Induction of sublethal effects for the characterization of Olive groves under different pest management systems

Abstract

Currently, olive grove management in Spain responds to the three following clearly differentiated systems in order of decreasing area: Conventional Management (70%), Integrated Pest Management (IPM) (26%) and Ecological Management (4%) systems. These are characterized by a decreasing dependence on synthetic insecticides and by different soil tillage intensities. They are also subject to different subside regulations and application regimen by the government, so their adequate characterization represents a factor of increasing importance, which is the object of this work.During the years 2017 and 2018, olive groves corresponding to the three types of management were selected, in which two series of plots were established. In one series, Dimethoate 40® was applied, considering plots of the second series as control. After insecticide application, beneficial insects were monitored through the use of chromatic traps.The results allow elucidating two clearly different behavioral patterns in beneficial insects, depending on the use of insecticides: Conventional and IPM management, where repellency reaction is manifested, absent in the Ecological Management. Aspects about the induction of sublethal effects for the characterization of the different pest management systems are discussed.

Monitoring and Inference of Behavioral Resistance in Beneficial Insects to Insecticides in Two Pest Control Systems: IPM and Organic

“…Compared to traditional agriculture, the higher quality of products of organic origin leads to greater respect for the environment, as well as the progressive elimination of synthetic chemical products. Regarding pest control, biodiversity stimulation in organic crops will have an impact on the improvement of the entomophagous activity of natural enemies, which has been verified in the case of Prays oleae (Bernard, 1788) (Lepidoptera: Praydidae) [33].…”

“…To do this, the passive sampling technique was carried out using adherent yellow chromotropic traps (20 × 40 cm). This sampling methodology has provided excellent results and stands out for being easily replicable [33,62,[69][70][71]. Traps were immediately placed after experimental insecticide applications, at the rate of one per olive tree (16 traps per plot) and at a height of 1.5 m in the N sector of each tree.…”

“…Among the captured species, 12 species of natural enemies were selected (Table 2), which are relatively common in the entomofauna associated with olive grove pests in southern Spain [33,72,77,78]. Individuals of these 12 species of natural enemies were captured in both olive groves.…”

“…Individuals of these 12 species of natural enemies were captured in both olive groves. Due to its greater abundance, the A. intermedius predator stands out, which is a cosmopolitan species common in a wide range of crops [33,79,80]. Most of the captured species (nine species) are natural enemies of the olive moth P. oleae, which, as indicated, during sampling, is in the oviposition period corresponding to the anthophagous generation.…”

“…However, alternative and/or complementary procedures are required. In this sense, the absence of behavioral resistance in the beneficial insects in relation to synthetic insecticides is a distinctive characteristic of organic pest management with respect to conventional management and IPM [33]. This has been the determining element for the development of a reliable strategy for its characterization from a behavioral point of view.…”