none. Observations carried out during 1990-92 on Apulia Region (Southern-Italy) using "trap-tests" baited with the sex pheromone of Thaumetopoea pityocampa (Den. et Schiff.) made possible to assure differences in the flight period of males in pine woods at different altitudes. Moreover, it does not seem to exist a relationship between captured males and patterns of the infestations while there is a connection between the number of overwintering larvae and pine-trees defoliations more than between the number of winter nests and defoliations; in fact the average number of larvae within the winter nests was more than 100 in the pine woods heavy infested by T. pityocampa and about 46 larvae where the pine-trees were light infested even if the winter nests were numerous. During the period of the researches the following natural enemies complex was found: - from the eggs: Ooencyrtus pityocampae (Merc.) (Encyrtidae), Eutetrastichus servadeii (Dom.) (Eulophidae), Anastatus bifasciatus B. de fonsc. (Eupelmidae), Eupelmus urozonus Dalm. (Eupelmidae), and Macroneura (=Eupelmella Masi) sp. (Eupelmidae), Trichogramma embryopagum (Htg.) (Trichogrammatidae); - from the larvae: Phryxe caudata Rondani (Diptera: Tachinidae); - from the eopupae: Hexamermis sp. (Nematoda: Mermithidae), which was for the first time found in pine processionary; - from the pupae: Coelichneumon rudis B. de Fonsc. (Hymenoptera: Ichneumonidae), Conomorium pityocampae Graham (Hymenoptera: Pteromalidae), P. caudata, and Villa sp. (Diptera: Bombyliidae). Larvae and pupae were also parasitized by Beauveria bassiana (Vuill.) Balsam. and Paecilomyces farinosus (Dicks.) (Deuteromycotina: Hyphomycetes). While the parasitoids of larvae and pupae had low importance, the incidence of egg-parasitoids were high; in particular O. pityocampae and E. servadeii were the most active. Interesting was the action of the magpies (Pica pica L.) where pieces of T. pityocampa adults and eggs were found in their stomachs.