scholarly journals Host Associations Of Biting Midges (Diptera: Ceratopogonidae: Culicoides) Near Sentinel Chicken Surveillance Locations In Florida, USA

2019 ◽  
Vol 35 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Kristin E. Sloyer ◽  
Carolina Acevedo ◽  
Alfred E. Runkel ◽  
Nathan D. Burkett-Cadena
Keyword(s):  
Mosquito Control ◽  
Pathogen Transmission ◽  
Host Use ◽  
Culicoides Species ◽  
Biting Midges ◽  
Total Blood ◽  
Avian Blood ◽  
Vector Borne ◽  
Arbovirus Surveillance ◽  
Blood Meals

ABSTRACT Quantifying host use is important for understanding transmission of vector-borne pathogens. Despite the importance of biting midges (Diptera: Ceratopogonidae) in pathogen transmission, the vector–host relationships of most Culicoides species are poorly documented, even in locations where active arbovirus surveillance is conducted. Polymerase chain reaction–based blood-meal analysis was performed on 663 blood-engorged Culicoides females collected by 7 Florida mosquito control districts at 24 sentinel chicken arbovirus surveillance sites in 2017. A total of 638 blood meals were successfully analyzed to determine host species source, representing 11 Culicoides species. The most commonly bitten host was domestic chicken (Gallus gallus) (presumably sentinel chickens), constituting 565 of 638 (88.6%) the total blood meals. Other common hosts included humans (5.8%), white-tailed deer (Odoocoileus virginianus) (2.5%), and brown basilisk (Basiliscus vittatus) (1.6%). Significant differences in distribution of mammal and avian blood meals were found for a number of Culicoides species, and these patterns did not vary across locations. These results indicate that sentinel chickens are exposed to bites by Culicoides, potentially exposing them to Culicoides-borne pathogens. The findings that vertebrate host use was consistent across locations suggests that each Culicoides species has affinity for one or more specific animal groups, and does not feed randomly upon available animals.

scholarly journals A Review of Studies Evaluating Insecticide Barrier Treatments for Mosquito Control From 1944 to 2018

2019 ◽  
Vol 13 ◽  
pp. 117863021985900 ◽  
Author(s):  
Craig A Stoops ◽  
Whitney A Qualls ◽  
Thuy-Vi T Nguyen ◽  
Stephanie L Richards
Keyword(s):  
Mosquito Control ◽  
Mosquito Species ◽  
The United States ◽  
Pathogen Transmission ◽  
Control Efficacy ◽  
Vector Borne Diseases ◽  
Control Programs ◽  
Potential Development ◽  
Lambda Cyhalothrin ◽  
Vector Borne

Background and Purpose: Barrier insecticide treatments have a long history in mosquito control programs but have been used more frequently in the United States in recent years for control of invasive “backyard” species (eg, Aedes albopictus) and increases in incidence of vector-borne diseases (eg, Zika). Methods: We reviewed the published literature for studies investigating barrier treatments for mosquito control during the last 74 years (1944-2018). We searched databases such as PubMed, Web of Science, and Google Scholar to retrieve worldwide literature on barrier treatments. Results: Forty-four studies that evaluated 20 active ingredients (AIs) and 21 formulated products against multiple mosquito species are included. Insecticides investigated for efficacy included organochlorines (dichlorodiphenyltrichloroethane [DDT], β-hexachlorocyclohexane [BHC]), organophosphates (malathion), and pyrethroids (bifenthrin, deltamethrin, permethrin, lambda-cyhalothrin) as AIs. Study design varied with multiple methods used to evaluate effectiveness of barrier treatments. Barrier treatments were effective at lowering mosquito populations although there was variation between studies and for different mosquito species. Factors other than AI, such as exposure to rainfall and application equipment used, also influenced control efficacy. Conclusions: Many of the basic questions on the effectiveness of barrier insecticide applications have been answered, but several important details still must be investigated to improve precision and impact on vector-borne pathogen transmission. Recommendations are made to assist future evaluations of barrier treatments for mosquito control and to limit the potential development of insecticide resistance.

scholarly journals Blood-feeding ecology of mosquitoes in two zoological gardens in the United Kingdom

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Arturo Hernandez-Colina ◽  
Merit Gonzalez-Olvera ◽  
Emily Lomax ◽  
Freya Townsend ◽  
Amber Maddox ◽  
...  
Keyword(s):  
Host Species ◽  
Disease Transmission ◽  
Mosquito Control ◽  
Blood Feeding ◽  
Pathogen Transmission ◽  
Host Feeding ◽  
Prevention Measures ◽  
Diverse Range ◽  
Generalized Linear Modelling ◽  
Blood Meals

