scholarly journals Outbreaks of Tomostethus nigritus (Fabricius, 1804) (Hymenoptera, Tenthredinidae) on Fraxinus angustifolia ‘Raywood’ in Belgium

2019 ◽  
Vol 72 ◽  
pp. 67-81
Author(s):  
Fons Verheyde ◽  
Geert Sioen

In Western Europe the ash sawfly Tomostethus nigritus is known to occur at low densities on Fraxinus excelsior and is uncommonly reported as a pest species. However, we show here that outbreaks can occur on non-endemic trees such as F. angustifolia, and that the species is able to spread quickly using city infrastructure. At the visited localities near the city of Ghent, foliage of Fraxinus angustifolia ‘Raywood’ emerged approximately one month earlier than on F. excelsior. At the same time, changed climatic conditions in the last decade, i.e. higher temperatures in March, caused adults to emerge earlier. Synchronicity of the potential hosts and T. nigritus may therefore have altered, playing a crucial role in population dynamics. Future research should aim to confirm if the species dramatically declines in numbers after reaching its peak population level, an effect which was observed in previous studies, but for which there is still no satisfactory explanation.

2020 ◽  
Vol 23 (3-4) ◽  
pp. 91-102
Author(s):  
Ivana Pajač Živković ◽  
Irena Brlić Puškarić ◽  
Darija Lemić

The invasive species Drosophila suzukii (Matsumura, 1931), the spotted wing drosophila, was first recorded in Croatia in 2010. Since then, it has spread on Croatian territory but its presence has not yet been confirmed in the City of Zagreb. In this research population dynamics of D. suzukii was investigated in three orchards in Zagreb (Maksimir, Jelenovac, Zelenjak) in the period from 20th of March to 27th of November 2017. Feeding traps with apple vinegar were used for catching D. suzukii. The flight began in the period from 27th of June to 11th of July and lasted until 27th of November. The total pest catches were 874 specimens (Jelenovac 187, Maksimir 232 and Zelenjak 455). From September to November there was a continuous flight and a large increase in the number of caught flies, suggesting the presence of more overlapping generations. Besides the host plants, the development of the pest in this area is also enabled by suitable climatic conditions. The present population in the City of Zagreb County poses a danger to fruit producers in the Zagreb County. The results of this research are a contribution to better understanding of the population and the spread of the pest in Croatia.


2008 ◽  
Vol 35 (6) ◽  
pp. 487 ◽  
Author(s):  
Jens Jacob ◽  
Grant R. Singleton ◽  
Lyn A. Hinds

Ricefield rats (Rattus argentiventer) in south-east Asian rice fields and house mice (Mus domesticus) in Australian grain fields are major pest species. They cause damage before and after harvest and carry zoonotic diseases. For both species, management techniques have been pursued using the approach of immunocontraceptive vaccination. We review results from a series of enclosure and field studies conducted with these species to assess the effects of fertility control in small rodents. In the experiments, fertility control was simulated by tubal ligation, ovariectomy or progesterone treatment. A once-off sterilisation of 50–75% of enclosed founder females considerably reduced reproductive output of ricefield rat populations until the end of the reproductive period. In house mice, similar success was achieved when a sterility level of 67% of female founders and offspring was maintained. Repeated antifertility treatments are required because of the much longer breeding period of house mice versus ricefield rats. Comparing the results of enclosure trials with the outcome of simulation models suggests that partial compensation of treatment effects can occur through enhanced reproduction of the remaining fertile females and improved survival of juveniles. However, such compensatory effects as well as behavioural consequences of sterility in field populations are not likely to prevent the management effect at the population level. The challenge for effective fertility control of small rodents in the field is the wide-scale delivery of an antifertility treatment to founders at the beginning of the breeding season and to fertile immigrants that are recruited into the population, which otherwise contribute to the reproductive output at the population level. Future research efforts should focus on species-specific techniques and on agents that can be effectively delivered via bait.


