The feeding behaviour of Alpine Grasshoppers (Acrididae : Orthoptera), in the Craigieburn Range, Canterbury, New Zealand

Insects have only recently been implicated in the deterioration of New Zealand alpine grassland vegetation. Among the most prominent of these insects are alpine grasshoppers. The most important aspect of this study was a determination of the diet of grasshoppers, to ascertain if feeding pressure could be exerted on particular components of the vegetation, as a result of the plant species selected. This involved the determination of diet in relation to the associated vegetation. To this end, grasshopper diet was largely determined from the analysis of gut contents, and vegetation was assessed by the point analysis method. The main bulk of field work was carried out in a study area in the Craigieburn Range, Canterbury, during the summer of 1968/69. A secondary aim was also facilitated from the diet determinations. An investigation of the degree of food specialization between the four grasshopper species concerned, whose feeding ranges overlap, enabled some indication of the possible extent to which intraspecific competition for food was present