This paper reviews the taxonomy, distribution, basic biology, behaviour, ecology and management of exotic D. suzukii with particular emphasis to the Italian situation. D. suzukii is native to the South East Asia and was found for the first time outside its native habitat in the Hawaiian Islands in 1980, then in California and in Spain in 2008. Over the last 5 years the species has been found in many States of North America and several European countries. In Italy D. suzukii was identified for the first time in Trentino-Alto Adige in 2009, with subsequent detections Piedmont, Valle d'Aosta, Lombardy, Veneto, Emilia-Romagna, Tuscany, Liguria, Marche, Campania and recently in Sicily. The species has caused extensive damage in all Regions where it became established and has demonstrated a very rapid expansion. In the Trento Province, for instance, in 2010, the damage to small berry fruits production has been estimated in 3.000.000 €. D. suzukii is a polyphagous insect but the most damages were recorded mainly on fruits of blueberry, strawberry, raspberry, cherry, and on some varieties of grapes. In natural ecosystems D. suzukii reproduces on blackberry, elder, buckthorn, etc. Unlike other Drosophilids, D. suzukii shows the peculiar characteristic of females being able to lay their eggs inside ripening fruits, starting from veraison and preferring fruits with a thin epicarp. Females have a well-developed saw-like ovipositor, which can penetrate beneath the skin of host fruits. How males and females find each other is not yet well understood. Currently, the species has established in many European countries and North America. Control strategies adopted so far include preventive measures, the use of specific insecticides and trapping of adults. Several biocontrol agents, such as parasitoids of larvae and pupae and natural predators are under investigation. These studies could help to apply classical biological control strategies, by introducing D. suzukii natural enemies, coming from the pest’s native habitat. At present, management techniques referring to an ecological control, as the “push-pull” strategy, are not developed. Early investigations are currently focused on the possibility to reduce pest populations through the exploitation of the pest association with endosymbionts; moreover, studies aiming to investigate D. suzukii-host fruits relationships are also in progress, to identify the most attractive volatile compounds, to be used in the preparation of highly selective and attractive baits for D. suzukii.
Keywords: Drosophilidae, Diptera, Drosophila suzukii, intrusive insect, biologiacl control agents, small berry fruits, host fruits relationships, insecticides, population dynamics