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    Use of yellow sticky traps to study daily flight activity and behaviour of sap-sucking insects inhabiting European vineyards

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    Yellow sticky traps are used to monitor sap-sucking insects in their roles as both pests and vectors across a broad range of crops including vineyards. They are also used to understand different aspects of insect biology, and for this purpose, a number of studies have been conducted to determine the daily flight activity of leafhoppers and thrips. In a vineyard in north-eastern Italy, the daily flight activities of leafhoppers [e.g. Empoasca vitis (Gothe), Zygina rhamni Ferrari, Scaphoideus titanus Ball], as well as the vine thrips Drepanothrips reuteri Uzel, were studied with yellow sticky traps during different monitoring days of the growing season. The traps were placed in both shady and sunny positions with respect to the grapevine foliage, and in inter-rows. They were routinely replaced every hour from the start of dawn to the end of dusk, while during the hours of darkness there was no replacement, except on one monitoring day. E. vitis, S. titanus and D. reuteri were mainly captured in sunny positions, while Z. rhamni was captured in shady positions. E. vitis exhibits bimodal daily flight activity with two peaks respectively at the dawn-sunrise and sunset-dusk. Z. rhamni prefers to fly around sunrise, when daily temperatures are lower, and S. titanus flies continuously from sunset to sunrise. The vine thrips flies only during sunshine hours. The daily hours with higher flight activity are mostly associated with changes in light intensity. The moderate light intensity that occurs immediately after sunrise and just before sunset inhibits the flight activity of leafhoppers outside the canopy but not inside. Knowing the daily flying activity and behaviour of leafhoppers and thrips can have important implications for establishing the optimal sampling time because in the hours of the highest flying activity counting adults can be more difficult

    Standardization and criticism of sampling procedures using sticky card traps: Monitoring sap-sucking insect pests and anagrus atomus inhabiting european vineyards

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    Coloured sticky card traps are widely used for sampling and control of sap-sucking insect pests. In European vineyards they are used for monitoring leafhoppers [i.e., Empoasca vitis (Gothe), Zygina rhamni Ferrari, Scaphoideus titanus Ball], the vine thrips Drepanothrips reuteri Uzel and the leafhopper egg parasitoid Anagrus atomus (L.). A study was conducted to establish the trap factors that influence captures of these insects (i.e., size, inclination, exposure days, colour, position within canopy and side orien-tation). The total captures of grapevine leafhoppers increased as trap size increased, without a significant decline in captures relative to unit area. All leafhopper species were more attracted by vertical traps than horizontal traps, and in the latter case, E. vitis and Z. rhamni were mainly captured on the underside of the trap, while S. titanus on the upper side. For all leafhoppers and D. reuteri, efficiency decreased with the number of days the traps remained in the field. Yellow was a colour preferred by all in-sects, with Z. rhamni showing a strong preference for lighter yellows. S. titanus was also captured by red traps and A. atomus by colourless ones. Z. rhamni and S. titanus showed a preference for traps placed in shady positions, whereas E. vitis and D. reuteri preferred traps in sunny positions. E. vitis and D. reuteri preferred trap sides exposed to sunlight in the late afternoon and early morning, respectively. Our results were compared with the literature and discussed in relation to the feeding preference and behaviour of the different species

    Side Effects of Kaolin and Bunch-Zone Leaf Removal on Generalist Predators in Vineyards

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    In vineyards, kaolin application and bunch-zone leaf removal (LR) were effective in the control of leafhoppers and Lobesia botrana, but their side effects on generalist predators are still poorly understood. In north-eastern Italian vineyards, the impact of kaolin and LR on species and functional diversity of spiders, as well as the abundance of spiders and generalist predatory insects, was assessed in one vineyard for two consecutive years and in two vineyards for one year. The ecological indices of the spider community were never influenced by kaolin and only in one case were they influenced by LR. At the spider family level, kaolin reduced the abundance of Araneidae, Oxypidae and Salticidae, but only in single cases. In single cases, kaolin reduced the amount of Orius sp. anthocorids and increased that of Scymninae coccinellids, whereas LR increased the amount of Aeolothrips sp. The moderate use of kaolin and the application of LR had negligible and inconsistent impacts on generalist predatory arthropods in vineyards and were therefore, compatible with IPM strategies

    Is the Removal of Nettles along Ditches Effective in Controlling Bois Noir in Vineyards?