Abstract Background Zoological gardens contain unique configurations of exotic and endemic animals and plants that create a diverse range of developing sites and potential sources of blood meals for local mosquitoes. This may imply unusual interspecific pathogen transmission risks involving zoo vertebrates, like avian malaria to captive penguins. Understanding mosquito ecology and host feeding patterns is necessary to improve mosquito control and disease prevention measures in these environments. Methods Mosquito sampling took place in Chester Zoo for 3 years (2017, 2018, and 2019) and for 1 year in Flamingo Land (2017) using different trapping methods. Blood-fed mosquitoes were identified and their blood meal was amplified by PCR, sequenced, and blasted for host species identification. Results In total, 640 blood-fed mosquitoes were collected [Culex pipiens (n = 497), Culiseta annulata (n = 81), Anopheles maculipennis s.l. (n = 7), An. claviger (n = 1), and unidentifiable (n = 55)]. Successful identification of the host species was achieved from 159 blood-fed mosquitoes. Mosquitoes fed on birds (n = 74), non-human mammals (n = 20), and humans (n = 71). There were mixed blood meals from two hosts (n = 6). The proportions of blood-fed mosquitoes varied across sampling seasons and sites within the zoos. The use of resting traps and aspiration of vegetation were more efficient techniques for capturing blood-fed mosquitoes than traps for host-seeking or gravid mosquitoes. By relating the locations of zoo vertebrates to where fed mosquitoes were trapped, the minimum travelling distances were calculated (13.7 to 366.7 m). Temperature, precipitation, relative humidity, proximity to zoo vertebrate exhibits, and vegetation level were found to be significantly associated with the proportion of captured blood-fed mosquitoes by generalized linear modelling. Conclusions Mosquito feeding behaviour in zoos is mainly influenced by time, location (sampling area), temperature, and host availability, which highlights the value of mosquito monitoring in complex settings to plan control strategies and potentially reduce inherent disease transmission risks for humans and threatened zoo vertebrates. Graphic abstract

scholarly journals Understanding mosquito host-choice behaviour: a new and low-cost method of identifying the sex of human hosts from mosquito blood meals

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fiona Teltscher ◽  
Sophie Bouvaine ◽  
Gabriella Gibson ◽  
Paul Dyer ◽  
Jennifer Guest ◽  
...  
Keyword(s):  
Blood Meal ◽  
Host Species ◽  
Disease Transmission ◽  
Low Cost ◽  
Host Choice ◽  
Epidemiological Models ◽  
Choice Behaviour ◽  
Vector Borne ◽  
Transmission Models ◽  
Blood Meals

Abstract Background Mosquito-borne diseases are a global health problem, causing hundreds of thousands of deaths per year. Pathogens are transmitted by mosquitoes feeding on the blood of an infected host and then feeding on a new host. Monitoring mosquito host-choice behaviour can help in many aspects of vector-borne disease control. Currently, it is possible to determine the host species and an individual human host from the blood meal of a mosquito by using genotyping to match the blood profile of local inhabitants. Epidemiological models generally assume that mosquito biting behaviour is random; however, numerous studies have shown that certain characteristics, e.g. genetic makeup and skin microbiota, make some individuals more attractive to mosquitoes than others. Analysing blood meals and illuminating host-choice behaviour will help re-evaluate and optimise disease transmission models. Methods We describe a new blood meal assay that identifies the sex of the person that a mosquito has bitten. The amelogenin locus (AMEL), a sex marker located on both X and Y chromosomes, was amplified by polymerase chain reaction in DNA extracted from blood-fed Aedes aegypti and Anopheles coluzzii. Results AMEL could be successfully amplified up to 24 h after a blood meal in 100% of An. coluzzii and 96.6% of Ae. aegypti, revealing the sex of humans that were fed on by individual mosquitoes. Conclusions The method described here, developed using mosquitoes fed on volunteers, can be applied to field-caught mosquitoes to determine the host species and the biological sex of human hosts on which they have blood fed. Two important vector species were tested successfully in our laboratory experiments, demonstrating the potential of this technique to improve epidemiological models of vector-borne diseases. This viable and low-cost approach has the capacity to improve our understanding of vector-borne disease transmission, specifically gender differences in exposure and attractiveness to mosquitoes. The data gathered from field studies using our method can be used to shape new transmission models and aid in the implementation of more effective and targeted vector control strategies by enabling a better understanding of the drivers of vector-host interactions.

scholarly journals Temporal and Spatial Blood Feeding Patterns of Urban Mosquitoes in the San Juan Metropolitan Area, Puerto Rico

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Matthew W. Hopken ◽  
Limarie J. Reyes-Torres ◽  
Nicole Scavo ◽  
Antoinette J. Piaggio ◽  
Zaid Abdo ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Metropolitan Area ◽  
Culex Quinquefasciatus ◽  
Urban Ecosystems ◽  
Life Cycles ◽  
Pathogen Transmission ◽  
San Juan ◽  
Vertebrate Species ◽  
Blood Meals

