Butterfly pas de deux

Candalides xanthospilos (Yellow-spotted Blue). Click to enlarge.

Last week I found myself at the ballet. It wasn’t exactly a traditional ballet; it took place in the open air. The venue was a forest in the lower Blue Mountains, the stage was a blade of grass, and the dancers stood less than 20 millimetres tall. The plot, however, was a classic love story and the choreography was perfect.

I was just taking a short break from driving, a wander in the bush to stretch the legs and see what was about. An orchestra of cicadas buzzed in the angophoras — sensuous trees with smooth pink, dimpled bark, related to eucalypts. What happened next seemed beautifully impromptu.

Allegro

The two principal dancers made their entrance circling each other close to the ground. Fluttering through dappled sunlight, flashes of white alternated with glimpses of yellow, blue and brown. Their flight was mesmerising and brilliant. As I was to discover, they were courting.

Entrée

I followed them to where they landed, one behind the other, on a blade of grass. With grand pageantry, the female stood in front with the male edging closer. He curled his abdomen forward towards her, performed a deft pirouette…and suddenly they were joined.

Adagio

They remained linked tail-to-tail for ten minutes, gradually changing the angle of their wings and bodies in a graceful, slow-motion pas de deux. Their moves flowed with strenuous lunges and pliés. Together they raised their abdomens toward the vertical, joined at the apex. Two individuals with their wings closed became the shape of a single butterfly with wings open.

Coda

I glanced away for a moment, and when I looked back they’d gone. Flown off to continue their lives. The female will lay her eggs singly on a Pimelea (rice flower). A green caterpillar will hatch from each one and spend its nights eating leaves and buds. If it doesn’t become a snack for a bird or a host for a parasitic wasp, it will pupate in the leaf litter and the magical process of metamorphosis will begin. But that’s a different dance for another day.

Pimelea linifolia (Slender Rice-flower), flowering in August

Curtain Call

The female returned, and for the briefest moment opened her wings a tad…just enough to reveal two bold yellow spots. The male looks similar except for a blue suffusion where the female is brown. There is, after all, a reason for their name: Yellow-spotted Blue.

Location: Bluff Reserve, Glenbrook NSW

Cast: Candalides xanthospilos, Yellow-spotted Blue or Yellow-spot Blue (Lycaenidae)

In case you were wondering

• Butterflies mate facing in opposite directions with the tips of their abdomens locked together.
• With butterflies, the female is the larger sex.
• Lepidoptera (butterflies and moths) have complex genital structures varying from species to species. These can be a key feature for identification.
• The male’s external genitalia include a set of claspers which grip the female’s abdomen, holding the couple together during mating.
• If you’d like to know more about butterfly love, here’s a fun but informative article.