{"id":19146,"date":"2022-03-07T14:37:57","date_gmt":"2022-03-07T14:37:57","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/?p=19146"},"modified":"2022-08-18T11:12:22","modified_gmt":"2022-08-18T10:12:22","slug":"drosophila-suzukii-invasive-fruit-fly-investigated-scientists","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/drosophila-suzukii-invasive-fruit-fly-investigated-scientists\/19146\/","title":{"rendered":"Drosophila suzukii: an invasive fruit fly, investigated by scientists"},"content":{"rendered":"
D. suzukii<\/em>, also known as the Spotted Wing Drosophila, is a frugivorous insect native to Eastern Asia that was unintentionally introduced to the Americas and Europe in the 2,000s, where it rapidly spread and created a challenge for the classical biological control agent to tackle.<\/p>\n The fruit fly attacks approximately 150 wild and cultivated fruits, such as cherries, berries, and ornamental plants.<\/p>\n Unlike the sympatric Drosophila species in invaded areas, D. suzukii<\/em> females are able to lay eggs inside unwounded ripening fruits due to their specialised egg-laying organ, which is equipped with saw teeth, thus providing it with a unique niche virtually free from competition.<\/p>\n The resulting high abundance of D. suzukiis<\/em> led to extensive damage, and created a major problem for fruit growers, especially in the soft fruit industry.<\/p>\n Field cage releases of the parasitoid G1 Ganaspis cf. brasiliens<\/em> was conducted in two regions of Switzerland in August 2021 and supports findings from previously conducted laboratory-based experiments and the low risk for non-target impacts on native D. suzukii.<\/em><\/p>\n This collaborative study included colleagues from the Repubblica e Cantone Ticino, Agroscope, and the Institute of Agricultural Sciences (IAS) of ETH Zurich. From this research, scientists revealed that <\/span>the <\/span>larvae of the target species, <\/span><\/span>D. suzukii<\/em>,<\/span><\/span> was readily parasitised<\/span><\/span>,<\/span><\/span><\/span> and of the 957 emerging <\/span>parasitoids<\/span>, only one was from the non-target species<\/span>,<\/span> <\/span>D. melanogaster.<\/span><\/span><\/em><\/p>\n Lead researcher Dr Lukas Seehausen, based at CABI in Switzerland, explained: \u201cReleased parasitoids had the choice to parasitise either D. suzukii<\/em> larvae in fresh fruits, blueberries or elderberries, or the non-target native species D. melanogaster<\/em> in decomposing fruits, which is their natural habitat.<\/p>\n \u201cThe results were unequivocal in that parasitism of D. suzukii<\/em> larvae feeding in fresh fruits was on average 15%, whereas only one parasitoid emerged from D. melanogaster<\/em> feeding on decomposing fruits, which is a mere 0.02% parasitism.<\/p>\n \u201cThe results achieved under semi-field conditions supports findings from previous laboratory experiments that the parasitoid G1G. cf. brasiliensis<\/em> is highly specific to D. suzukii<\/em> larvae feeding in fresh fruits and parasitism of the closely related D. melanogaster<\/em> naturally feeding on decomposing fruits is very rare.<\/p>\n \u201cBecause in its invaded range D. suzukii<\/em> is the only Drosophila species that can attack and develop in undamaged fresh fruits, we conclude that possible non-target impacts are a low and acceptable risk for the control of the destructive invasive spotted wing Drosophila.\u201d<\/p>\n Scientists <\/span>noted <\/span>a recent acceptance in<\/span> the application for releases of the same <\/span>parasitoid<\/span> in the US, following <\/span>the first releases of <\/span><\/span>G. cf. <\/span>brasiliensis<\/span><\/span><\/em> in Italy in 2021. Furthermore, due to<\/span> the submission of an application in Switzerland in February 2022, further research starts to be implemented into practice.<\/span><\/span>\u00a0<\/span><\/p>\nExperiments reveal what type of species is feeding on fruits<\/h3>\n