Intro: For the first time Biston regalis Moore appreared in epidemic form in the blue pine (Pinus wallichiana) forests of Murree and Azad Kashmir in August, 1980, causing defoliation over about 3175 acres. The insect has an annual life cycle with moths emerging in May. These have brownish grey wings with thick black and white strips, exhibiting close mimicry with tree trunks. They hide under plant debris during day and become active at dusk and dawn. Moths spend the night sitting on tree trunks and on fresh needles.