Monday, April 22, 2013

Spring Butterflies

One of the most welcome signs that spring has arrived is the sighting of tiny butterflies.  We are now seeing a lot of small white butterflies fluttering close to the ground.  The one above on my thumb tip (no, that is not my bald head!) is an falcate orangetip male, Anthocharis midea.  The females are all white on top, lacking the orange tip. (more pictures here)

Spring azure- Wikimedia
The first emerging butterflies in flight are usually the spring azures, Celastrina ladon.  These tiny blue butterflies flutter along inches off the ground in search of the very few nectar sources available.  They look like a "bald" Eastern tailed-blue, lacking the tiny hair at the end of the hind wing as well as the orange spots on the wings.

The spring azure lays its eggs early, producing caterpillars that feed on flowers and seeds as well as early leaves of plants.  This is a useful trait during the receding winter when leaves are at a premium.

Spring azure- Wikimedia
The azure's emergence is welcomed by some species of ants.  Like their cousins, the other "blues," the spring azure caterpillars produce a sweet substance on their backs called honey dew.  Some species of ants actually farm these caterpillars like tiny sweet cows, protecting them from predators in trade for licking up the honey dew.

Spring azure caterpillar- T. Murray*
Their adult lifespan is only a few days so mating takes precedence over searching for nectar.  The males will collect at puddles and wet soil, picking up the minerals to add to their sperm gift to the females.  Much of their frantic flight is patrolling for females which are settled on the low lying foliage.  More spring azure pictures here.

* Tom Murray's author of Insects of New England and New York.  His caterpillar pictures are at this PBase link.