“…Value would also be lost because of reduced wool 'quality'. 'Quality' is difficult to assess, but has been shown, on the basis of subjective assessment, to be adversely affected by sheep lice (Kettle & Pearce 1974). In addition, 2 aspects of 'quality' which can be accurately measured using scoured woolyellowness and lightness -are both detrimentally affected by lice (Kettle & Lukies 1982b).…”