Author(s): Essaidi, Khaled Bouzar ; Branco, Manuela ; Battisti, Andrea ; Garcia, André ; Fernandes, Maria Rosário ; Chabane, Younes ; Bouzemarene, Mourad ; Benfekih, Leila
Date: 2022
Persistent ID: http://hdl.handle.net/10400.5/23035
Origin: Repositório da Universidade de Lisboa
Subject(s): egg parasitism; Thaumetopoea pityocampa; density-dependent response; land-use; specialist parasitoid; generalist parasitoid; climate
Thaumetopoea pityocampa is the most important pine defoliator in the Mediterranean 24 basin. Despite being attacked by a number of natural enemies, populations occur 25 frequently at high density in several areas. 26 2 Egg parasitism was studied in 27 pine and cedar forests in Algeria, in relation to the host 27 density (tents per tree) and the proportion of forest cover in the landscape. 28 3 Egg parasitism varied from 2 to 25%, accounted by two parasitoid species the specialist 29 Baryscapus servadeii and the generalist Ooencyrtus pityocampae. 30 4 Tent density was negatively correlated with parasitism by B. servadeii but not with that of 31 O. pityocampae. Conversely, parasitism by O. pityocampae increased with the proportion 32 of forest and agricultural cover, but not that of B. servadeii. 33 5 Maximum summer temperature showed no correlation with parasitism rates. Still, 34 temperature frequently exceeded 40ºC during the period of adult parasitoid activity. 35 6 The low performance of the egg parasitoids at the southern edge of the host range could 36 be explained by the reduced fecundity of the host, climate effects, and phenological 37 mismatching between the parasitoids and the egg development. These and other factors 38 potentially involved need to be further explored with a long-term study of population 39 dynamics.
