Quantifying food limitation of arthropod predators in the field |
| |
Authors: | Trine Bilde Søren Toft |
| |
Institution: | Department of Zoology, University of Aarhus, Building 135, DK-8000 ?rhus C, Denmark e-mail: trine.bilde@biology.aau.dk, DK
|
| |
Abstract: | A method for quantifying food limitation of arthropod predators in the field is presented and applied to species of ground
beetles (Carabidae) and sheet-web spiders (Linyphiidae) from a cereal field. Food limitation is expressed quantitatively as
accumulated hunger (=starvation) by transforming 24-h food consumption at 20°C of animals newly collected in the field into
days of starvation at 20°C. This is done by means of a reference curve relating 24-h food intake at 20°C to starvation periods
(days) at 20°C. Such a reference curve was obtained for the carabid beetle Agonum dorsale in the laboratory. For other species the reference curve was modified with species-specific data. The procedure makes it
possible to compare the feeding conditions of different species populations that are part of the same community. Hunger levels
in the field for females of A.␣dorsale were equivalent to c. 15 days of starvation in early spring, c. 5 days in June, increasing to c. 10 days in late summer. Two ground beetles occurring during summer also showed increasing hunger levels from June to July,
probably the result of a dry summer. Two spider species experienced a hunger level in the range of 4–8 days of starvation.
Received: 15 August 1997 / Accepted: 22 January 1998 |
| |
Keywords: | Ground beetles Linyphiid spiders Food consumption Starvation |
本文献已被 SpringerLink 等数据库收录! |
|