scholarly journals The Rate of Digestion of, Human Blood by Certain Species of Mosquitoes

1956 ◽  
Vol 9 (1) ◽  
pp. 125 ◽  
Author(s):  
AK O’gower
Keyword(s):  
Aedes Aegypti ◽  
Human Blood ◽  
Mosquito Species ◽  
Temperature And Humidity

The rate of ciigesl;iol1 of human blood was invcsLigated at 4-hourly intorval" by tho I'reeipitin and benzidine tests for tho mosquito species .Aedes aegypti, A. concolor, A. noto8oriptu8, A. soutellaris, and Culea., fllliymis. In an enviroWllent ill which temperature and humidity w('["o oonstant and in whioh thoro were equal periods of light and darkness, the mie of digestion ranged from :11 hI' for 8CUtellm'is to ·Hl hI' for A. COil color.

A Simple PCR Assay for Discrimination of Dengue Vectors from Nsukka LGA, Nigeria

2020 ◽  
Vol 10 (1) ◽  
pp. 67-77
Author(s):  
Amos Watentena ◽  
Ikem Chris Okoye ◽  
Ikechukwu Eugene Onah ◽  
Onwude Cosmas Ogbonnaya ◽  
Emmanuel Ogudu
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Mosquito Species ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Mosquito Vector ◽  
Aedes Mosquitoes ◽  
Allele Specific ◽  
Arboviral Diseases ◽  
Dengue Vectors

Mosquitoes of Aedes species are vectors of several arboviral diseases which continue to be a major public health problem in Nigeria. This study among other things, morphologically identified Aedes mosquitoes collected from Nsukka LGA and used an allele specific PCR amplification for discrimination of dengue vectors. Larval sampling, BG-sentinel traps and modified human landing catches were used for mosquito sampling in two selected autonomous communities of Nsukka LGA (Nsukka and Obimo). A total of 124 Aedes mosquitoes consisting of five (5) different species were collected from April to June, 2019 in a cross-sectional study that covered 126 households, under 76 distinct geographical coordinates. Larvae was mainly collected from plastic containers 73% (n=224), metallic containers 14% (n=43), earthen pots 9% (n=29) and used car tyres 3% (n=9), reared to adult stage 69.35% (n=86), and all mosquitoes were identified using standard morphological keys. Five (5) Aedes mosquito species were captured; Aedes aegypti 83(66.94%), Aedes albopictus 33(26.61%), Aedes simpsoni (4.48%), Aedes luteocephalus (≤1%) and Aedes vittatus (≤1%). Nsukka autonomous community had higher species diversity than Obimo. Allele specific amplification confirmed dengue vectors, Aedes aegypti and Aedes albopictus species on a 2% agarose gel. Since the most recent re-emergence of arboviral diseases is closely associated with Aedes species, findings of this study, therefore, give further evidence about the presence of potential arboviral vectors in Nigeria and describe the role of a simple PCR in discriminating some. Further entomological studies should integrate PCR assays in mosquito vector surveillance.

scholarly journals Transmission Potential of Zika Virus by Aedes aegypti (Diptera: Culicidae) and Ae. mediovittatus (Diptera: Culicidae) Populations From Puerto Rico

2021 ◽  
Author(s):  
Rebecca A Zimler ◽  
Donald A Yee ◽  
Barry W Alto
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Zika Virus ◽  
Mosquito Species ◽  
The United States ◽  
Infection Rates ◽  
Transmission Potential ◽  
Transmission Rates ◽  
Higher Doses ◽  
Local Transmission

Abstract Recurrence of local transmission of Zika virus in Puerto Rico is a major public health risk to the United States, where mosquitoes Aedes aegypti (Linnaeus) and Aedes mediovittatus (Coquillett) are abundant. To determine the extent to which Ae. mediovittatus are capable of transmitting Zika virus and the influence of viremia, we evaluated infection and transmission in Ae. mediovittatus and Ae. aegypti from Puerto Rico using serial dilutions of infectious blood. Higher doses of infectious blood resulted in greater infection rates in both mosquitoes. Aedes aegypti females were up to twice as susceptible to infection than Ae. mediovittatus, indicating a more effective midgut infection barrier in the latter mosquito species. Aedes aegypti exhibited higher disseminated infection (40–95%) than Ae. mediovittatus (<5%), suggesting a substantial midgut escape barrier in Ae. mediovittatus. For Ae. aegypti, transmission rates were low over a range of doses of Zika virus ingested, suggesting substantial salivary gland barriers.

