Biologia e ecologia degli ortotteri tipici degli ecosistemi naturali e agrari: dalla gestione delle infestazioni alla conservazione della biodiversità

Orthopterans occur in most terrestrial habitats and their order includes the grasshoppers, locusts, crickets, and their relatives. They could have an ecological and economic importance, as pivotal elements in trophic food webs and as pests, causing devastating damages to agricultural and forest crops. There are two different management responses: reducing population levels in pest management and maintaining or increasing population levels in conservation management. While the phenomenon of outbreak in Orthoptera is well known worldwide especially for Caelifera suborder, less studied are the outbreaks of Ensifera. The recent and unexpected outbreaks of the bush-cricket Barbitistes vicetinus in the north-east of Italy, gave me the possibility to unravel some significant questions about this forest pest. Firstly, we confirmed the endemic origin of this species, suggesting that environmental factors rather than genetic factors could have a role in the demographic fluctuations of this orthopteran. Secondly, we clarified the role of temperature on survival and diapause, demonstrating how summer temperatures experienced by eggs after oviposition can affect their development, potentially shifting life-cycle from pluriannual to annual. Morevoer, we discovered a native egg parasitoid providing biological, taxonomical and distributional data that could be useful regarding its potential use in biological control against B. vicetinus. Another goal of this thesis was to implement conservation strategies to preserve different Orthoptera species with different ecological requirements. In particular, because agricultural intensification is widely considered a major threat to biodiversity, we investigated wether extensively managed perennial crops such as vineyards and olive groves could represent surrogate habitats for orthopterans. In addition, we focused on the endangered bush-cricket Anonconotus italoaustriacus, analysing genetic populations diversity among its small distribution area in the Alps to improve conservation strategies and prevent extinction.Orthopterans occur in most terrestrial habitats and their order includes the grasshoppers, locusts, crickets, and their relatives. They could have an ecological and economic importance, as pivotal elements in trophic food webs and as pests, causing devastating damages to agricultural and forest crops. There are two different management responses: reducing population levels in pest management and maintaining or increasing population levels in conservation management. While the phenomenon of outbreak in Orthoptera is well known worldwide especially for Caelifera suborder, less studied are the outbreaks of Ensifera. The recent and unexpected outbreaks of the bush-cricket Barbitistes vicetinus in the north-east of Italy, gave me the possibility to unravel some significant questions about this forest pest. Firstly, we confirmed the endemic origin of this species, suggesting that environmental factors rather than genetic factors could have a role in the demographic fluctuations of this orthopteran. Secondly, we clarified the role of temperature on survival and diapause, demonstrating how summer temperatures experienced by eggs after oviposition can affect their development, potentially shifting life-cycle from pluriannual to annual. Morevoer, we discovered a native egg parasitoid providing biological, taxonomical and distributional data that could be useful regarding its potential use in biological control against B. vicetinus. Another goal of this thesis was to implement conservation strategies to preserve different Orthoptera species with different ecological requirements. In particular, because agricultural intensification is widely considered a major threat to biodiversity, we investigated wether extensively managed perennial crops such as vineyards and olive groves could represent surrogate habitats for orthopterans. In addition, we focused on the endangered bush-cricket Anonconotus italoaustriacus, analysing genetic populations diversity among its small distribution area in the Alps to improve conservation strategies and prevent extinction