Morphological updating on the basis of integrated DTMs: study on the Albano and Nemi craters

The Colli Albani Volcano has recently developed particular interest in the geophysical community for some peculiar characteristics imputable to a recent residual volcanic activity, thus evidencing that it cannot be considered extinguished yet. On April 2006 an airborne laser scanning (ALS) survey of the Albano and Nemi craters has been carried out to obtain a high resolution digital terrain model (DTM) of the area. We have compared the accuracy of the ALS heights with those obtained by a fast GPS kinematic survey, obtaining maximum deviation within 50 cm. Then, we have integrated the ALS survey of the craters and the bathymetry of the Albano lake to achieve a complete DTM, useful for morphological studies. In addition, with a GNSS/RTK survey (July 2007) we have estimated the Albano and Nemi mean lake levels respectively at 288.16 m and 319.02 m (asl). Based on the integrated DTM and the newly estimated water level values, we have evaluated about 21.7 106 of m3 the water volume loss of the Albano lake from 1993 to 2007, with an average rate of about 1.6 106 m3/yr. © 2008, de Gruyter. All rights reserved

Extending the vibroscape to agroecosystems: investigating the influence of abiotic factors and monitoring insect vibrational signaling

Environmental conditions are crucial factors that influence communication systems and affect animal behavior. Research in the field of biotremology has improved our understanding of insect behavior, ecology, and evolution. However, the interactions between vibrational signaling and environmental factors are less studied, mainly because of technical issues faced in field trials. We therefore developed and tested an approach to investigate the effect of abiotic factors on insect vibrational signaling and explored its implementation as a monitoring tool for insect vibrational signals, using a vineyard as an agroecosystem model. Our results showed a significant decrease in insect signaling activity during unsuitable conditions of high temperature and wind velocity. We determined for the first time, the daily signaling pattern of the two insect pests, Scaphoideus titanus and Halyomorpha halys, in natural conditions. Biotremology techniques could be profitably used to monitor not only the presence of target pest species but also the biodiversity associated with vibrational signaling insects. In particular, the method implemented in this study could be used as a tool to compare the quality of cultivated areas under different management system

Inter-Plant Vibrational Communication in a Leafhopper Insect

Vibrational communication is one of the least understood channels of communication. Most studies have focused on the role of substrate-borne signals in insect mating behavior, where a male and a female establish a stereotyped duet that enables partner recognition and localization. While the effective communication range of substrate-borne signals may be up to several meters, it is generally accepted that insect vibrational communication is limited to a continuous substrate. Until now, interplant communication in absence of physical contact between plants has never been demonstrated in a vibrational communicating insect. With a laser vibrometer we investigated transmission of natural and played back vibrational signals of a grapevine leafhopper, Scaphoideus titanus, when being transmitted between leaves of different cuttings without physical contact. Partners established a vibrational duet up to 6 cm gap width between leaves. Ablation of the antennae showed that antennal mechanoreceptors are not essential in detection of mating signals. Our results demonstrate for the first time that substrate discontinuity does not impose a limitation on communication range of vibrational signals. We also suggest that the behavioral response may depend on the signal intensity

Detection and characterization of incidental vibrations from Drosophila suzukii in infested fruits

The spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), is an invasive species native to East Asia and now widespread worldwide. Major economic damage is caused by the larvae developing within ripening soft-skin fruit. Currently, larval detection in fruit is limited to destructive methods and post-harvest control strategies heavily rely on the use of chemicals or cold to inhibit egg eclosion and larval growth. Feeding larvae are likely to induce substrate-borne vibrations in the berry that could be exploited as cues by predators or to develop a non-invasive pest detection method, an approach previously applied on leaves and wooden structures, but never on fresh fruit. We used a laser vibrometer to detect and characterize the incidental vibrations produced by D. suzukii larvae within fresh blueberries at five different pest age (48, 96, 168, 216 and 264 h). An innovative statistical analysis was performed to assess if infestation level (number of pupae) and pest age (hours after exposure) affect the spectrum and the amplitude of vibrations. The recordings of infested berries were characterized by the presence of a series of broad-band pulses (frequency range 0.1–2 kHz) without a regular temporal pattern, in an amplitude range between 12.1 and 946 μm/s. Furthermore, the analysis revealed the possibility to distinguish between different pest ages and infestation levels. By a spectral analysis of the recordings, the pest ages can be distinguished among each other, but for the age groups at 168 and 216 h after infestation. The vibration amplitude trend gradually increased up to 168–216 h after infestation, and then decreased until fly emergence. Low-infested blueberries showed a faster D. suzukii development time compared to high-infested blueberries. This was reflected into vibrational recordings, as low-infested blueberries exhibited peak amplitude at earlier stage compared to high-infested ones. Results suggest that D. suzukii larvae induce detectable vibrations by feeding within berries that are dependent on infestation level and pest age. We discuss the possible ecological role of such vibrations as cues for unintended receivers, such as predators and parasitoids, and their potential for innovative infestation detection method

Exploitation of Insect Vibrational Signals Reveals a New Method of Pest Management

