Aleeta

Aleeta: The Floury Baker Cicada

Imagine a small, yet remarkable insect that has been around for centuries, with a unique appearance and a loud, almost musical call. That’s the Aleeta curvicosta, or more commonly known as the floury baker cicada. Native to Australia’s eastern coastline, this genus of cicadas is a fascinating creature indeed.

Distinctive Appearance and Behavior

The floury baker gets its name from its appearance, which resembles being dusted with flour. This medium-sized cicada has a body length of 2.9 cm and forewings that can stretch between 3-5.1 cm long. Its body is brown, covered in white downy filaments that can be easily rubbed off. These filaments are like tiny brushes, giving the cicada a unique texture.

Interestingly, the female floury baker is slightly larger than the male and has additional features such as a long, dark reddish-brown ninth abdominal segment and a long, downward-tilting ovipositor. This makes it easier for her to lay eggs in slits on branches, usually with 16 eggs per batch.

Unique Call and Emergence

The male call of the floury baker is one of its most distinctive features. It consists of a hissing-type sound produced by single muscular contractions clicking the tymbal inward, buckling 7–9 ribs. This occurs alternately on two tymbals at a frequency of about 143 Hz, producing a pulse repetition frequency of around 1050 per second.

Abdominal tracheal air sacs amplify sound and modulate its volume, pitch or tune by extending or raising the abdomen. This makes it one of Australia’s loudest cicadas, earning it the title ‘the best musician of them all.’

Nymph Stage and Life Cycle

After emerging from soil between November and February, the nymphs fall from branches to burrow into the soil. They grow and feed underground for 2-8 years before emerging to shed their final shell. The sex ratio is about 1:1 with a consistent emergence of 15 males for every female.

During emergence, the metabolic rate of the nymphs is 1.8 times the resting metabolic rate of adults. They emerge on most tree species but avoid Norfolk pine and broad-leaved paperbark. Adults appear between November and May, with a similar 92-day emergence period in South East Queensland.

Life Cycle and Predation

The nymph splits its cast down its back, extracts its head and clypeus, and unfolds its wings. Adult cicadas live for 2-4 weeks, feeding on sap from tree branches and mating/egg laying. They are usually solitary, perching facing downwards on branch tips.

Floury bakers are slow fliers, with speeds of 2.1-3.9 meters per second, making them easy targets for predators. Birds such as wrens, grey fantails, noisy miners, blue-faced honeyeaters, little wattlebirds, butcherbirds, magpie-larks, Torresian crows, white-faced herons, and tawny frogmouths prey on the adults.

Emerging nymphs are also vulnerable to predation by frogs and bearded dragons. The cicada-specific fungus Massospora affects adults, causing a drop in the tail end. Cicada killer wasps (Exeirus lateritius) prey on adults by stinging and paralysing them before carrying them to their burrows.

Collection and Cultural Significance

The shells of adult floury bakers are collected by children, often kept as pets temporarily due to sap needs. Poems about cicadas have been published for children in the past, highlighting their cultural significance beyond just being a fascinating insect.

Conclusion

The floury baker cicada is more than just an interesting insect; it’s a living testament to nature’s ingenuity. From its unique appearance and loud call to its life cycle and interactions with the environment, this genus of cicadas offers a fascinating glimpse into the natural world. The next time you hear that distinctive hissing sound in Australia’s eastern coastline, take a moment to appreciate the beauty and complexity of these creatures.