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Huanglongbing (HLB) is the most devastating citrus disease in the world and has been present in the state of Colima since 2010, the area producing Mexican lemon (Citrus aurantifolia). This disease causes an imbalance in the distribution of carbohydrates and inhibits photosynthesis. It also affects the concentration of nutrients in leaf. The objective of this work was to determine the physiological changes in trees in Mexican lemon production infected with HLB. The study was carried out in Colima in 2017. The concentration of starch, sucrose and glucose was determined in the central leaf veins and sheet of leaves of different ages (120 and 30 days) and root starch. The concentration of chlorophylls by analytical method and SPAD index in leaves with different levels of HLB symptoms and foliar analysis of mineral nutrients. The leaves with HLB had a higher concentration of starch in the 120-day leaf. Sucrose was concentrated in the leaf veins of 120 days. While glucose was increased in the leaf veins of 30 and 120 days. The roots of trees infected with HLB showed 40% lower concentration of starch compared to healthy trees. Decrease in chlorophyll content and SPAD index depending on the degree of involvement. As well as lower concentration of K, Ca, Mg, Cu, Fe, Zn and B. Knowing the changes caused by HLB in Mexican lemon will allow to develop practices that reduce its impact. [ABSTRACT FROM AUTHOR]

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Malformation is one of the most important diseases of mango worldwide. Several Fusarium species have been identified as causal agents of this disease. Recently, a new species, F. mexicanum, was described causing malformation in mango orchards located in the central western region of Mexico; however, it was not detected in producing areas along the Gulf of Mexico. During the last years, there has been an increase in mango orchards presenting malformation in Jalisco, a state located north of the area where F. mexicanum has been detected. The objective of this work was to identify the pathogen causing floral and vegetative malformation in Jalisco. Morphological and genetic analyses of the genes ß tubulin, EF-1α, and histone H3, indicated that all the isolates studied were F. mexicanum. This pathogen is confirmed as the main species causing mango malformation in those states located along the central Pacific region. Phylogenetic analysis showed that F. mexicanum may be present as clonal populations whose dispersal could have occurred through commercialization of contaminated plants from nurseries. F. mangiferae, F. sterilihyphosum and F. subglutinans type, species causing malformation in other countries, were not detected in this study. [ABSTRACT FROM AUTHOR]

The Annonaceae family is one of the oldest angiosperms. The genus Annona is the one with the most species and, together with Asimina, the only ones that contain edible fruits. In the last 10 years, interest in these fruit species has increased, mainly due to their nutritional properties and their application in the treatment of human diseases. Mexico is the center of origin for most of them. However, at present much of the basic agronomic information, postharvest handling of the fruits, and their potential as new crops for areas with poor soils in organic matter or semi-dry climates is unknown. It is considered that these custard apple species may be an option to change towards instead of crops that have lost profitability and sustainability. A review of the current state of knowledge in different areas of the species A. muricata, A. macroprophyllata, A. reticulata, A. squamosa, and A. cherimola was carried out and to focus research efforts on the topics of greatest interest and on those where is required to achieve a sustainable production and use of these resources in Mexico. However, knowledge about the cultivation and potential uses of these species is needed to increase their commercialization; the integration of interdisciplinary and interinstitutional groups is required. [ABSTRACT FROM AUTHOR]

