Bioactivity of Essential Oils and Respective Volatile Monoterpenoids against Thaumetopoea pityocampa and T. wilkinsoni

Abstract

The pine processionary moth (PPM) is a dangerous parasitic insect pest of several pine species in the Mediterranean basin, causing defoliation and promoting tree decline. Larvae release urticating hairs that cause strong allergic reactions in humans and animals. Pest management practices implemented by national health authorities include the eradication of nests and application of chemical insecticides. However, commercial pesticides can induce PPM resistance and be harmful to the environment and human health. Essential oils (EOs) are environmentally friendlier alternatives to commercial insecticides. The present review analyses the existing body of work on the biological activity against the PPM and highlights the most successful EOs. A total of nine publications were identified, reporting on the biological activity of 38 EOs extracted from 31 plant species against the PPM. The EOs extracted from Achillea arabica, Citrus aurantium, Lavandula angustifolia, Origanum onites and Thymus vulgaris showed the lowest half maximal lethal concentrations (LC50). O. onites EO components with the highest activities were the monoterpenoid isomers carvacrol and thymol. The use of EOs is a potential ecofriendly alternative for successful PPM pest management, however more extensive studies must be performed to pinpoint highly active and easily accessible EOs and respective volatiles.