1964 ◽  
Vol 96 (1-2) ◽  
pp. 348-356 ◽  
Author(s):  
E. J. LeRoux

AbstractA knowledge of ecological principles is essential to the successful development of future research on pest control problems in Canadian orchard entomology. Such knowledge should be especially helpful in spotlighting omissions in past studies as well as indicating new areas of study in the future. In particular, the ecosystem concept should serve not only as a basis for evaluating and bringing together existing data but also as a guide in the collection, integration and interpretation of new data.Our approach should be to study the population dynamics of major arthropod pests in Canadian apple orchards to obtain data of the fundamental kind on natural populations of these species. Since this approach is dependent on precise measurement of the population and its mortality factors, as well as on the mathematical modelling of the data obtained, unambiguous deduction and greater understanding and utilization of the results would then be possible.Examples from a recent eight-year study of the population dynamics of two pest species in Canadian apple orchards reveal that the fundamental approach to pest problems in Canada is both feasible and practical, and that the results can yield considerable insight into the role of mortality factors in population regulation as well as in control of pest stages of economic importance.


2012 ◽  
Vol 71 (4) ◽  
pp. 299-328
Author(s):  
Armand Van Nimmen

Deze bijdrage handelt over de perikelen in de jaren dertig rond het plan om het lichamelijk overschot van de Vlaamse dichter Paul Van Ostaijen over te brengen uit het klein Waals dorp waar hij in vergetelheid begraven lag onder een houten kruis naar zijn geboortestad Antwerpen. Daar zou hij herbegraven worden op de stedelijke begraafplaats Schoonselhof onder een gepaste denksteen. Zoals meermaals het geval is bij het oprichten van publieke monumenten, verliepen – wegens onderling gekibbel en gebrek aan financiële middelen – meer dan zes jaren vooraleer de oorspronkelijke idee kon verwezenlijkt worden.Aandacht in dit artikel gaat naar Jozef Duysan, bewonderaar van de dichter en uitgesproken flamingant, die een cruciale rol speelde in de conceptie en uitvoering van het initiatief. Ten slotte beschrijft het artikel hoe deze nu bijna totaal vergeten man tijdens de Tweede Wereldoorlog in het vaarwater geraakte van de collaboratie, fungeerde als directeur van het Arbeidsamt in Antwerpen, na de oorlog veroordeeld werd en jaren lang ondergedoken leefde in die stad.________Jozef Duysan’s battle with the angel: Skirmishes around the tomb of Paul Van OstaijenThis contribution reports the vicissitudes concerning the plan dating from the nineteen thirties to transfer the mortal remains of the Flemish poet Paul Van Ostaijen from the small Walloon village where he was buried in oblivion under a wooden cross to Antwerp, the city of his birth. He was to be reburied there on the municipal cemetery Schoonselhof under a fitting memorial headstone. As frequently happens on the occasion of creating public monuments, more than six years passed before the original idea could be carried out – because of internal bickering and lack of financial means. This article focuses on Jozef Duysan, an admirer of the poet and an explicit Flemish militant, who played a crucial role in the concept and realisation of the initiative. In conclusion the article recounts how this man who has been practically completely forgotten now,  ventured into the deep waters of the collaboration during the Second World War, how he acted as director of the Arbeidsamt in Antwerp and how he was convicted after the war and lived for many years in hiding in that city.


Author(s):  
Daniel W. Berman

Foundation myths are a crucial component of many Greek cities’ identities. But the mythic tradition also represents many cities and their spaces before they were cities at all. This study examines three of these ‘prefoundational’ narratives: stories of cities-before-cities that prepare, configure, or reconfigure, in a conceptual sense, the mythic ground for foundation. ‘Prefoundational’ myths vary in both form and function. Thebes, before it was Thebes, is represented as a trackless and unfortified backwater. Croton, like many Greek cities in south Italy, credited Heracles with a kind of ‘prefounding’, accomplished on his journey from the West back to central Greece. And the Athenian acropolis was the object of a quarrel between Athena and Poseidon, the results of which gave the city its name and permanently marked its topography. In each case, ‘prefoundational’ myth plays a crucial role in representing ideology, identity, and civic topography.


2020 ◽  
Vol 37 (9) ◽  
pp. 2691-2698 ◽  
Author(s):  
Xiaoming Liu

Abstract The prehistoric demography of human populations is an essential piece of information for illustrating our evolution. Despite its importance and the advancement of ancient DNA studies, our knowledge of human evolution is still limited, which is also the case for relatively recent population dynamics during and around the Holocene. Here, we inferred detailed demographic histories from 1 to 40 ka for 24 population samples using an improved model-flexible method with 36 million genome-wide noncoding CpG sites. Our results showed many population growth events that were likely due to the Neolithic Revolution (i.e., the shift from hunting and gathering to agriculture and settlement). Our results help to provide a clearer picture of human prehistoric demography, confirming the significant impact of agriculture on population expansion, and provide new hypotheses and directions for future research.


