Echos of Vietnam?

News that English Nature is to attempt to tackle the possible infestation of woods around Pangbourne with Oak processionary moth (Thaumetopoea processionea) larvae by two bouts of spraying insecticides incorporating Bacillus thuringiensis is redolent of the spraying of Vietnamese forests with Agent Orange in the infamous Asian war (http://www.guardian.co.uk/environment/2013/may/06/pest-caterpillars-helicopter-blitz-insecticide)! The action is a bit contentious. The larvae certainly denude Oak trees and their irritating hairs (a defence mechanism used by the moth) can cause skin and breathing problems in people and their pets but the woods are home to rare and important populations of butterflies and moths that could also be eradicated by the treatment. The claim is that the Oak processionary moth outbreaks are difficult to detect in woodlands (are they there or not?) but personally I would like to see more of a ground based attempt to focus treatments.