Resting site selection in the geometrid moth Phigalia pilosaria (Lepidoptera: Geometridae)

When tested in a cylindrical apparatus, males of both typical and melanic morphs of the nocturnal moth Phigalia pilosaria (Schiffermueller) prefer to rest on light backgrounds. This preference is more pronounced when the moths have a rough surface on which to rest than when it is smooth. The two morphs show a distinct tendency to adopt resting positions close to the boundary between the shades presented in the experiments; this is interpreted as being a result of walking moths stopping at or close to the boundary when approaching it from the light side. The surface texture of the background influences the resting attitude of the moths in relation to vertical.