SURVEY OF THE ENTOMOFAUNA ON THE SOIL SURFACE IN AN ORGANIC APPLE ORCHARD

The ecological aspect of organic farming refers to the ability to maintain the resilience of agroecosystems. This paper aims at investigating the species diversity of entomofauna (harmful and beneficial) on the soil surface in an organic apple orchard under the conditions of ecological management approaches. The organic orchard is located on the land of the village of Vodenichane. Yambol region, Bulgaria. Field surveys of entomofauna on the soil surface in the apple orchard were carried out in 2018 and 2019 with monthly reporting of 'pitfall trap' (soil traps) placed in a checkerboard pattern under the crowns of selecid trees. The Dominance index was higher in 2018 in comparison with the dominance index reported in 2019 and showed the capacity of taxons of higher ecological plasticity to increase their number in return for other taxons in the agrocenosis under survey. The other ecological index is the Equitability index, which expresses the uniformity in the distribution of the total number among the separate species and shows a tendency towards striving for achieving optimal development. Equitability was higher in 2018 as compared to the equitability in 2019, which means that the taxons in the complex were more evenly distributed from a systematic point of view.