Two-Phase Stefan Problem as the Limit Case of Two-Phase Stefan Problem with Kinetic Condition

AbstractBoth one-dimensional two-phase Stefan problem with the thermodynamic equilibrium condition u(R(t),t)=0 and with the kinetic rule uε(Rε(t),t)=εRε′(t) at the moving boundary are considered. We prove, when ε approaches zero, Rε(t) converges to R(t) in C1+δ/2[0,T] for any finite T>0, 0<δ<1

Recent advances toward the sustainable management of invasive Xylosandrus ambrosia beetles

We provide an overview of both traditional and innovative control tools for management of three Xylosandrus ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), invasive species with a history of damage in forests, nurseries, orchards and urban areas. Xylosandrus compactus, X. crassiusculus and X. germanus are native to Asia, and currently established in several countries around the globe. Adult females bore galleries into the plant xylem inoculating mutualistic ambrosia fungi that serve as food source for the developing progeny. Tunneling activity results in chewed wood extrusion from entry holes, sap outflow, foliage wilting followed by canopy dieback, and branch and trunk necrosis. Maintaining plant health by reducing physiological stress is the first recommendation for long-term control. Baited traps, ethanol-treated bolts, trap logs and trap trees of selected species can be used to monitor Xylosandrus species. Conventional pest control methods are mostly ineffective against Xylosandrus beetles because of the pests’ broad host range and rapid spread. Due to challenges with conventional control, more innovative control approaches are being tested, such as the optimization of the push–pull strategy based on specific attractant and repellent combinations, or the use of insecticide-treated netting. Biological control based on the release of entomopathogenic and mycoparasitic fungi, as well as the use of antagonistic bacteria, has yielded promising results. However, these technologies still require validation in real field conditions. Overall, we suggest that management efforts should primarily focus on reducing plant stress and potentially be combined with a multi-faceted approach for controlling Xylosandrus damage

Climate and landscape composition explain agronomic practices, pesticide use and grape yield in vineyards across Italy

Context Worldwide, organic farming is being promoted as one of the main alternatives to intensive conventional farming. However, the benefits of organic agriculture are still controversial and need to be tested across wide environmental gradients. Objective Here, we carried out an observational study to test how agronomic practices, pest management, environmental impact and yield of conventional and organic vineyards changed along wide climatic and landscape gradients across Italy. Methods We used a block design with 38 pairs of conventional and organic vineyards across Italy. Results and conclusions Most agronomic practices did not differ between conventional and organic vineyards. By contrast, landscape composition and climate were strong predictors of management in both systems. First, increasing semi-natural areas around the vineyards reduced pesticide pressure and related environmental impacts, but was also associated with lower yield. Second, irrespective of the farming system, a warm and dry climate was associated with reduced fungicide pressure. Conventional farming had a yield gain of 40% in cold and wet climate compared to organic but the yield gap disappeared in the warmest regions. Significance In both farming systems, we observed a large variability in management practices that was mainly explained by climate and landscape composition. This large variability should be considered when evaluating the benefits and drawbacks of different farming systems under contrasting environmental contexts

Geographic distribution of Phyllocoptruta oleivora in the Mediterranean Basin, with particular emphasis on Italy

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Premieres observations sur la dynamique des populations de Trialeurodes vaporariorum (Westwood) et de Bemisia tabaci (Gennadius) (Homopt., Aleurodidae) en serres d'aubergine

National audienc

Unusual Behavior of <i>Xylosandrus compactus</i> (Coleoptera: Scolytinae) on Carob Trees in a Mediterranean Environment

Xylosandrus compactus (Eichhoff), commonly known as the black twig borer, was reported in Sicily (Italy) at the end of 2016, infesting Carob tree (Ceratonia siliqua L.) twigs, large branches, and trunks. Previous research indicated that X. compactus attacks only small twigs and branches, not large branches and tree trunks. This unusual behavior was monitored through the two following years in five sites in Ragusa province (Sicily, Italy). For each of the monitored sites, the diameter of the infested trunks and branches was recorded. Samples of branches and trunks presenting galleries were removed from the trees and analyzed in the laboratory. Xylosandrus compactus occurred on branches of all monitored trees, while the percentage of infested trunks of carob trees ranged from 60% to 80%. Inside the infested galleries, all biological stages of X. compactus were found. Infestations were also recorded on trunks and branches with diameters greater than 80 cm and 30 cm, respectively. The mean number of X. compactus specimens inside the galleries was recorded and gallery shape was described. Unordinary behaviors, like the one described here for the first time, can affect the current efficiency of management recommendations

First record of the Persea Mite Oligonychus perseae (Acari: Tetranychidae) in Italy with a review of the literature

The Persea Mite Oligonychus perseae Tuttle, Baker and Abbatiello, is reported for the first time in Italy. The pest was found on avocado in Sicily (South Italy), in August 2014. The predatory mite Iphiseius degenerans (Berlese) was found in association with O. perseae colonies

Innovation Technology to Empower Safety, Health and Welfare in Agriculture and Agro-food Systems

Abstract Results of trials on mechanical methods to release beneficials and on new techniques to apply sulphur are reported. The former were carried out on two predators, a phytoseiid mite and an anthocorid bug. Laboratory and greenhouse tests were conducted with the aim of evaluating the vitality and the damage eventually caused and setting the machine. The latter dealt with new techniques of sulphur application on tomato crops using dispensers transforming granular sulphur into vapour. In order to evaluate the effects of sublimated sulphur both on fungal diseases and arthropod pests, different trials have been carried out. The incidence and the severity index for airborne pathogens were bi-weekly evaluated and the infestations caused by some of the most relevant pests have been regularly monitored. Moreover, the incidence of the viral disease TYLCD has been evaluated. During the trials on mechanical methods, no physical damage to the beneficials was observed. The distribution in laboratory seems to be suitable for applications in biological control programs, and the results on protected sweet pepper crops showed a better spatial distribution and a more effective interaction beneficials/preys in the &quot;mechanically released&quot; plots than in the &quot;manually released&quot; ones. The trials on sublimated sulphur confirmed the good effectiveness of the technique in controlling natural infection of tomato powdery mildew as well as a moderate efficacy on tomato late blight. A good protection has been registered in the case of arthropod pests: the tomato russet mite was totally controlled; appreciable results were also obtained on phytophagous insects. A significant reduction in viral infections was also observed