The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is an introduced pest in Mexico and a vector of huanglongbing, a lethal c

Vector control in huanglongbing management has been conducted on a calendar basis resulting in high production costs. We addressed this issue and proposed a sequential sampling plan to support decision making for intervention against Diaphorina citri Kuwayama, which is involved in the transmission of the bacteria Candidatus Liberibacter asiaticus, associated with such lethal disease. We analyzed 3,264,660 records from samples gathered from the Mexican trapping program for the monitoring of D. citri; it included weekly inspection of 86,004 yellow sticky traps distributed in the country. Spatial distribution of the insect, estimation of a common k (kc), and sequential sampling plans based on Sequential Probability Ratio Test (SPRT) were determined. Taylor’s power law coefficients were ≥1 indicating aggregation in the spatial distribution of the insect. Common k ranged from 0.0183 to 0.2253 and varied independently of geographic zone or citrus species. We obtained 18 sequential sampling plans, one for each state. In the Average Sample Number (ASN) function, the minimal number of samples to make a decision ranged from 17 to 65. In the Operational Characteristic (OC) function, probabilities for a correct intervention at the threshold of 0.2 D. citri adults/trap in most cases were above 80%. In a field evaluation, the application of sampling plans yielded savings obtained by reduction in the number of interventions for insect control.

We analyzed the morphological and genetic variation of the Asian citrus psyllid nymphal ectoparasitoid Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) in 2 regions of Mexico, in the northeast (represented by the states of Nuevo León and Tamaulipas) and the west (represented by the states of Colima and Michoacán). We found that the morphological variation of the specimens lay mainly in body color traits. The morphometric study indicated that in comparison with females, males presented heterogeneity, and it was concentrated in the state of Colima. Despite the morphological variation found in the species, it was not exclusively associated with any of the geographical regions. Molecular analysis revealed the presence of 2 haplotypes (H1 and H2), which were the same found in previous research among strains introduced to Florida. Haplotype H2 was found in both studied regions and more frequently than haplotype H1, which was collected only in the northeast (Tamaulipas state), suggesting possible... Resumen En el presente estudio se analizó la variación morfológica y genética del ectoparasitoide ninfal del psílido asiático de los cítricos Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) en dos regiones de México, región noreste (representada por los estados de Nuevo León, y Tamaulipas) y región occidente (representada por los estados de Colima y Michoacán). Se encontró que la variación morfológica de los especímenes analizados recae principalmente en variables cromáticas. En el estudio morfométrico se encontró que a diferencia de las hembras, los machos presentan heterogeneidad, la cual se concentró en el estado de Colima. La variación morfológica en el parasitoide no se asoció de forma exclusiva por alguna de las zonas geográficas de estudio. El análisis molecular reveló la presencia de dos haplotipos (H1 y H2), los cuales se han encontrado en investigaciones previas entre las poblaciones del parasitoide introducidas a Florida, E.U.A. El haplotipo H2 se encontró en todas las áreas de estudio ...

Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) es un ectoparasitoide específico de Diaphorina citri Kuwayama (Hemiptera: Liviidae) vector de Candidatus Liberibacter spp., el agente causal del Huanglongbing, una enfermedad devastadora de los cítricos a nivel mundial. El parasitoide se introdujo accidentalmente a diversas regiones del continente Americano, entre ellas México, en donde actualmente es reproducido masivamente y liberado. Como contribución al conocimiento del uso de las poblaciones silvestres del parasitoide en beneficio de la citricultura mexicana, el objetivo del presente estudio fue caracterizar genéticamente poblaciones de T. radiata en el estado de Tamaulipas, México; mediante secuenciación de ADN mitocondrial (gen de la citocromo oxidasa subunidad 1) analizando muestras del parasitoide colectadas durante los años 2006-2013. De los especímenes obtenidos se encontraron dos haplotipos (H1 y H2) de los cuales el H1 se ha encontrado en la mayor parte de las zonas citrícolas infestadas por D. citri en México, mientras que el H2 sólo ha sido detectado hasta el momento en los estados de Tamaulipas y Yucatán. La distribución limitada del H2 sugiere las posibles entradas del parasitoide a México, lo cual es apoyado por el agrupamiento del H2 en el análisis estadístico de parsimonia con haplotipos que hasta el momento sólo se han encontrado en Florida.

Orange jasmine (OJ) is a common ornamental plant used as green hedge in public and private gardens in Mexico. It also hosts Huanglongbing, a worldwide citrus disease and its vector, Diaphorina citri. For risk analysis and management purpose is important to know its geographic distribution. The potential distribution of OJ was calculated in Mexico using a deductive approach. Based on temperature and precipitation requirements, a relative suitability index was computed by combining the normalized values of both variables. The distribution was overlapped with captures of D. citri to check their spatial similarity. The results showed that the potential of occurrence is high in the Pacific and Gulf of México coastal states, including the Yucatán peninsula, and the lowest values appeared in the north-western states. The OJ distribution overlaps with Huanglongbing occurrence and coincided with captures of D. citri for most of the suitable area but D. citri captures extended beyond the optimal OJ distribution values in the northern regions of Mexico.