Citrus leafminer 'Phyllocnistis citrella' (Lepidoptera: Gracilariidae) and its parasitoids: Ten years after the implementation of Classical Biological Control in Spain

Abstract

The citrus leafminer Phyllocnistis citrella is a pest which originates from eastern and southern Asia and posed a serious threat to the citrus industry of the Mediterranean region upon its introduction in Spain in 1993 and its subsequent spread. Today, fourteen years after the introduction of the pest and the following implementation of a Classical Biological Control Programme comprising the introduction of six exotic parasitoid species (Ageniaspis citricola, Quadrastichus sp., Semielacher petiolatus, Galeopsomyia fausta, Cirrospilus ingenuus and Citrostichus phyllocnistoides) for the control of the pest, the citrus leafminer does not cause damage of economic importance on mature trees whereas a new balance of the parasitoid complex-pest system has established in the area of release. Monitoring of the incidence and quantification of the impact of both exotic and indigenous parasitoids and predators on the control of the citrus leafminer in mandarin orchards at three different locations in Eastern Spain showed that the exotic parasitoid Citrostichus phyllocnistoides is the predominant species, holding the 99.42% of the total in the survey. Indigenous parasitoid species represented minor percentages of the total: Pnigalio spp. (0.33%), Cirrospilus brevis (0.06%), Sympiesis gregori (0.06%), Pteromalidae species (0.11%) and Diglyphus sp. (0.03%). The results provide insights into the interactions between the exotic and the indigenous natural enemies of the citrus leafminer and will contribute on the evaluation of the Classical Biological Control Programme.