Mineral and Plant Oils as Management Tools to Control Insect Vectors of Phytoplasmas

Phytoplasmas are small unculturable and wall-less prokaryotes that are transmitted by phloem-feeder insects. Depending on the economic value of the plants they infect and/or the lifespan of the infected plants, phytoplasma infection can have devastating economic impacts in term of fruit/seed production and quality. To date, there is no commercially available methods to control phytoplasma in plants or insects. Phytoplasma disease management is frequently achieved by spraying insecticides to control the insect vector population. However, this method is not environmentally friendly and have several shortcomings such as favoring insect resistance. Plant and mineral oils have been used to control insect pests for many decades, whether as solvent, adhesives or because of their direct insecticidal properties. This chapter reviews elements relevant to direct or indirect management of insect vectors of phytoplasmas using mineral or plant oils, focusing on oil structure, composition and properties as well as mode of actions. Factors influencing their efficacy as insectides is also discussed.