Indian researchers discover virus to save tea crops

Inidan plant scientists have discovered a virus which can destroy black loopers (Hyposidra talaca) responsible for loss of around 40 per cent tea crops every year. The researchers of North Bengal Regional R&D Centre of Tea Research Association, the only institute in northern India that researches on tea, have found that Nucleo Polyhedro Virus (NPV), which belongs to Baculoviridae family, is very active in infecting tea loopers under field conditions.

Deputy Director of Tea Research Association Azariah Babu said the black looper pest has been a serious concern for tea farmers since 2008. “Since the croppers in the north-eastern region were suffering from considerable amount of crop loss due to the insect, we decided to find out a long term non-chemical control strategy,” he said.When the researchers studied the tea echo-system, they found that there is a virus that is infecting the insect. They then decided to start a collaborative project with Kerala-based SciGenome Research Foundation (SGRF) to find out the virus, which accounts for 20 to 30 per cent of natural control of tea echo-system during three months duration.

“We collected the NPV infected insects from the field and did the whole genome sequencing of that particular micro-organism. We found that it has no harmful effect on other organisms and other pests also. It is species-specific. We reared the insects with the help of artificial diets for culture of the virus and came out successful. It is a breakthrough,” said Babu, who was here recently to attend an international conference on genomics.

The scientists have decided to produce the virus commercially and use it as bio-pesticide. As tea is an export commodity and it is affected by pesticide residues, they want to make it free from chemicals. With the help of SGRF, they have developed a technology for formulation of the bio-pesticide.

“Pilot phase production has been done and it is field tested. The result showed that after 144-168 hours of spraying, larvae were infected by the NPV and 100 per cent mortality was recorded. We are hopeful of registering the product under Central Insecticide Board for its regular use of pest management in tea. We have a target to start its commercial production by 2019. It will be a boost to the tea industry since we are looking for non-chemical control of pests,” Babu added.