Monday, July 30, 2012

A commonplace miracle of transformation

Last Saturday night, at the Midwest Native Plant Conference (more on that in a soon to come post), many of the attendees set out on a nocturnal foray to look for anything interesting. As we passed a smallish white pine, I noticed several newly emerged annual cicada nymphs that had scaled partway up the trunk. Most had split open, and their inhabitants had liberated themselves, but we were interested to see that one nymph was still plodding its way up the tree. After spending a while at John Howard's mothing sheets, several of us circled back to check on the cicada nymph's progress.

By the time we returned, the nymph had reached the lowermost branch of the pine, and had moved out on it a foot or so and was firmly attached to its undersurface. One of its mates is in the background; that cicada has already emerged, leaving behind an empty shell. Annual cicadas in the genus Tibicen emerge every year, as you've no doubt guessed, with each crop spending at least two years under the ground feeding on tree roots. Finally, like strange little mud-caked zombies, some sort of cue triggers them to burst from the soil and commence the amazing transformation shown in this photo series.

I used my Canon Rebel T3i with its 100 mm macro lens and Speedlite 430 flash to make these photos. Fortunately, I had the camera's time and date stamp set correctly. The first photo, above, was made at 11:08 pm. The cicada within its soon to be former larval shell is pushing outwards; you can see the dorsal (upper) surface of the shell beginning to rupture.

By 11:19 pm, the cicada had broken through its shell and was rapidly expanding in size.

11:27 pm. The wing buds are nearly free.

11:30 pm. The stubby little wings - soon to grow much larger - pop free from the shell.

One minute later, 11:31 pm, and the animal's legs are nearly pulled free.

There! 11:34 pm and its legs are almost totally free. Short periods of rest were punctuated with flexing and wriggling of the legs, as the cicada pumped hemolymph into them and they grew and hardened. Note how the insect has taken on a beautiful bluish-green tint around the head and legs.


At 11:41, the cicada is hanging straight down, legs free, and giving periodic tremors as it pushes itself free. It is almost as if the insect is nearly imperceptibly oozing itself from its larval case.

At 11:45 pm, I shifted position and made this photo. The eyes are becoming pigmented and the wing buds are unfurling before our eyes.

By 12:08 am the animal was well on its way towards grabbing its nymph shell with its legs; bending forward and up as if executing an abdominal crunch.

By 12:10 am things were happening quickly. The animal has managed to reach its former shell, and has seized it with its legs. Not much of its abdomen remains imprisoned within the shell, and we were on full alert knowing the insect would soon pop free.

This photo is also stamped at 12:10 am; very shortly after the preceding photo the cicada pulled its abdomen completely free.

This is the last, or nearly the last, photo that I made, at 12:12 am. The cicada is completely liberated and will proceed to rapidly pump up, harden, and dry. I and my companions were pretty well beat by this time, and headed off for bed. Nonetheless, we hardly considered this hour or so of cicada-watching wasted time, as the process is one of those amazing little miracles that plays out untold thousands of times a night around here, but is very seldom seen.

I made this image of a nearby cicada that had emerged earlier and was a bit further along. In short order, the subject of my photo series will have reached this stage, a nearly adult lyric cicada, Tibicen lyricen. Come morning, the cicada will have made its way into the crown of the tree, and be fully flighted. If a male, it will add its buzz saw drone to the chorus of other cicadas; a symphony characteristic of the dog days of summer.

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8 comments:

Mary Ann said...

One of the coolest things I ever saw. :) It's really neat to see the timeline in the photos; by that time I was definitely pretty bleary-eyed, and didn't have a good sense of the time passing. It was a lovely little miracle. :)

Lisa at Greenbow said...

I am glad you took the time and effort to record this little miracle. I find these casings all over the garden yet I have never seen one go through this process. I might have to take to roaming the garden at night.

OpposableChums said...

Just amazing. This is what I love about your blog. You seek out, document, and publish some of the many miracles that surround us, but which most of us rarely get to see. I learn tons. Many thanks, Jim.

Carolyn said...

WOW! That was amazing! I love the sound of cicadas. Thank you so much for sharing these pics.

Carolyn said...

WOW--that is amazing! Love your blog--thanks.

Jack and Brenda said...

Great job of documenting this! It's really neat to see the process.

Jim McCormac said...

Thank you all for your comments! It was a very cool experience and well worth kneeling on the hard ground for an hour to make the photos!

Lisa Sells said...

Beautiful post, Jim...and fantastic images! Love your blogs!