Factors Affecting the Abundance of Shoot-Files (Diptera) in Grassland

A study of the economic importance of the dipterous shoot-flies in Northern Ireland grassland was undertaken from 1967 to 1972. This comprised several experiments to determine the effect of overwintering shoot-fly larvae on grass growth, the distribution of shoot-flies on the farm where these experiments were carried out and the prevalence of shoot-flies in grassland throughout a wide area of Northern Ireland. The study involved the examination of many swards of different botanical composition under different management systems and in different environments and the effect of these factors on the distribution of shoot-flies is described below.