Drosophila suzukii (Matsumura), commonly known as Spotted Wing Drosophila (SWD), is a worldwide serious economic threat to the production of berries and stone fruits. The chemical control widely used against this pest is often not able to preventing yield losses because wild flora offers an abundance of fruits to D. suzukii where the pest is able to reproduce and from where it recolonizes neighbouring cultivated fields. Alternatively, within Integrated Pest Management protocols for D. suzukii, biological control could play a key role by reducing its populations particularly in non-cultivated habitats, thus increasing the effectiveness and reducing the side negative effects of other management strategies. Because of the scarcity and of the low efficiency of autochthonous parasitoids in the new invaded territories, in the last few years, a number of surveys started in the native area of D. suzukii to find parasitoid species to be evaluated in quarantine structures and eventually released in the field, following a classical biological control approach. This paper reports the results of these surveys carried out in South Korea and for the first time in China. Among the parasitoids collected, those belonging to the genus Asobara Foerster resulted dominant both by number and species diversity. By combining morphological characters and the mitochondrial COI gene as a molecular marker, we identified seven species of Asobara, of which two associated with D. suzukii, namely A. japonica and A leveri, and five new to science, namely Asobara brevicauda, A. elongata, A mesocauda, A unicolorata, A. triangulata. Our findings offer new opportunity to find effective parasitoids to be introduced in classical biological control programmes in the territories recently invaded by D. suzukii.

Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), commonly known as the tomato borer, is native to South America and has rapidly spread in various European countries becoming one of the major threats of tomato crop. The parasitic wasp Trichogramma achaeae Nagaraja and Nagarkatti (Hymenoptera: Trichogrammatidae) has been suggested as a possible biological control agent of the invasive pest and several aspects of its taxonomy have been elucidated. As for other egg parasitoids, the parasitism rate of this species is influenced by the rearing host and by the biotic environment, especially temperature. Starting from commercially available material, we assessed the influence of different rearing host eggs on T. achaeae longevity and fertility. We found that a single generation of the parasitoid on Tuta absoluta eggs laid on tomato leaf significantly improved T. achaeae attack rate against the tomato borer.Moreover, we found a positive effect between temperatures during development (acclimation) and the fertility of the parasitoid at different temperatures. This was particularly evident at 15°C which was optimal for parasitoid fertility at low temperatures. We conclude that the combination of rearing system (plant ? host egg) and temperatures (during development and use) are crucial factors for optimizing efficiency in terms of longevity and fertility of this species as a biocontrol agent of the tomato borer.

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