NEW DELHI — Nearly 500,000 Indian farmers are facing the prospect of famine as a plague of rats that strikes once every 50 years threatens to destroy their crops, rice paddies, and village granaries.

Efforts to control the rodent plague in the northeastern Indian state of Mizoram have led the local government to offer a reward of about 2 cents for every rat tail delivered to the authorities.

More than 400,000 rats have already been killed, creating piles of tails, which have to be counted by officials before reward money can be disbursed to the catchers.

The rat plague occurs once every 50 years in Mizoram — a state of 900,000 people squeezed between India’s borders with Bangladesh and Burma — and is linked to the flowering of a rare species of bamboo, the Mautam or melocanna baccifera. It flowers all together, dropping millions of protein-rich seeds that are devoured by the rats, causing a population explosion. When the seed supply is exhausted, the rats move to crops and granaries.

The last plague, in 1958–59, provoked a rural uprising that saw the indigenous Mizo people launch a violent 20-year rebellion against the federal government that was only finally resolved in 1986.

The current chief minister of Mizoram, a leading figure of the rebellion called Zoramthanga, is well aware of the potential impact of the famine and is determined that the problems of 50 years ago will not be repeated.

“We are taking all measures to fight the impending Mautam. We are encouraging people to kill rats, we are telling farmers what to do and we are asking Delhi to rush huge additional supplies of food grains to feed our people when the crop shortfalls happens,” he said.

A study by the ministry of forests predicted that 80% of Mizoram’s forested area will be affected by the phenomenon, which was first observed scientifically by the British.