Watanabe, M.A., Tambasco, F.J, Nardo, E.A.B., Viana, R.I., & Pereira, G.D. 2000 [Competition between Selenaspidus articulatus and Parlatoria ziziphi scales in orchards in the Citrus region of Sao Paulo State.]. Laranja 21(1) 81-97.

Notes: [Original title: Competiçao entre as cochonilhas Selenaspidus articulatus e Parlatoria ziziphi em pomares da regiao citricola paulista.] A study was carried out in 1996 in 26 Citrus orchards to investigate if rufous scale (Selenaspidus articulatus) and black scale (Parlatoria ziziphi) scales competed for the ecological niche represented by Citrus leaves. Possible relationships between occurrence and climatic factors were also investigated. S. articulatus was the dominant species during most of the year. P. ziziphi was less affected by climatic factors, whereas high temperature and humidity were more favourable to S. articulatus.