No abstract

One of the main pests of commercial rose crops in Colombia is the phytophagous mite Tetranychus urticae Koch. To manage this pest, synthetic chemicals have traditionally been used, some of which are well known to be potentially toxic to the environment and humans. Therefore, alternative strategies for pest management in greenhouse crops have been developed in recent years, including biological control with natural enemies such as parasitoids, predators and entomopathogenic microorganisms as well as chemical control using plant extracts. Such extracts have shown toxicity to insects, which has positioned them as a common alternative in programs of integrated pest management. The objective of this study was to evaluate the effect of an unfractionated ethanolic extract of Cnidoscolus aconitifolius leaves on adult females of T. urticae under laboratory conditions. The extract was chemically characterized by recording its metabolic profile via liquid chromatography coupled to mass spectrometry, along with tentative metabolite identification. The immersion technique and direct application to rose leaves were used to evaluate the effects of seven doses (10–2,000 µg/mL) of the ethanol extract of C. aconitifolius leaves on T. urticae females under laboratory conditions. The mortality and oviposition of individuals were recorded at 24, 48 and 72 h. It was found that the C. aconitifolius leaf extract reduced fertility and increased mortality in a dose-dependent manner. The main metabolites identified included flavonoid- and sesquiterpene-type compounds, in addition to chromone- and xanthone-type compounds as minor constituents with potential acaricidal effects.

The spider mite, Tetranychus urticae Koch, is one of the main pests of greenhouse cut flowers. Different alternative strategies have been pursued for the management of this pest to avoid the excessive use of chemical products of high toxicological levels. Within these strategies is included the use of ethanolic and oily extracts from plants belonging to various plant families exhibiting acaricidal activity. For this reason, the objective of this work was the selection and evaluation of some botanical extracts from native plants in Colombia that can be used to manage T. urticae. Thus, as part of our research on bioacaricides, the direct effect of five plant extracts on the mortality and fecundity of the egg, larva, nymph and adult stages of the mite and the chemical composition of each extract was additionally determined by high performance liquid chromatography coupled with mass spectrometry (LC/MS). It was found that the test extracts showed a low efficiency on eggs, larvae and nymphs of T. urticae, since mortalities did not reach 50%. However, in the case of adults, the extracts of Cnidoscolus aconitifoluis, Copaifera oficinalis and Anadenanthera peregrina could be suggested as promissory extracts for the management of adults of T. urticae, since they caused mortalities greater than 60% and reduced female fecundity. The main secondary metabolites identified were flavonoids, whose presence in test extracts would be associated with the acaricidal potentiality referred to.

Esta cartilla describe la forma en que un apicultor debe tomar muestras en colmenas para obtener un diagnóstico adecuado que le sirva como herramienta en la toma de decisiones para el manejo sanitario y el mejoramiento de la productividad y el bienestar de las abejas.

Esta publicación le brinda al productor, en un lenguaje natural de fácil entendimiento, algunos aspectos clave para el cultivo de café. Está enfocado en temáticas como el clima, el uso de suelo, las plagas y las enfermedades, con conocimientos actualizados con el fin de mejorar las prácticas en su actividad productiva.