A Comparison of IPM and Organic Farming Systems Based on the Efficiency of Oophagous Predation on the Olive Moth (Prays oleae Bernard) in Olive Groves of Southern Iberia

Abstract

The olive moth, Prays oleae (Bernard, 1788) (Lep., Praydidae), is one of the most common insect pests affecting the olives groves of the Mediterranean basin. Current farming practices are largely oriented to optimize the effectiveness of beneficial insects, among which the common green lacewings (Neur., Chrysopidae) stand out. Two different types of management models, organic and IPM, were compared in this study, which was conducted in olive groves in the regions of Andalucía (Spain) and Alentejo (Portugal). During 2020 and 2021, fruit samples were periodically collected, analyzing the population parameters (POP) and potential attack on the fruit (%PA), as well as the predatory impact (%PRED), which has allowed the estimation of the final attack (%FA), and derived fruit recovery rates (%REC). The results show that in organic olive groves of both countries, the infestation parameters (POP, %PA) were significantly higher than in IPM ones. However, predation rates were also higher in organic olive groves, which resulted in REC rates of between 75% and 80%, reducing FA rates to values of approximately 10% and 20% in Portugal and Spain, respectively. In contrast, in the IPM olive groves, significantly lower predation values were recorded, with lower REC rates than in the organic olive groves; the rates were very similar in both countries (ca. 54%), which led to a higher percentage of fruit loss (%FA) equivalent to 22% (Portugal) and to 34% (Spain). This paper discusses potential drivers influencing differences in the population values and percentages of infestation by P. oleae observed, as well as the differences in the final attack rates between olive groves of both countries, subject to the same type of agricultural management.