Changing dynamics of the pine beauty moth (Panolis flammea) in Britain:: the loss of enemy free space?

1 The pine beauty moth Panolis flammea has two main host plants in Britain: Pinus sylvestris (Scots pine), which is the ancestral food plant where the insect is never abundant enough to cause tree mortality, and Pinus contorta (lodgepole pine), an introduced host tree that has experienced periodic widespread tree mortality due to this pest. 2 We review the recent literature, published mostly after the year 2000, regarding the impact of natural enemies on the population dynamics of P. flammea in Britain. 3 The natural enemies of P. flammea are more diverse and abundant in Scots pine habitat than in lodgepole pine habitat and some of them show differential selection for P. flammea larvae in Scots pine habitat over those located in lodgepole pine habitat. 4 It is concluded that the difference in the population dynamics of this insect in the two different habitats was probably the result of the P. flammea finding enemy-free space in lodgepole pine habitat. 5 Recent evidence on the diversity and impact of natural enemies on lodgepole pine has demonstrated that they currently have a much more significant impact on this pest than they did in the 1970s and 1980s, when outbreaks were frequent.