Sugarcane spittlebugs are considered important pests in sugarcane crops ranging from the southeastern United States to northern Argentina. To evaluate the effects of climate variables on adult populations of Aeneolamia varia (Fabricius) (Hemiptera: Cercopidae), a 3-yr monitoring study was carried out in sugarcane fields at week-long intervals during the rainy season (May to November 2005–2007). The resulting data were analyzed using the univariate Forest-Genetic method. The best predictive model explained 75.8% variability in physiological damage threshold. It predicted that the main climatic factors influencing the adult population would be, in order of importance, evaporation; evapotranspiration by 0.5; evapotranspiration, cloudiness at 2:00 p.m.; average sunshine and relative humidity at 8:00 a.m. The optimization of the predictive model established that the lower and upper limits of the climatic variables produced a threshold in the population development rate of 184 to 267 adult insects under the agroecological conditions of the study area. These results provide a new perspective on decision-making in the preventive management of A. varia adults in sugarcane crops.

Genotype by environment interactions for damage caused by AbstractDiatraea spp. (Lepidoptera: Crambidae) or sugarcane stem borers are important sugarcane pests in Venezuela. The use of resistant cultivars is part of an integrated management to control these insects in many countries. The aim of this study was to evaluate a group of sugarcane genotypes for Diatraea damage in several environments, and to assess the interaction among damage caused by Diatraea and yield components. Data were collected from five sugarcane field trials located in plots belonging to the Venezuelan Sugarcane Breeding Program. Twenty genotypes were evaluated for Diatraea damage in a completely randomized block design with three replicates. AMMI and GGE biplot analyses were executed for infestation intensity (II). Genotypes that showed best stability, good yield and low damage from Diatraea spp. across environments were V99-236, V00-50 and V99-190. Cultivar CP74-2005 was the most affected by injuries of sugarcane stem borers throughout locations. Intensity of infestation (II) and index of damage (ID) were highly associated. Furthermore, high intensity of infestation (II) and index of damage (ID) caused by Diatraea disturbed the Pol % cane of the genotypes.Keywords: Genetic phenomena; control methods; AMMI; GGE biplot; stable resistance; mega-environments. ResumenLos taladradores de la caña de azúcar Diatraea spp. (Lepidoptera: Crambidae) son importantes plagas de la caña de azúcar en Venezuela. El uso de cultivares resistentes forma parte del manejo integrado para el control de esos insectos en muchos países. Los objetivos de este trabajo fueron evaluar un grupo de genotipos de caña de azúcar a los daños de Diatraea spp. en varios ambientes y determinar la interacción entre los daños causados por el complejo de insectos del genero Diatraea y los componentes de rendimiento. Los datos fueron recolectados en cinco localidades evaluadas por el programa venezolano de mejoramiento de la caña de azúcar. Veinte genotipos fueron evaluados al daño de Diatraea spp. en cinco localidades en un diseño de bloques al azar con tres repeticiones. La tasa de intensidad de infestación (II) causada por Diatraea spp. fue analizada mediante los modelos AMMI y GGE biplot. Los genotipos más recomendados por su estabilidad, buen rendimiento y menor daño por taladradores del tallo a través de los ambientes fueron: V99-236, V00-50 y V99-190. El cultivar CP74-2005 fue el más afectado por el daño de Diatraea spp. a través de las localidades. La intensidad de la infestación (II) y el índice de daño (ID) estuvieron altamente asociados. Altas tasas de intensidad de infestación (II) e índice de daño (ID) causado por Diatraea afectaron el Pol % caña de los genotipos. Palabras clave: Fenómeno

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