
- Hemp plants can tolerate low levels of damage and no management is necessary.
- Hand-pick and destroy larvae.
Look-alikes
None
Photo Credits
- Whitney Cranshaw, Colorado State University, Bugwood.org