19k trees slated for felling amid beetle larvae infestation

Dehradun: Nearly 19,000 trees in Dehradun have been identified for felling after these were infested with Hoplocerambyx spinicornis larvae, commonly known as the sal borer beetle, according to the Uttarakhand forest department.

The secondary assessment, conducted by the Forest Research Institute (FRI) at the request of the forest dept, classified infestation levels on a scale of one to eight. Scientists said trees falling in categories one and two are effectively dead and need to be removed. A majority of the affected trees are in Jhajhra, Thano and Asharori—areas that are also slated for extensive road widening.

Dehradun DFO Neeraj Sharma said the sal heartwood borer is not a new threat. “The sal trees (Shorea robusta) of Dehradun have seen such infestation by sal borers in the past too. The beetle has co-evolved with the sal trees.” He added that further action will be taken after obtaining clearance from the Union ministry.

However, forest ecologists have raised concerns over the scale of the proposed felling, calling for a broader and more sustainable approach. “Urban landscapes cannot be carbon emitters, and it is time that a nationwide urban forestry plan be implemented with legal binding,” said SP Singh, Fellow of the Indian National Science Academy (INSA) and noted Himalayan ecologist. He suggested exploring alternatives such as insecticide treatment and medicinal injections — methods used in other countries — before ordering large-scale tree removal.

To control the outbreak, a trap tree operation will be planned in May and June, just ahead of the monsoon, subject to necessary approvals, according to Sharma. The dark brown insect typically undergoes hibernation during Nov and Dec.

Entomologists attributed the infestation to multiple factors, including the prolonged monsoon last year and increasing disturbance in forest landscapes due to lopping, timber collection and other human activities. “Extended monsoon last year, followed by a changing landscape of forests that is disturbed in multiple ways, be it lopping, timber collection, or other associated reasons,” they said.

Road widening and other developmental activities are currently taking place in the affected areas, which experts believe may have further contributed to ecological imbalance.