The song of the cicada is only produced by the males as a mating call. Each
species has its own distinctive call and will only attract females of its own
kind, even though similar species may co-exist. Some large species such as the
Green Grocer, Yellow Monday, and Double Drummer produce a noise in excess of 120
decibels at close range, this is approaching the pain threshold of the human
ear. In contrast, some smaller species have songs so high in pitch, that the
noise is beyond the range of human hearing.
How they produce their songs is still being researched today, but the organs
that produce the sound are the tymbals, a pair of ribbed membranes at the base
of the abdomen. Contracting the internal tymbal muscles causes the tymbals to
buckle inwards and produce a pulse of sound. By relaxing these muscles, the
tymbals pop back to their original position. In some species of cicadas, a pulse
of sound is produced as each rib buckles.
male and female cicadas have organs for hearing. A pair of large, mirror-like
membranes, the tympana, receive the sound. The tympana are connected to an
auditory organ by a short tendon. When the male sings, it crease it's tympana so
that it won't be deafened by its own noise.
Many species of cicada sing during the warmth of the day. This noise actually
repels birds, probably because the noise is painful to the birds' ears and
interferes with their normal communication. The males of many cicada species
group, such as the Green Grocer, Yellow Monday and Double Drummer, group
together when singing. This increases the volume of noise, makes it harder to
locate where the sound is coming from and reduces the chances of bird predation.
Other species of cicada only sing at dusk. These species tend to be weak fliers,
such as the Bladder Cicada. They gain some measure of protection from birds by
confining their activity to dusk.
In addition to the calling or mating song, many species possess a distress
song. This is usually a broken and erratic noise emitted when an individual is
captured. Some species also have a courtship song, a quiet call that is sung
only after a female has been attracted nearby using the calling song.
Cicadas feed on a huge range of plants, including eucalypts and grasses. They
feed by piercing the surface of plants with their mouth stylets. The sap is then
sucked up through a tube formed by the concave surfaces of two of the stylets.
They are not harmful to trees, although in some cases the growth of the tree may
slow, due to the amount of sap consumed. Cicadas do not bit, even when handled,
although their claws may feel sharp as they cling to the skin.
Birds, bats, spiders, ants, mantids and tree crickets all prey on cicadas.
They also provide food for the larva of the Cicada-killer Wasps and are also
parasitised by the larvae of Feather-horned Beetles (family Rhipiceridae).
It is thought that the nymphs of the larger, common Australian species of cicada
may live underground for around 6-7 years. This may explain why adult cicadas
are more abundant during some seasons than others, with peaks occurring every
In contrast to its nymph stage, the life of the adult cicadas is
very short, lasting a matter of weeks. Once the adult cicadas have mated, the
female cicada lays its eggs by piercing the plant stems and inserting the eggs
into the slits. The eggs hatch into small wingless cicadas known as nymphs. They
fall to the ground and burrow below the surface, where they live on the sap from
plant roots. Over the period of several years, the nymphs grow, shedding their
skin at intervals.
Once the nymph reaches full size, it will dig its way to
the surface with specially adapted front legs. It usually surfaces as night
falls in the late spring or early summer. Then, climbing the nearest tree trunk
or other fixture, it will shed its skin for the last time, emerging as a
fully-winged adult cicada.
Source: Various including
Australian Museum Online: Fact Sheets Cicadas,
The Wonderful World of Insects: The Singing Cicadas