Spots and Stripes of the American Lady

September 21, 2017 Posted by: Andrew Rosales

As you approach the visitors center of Cabrillo National Monument you may not notice the flurry of activity taking place about two-feet off the ground. However, if you stop and closely observe the Pink Everlasting (Pseudognaphalium ramosissimum) you might notice many small to medium sized caterpillars. These caterpillars are the larvae of the American Lady (Vanessa virginiensis) butterfly. These beauties are very similar to the Painted Lady butterfly but can be distinguished by the small white spot on the top area of the forewing. Also, the American Lady has two large spots on the underwing that differ from the four spots of the Painted Lady.
 

NPS Photo/Andrew Rosales

Fully grown larvae of the American Lady are approximately 1.4 inches in length. Their body color is variable. Some larvae are primarily yellow with thin black lines along their body segments. However, the larvae in the park show a median black band that is much wider so that the larvae appear to be black with narrow yellow lines. There is a row of large branched spines (scoli) with orange or red bases on each body segment, Abdominal segments two through eight typically have a conspicuous white spot on each side and there is usually a cream colored line that runs most of the length of their body.

NPS Photo/Andrew Rosales

The American Lady’s habitat ranges from southern Canada throughout the U.S. and into the northern half of Mexico. They may have three to four broods from May to November. The females lay single eggs on the leaves of the host plant. The larvae hatch and feed on the host plant. They also make small nests of leaves and silk. The larvae will then attach to the plant and begin the pupate phase by wiggling out of its skin to become a chrysalis. This species will also pupate in different colors depending on its surroundings. It can be yellow/green to a dull grey; from bright and shiny, to dull muted tones to match the habitat.

If you are planning to visit the park in the next few weeks, slow down and look for this beautiful lady. The American Lady Butterfly and its larvae are putting on a show right outside the Visitor Center’s front doors. 

Reference: http://entnemdept.ufl.edu/creatures/bfly/american_lady.htm#dist

 

American Lady, butterflies, Pink Everlasting