Cicadian Rhythms

No, not circadian rhythms, but the rhythm of Cicadas. While enjoying a pre-Christmas camping break, Cicadas were emerging from their long-time underground domains to transform into short-lived flying insects. Some areas where we went to collect wood had already experienced a burst of new arrivals and the sound was very loud in places as male Cicadas tried to attract females before their short lives ended and the cycle began once more. Our campsite was, thankfully, not yet inundated with noisy Cicadas, but they were slowly emerging and looking for any place to climb and begin their moulting process. So it was that we spotted one such Cicada and I’d always wanted to record the full process as it happened and this day I had the opportunity to do so. And having a new video camera to do this with made it even more satisfying.

Waiting for emerging Cicada - Wonnangatta River Victoria - (source: Grahame)

Waiting for emerging Cicada – Wonnangatta River Victoria – (source: Grahame)

As a bit of background, Cicadas are the loudest insects in the world and can produce sounds so loud that it can become unbearable and quite painful to the ear. We once camped at Jamieson (from memory) where the Cicadas had just emerged and, standing near to a tree they were in, you almost had to shout to be heard by someone standing next to you. Thankfully this wasn’t the case at our campsite for the week we camped there, but who knows how long that would remain the case as more of the Cicadas emerged. The ones that had emerged were certainly starting up a good deal of noise, small in number as they were. I pity any campers coming there for the Christmas holidays if the Cicadas were still in full song. The Cicadas tend to start up first thing in the morning and keep up the cacophony until the sun sets.

Emerging Cicada - Wonnangatta River Victoria - (source: Grahame)

Emerging Cicada – Wonnangatta River Victoria – (source: Grahame)

Emerging Cicada - Wonnangatta River Victoria

Emerging Cicada – Wonnangatta River Victoria

I first spotted the Cicada attempting to scale the metal post of the camping table provided by the Parks service, or whoever, and was failing miserably. After several attempts it fell onto its back and squirmed around for several minutes before finding its feet once again. In this time, I’d found a branch that I could use to entice the Cicada to climb, from whence I could then do some filming. At first the Cicada avoided the branch, but when I left it lying against the table and moved away, it decided that the branch was its best option. I was certain that it had reached a stage where it was going to moult no matter what and it seemed the case as the Cicada didn’t climb all that far up the branch before coming to a halt. So I placed the branch against a rock and got ready with my camera and soon enough it was quite obvious that things were about to happen.

Emerging Cicada - Wonnangatta River Victoria

Emerging Cicada – Wonnangatta River Victoria

Emerging Cicada - Wonnangatta River Victoria

Emerging Cicada – Wonnangatta River Victoria

And things did start to happen. I guess after around seven years in the ground, when the time comes to experience daylight, things do happen at a rapid pace. The event actually took around half and hour before the Cicada was fully clear of its old shell. At first you could see the back of the Cicada begin to bulge and eventually split open revealing the back of the newly emerging Cicada fly. The head emerged first and then started lots of movement as the Cicada had to clear itself of what looked like ganglions that eventually separated from the new body. There were brief periods where the Cicada appeared to be resting, as this was no doubt a pretty strenuous task, and then more movement followed. Finally the Cicada was almost out and then in a final move it lurched back towards the branch and pulled out the last of its body from within the shell. I found it interesting how the old shell remained steadfastly attached to the branch even when the Cicada was fully arched outwards, placing what looked like a lot of weight some distance from the branch.

Emerging Cicada - Wonnangatta River Victoria

Emerging Cicada – Wonnangatta River Victoria

Emerging Cicada - Wonnangatta River Victoria

Emerging Cicada – Wonnangatta River Victoria

Once fully out, the Cicada quickly clambered up the branch a short distance and came to a halt opposite to the camera. I’m not sure whether this was a tactic to hide itself from the camera and watchers, or that it wanted to be out of the direct sun and catch a bit of the breeze blowing through. The wings now took some time to fully expand, slowing stretching out and drying. The wing expanding activity wasn’t anywhere near as interesting as the emergence, so I didn’t follow the full process. Oddly enough, after leaving the Cicada alone for a while, I came back to have a look at how it was faring and it had returned to the shell where all of this had begun. Maybe it was giving its final respects to its old self that had provided it a home for the last seven years. Not long after it had flown off to start its turn at the Cicada minstrel show.

Emerged Cicada - Wonnangatta River Victoria - (source: Grahame)

Emerged Cicada – Wonnangatta River Victoria – (source: Grahame)

Emerged Cicada - Wonnangatta River Victoria - (source: Grahame)

Emerged Cicada – Wonnangatta River Victoria – (source: Grahame)

Emerged Cicada - Wonnangatta River Victoria - (source: Grahame)

Emerged Cicada – Wonnangatta River Victoria – (source: Grahame)

Anyway, I managed to film the entire emergence sequence and I’m pretty happy with how it came out. Watching the entire event in real time isn’t the most exciting thing, so I sped the sequence up by 10x to reduce it to around three minutes overall.

 

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