Whiteflies and natural enemies on orange crops under two types of sanitary management in San Pedro, Buenos Aires province

Whiteflies (Hemiptera: Aleyrodidae) are important pests that affect the genus  Citrus . The objective of this study was to identify the species present in orange orchards in San Pedro (province of Buenos Aires) and to analyze their population evolution and that of their natural enemies under two sanitary management (conventional and organic). The density of adults, parasitized and non-parasitized nymphs, species and density of predators and parasitoids, presence of sooty mold on leaf/fruit, fruit yield and applied agrochemicals were recorded monthly. The prevalent species of whiteflies were Dialeurodes citri (Ashmead) and  Singhiella citrifolii (Morgan), whose adult populations developed between October and May, without differences between types of management. The nymphs were present throughout the year, with higher density in organic crops. Sooty mold levels were similar for both managements. The predator Euseius concordis (Chant) (Acari: Phytoseiidae) was the most abundant natural enemy, with higher density in organic crops compared to conventional ones. There were low levels of parasitism by Encarsia protransvena  Viggiani, Encarsia group  strenua (Hymenoptera: Aphelinidae) and  Neopomphale sp. (Hymenoptera: Eulophidae). The fruit field was higher in the conventional treatment. Results show the need of controlling the pest with less harmful products for the beneficial fauna.