The cicadas are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). Cicadas have prominent eyes set wide apart, short antennae, and membranous front wings. They have an exceptionally loud song, produced in most species by the rapid buckling and unbuckling of drum-like tymbals. One exclusively North American genus, Magicicada (the periodical cicadas), which spend most of their lives as underground nymphs, emerge in predictable intervals of 13 or 17 years, depending on the species and the location. The unusual duration and synchronization of their emergence may reduce the number of cicadas lost to predation, both by making them a less reliably available prey (so that any predator that evolved to depend on cicadas for sustenance might starve waiting for their emergence), and by emerging in such huge numbers that they will satiate any remaining predators before losing enough of their number to threaten their survival as a species.
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進階授權 | 2828 x 4242 px | JPG | 88 點 |
進階授權 | 2828 x 4242 px | JPG | 88 點 |