A cicada’s life cycle involves a dramatic transformation, culminating in the shedding of its nymphal skin, a process known as ecdysis or molting. This event marks the insect’s transition from a subterranean juvenile to a winged, reproductive adult. While cicadas spend years underground as nymphs, the visible molting process occurs relatively quickly. The total time required involves a sequence of distinct periods: preparation, the physical shed, and subsequent hardening. This transformation prepares the insect for its brief adult life above ground.
Preparing for the Final Shed
The final molting process begins when the mature nymph emerges from the soil, typically after the ground temperature reaches approximately 64 degrees Fahrenheit. The nymph immediately seeks a vertical surface, such as a tree trunk or sturdy plant stem, to carry out the process. Finding a suitable anchor point is required for a successful molt, and the nymph uses its strong claws to secure itself firmly to the surface. Once secured, the nymph remains still, sometimes for an hour or more, preparing internally for the strain of breaking free from its rigid outer shell.
The Visible Ecdysis Process
The visible ecdysis begins when the exoskeleton splits down the nymph’s back along the dorsal midline. This split occurs due to increased hemolymph pressure, which forces the body to expand and fracture the old cuticle. The physical shedding, from the initial split to the adult cicada completely extracting itself, typically takes between one and two hours, though it can sometimes be completed in as little as 30 minutes.
The head and thorax are the first parts to emerge, with the cicada hanging upside down from the split shell, allowing gravity to assist the process. The insect then rights itself by grasping the shed shell with its newly freed legs before slowly pulling the abdomen free from the casing.
The Vulnerable Hardening Period
Immediately after freeing itself, the adult cicada enters the teneral stage, appearing soft, pale, and defenseless. The cicada must remain attached to its anchor point while it pumps hemolymph into its crumpled wings to expand them fully, a process that takes a few hours.
The full hardening and darkening of the new exoskeleton, a chemical process called sclerotization, takes much longer. The cicada must wait several hours, often four to six hours, for its body to become firm enough to move and fly effectively. Full adult coloration and hardness can take up to a day or more, during which the teneral cicada is extremely vulnerable to predators.