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Use of yellow sticky traps to study daily flight activity and behaviour of sap-sucking insects inhabiting European vineyards
No full textYellow 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
A Multi-Year Study on the Presence and Infestation Levels of Cameraria ohridella and Guignardia aesculi on Horse Chestnut in North-Eastern Italy
Full text linkThe alien leaf miner Cameraria ohridella (Lepidoptera, Gracillariidae) is damaging horse chestnuts in European countries. Since native natural enemies cannot control the moth, integrated control strategies must be implemented. In north-eastern Italy, from 1997 to 2020, sampling was performed on 55 sites to record the presence of and estimate the leaf damage caused by C. ohridella and the fungus Guignardia aesculi. The level of leaf removal from the ground in autumn was estimated, and information on altitude (199–1294 m a.s.l.), average annual temperature (4.4–11.9 °C) and rainfall (954–1394 mm), and the occurrence of trunk injection with abamectin was collected. Damage caused by the leaf miner and the fungus declined with decreasing temperatures, with negligible damage at sites with average annual temperatures below 7 °C (above 1000 m a.s.l. in the study area). Since, in the study sites, complete leaf removal provided comparable efficacy to trunk injections with abamectin, we suggest adopting this environmentally friendly practice to maintain C. ohridella below damaging levels. Interspecific competition occurred between C. ohridella and G. aesculi because leaf damage from one competitor decreased as damage from the other increased
Gravi deperimenti del noce comune in giovani impianti da legno in Friuli-Venezia Giulia.
No full textStandardization and criticism of sampling procedures using sticky card traps: Monitoring sap-sucking insect pests and anagrus atomus inhabiting european vineyards
No full textColoured 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
Full text linkIn 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
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