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Eggmass Structure and Parasitism of Thaumetopoea wilkinsoni (Lepidoptera: Thaumetopoeidae) in Lebanon

Jenny Nasr, Efat Abou-Fakhr Hammad, Guy Demolin and Nabil Nemer

The pine processionary moth, Thaumetopoea wilkinsoni, is the most damaging pest of pine trees in Lebanon and other countries of the Mediterranean region. It spreads in Lebanon on Pinus halepensis, P. brutia and P. canariensis. The study assesses the importance of egg parasitoids of the pine processionery moth. The egg masses collected from two locations of different altitudes were placed in the environmental chamber at a constant temperature of 22 ± 2.5°C. Emergence of the parasitoids was recorded daily in the laboratory and the peak of emergence was determined for each parasitoid species. The most widely spread species in Lebanon were identified as Baryscapus servadeii and Ooencyrtus pityocampa. A significant correlation was determined between length of the egg mass and the number of eggs/egg mass for a given row number. The impact of egg parasitoids varied from 10-16%. The followup on parasitoid emergence showed different peak emergences for the two major egg parasitoids, O. pityocampae and B. servadeii and explained the coincidence between egg deposition by T. wilkinsoni and emergence of the adult parasitoids.