Ecologically controlling insect and mite pests of tea plants with microbial pesticides: a review.

Insect and mite pests are damaging stressors that are threatening the cultivation of tea plants, which result in enormous crop loss. Over the years, the effectiveness of synthetic pesticides has allowed for its prominent application as a control strategy. However, the adverse effects of synthetic pesticides in terms of pesticide residue, environmental contamination and insect pest resistance have necessitated the need for alternative strategies. Meanwhile, microbial pesticides have been applied to tackle the damaging activities of the insect and mite pests of tea plants, and their performances were scientifically adjudged appreciable and environmental friendly. Herein, entomopathogenic microbes that were effective against tea geometrid (Ectropis obliqua Prout), tea green leafhopper (Empoasca onukii Matsuda), paraguay tea ampul (Gyropsylla spegazziniana), tea mosquito bug (Helopeltis theivora Waterhouse) and red spider mite (Oligonychus coffea Nietner) have been reviewed. The current findings revealed that microbial pesticides were effective and showed promising performances against these pests. Overall, this review has provided the basic and integrative information on the integrated pest management (IPM) tool(s) that can be utilized towards successful control of the aforementioned insect and mite pests.

Evaluación de la actividad repelente de aceites esenciales de plantas Piperáceas del departamento de Chocó, Colombia / Evaluation of repellent activity of essential oils from plants Piperaceae Department of Chocó, Colombia

El objetivo de este trabajo fue determinar la composición química volátil del aceite esencial de varias especies de Piperáceas (Piper dilatatum, Piper aduncum, Piper divaricatum, Piper sp, Piper sanctifelicis) y la actividad repelente de ellos contra el gorgojo de granos almacenados Tribolium castaneum Herbst. Los aceites esenciales se obtuvieron por hidrodestilación, la separación e identificación de los componentes volátiles se realizó por cromatografía de gases acoplada a espectrometría de masas y para la evaluación de la actividad repelente se empleó el método de área de preferencia. Los compuestos mayoritarios encontrados en Piper dilatatum fueron el apiol 89,0% y trans-cariofileno (3,5%); en Piper divaricatum, eugenol (37,5%) y metil eugenol (36,3%); Piper sp, alpha-gurjuneno (o guaieno) (24,9%) y elemol (14,2%); Piper sanctifelicis, Delta-3-careno (35,3%) y limoneno (27,1%); Piper aduncum, dilapiol (48,2%) y 1,8 cineol (11,4%). Los porcentajes de repelencia de los aceites esenciales a una concentración de 1 µL/cm2, a un tiempo de exposición de 2 horas frente al T. castaneum fueron: Piper aduncum (99%), Piper sp (96%), Piper dilatatum (82%), Piper divaricatum (76%), Piper santifelicis (33%) (AU)

The objective of this study was to determine the volatile chemical composition of the essential oil of various species of Piperaceae (Piper dilatatum, Piper aduncum, Piper divaricatum, Piper sp, Piper sanctifelicis) and repellent activity of them against weevil stored grain Tribolium castaneum Herbst . Essential oils were obtained by hydrodistillation, the separation and identification of volatile components was performed by gas chromatography-mass spectrometry and to evaluate the repellent activity the area method was used preferably. The major compounds found in Piper dilatatum were 89.0% and apiol trans-caryophyllene (3.5%); Piper divaricatum, eugenol (37.5%) and methyl eugenol (36.3%); -gurjunene (or guaiene) (24.9%) and elemol (14.2%);Piper sp, Piper sanctifelicis, -(35.3%) and limonene (27.1%);3-carene Piper aduncum, dilapiol (48.2%) and 1,8 cineole (11.4%). Percent repellency of essential oils at a concentration of 1 uL / cm2, to an exposure time of 2 hours against T. castaneum were: Piper aduncum (99%), Piper sp (96%), Piper dilatatum (82 %), Piper divaricatum (76%), Piper santifelicis (33%)

Environmental biosafety and transgenic potato in a centre of diversity for this crop.

The Nuffield Council on Bioethics suggests that introgression of genetic material into related species in centres of crop biodiversity is an insufficient justification to bar the use of genetically modified crops in the developing world. They consider that a precautionary approach to forgo the possible benefits invokes the fallacy of thinking that doing nothing is itself without risk to the poor. Here we report findings relevant to this and other aspects of environmental biosafety for genetically modified potato in its main centre of biodiversity, the central Andes. We studied genetically modified potato clones that provide resistance to nematodes, principal pests of Andean potato crops. We show that there is no harm to many non-target organisms, but gene flow occurs to wild relatives growing near potato crops. If stable introgression were to result, the fitness of these wild species could be altered. We therefore transformed the male sterile cultivar Revolucion to provide a genetically modified nematode-resistant potato to evaluate the benefits that this provides until the possibility of stable introgression to wild relatives is determined. Thus, scientific progress is possible without compromise to the precautionary principle.