scholarly journals Species-Specificity in Thermopreference and CO2-Gated Heat-Seeking in Culex Mosquitoes

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 92
Author(s):  
Joanna M. Reinhold ◽  
Karthikeyan Chandrasegaran ◽  
Helen Oker ◽  
José E. Crespo ◽  
Clément Vinauger ◽  
...  
Keyword(s):  
Host Preference ◽  
Mosquito Species ◽  
Co2 Concentration ◽  
Culex Mosquito ◽  
Host Seeking ◽  
Wide Range ◽  
Cold Blood ◽  
Seeking Behavior ◽  
Thermal Stimuli

Combining thermopreference (Tp) and CO2-gated heat-seeking assays, we studied the thermal preferendum and response to thermal cues in three Culex mosquito species exhibiting differences in native habitat and host preference (e.g., biting cold and/or warm-blooded animals). Results show that these species differ in both Tp and heat-seeking behavior. In particular, we found that Culex territans, which feed primarily on cold-blood hosts, did not respond to heat during heat-seeking assays, regardless of the CO2 concentration, but exhibited an intermediate Tp during resting. In contrast, Cx. quinquefasciatus, which feeds on warm blooded hosts, sought the coolest locations on a thermal gradient and responded only moderately to thermal stimuli when paired with CO2 at higher concentrations. The third species, Cx. tarsalis, which has been shown to feed on a wide range of hosts, responded to heat when paired with high CO2 levels and exhibited a high Tp. This study provides the first insights into the role of heat and CO2 in the host seeking behavior of three disease vectors in the Culex genus and highlights differences in preferred resting temperatures.

scholarly journals Mosquito Host Seeking in 3D Using a Versatile Climate-Controlled Wind Tunnel System

2021 ◽  
Vol 15 ◽  
Author(s):  
Annika Hinze ◽  
Jörgen Lantz ◽  
Sharon R. Hill ◽  
Rickard Ignell
Keyword(s):  
Climate Change ◽  
Wind Tunnel ◽  
Climatic Conditions ◽  
Flight Behavior ◽  
Future Studies ◽  
Host Seeking ◽  
Seeking Behavior ◽  
Tunnel System

Future anthropogenic climate change is predicted to impact sensory-driven behaviors. Building on recent improvements in computational power and tracking technology, we have developed a versatile climate-controlled wind tunnel system, in which to study the effect of climate parameters, including temperature, precipitation, and elevated greenhouse gas levels, on odor-mediated behaviors in insects. To establish a baseline for future studies, we here analyzed the host-seeking behavior of the major malaria vector mosquito, Anopheles gambiae sensu strico, to human odor and carbon dioxide (CO2), under tightly controlled climatic conditions, and isolated from potential background contamination by the presence of an experimenter. When presented with a combination of human foot odor and CO2 (case study I), mosquitoes engaged in faster crosswind flight, spent more time in the filamentous odor plume and targeted the odor source more successfully. In contrast, female An. gambiae s. s. presented with different concentrations of CO2 alone, did not display host-seeking behavior (case study II). These observations support previous findings on the role of human host-associated cues in host seeking and confirm the role of CO2 as a synergist, but not a host-seeking cue on its own. Future studies are aimed at investigating the effect of climate change on odor-mediated behavior in mosquitoes and other insects. Moreover, the system will be used to investigate detection and processing of olfactory information in various behavioral contexts, by providing a fine-scale analysis of flight behavior.

scholarly journals Oxidase, Esterase, and KDR-Associated Pyrethroid Resistance in Culex quinquefasciatus Field Collections of Collier County, Florida

2020 ◽  
Vol 36 (1) ◽  
pp. 22-32
Author(s):  
Keira J. Lucas ◽  
Rachel B. Bales ◽  
Kaci McCoy ◽  
Caroline Weldon
Keyword(s):  
Pyrethroid Resistance ◽  
Mosquito Species ◽  
Linear Regression Analysis ◽  
Resistance Mechanism ◽  
Point Mutations ◽  
Culex Mosquito ◽  
Collier County ◽  
Wide Range ◽  
Knockdown Effect ◽  
Control And Prevention

ABSTRACT In several insect species, resistance to pyrethroids and DDT (dichlorodiphenyltrichloroethane) is linked to point mutations in the voltage-gated sodium channel (VGSC) gene. Pyrethroid-based insecticides prolong the opening of sodium channels, causing paralysis known as a “knockdown” effect before mortality occurs. Point mutations in the VGSC gene result in decreased pyrethroid binding and reduced sensitivity to the insecticide—this resistance mechanism is known as knockdown resistance (kdr) as insects do not die but recover from paralysis with time. In Culex mosquito species loss of target site sensitivity to pyrethroids is linked to a number of substitutions, one of which is leucine (L) to phenylalanine (F) at residue 1014 (L1014F) in the VGSC gene. Here we report the identification of kdr-associated pyrethroid resistance and developing resistance in Cx. quinquefasciatus field collections from Collier County, FL. Evaluation of position 1014 of the VGSC in Cx. quinquefasciatus collections from 7 locations in Collier County, FL, revealed a wide range of genotypes from one part of the district to the other. Centers for Disease Control and Prevention bottle bioassay, linear regression analysis, and cage trial evaluations suggest that the L1014F mutation plays a role, at least in part, to the pyrethroid resistance status of Cx. quinquefasciatus collected in Collier County, FL. Furthermore, we identified resistance attributed to both oxidase and esterase activity, indicating that multiple mechanisms are responsible for pyrethroid resistance in Collier County Cx. quinquefasciatus.

