Habitat factors influencing the distribution of polyphagous predatory insects between field boundaries

Abstract

SummaryThe winter distributions of a range of polyphagous predators were investigated in relation to field boundary structure. The distribution of Demetrias atricapillus was significantly positively correlated with the density of cocksfoot (Dactylis glomerata) tussocks, and Forficula auricularia and Tachyporus chrysomelinus were significantly positively correlated with percentage cover of deciduous leaf litter, However, although densities of predators varied significantly between field boundaries, no further relationships were identified to explain the observed predator distribution patterns. It is suggested that detailed intensive investigations rather than the extensive approaches of the present study, are required to address questions relating to successful over wintering and selection of over wintering site.

A review of the ecology and conservation of hedgerow invertebrates in Britain

“…Although accurate measures of temperature were not available, drier soils were also implicated as supporting higher numbers of individuals, an association also shown by Sotherton (1985). High abundance of wintering predatory arthropods in hedges was found to be positively associated with amount of leaf litter (Thomas et al, 1992;Maudsley et al, 2000b), which may relate to improved shelter. By contrast, bare ground in field boundaries was found to provide poor overwintering sites (Dennis et al, 1994).…”

A case of habitat complementation in forest pests: Pine processionary moth pupae survive better in open areas

“…Many species living in crop fields and hibernating as larvae are known to move to field margins or adjacent non-crop areas with a permanent vegetation cover. The main mechanism responsible for higher survival in these overwintering habitats is the occurrence of more suitable microclimatic conditions such as milder temperatures (Sotherton, 1985;Dennis et al, 1994) or lower temperature fluctuations (Desender, 1982;Thomas et al, 1992) in winter. In our study we could also relate the better survival of PPM pupae to higher temperatures in the soil of open areas.…”

Summer diet and body condition of Song Thrushes Turdus philomelos in stable and declining farmland populations

“…1999). The loss of mixed farming and the removal and degradation of field margins have also had detrimental effects on farmland beetles (Thomas et al . 1992).…”