Monday, April 13, 2015

Orangetips of Spring

Falcate orangetip on spring beauty
This picture summarizes early spring, a falcate orangetip butterfly clinging to a spring beauty*, each of which is a harbinger of the season.

If you go into the woods now, you will notice a tiny white butterfly flitting frenetically around, and occasionally you may even notice a flash of orange on its tiny wing.  It may stop occasionally for a nectar load but usually it just appears confused.  The orange tells us that it is a male falcate orangetip, Anthocharis midea, and he is on patrol, looking for what tickles his fancy, a lady falcate.



Although they both carry the orangetip name, only the males have the orange on the upper wing.  Both sexes have an intricate green marbling on the underwings, almost like lichen on a rock.  This is effective camouflage as long as they keep their wings folded shut at rest.
Note wing spot- Photo by Miles M. Buddy **
Once they have mated, the female will deposit a single egg on a mustard leaf, fortunately a common plant in nature.  This behavior is a necessary precaution as her caterpillars not only feed on mustard, usually the flower petals or seeds, but they will on occasion feed on their siblings, a charming little cannibalistic trait.  The female reduces this risk by leaving a pheromone on the leaf to discourage other butterflies from depositing more eggs.

Chrysalis - Kim Fleming

They fly for only a few weeks and then are through for the year.  Their young caterpillars will go through several instar stages, then pupate in May.  The chrysalis has a spike at the head, and attached to a branch it perfectly mimics a thorn.  They overwinter in the chrysalis, sometimes for two or more years.  It is no wonder that they are frantic when they take flight in the spring.

Female falcate orangetip lay an egg on a mustard
Two days later I had the opportunity to see a female falcate orangetip landing on some tiny mustard family plants in the field at Bull Creek.   She seemed to be very determined in her efforts, bending down the tip of her abdomen to touch the plant.



After getting a few suboptimal pictures, I pulled one of the mustards and found her tiny golden egg on the stalk.  It is a beautiful shiny golden-orange to the naked eye.  With magnification you can see it is fluted along its length.

After she had laid several more eggs, a male came by and tried to hit on her.  She must have given him a signal that she was already full as he immediately took off in pursuit of a more receptive female.

The falcates only have one generation a year, but that seems to be enough, considering how many are flying right now.  The message here is to look carefully when you see a butterfly on a leaf or stem and you may get to see the beginning of a new life.

* Spring Beauty, Claytonia virginica is interesting as well.  It is one of many plants whose seeds are spread by ants, a process called myrmecochory. The seeds have a fleshy organ called an elaiosome that attracts ants. The ants take the seeds to their nest, eat the elaiosomes, and put the seeds in their nest debris, where they are protected until they germinate. They also get the added bonus of growing in a medium made richer by the ant nest debris."

** Miles M. Buddy is a 14 y.o. naturalist from North Carolina whose bio is at this Bugguide link

For in interesting Orangetip view from Great Britain, see bobscotney.blogspot.co.uk