Agricultural Management Greatly Affects the Beneficial Entomofauna of the Olive Groves

Abstract

In the course of the last decades there has been a remarkable evolution in the agricultural practices carried out in olive growing, from a conventional management (CM), based on the systematic application of pesticides and lacking vegetal cover, to the Integrated pest Management (IPM), in which the application of pesticides is limited, being applied according to more rational criteria. In addition, an herbaceous vegetation cover is maintained in the olive grove, in order to limit soil erosion. Although they are of a minority nature, a lower proportion of olive groves are subject to Ecological Management (EM), in which pesticides are eliminated completely and the herbaceous vegetation cover is maintained, being only subject to scarce tillage operations. Here, the control of pests is exercised exclusively by beneficial fauna. The main objective of this study is to determine the impact of each of these agricultural management methods on beneficial entomofauna associated with the olive tree and characterize them according to the presence and abundance of a series of preselected species, characteristics of this agroecosystem. The study has been carried out by means of entomological samples in olive groves of the province of Jaén (south of Spain) corresponding to the three managements indicated above, during the spring of 2017. The results have allowed to select a total of 18 bioindicator species (11 predators and 7 parasitoids), all of them present in the Ecological, where they also presented the highest population densities. The lowest diversity and abundance corresponded to the conventional management, while the Integrated Management presented intermediate values with respect to the Conventional and Ecological management. The role of agricultural practices differential between these managements, are discussed.