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

The Mediterranean fruit fy 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 toward adults. Among the extracts tested, only R. graveolens elicited signifcant diferences 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. Ruta graveolens extract elicited a signifcant insecticidal activity, confrmed to be dose-dependent. LD50 and LD90 concentrations were 3.64 and 6.01% (v/v), respectively. To our knowledge, this is the frst 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 medfy "attract and kill" control strategies.