This page contains pictures and information about Cicada Biology in general.
- Largest Cicada we found in Brisbane, body length over 10 meters, outside Culture Center
Cicadas are well known because their 'song' is the back ground
noise here in summer. Their empty shells often seen on tree trunks and
fences. The young nymphs live underground suck the roots of trees.
They may live underground for many years, come up from soil in summer, have the
final moulting and leave those empty shells. This is the male who sing the
song to attract female. Each species have different 'songs'.
Most of them are active during the day, a few species active only at
Female lays eggs on stem.
- Females cut slits in branches by ovipositor and lay eggs inside in group.
Nymphs hatch and drop to ground and burrow into soil. They have strong fore
legs to move in the soil. The young nymphs live underground suck the roots of trees.
Some species have the annual life-cycle and some may live underground for
years. There are usually five instars stages.
Empty shells on tree trunk
- Before becoming adults, they come up from soil, have the
final moulting and leave those empty shells. This usually
happen after dusk in summer night. After coming out for soil, they will find
any near-by vertical items, usually tree trunks or grass stems, climb up for
- Their empty shells are often seen on tree trunks and
- On end Dec 2007 in Karawatha forest (we believe it would be the same for
most other area in Brisbane), many adults emerge together and
clusters of empty nymph skins (called exuviae) were seen around the bases
of tree trunks. We had been visited the forest every week for the last few
months and did not remember seeing so many exuviae, although we noticed
those Double Drum Cicadas had started singing few weeks ago.
- Every medium to large size tree trunks, at least two or three exuviaes
were found. Some large tree trunks had more than 20. Some exuviaes were even seen on tall
grasses and vertical rock surfaces.
- We also saw many new holes of diameter 25mm on footpaths in the forest. Of
course there were many similar holes on the forest ground, but not seen
because covered by fallen plants materials.
- In that day, we also saw some of those cicadas flying between gum tree
tops. Some area in the forest, the songs were so loud that we could not hear each other when
we were talking face to face.
- In general, just before emerging, those matured nymphs will dig their way
from the root underground where they live and move to just below the soil
surface. They may be waiting for some environment signals or conditions to
emerge. Then suddenly all of them are synchronized together and come out
from the ground. They find the closest vertical surface, such as a large
tree trunk, climb up about half a meter then start to emerge to become
- Most cicada species, including this Double
Drummer, emerge at night. The
cicada in the following pictures could emerge a bit later than normal. It
had already emerged outside the exuviae when we first saw it.
- 11:00am already emerged outside exuviae, head downwards
- 11:10am wings started expanding, head moving upwards
- 11:15am wings fully opened
- 11:30am wings folded into tent shape position.
- Then the cicada would keep in this position until both its wings and skin
were harden. Its pale body colour would become darken as well.
Cicadas are familiar in Brisbane because their 'songs' are the back ground
noise here in summer.
of Floury Baker Cicada.
8.0 seconds of sound waveform and spectrum.
- This is the male who sing the
song to attract female. Only the males have the sound producing organ but
both male and female have the hearing organ. Each species have different 'songs' which are
produced by two organs called timbals on each side of their abdomen. The sound
is produced by tymbals, an organ with mechanism working like the children's tin clicker toys. The
male cicadas vibrate the membranes by internal muscle and the sound is resonate
with the drum-like cavity in the abdomen and this amplify the sound. The songs are
primarily for finding mate, but may also for aggregation of males and repel
the Floury Baker Cicada singing.
Cicada's Natural Enemy
- One hot summer weekend when I was working in front
of my computer on this Brisbane Insects and Spiders web site, as usual I heard many of
this Floury Baker Cicadas singing outside in our backyard on the Maple tree. Suddenly I
heard a new cicada song. The song had quite different pattern which I had never heard before. I
thought there must be a new species of cicadas came to visit us. I immediately
took my camera outside and look for it. What I found was not a new cicada species.
Instead it was a Floury Baker Cicada attacked by a Praying Mantid.
The cicada might try to deter the mantid but with no luck.
- Beside mantids, spiders are also cicada's major natural enemy. The first
picture above shows the Red Back
Spider having a large meal, a Brown Bunyip
Cicada. The second picture shows a Golden
Orb Spider captured another cicada. Third picture shows a bad luck Clanger
on spider web.
- Reference and links:
- 1. Insects
of Australia, CSIRO, Division of Entomology, Melbourne University
Press, 2nd Edition 1991, pp 464.
- 2. Family
CICADIDAE - Australian Biological Resources Study, Department of the Environment and
- 3. Cicadas
– our Summer Singers - Geoff Monteith, Queensland Museum, September 2000.
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