Northeastern California is experiencing a cold spring with fewer than usual butterflies to be seen. Therefore, a few days ago I was happy to see this checkered white (Pontia protodice) near the Wayman Barn in Ash Creek Wildlife Area between Adin and Lookout CA.
Male checkered whites have charcoal markings on their front wings while females have grey markings on their front and hind wings. Adults that fly when it is cooler (early spring or later in the fall) are generally darker and more heavily patterned than those seen in the heat of summer. Adults feed on nectar from a wide variety of plants.
Adult checkered whites do not recognize the opposite sex by their markings but rather by differential UV reflectivity. The spindle-shaped eggs are laid singly, most often on the fruits of the Mustard Family (Brassicaceae) although they can also be deposited on stems.
Checkered white larvae have grey heads with yellow patches, grey bodies with yellow stripes and rows of black spots and numerous hairs over the body. The larvae prefer the flowers and fruits of mustard family members but will eat the leaves. In the South the checkered white larvae are called cabbageworms because they are often found on cabbage, kale and other cultivated mustard family crops where they can become pests and cause economic damage.
Although often associated with the South, checkered whites have colonized the northern states, except Washington and New England, and are also found into Canada. They are common in virtually any disturbed, dry, open area.
A synonym for Pontia protodice is Pieris protodice.