Cicadas: Summer’s Big Bug

Outdoors in the Land O'Lakes by Steve Blight

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Ahhhhh, the dog-days of summer.  The afternoons are long, the light is golden, and the cicadas are singing in the treetops. In North America, there are a large number of cicada species, most of which are classified under two groups: the annual or “dog-day” cicadas, and the periodic cicadas.  The periodic cicadas are generally better known because of their long life cycles of 13-17 years, and their emergence in enormous numbers during a “cicada year”.  However, these cicadas are much more common well to the south of our area in the United States.  In fact, the periodic group likely does not occur at all in the Land O’Lakes area.  The common cicadas of our area belong to the dog-day group.  They are called this because they emerge every year during mid to late summer, the period also known as the dog-days of summer.

Cicadas are big bugs – and this is true for a couple of reasons.  First, there are very few insects in our area that rival cicadas for sheer size.  They are about 5 cm long, robust and somewhat triangular in shape.  No doubt they would make a very satisfying meal for a foraging songbird!  Second, they collectively belong to an order of insects called “Homoptera”, a group which comprises around 80,000 species of cicadas, leafhoppers, shield bugs and others, and are collectively known as – wait for it – the “true bugs”.

Cicadas are well known for their loud, high-pitched, shrill call. The sound is produced by the male, which has powerful muscles attached to the side of membranes that can be vibrated very rapidly. This droning sound is produced on hot, humid days in July and August.  Cicada’s antennae are very short, and generally range from brown and green to black in colour.  The wings are held over the back in a sloping fashion and are transparent.  Cicadas are considered by many people to be unusual and attractive – for insects, that is.  In some cultures, particularly in Asia, cicadas are kept as noisy but short-lived pets.

Eggs are laid in the twigs and small branches of trees. The female deposits 10 to 20 eggs in a puncture beneath the bark. Upon hatching, the nymphs drop to the ground and burrow into the soil. They form a small chamber in the soil near a tree rootlet from which they suck the sap.  Nymphs develop very slowly, taking 4 years or more until they are ready to become adults.  If you are lucky, you may see them transform from a nymph to an adult.  When the nymphs are full grown, they crawl out of the soil and up a tree trunk to a place where they grasp the bark firmly.  Similar to the way a dragonfly transforms, the skin splits down the middle of the back and the adult gradually works its way out.  They remain near the old cast skin until the body and wings harden and they are ready to fly.  Adults live for a few weeks at best – just long enough to enjoy a few warm days, find a mate and create the next generation of cicadas to serenade us during those long, hot dog-days of summer in the Land O’Lakes region.

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Please feel free to report any observations to to Steve Blight at natureobservations@rogers.com or Lorraine Julien at outdoor1@look.ca