Bladder Cicada - Cystosoma saundersii
Family Cicadidae
This page contains pictures and information about Bladder Cicadas that we found in the Brisbane area, Queensland, Australia.
- Male, body length 50mm
- Bladder Cicadas are large in size. However, they are not easily noticed because of their good camouflage. Their forewings are in leaf shape, opaque and green in colour. Their bodies and heads are also green with yellow-brown compound eyes. The male Bladder Cicadas have their greatly enlarged abdomen, largely hollow. This is the resonating chamber to amplify the loudness of their songs. Females are smaller in size and relatively smaller abdomen.
We found this Bladder Cicada in the front yard of our friend in Nambour, about 100km north from Brisbane. We heard a very loud noise when we arrived our friends house in a summer late evening. At first I thought there was the problem of my car engine. Then we found that the noise was coming from a tree next to us. By carefully inspection, we saw this Bladder Cicada hiding in the tree about 2m above the ground. We brought it home and put in on a tree in our backyard. Then we can hear the loud noise for a few evenings.
In early summer 2002, I found this cicada just outside my office in Yeerongpilly, Brisbane. In the evening just heading home, I hear the familiar sound. Searching for about a minute, I saw the cicada singing on a board leaf tree about a meter above ground.
The Cicada Song
- Unlike other cicadas which always calling during the day, Bladder Cicada only calling for a short while, about half an hour, after dark in the evening. They feed on the plants by punching its needle like mouth into the stem and suck the juice. This must be a male because only male cicada will call. It a large, hollow abdomen, which acts as an echo chamber. We have recorded its sound.
Listen
to this sound and see if you can tell this was from a cicada.
- 1.0 seconds and 0.2 seconds of sound waveforms
- The sound wave spectrum.
- From the waveform analyses, the calling song of Bladder Cicadas has the carrier frequency of 890Hz, modulated with 40 pulse per second. Both the carrier and pulse frequency are relatively low, which give the metallic sound.
Feigning Death Behaviour
We found that Bladder Cicada uses the 'play dead' trick to escape from predators. On a early summer day we found a male Bladder Cicada singing on a tree on a suburban street. We got close to take some pictures. May be we came too close, the cicada dropped itself onto the ground. It just lying on ground without any motion, just like dead. We used a small stick to disturb it and there was no response at all. We stopped the distortion, just wait and see. About a minute later, the cicada rolled back on foot and slowly walk away.
The 'play dead' trick is quite common in the insects world. We saw at least some bugs, stick insects and caterpillars will do this when facing with danger. This trick sometimes work because some predators do not eat dead or motionless prey. For those insects with camouflage pattern may work even better. The insect drops onto a new background and stays still, the predator may not found it again.
