The World Cup cicada: India’s rare insect on a four-year clock

The final journey

"By mid-June it is over," Evansis says.

The mature cicadas, dark-shelled and spent, begin flying towards the Umrong River in large numbers and drop into the rapids. The river fills with them. Along the banks, dead cicadas collect against wet stones and bamboo roots, their wings plastered flat by the current.

Locals c...