scholarly journals Comparison of the temporal efficacy of Aquatain surface films for the control of Anopheles arabiensis and Ochlerotatus caspius larvae from Sudan

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Alaa Mahmoud Ali Almalik ◽  
R. Guy Reeves ◽  
Rasha Siddig Azrag
Keyword(s):  
Anopheles Arabiensis ◽  
Anopheles Stephensi ◽  
Mosquito Species ◽  
Surface Films ◽  
Large Species ◽  
Monomolecular Film ◽  
Monomolecular Films ◽  
Lethal Time ◽  
Species Specific ◽  
Arbovirus Diseases

Aquatain mosquito formulation (AMF) is a surfactant that spreads across the surface of water bodies to produce a monomolecular film. This study experimentally evaluates the temporal efficacy of AMF against aquatic stages of Anopheles arabiensis and Ochlerotatus caspius under laboratory conditions. Using the recommended application dose of 1 ml m −2 , a large species-specific difference in the median lethal time for L3–L4 larvae was observed. The median lethal time to 50% mortality (LT50) and 90% mortality (LT90) was 1.3 h, 95% CI [1.2, 1.4] and 3.8 h, 95% CI [3.6, 4.0], respectively, for Oc. caspius . The corresponding values for An. arabiensis were 8.1 h, 95% CI [7.3, 9.0] and 59.6 h, 95% CI [48.5, 76.2]. Based on data from published laboratory studies for a total of seven mosquito species, drawn from four genera, results in the following three groups, [LT50 = 1–2 h, Culex quinquefasciatus , Ochlerotatus caspius ] [LT50 = 8–24, hours, Anopheles minimus , Anopheles arabiensis, Anopheles gambiae s.s.] and [LT50 = 72–143 h, Anopheles stephensi , Aedes aegypti ]. In all experiments, 100% mortality was achieved given sufficient time. The potential relevance of mortality rate estimates, in the context of other studies, on the use of monomolecular films for the control of malaria and arbovirus diseases is discussed.

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.

Sampling Anopheles arabiensis, A. gambiae sensu lato and A. funestus (Diptera: Culicidae) with CDC light-traps near a rice irrigation area and a sugarcane belt in western Kenya

1994 ◽  
Vol 84 (3) ◽  
pp. 319-324 ◽  
Author(s):  
A.K. Githeko ◽  
M.W. Service ◽  
C.M. Mbogo ◽  
F.A. Atieli ◽  
F.O. Juma
Keyword(s):  
Anopheles Arabiensis ◽  
Communicable Disease ◽  
Light Trap ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Light Traps ◽  
Western Kenya ◽  
Specific Variation ◽  
Species Specific ◽  
Center Light

AbstractCDC (Communicable Disease Center) light-traps were compared with human-bait collections as an alternative method for sampling malaria vectors in two villages of western Kenya. The numbers of Anopheles funestus Giles and Anopheles gambiae sensu lato Giles in CDC light-trap collections were significantly correlated to the numbers caught in human-bait collections, but in Anopheles arabiensis Patton the two collections were not significantly correlated. Most of the female vectors collected in the traps were unfed. Parity of A. arabiensis collected in CDC light-traps (44.3%) was significantly lower than the rate obtained from females caught on human-bait (54.5%). Although CDC light-traps provide a cheap and convenient method for collecting vectors, further studies should nevertheless be undertaken to determine the influence of species-specific variation in the sizes and age-structure of collections because such variations can affect the epidemiological interpretation of the data.

Larvicidal potential of selected indigenous lichens against three mosquito species–Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi

2018 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Syed Zameer Ahmed Khader ◽  
Sidhra Syed Zameer Ahmed ◽  
Kisore Perundurai Venkatesh ◽  
Kamaraj Chinnaperumal ◽  
Sanjeeva Nayaka
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Anopheles Stephensi ◽  
Mosquito Species

Dynamics of immature stages of Anopheles arabiensis and other mosquito species (Diptera: Culicidae) in relation to rice cropping in a rice agro-ecosystem in Kenya

2006 ◽  
Vol 31 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Joseph Mwangangi ◽  
Josephat Shililu ◽  
Ephantus Muturi ◽  
Weidong Gu ◽  
Charles Mbogo ◽  
...  
Keyword(s):  
Anopheles Arabiensis ◽  
Mosquito Species ◽  
Immature Stages

scholarly journals The structure of surface films. Part XVIII. ─The effect of alkalinity in the underlying solution on films of fatty acids

1933 ◽  
Vol 142 (847) ◽  
pp. 401-415 ◽  
Keyword(s):  
Fatty Acids ◽  
Acid Solution ◽  
Aqueous Solutions ◽  
Complete Solution ◽  
Alkaline Solutions ◽  
Carboxyl Group ◽  
Surface Films ