On Country
Meet the Cicada
From: https://australian.museum/learn/animals/ insects/cicadas-superfamily-cicadoidea/
• Cicadas belong to the Order – Hemiptera, which includes all insects with piercing and sucking mouthparts. They are not to be confused with crickets, which bite, and have powerful jaws.
• Cicadas have a stout body with 2 pairs of wings, often with firm veins, and 3 pairs of legs, and large eyes.
• Their mouth parts are enclosed in a long thin beak like sheath, which lies backwards from the lower surface of the head between their legs when the insect is not feeding.
• The sheath contains 4 fine needle-like styles it uses for piercing the surface of plants. Once into the plant’s leaf, or stem, it sucks the plant’s sap through the tube, and into its digestive system.
• The lifespan of an adult cicada lasts for a few weeks.
• After mating, the adult female lays its eggs by piercing plant stems with an egg-laying spike at the tip of the abdomen, and inserting the eggs into the slits it has made.
• The eggs hatch into small wingless cicadas known as nymphs. These fall to the ground and burrow below the surface.
• Nymph cicadas may live underground for 6 to 7 years, feeding on plant roots, while shedding their exoskeleton at each moult. Some American cicadas spend as long as 17 years underground.
• When the nymph reaches its full size, it digs its way to the surface with its front legs. These are specially adapted for digging.
• Nymph emergence is often cued to nightfall, and the beginning of the warm season, early Kambarang. (Can students suggest why?) The nymph climbs onto a tree trunk (or a fence post) and sheds its skin for the last time. The fully winged adult cicada, which emerges, leaves its old empty skin behind.
Show Video – Cicada emerging from its shell from the YouTube clip: https://www.youtube.com/ watch?v=v91hk6ppKqY
Activity
Looking for and Listening to Cicadas:
Background
1. There are 2 ways of ‘meeting’ a cicada.
Their discarded exoskeleton is often visible on a tree trunk or a fence post.
2. It makes a loud noise – indeed, they are the loudest insect in the world. (Some large species produce a noise intensity in excess of 120 decibels at close range, approaching the pain threshold of the human ear).
When the air temperature reaches 28oC, during Kambarang, the male cicada begins to attract a mate. They ‘sing’, a process called ‘stridulation.’
• Cicadas have a hollow sound-producing organ on the side of their exoskeleton, in the region of the thorax, called a tymbal. It is hollow and covered with a membrane, strengthened with stiff ribs. A sequential buckling of the ribs resounds in the cavity, rather like a kettle drum.
• Similar to frog calls, each female cicada recognises the ‘signal song’ of its species and is attracted to the male.
• 2 species of cicadas in Western Australia are identified by their song – the Tick-Tocks (Physeema quadricinta), and the Sandgrinders (Arenopsaltria fullo) (9).
From: https://rewildperth.com.au
https://www.inaturalist.org/taxa/522534-Physeemaquadricincta/browse_photos
1. Students look and listen for evidence of cicadas, such as discarded exoskeletons.
2. If cicadas are ‘calling,’ students may record the cicada’s song.
Recording and information of how cicadas sing can be found at: https://www.youtube.com/watch?v=XCSOTbXQ4wY
Connected Learning Areas: English: Draw and label the parts of a cicada and create a written account of the ‘life of a cicada, using information from the Museum website (above), attaching evidence of video recordings of empty shells and song.