The Humble Cicada

Cicadas are an interesting insect. Adults are typically between 1 and 2 inches long while some tropical species can reach 6 inches in length. Worldwide there are about 3,000 species; nearly all of them have their own distinct song. The songs are produced by structures, located on each side of the abdominal segment, called tymbals. The tymbals are ribbed membranes with muscles that are used to contract the membrane inward producing the distinctive click of the cicada. As the membrane expands back another click is produced. Each membranes alternately contracts. To amplify the songs the male has a hollow, air-filled abdominal cavity. Interested females respond to the songs with wing flicks that produces a sound similar to snapping one’s fingers. 

When a pair has mated the female will deposit her eggs in branches with her ovipositor, laying up to several hundred eggs at a time. When the eggs hatch the nymphs will burrow into the ground to live out their juvenile lives. Most species will spend two to five years underground sucking the xylem from the roots of trees. However, some species such as the Magicicada, known as periodical, will spend 13 or 17 years underground before emerging.

Periodical cicadas have five distinct juvenile stages before they are ready to leave their burrows. When they are ready to leave the ground the nymphs will begin digging tunnels to the surface and at night they will climb up trees en masse to molt and reveal their transparent and delicate wings. Adults will live only a few weeks to a month starting the cycle all over again.