Search

The cultivation of citrus in the Mediterranean region is of considerable economic importance. The viability of this industry is contingent upon a number of factors, with adequate phytosanitary management being of particular significance. During the last decade, the geographical range of the invasive psyllid, Trioza erytreae (Del Guercio, 1918), has expanded to the mainland territories of Portugal and Spain. Trioza erytreae acts as a vector for the Huanglongbing disease (HLB). This review presents the current knowledge about the hosts of the psyllid and their attractiveness and suitability. A classification of the hosts according to their suitability, as assessed in the literature, is provided. The attributes of the hosts and the methods used to assess their suitability are described, as well as the climatic factors that affect the psyllid–host interaction. The review emphasises the importance of a comprehensive evaluation of the interactions between the psyllids and their hosts to develop and implement more effective strategies for controlling T. erytreae. [ABSTRACT FROM AUTHOR]

The Mediterranean basin is the leading worldwide region for olive production. Extreme weather is increasingly frequent in this region, and how these climate extremes will affect olive products and quality remains unknown. We aim to study the effects of the water deficit stress, which occurred in the summer of 2017, on olive fruit and oil quality from a 30-year-old orchard. Fruits from olive trees standing on (i) one hydrated and (ii) one dry area of an orchard at the north of Portugal were harvested. Fruits' water content, oil yield and quality, fruit carbohydrates, and fruit and oil phenolic metabolite profiles were analyzed. Fruits from the dry area presented low water availability and increased carbohydrates, oleuropein, oleoside, and elenolic acid glucoside abundance. Oil yield was lower in the dry area, but the abundance of oleacein increased, together with traits of some sensory sensations. Climate stress events can reduce oil yield but stimulate the accumulation of bioactive compounds that improve oil quality and nutritional value. [ABSTRACT FROM AUTHOR]

Individual based models (IBMs) are up-to-date tools both in research and educational areas. Here we introduce an IBM built on NetLogo platform that simulates a top-down trophic cascade controlled by the pressure exerted by two model predators (web-building spiders and ground runner spiders) on a model pest (the olive fruit fly) within a hypothetical agricultural landscape (the olive crop). EcoPred is an IBM that aims to be an educational tool that can help teachers to explain concepts related to ecology in a modern, enjoyable and comprehensive way. EcoPred reflects the changes on a fly population within a simulated olive crop according to (1) the mortality rate caused by the predation of two spider species and energy loss, (2) the energy gain by feeding on flowers and (3) the reproduction rate in olive trees. The model was tested with 26 students achieving very good results in terms of acceptance and interest on the learning method. EcoPred can be used for educational purposes with 16 year old students and older to explain ecological concepts such as trophic level, species interactions, limiting factor and biological control in an interactive way simultaneously introducing students to biology oriented programming languages.

The ground-cover vegetation, commonly found in olive groves, provides shelter and vital floral resources for syrphids. Such resources can contribute to syrphids' growth, development, reproduction, and survival, allowing them to maximize their function as natural pest enemies, pollinators, and decomposers of organic matter. Therefore, identifying the flowering plant families driving the abundance of Sphaerophoria scripta Linnaeus, 1758, is essential to promote its presence and abundance. Here, we described the flowering plants present in the vegetation cover of olive groves and studied how these flowering plant families shape the abundance of S. scripta. A total of 90 plant species belonging to 20 families were identified. Asteraceae was the dominant flowering family, followed by Poaceae. The generalized linear model showed that the presence of flowering plants of the families Campanulaceae, Asteraceae, Orobanchaceae, and Plantaginaceae in the ground-cover vegetation promotes the abundance of S. scripta in olive groves. Conversely, flowering plants of the families Poaceae and Polygonaceae were associated with the decreased abundance of this syrphid species. Our results suggest that increasing particular plant families and decreasing others in the ground-cover vegetation may favor S. scripta abundance in the Mediterranean olive groves. [ABSTRACT FROM AUTHOR]

Phyllocnistis citrella Stainton, commonly known as the citrus leafminer, threatens global citrus production. This study focuses on elucidating the population dynamics and spatial distribution of P. citrella in lemon orchards located in Northern Portugal. From May to December, using delta traps with sexual pheromones, the levels of the adult population were monitored, and aggregation indices were calculated. Five distinct density peaks are observed, with the highest recorded in late July to early August. Spatial distribution consistently indicated an aggregated pattern. However, temporal variation in distribution was observed on specific dates. According to our results, it is suggested deploying two or three traps per hectare during peak density periods. This study significantly advances our understanding of P. citrella dynamics, emphasizing the need to consider spatial and temporal patterns for effective pest management. The outcomes underscore the importance of further exploration into factors influencing distribution patterns to refine control strategies. These insights are crucial for devising targeted and efficient measures to mitigate the impact of P. citrella on citrus orchards globally. [ABSTRACT FROM AUTHOR]