Pheromone blends and trap designs can affect catches of Sesamia nonagrioides Lef. (Lep., Noctuidae) males in maize fields

Among lepidopteran insects, the female-produced sex pheromones are the most widely used chemical stimuli for pest management by (i) mating disruption, and (ii) monitoring adult insect populations in agricultural crops. Sesamia nonagrioides is one of the main pests on maize crops around the Mediterranean area and monitoring adult populations with synthetic sex pheromone is of great interest. The technique used involved field trapping with synthetic pheromone blend. The reliability of the technique is directly related to the trap shape and pheromone blends. Universal Moth Trap(R) (UM trap. Biosystemes, france) and Service Regional de la protection des Vegetaux (SRPV) traps baited with either synthetic pheromone blend or virgin females were evaluated in two commercial maize fields (var.cecilia) (Belleserre. Tarn. France) to determine the potential use of synthetic lures in monitoring S. nonagrioides populations in maize field. The study showed that SRPV traps baited with synthetic pheromone blend caught significantly more S. nonagrioides males than UM traps baited with the same blend, indicating the efficiency of the SRPV traps in monitoring field population of S. nonagrioides. The study also showed that the synthetic pheromone-baited SRPV trap caught three times less adult males than the same traps baited with virgin females indicating that the synthetic blend was less attractive than the natural blend released by virgin females. However. despite the lower number of catches in the SRPV traps baited with synthetic pheromones there was a significant and positive relationship between the number of catches in SRPV traps baited with the synthetic pheromone and with the females. This result indicates that synthetic pheromones can be used as baits in SRPV traps to monitor S. nonagrioides adult population in commercial maize crops. Nevertheless, to use the synthetic pheromone to monitor S. nonagrioides population effectively in the field, further refinement and improvement of the synthetic blend should be carried out in order to obtain a blend that is equally as attractive as the natural blend released by virgin females.