G. Heit, G. Cohen, and G. Mareggiani. 2008. Impact of odor signals on Cycloneda sanguinea (Coleoptera: Coccinellidae) searching behavior. Cien. Inv. Agr. 35(2):205-210.Volatile infochemicals generated by aphids, their host plants, or from the interaction between host plant and herbivore (herbivore-induced volatile plant compounds) are among the environmental stimuli used by predators to locate prey. The objective of this study was to evaluate the olfactometric response of the predator Cycloneda sanguinea (Coleoptera: Coccinellidae) to volatile infochemicals associated with the tomato plant, Lycopersicon esculentum Mill. (Solanaceae), and the aphid prey Myzus persicae Sulzer (Hemiptera: Aphididae). Predator behavior was evaluated in an airfl ow olfactometer at 24 ± 2ºC with 65 ± 10% relative humidity and a 16 h photoperiod. Latency time and the number of visits to the active chamber where the odor source was located were recorded. The odor sources studied were: a. thirty healthy aphids; b. uninfested tomato leaves; c. infested tomato with 30 healthy aphids; d. infested tomato leaves with 30 stressed aphids; e. thirty stressed aphids. C. sanguinea adults were strongly attracted to the odors of infested tomato leaves, but for the other odor sources, they did not visit active chambers more often than inactive chambers. C. sanguinea took less time to fi nd active chambers with tomato leaves infested with healthy aphids than to fi nd chambers with aphids or tomato leaves alone. These results suggest that C. sanguinea uses herbivore-induced volatile plant compounds as reliable indicators of herbivore infestation to locate prey.

G. Heit, V. Messina, G. Mareggiani, R. Cohen, and P. Carrizo. The use of actometry and electronic nose devices to assess the locomotor activity of two species of Coccinellidae (Coleoptera). Cien. Inv. Agr. 38(2):265-275. The effect of odor signals on the locomotor activity of Cycloneda sanguinea and Harmonia axyridis was evaluated using two different actometric devices. The purpose of the analysis was to differentiate between the responses elicited by direct contact with the substrates and the responses that occurred if the coccinellids were exposed only to volatiles and had no direct substrate contact. The odor profile of the environmental volatiles (semiochemicals) in the bioassays was analyzed using an electronic nose (Modular Sensor System Moses II). The treatments used included volatiles emitted by pepper leaves (healthy or infested with Myzus persicae), M. persicae molts and honeydew, and healthy leaves treated with an artificial inducer of the systemic acquired response to herbivory (AISAR). The results suggest that a specific stimulus linked to aphid-host interaction would trigger a distinctive locomotor activity pattern in H. axyridis, with or without any contact with the aphids or the host plant. In contrast, C. sanguinea was not able to differentiate between volatiles from infested or uninfected pepper leaves or to distinguish these volatiles from clean filter paper (control). If C. sanguinea was in contact with aphid-infested pepper leaves (regardless of the previous prey density), it moved slowly and scanned the area exhaustively; H. axyridis showed significantly reduced locomotor activity when it was in contact with aphid-infested pepper leaves or aphid molts and honeydew, all reliable signals of the presence of a food source. In both species, treatment with Actigard (AISAR: Acibenzolar-S-methyl) failed to evoke the behavioral response observed in the treatment with aphid-infested pepper plants. The study also demonstrated that the E-nose can differentiate among blends of volatiles released from cut healthy or aphid-infested pepper leaves.

SUMMARYLymantria dispar is a quarantine pest absent in South America. A regional phytosanitary surveillance plan was developed to control this pest due to its high risk of introduction through global commerce. The objective of this study was to estimate the potential distribution ranges of L. dispar in a new geographical area, using a deductive approach to prioritize areas for preventive monitoring. In South America, forest susceptibility was evaluated under different climate scenarios. In Argentina a phenology model was simulated. According to historical climatic conditions in South America, the areas with higher risk of establishment are the Andean forests from northern Argentina to Venezuela, the Brazilian Atlantic forest, littoral coastal areas of Uruguay and Argentina and the Mediterranean area of central and southern Chile. Based on estimations of IPCC, the effects of climate change would cause a reduction of the susceptible area to L. dispar invasion in future decades. Although there were statistically significant differences among the areas with high risk of invasion, estimated by the two methodological approaches, susceptible areas for preventive monitoring were identified.Key words: invasive species, climate change, phytosanitary risk. RESUMENLymantria dispar es una plaga cuarentenaria ausente de Sudamérica, para la que se ha elaborado un plan de vigilancia fitosanitaria regional, debido su elevado riesgo de introducción involuntaria a través del comercio. El objetivo de este trabajo fue estimar la distribución geográfica potencial de L. dispar en una nueva área utilizando un enfoque deductivo, a fin de priorizar ambientes en riesgo para su monitoreo preventivo. En Sudamérica se evaluó la susceptibilidad de la cobertura boscosa ante diferentes escenarios climáticos. A escala local, en Argentina, se simuló la fenología potencial de la especie. A base de las condiciones climáticas históricas de Sudamérica, L. dispar podría establecerse en los bosques andinos desde el norte de Argentina, hasta Venezuela, la mata atlántica brasileña, áreas costeras litorales de Uruguay y Argentina y el área mediterránea del centro y sur de Chile. Los efectos del cambio climático estimados por el IPCC, provocarían una disminución de este área susceptible en las próximas décadas. Aunque existieron diferencias significativas en la superficie clasificada como de mayor riesgo fitosanitario en las dos escalas de estudio (subcontinental vs. regional), se lograron identificar las principales áreas susceptibles para el monitoreo preventivo de L. dispar.Palabras clave: especie invasora, cambio climático, riesgo fitosanitario.

ResumenEl Huanglongbing (HLB), es la enfermedad de los cítricos más destructiva a nivel mundial, que en Sudamérica presenta una distribución restringida a algunos estados de Brasil. El objetivo del trabajo fue estimar los efectos del cambio climático en la distribución geográfica potencial de HLB en Sudamérica, mediante una técnica basada en el Análisis de Componentes Principales, que predice la aptitud ambiental de una especie a partir de la distancia euclidiana desde cualquier punto geográfico de Sudamérica hacia los sitios dónde HLB se ha establecido en Sudamérica. Para estimar los cambios en la distribución potencial de HLB ante un escenario de cambio climático, se consideró la Vía de Concentración Representativa 2,6, propuesta por el Quinto Informe de Evaluación del Intergovernmental Panel on Climate Change, generada por el modelo HadGEM2-ES, para las décadas de 2050 y 2070. A posteriori, se calculó el estadístico kappa de las capas resultantes contra una matriz de sitios con presencia de HLB en Brasil. Se utilizaron los softwares QGIS 2.12, IDRISI Selva e Infostat. El modelo estimó que los sitios con un elevado riesgo de establecimiento se distribuirían en el sur de Brasil, sudeste de Paraguay, región Noreste y zona oriental de la región Noroeste de Argentina y el centro-sur de Bolivia. Según las estimaciones del IPCC5, los efectos del cambio climático determinarían que a futuro, las áreas de elevado riesgo climático para el establecimiento de HLB, se desplazarían hacia el sudoeste de las áreas consideradas de mayor riesgo climático en la actualidad. According to the estimations of the Fifth Assessment Report of the IPCC and considering the RCP 2.6, the effects of climate change could determine that areas of climate risk for the establishment of HLB would be displaced towards the southwest of the areas considered riskier nowadays.