Monthly Archives: August 2015

Butterfly of the season – May

Butterfly of the Season

The Sara Orangetip (Anthocharis sara) on California Rock Cress (Arabis sparsiflora)

The Sara Orangetip (Anthocharis sara) on California Rock Cress (Arabis sparsiflora)

The Sara orangetip is one of the first butterflies to fly in winter in southern California.  The males, with the brighter orange tipped wings, generally emerge a week or so before the females.  In my backyard just south of Anza they started to fly about the first week in February.  By mid-May there are just a few worn individuals flying around.  The male orangetips are beautiful to watch as they flit about searching for members of the opposite sex.

The larvae of most butterflies have specific food plants at which they will feed upon.  Without them the butterflies adapted to them will not multiply in your area.  The larvae of the sara orangetips feed specifically upon members of the mustard family (Brassicaceae); amongst them their favorites are California Rock Cress (Arabis sparsiflora), Nevada Rock Cress (Arabis perennans) (see photo below), Hall’s Caulanthus (Caulanthus hallii) and the Tansy Mustard (Descurainia pinnata).  The first two plants are perennials while the last are annuals.

Orange egg of a sara orangetip near the center of the flowers of Hall’s Caulanthus

Orange egg of a sara orangetip near the center of the flowers of Hall’s Caulanthus

Orangetip larva on Nevada Rockcress with well-developed seed pods.

Orangetip larva on Nevada Rockcress with well-developed seed pods.

The male orangetip shown above is feeding upon the nectar of the California Rock Cress.  It has its proboscis, a straw like structure, buried deep into one of the flowers.  It uses its proboscis to suck up the nectar from the flowers.  Even though larvae of most butterflies feed upon only specific plants the adult orangetips will feed upon the nectar of many plants even including the nectar of their larval food plants as shown above.

Once mated the female sara orangetip oviposits upon the flower stalk of the mustard food plant.  The egg starts as a cream yellow and within a day or so turns orange (figure below).  The egg hatches into a young caterpillar within about 5 to 7 days depending on temperature.  The warmer it is the faster the caterpillar develops within the egg.  The caterpillar begins by feeding upon either the flowers and/or developing seed pods of the food plant.  It grows as it feeds upon the seed pods of the food plant (bottom figure).  As it grows it begins to look very much like one of the seed pods and in near maturity it can sometime even be seen curling itself to look like a seed pod.

At maturity the caterpillar crawls down the mustard plant and begins what is called the wandering stage.  In this stage the caterpillar searches for a pupation site or a site at which to form the chrysalis.  It fastens the tip of its abdomen to a pad of silk and creates a silken girdle around its middle.  Shortly afterwards in goes through the remarkable process of pupation.  Once the pupa forms it generally enters diapause, a form of hibernation, where it waits for the following spring.  In diapause the chrysalis can wait for multiple years for when there is sufficient precipitation that favors the blooming of its food plants.  When that event occurs the adult butterfly emerges and the process begins again.