Olive Landscape Affects Bactrocera oleae Abundance, Movement and Infestation

Abstract

The economic importance of Bactrocera oleae (Rossi) and the problems associated with insecticides make necessary new management approaches, including deeper biological knowledge and its relationship with landscape structure. Landscape complexity reduces B. oleae abundance in late summer–autumn in areas of high dominance of olive groves, but the effect of landscape structure in spring and in areas less dominated by olive groves has not been studied. It is also unknown whether the insect disperses from olive groves, using other land uses as a refugee in summer. This work evaluates the effect of landscape structure on olive fruit fly abundance and movement in spring and autumn, and infestation in autumn, in central Spain, an area where the olive crop does not dominate the landscape. A cost–distance analysis is used to evaluate the movement of the fly, especially trying to know whether the insects move away from olive groves in summer. The results indicate that B. oleae abundance is consistently lower in complex landscapes with high scrubland area (CAS), patch richness (PR) and Simpson landscape diversity index (SIEI), and low olive grove area (CAO). The cost–distance analysis shows that the fly moves mainly in spring, and amongst olive groves, but there is no evidence that land uses other than olive groves serve as a summer refuge. Olive fly infestation decreased with decreasing CAO and increasing CAS and SIEI, accordingly with the effect of landscape on abundance. Thus, mixing olive groves with other land uses, which are not a source of flies, can help improve control of this important pest.

A complex landscape favours the abundance and species richness of syrphids (Diptera: Syrphidae) in olive groves

“…The attack of P. oleae on olives was also positively related with the area of olive groves (Pascual, Ortega, & Villa, 2022), and in other study areas the abundance of P. oleae increased for higher percentages of surrounding olive groves (Alves et al, 2021). High CAO was associated also with higher abundance of the olive fruit fly, Bactrocera oleae (Rossi, 1790), in this (Ortega et al, 2022) and other study areas (Ortega, Pascual, & Rescia, 2016;Paredes et al, 2022). In other agroecosystems a higher crop percentage was also related to lower abundance of natural enemies or biocontrol (Gagi c et al, 2011;Jankovi c et al, 2017;Rusch et al, 2016).…”

“…On the other hand, a negative relationship was observed with the abundance of the ground beetle O. barbarus , especially in autumn (Lantero et al, 2019) and also with the abundance of pirate bugs (Hemiptera: Anthocoridae) (Pascual, Ortega, & Villa, 2022). B. oleae abundance was also lower in complex landscapes with high CAS (Ortega et al, 2022). In other study areas, seminatural habitats surrounding olive groves affected also negatively the abundance of the olive moth, P. oleae (Costa et al, 2020).…”

“…In the olive agroecosystem, syrphid larvae are predators of the olive psyllids, Euphyllura olivina (Costa, 1839) and Euphyllura straminea Loginova, 1973 (Hemiptera), the green moth, Palpita vitrealis (Rossi, 1794) and the olive moth, Prays oleae (Bernard, 1788) (Lepidoptera) (Rojo, Gilbert, Marcos‐García, Nieto, & Mier, 2003), contributing to biological control of these insect pests. The study of the effect of landscape structure on different trophic guilds and processes in the olive agroecosystem has received attention in the last 20 years, showing in general a beneficial effect of complex landscapes (Alves, Mendes, Alves da Silva, Sousa, & Paredes, 2021; Boccaccio & Petacchi, 2009; Costa et al, 2020; Lantero et al, 2019; Martínez‐Nuñez et al, 2020; Ortega, Moreno, Fernández, & Pascual, 2022; Ortega, Sanchez‐Ramos, González‐Nuñez, & Pascual, 2018; Paredes et al, 2022; Pascual, 2022; Picchi, Bocci, Petacchi, & Ending, 2016; Scalercio, Brandmayr, Iannotta, Petacchi, & Boccaccio, 2012; Villa, Santos, Pascual, & Pereira, 2021). We hypothesize that landscape complexity favours syrphid community in the olive agroecosystem.…”

Methodological approach to spatial analysis of agricultural pest dispersal in olive landscapes

“…While some natural land uses such as woodlands impair the movement of these pests, others such as riverbanks or scrublands act as a corridor or barrier, depending on the phenological cycle of each pest. This could indicate a greater dispersive capacity of these pests during the spring months, which has already been observed in the case of P. oleae (Villa et al, 2020 ), and in B. oleae (Ortega et al, 2021 ). This seems obvious as in spring and early summer there are no olives in the trees.…”

Biochar-Derived Smoke Waters Affect Bactrocera oleae Behavior and Control the Olive Fruit Fly under Field Conditions

“…The damage to the fruit [3] decreases quantity and quality, interfering with the biochemical drupe composition [4][5][6]. OLF infestation depends on cultivar [7,8] and landscape [9], and is influenced by the size of the drupes, the ripening period, the hardness of the epicarp, the quality of chemicals inside the drupes, the harvesting method and by the presence of substances on the surface of fruits (e.g., kaolin, copper, honeydew or bird feces) [10][11][12].…”