Insect pests show phenotypic plasticity as a function of resource availability and limiting conditions. Although Rhynchophorus palmarum displays high variation in certain morphological traits, it is still not clear how and which of these are being filtered along agricultural management gradients in palm plantations. This study assesses the influence of biophysical structure of ornamental palm plantations and agrochemical use on morphological traits of adults in 15 permanent plots of ornamental palm plantations in Veracruz, Mexico. A total of 4972 adults were and their body length, pronotum width, rostrum length, and mesothorax depth were measured. Body length and mesothorax depth of adults of both sexes were greater in plantations with a high diversity of palm species and frequency of fertilizer use. Rostrum length of females increased as a function of palm density, and pronotum width of both sexes was positively related with the use of insecticides. Local characteristics of agricultural management of palm plantations might filter integrated, adaptative, and environment-specific phenotypes. This is the first ecological study of the south American palm weevil that provides new insights on the current intensive management of ornamental palm plantations that far from controlling, benefits current geographic expansion, demographic outbreak, and economic impact of this pest.

Thiamethoxam is a neonicotinoid with systemic and contact action, used in Mexico for the care of different traditional fruit crops, mainly in the cultivation of papaya. Soils of agroecosystems with papaya in the Gulf of Mexico area, the main producers of this fruit, are currently characterized as 45% of the producers organize papaya cultivation in rotation with watermelon at different sowing dates. The objective of this study was to determine the presence and concentration of thiamethoxam in soil and water during the rotation of papaya crop with watermelon culture in the central zone of Veracruz, Mexico. An analysis was carried out to know the management of thiamethoxam in different types of soil and in the region; and in an experimental plot. Soil and water samples were taken at different stages during the rotation of both crops. Those samples were taken systemically, starting with the watermelon culture cycle and then, during the phenological stages in the papaya crop cycle. Soil and water samples were analyzed using HPLC-UV equipment for its determination. The design was random blocks with six repetitions and the software used for data analysis was the Statistica 2007 program. Thiamethoxam was concentrated in amounts of ≥0.40 mg/L in 79% of the samples in water and ≥0.55 mg/kg in 75% of the samples in soil. The highest values of thiamethoxam in soil were in the stage of watermelon culture with 0.4 mg/kg and in the soil preparation of the papaya crop with concentrations of 0.8 mg/kg. Whereas irrigation water from the watermelon cultivation and the soil preparation for the papaya showed concentrations of 0.5 and 0.7 mg/L, respectively. The presence of thiamethoxam was identified in 100% of the samples analyzed in the stage of preparation of soil and water of the cultivation area, concluding a possible risk of residuality of thiamethoxam in fruits that exceed the maximum limits of tolerance established by the EPA, EFSA and FAO.

El chile Manzano o Cera (Capsicum pubescens), es una planta perenne originaria de las tierras altas de América del Sur. Durante su almacenamiento, el principal problema que presenta es su testa, lo cual ocasiona una disminución de la germinación en condiciones naturales. Debido a que existe poca información sobre la germinación, es necesario implementar alternativas que garanticen el recurso dentro de un programa de mejoramiento genético. El objetivo fue evaluar el efecto de ácido sulfúrico (H2SO4), peróxido de hidrógeno (H2O2) y ácido giberélico-3 (C19H22O6) sobre el porcentaje de emergencia y características de plántulas de semillas de C. pubescens. El experimento se realizó en la Unidad de Manejo y Conservación de Recursos Genéticos de la Facultad de Ciencias Biológicas y Agropecuarias de la Universidad Veracruzana. Se utilizaron semillas de C. pubescens provenientes de la localidad de Huatusco, Veracruz, México, almacenadas a temperatura ambiente durante un año. Los tratamientos estudiados fueron: inmersión en H2SO4 (100, 75, 60 %; 30 min); inmersión en H2O2 (20, 10, 15 %; 15 min), inmersión en C19H22O6 (25, 20, 15 mg; 24 h) y el tratamiento testigo. Los resultados en el presente estudio revelan diferencias estadísticas significativas (P ≤ 0,01) para todas las variables evaluadas. El mejor porcentaje de germinación se provocó con inmersión en C19H22O6 (15 mg; 24 h) y H2O2 (20 %; 15 min). El tratamiento con H2SO4 fue perjudicial ya que no hubo emergencia.