The composition of a chloroform seed extract of C. papaya was determined by GC-MS. Nineteen compounds were identified, with oleic (45.97%), palmitic (24.1%) and stearic (8.52%) acids being the main components. The insecticidal and insectistatic activities of the extract and the three main constituents were tested. Larval duration increased by 3.4 d and 2.5 d when the extract was used at 16,000 and 9,600 ppm, respectively, whereas the pupal period increased by 2.2 d and 1.1 d at the same concentrations. Larval viability values were 0%, 29.2%, and 50% when the extract was applied at 24,000, 16,000, and 9,600 ppm, respectively; pupal viability was 42.9% and 66.7% at 16,000 and 9,600 ppm; and pupal weight decreased by 25.4% and 11.5% at 16,000 and 9,600 ppm. The larval viability of the main compounds was 33.3%, 48.5%, and 62.5% when exposed to 1,600 ppm of palmitic acid, oleic acid, or stearic acid, respectively.

Essential oils can be used as an alternative to using synthetic insecticides for pest management. Therefore, the insectistatic and insecticidal activities of the essential oil of aerial parts of Salvia ballotiflora (Lamiaceae) were tested against the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae). The results demonstrated insecticidal and insectistatical activities against this insect pest with concentrations at 80 µg·mL . This oil also increased the duration of the larval phase by 5.5 days and reduced the pupal weight by 29.2% withrespect to the control. The GC-MS analysis of the essential oil of S. ballotiflora showed its main components to be caryophyllene oxide (15.97%), and β-caryophyllene (12.74%), which showed insecticidal and , respectively.

Entomopathogenic fungi (EF) are recognized biological control agents of insects. Basically, the entomopathogenic fungi pathogen activity depends on the ability of its enzymatic equipment, consisting of lipases, proteases and chitinases, which are in charge of breaking down the insect's integument. Lipases are the first enzymes synthesized by the entomopathogenic fungi. Recently, a cytochrome P450 subfamily, referred as CYP52XI and MrCYP52 has been identified in Beauveria bassiana and Metarhizium robertsii, respectively. These break down long-chain alkenes and fatty acids to become initial nutrients. Subsequently, subtilisin type (Pr1) proteases sintetize; these enzymes are considered as virulence indicators and they are regulated by a signal transduction mechanism activated by the protein kinase A (PKA) mediated by AMPc. Through the employment of genetic engineering, it has been possible to increase virulence producing Pr1 recombinants with Androctonus australis neurotoxins or with chitinases, reducing the insect's time of death. In the course of time, the Pr1 protease gene has presented evolutionary adaptations by gene duplication or horizontal transfer infecting different orders of insects. In the same way, the entomopathogenic fungi chitinases have presented a functional diversification. Currently, these have been phylogenetically classified into three subgroups, in accordance to the catalytic site domain and the chitin binding domain. The chitinolytic activity has increased through a directed evolution processes and genetic recombination with Bombyx mori chitinase. Recently, enzymes have been employed as control agents for insects and phytopathogenic fungi (disease originator) opening new potentialities in order to improve the entomopathogenic fungi use. Solid state fermentation is a bioprocess that would produce at great scale enzymes and some other metabolites in grade of increasing the entomopathogenic fungi virulence, in the control of insects and potentially in some

Plant extracts can be used as an alternative to synthetic insecticides for the control of insect pests. Based on this knowledge, juvenomimetic and insecticidal activities of n-hexane extracts of the aerial parts of Senecio salignus DC. (Asteraceae) and Salvia microphylla Kunth (Lamiaceae) collected in Mexico were evaluated against 1st instar larvae of Spodoptera frugiperda Smith & Abbot (Lepidoptera: Noctuidae). Senecio salignus extract showed insecticidal activity at 500 ppm, resulting in larval mortality of 52.5% and pupal mortality of 62.5%. Salvia microphylla extract at the same concentration caused larval mortality of 65.0% and pupal mortality of 82.5%. The LC50 was 440 ppm for S. salignus extract and 456 ppm for S. microphylla extract based on the total larval period. The juvenomimetic activity of S. salignus extract at 500 ppm increased the duration of the larval period to 17.3 d and of the pupal period to 1.4 d. It also reduced pupal weight by 34.7% with respect to the control (241 mg). For S. microphylla extract at 500 ppm, the duration of the larval and pupal periods were increased by 2.0 and 12.1 d, respectively, and the pupal weight was reduced by 14.1% with respect to the control (243 mg). The major compounds of S. salignus extract were γ-sitosterol, palmitic acid, lupeol, and β-amyrin, and those of S. microphylla extract were oleic acid, γ-sitosterol, (Z,Z,Z)-9,12,15-octadecatrien-1-ol, and palmitic acid. These results indicate that both extracts have potential to be used to control S. frugiperda due to their juvenomimetic and insecticidal activities.

Antifungal composite edible coatings (ECs) formulated with pregelatinized potato starch (PPS, 1.0-2.0 % w/w) as biopolymer, glyceryl monostearate (GMS, 0.5-1.5 %, w/w) as hydrophobe, glycerol (Gly, 0.5-1.5 %, w/w) as plasticizer, and sodium benzoate (SB, 2 % w/w) as antifungal agent were optimized using the Box-Behnken response surface methodology to extend the postharvest life of "Orri" mandarins. The second order polynomial models satisfactorily fitted the experimental data, with high values of the coefficient of determination for the different variables (R2>0.91). The individual linear effect of GMS concentration was significant in all the responses evaluated, whereas PPS only affected emulsion viscosity, fruit tacking, and weight loss of coated mandarins. Gly only affected acetaldehyde content in the juice of coated mandarins when interacted with PPS and in the quadratic effect. The optimum concentrations of PPS, GMS, and Gly for the starch-based EC based on maximum fruit quality and required emulsion properties were predicted to be 2.0, 0.5 and 1.0 % (w/w), respectively. The optimal EC reduced weight loss of mandarins and created a modified atmosphere within the fruit without negatively affecting the overall acceptability of the fruit. On the other hand, the optimized antifungal EC containing SB significantly reduced postharvest green and blue molds and sour rot on mandarins artificially inoculated with the pathogens Penicillium digitatum , Penicillium italicum and Geotrichum citri-aurantii , respectively. Therefore, the optimized antifungal EC showed potential to control the main postharvest diseases and maintain the overall quality of "Orri" mandarins and could be a suitable alternative to commercial citrus waxes formulated with conventional chemical fungicides.

No abstract

No abstract

No abstract