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, singing at night

Bladder Cicadas are large in size. However, they are not easily noticed because of their good camouflage and only active at night. 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 the 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 first 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 my car. Carefully inspected the tree, 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 heard the loud noise for a few evenings.




They feed on the plants by punching its needle like mouth into the stem and suck the juice.

In early summer 2002, I found another Bladder cicada just outside my office in Yeerongpilly, Brisbane. In the evening before heading home, I heard a familiar sound. Searching for about a minute, I saw the cicada singing on a board leaf tree about a meter above ground. When I came closer, it dropped onto the ground. Details please check another section below.



This must be a male because only male cicada will call.

Unlike other cicadas which always calling during the day, Bladder Cicada calls at night.

Bladder Cicada only calling for a short while, about half an hour, after dark in the evening. It has a large, hollow abdomen, which acts as an echo chamber. We recorded its calling 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.

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. Might be we came too close, the cicada dropped itself onto the ground. It stayed 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 and 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 do this when facing dangers. This trick sometimes works 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.

Reference:
1. Wildlife of Greater Brisbane - Queensland Museum: Brisbane (1997), p83.
2. Species Cystosoma saundersii Westwood, 1842 - Australian Faunal Directory, Australian Biological Resources Study.