Impact of environmental conditions and agro-technical factors on ground beetle populations in arable crops

Abstract

Ground beetles (Coleoptera: Carabidae) are the largest family of adephagan beetles. Their role in natural pest control is important due to their predatory polyphagous nutrition and bioindicative value since they are sensitive to environmental and anthropogenic changes. Therefore, the main objectives were to understand how common arable cropping systems in Croatia affect ground beetles abundance in respect to the environmental conditions. We hypothesized that environmental specifics (soil type and structure, climatic conditions) together with cultivation measures (tillage and insecticide application) would affect ground beetle activity and abundance. The research was conducted in two locations Lukač, Virovitica – Podravina County and Tovarnik, Vukovar – Sirmium County. Ground beetles were collected weekly, from May to September 2015, by epigeic pitfall traps and endogeic perforated probes from fields sown with typical arable crops in these areas. In total, 2,582 ground beetle individuals were collected using epigeic traps, and 323 ground beetles were collected using endogeic traps. Significantly lower ground beetle abundance has been recorded in Tovarnik than in Lukač. The crop and cropping history affect the abundance through modification of environmental conditions (soil characteristics, microclimate factors such as temperature and humidity), as well as trough disturbance factors such as tillage schedules and harvest/sowing schedules.