Tuesday, September 30, 2008
The Blessed Event, and a Series of Unusual Events
Controlling the urge to use bold-fonted capital letters and multiple punctuation marks, I am excited to announce giant swallowtail butterflies (Papilio cresphontes) are breeding on the property. Ok, just one " ! "
This blessed event has been anticipated since I first sighted the species in September 2006. The adults have been plentiful all of the summer of 2008, drifting through the gardens and even through the breezeway while we were sitting sipping iced tea. A few weeks ago I saw a pair flying circles around each other above the kumquat tree and the nearby rue (Ruta graveolens) both of which are larval food for the species. So, like I said, it seemed likely if not inevitable that egg-laying would occur. Today I found three p. cresphontes caterpillars, a delightfully expected surprise that unfolded in a series of unusual events.
So it was late afternoon and I was either doing some paperwork in my office or reading the political blogs, um, not sure which. Anyway, a voice calls from outside "Hey come look at this." My husband had spotted a caterpillar making its way across the concrete driveway. My eyes literally bugged out when I saw and realized this was the long awaited bird poop caterpillar. The shape, texture and coloration mimic bird droppings and serve as camouflage to protect against predation as the larva feeds and grows. This caterpillar was about 1.5 inches long and making its way toward the dog snoozing nearby. I picked it up to carry it to a suitable plant, and it briefly everted its osmeterium, a bright orange forked organ located at the top of the head. You can see a bit of it in one of the photos here. The osmeterium is used to frighten would-be predators; in the oldest instars it also has an odor which supposedly is offensive to spiders and such. I didn't smell anything, but I am no spider.
We all know caterpillars will wander; but where was this one coming from? I carried it to the big rue plant in the back 40; and there I found another one among the leaves of the plant (okay another "!") well disguised. So at that point I theorized our dog must have been squirreling in the underbrush, gotten a caterpillar attached to her coat which then dropped or crawled off when she flopped on the driveway; or maybe she shook it off. Huh!
A bit later I was closing up shop for the day and noticed another bird poop ("!") crawling across the deck in the breezeway. So much for the dog theory. This 2nd one was headed for the driveway and away from . . . a tiny rue plant. I had sort of forgotten about the planter my mom had brought by a while ago. In it are anthurium, ivy, dracaena, and one little rue. She had no idea what the plant was, just that it looked good and was only $1 at the Dollar Store. Anyway, I put the planter on a table on the deck; we sit there and sip iced tea, discuss politics and watch giant swallowtail butterflies drift by. None of us noticed the caterpillars on the plant, but you can see the leaves and stems are pretty chewed up.
Thanks again for the plant, Mom. Without it I might have missed the September 2008 breeding of P. cresphontes. ! ! ! ! ! !