Acibenzolar-S-methyl may prevent vector-mediated flavescence dorée phytoplasma transmission, but is ineffective in inducing recovery of infected grapevines.

BACKGROUND: Acibenzolar-S-methyl (BTH), a functional analogue of salicylic acid (SA), is known to elicit a systemic resistance across a broad range of plant-pathogen interactions, but so far it has not been tested against flavescence dorée (FDP), one of the most devastating grapevine diseases. The aim of this work was to evaluate the activity of BTH in preventing FDP transmission by the insect vector and in inducing recovery of infected grapevines. RESULTS: Repeated 2 mM applications of BTH to test grapevine cuttings (cv. Barbera) exposed to adults of the infectious vector Scaphoideus titanus Ball reduced the rate of infected plants. The effect was not recorded following similar BTH applications to highly susceptible young in vitro propagated vines. A high natural recovery rate (more than 70%) was observed over a 3 year period in field-infected grapevines of the same cultivar. Under these conditions, BTH repeated applications over the whole period clearly failed to increase recovery of field-infected grapevines. CONCLUSION: Following a 3 year experiment, it can be concluded that, although high doses and repeated applications of BTH reduced vector transmission of FDP, BTH was ineffective in inducing recovery of FDP-infected grapevines cv. Barbera under field conditions. © 2016 Society of Chemical Industry.

Adaptation of indigenous larval parasitoids to Tuta absoluta (Lepidoptera: Gelechiidae) in Italy.

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious threat to tomato (Solanum lycopersicum L.) crops in South America. In Europe, after its first detection in Spain in 2006, it rapidly spread through the Mediterranean basin, reaching Italy 2 yr later. The aim of our work was to find indigenous effective biological control agents and to evaluate their potential role in the control of larval populations of T. absoluta in controlled conditions. Nine species of larval parasitoids emerged from field-collected tomato leaves infested by T. absoluta. The most abundant, Necremnus near artynes (Walker) and Necremnus near tidius (Walker) (Hymenoptera: Eulophidae), were tested in laboratory parasitism trials. Furthermore, because the species N. artynes and N. tidius are each reported in literature as an ectoparasitoid of Cosmopterix pulchrimella Chambers (Lepidoptera: Cosmopterigidae) on upright pellitory plants, olfactometer bioassays were performed to assess the response of our parasitoids to the odors of tomato and pellitory leaves infested by T absoluta and C. pulchrimella, respectively, compared with healthy ones. Both Necremnus species showed good adaptation to the invasive pest, and we observed a high larval mortality of T. absoluta because of host feeding and parasitism. Even olfactory responses highlighted a preference of both wasps for tomato plants infested by the exotic pest. These preliminary results demonstrated a high suitability of these indigenous natural enemies for controlling T. absoluta. Further investigations are needed to confirm their role as potential biological agents in commercial tomato plantations.

Usability study of a vineyard teleoperated compost spreader.

Teleoperation has been widely applied in modern industry because of a variety of advantages, such as providing replaceable surrogates for humans in dangerous or difficult working environments over long distances. In this paper, a usability evaluation study of a teleoperation system for a compost spreader robotic machine is presented. The machine has been designed for the application of compost in small and stepping parcels of hilly vineyards. Driving and working tasks can be controlled remotely by a portable piloting unit, reducing the risk for the operator in the event of machine overturning. Participants of the study were asked to perform a series of tasks and sub-tasks and to vocalize their thoughts while working with the machine. The tasks were designed to simulate typical user experience. Once all the tasks were accomplished each participant was asked to fill a questionnaire. The evaluation considered aspects such as learnability, ease of use, understandability, controllability, frustration, mental effort, distraction, clarity of presentation, perceived usefulness, temporal efficiency and machine aesthetic. Results show that usability evaluation helped detecting design deficiencies in the teleoperated compost spreader machine.