Urban ecosystems are a patchwork of habitats that host a broad diversity of animal species. Insects comprise a large portion of urban biodiversity which includes many pest species, including those that transmit pathogens. Mosquitoes (Diptera: Culicidae) inhabit urban environments and rely on sympatric vertebrate species to complete their life cycles, and in this process transmit pathogens to animals and humans. Given that mosquitoes feed upon vertebrates, they can also act as efficient samplers that facilitate detection of vertebrate species that utilize urban ecosystems. In this study, we analyzed DNA extracted from mosquito blood meals collected temporally in multiple neighborhoods of the San Juan Metropolitan Area, Puerto Rico to evaluate the presence of vertebrate fauna. DNA was collected from 604 individual mosquitoes that represented two common urban species, Culex quinquefasciatus (n = 586) and Aedes aegypti (n = 18). Culex quinquefasciatus fed on 17 avian taxa (81.2% of blood meals), seven mammalian taxa (17.9%), and one reptilian taxon (0.85%). Domestic chickens dominated these blood meals both temporally and spatially, and no statistically significant shift from birds to mammals was detected. Aedes aegypti blood meals were from a less diverse group, with two avian taxa (11.1%) and three mammalian taxa (88.9%) identified. The blood meals we identified provided a snapshot of the vertebrate community in the San Juan Metropolitan Area and have potential implications for vector-borne pathogen transmission.

Host use patterns ofCulicoidesspp. biting midges at a big game preserve in Florida, U.S.A., and implications for the transmission of orbiviruses

2018 ◽  
Vol 33 (1) ◽  
pp. 110-120 ◽  
Author(s):  
B. L. McGregor ◽  
T. Stenn ◽  
K. A. Sayler ◽  
E. M. Blosser ◽  
J. K. Blackburn ◽  
...  
Keyword(s):  
Host Use ◽  
Biting Midges ◽  
Use Patterns

Promising Role of Wolbachia as Anti-parasitic Drug Target and Eco-Friendly Biocontrol Agent

2019 ◽  
Vol 14 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Tooran Nayeri Chegeni ◽  
Mahdi Fakhar
Keyword(s):  
Drug Target ◽  
Biocontrol Agent ◽  
Pathogen Transmission ◽  
Parasitic Diseases ◽  
Pests And Diseases ◽  
Filarial Nematodes ◽  
Reproductive Incompatibility ◽  
Vector Borne ◽  
Potential Strategy

Background: Wolbachia is the most common endosymbiotic bacteria in insectborne parasites and it is the most common reproductive parasite in the world. Wolbachia has been found worldwide in numerous arthropod and parasite species, including insects, terrestrial isopods, spiders, mites and filarial nematodes. There is a complicated relationship between Wolbachia and its hosts and in some cases, they create a mutual relationship instead of a parasitic relationship. Some species are not able to reproduce in the absence of infection with Wolbachia. Thus, the use of existing strains of Wolbachia bacteria offers a potential strategy for the control of the population of mosquitoes and other pests and diseases. Methods: We searched ten databases and reviewed published papers regarding the role of Wolbachia as a promising drug target and emerging biological control agents of parasitic diseases between 1996 and 2017 (22 years) were considered eligible. Also, in the current study several patents (WO008652), (US7723062), and (US 0345249 A1) were reviewed. Results: Endosymbiotic Wolbachia bacteria, which are inherited from mothers, is transmitted to mosquitoes and interferes with pathogen transmission. They can change the reproduction of their host. Wolbachia is transmitted through the cytoplasm of eggs and have evolved different mechanisms for manipulating the reproduction of its hosts, including the induction of reproductive incompatibility, parthenogenesis, and feminization. The extensive effects of Wolbachia on reproduction and host fitness have made Wolbachia the issue of growing attention as a potential biocontrol agent. Conclusion: Wolbachia has opened a new window to design a costly, potent and ecofriendly drug target for effective treatment and elimination of vector-borne parasitic diseases.

Seasonal Changes of Host Use by Culiseta melanura (Diptera: Culicidae) in Central Florida

2020 ◽  
Vol 57 (5) ◽  
pp. 1627-1634 ◽  
Author(s):  
Richard G West ◽  
Derrick K Mathias ◽  
Jonathan F Day ◽  
Carolina Acevedo ◽  
Thomas R Unnasch ◽  
...  
Keyword(s):  
North America ◽  
Seasonal Changes ◽  
Eastern North America ◽  
Host Use ◽  
Central Florida ◽  
Culiseta Melanura ◽  
Equine Encephalitis Virus ◽  
Brown Anole ◽  
Single Host ◽  
Blood Meals

