Jorhat, July 19: Army troops deployed in Arunachal Pradesh along the 1,080km Sino-Indian border are having to battle a "secret enemy," a little black fly locally called dim dim (also dam dum).
However, reinforcements are at hand in the form of a herbal repellent.
"We have come up with a herbal repellent, which will not only keep the dim dim away but also other insects common in the jungles of the Northeast," the director of Defence Research Laboratory (DRL), Vijay Veer, told The Telegraph.
The repellent has been tested and will be available for the forces shortly, the director said. A soldier becomes weak and is almost paralysed for several days after being bitten by the fly (scientific name Simulium), which has blinded hundreds in Africa and the US.
The fly's bite causes "black fly fever", with symptoms like headaches, fever, nausea, adenitis, generalised dermatitis and allergic asthma.
The laboratory had begun the research for an antidote to its bite and how to keep the fly away nearly four years ago.
A team from the laboratory had visited Sepa, one of the worst affected areas in the state.
The army has heavy deployment in Arunachal Pradesh, mainly from the Tezpur-headquartered 4 Corps.
An army jawan at Tenga — en route to the border and which hosts a mountain division — said the bite of a dim dim is very painful, unlike the mosquito, and the body itches all over after a few hours. "The itching becomes unbearable," the soldier said.
He said the insect can bite even through a thick layer of clothing.
The laboratory had earlier come up with a herbal vaporiser to deal with mosquitoes. However, this is not of much help as security personnel have to enter deep jungles.
The fly breeds in the water of fast-flowing rivers in the hill areas and feeds on blood.
The laboratory director said the repellent would be available in the form of spray, cream and tissue paper, to be used according to the need.
He said the DRDO is also looking for a partner to market the product so that civilians can use it.
"It will serve a dual purpose," Veer said.
K. Nishing, director of health services (Arunachal Pradesh), told The Telegraph that though the forests of Arunachal Pradesh are infested with the fly, there are no reports of any deaths of humans yet. "It's good news that the DRL has come up with a product which will provide protection against the dam dum menace," he said.
The laboratory has also been working on a project to design "impregnated uniforms" for the troops in the rain forests.
The Northeast has never been an easy terrain for troops, be it guarding the international border or carrying out counter-insurgency-operations, with reports of many of them falling ill after being bitten by such "scary" insects.