Food production is considered to be the main source of human impact on the environment and the concerns about detrimental effects of pesticides on biodiversity and human health are likely to lead to an increasingly restricted use of chemicals in agriculture. Since the first successful field trial, pheromone based mating disruption enabled sustainable insect control, which resulted in reduced levels of pesticide use. Organic farming is one of the fastest growing segments of agriculture and with the continuously growing public concern about use of pesticides, the main remaining challenge in increasing the safety of the global food production is to identify appropriate alternative mating disruption approaches for the numerous insect pests that do not rely on chemical communication. In the present study, we show for the first time that effective mating disruption based on substrate-borne vibrational signals can be achieved in the field. When disruptive vibrational signals were applied to grapevine plants through a supporting wire, mating frequency of the leafhopper pest Scaphoideus titanus dropped to 9 % in semi-field conditions and to 4 % in a mature vineyard. The underlying mechanism of this environmentally friendly pest-control tactic is a masking of the vibrational signals used in mate recognition and location. Because vibrational communication is widespread in insects, mating disruption using substrate vibrations can transform many open field and greenhouse based farming systems

Mit Vibrationen gegen Weisse Fliegen - eine neue Methode zur Bekämpfung der Gewächshausmottenschildlaus

Weisse Fliegen sind gefürchtete Schädlinge in einer Vielzahl von Gemüsekulturen. Insbesondere die Gewächshausmottenschildlaus verursacht durch Bildung von Russtau auf den Früchten oder die Übertragung von Viren beträchtliche Schäden an Gewächshauskulturen wie Tomaten, Peperoni oder Gurken. Im europäischen Forschungsprojekt RELACS wurde in den letzten Jahren nach neuen Bekämpfungsmethoden gegen den Schädling gesucht. Erfolgsversprechend scheint insbesondere ein Ansatz zur Verwirrungstechnik mittels Vibrationssignalen zu sein

Vibrational calling signals improve the efficacy of pheromone traps to capture the brown marmorated stink bug

Halyomorpha halys (Stål, 1855), the brown marmorated stink bug (BMSB), is an invasive species that has become a key agricultural pest in its invaded range. Commercial traps available for BMSB monitoring rely on male produced aggregation pheromones as lure, with two possible shortcomings: trap spillover and low detection precision. In this study, we assessed if vibrational signals can increase the attractiveness of pheromone traps by testing the optimized vibration-based lure (Female Song 2, FS2) associated with a specifically designed trap (i.e., the vibrotrap). We evaluated the efficacy of this bimodal trap (i.e., pheromones + vibrations) on females, males and nymphs in controlled conditions (greenhouse) and in the field, in two sites at the margin of two commercial vineyards. In the field, bimodal vibrotraps were compared to three unimodal (i.e., only pheromone) trap types. Both experiments showed that the vibrotrap is highly attractive for BMSB, and the optimized FS2 signal significantly improved its effectiveness. Even though FS2 was selected to target males, the number of trapped females increased as well. Overall, the presented findings show a feasible improvement to future commercial BMSB traps through the synergic use of semiophysicals and semiochemicals. Further research is needed to evaluate the effectiveness of vibrotraps for both early detection and mass trapping

Orientus ishidae (Hemiptera: Cicadellidae): biology, direct damage and preliminary studies on apple proliferation infection in apple orchard

The mosaic leafhopper, Orientus ishidae (Matsumura), is an Asian species widespread in Europe that can cause leaf damage in wild trees and transmit disease phytoplasmas to grapevines. Following an O. ishidae outbreak reported in 2019 in an apple orchard in northern Italy, the biology and damage caused by this species to apples were investigated during 2020 and 2021. Our studies included observations on the O. ishidae life cycle, leaf symptoms associated to its trophic activity, and its capability to acquire "Candidatus Phytoplasma mali," a causal agent of Apple Proliferation (AP). The results indicate that O. ishidae can complete the life cycle on apple trees. Nymphs emerged between May and June, and adults were present from early July to late October, with the peak of flight between July and early August. Semi-field observations allowed for an accurate description of leaf symptoms that appeared as a distinct yellowing after a one-day exposure. In field experiments, 23% of the leaves were found damaged. In addition, 16-18% of the collected leafhoppers were found carrying AP phytoplasma. We conclude that O. ishidae has the potential to be a new apple tree pest. However, further studies are required to better understand the economic impact of the infestations

Effects of irradiation on biology and mating behaviour of wild males of brown marmorated stink bug using a 6 MV medical linear accelerator

The brown marmorated stink bug, Halyomorpha halys, is a pentatomid bug of Eastern Asian origin that became an economically relevant pest in the Eurasian and American continents. Management of this species is limited to use of chemical insecticides: an inefficient method due to the strong adaptability of the target pest. The sterile insect technique (SIT) is potentially a valid tactic in the search for nontoxic alternatives. In this work, we investigated the suitability of masstrapped overwintering males, collected during the aggregation phase before the winter diapause, for their release as competitive sterile males in an SIT programme. Differently from previous studies, irradiation was applied with a linear accelerator device that produced high-energy photons. Following a similar scientific protocol with newly emerged irradiated males, the effects of X-ray irradiation on physiological parameters (longevity, fecundity and fertility) were assessed. In addition, behavioural bioassays were carried out in no-choice conditions to evaluate if irradiation interferes with mating processes. The results are very encouraging; the effects of the irradiation at 32 Gy did not differ from the controls in the longevity or fecundity of the exposed overwintering adults. The hatching rate of the eggs laid by the fertile females that had mated with the irradiated males was less than 5%. The results of behavioural bioassays showed that the irradiation did not cause a significant impact on the quality of the sterile males. More research is warranted to evaluate the mating competitiveness of sterile males in semi-field and field condition