scholarly journals Behavioural response of mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus to synthetic pyrethroid and organophosphorus-based slow-release insecticidal paint

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sunil Dhiman ◽  
Kavita Yadav ◽  
B. N. Acharya ◽  
Raj Kumar Ahirwar ◽  
D. Sukumaran
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Anopheles Stephensi ◽  
Slow Release ◽  
Disease Risk ◽  
Mosquito Species ◽  
Escape Time ◽  
Behavioural Avoidance ◽  
Vector Mosquito ◽  
Contact Exposure

Abstract Background The direct toxicological impact of insecticides on vector mosquitoes has been well emphasized; however, behavioural responses such as excito-repellency and physical avoidance as a result of insecticide exposure have not been much studied. We have demonstrated the excito-repellency and behavioural avoidance in certain vector mosquito species on exposure to a slow-release insecticidal paint (SRIP) formulation in addition to direct toxicity. Methods A SRIP formulation developed by the Defence Research and Development Establishment, Gwalior, contains chlorpyriphos, deltamethrin and pyriproxyfen as active insecticides. Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti mosquitoes were used to study the excito-repellency response of the formulation. The experiments were performed in a specially designed dual-choice exposure and escape chamber made of transparent polymethyl methacrylate. For the experiments, the SRIP formulation was applied undiluted at a rate of 8 m2 per kg on 15 cm2 metallic surfaces. Mosquitoes were introduced into the exposure chamber, and observations of the movement of mosquitoes into the escape chamber through the exit portal were taken at 1-min intervals for up to 30 min. Results The evaluated formulation displayed strong excito-repellency against all three tested vector mosquito species. Results showed that the ET50 (escape time 50%) for Ae. aegypti, An. stephensi and Cx. quinquefasciatus was 20.9 min, 14.5 min and 17.9 min for contact exposure (CE) respectively. Altogether in CE, the escape rates were stronger in An. stephensi mosquitoes at different time intervals compared to Ae. aegypti and Cx. quinquefasciatus mosquitoes. The probit analysis revealed that the determined ET did not deviate from linearity for both non-contact exposure (NCE) and placebo exposure (PE) (χ2 ≤ 7.9; p = 1.0) for Ae. aegypti mosquitoes and for NCE (χ2 = 8.3; p = 1.0) and PE (χ2 = 1.7; p = 1.0) treatments in Cx. quinquefasciatus. Mortality (24 h) was found to be statistically higher (F = 6.4; p = 0.02) in An. stephensi for CE but did not vary for NCE (p ≥ 0.3) and PE (p = 0.6) treatments among the tested mosquito species. Survival probability response suggested that all the three tested species displayed similar survival responses for similar exposures (χ2 ≤ 2.3; p ≥ 0.1). Conclusion The study demonstrates the toxicity and strong behavioural avoidance in known vector mosquito species on exposure to an insecticide-based paint formulation. The combination of insecticides in the present formulation will broaden the overall impact spectrum for protecting users from mosquito bites. The efficacy data generated in the study provide crucial information on the effectiveness of the tested formulation and could be useful in reducing the transmission intensity and disease risk in endemic countries.

scholarly journals Chikungunya: epidemiology

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 82 ◽  
Author(s):  
Lyle R. Petersen ◽  
Ann M. Powers
Keyword(s):  
Public Health ◽  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Chikungunya Virus ◽  
Mosquito Species ◽  
Febrile Illness ◽  
Current Understanding ◽  
Global Public Health ◽  
Temperate Climates

