by Sriraksha Bhagavan –For most animal species on earth, males often have to compete to get a female. For species living in a social community, finding a mate is easy than compared to solitary ones. Each kind of species has found a way to communicate and find its own species-specific mate through different modes, be it either color display or pheromones or dance or by just by signing a song.
Among the insects, one of the noisiest mating calls are made by Cicada males. For those of us who have heard them singing one would relate it to the sound of a moving motorcycle without an exhaust and would be really unpleasant and irritating when you are surrounded by thousands of them.
To attract a female, a group of males sit on the tree bark and sing loudly in chorus by vibrating their drum like tymbals which can be heard several kilometers away. A female will then fly to the noisiest male and will respond to him by making a click-like noise and then they mate. The female would deposit her eggs on the tree bark or twigs, the young nymphs hatch out of the eggs and fall on the ground, the nymphs burrow deep inside the soil and suck liquid from the plant roots and undergo several molts during their growth.Some of the adult Cicadas emerge annually during June- July and some are known to emerge periodically with several broods with an interval of 13 to 17 years (Magicicada, commonly found in the US).
No one really knows why these cicadas wait for 13 to 17 years to emerge. Many Scientists have hypothesized that one reason why these Cicadas emerge once in 13 or 17 years is because 13 and 17 are relatively large prime numbers (relative to the average lifespan of an animal) and thus its difficult for predators to synchronize with them. And to support this hypothesis, scientists have found several wasp species to have specialized to predate on annual cicadas whereas periodical cicadas have no such wasps because no wasp has evolved to synchronize with such long life cycle. Sounds crazy, think about it!!
Here the sound of the cicada below: