TY - JOUR T1 - Habitat management in winter wheat and evaluation of subsequent spider predation on insect pests JF - Acta Oecologica Y1 - 1995 A1 - Jmhasly, Patrick A1 - Nentwig, Wolfgang SP - 389 EP - 403 KW - [Arachnid predators / / Araneae KW - [Cultivated land habitat / / ] [Switzerland / / Berne KW - [Population size / / Web cover] [Cultivated land habitat / / ] KW - [Switzerland / / Berne KW - Animals and man KW - Arachnida KW - Araneae (Arachnida): [Predator]. KW - Araneae [Farming and agriculture / / Wheat KW - Commercial activities KW - Diet KW - Disturbance by man KW - Ecology KW - ecology & predation] [Insect prey / / Wheat field KW - effects on predation] [Population density / / strip management effects] KW - Eurasia KW - Europe KW - Habitat KW - Insecta (Arthropoda): [Prey]. KW - Insecta [Farming and agriculture / / Wheat field KW - Land zones KW - Man made KW - Nutrition KW - Palaearctic region KW - Population dynamics KW - predation by KW - Predators KW - Prey KW - strip management KW - strip management effects on KW - strip management effects on predation] KW - strip management effects] [Population regulation / / ] KW - Zollikofen]. AB - Density estimates, web cover and predatory importance of different spider families were investigated over one field season in relation to habitat manipulation by strip-management in a winter wheat field at Zollikofen near Berne, Switzerland. Spider densities and web cover were in most cases higher near the sown weed strips than they were away from them. The strips contained a significantly greater web cover for the sheet webs of Linyphiidae in May and at the end of July. Qualitative assessment of spiders' prey revealed high percentages (up to 92%) of Diptera and Aphidina (including pests). Quantitative evaluation of spider predation in the orb webs of Araneidae/Tetragnathidae and the sheet webs of Linyphiidae showed very small prey turnover rates e.g. Linyphiidae killed on average 1.5-1.7 aphids m-2 9 h daylight-1 in wheat. Theoretical estimates of diurnal prey capture in all spider webs (including Theridiidae and Agelenidae) were calculated. Comparisons with the reduction of noxious insects by other polyphagous predators suggested that in the investigated field the importance of spiders as biological control agents is rather small. VL - 16 SN - 1146-609X UR - ://ZOOREC:ZOOR13300002246 N1 - ZOOR13300002246 ER -