GUWAHATI, Sept 15 - The pest invasion on paddy fields that have hit 22 districts in an unprecedented manner is largely attributable to aberrations in climatic conditions besides changes in traditional agricultural practices.
Agri-scientists are also worried that unless the eggs of the pest are destroyed, there is every possibility that the affected areas could become endemic to the menace. Sources in the Agriculture Department quoting agri-scientists told The Assam Tribune that the rice swarming caterpillar – a rapidly breeding variety and a voracious eater of plants – found the conditions in the form of rains and high temperature after the last wave of floods ideal for proliferating.
A single butterfly can lay up to 400 eggs, triggering rapid multiplication of the worm.
“This pest has always had some presence in our paddy fields but such large-scale invasion has been seen after nearly 50 years. The unusual climatic conditions have favoured the pest, which takes shelter on the narrow earthen bunds crisscrossing the paddy fields. The rains and high temperatures following the monsoons have helped it breed rapidly and spread to wider areas in quick time,” sources said.
What has added to the favourable conditions to the swarming caterpillar – also called Armyworm because of its systematic and disciplined raids – is that with the gradual shifting to mechanized farming, croplands no longer undergo the practices associated with manual farming such as laddering and mud-plastering of the bunds – practices that worked against the pest’s survival.
“Earlier, there used to be some interval between the tilling of the land and the sowing of seeds, allowing enough sunshine on the earth.
Similarly, farmers used to mud-plaster the bunds, resulting in the death of the worms,” sources added.
The caterpillar, which is a nocturnal occupant, devours one plot systematically before invading the nearby plot. It starts eating from the side of the leaf blade and leaves only the mid-reed or vein besides cutting the panicle at the root.
According to agri-scientists, controlling the pest is not a complex affair and there is no reason to panic. But, at the same time, it needs to be ensured that not just the worms but their eggs, too, are destroyed for preventing recurrence of their invasion. “Otherwise, the affected areas can become endemic to the pest,” sources said.