the shrill call of the cicada

many people who venture into a tropical rainforest and get assailed by a high-pitch call, tend to attribute it to the cricket. the shrill sound is actually produced by the male cicadas, just as the chirping sounds are made by the male crickets.

male cicadas have loud noisemakers called 'timbals' on the sides of their abdominal base. the cicadas produce sounds by vibrating rapidly the membranes found within its abdomen. they modulate the sounds by moving their abdomens towards and away from the tree trunk.

some cicadas produce sounds louder than 106dB, which is the loudest among insect-produced sounds.

different species have different mating sounds (songs) to attract the mate from the appropriate species. the intensity of the sound also acts as an effective bird repellent. the males tend to gather to create a greater sound intensity to repel avian predators.

(top picture is a cricket; below it, a cicada. the cicada was on a tree at west coast park when i photographed it)