Candidatus Liberibacter asiaticus ( CLas) es una bacteria fastidiosa transmitida por el psílido asiático de los cítricos Diaphorina citri Kuwayama que causa la enfermedad de Huanglongbing (HLB) en cítricos. La bacteria mantiene una asociación compleja con el psílido. Para entender mejor estas relaciones y determinar el efecto del patógeno sobre su vector, la supervivencia y reproducción de Diaphorina citri, fueron comparadas en plantas sanas de naranja y lima mexicana y plantas infectadas con CLas. Las tablas de vida indican que la supervivencia y longevidad de adultos de D. citri fue mayor en plantas de naranja (70-74%) respecto a las criadas en lima (58-61%). El tiempo de desarrollo del psílido de huevo a adulto se redujo sobre las plantas de naranja infectadas con CLas (15 d) en comparación con plantas de lima infectadas y plantas sanas (16-17 d). En ambos hospederos, la mayor mortalidad (dx) se presentó en huevo (14-30%) y superó la mortalidad acumulada del resto de los estados ninfales (13-18%). La fecundidad (mx) (633 huevos/hembra), la tasa neta de reproducción (R0) (221 descendientes/hembra/generación); la tasa intrínseca de incremento (rm) (0.13 hijas/hembra/d), la tasa infinita de crecimiento (λ) (1.14 individuos/d) y tiempo de generación (T) (41 d) fueron mayores hacia los psílidos criados en naranja infectada, en comparación con los criados en plantas sanas y lima infectada. Estos resultados sugieren un efecto benéfico de la bacteria para psílidos portadores criados en naranja y una interacción reciproca entre la bacteria y los psílidos criados en lima mexicana. En consecuencia las poblaciones del psílido serán más abundantes en plantaciones de naranja infectadas con el HLB, por lo que las medidas de control contra el vector deben diseñarse con base en la especie hospedera y si está infectada o libre de CLas. Candidatus Liberibacter asiaticus ( CLas) is a fastidious bacteria transmitted by the Psyllid Asian Citrus, Diaphorina citri Kuwayama (Hemiptera: Liviidae) which causes the disease Huanglongbing (HLB) in citrus. The bacterium has a complex association with its vector, the psyllid. To further understand these relationships, the survival and reproduction of Diaphorina citri were compared on CLas infected and healthy orange and Mexican lime plants to determine the effect of pathogen on its vector. Life tables were constructed starting with cohorts of recently laid eggs and the fecundity tables were obtained from 30 females per treatment. The survival and longevity of adults of D. citri were greater on orange plants (70-74%) with respect to Mexican lime plants (58-61%). Time development of psyllid, from egg to adulthood, was reduced on CLas infected orange plants (15.15 days) compared with infected Mexican lime and healthy plants (16-17 d). In both hosts, the highest mortality (dx) was presented in egg stage (14-30%); and it surpassed the cumulative mortality of nymphal stage (13-18%). Fecundity (mx) (633 eggs/female), the net rate of reproduction (R0) (221.73 descendants/female/ generation), the intrinsic rate of increase (rm) (0.13 daughters/female/day), the infinite rate of growth (λ) (1.14 individuals/day) and the generation time (T) (41days) were favorable toward the psyllids carriers on orange compared with infected Mexican lime and healthy plants. Results suggest a beneficial effect of CLas on the psyllids carriers reared on orange and a reciprocal interaction between bacteria and the psyllids reared on Mexican lime. Consequently the psyllid populations will be more abundant in the HLB-infected orange plantations, therefore vector control measures should be designed based on the host species and whether is infected with CLas or not. [ABSTRACT FROM AUTHOR]

La yaca, Artocarpus heterophyllus Lam., es un cultivo reciente en México de producción principalmente para exportación. El barrenador de ramas, Neoptychodes trilineatus L., es la principal plaga. Se determinaron la incidencia de larvas en ramas y severidad, distribución espacial, y fluctuación poblacional de los adultos en Nayarit, México. El adulto se alimenta de brotes tiernos y de la cáscara de frutos en desarrollo, mientras que la larva barrena las ramas. Con una incidencia media de dos larvas por kilogramo de madera seca se le encuentra durante todo el año, a excepción de diciembre. La mayor infestación ocurre en septiembre con 5.4 larvas por kilogramo de madera. El 84.7% de los árboles presentaron síntomas de daños por barrenador. Con una incidencia media de 0.92 adultos por árbol, se recolectaron en abril, mayo, julio, agosto, noviembre, enero, y febrero. En enero se detectó la mayor infestación con tres adultos por árbol. La mayor presencia ocurrió en la región de Tecuitata con 1.7 adultos por árbol, seguido de Jalcocotán con 1.1 adultos por árbol. Jackfruit, Artocarpus heterophyllus Lam., in Mexico is a recent crop for the export market. The branch borer, Neoptychodes trilineatus L., is the main pest of the crop. The objectives were to determine the incidence of larvae in branches and severity, spatial distribution, and population fluctuation of adults at Nayarit, Mexico in 2018-2019. Adults feed on tender shoots and skin of developing fruits, while larvae bore the branches. With an average incidence of two larvae per kilogram of wood, they were found throughout the year, except in December. The greatest infestation occurred in September with 5.4 larvae per kilogram of wood. Eighty-five percent of the trees showed symptoms of borer damage, with a mean incidence of 0.92 adult per tree. Adults were collected in April, May, July, August, November, January, and February. In January, the largest infestation was detected with three adults per tree. The greatest presence occurred in the Tecuitata region with 1.7 adults per tree, and 1.1 at Jalcocotán. [ABSTRACT FROM AUTHOR]

Se registra Homalodisca ichthyocephala (Signoret 1854) (Hemiptera: Cicadellidae) sobre lima mexicana [Citrus aurantifolia (Christm) Swingle] en Colima, México. Este cicadélido se alimenta de la sabia de estos árboles y los utiliza como refugio. Se desconoce su impacto como plaga en este cultivo y no se realizan tácticas específicas para su control. En este trabajo se resalta la importancia de generar información sobre esta esta plaga, pues pudiera ser un potencial vector de la Clorosis Variegada de los Cítricos. In this report Homalodisca ichthyocephala (Signoret 1854) (Hemiptera: Cicadellidae), is reported for the first time on Mexican lime [ Citrus aurantifolia (Christm) Swingle] in the state of Colima, Mexico. This cicadellid feeds on the sap of the tree, using it also as refuge. Its impact as a pest on the crop is unknown and no specific tactics are taken to control it. This work highlights the importance of generating information on the insect, because it could be a potential vector of Citrus Variegated Chlorosis. [ABSTRACT FROM AUTHOR]

