Abundance of natural enemies in citrus of the Iberian Peninsula: geographical distribution and seasonal trend

Abstract: We performed a sampling program in citrus orchards of the Iberian Peninsula to determine the overall abundance of natural enemies, parasitoids and predators. The work was carried out with yellow sticky traps from the Online Monitoring Network of Pests and Natural Enemies on Citrus established by Bayer Crop Science and the Polytechnic University of Valencia. We monitored 51 orchards, 17 per year for the three years 2014, 2015 and 2016, from all citrus-growing areas of the eastern Iberian Peninsula (Spain) and the Algarve (Southern Portugal). On each orchard, two yellow sticky traps were sampled weekly from April to September. Five families of hymenoptera parasitoids were identified: Aphelinidae was the most abundant, followed by Encyrtidae, Scelionidae, Eulophidae and Braconidae. Predators included Coccinellidae (Coleoptera), and Chrysopidae and Coniopterygidae (Neuroptera). The most abundant parasitoid in citrus orchards of the Iberian Peninsula was Aphytis spp., followed by Cales noacki and Metaphycus spp. The most abundant predators were Rodolia cardinalis and Scymnus spp. Aphelinus spp., Cales noacki and Propylea quatuordecimpunctata were mostly captured in northern areas, while Rhyzobius spp. showed major presence in southern areas. Cales noacki, Citrostichus phyllocnistoides, Rodolia cardinalis and Aphelinus spp. showed a regular seasonal pattern along the year during the three years of monitoring. We confirm the establishment of a parasitoid new for the Iberian Peninsula, Comperiella bifasciata, which appeared in most of the monitored orchards.