Evaluación en campo del trampeo masivo de la mosca mediterránea de la fruta con Tripack® como alternativa a los tratamientos cebo con malatión en huertos de cítricos

The mass trapping technique based on the use of the female-targeted attractant lure Tri-pack® as an alternative to malathion bait-spraying (control treatment) was tested in two citrus orchards in the North of Tunisia against the Mediterranean fruit fly Ceratitis capitata during 2006 and 2007. Results of mass trapping trials in 2006 and 2007 indicated that adult males Medfly captures showed reductions respect to control of 37.62% and 40.2% respectively in mandarin orange variety (Citrus reticulata) orchard compared to 36.48% and 47.29% in Washington navel orange variety (Citrus sinensis) field. Fruit damage assessment showed significant differences between the mass trapping with Tripack® and malathion bait-spraying techniques in the reduction of the percentage of fruit punctures. The percentage of punctured fruit at harvest was significantly different between the treated and the control field in 2006 and in 2007 in the mandarin orange orchard. Nevertheless, in the Washington navel orange orchard, the percentage of punctured fruit at harvest was significantly different between the treated and the control field only in 2006. Thus, results obtained from this study showed that the mass trapping technique based on the use of the female-targeted lure Tri-pack® could be involved as an appropriate strategy for the control of the Medfly and is as effective as malathion bait spraying treatment without leaving pesticide residues on fruit.Se probó en dos huertos de cítricos, en el norte de Túnez en 2006 y 2007, la técnica del trampeo masivo utilizando el atrayente de hembras Tri-Pack® contra la mosca mediterránea de la fruta, Ceratitis capitata como alternativa a los tratamientos cebo con malatión, que constituye la forma convencional de control utilizada por los agricultores y que se utilizó como tratamiento control. En 2006 y 2007, en los ensayos de trampeo masivo las capturas de machos adultos del insecto se redujeron respecto el control, respectivamente, un 37,62% y un 40,2% en la variedad de mandarina (Citrus reticulata) en comparación con un 36,48% y un 47,29% en la variedad de naranja Washington navel (Citrus sinensis). Al evaluar los daños en los frutos se observaron diferencias significativas entre el trampeo masivo con Tripack® y los tratamientos cebo con malatión con una reducción de las picaduras en los frutos El porcentaje de frutos con picaduras en el momento de la cosecha fue significativamente diferente en las parcelas control y tratada en el huerto de mandarina tanto en 2006 como en 2007. Sin embargo, en el huerto de naranja Washington navel, el porcentaje de frutos con picaduras recolectados fue significativamente diferente entre el tratado y el control sólo en 2006. Por tanto, los resultados obtenidos en este estudio muestran que la técnica de trampeo masivo utilizando el atrayente de hembras Tri-Pack® podría ser una estrategia adecuada para el control de la mosca mediterránea de la fruta y es tan efectiva como el tratamiento cebo con malatión, pero sin dejar residuos de plaguicidas en la fruta

Behavior-modifying and insecticidal effects of plant extracts on adults of Ceratitis capitata (Wiedemann) (Diptera Tephritidae)

The Mediterranean fruit fly Ceratitis capitata is a major pest of fruit orchards worldwide. In order to develop control methods based on natural products, particularly required in organic farming, a laboratory study was carried out to evaluate the response of adults to leaf extracts from four plant species: Ruta graveolens, Eriobotrya japonica, Rubus ulmifolius and Ficus carica. Air dried leaf powders were subjected to an ethanolic cold extraction. Chemical composition was assessed by GC/MS analysis. Extracts were tested in laboratory bioassays to assess the electroantennographic (EAG) response, attraction/repellence toward ovipositing females and induced mortality towards adults. Among the extracts tested, only R. graveolens elicited significant differences compared to the control in all the bioassays. This extract, whose main volatile compounds were 2-nonanone and 2-undecanone (45% of the total), recorded the greatest EAG response, and stimulated a positive oviposition response compared to the control. R. graveolens extract elicited a significant insecticidal activity, confirmed to be dose-dependent. LD50 and LD90 concentrations were 3.64% and 6.01% (v/v) respectively. To our knowledge this is the first study reporting a single plant extract, from R. graveolens, acting as attractant and oviposition stimulant, and at the same time having insecticidal properties toward C. capitata adults. The incorporation of such extract or its components into food bait could be useful in medfly “attract and kill” control strategies