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Prazaru SC, dal Mas G, Padoin M, Rizzardo D, Meggio F, Pitacco A, Pozzebon A, Duso C. Effect of Leaf Removal and Insecticide Applications on Population Densities of Leafhoppers and Mites Associated with Grapevines. INSECTS 2023; 14:791. [PMID: 37887803 PMCID: PMC10607907 DOI: 10.3390/insects14100791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/28/2023]
Abstract
In this study, we tested the effects of mechanical leaf removal, insecticide application, and their interaction on leafhoppers and phytophagous and predatory mites occurring in two vineyards over three growing seasons. Leaf removal was performed in the fruit zone using a two-head pulsed air leaf remover, while insecticides were applied with a tunnel air-assisted sprayer at the maximum dose/ha recommended on the product label. Results demonstrated the efficacy of insecticide application in reducing the population densities of leafhoppers but also their detrimental effects on predatory mites. In a number of case studies, leaf removal reduced leafhopper and predatory mite densities. In one vineyard, phytophagous mite populations increased some weeks after leaf removal and insecticide application, highlighting the need to carefully consider the potential impact of vineyard management practices on non-target arthropods in the IPM framework.
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Affiliation(s)
- Stefan Cristian Prazaru
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
| | - Giovanni dal Mas
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
| | - Matteo Padoin
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
| | - Denis Rizzardo
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
| | - Franco Meggio
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
- Centre for Research in Viticulture and Enology (CIRVE), Viale XXVIII Aprile 14, 31015 Conegliano, Italy
| | - Andrea Pitacco
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
- Centre for Research in Viticulture and Enology (CIRVE), Viale XXVIII Aprile 14, 31015 Conegliano, Italy
| | - Alberto Pozzebon
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
- Centre for Research in Viticulture and Enology (CIRVE), Viale XXVIII Aprile 14, 31015 Conegliano, Italy
| | - Carlo Duso
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padua, 35020 Legnaro, Italy; (G.d.M.); (M.P.); (D.R.); (F.M.); (A.P.); (A.P.); (C.D.)
- Centre for Research in Viticulture and Enology (CIRVE), Viale XXVIII Aprile 14, 31015 Conegliano, Italy
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Evaluating the Impact of Two Generalist Predators on the Leafhopper Erasmoneura vulnerata Population Density. INSECTS 2021; 12:insects12040321. [PMID: 33917285 PMCID: PMC8067415 DOI: 10.3390/insects12040321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/26/2021] [Accepted: 04/02/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Erasmoneura vulnerata, a grapevine leafhopper native to North America, was detected in Europe (North-eastern Italy) in the early 2000s. Although it is considered a minor pest in its native range, outbreaks of this species have been reported in North-eastern Italy. In this study, we investigated the potential of two generalist predators, i.e., Chrysoperla carnea and Oriusmajusculus, in suppressing E. vulnerata in laboratory and semi-field experiments. Both species significantly reduced nymph numbers in laboratory and semi-field conditions. For this reason, field trials were performed. Predator releases in vineyards reduced E. vulnerata abundance by about 30%. Since naturally occurring E. vulnerata antagonists exert a moderate impact and the effectiveness of natural insecticides is limited, the augmentative release of generalist predators can be considered a complementary tool in controlling E. vulnerata populations in vineyards, particularly in organic farms. Abstract Outbreaks of the Nearctic leafhopper Erasmoneura vulnerata represent a threat to vinegrowers in Southern Europe, in particular in North-eastern Italy. The pest outbreaks are frequent in organic vineyards because insecticides labeled for organic viticulture show limited effectiveness towards leafhoppers. On the other hand, the naturally occurring predators and parasitoids of E. vulnerata in vineyards are often not able to keep leafhopper densities at acceptable levels for vine-growers. In this study, we evaluated the potential of two generalist, commercially available predators, Chrysoperla carnea and Orius majusculus, in suppressing E. vulnerata. Laboratory and semi-field experiments were carried out to evaluate both species’ predation capacity on E. vulnerata nymphs. The experiments were conducted on grapevine leaves inside Petri dishes (laboratory) and on potted and caged grapevines (semi-field); in both experiments, the leaves or potted plants were infested with E. vulnerata nymphs prior to predator releases. Both predator species exhibited a remarkable voracity and significantly reduced leafhopper densities in laboratory and semi-field experiments. Therefore, field studies were carried out over two growing seasons in two vineyards. We released 4 O. majusculus adults and 30 C. carnea larvae per m2 of canopy. Predator releases in vineyards reduced leafhopper densities by about 30% compared to the control plots. Results obtained in this study showed that the two predators have a potential to suppress the pest density, but more research is required to define appropriate predator–prey release ratios and release timing. Studies on intraguild interactions and competition with naturally occurring predators are also suggested.
