The effect of some commercial plant oils on the pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae)

Abstract

Thaumetopoea pityocampa (Lepidoptera: Notodontidae) is one of the major forest pests and causes serious damage especially to pine trees. Mechanical and chemical methods are used in the control of this pest in Turkey's forests. In recent years, a chemical control has been the most preferred method against this pest. Due to the chemical control's harmful effects on the environment and the human health, alternative methods of control are being emphasised today. There are many studies on the use of plant oils against pests in agricultural areas. However, studies on the effect of plant oils against the pine processionary larvae are very limited. In this study, commercial oils containing 8 different essential oil types (thyme oil, peppermint oil, poppy oil, garlic oil, rosemary oil, pine oil, sage oil, lavender oil) were applied in 3 different doses (0.1%, 0.5%, 1%) and 4 repetitions against the pine processionary larvae. The experiments were conducted at 65% humidity and 25 degrees C in laboratory conditions. The study was monitored for five days and the results were evaluated through the mortality rates. On the 5th day of the study, 1% dose of thyme oil was found to be most effective with 100% mortality followed by the poppy oil (95%), the sage oil (95%), the garlic oil (90%), the rosemary oil (70%), and the pine oil (45%). The peppermint (40%) and lavender oil used in the study were found to be ineffective. As a result of the study, it was determined that thyme oil, poppy oil, sage oil, and garlic oil were effective against the pine processionary larvae and that they had the potential to be used in the control of this pest.