Chikungunya virus is a mosquito-borne alphavirus that causes fever and debilitating joint pains in humans. Joint pains may last months or years. It is vectored primarily by the tropical and sub-tropical mosquito, Aedes aegypti, but is also found to be transmitted by Aedes albopictus, a mosquito species that can also be found in more temperate climates. In recent years, the virus has risen from relative obscurity to become a global public health menace affecting millions of persons throughout the tropical and sub-tropical world and, as such, has also become a frequent cause of travel-associated febrile illness. In this review, we discuss our current understanding of the biological and sociological underpinnings of its emergence and its future global outlook.

scholarly journals Effects of Alternative Blood Sources on Wolbachia Infected Aedes aegypti Females within and across Generations

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 140 ◽  
Author(s):  
Véronique Paris ◽  
Ellen Cottingham ◽  
Perran Ross ◽  
Jason Axford ◽  
Ary Hoffmann
Keyword(s):  
Aedes Aegypti ◽  
Human Blood ◽  
Mass Rearing ◽  
Egg Hatch ◽  
Mass Release ◽  
Deliberate Release ◽  
Blood Source ◽  
Wolbachia Density ◽  
Infected Line ◽  
Strong Adaptation

Wolbachia bacteria have been identified as a tool for reducing the transmission of arboviruses transmitted by Aedes aegypti. Research groups around the world are now mass rearing Wolbachia-infected Ae. aegypti for deliberate release. We investigated the fitness impact of a crucial element of mass rearing: the blood meal required by female Ae. aegypti to lay eggs. Although Ae. aegypti almost exclusively feed on human blood, it is often difficult to use human blood in disease-endemic settings. When females were fed on sheep or pig blood rather than human blood, egg hatch rates decreased in all three lines tested (uninfected, or infected by wMel, or wAlbB Wolbachia). This finding was particularly pronounced when fed on sheep blood, although fecundity was not affected. Some of these effects persisted after an additional generation on human blood. Attempts to keep populations on sheep and pig blood sources only partly succeeded, suggesting that strong adaptation is required to develop a stably infected line on an alternative blood source. There was a decrease in Wolbachia density when Ae. aegypti were fed on non-human blood sources. Density increased in lines kept for multiple generations on the alternate sources but was still reduced relative to lines kept on human blood. These findings suggest that sheep and pig blood will entail a cost when used for maintaining Wolbachia-infected Ae. aegypti. These costs should be taken into account when planning mass release programs.

scholarly journals Wolbachia strain wAu efficiently blocks arbovirus transmission in Aedes albopictus

2019 ◽  
Author(s):  
Maria Vittoria Mancini ◽  
Christie S. Herd ◽  
Thomas H. Ant ◽  
Shivan M. Murdochy ◽  
Steven P. Sinkins
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Mosquito Species ◽  
Field Trials ◽  
Asian Tiger Mosquito ◽  
Native Strain ◽  
Promising Tool ◽  
Novel Approach ◽  
Asian Tiger ◽  
Tiger Mosquito

AbstractThe global incidence of arboviral diseases transmitted by Aedes mosquitoes, including dengue, chikungunya, yellow fever, and Zika, has increased dramatically in recent decades. The release of Aedes aegypti carrying the maternally inherited symbiont Wolbachia as an intervention to control arboviruses is being trialled in several countries. However, these efforts are compromised in many endemic regions due to the co-localization of the secondary vector Aedes albopictus, the Asian tiger mosquito. Ae. albopictus has an expanding global distribution following incursions into a number of new territories. To date, only the wMel and wPip strains of Wolbachia have been reported to be transferred into and characterized in this vector. A Wolbachia strain naturally infecting Drosophila simulans, wAu, was selected for transfer into a Malaysian Ae. albopictus line to create a novel triple-strain infection. The newly generated line showed self-compatibility, moderate fitness cost and complete resistance to Zika and dengue infections.Author summaryAedes albopictus, the invasive Asian tiger mosquito, is responsible for numerous outbreaks of important viruses such as dengue and Zika in various regions of the world. The need for alterative control interventions propelled the development of a novel approach that exploits a natural insect symbiont, Wolbachia; when transferred into non-native hosts, these maternally-inherited bacteria are able to interfere with the transmission of mosquito-borne viruses, and also provide reproductive advantages to the host, offering a promising tool for self-sustaining field applications. Currently, several field trials are ongoing for the primary vector of dengue and several other arboviruses, Aedes aegypti, providing encouraging results. In this study, Ae. albopictus has been targeted for a similar approach: this mosquito species naturally carries two strains of Wolbachia. The artificial introduction of a third, non-native strain made this line less able to transmit dengue and Zika viruses and had an impact on its fitness.

