By Don Lawrence

In the height of Toronto heat, a droning buzz permeates the Centennial community. While it may be often thought that the sound is from grasshoppers or crickets, it’s really the Dog-Day Cicada, appropriately named to remind us we’re in the thick of the dog days of summer.

These cicadas are among nature’s unique creatures. Special organs generate the loudest mating call sound of all insects. The sound comes from two elastic, circular membranes (timbals) affected by the contraction and relaxation of the large timbal muscle. Rapid repetition of this action produces the seemingly continuous sound of the male chorus.

A cicada’s life cycle starts with the female implanting her eggs in a woody plant. After hatching, infant cicadas (nymphs) drop to the ground and with their strong front legs, burrow underground. They spend one to three years feeding underground on the juices of plant roots. When the growth stages are completed and the ground hits a certain nighttime temperature, millions of insects come to the surface.

This year’s cohort will hatch and attach to a nearby plant, shed their skins (molting), and emerge as fully formed adults. Due to their camouflaging hues of green, brown, and black, it’s rare to see an adult, but a close look might reveal their shed exoskeletons clinging to trees or bushes.

Their body size is typically 27–33 mm, while the wingspan can reach 82 mm. Cicada wings are interlaced with green veins that are especially noticeable near the base. Some southern cicada species spend up to 17 years underground. According to the one-to-three-year cycle, one cohort of our northern Dog-Day Cicada appears each year.

During the cicada’s life above ground, all energy is put into finding a mate, breeding and laying eggs. The male’s life consists primarily of singing, flying and mating. The four-to-six-week lifespan may be short, but it’s full of sex. The female creates slits in branches, then deposits her roughly 500 eggs. She then falls off the branch and dies. Males might live a few days longer. The cicada life cycle now begins anew.