Time for some intelligence in the war on the cotton bollworm

With Australian help, Indian farmers are fighting back against the world’s worst agricultural pest—the cotton bollworm—which costs $5 billion a year worldwide.

The farmers are reducing the use of insecticides by about a half, while increasing crop yields by 11 per cent and profitability by 75 per cent.

But the bollworm is rapidly evolving resistance to the insecticides. New weapons are needed and researchers say it’s time to design these weapons using the best intelligence available—the genome.

For an investment of only $10 million, agricultural biotechnologists can help farmers turn the tide in the war against this expensive pest.

That’s all it would take, says A/Prof Phil Batterham of Melbourne’s Bio 21 Institute, to unravel the complete genome sequence of the bollworm moth, which infests more than 100 species of agricultural and horticultural crop plants all over the world.

The genome could then be screened to determine what genes make the bollworm resistant to pesticides, and where the pest is most vulnerable to attack. The genetic data could also be used to understand the population structure and track the movements of the bollworm, essential information for planning an effective attack on the insect.

“The bollworm is the number one pest confronting global agriculture,” Batterham told the Agricultural Biotechnology International Conference (ABIC) at the Melbourne Convention Centre.

“You wouldn’t normally go to war against such an enemy without knowing where he’s vulnerable, what his defences are, and who our allies are. But that’s what we do in fighting this pest.”

He says that much of the intelligence we need is contained in the genome sequence.”

Batterham’s research group is acknowledged as a world leader in fighting the pest. Working with the Max Planck Institute in Germany and partners in India, China and France, the group has already been able to identify the genetic basis of resistance to some insecticides. And they can predict where in the genome resistance genes are likely to occur. Batterham announced at ABIC that a particular gene—Dalpha6 confers high level resistance to a widely used insecticide, spinosyn.

The Bio 21 Institute team has been joined by Dr Derek Russell who has spent the past ten years leading a research effort in India, China and Pakistan, specifically aimed at practical measures to reduce insecticide use against the bollworm. In recent years the levels of pesticide employed have been so great they were making cotton growing uneconomic across large parts of Asia, and were affecting the health of farmers.

The research has led to a national control program, now involving more than 1000 field workers all over India. By determining the most effective sprays and times for spraying in different areas and rotating the different sprays to minimise the development of insecticide resistance, the program has reduced the use of insecticides by about a half, while increasing crop yields by 11 per cent and profitability by 75 per cent. The group recently won an award for being the best Indian Government science team.

“We had all the gumboot experience of fighting the bollworm in the field,” says Russell, “but not the laboratory backup we needed, the edge that biotechnology can give us. But we have now joined with what I regard as the strongest molecular science group working on the problem anywhere in the world.”

Batterham and Russell believe that, from their biotechnology intelligence unit, to the research workers, and the network of advisers working with farmers, they have made great strides in the war against the bollworm. But much more could be achieved if they could design a new generation of weapons using the genome sequence of the bollworm.