15BACKGROUND: The tomato leaf miner (Tuta absoluta Povolny) has rapidly colonized the whole Mediterranean and South-Atlantic coasts of Spain, and it has become a key problem in both outdoor and greenhouse crops. New control methods compatible with biological control are required and mating disruption appears to be a perfect method in current agriculture as it is an environmentally-friendly and residue-free technique. IPM 20 packages tested have included the use of pheromones to detect populations, but there has not been much previous research on mating disruption of T. absoluta. In this work, pheromone doses varying from 10 to 40 g ha -1 , emitted at a constant rate over four months, were tested in greenhouses with different levels of containment, in order to evaluate the efficacy of mating disruption on T. absoluta. 25 RESULTS: Trials on containment level revealed that the flight of T. absoluta was satisfactorily disrupted with an initial pheromone dose of 30 g ha -1 , and levels of damage did not significantly differ from those in reference plots with insecticide treatments. Later efficacy trials confirmed our previous experiences, and release studies showed that control of damage and flight disruption were taking place when releasing, 30 at least, 85 mg pheromone per ha per day.CONCLUSION: Effective control using pheromone application against T. absoluta can be achieved, in greenhouses with high containment levels, for 4 months, with initial doses of 30 g ha -1 . Further research must be conducted in order to evaluate the prospect of outdoor application of mating disruption systems. 35

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Considerable efforts have been devoted to understanding the courtship behavior and pheromone communication of medflies; however, the sex pheromone composition is still a controversial subject. The discovery of new components affecting medfly behavior would be of interest for medfly control methods based on semiochemicals. This work describes volatile compounds emitted by Ceratitis capitata collected using solid phase microextraction. The volatile study was conducted according to an experimental design with three factors (sex, age, and mating status) assumed to be relevant for better understanding the chemical communication. Emission data were treated by means of principal component analysis, a statistical methodology not previously applied to the study of volatiles emitted by fruit flies. The characterization of emission patterns could be useful for the selection of compounds to be further investigated in biological assays to improve knowledge of the key semiochemicals involved in medfly behavior.

Traditional chemical control against Chilo suppressalis Walker is currently being replaced in Spain by new methods based on pheromones. A key step to improve the efficacy of these methods is the determination of the optimum pheromone release rate, which is still uncertain for this pest. In this work, the pheromone release profile and the field performance of a new mesoporous dispenser was compared with a standard commercial dispenser. For this purpose, pheromone loads were extracted from field-aged dispensers and quantified by gas chromatography with flame ionization detector. In addition, a field trial was carried out with traps baited with one, two, or three mesoporous dispensers per trap, as well as with traps containing one standard dispenser. We found that the highest number of field catches did not correspond to the highest pheromone emission rate, which suggests a repellent effect of the insect if the emission is excessive. The results suggest that the attractant activity was maximized by emitting approximately 34 microg/d. The efficacy of the mesoporous dispenser and its possible improvements are discussed.

Abstract. The control of California red scale (Aonidiella aurantii Maskell) has encountered many difficulties, which have raised interest in alternative control methods. Up to now, the A. aurantii sex pheromone has been used only for monitoring. In a previous work we have described a biodegradable mesoporous pheromone dispenser for mating disruption. To verify the efficacy of these dispensers, three field trials were conducted and the results are shown in this paper. The study of the release profile of these dispensers revealed a mean pheromone emission value of 269 µg day -1 and levels of residual pheromone of 10% at the end of 250 days. During the 2 nd flight, an A. aurantii male catch reduction of 98% was achieved in the mating disruption plot of trial 1, 93.5% in trial 2 and 76.7 % in trial 3. During the 3 rd flight, reductions were 94.1, 82.9 and 68.1%in trials 1, 2 and 3 respectively. Considering damaged fruit with more than 5 scales, it was obtained a reduction of about 80% and 60% in the mating disruption plot of trial 2 and 3 respectively compared to an untreated plot, and a reduction of about 70% in trial 1 compared to an oil treated plot. Mating disruption has been found to be an efficient technique to control this pest, working equally well as a correctly sprayed oil treatment. Further studies are needed to improve the determination of the time of the dispensers' application and evaluate the effects of the pheromone on natural enemies.Capítulo II 2