El psílido asiático de los cítricos (PAC; Diaphorina citri) es la plaga más importante que afecta a la lima mexicanao ( Citrus aurantifolia) en el trópico seco de México y es el vector de la enfermedad del Huanglongbing. Su control se basa en el uso de insecticidas sintéticos. La búsqueda de alternativas sustentables y eficaces es una prioridad en el manejo del PAC. En este estudio, se evaluó el efecto de diferentes tipos de aceites y extractos de plantas en el control de ninfas del PAC en el estado de Colima, México. Las pruebas fueron conducidas en árboles de lima mexicana y plantas de vivero infestadas con la plaga. Se realizó una aplicación foliar de cada tratamiento sobre brotes vegetativos de 5 a 7 días de edad. Las evaluaciones del número de ninfas vivas se hicieron antes y después de la aplicación de los aceites y los extractos de plantas. En la primera prueba, el aceite parafínico (99% de residuos no sulfonados) a concentraciones de 1, 2, y 3%, redujeron la población del PAC entre un 77 a 98% en comparación con el testigo sin control. En las otras pruebas, los diferentes aceites (parafínicos, de cocina y de cítricos) mostraron una baja infestación del PAC con relación al testigo. También, los extractos de neem, ajo y cebolla mostraron una reducción significativa de ninfas después de la aplicación. El aceite de semilla de Jatropha curcas tuvo una buena efectividad en el control del insecto. No se observaron signos de fitotoxicidad en los árboles tratados con cualquiera de los aceites durante el invierno, pero si los hubo durante el verano, principalmente con los aceites de cocina. Estos resultados demuestran que los aceites y extractos vegetales pueden ser incluidos en un programa de control del PAC en lima mexicana para reducir el uso de insecticidas sintéticos (organofosforados), los cuales están teniendo problemas de resistencia de D. citri. [ABSTRACT FROM AUTHOR]

Fusarium mexicanum has been described as the causal agent of mango malformation in several producing areas in Mexico. Isolates of F. mexicanum obtained from mango trees with malformation disease in Jalisco were characterized according to vegetative compatibility groups (VCGs). Isolates were cultured on minimal medium - supplemented with potassium chlorate (KClO3), NO3-, and L-asparagine, to generate spontaneous nitrate nonutilizing (nit) mutants. Mutants are detected as mycelia sectors chlorate-resistant, which are not able to utilize nitrate as a nitrogen source due to mutations at loci associated with the nitrate-assimilation pathway. F. mexicanum isolates generated 239 chlorate-resistant sectors of mycelia, out of 62.3 % were nit mutants. Phenotypic characterization detected 36.91 % mutants nit1, 28.18 % mutants nit3, 19.46 % mutants NitM and 14.76 % mutants nnu. Compatibility pairing tests amongst the mutants detected two VCGs in isolates of F. mexicanum from Jalisco. Isolates in one VCG from Jalisco were compatible with isolates of a previously identified VCG of F. mexicanum from Michoacan. A total of three VCGs were detected in the central Pacific region of Mexico. [ABSTRACT FROM AUTHOR]

Tamarind (Tamarindus indica L.) is an economically important crop in the dry tropical region of Western Mexico. During more than one decade, damage caused by a borer insect in tree branches and trunk have been observed. Until recently, the taxonomy and generalities of this pest were unknown. In this brief review, current knowledge of the tamarind borer is presented. The insect is a large beetle, 18 to 33 mm, glossy, of fusiform black- or brown-colored body with yellow/black alternate sections in tarsus and antennal segments. The adult is characterized by extremely long antennae as long as or longer than the body of the beetle. Each elytra has two yellow spots. The larvae are cerambyciform, whitish in color, and its head is wider than the rest of the body. The insect was identified as Trachyderes (Dendrobias) mandibularis Dupont. In this region, the borer has been observed affecting only tamarind, in spite of other hosts such as Mexican lime, orange, and mango. The borer attacks young plants and adult trees. Its control consists of cultural practices (irrigation and fertilization) to reduce damage. For infested trees, pruning of damaged branches is recommended and then killing the larvae to break its life cycle. The application of insecticides (painted) to the trunk of the trees is a preventive measure to control the borer. [ABSTRACT FROM AUTHOR]