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Delineation of management zones is one key feature of precision agriculture (PA), an agricultural management strategy which aims to maximize productivity and sustainability of crops by making optimum use of inputs. Common means of achieving this include the delineation of site-specific management zones (SSMZ), which are subregions of crop fields where yield-limiting factors manifest homogeneously. For pest management, however, PAs standard approach to crop field zoning (e.g. mapping zoning factors, mapping responses, filtering zoning factors, field partitioning, validation of SSMZ) is difficult to implement. In this case, high dynamism of pest populations makes mapping zoning factors and response variables complex and resource-consuming endeavors. Moreover, partitioning crop fields for pest management purposes requires consideration of temporally dynamic zoning factors instead of stable ones. In this paper we propose the addition of an ecological layer to classic PA zoning approaches, in order to overcome obstacles to delineating SSMZ for pest management purposes. In particular, we explore the potential of precision sampling tools (unmanned aerial vehicles, Arduino data loggers) and species distribution modeling (SDM) as facilitators of such an ecological dimension. After contrasting two PA zoning methods against one novel SDM-based approach (described here) to partition a commercial orchard (9 ha, Citrus latifolia Tanaka) in terms of six virtual pests, results show several advantages in our SDM-based method and the occasional necessity of multi approach methodologies to assure adequate zone delimitation under particular infestation scenarios.

Instituto de Investigaciones Agropecuarias y Forestales. Instituto de Investigaciones sobre los Recursos Naturales. Instituto de Investigaciones Químico Biológicas. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Químico Farmacobiología. Programa Institucional de Doctorado en Ciencias Biológicas Baculoviruses (BVs) are pathogens viruses of insects, which are used currently around the world as bioinsecticides for the control of different agricultural pest. The Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) have a high specificity, pathogenicity, and virulence. Due that, it is considered as a promising alternative for controlling its host Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), one of the most important pest of worldwide of vegetables. It is widely known that the genotypic composition and insecticidal properties of BVs can differ among isolates from the same host as well as from different geographical regions. Therefore, selection of most effective isolate for a determined pest is very important in the development of a bioinsecticide. The first objective of this work was to study the genetic diversity and biological activity of four isolates of SeMNPV (SeSIN6, SeSIN8, SeSLP6, and SeSLP8) collected in two agricultural regions of Mexico (Chapter II). These isolates were compared with two characterized SeMNPV from the United States (SeUS1 and SeUS2) and one from Spain (SeSP2). Analysis of the viral genome with restriction enzymes confirmed that all Mexican isolates were SeMNPV isolates. However, molecular differences between the Mexican and the reference isolates were observed using PCR combined with restriction fragment length polymorphism (RFLP). For example, the Mexican isolates SeSLP6 and SeSIN6 were considered genotypic variants of the SeMNPV, while SeSIN8 and SeSLP8 isolates had a very similar pattern of DNA compared to the SeUS1 isolate. Los baculovirus (BVs) son virus patógenos de insectos, que actualmente son utilizados a nivel mundial como bioinsecticidas para el control de diferentes plagas de importancia agrícola. El nucleopoliedrovirus múltiple de Spodoptera exigua (SeMNPV, por sus siglas en inglés) es un virus que posee una alta especificidad, patogenicidad y virulencia. Debido a ello, es considerado como una prometedora alternativa para el control de su hospedero, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), una de las plagas más importantes de hortalizas a nivel mundial. Es ampliamente conocido que la composición genotípica y propiedades insecticidas de los BVs pueden diferir entre aislados que proceden de un mismo hospedero, así como de distintas zonas geográficas. Por tanto, la selección de un aislado más efectivo para una determinada especie plaga es un importante elemento para desarrollar un bioinsecticida. El primer objetivo de este estudio fue estudiar la diversidad genética y la actividad biológica de cuatro aislados del SeMNPV (SeSIN6, SeSIN8, SeSLP6 y SeSLP8) colectados en dos zonas agrícolas de México (Capítulo II). Estos aislados se compararon con dos aislados previamente caracterizados de este mismo virus, procedentes de Estados Unidos (SeUS1 y SeUS2) y uno de España (SeSP2). El análisis del genoma viral mediante enzimas de restricción confirmó que todos los aislados mexicanos son aislados del SeMNPV. Sin embargo, con el uso de la técnica de reacción en cadena de la polimerasa (PCR, por sus siglas en ingles) en combinación con la técnica de polimorfismo de longitud de fragmento de restricción (RFLP, por sus siglas en ingles), se observaron diferencias moleculares entre éstos y los aislados de referencia. Por ejemplo, los aislados mexicanos SeSLP6 y SeSIN6 se consideraron como variantes genotípicas del SeMNPV, mientras que los aislados SeSIN8 y SeSLP8 tuvieron un patrón muy similar de ADN comparado con el virus SeUS1.