Applied Soil Ecology 23 (2003) 111–117 Effects of groundcover management on ground beetles (Coleoptera: Carabidae) in an apple orchard M. Miñarro ∗ , E. Dapena Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Apdo. 13, 33300 Villaviciosa, Asturies, Spain Received 3 May 2002; received in revised form 17 February 2003; accepted 20 February 2003 Abstract A field experiment was conducted in a cider-apple orchard to evaluate the effect of six groundcover management systems (pine-bark, plastic and straw mulches, tillage, herbicide and natural soil) on the occurrence of ground beetles (Coleoptera: Carabidae). Eight species of carabids were collected in pitfall traps. The three most common beetles, Steropus gallega Fairmaire (65.8%), Pseudophonus rufipes (DeGeer) (18.2%) and Poecilus cupreus L. (14.6%), represented more than 98% of the total catches. The specific dominance depended on the sampling date. The soil management treatment significantly affected the following parameters. (1) The overall carabid catch: the plastic mulch (5.6% of the total catches) negatively affected total carabid collection, which was higher in the tilled (24.3%) and herbicide-treated (21.4%) plots, although not significantly different from the natural soil (16.5%), straw mulch (16.3%) and pine-bark mulch (15.9%) treatments. (2) The specific preferences of the three most common carabids: the plastic cover adversely affected the catches of S. gallega whilst P. rufipes was collected in greater numbers in tilled areas and P. cupreus in the herbicide treatments. (3) The structure of the carabid community: based on species richness, diversity and evenness indices, herbicide and tillage provided the most diverse carabid community and the straw mulch the poorest. It was concluded that groundcover management in apple orchards may affect the activity density of epigeic predators which may contribute to the natural control of pests. © 2003 Elsevier Science B.V. All rights reserved. Keywords: Carabid beetles; Agronomic practice; Orchard management; Diversity; Biological control 1. Introduction The control of weeds in the first few years after planting is of critical importance for the satisfactory development of an orchard. Correct groundcover man- agement is necessary to reduce competition for water and nutrients. Each agronomic practice used to control weeds has its advantages and disadvantages, result- ing in differences in tree growth and fruit production ∗ Corresponding author. Tel.: +34-9858-90066; fax: +34-9858-91854. E-mail address: mminarro@serida.org (M. Miñarro). (Merwin and Stiles, 1994; Utkhede and Hogue, 1998), nutrient supply and uptake (Merwin and Stiles, 1994) as well as in the management of diseases and pests, such as crown and root rot infection (Utkhede and Hogue, 1998) or vole damage (Sullivan et al., 1998; Merwin et al., 1999). The disturbance of the soil structure produced by agricultural practices has a considerable influence on the abundance and diversity of the epigeic fauna (e.g. House and Alzugaray, 1989). Carabids, which are especially sensitive to habitat alteration, have been commonly used as a model to study the impact of groundcover management practices on the occur- 0929-1393/03/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0929-1393(03)00025-8