scholarly journals THE USE OF AGENTS BASED ON THE BACTERIUM BACILLUS THURINGIENSIS VAR. ISRAELENSIS FOR MOSQUITO CONTROL

2019 ◽  
Vol 98 (8) ◽  
pp. 893-896
Author(s):  
Svetlana A. Roslavtseva
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Synergistic Effect ◽  
Mosquito Control ◽  
Mosquito Species ◽  
Bacillus Sphaericus ◽  
Development Of Resistance ◽  
Blood Sucking ◽  
Low Concentrations ◽  
Bacterium Bacillus

Mosquito control is necessary to improve the epidemic and, consequently, the sanitary and hygienic situation in human settlements. At the same time, the safest and more environmentally friendly way of controlling is not the fight against adult mosquitoes, but the treatment of reservoirs with microbiological larvicides based on entomopathogenic, aerobic, spore-forming, saprophytic bacteria Bacillus thuringiensis (de Barjac) (Bti). A new serotype of the bacterium B. thuringiensis was found in Israel in the Negev desert. This serotype being more active against larvae of blood-sucking and non-blood-sucking mosquitoes and midges than previously known serotypes, was named israelensis. Bti endotoxin is a typical insecticide with intestinal type of action for different mosquito species. For example, Bti H14 is highly insecticidal to the larvae of Aedes aegypti and Ae. albopictus at very low concentrations. The parasporal body (endotoxin crystal), a crystalline protein consisted of four main polypeptides and two minor polypeptides, possesses of a larvicidal action. Larvicidal activity is associated with a synergistic effect in a combination of four polypeptides. The possibility of development of resistance to products based on Bti and Bacillus sphaericus in populations of mosquitoes (Culicidae) was investigated. The use of domestic microbiological formulations based on Bti («Baktitsid», «Larviol-pasta», and «Antinat») was shown an eradication the larvae of bloodsucking mosquitoes and midges to be possible and rational, since they are not generated resistant populations of mosquitoes. This is confirmed by more than 30 years of the use of such formulations.

scholarly journals Plant Natural Products for the Control of Aedes aegypti: The Main Vector of Important Arboviruses

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3484 ◽  
Author(s):  
Maíra Rosato Silveiral Silvério ◽  
Laila Salmen Espindola ◽  
Norberto Peporine Lopes ◽  
Paulo Cézar Vieira
Keyword(s):  
Natural Products ◽  
Secondary Metabolites ◽  
Aedes Aegypti ◽  
Vector Control ◽  
Chemical Constituents ◽  
Mosquito Species ◽  
Mechanisms Of Action ◽  
Control Applications ◽  
Lower Toxicity ◽  
Plant Natural Products

The mosquito species Aedes aegypti is one of the main vectors of arboviruses, including dengue, Zika and chikungunya. Considering the deficiency or absence of vaccines to prevent these diseases, vector control remains an important strategy. The use of plant natural product-based insecticides constitutes an alternative to chemical insecticides as they are degraded more easily and are less harmful to the environment, not to mention their lower toxicity to non-target insects. This review details plant species and their secondary metabolites that have demonstrated insecticidal properties (ovicidal, larvicidal, pupicidal, adulticidal, repellent and ovipositional effects) against the mosquito, together with their mechanisms of action. In particular, essential oils and some of their chemical constituents such as terpenoids and phenylpropanoids offer distinct advantages. Thiophenes, amides and alkaloids also possess high larvicidal and adulticidal activities, adding to the wealth of plant natural products with potential in vector control applications.

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