2021 ◽  
Vol 7 (2) ◽  
pp. 111
Author(s):  
María Jesús Carrasco-Santos ◽  
Antonio Manuel Ciruela-Lorenzo ◽  
Juan Gabriel Méndez Pavón ◽  
Carmen Cristófol Rodríguez

This research analyzed the online reputation of Marbella as a tourist destination and the profiles of the reviewers according to sociodemographic characteristics. A correlational, quantitative research technique was used in this study based on the manual extraction of more than 4000 reviews generated on TripAdvisor. The data used in this study were collected from the TripAdvisor website, taking, as a sample, tourists who had visited the city in the last three years. Ratings that did not provide full data on the variables were excluded. The findings show that Marbella is considered a luxury shopping destination. The preliminary conclusions allow us to generalize about the sociodemographic profile of its tourists. The findings of the study will provide valuable information for Marbella’s Destination Management Organization (DMO). On the one hand, this study highlights the importance of ranking the attractions of the city to create better communication strategies and enhance the appeal of those attractions that receive the best ratings, establishing the true vocation of Marbella as a tourist destination. On the other hand, it provides information on what tourists perceive to be negative elements, allowing the administration to create an improvement plan. The novelty of this research paper is that it delves into Marbella’s online reputation through an analysis of specific attractions’ ratings. Areas that require further attention in future research have been highlighted, along with specific advice on each attraction that contributes to the tourist offerings of the city.


Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 479
Author(s):  
Julian Laabs ◽  
Daniel Knitter

In this study, we present a transparent and reproducible approach to model agricultural production with respect to environmental characteristics and available labour. Our research focuses on the city of Pergamon and its surroundings, with an emphasis on the transition between the Hellenistic and Roman Imperial Period, where widespread demographic changes took place. We investigated the degree of local self-sufficiency using different concepts of a city’s complementary region. Using simple topographic derivatives, we derive a measure of environmental suitability that we translate into a carrying capacity index. Our results show that workforce was not a limiting factor for local self-sufficiency. However, environmental carrying capacity may have been limiting in a scenario with a large population. An active investment into the environment, e.g., by the construction of terraces, could have helped to increase the degree of self-sufficiency. Future research should investigate the level of resilience of such a coupled socio-ecological system in relation to environmental and socio-cultural dynamics.


Urban Studies ◽  
2020 ◽  
pp. 004209802097265
Author(s):  
Matthew Thompson ◽  
Alan Southern ◽  
Helen Heap

This article revisits debates on the contribution of the social economy to urban economic development, specifically focusing on the scale of the city region. It presents a novel tripartite definition – empirical, essentialist, holistic – as a useful frame for future research into urban social economies. Findings from an in-depth case study of the scale, scope and value of the Liverpool City Region’s social economy are presented through this framing. This research suggests that the social economy has the potential to build a workable alternative to neoliberal economic development if given sufficient tailored institutional support and if seen as a holistic integrated city-regional system, with anchor institutions and community anchor organisations playing key roles.


2021 ◽  
pp. 009385482110067
Author(s):  
Daniel K. Pryce ◽  
Ajima Olaghere ◽  
Robert A. Brown ◽  
Vondell M. Davis

The relationship between the police and African Americans has had a contentious history for decades. To explore this topic further, we interviewed 77 African Americans in the City of Durham, NC, about the declining relationship between their community and the police. We find that African Americans’ perceptions of the police are nuanced and complicated by personal experiences, vicarious experiences of relatives and friends, and news from social media and television regarding policing practices and treatment, including police harassment and/or brutality. We characterize these direct and vicarious experiences as the transmission of trauma. Even for the proportion of African Americans who had positive perceptions and interactions with the police, their views of the police seemed to be further complicated by broader concerns of discriminatory treatment. We proffer solutions to improve the relationship between the police and African Americans. The implications of our findings for future research are also discussed.


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