Avocado is one of the most important crops in the world, and Mexico is the largest producer of this fruit. Several insect pests affect its production, and thrips are amongst the most important. A key step in the design of control methods is accurate species identification. Despite this, formal reports on species diversity of thrips in Mexico are very scarce. Morphological identification can sometimes be time-consuming and inconclusive. Therefore, we explored the species diversity of thrips in Mexican avocado orchards (Michoacan state) based on partial sequences of the mitochondrial gene cytochrome oxidase subunit I (COI). Forty-four specimens were analysed, which represented approximately 8% of all individuals collected from five localities distributed in three Municipalities. All specimens were analysed using the COI marker, and specimens within the genera Frankliniella were also analysed using a marker within the D2 domain of the 28S (28SD2) nuclear ribosomal DNA. Molecular identifications were confirmed using morphological taxonomy. Overall, six genera were found (Neohydatothrips, Scirtothrips, Frankliniella, Arorathrips, Caliothrips and Leptothrips). All genera contained only one species, except Frankliniella, for which there were six species. Data from the two molecular markers suggest the existence of cryptic species within Mexican F. occidentalis populations.

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The round-headed pine beetle Dendroctonus adjunctus, whose dispersion and colonization behaviors are linked to a communication system mediated by semiochemicals, is one of the five most critical primary pests in forest ecosystems in Mexico. This study provides the first head transcriptome analysis of D. adjunctus and the identification of the nonreceptor olfactory genes involved in the perception of odors. De novo assembly yielded 44,420 unigenes, and GO annotations were similar to those of antennal transcriptomes of other beetle species, which reflect metabolic processes related to smell and signal transduction. A total of 36 new transcripts of nonreceptor olfactory genes were identified, of which 27 encode OBPs, 7 encode CSPs, and 2 encode SNMP candidates, which were subsequently compared to homologous proteins from other bark beetles and Coleoptera species by searching for sequence motifs and performing phylogenetic analyses. Our study provides information on genes encoding nonreceptor proteins in D. adjunctus and broadens the knowledge of olfactory genes in Coleoptera and bark beetle species, and will help to understand colonization and aggregation behaviors for the development of tools that complement management strategies.

Background: Herbicide application to control weeds can promote a rapid selection of resistant phenotypes in small geographic areas. Also, in areas with a spatial heterogeneous management, resistance may evolve independently, promoting local adaptation in weeds. In the mexican region known as "El Bajio," 100,000 ha are cultivated with wheat, and the weed Phalaris minor, resistant to ACCase-inhibiting herbicides is commonly present. Question:We aim to identify the population structure of two genes in four different P. minor biotypes from "El Bajio" and to determine their association with phenology and plant growth differences (biomass and seed yield) that may contribute to survival in the agricultural environment.Studied species: Phalaris minor Retz. Study site and years of study: The study was carried out at a greenhouse and at the molecular biology laboratory of the Colegio de Postgraduados, during 2013 and 2014. Methods:The diversity of the psbA gene and the sequence of two ACCase gene fragments as well as phenology, growth and biomass allocation were evaluated. Results:Results indicated different polymorphism levels for the two genes. There were no differences in the psbA gene between biotypes, although the ACCase gene exhibited high polymorphism level. In addition, each biotype showed differences in phenology, biomass accumulation and fecundity. Conclusions:The ACCase-inhibiting herbicide resistance in "El Bajio" region might be a resistance hotspot leading to the local adaptation of weeds.Key words: Evolution, herbicide resistance, local adaptation. ResumenAntecedentes: La aplicación de herbicidas para el control de las malezas puede fomentar una rápida selección de fenotipos resistentes en áreas geográficas pequeñas. También, en áreas con un manejo heterogeneo espacial, la resistencia puede evolucionar independientemente, promoviendo adaptaciones locales de las malezas. En la region mexicana conocida como "El Bajío", se cultivan 100,000 ha con trigo, y la maleza Phalaris minor, resistente a herbicidas inhibidores de la ACCasa está comunmente presente.Pregunta: El objetivo fue identificar la estructura poblacional de dos genes en cuatro biotipos diferentes de P. minor de "El Bajío" y determinar su asociación con las diferencias en fenología y crecimiento de la planta (biomasa y rendimiento de semilla) que puedan contribuir a la sobrevivencia en campos agrícolas.Especie estudiada: Phalaris minor Retz. Sitio y años de estudio: El estudio se realizó en un invernadero y en el laboratorio de Biología Molecular del Colegio de Postgraduados durante 2013 y 2014.Métodos: La diversidad del gen psbA y la secuencia de dos fragmentos del gen ACCasa fueron evaluados, así como también la fenología, el crecimiento y la asignación de biomasa.Resultados: Los resultados indicaron diferentes niveles de polimorfismo para los dos genes. No hubieron diferencias en el gen psbA entre los biotipos, aunque el gen ACCasa exhibió nivel alto de polimorfismo. Además, cada biotipo mostró diferencias en la fenología, acumulación de ...