RESUMEN. El nopalOpuntia ficus-indica se cultiva con diversos propósitos en el mundo, mientras que en México, principal productor y consumidor mundial, particularmente se consume como verdura (nopalitos). La producción de nopalitos se ubica, principalmente, en los alrededores de la Ciudad de México donde las cochinillas silvestres Dactylopius spp. son de los insectos más nocivos para el cultivo. El control químico es el método de más uso por los productores, aunque el control biológico podría ser útil para un manejo integrado de plagas. No obstante, los estudios taxonómicos sobre las especies de cochinilla y sus enemigos naturales en México no son abundantes. En esta investigación se planteó conocer las especies presentes de Dactylopius y sus enemigos naturales en Tlalnepantla, Morelos, una de las áreas de mayor producción de nopalitos en México. Se seleccionaron 30 sitios distribuidos en esta región y se establecieron cinco sitios para monitoreo de enemigos naturales cada dos semanas durante un año. La única especie de cochinilla silvestre del nopal que se encontró correspondió a Dactylopius opuntiae (Cockerell), los enemigos naturales en orden de abundancia fueron Leucopis bellula, Sympherobius barberi, Laetilia coccidivora, Hyperaspis trifurcata, Salpingogaster cochenillivorus, Sympherobius angustus y Chilocorus cacti. Se proporcionan descripciones de biología de los enemigos naturales en campo y laboratorio. Diversos factores relacionados con el manejo del cultivo tuvieron un efecto sobre las poblaciones de D. opuntiae y sus enemigos naturales.

El avance de la tecnología digital ha permitido concebir Sistemas de Vigilancia Epidemiológicos (SVE) automatizados con un enfoque <em>holístico-sistémico</em> favoreciendo la planeación, operación, gestión y procesamiento de datos fitosanitarios de manera efectiva y oportuna para toma de decisiones en la prevención y manejo regional de plagas. Este tipo de sistemas se enfocan en la salud del cultivo superando la visión reduccionista de plaga en la vigilancia normativa convencional. Un SVE web implica la definición clara del marco regional, objetivos, plaga(s) en su amplia acepción, recursos humanos/financieros, contexto normativo, líneas de investigación de soporte, estructura operativa y modelos de innovación. Estos elementos determinan la precisión, frecuencia y tipo de muestreo y monitoreo, así como las variables de medición relativas a un novel<em> sistema epidemiológico</em>. A diferencia de la vigilancia normativa, un SVE web <em>holístico-sistémico</em> tiene capacidad descriptiva y de pronóstico de riesgos, incluyendo alertas tempranas a partir de análisis espaciales y temporales. La interfaz web SVE asegura la generación flexible y dinámica de reportes y/o análisis automatizados. Un SVE operado en plataformas web, con énfasis en lenguajes de programación y herramientas de uso libre puede ser alojado en servidores genéricos o dedicados para almacenamiento de metadatos configurados con tecnologías Linux/Apache y funcionalidad 24/7 (h día-1). Programas de uso libre incluyen MySQL/MariaDB y otros como gestores de bases de datos; PHP / Node.js, y JavaScript, Ajax, HTML5 y CSS, como tecnologías web de maquetado base ‘back-end’ y ‘front-end’, respectivamente. Esta revisión se enfoca en principios, atributos conceptuales, enfoques metodológicos generales y objetivos de SVE base web. Aplicaciones generales se ilustran con un SVE desarrollado en México para el cafeto (<em>Coffea</em> spp.), el cual permitió operar la vigilancia de 19 plagas, nueve con estatus cuarentenario, mediante la generación, gestión y análisis de 87.4 y 15.7 millones de registros climáticos y epidemiológicos, respectivamente, obtenidos entre 2013-2019.

The temporal progress of malformation (MM) of mango (Mangifera indica) was studied from 1993 to 1995 with three management technologies applied to commercial plantations in North Guerrero, Mexico. Management influenced shoot production and thus determined the dynamics of epidemics. Environmental factors also affected disease incidence, particularly through an apparent effect on inoculum dispersal. In general, integrated management (IM), consisting of pruning, acaricide, and fungicide sprays, resulted in slower rates of epidemic development, lower levels of initial and final disease, and lesser areas under the disease progress curves. In the first cycle, IM increased yield per tree by 51% in relation to high technology (HT) and 74% in relation to lower traditional technology (LT), representing a benefit-cost rate of 2.8 and 3.3, respectively. Change of malformation incidence was correlated positively with the number of macroconidia of Fusarium sp. trapped in the canopy (r = 0.90, P = 0.0001) and wind speed (r = 0.83, P = 0.0001); both variables lagged over a 4-month period. The greatest change in malformation occurred during the main vegetative flush, which occurred 3 to 6 months after picking the fruit (May). The accumulated proportion of diseased shoots was correlated with the following variables measured over a 1-week period: average maximum daily temperature (r = -0.68, P = 0. 01), average temperature per hour (r = -0.59, P = 0.04), average number of hours with relative humidity ≥60% (r = -0.82, P = 0.001), and wind speed (r = 0.94, P = 0.0001). In general, the greatest spore density was found during the rainy season, with a morning periodicity showing the highest correlation with wind speed (r = 0.812, P = 0.0001). F. subglutinans was isolated consistently from diseased (86%) and asymptomatic (5%) vegetative and flowering shoots.

