The wart-biter, Decticus verrucivorus (L.), in the United Kingdom; a comparison of sampling methods

The wart-biter, Decticus verrucivorus (L.) (Tettigoniidae), is rare in the United Kingdom and has been the subject of field studies to identify its habitat requirements and establish a monitoring programme for remaining populations. The main technique used has been a simple walk-survey method carried out on permanently marked transects. This article summarises the lessons learnt and presents a rationale for using walk-surveys, in combination with a range of alternative methods, as a basis for estimating the distribution, density and size of wart-biter populations. Unpublished data, including from walk-surveys and a preliminary mark-recapture study, are presented. The article concludes with a list of recommendations for the survey of Decticus populations which may have relevance to studies of other ground-dwelling Orthoptera.