Colonization Patterns, Phenology and Seasonal Abundance of the Nearctic Leafhopper <i>Erasmoneura vulnerata</i> (Fitch), a New Pest in European Vineyards

oleh: Carlo Duso, Giulia Zanettin, Pamela Gherardo, Giulia Pasqualotto, Damiano Raniero, Filippo Rossetto, Paola Tirello, Alberto Pozzebon

Format: Article
Diterbitkan: MDPI AG 2020-10-01

Deskripsi

The Nearctic leafhopper <i>Erasmoneura vulnerata</i> (Fitch), detected in Europe for the first time (north-eastern Italy) in 2004, has remained a minor pest of grapevine for more than 10 years. The first outbreaks of <i>E. vulnerata</i> were reported in 2016 in commercial vineyards located in north-eastern Italy. High population densities and severe leaf symptoms (i.e., leaf discoloration and fall) were observed in late summer despite the application of insecticides. Investigations were carried out from 2017 to 2019 in 10 vineyards located in Veneto region (Vicenza and Verona provinces) to shed light on the seasonal abundance of <i>E. vulnerata</i> on different <i>Vitis vinifera</i> cultivars. Pest phenology was studied in six vineyards where the impact of insecticides was minimal. <i>Erasmoneura vulnerata</i> completed three generations in each of the growing seasons. Vineyard colonization by overwintered adults showed a clear edge effect, suggesting the influence of overwintering sites (e.g., rural buildings and hedgerows) in vineyard margins. The impact of natural enemies on pest populations appeared to be limited and mostly related to egg parasitoids. Organic vineyards were more heavily infested by <i>E. vulnerata</i> compared to conventional vineyards, likely due to the minimal efficacy of natural insecticides typically used in the former farms.