Coffee crop weeds: refuge and food source for pests’ natural enemies

Weeds in coffee crops have diverse ecosystem services, such as sheltering and feeding natural enemies of pest insects. This study aimed to identify the potential of coffee weeds as food and refuge for natural enemies in shaded and sun coffee crops. Weeds were sampled in a 100 m transect installed in each type of coffee crop. Malaise traps and sweep-nets were both used to capture insects every 15 days for five months. After identifying the dominant weeds, observations and a direct recollection of insects were carried out at three different hours during three days. Faunistic analyses were performed, as well as the Bray and Curtis similarity analysis and the Student's t test. Emilia sonchifolia, Acmella oppositifolia, Bidens pilosa were predominant in the free exposure sun plantation coffee crops and Commelina diffusa, Salvia palifolia, Stachytarpheta cayennensis in under shade coffee crops. High insect activity was found between 11:30 am-12:00 pm. In these weeds, we found about 15 families, the most important were Formicidae, Braconidae, and Coccinellidae. We concluded that the shaded coffee crops exhibited a natural enemy community similar to that of the sun. Through this exploratory study, we verified that weeds harbor a diversity of natural enemies important to the coffee agroecosystems.

Amalgamation and Characterization of Copper Nanoparticles Alleviated With Stachytarpheta Cayennensis and Its Anti-cancer Activity in Both in Vitro and in Vivo Animal Model

Melanoma is an extremely malignant skin cancer with a probability of metastasis and accountable for the mainstream skin associated mortality. In the present study, we described the novel usage of Stachytarpheta cayennensis mediated copper nanoparticles and its anti-cancer activity in both in vitro and in vivo model of skin cancer. The synthesis of Cu-NPs was confirmed using UV-absorbance peak values ranging from 325-345 nm. The size of the nanoparticles was around 90nm, as deduced by the dynamic light scattering study.Furthermore, transmission electron microscopy (TEM) established that the morphology of the copper particles. Cytotoxicity of Cu-NPs of Stachytarpheta cayennensis illustrates the toxicity level of Stachytarpheta cayennensis. Also, the anti-cancer potential of Cu-NPs was evaluated in A375 cells. In experimental animals, body biochemical parameters like SOD, CAT, GSH were diminished in DMBA induced animals while Cu-NPs treatment raised the levels of the aforementioned enzymatic antioxidants compared to the control animals. Additionally, cytotoxicity assay, mitochondrial membrane potential (MMP), cell adhesion analysis, and the estimation of reactive oxygen species (ROS) in the presence of Cu-NPs was evaluated by standard protocols. The present study's outcomes confirm the defensive and valuable effects of copper loaded Stachytarpheta cayennensis against DMBA induced skin melanoma, animal model.

Extratos alcoólicos de gervão (Stachytarpheta cayennensis) causam alteração anatômica em plântulas de pepineiro

A alelopatia é uma estratégia da planta para sua defesa e delimitação territorial, muito comum em plantas daninhas. O gervão (Stachytarpheta cayennensis) é uma espécie de planta daninha frequente em áreas de cultivo e urbanas na região amazônica do Brasil. Poucos trabalhos sobre alelopatia têm destacado as alterações anatômicas que os metabólitos secundários causam nas plantas afetadas. O objetivo desse trabalho foi analisar a ação alelopática de cinco concentrações de extrato alcoólico (0; 0,5; 1; 2; e 4%) de S. cayennensis a nível de alterações anatômicas em plântulas de Cucumis sativus. Os resultados evidenciaram aumento de espessura nas estruturas anatômicas dos órgãos analisados de pepino em extratos aquosos e alcoólicos, demonstrando acentuado espessamento conforme o aumento das concentrações dos extratos da espécie em estudo. A confirmação de que a liberação dessas substâncias intervêm no desenvolvimento de C. sativus serve como importantes informações a serem utilizadas no desenvolvimento de estratégias alternativas ao uso de herbicidas em outras culturas, visando o manejo ecológico de plantas daninhas.

Insectos benéficos asociados a plantas arvenses atrayentes en agroecosistemas del Piedemonte de la Orinoquia Colombiana

Se estudió la biodiversidad de insectos benéficos asociados a plantas arvenses en agroecosistemas de cacao, guanábana y arroz. Se realizaron muestreos en cinco especies de plantas arvenses asociadas a los agroecosistemas: Crotalaria striata, Indigofera hirsuta, Hyptis capitata, Melampodium divaricatum y Stachytarpheta cayennensis. Los insectos se colectaron mediante muestreos sistemáticos con red entomológica y observaciones directas a través de un transecto lineal. Se realiza por primera vez un inventario detallado de la diversidad de insectos benéficos asociada a agroecosistemas del departamento del Meta, compuesta por 66 especies/morfoespecies. Se reportan datos de interés de diez especies, entre ellos la ampliación del rango de distribución de ocho especies para la Orinoquia, así como el registro de dos nuevos géneros para Colombia: Myzinum (Hymenoptera: Tiphiidae) y Chaetogaedia (Diptera: Tachinidae). Se constata una amplia biodiversidad taxonómica y ecológica de insectos benéficos en estos ecosistemas transformados, diversidad entomológica asociada especialmente a la presencia de plantas arvenses que actúan como fuentes de alimentos suplementarios y sitios de refugio para estos insectos. Este estudio pretende aportar datos de interés para el manejo integrado de plagas, programas de restauración ecológica y conocimiento de la biología de las especies registradas.