Aleeta - Life Cycle

Life Cycle

Eggs are laid in a series of slits usually cut in live branches or twigs of their food plants by the mother's ovipositor. On average about 16 eggs are laid in each slit, among a total batch of a few hundred. The batch all hatch within a day or two of one another around 70 days later, but take longer in cold or dry conditions. Oviposition (egg-laying) has been observed on a very wide range of native and introduced plant species, and can weaken the branches of young orchard trees such that they cannot later sustain the load of their fruit.

After hatching, the nymphs of all cicadas fall to the ground and find a crack in the soil which they burrow down to a depth of 10–40 cm (4–16 in), digging with their large forelegs. Larger species of cicada like A. curvicosta are thought to spend 2–8 years underground, growing and feeding through their rostrum on the sap from tree roots, moulting five times, before emerging from the ground to shed their final shell. Emergence consistently occurs at night, but the emergence of the population is diffusely spread over the season in comparison to the more high-density Australian species. The sex ratio is about 1.15 males to every female, consistent throughout the emergence. The metabolic rate over a period of about 6.5 hours during emergence of A. curvicosta is about 1.8 times the resting metabolic rate of the adult. A South-East Queensland study reported nymphs would emerge on most tree species but avoid Norfolk pine (Araucaria heterophylla) and broad-leaved paperbark. The adults are usually found between November and May, but are sometimes observed from as early as September until as late as June. They were recorded as appearing every year, mainly in December and January in western Sydney, with a similar 92 day emergence period from late November until late February recorded in South-East Queensland. The nymph grips onto the tree bark with all of its legs, swallows air and redistributes haemolymph to split the cast down the center of its back. It then extracts its head and clypeus by hunching its body, and when they are out, arches back to draw the legs out of their casing. It then slowly unfolds its wings, finally bending forward and gripping onto the front of the shell to free its abdomen. Once free it hangs for hours more as the wings harden.

Most cicada species then live as adults for about two to four weeks when mating and egglaying occurs.