Distribución espacial de Premnotrypes vorax (Hustache) (Coleoptera: Curculionidae) en cultivos de papa

Abstract

<p>La distribución espacial de los insectos plaga proporciona información importante para optimizar los programas de manejo y reducir la aplicación de insecticidas. En este trabajo se estudió la dinámica espacial de los adultos del gusano blanco Premnotrypes vorax en dos cultivos comerciales de papa durante 18 semanas. Durante este período se registró el número de adultos capturados semanalmente en 25 trampas de caída dispuestas en un diseño en cuadrícula. Además, se realizó la evaluación de los niveles de daño ocasionados por el insecto en tubérculos cosechados al final del ciclo de cultivo. Utilizando el método de análisis espacial mediante índices de distancia (Sadie), se determinaron: 1.- Los patrones y estabilidad temporal de la distribución espacial de los adultos, y 2.- La asociación espacial entre la distribución de los adultos y la distribución de la incidencia de daño en tubérculos. Los análisis sugieren una distribución agregada de los adultos en la mayoría de fechas evaluadas y una estructura espacial temporalmente estable. La asociación espacial entre el patrón de distribución de los adultos con la incidencia de daño en tubérculos fue significativa (p < 0,025). Estos resultados sugieren que es posible utilizar estrategias de control dirigidas hacia los focos específicos de infestación, para optimizar el manejo de la plaga y reducir la aplicación de insecticidas.</p><p> </p><p><strong>Spatial distribution of Premnotrypes vorax (Hustache) (Coleoptera: Curculionidae) in potato crops.</strong></p><p>The spatial distribution of insect pest provides important information that can optimize the management programs and reduce insecticide applications. In this work, the spatial dynamics of the Andean weevil Premnotrypes vorax, were studied in two commercial potato crops for 18 weeks. During this period, the adult number was registered weekly in 25 pitfall traps, which were arranged in a quadrangular design. Moreover, the pest injury levels were evaluated in harvested tubers at the end of the crop cycle. Using the Spatial analysis by distance index (Sadie) method, were determined: (1) the patterns and temporal stability of the spatial distribution of adults and, (2) the spatial association between the distribution of adults and the distribution of damage incidence in tubers. The analyses suggested an aggregated pattern of adults in most of the evaluation dates and a temporally stable spatial structure. The spatial association between the distribution patterns of adults with the damage incidence in tubers was significant (p < 0.025). These results suggest that it is possible use spatially targeted control strategies to optimize the pest management and reduce insecticide applications.</p>

Distribución espacio-temporal de Diatraea spp. (Lepidoptera: Crambidae) en el valle del río Cauca, Colombia

“…Comportamientos espaciales similares a los detectados para las poblaciones de Diatraea spp. han sido documentados para otras especies de insectos plaga, como es el caso de Jacobiasca lybica (Hemiptera: Cicadellidae) en viñedos (Ramírez et al 2002) y Premnotrypes vorax (Coleoptera: Curculionidae) en cultivos de papa (Pérez-Álvarez et al 2010).…”

Identification of Cry toxin receptor genes homologs in a de novo transcriptome of Premnotrypes vorax (Coleoptera: Curculionidae)

“…Adult insects of P. vorax feed on the plant leaves, but the most important damage with economic relevance is caused by the larvae, which feeds on the tubers, making galleries that affect the quality of the product showing external visible damage [6], resulting in up to 90% croploses due to the damaged tubers or to the complete crop destruction, especially when the larvae population is high [7]. It was reported that the life cycle of P. vorax can last up to nine months [8], indicating that it has only one or two generations per year.…”

“…Historically, the control of this insect by indigenous farmers involves extended crops rotation, special separation between fields, use of plant barriers, and chemical control with highly toxic chemical insecticides such as carbamates, pyrethroids, organophosphates and carbofuran that are applied at the time of potato planting. However, usually these insecticide treatments fail to penetrate deep in the soil, where the potato tuber grows [6,9]. In Colombia, more than US $22 million are spent each year for spraying insecticides against P. vorax [10].…”

De novo transcriptome assembly of Premnotrypes vorax (Coleoptera: Curculionidae)

“…P. vorax is distributed in South America, principally in Colombia, Ecuador, Venezuela and Peru with registries as one of the most important pests of potato (Solanum tuberosum) crops (Pérez et al, 2009). Adult insects feed on the plants and cause damage along the edges of the leaves, but the larvae also make tunnel-shaped lesions in the tubers causing externally visible damage (Pérez-Álvarez et al, 2010). This insect can cause commercial loses up to 80% of damaged tubers or the complete destruction of the potato crop, especially with high larvae populations (ICA, 2011).…”