Tumminelli, R., Conti, F., Maltese, U., Pedrotti, C.C., & Colazza, S. 2003 Petroleum-derived spray oils: current status in the Italian citrus IPM.. Bulletin OILB/SROP 26(6): 175-183.

Notes: [Integrated control in citrus fruit crops. Proceedings of the IOBC/WPRS Working Group, Valencia, Spain, 6-8 November, 2002. Garcia-Marí, F. (Ed.) Publisher: International Organization for Biological and Integrated Control of Noxious Animals and Plants (OIBC/OILB), West Palaearctic Regional Section (WPRS/SROP).] This paper reviews the specification of petroleum spray oil (PSO) products used in Italian citriculture since the 1940s and introduces a three-level, hierarchical new classification scheme related to the degree of refinement of PSOs used in agriculture for pest control: mineral oils (MOs), agricultural mineral oils (AMOs) and horticultural mineral oils (HMOs). In 1995/2001, six commercial PSOs of varying specifications were applied to citrus groves to determine the impact to natural enemies, efficacy and influence on fruit production. In 1994/2000 IPM demonstration programme, summer applications of PSOs decreased the pressure of California red scale Aonidiella aurantii on citrus grove. In experimental fields in 1995, the parasitization of California red scale by Aphytis melinus was not affected by PSOs, but the parasitization of woolly whitefly (Aleurothrixus floccosus) by Cales noacki was affected. In 2000/01 spraying seasons, summer application of heavier PSOs reduced the crop yield and increased the fruit size compared with lighter oil. Most growers were familiar with the winter application, as they saw only the negative consequences of summer PSOs (leaf drop, sunburn and yield reduction). In summer applications, the new generation PSOs were safer. These recommendations are included in the IPM programmes funded by the European Union.