Summary Soybean rust (Phakopsora pachyrhizi Sydow & Sydow), is a limiting factor for soybean [Glycine max (L.) Merril] production because it causes yield losses of up to 80 %. In Mexico there are few studies on the influence of fungicides on the epidemic development of the disease, its relationship with climate and the impact on yield. The objective of this study was to evaluate the effect of: a) pyraclostrobin + flutriafol, b) pyraclostrobin + epoxiconazole, and c) epoxiconazole on the soybean rust epidemic development as well as the impact of the disease on grain yield and the effect of climatic variables on the disease. Seven experiments were carried out over a three-year period in Altamira, Tamaulipas, Mexico. Significant differences (P ≤ 0.05) were only detected in the incidence and the area under the disease progression curve (AUDPC) with the application of pyraclostrobin + epoxiconazole, which decreased the incidence levels by 88 to 96 % and severity by 95 to 98 %; in addition, it prevented losses of grain yield by 11.2 to 25.6 %. The application of pyraclostrobin + flutriafol and epoxiconazole did not cause differences on severity and AUDPC of soybean rust compared to the control without fungicide application. Weather variables associated with a higher probability of rust occurrence were the number of hours with temperatures between 17.5 and 32.5 º C, in combination with the number of hours with leaf moisture between 10 and 15 (scale 0 to 15) and with relative humidity higher than 70 %.

Resumen La roya asiática (Phakopsora pachyrhizi Sydow & Sydow) es una limitante para la producción de soya [Glycine max (L.) Merril] debido a que causa pérdidas de rendimiento de hasta 80 %. En México, son escasos los estudios sobre la influencia de fungicidas en el desarrollo epidémico de la enfermedad, su relación con el clima y el impacto en el rendimiento. El objetivo de este estudio fue evaluar el efecto de la aplicación de: a) pyraclostrobin + flutriafol, b) pyraclostrobin + epoxiconazole, y c) epoxiconazole, sobre el desarrollo epidémico de la roya asiática de la soya, así como el impacto de la enfermedad sobre el rendimiento de grano y el efecto de variables climáticas sobre la enfermedad. Se establecieron siete experimentos en un periodo de tres años en Altamira, Tamaulipas, México. Únicamente se detectaron diferencias significativas (P ≤ 0.05) en la incidencia y en el área bajo la curva del progreso de la enfermedad (ABCPE) con la aplicación de pyraclostrobin + epoxiconazole, la cual disminuyó los niveles de incidencia de 88 a 96 % y la severidad de 95 a 98 %; además, evitó pérdidas de rendimiento de grano del orden del 11.2 al 25.6 %. La aplicación de pyraclostrobin + flutriafol y de epoxiconazole no causaron diferencias sobre la severidad y el ABCPE de la roya asiática, en comparación con el testigo sin aplicación de fungicidas. Las variables climáticas asociadas con una mayor probabilidad de ocurrencia de la enfermedad fueron el número de horas con temperaturas entre 17.5 y 32.5 º C, en combinación con el número de horas con humedad foliar en el intervalo de 10 a 15 (escala 0 a 15) y con humedad relativa mayor de 70 %.

In two field-collected populations of de Bemisia tabaci (Gennadius) B biotype previously selected with the neonicotinoid insecticide thiamethoxam (NEO-R, NEO-N), and a population susceptible to insecticides (SUSC), the level of response to the insecticide thiametoxam, as well as the life and fertility tables were determined. At LC95, the NEO-R population showed a resistance ratio (RR95) value of 8.8-fold, an intrinsic rate of increase (r m) of 0.72. The fitness of the NEO-R and NEO-N populations in relation to the SUSC was 1.5 and 2.0, respectively. The RR95 value for NEO-N was 1.9-fold; it's r m value was 0.082, while in the SUSC population was 0.041. The developmental time of egg and adult were longer in NEO-R population, while the nymph and pupa lasted longer in the NEO-N and SUSC populations. The developmental time was different in the three NEO-R, NEO-N, and SUSC populations with 19.7 d (315.84 degree days or dd), 15.7 d (250.4 dd) and 18.5 d (296.6 d), respectively. The populations previously selected with thiamethoxam did not reproduce faster than their susceptible counterpart.

Ten species of Agromyzidae of agronomic interest in Texcoco, (state of Mexico); Altamira, (state of Tamaulipas), Magdalena Contreras, (Mexico City), and Nativitas, (state of Tlaxcala) are presented. A description of the adults, their geographic distributions and their host plants, are provided. In addition a key with photographs of the aedeagus and sperm pumps of all species are provided. The species included are: Amauromyza abnormalis (Malloch), Liriomyza brassicae (Riley), Liriomyza sabaziae Spencer, Liriomyza trifolii (Burgess), Melanagromyza minimoides Spencer, Melanagromyza neotropica Spencer, Melanagromyza splendida Frick, Melanagromyza tomaterae Steyskal, Melanagromyza viridis (Frost) and Ophiomyia lantanae (Froggatt).

Se presentan diez especies de Agromyzidae de interés agronómico en Texcoco, (Estado de México), Altamira, (Tamaulipas), Magdalena Contreras, (D. F) y Nativitas, (Tlaxcala). Se proporciona una descripción del adulto, distribución y plantas hospederas de cada especie, además de una clave para su identificación con fotografías que ilustran las características del edeago y bomba eyaculadora por especie. Las especies identificadas fueron: Amauromyza abnormalis (Malloch), Liriomyza brassicae (Riley), Liriomyza sabaziae Spencer, Liriomyza trifolii (Burgess), Melanagromyza minimoides Spencer, Melanagromyza neotropica Spencer, Melanagromyza splendida Frick, Melanagromyza tomaterae Steyskal, Melanagromyza viridis (Frost) y Ophiomyia lantanae (Froggatt).