Dog-day cicada

Only the males sing, making a loud high-pitched sound something like a circular saw and lasting about 15 seconds. Their singing is associated with hot summer days. It starts out soft, gets louder and then fades away. In addition to their characteristic song, cicadas can make a squawk when handled.

The song is produced by a pair of tymbals located on the sides of the first abdominal segment, under the folded wings. The rapid contraction of the muscles deforms the tymbals, which produce the sound as they flex. The sound is amplified by air sacs on the male’s abdomen that serve as resonance chambers.

Cicadas are able to hear thanks to the tympanal organs also located on their abdomen, near the tymbals. This highly developed hearing organ may be blocked by releasing a muscle, allowing the insect to sing without being disturbed by loud noises nearby.

Adult dog-day cicadas appear every three years in overlapping annual cycles, in contrast with so-called “periodical” cicadas (Magicicada spp.), which emerge in huge numbers in 13- or 17-year cycles.

While some authors claim that these insects are harmless, they have been reported to bite when handled clumsily, so caution is advised.