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Tirello P, Marchesini E, Gherardo P, Raniero D, Rossetto F, Pozzebon A, Duso C. The Control of the American Leafhopper Erasmoneura vulnerata (Fitch) in European Vineyards: Impact of Synthetic and Natural Insecticides. INSECTS 2021; 12:insects12020085. [PMID: 33498174 PMCID: PMC7908998 DOI: 10.3390/insects12020085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022]
Abstract
The American leafhopper Erasmoneura vulnerata, detected in Europe in the early 2000s, has recently become a pest in North-Italian vineyards. Infestations were recorded in organic and conventional vineyards despite the application of insecticides targeting other pests. Erasmoneura vulnerata completes three generations per year, and the second generation is frequently associated with large populations. The selection of appropriate active ingredients and the timing of their application is crucial for effective pest control. Field trials were carried out in Northeastern Italy, using a randomized design, to evaluate the impact of insecticides applied against other grapevine leafhoppers on E. vulnerata populations. The beginning of the second generation was selected as the best time for insecticide application. For natural products, two applications were planned. Among the selected insecticides, the most effective were acetamiprid, flupyradifurone and lambda-cyhalothrin. Regarding natural products, the most effective was kaolin which could represent an alternative to pyrethrins in organic vineyards. The identification of pest threshold levels and the evaluation of side effects of the most effective insecticides on key natural enemies occurring in vineyards are required.
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Affiliation(s)
- Paola Tirello
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, Agripolis, Legnaro, 35020 Padova, Italy; (P.T.); (P.G.); (D.R.); (F.R.); (A.P.)
| | - Enrico Marchesini
- AGREA S.r.l. Centro Studi, Via Garibaldi 5/16, San Giovanni Lupatoto (VR), 37057 Verona, Italy;
| | - Pamela Gherardo
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, Agripolis, Legnaro, 35020 Padova, Italy; (P.T.); (P.G.); (D.R.); (F.R.); (A.P.)
| | - Damiano Raniero
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, Agripolis, Legnaro, 35020 Padova, Italy; (P.T.); (P.G.); (D.R.); (F.R.); (A.P.)
| | - Filippo Rossetto
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, Agripolis, Legnaro, 35020 Padova, Italy; (P.T.); (P.G.); (D.R.); (F.R.); (A.P.)
| | - Alberto Pozzebon
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, Agripolis, Legnaro, 35020 Padova, Italy; (P.T.); (P.G.); (D.R.); (F.R.); (A.P.)
| | - Carlo Duso
- Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell’Università 16, Agripolis, Legnaro, 35020 Padova, Italy; (P.T.); (P.G.); (D.R.); (F.R.); (A.P.)
- Correspondence: ; Tel.: +39-049-8272805
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Duso C, Zanettin G, Gherardo P, Pasqualotto G, Raniero D, Rossetto F, Tirello P, Pozzebon A. Colonization Patterns, Phenology and Seasonal Abundance of the Nearctic Leafhopper Erasmoneura vulnerata (Fitch), a New Pest in European Vineyards. INSECTS 2020; 11:insects11110731. [PMID: 33114643 PMCID: PMC7692148 DOI: 10.3390/insects11110731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/02/2020] [Accepted: 10/23/2020] [Indexed: 12/02/2022]
Abstract
Simple Summary The leafhopper Erasmoneura vulnerata (Fitch) (Hemiptera: Cicadellidae) is native to North America, and was found in Europe for the first time (north-eastern Italy) in 2004 where it remained a minor pest of grapevine for more than ten years. Recently, its importance increased in commercial vineyards located in north-eastern Italy, where outbreaks of E. vulnerata populations with severe leaf symptoms were observed despite insecticide applications. Information on its biology and ecology is needed for the development of management strategies. Here, we investigated the phenology and seasonal abundance of E. vulnerata in commercial vineyards. We found that E. vulnerata can complete three generations per growing season. Vineyard colonization by overwintered adults showed a clear edge effect, suggesting an effect of overwintering sites (e.g., rural buildings and hedgerows) adjacent to vineyards. 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 E. vulnerata compared to conventional vineyards, likely due to the low effectiveness of natural insecticides typically used in the former farms. The results generated by this study provide implications for the management of this pest in European vineyards. Abstract The Nearctic leafhopper Erasmoneura vulnerata (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 E. vulnerata 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 E. vulnerata on different Vitis vinifera cultivars. Pest phenology was studied in six vineyards where the impact of insecticides was minimal. Erasmoneura vulnerata 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 E. vulnerata compared to conventional vineyards, likely due to the minimal efficacy of natural insecticides typically used in the former farms.
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