First observations on the parasitoid complex and on the biology of Dasineura oleae during an outbreak in Tuscany, Italy

Dasineura oleae (Angelini) (Diptera Cecidomyiidae) was generally considered as a minor pest in Italy, but in 2013 an outbreak of this species was registered in the South - West of Tuscany. In the current work, we investigated several aspects of D. oleae outbreak in Tuscany: the life cycle, the pest status, variations in the infestation rate due to the first generation of 2018 and the role of parasitoids in this pest control. We observed that in 2017 D. oleae had one generation in Spring and one generation in Autumn. Our results proved that the infestation rate increased after the occurrence of D. oleae first generation of 2018 and also that D. oleae infestation rate differs across the outbreak area. Parasitism was lacking in most of the monitored sites, however where parasitization was present, a negative correlation between parasitism rate and infestation rate was evidenced. We detected three new species for Italy as parasitoids of D. oleae: Platygaster demades Walker, Platygaster oleae Szelenyi (Hymenoptera Platygastridae) and Mesopolobus aspilus (Walker) (Hymenoptera Pteromalidae).