scholarly journals Bats and ticks: host selection and seasonality of bat-specialist ticks in eastern Europe

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Attila D. Sándor ◽  
Alexandra Corduneanu ◽  
Áron Péter ◽  
Andrei Daniel Mihalca ◽  
Levente Barti ◽  
...  
Keyword(s):  
Host Specificity ◽  
Tick Species ◽  
Hard Tick ◽  
East Europe ◽  
South East Europe ◽  
Host Seeking ◽  
Wide Range ◽  
Seeking Behavior ◽  
Report Data ◽  
Host Parasite

Abstract Background Parasites may actively seek for hosts and may use a number of adaptive strategies to promote their reproductive success and host colonization. These strategies will necessarily influence their host specificity and seasonality. Ticks are important ectoparasites of vertebrates, which (in addition to directly affecting their hosts) may transmit a number of pathogens. In Europe, three hard tick species (Ixodidae: Ixodes ariadnae, I. simplex and I. vespertilionis) and at least two soft tick species (Argasidae: Argas transgariepinus and A. vespertilionis) are specialized for bats. Methods Here we report data on the host range of these ticks and the seasonality of tick infestation on wild caught bats in south-east Europe. We collected 1803 ticks from 30 species of bats living in underground shelters (caves and mines) from Romania and Bulgaria. On the basis of tick–host associations, we tested several hypotheses on host–parasite evolutionary adaptations regulating host specificity, seasonality and sympatric speciation. Results We observed significant differences in host specificity and seasonality of abundance between the morphologically different bat specialist ticks (I. simplex and I. vespertilionis) likely caused by their host choice and their respective host-seeking behavior. The two highly generalist, but morphologically similar tick species (I. ariadnae and I. vespertilionis) showed temporal differences in occurrence and activity, thus exploiting significantly different host communities while occurring in geographical sympatry. Conclusions We conclude that bat-specialist ticks show a wide range of adaptations to their hosts, with differences in specificity, seasonality of occurrence, the prevalence and intensity of infestation and all these contribute to a successful division of temporal niches of ticks sharing morphologically similar hosts occurring in geographical sympatry.

scholarly journals Evidence of Adaptive Evolution in Wolbachia-Regulated Gene DNMT2 and Its Role in the Dipteran Immune Response and Pathogen Blocking

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1464
Author(s):  
Tamanash Bhattacharya ◽  
Danny W. Rice ◽  
John M. Crawford ◽  
Richard W. Hardy ◽  
Irene L. G. Newton
Keyword(s):  
Immune Response ◽  
Positive Selection ◽  
Mosquito Species ◽  
Fruit Fly ◽  
Host Protein ◽  
Wide Range ◽  
Regulation Function ◽  
Specific Factors ◽  
And Function

Eukaryotic nucleic acid methyltransferase (MTase) proteins are essential mediators of epigenetic and epitranscriptomic regulation. DNMT2 belongs to a large, conserved family of DNA MTases found in many organisms, including holometabolous insects such as fruit flies and mosquitoes, where it is the lone MTase. Interestingly, despite its nomenclature, DNMT2 is not a DNA MTase, but instead targets and methylates RNA species. A growing body of literature suggests that DNMT2 mediates the host immune response against a wide range of pathogens, including RNA viruses. Curiously, although DNMT2 is antiviral in Drosophila, its expression promotes virus replication in mosquito species. We, therefore, sought to understand the divergent regulation, function, and evolution of these orthologs. We describe the role of the Drosophila-specific host protein IPOD in regulating the expression and function of fruit fly DNMT2. Heterologous expression of these orthologs suggests that DNMT2′s role as an antiviral is host-dependent, indicating a requirement for additional host-specific factors. Finally, we identify and describe potential evidence of positive selection at different times throughout DNMT2 evolution within dipteran insects. We identify specific codons within each ortholog that are under positive selection and find that they are restricted to four distinct protein domains, which likely influence substrate binding, target recognition, and adaptation of unique intermolecular interactions. Collectively, our findings highlight the evolution of DNMT2 in Dipteran insects and point to structural, regulatory, and functional differences between mosquito and fruit fly homologs.

The role of different Culex mosquito species in the transmission of West Nile virus and avian malaria parasites in Mediterranean areas

2020 ◽  
Author(s):  
Martina Ferraguti ◽  
Hans Heesterbeek ◽  
Josué Martínez‐de la Puente ◽  
Miguel Ángel Jiménez‐Clavero ◽  
Ana Vázquez ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Avian Malaria ◽  
Mosquito Species ◽  
Culex Mosquito ◽  
West Nile ◽  
Malaria Parasites ◽  
Mediterranean Areas ◽  
Avian Malaria Parasites

scholarly journals The role of proboscis of the malaria vector mosquito Anopheles stephensi in host-seeking behavior

2011 ◽  
Vol 4 (1) ◽  
pp. 10 ◽  
Author(s):  
Emi Maekawa ◽  
Hiroka Aonuma ◽  
Bryce Nelson ◽  
Aya Yoshimura ◽  
Fumio Tokunaga ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Host Seeking ◽  
Vector Mosquito ◽  
Seeking Behavior

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Introduction: Emotion, History and the Arts

2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild
Keyword(s):  
Historical Change ◽  
Carson Mccullers ◽  
Emotional Life ◽  
Review Section ◽  
The Arts ◽  
Wide Range ◽  
War Correspondents ◽  
History Of ◽  
Johan Huizinga

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

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