The agricultural gain by Bt cotton farmers seems to be at the cost of other ryots. The bollworm, which used to feed on cotton before the Bt variety was introduced, has now found new hosts for survival

By Syed Akbar
Hyderabad: The agricultural gain by Bt cotton farmers seems
to be at the cost of other ryots. The bollworm, which used to feed on
cotton before the Bt variety was introduced, has now found new hosts
for survival.

Bt cotton is poisonous for the cotton bollworm and it cannot survive
on its leaves. To avoid death in Bt cotton fields, the insect, which
belongs to the butterfly family, has cleverly migrated to new plant
hosts for survival.

The bollworm is now attacking crops like tomato, pigeon pea, chickpea,
sorghum and maize. The agricultural loss, which cotton growers
suffered earlier, has shifted to farmers growing food crops. This has
led to increase in use of pesticides by non-Bt cotton farmers to
reduce the additional loss.

“Cotton bollworm has about a dozen plant hosts including the wild
varieties. The mother insect is a long flier and in the absence of
cotton, it lays eggs on new plant hosts for its larvae to feed on. It
is a smart insect and its survival tactics has led it away from
poisonous Bt cotton to non-poisonous plant varieties grown in the
vicinity,” said senior researcher MA Qayyum.

There are no reports of reduction in the population of cotton bollworm
and this indicates that it has adapted to non-bt cotton crops to lay
eggs and populate its species.

There have been no scientific studies on the additional loss to
farmers growing other crops. However, field observations show that the
shifting of bollworm from Bt cotton to food crops has resulted in
farmers losing at least 20 per cent of their yields. Thanks to the
pest migration, the bollworm has found a continuous life, from one
season to other, pointed out Qayyum, who had conducted field research
studies on Bt cotton for about a decade now.

Dr PV Satheesh, national convenor of Southern Action on Genetic
Engineering, said given the choice between cotton and red gram, the
bollworm prefers red gram. “If you control the pest using Bt
technology, it will find new sources of food for survival. We have to
access the damage caused to other crops with the shift in plant
hosts,” he added.

Red gram seems to be the most affected crop with the shift in pest’s
preference. Earlier, farmers used to grow a few layers of red gram
plantation along with cotton to detract the attention of bollworm from
cotton to red gram. Farmers stopped this practice after the
introduction of Bt cotton. Red gram once served as a “trap crop” for
cotton farmers, but now it has turned into a target crop by the
bollworm.