Capacità di sviluppo di Diabrotica virgifera virgifera Leconte su ospiti alternativi al mais

Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) is an invasive exotic species native to Central America and introduced in Europe in the '90; in Italy if was found in 1998. In the US it is considered one of the most harmful pest of maize (Zea mais L.). In Europe it is now present in almost all the Countries where the maize is produced. Because maize is the preferred host of Diabrotica larvae, the most common control method consists in the rotation of maize with another non-host crop. The aim of this work was the study of the potential role of the alternative host plants in our habitat, with particular attention to other Poaceae and weeds. Species were selected among those never tested before or on which the results were disaccording between Authors. Tests with artificial infestation in glasshouse and with natural infestation in fields were conducted and survival, development and performance of Diabrotica were evaluated. Studies confirmed the capability of Diabrotica to survive on numerous Poaceae, with preference for cereals. Larvae of different stages and pupae were observed on different plant species, both with artificial and natural infestation. However, the development of Diabrotica on the alternative host plants was slower than on maize and preimmaginal stages showed lower values of morphometric characteristics than on maize. Adults from different hosts were captured only with artificial infestation, never in natural condition. Most interesting species as alternative host for Diabrotica are cereals (Triticum spelta and Panicum miliaceum) and the weed Sorghum halepense, very common in maize fields. We can hypothesize that these species could be used from Diabrotica in the absence of maize, reducing the efficiency of the crop rotation as eradication or control method.