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Brevipalpus phoenicis s.l. is an economically important vector of the Citrus leprosis virus-C (CiLV-C), one of the most severe diseases attacking citrus orchards worldwide. Effective control strategies for this mite should be designed based on basic information including its population structure, and particularly the factors that influence its dynamics. We sampled sweet orange orchards extensively in eight locations in Brazil and 12 in Mexico. Population genetic structure and genetic variation between both countries, among locations and among sampling sites within locations were evaluated by analysing nucleotide sequence data from fragments of the mitochondrial cytochrome oxidase subunit I (COI). In both countries, B. yothersi was the most common species and was found in almost all locations. Individuals from B. papayensis were found in two locations in Brazil. Brevipalpus yothersi populations collected in Brazil were more genetically diverse (14 haplotypes) than Mexican populations (four haplotypes). Although geographical origin had a low but significant effect (ca. 25%) on the population structure, the greatest effect was from the within location comparison (37.02 %). Potential factors driving our results were discussed.

Huanglongbing (HLB), a recent worldwide spreading disease on citrus, was detected in July 2009 in Yucatan State of Mexico. The objective of this study was to evaluate the fit of diffusion and classic disease gradient models to large-scale HLB spatial data originated from initial foci to improve sampling, monitoring, and control strategies for Diaphorina citri, vector of Candidatus Liberibacter asiaticus (CLas), putative agent of HLB. Four transect routes were selected: Yuc-1, Yuc-2, QRoo-1, and QRoo-2, based on the directionality of the prevailing winds and foci location of HLB infected plants. In these routes, 35 sites, 5 to 20 km apart, were selected for monthly evaluation during a 12-month period. A 10-insect sample and disease incidence and severity of HLB, further confirmed by PCR, were assessed per site. Mexican lime was more vulnerable (67.5%) than sweet orange (14%). Also, leaf symptoms were mostly found with homogeneous distribution but rarely reaching 100% of the tree canopy during the 12-month period. The diffusion model provided the best fit among the family of time-gradient curves (r2 = 0.90 to 0.99) due to the flexibility of a three-parameter model. The gradients were well conformed to the model in a 25 to 82.6 km range, having the east-west direction the longest effect. Yuc-2 and QRoo-2 transects showed 82.6 and 43.9 km gradients with a diffusion coefficient (Do) of 0.15 and 0.09, respectively. This study constitutes the first quantitative evidence of the regional spread of CLas from a single focus and the application of a flexible model that improved the fit and allowed to better compare different gradients. These results are useful to determine the size of Regional Areas of Diaphorina citri Control (ARCO), a management program currently implemented in Mexico to combat HLB.

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<p>The objective of this work was to determine the impact of COVID-19 on productive activities of farmers and extensionist, and the level of application of Integrated Pest Management (IPM) in urban agriculture in Xochimilco, Milpa Alta, Tláhuac, Tlalpan, Magdalena Contreras and Cuajimalpa at Mexico City, a metropolitan area with a high SARS-CoV-2 positive cases. In 2020, a digital survey was applied to a total of 108 farmers and extensionists during the first COVID-19 epidemic wave. The sanitary emergency reduced the continuity of the extension service. However, this was carried out with digital technologies including photographs submitted by WhatsApp for pest diagnosis purposes. During the maximum COVID-19 peak (July, 2020), only 14% of farmers declined to sowing the summer fall season 2020. The majority established corn and, to a lesser extent, vegetables in mixed topologies. However, the activity of agricultural workers was reduced to 50%. Up to 75% of farmers reported losses of 20% derived from the epidemic. The major pest control strategy was mechanical, mainly for preventive purposes (67%) followed by chemical control (52%), biological at both preventive (8%) and curative (25%) levels, and the combination of more than one strategy in less than 10%. The data indicate an intuitive understanding of the IPM benefit, although the farmer is unaware of its principles. Faced with the growing demand for fresh, quality and safe food as a COVID-19 preventive strategy, urban agriculture has great development prospects by supplying local markets without transport problems caused by regional and global contingencies such as that caused by SARS[1]CoV-2. However, public and institutional policies of great vision are required. This work recognizes the work of farmers, as well as extensionists in favor of food security.</p>