Toxicity of essential oils extracted from Origanum onites L. and Citrus aurentium L. against the pine processionary moth, Thaumetopoea wilkinsoni Tams.

The pine processionary moth (PPM), Thaumetopoea wilkinsoni Tams. (Lepidoptera: Thaumetopoeidae), is an important forest pest in the Mediterranean area, additionally urticating hairs of the caterpillars of this species cause strong allergic reactions on skin of humans and animals. In the present study, essential oils extracted from aerial parts of Origanum onites L. and fruit peels of Citrus aurentium L. were tested at three doses (0.1, 0.5 and 1%) against 4th and 5th instar larvae of the pest. The results showed that the activities were concentration dependent. The LD50 and LD90 values were 0.288 and 0.926% for O. onites, 0.530 and 2.306% for C. aurentium, respectively.