Responses of Grassland Invertebrates to Management by Cutting. II. Heteroptera

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Abstract
Adult Heteroptera were sampled regularly for 3 yr, 1973-1975, from experimental plots of Arrhenatherum-dominated calcareous grassland at Castor Hanglands N.N.R., Cambridgeshire [England, UK]. The experiment, in 4 replicates of 4 randomized block treatments, compared grassland cut in May (M), cut in July (J) and cut in both months (B), with untreated grassland (C). Eighteen species [Acompus rufipes, Stygnocoris pedestris, Tingis ampliata, T. cardui, Nabis ferus, N. flavomarginatus, N. rugosus, Stalia major, Dolichonabis limbatus, Tytthus pygmaeus, Plagiognathus chrysanthemi, Lygus rugulipennis, Phytocoris varipes, Capsus ater, Stenodema laevigatum, Notostira elongata, Megaloceraea recticornis and Leptopterna ferrugata] were sufficiently abundant for statisticaly analysis. The data were pooled for 3 periods of the year: before the May cut (Jan. - May), between cuts (May - July) and after the July cut (July - Dec.). S. pedestris, all species of Nabidae, T. pygmaeus and M. recticornis were severely reduced. Some, especially M. recticornis, were less severely reduced by the May cut than by the July one, whether as a single application or in combination (J and B treatments). The timing of cutting in relation to the life cycles of the different species is important. N. elongata, a double-brooded species, was less susceptible to cutting than other Stenodemini, and L. ferrugata was reduced by the May cut in the period between cuts when most individuals became adult. The effects of cutting are compared with those of other types of grassland management. Timing of cutting and its catastrophic nature compared with grazing are emphasized. Objectives of management and alternative methods of achieving them are considered. Reclamation and maintenance management, single and multiple treatments, rotational, winter and seasonal treatments and the size and kind nature reserves to be managed are discussed.