Preliminary data on mating disruption of red scale in Portugal

Abstract

The use of Red Scale DownTM for mating disruption (MD) and pest management of the red scale (CRS), Aonidiella aurantii (Maskell), was evaluated in a field experiment carried out in 2007, in the Southern region of Portugal (Algarve). A total of 250 dispensers of Red Scale DownTM per hectare were installed in four 1-2 ha sweet orange orchards, in two applications (March and ca. 3 months later). Each dispenser contains 0.4 mg of the active ingredients, i.e., (3S, 6R)-3-methyl-6-isopropenyl- 9-decen-1-yl acetate (0.041%) and (3S, 6S)-3-methyl-6-isopropenyl-9-decen-1-yl acetate (0.025%). Three modalities of RS management were compared in each orchard: 1) MD; 2) MD + 1 insecticide application (chlorpyriphos) RS; 3) MD + 2 or 3 insecticide applications (chlorpyriphos, mineral oil). Male captures in pheromone traps were monitored every two weeks. The level of fruit infestation by CRS was estimated before the experiment and in the end of season in order to evaluate the effectiveness of each management modality. The results suggest that mating disruption of CRS may be an effective tactic for pest management of CRS populations when infestation levels are low.