Abstract The mosquito Culiseta melanura (Coquillett) is the primary enzootic vector of eastern equine encephalitis virus (EEEV), a zoonotic Alphavirus endemic to eastern North America. In its northern range, Cs. melanura is considered a strict avian biter, transmitting EEEV among susceptible birds in a cycle of enzootic amplification. In its southern range, however, Cs. melanura is more general in host use, feeding heavily upon birds but also reptiles and mammals. The goal of this study was to better understand how host use of Cs. melanura changes throughout the year in Florida, where year-round EEEV transmission is observed. Mosquitoes were sampled in 2018 from nine sites across three central Florida counties. In total, 213 Cs. melanura bloodmeals were identified by PCR consisting of 39 species of birds, reptiles, and mammals. Avian bloodmeals were prominent throughout the year (range = 30–85%), and songbirds were a large portion of identified bloodmeals (37.1%). Reptiles surpassed birds only in spring (April–June), and brown anole (Anolis sagrei Duméril and Bibron, 1837 [Reptilia: Dactyloidae]) was the most commonly detected single host species (22.1% overall). Mammalian bloodmeals were mainly observed in summer, with humans being the most fed on mammal (12.7% overall). This study reveals that in southern foci of EEEV transmission, Cs. melanura host use varies throughout the year with reptiles providing the majority of blood meals in spring (51.3%), and birds are fed on more than other host groups during all other seasons (50.6–70.1%). In addition, feeding on mammals increases during summer months, which may implicate Cs. melanura in epizootic transmission in Florida.

Identifying environmental drivers of insect phenology across space and time: Culicoides in Scotland as a case study

2012 ◽  
Vol 103 (2) ◽  
pp. 155-170 ◽  
Author(s):  
K.R. Searle ◽  
A. Blackwell ◽  
D. Falconer ◽  
M. Sullivan ◽  
A. Butler ◽  
...  
Keyword(s):  
Seasonal Abundance ◽  
Environmental Drivers ◽  
Spatial And Temporal Patterns ◽  
Biting Midges ◽  
Vector Borne Diseases ◽  
Temperature And Precipitation ◽  
Vector Borne ◽  
Analytical Tools ◽  
Insect Phenology

AbstractInterpreting spatial patterns in the abundance of species over time is a fundamental cornerstone of ecological research. For many species, this type of analysis is hampered by datasets that contain a large proportion of zeros, and data that are overdispersed and spatially autocorrelated. This is particularly true for insects, for which abundance data can fluctuate from zero to many thousands in the space of weeks. Increasingly, an understanding of the ways in which environmental variation drives spatial and temporal patterns in the distribution, abundance and phenology of insects is required for management of pests and vector-borne diseases. In this study, we combine the use of smoothing techniques and generalised linear mixed models to relate environmental drivers to key phenological patterns of two species of biting midges, Culicoides pulicaris and C. impunctatus, of which C. pulicaris has been implicated in transmission of bluetongue in Europe. In so doing, we demonstrate analytical tools for linking the phenology of species with key environmental drivers, despite using a relatively small dataset containing overdispersed and zero-inflated data. We demonstrate the importance of landcover and climatic variables in determining the seasonal abundance of these two vector species, and highlight the need for more empirical data on the effects of temperature and precipitation on the life history traits of palearctic Culicoides spp. in Europe.

scholarly journals Efficient population modification gene-drive rescue system in the malaria mosquito Anopheles stephensi

2020 ◽  
Author(s):  
Adriana Adolfi ◽  
Valentino M. Gantz ◽  
Nijole Jasinskiene ◽  
Hsu-Feng Lee ◽  
Kristy Hwang ◽  
...  
Keyword(s):  
Anopheles Stephensi ◽  
Pathogen Transmission ◽  
Gene Drive ◽  
Initial Release ◽  
Genetic Technologies ◽  
Rescue System ◽  
Vector Borne ◽  
Kynurenine Hydroxylase ◽  
Drive Systems ◽  
Population Suppression

ABSTRACTThe development of Cas9/gRNA-mediated gene-drive systems has bolstered the advancement of genetic technologies for controlling vector-borne pathogen transmission. These include population suppression approaches, genetic analogs of insecticidal techniques that reduce the number of vector insects, and population modification (replacement/alteration) approaches, which interfere with competence to transmit pathogens. We developed a recoded gene-drive rescue system for population modification in the malaria vector, Anopheles stephensi, that relieves the load in females caused by integration of the drive into the kynurenine hydroxylase gene by rescuing its function. Non-functional resistant alleles are eliminated via a dominantly-acting maternal effect combined with slower-acting standard negative selection, and a functional resistant allele does not prevent drive invasion. Small cage trials show that single releases of gene-drive males robustly result in efficient population modification with ≥95% of mosquitoes carrying the drive within 5-11 generations over a range of initial release ratios.

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