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The pigmentation of Fusarium verticillioides (Sacc.) as factor of virulence in maize seedlings. This research aimed to determine the relationship between the color of the pigment produced by isolates of F. verticilliodes and virulence in maize seedlings. Symptomatic and asymptomatic corn cobs were collected in Veracruz State, Mexico during the springsummer cycle of 2008. The experiment was analyzed using an experimental design in split plots with a double division, under greenhouse conditions during two crop cycles, fall-winter of 2008 and spring-summer of 2009, in the Postgraduate College Campus Montecillo, Mexico State. The pigmentation of the isolates obtained from symptomatic seeds with mycelium was more intense with a purple color, and the white mycelium isolates showed a more homogeneous color. Isolates from asymptomatic seeds had a tenuous violet coloration, and from white to cream coloration of mycelium. It was observed that isolates from symptomatic and asymptomatic seeds were pathogenic; the purple isolations from symptomatic seeds were more virulent than the white isolate, opposite to what happened with the isolation from asymptomatic seeds, in which the white mycelium was more virulent.

Plutella xylostella is the main pest of cruciferous crops worldwide. To reduce P. xylostella populations, better integration of natural control and chemical control (dominant tactic used) is needed. This work analyzed the compatibility of nine insecticides with the parasitoid Diadegma insulare, outlining them as complementary tools in an integrated pest management strategy. The acute toxicity of spinosad, imidacloprid, indoxacarb, flonicamid, naled, pyridalyl, emamectin benzoate, and spinetoram against the parasitoid was assessed. Residual activity (persistence) was also evaluated over time; the mortality of the parasitoid in contact with leaf tissue of plants treated with insecticides was analyzed. According to the International Organization of Biological Control, all nine insecticides were toxic to D. insulare; the lowest mortality was recorded with spirotetramat (64%) and pyridalyl (48%), while the rest of the insecticides caused 100% mortality at 72 h after application. In terms of persistence, by days 14, 16, 16, 17, 17, 21, and 22 after application, flonicamid, naled, spirotetramat, spinosad, piridalyl, imidacloprid, and indoxacarb caused mortality of less than 25%, respectively, so they were considered harmless (Category 1). Nonetheless, some insecticide toxicity and residual activity must be regarded within integrated pest management programs for conserving the role of D. insulare field populations.

The Annonaceae fruits weevil (Optatus palmaris) causes high losses to the soursop production in Mexico. Damage occurs when larvae and adults feed on the fruits; however, there is limited research about control strategies against this pest. However, pheromones provide a high potential management scheme for this curculio. Thus, this research characterized the behavior and volatile production of O. palmaris in response to their feeding habits. Olfactometry assays established preference by weevils to volatiles produced by feeding males and soursop. The behavior observed suggests the presence of an aggregation pheromone and a kairomone. Subsequently, insect volatiles sampled by solid-phase microextraction and dynamic headspace detected a unique compound on feeding males increased especially when feeding. Feeding-starvation experiments showed an averaged fifteen-fold increase in the concentration of a monoterpenoid on males feeding on soursop, and a decrease of the release of this compound males stop feeding. GC-MS analysis of volatiles identified this compound as α-terpineol. Further olfactometry assays using α-terpineol and soursop, demonstrated that this combination is double attractive to Annonaceae weevils than only soursop volatiles. The results showed a complementation effect between α-terpineol and soursop volatiles. Thus, α-terpineol is the aggregation pheromone of O. palmaris, and its concentration is enhanced by host-plant volatiles.

Tetranychus urticae (Koch) (Trombidiformes: Tetranychidae) is a cosmopolitan spider mite species that infests more than 900 species of plants, including commercial species. Tetranychus cinnabarinus (Boudreaux) is characterized by a red coloration, in contrast to the green-colored T. urticae. Both are occasionally found coexisting in warm environments, and, for that reason, they are considered by some to be synonyms. In this study, we identified specimens of the two morphospecies using optical and electron microscopy and amplification of a segment of the mitochondrial cytochrome oxidase I (COI) gene. Bioassays determined the level of susceptibility and survival of both morphospecies when they were infected with the entomopathogenic fungus Neozygites floridana (Weiser and Muma). For the evaluation of the susceptibility of these morphospecies to N. floridana, bioassays were conducted under conditions of 25 ± 2°C, 60 ± 5% relative humidity, and a 12:12-h photoperiod regime. From these bioassays, we found that T. cinnabarinus was less susceptible to N. floridana and that there is a higher level of fertility, survival, and development in the T. cinnabarinus than in the T. urticae mites. Within a mass rearing system, T. cinnabarinus appears be a more efficaceous functional food for predatory mites, such as Phytoseiulus persimilis (Athias-Henriot) (Mesostigmata: Phytoseiidae), than T. urticae to support rearing and release of biological agents for integrated pest management.