Can exotic drosophilids share the same niche of the invasive Drosophila suzukii?

The presence of the four exotic drosophilids Chymomyza amoena (Loew), Drosophila suzukii (Matsumura), Zaprionus indianus (Gupta) and Zaprionus tuberculatus Malloch has been investigated in different orchards in Northern Italy for two consecutive years. The presence and the abundance of the population of the drosophilid flies were surveyed with apple cider vinegar traps, fruit baited traps, and fruit collection. Chymomyza amoena, Z. tuberculatus and D. suzukii have been identified in the Apple Cider Vinegar traps in both years. Only D. suzukii and Z. tuberculatus emerged from fruit baited traps. Except for D. suzukii, no other exotic drosofilid was captured from the fruit collection. Z. indianus was never observed. Analyses of the presence of the different species, seasonal occurrence and sex ratio are provided.