Mission Blue Butterfly - Life Cycle

Life Cycle

Each year marks the birth of a new generation of Mission Blues, as only one generation exists per year. The butterfly lays its eggs on the leaves, buds and seed pods of L. albifrons, Lupinus formosus and Lupinus variicolor. The eggs are usually laid on the upper side of new lupine leaves. Eggs generally hatch within six to ten days and the first and second instar larvae feed on the mesophyll of the lupine plants. The caterpillars, extremely small, feed for a short time and then crawl to the plant base where they enter a dormant state, known as diapause, until the late winter or the following spring. Diapause usually begins about three weeks after eclosion and begins about the same time as the host plant shifts its energy to flower and seed production. When the caterpillar comes out of its diapause and begins feeding, it occasionally sheds its skin to accommodate its growth.

As the larvae feed and grow, native ants may gather and indicate the presence of larger Mission Blue larvae. The ants will often stand on the caterpillar and tap it with their antennae. In response, the caterpillar secretes honeydew. The ants eat honeydew and in return it is likely, through this symbiotic relationship, that the ants ward off predators.

Once the caterpillar is fully grown, it leaves the larval stage and enters the pupal stage of development. The fully grown caterpillar forms a chrysalis after securing itself to a surface which is generally a lupine stem or leaf. They shed their outer skin, revealing their chrysalid. This stage lasts about ten days while the adult butterfly develops within the chrysalid. The butterfly can be sighted as early as late March in places like the summit of San Bruno Mountain or the Twin Peaks. They persist well into June when they will be seen perched on a lupine plant or feeding on coastal buckwheat flowers. Day to day for the adult butterfly is mostly spent foraging for nectar, flying, mating and for the females, laying eggs. Nearly equal time is spent between perching, feeding and flying. The adult Mission Blue lives approximately one week; during this time, the females lay the eggs on the host plant. The complete Mission Blue butterfly life cycle lasts one year.