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    Bois noir (BN) is a grapevine yellows disease associated with ‘Candidatus Phytoplasma (Ca. P.) solani’ that is transmitted to grapevines by the planthopper Hyalesthes obsoletus Signoret which uses herbaceous plants such as Urtica dioica as a pathogen reservoir. Urtica dioica is often widespread along ditches bordering vineyards, and a gradient in decreasing BN symptomatic grapevines is observed from the vineyard edges facing these ditches. In two vineyards in north-eastern Italy, over eight or seven years, the ditch bordering one edge of each vineyard was divided into two sections; in one of these, U. dioica was chemically weeded in April, while the other one remained untreated. The impact of chemical weeding on the spatial distribution of both H. obsoletus captures and newly BN symptomatic grapevines was assessed. The reduction in H. obsoletus captures in the vineyard sector facing the section of the ditch subjected to weeding corresponded to a decrease in newly symptomatic grapevines. These findings demonstrated that nettle removal from areas surrounding vineyards can effectively control BN

    Side effects of sulfur dust on the European grapevine moth Lobesia botrana and the predatory mite Kampimodromus aberrans in vineyards

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    To reduce the impact of synthetic insecticides on human health and the environment, eco-friendly alternatives must be investigated. Knowledge of the side effects on pests and natural enemies of natural products applied to vineyards is very useful. Sulfur dust, which is used in vineyards to control powdery mildew, is investigated in laboratory and field bioassays for its effects on Lobesia botrana egg laying, egg hatching, and larval settlement. In field trials, the efficacy of sulfur dust against the two L. botrana carpophagous generations is compared with that of Bacillus thuringiensis and kaolin, and its side effects on the phytoseiid mite Kampimodromus aberrans are evaluated. In the bioassays, sulfur dust reduced female survival by 43%, egg laying by around 80%, egg hatching by 10%, and larval settlement by 55%. In field trials, sulfur dust caused a significant decrease in the number of L. botrana larval nests of both generations, even though the efficacy was lower than that of B. thuringiensis. No negative effects of sulfur dust on the predatory mite population density was observed. On the basis of these results, in the context of Integrated Pest Management strategies in vineyards, the activity of sulfur dust against L. botrana could be exploited by timing its application to the beginning of egg laying

    Relationships between hyalesthes obsoletus, its herbaceous hosts and bois noir epidemiology in northern italian vineyards

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    Hyalesthes obsoletus is the vector of “Candidatus Phytoplasma (Ca. P.) solani,” the causal agent of grapevine yellows Bois noir (BN). The relationships among the planthopper, its main herbaceous hosts as phytoplasma reservoirs (Convolvolus arvensis and Urtica dioica) and BN spreading were studied in northern Italy. In two areas the relationship between host plants and the phenology and survival of planthopper adults was investigated in potted plants and in field conditions. Moreover, H. obsoletus ecology, newly symptomatic grapevine occurrence and “Ca. P. solani” tuf-types’ presence were studied in two vineyards (2014–2019). An earlier occurrence of H. obsoletus adults on C. arvensis than U. dioica and better adult survival of the originating host were observed. When U. dioica was prevalent, the vector occurred almost exclusively along the ditch outside the vineyard. Hyalesthes obsoletus amount varied widely from year to year and nymphal mortality due to late frosts was supposed. In one vineyard, the amount of newly symptomatic grapevines was significantly correlated with vector abundance in the previous year. The “Ca. P. solani” tuf-type was influenced by vector population levels on the two hosts. Since the abundance of H. obsoletus populations on the two hosts influences BN epidemiology and dynamics and the “Ca. P. solani” tuf-type, this must be considered in BN control strategies

    Danni da Carpophilus lugubris in fragoleti del Nord Italia

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    Damage caused by the dusky sap beetle, Carpophilus lugubris, in strawberry fields in North-eastern Italy The small beetle Carpophilus lugubris Murray (Coleoptera: Nitidulidae) has caused infestations in some strawberry fi elds of North-eastern Italy since 2013. This pest is an alien species of American origin, known as «dusky sap beetle» in the Usaand «carpofilo americano» in Italy. The most serious damage was observed in strawberries fields close to the harvest, especially in 2015 in the Verona district. The control of this pest with the use of insecticides is particularly difficult, due to the absence of authorized products against this species and the need to respect the pre-harvest intervals
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