Ground beetles (Col., Carabidae) are common predators in agrocenoses. A number of plant pests occurring on arable fields become their feed. Therefore, they contribute to a natural reduction of the occurrence of pests. In addition, they are well-known bioindicators used, among others to determine the state of the habitats and the impact of human activity on entomofauna. In the fields, the use of chemical plant protection products is a very controversial activity. The aim of the study was to investigate assemblages of ground beetles occupying conventional and organic sugar beetroot crops. Therefore, to determine the impact of the application of pesticides on the assemblages of these useful beetles was made. The study was conducted at the Agricultural Experimental Station in Winna Góra near Środa Wielkopolska in Poland from May till September of 2004, 2008, 2012 and 2016. The experiment was carried out in the field with organic crop of sugar beet, and in the crop, for which an integrated plant protection programme was planned. The area of each field was 0.5 ha. Modified Barber traps were used to catch insects. On each of the selected fields 10 pitfalls were set up, which were emptied every 14 days. Within 4 years of the study a total of 11865 specimens belonging to 52 ground beetle species were recorded. 5582 specimens belonging to 50 species and 6283 specimens belonging to 46 species were caught in the fields under chemical protection and organic, respectively. On a multiannual scale, there were no statistically significant differences in the number of individuals and species of Carabidae on conventional and organic fields. Fluctuation in ground beetles abundance and species richness were observed dependent on the year of study but not of the treatment. Harpalus rufipes was the most represented species in all fields. The main conclusion is that using chemical plant protection on a multiannual scale does not adversely affect the number and species richness of ground beetles.

Maintaining biodiversity is one of the factors determining the proper functioning of ecosystems, especially those with high human impact. Ground beetles, as bioindicators, are particularly valuable in understanding ecosystem responses and sustainability in forest and landscape management. Focusing on the regeneration of pine forests, this study aimed to describe ground beetle assemblages on Scots pine natural and artificial regeneration in northeastern Poland. This study was conducted between 2016 and 2018. Pitfall traps were set up for catching epigeic carabids on previously prepared research plots designated for natural and artificial pine regeneration. The research areas included three variants: N—natural pine regeneration, plots without soil preparation; NP—natural pine regeneration with traditional soil preparation by ploughing; and A—artificial pine regeneration with ploughing. Four plots as replicants were selected in each experimental variant, with six pitfall traps in the transects running through the centre of each study plot. In each year of the study, 11 samples were collected from each plot; overall, 33 samples per plot were collected during the three years. As a result of this study, 26,654 ground beetle individuals belonging to 89 species were caught during the three-year observation. Natural regeneration without soil preparation (N) was the most favourable in terms of the occurrence of stabilised assemblages of ground beetles. However, the remaining methods of pine regeneration, on a multi-annual scale (2016–2018), contributed to the increase in the number of ground beetles but also provided high variability in assemblage composition, diversity indices, and life-history traits. Thus, in the early stage of pine regeneration, each of the examined variants of pine regeneration can be used without fear of causing damage to carabid populations. However, further studies are required to investigate the effect of different pine regeneration types on carabid beetle assemblages over a longer period.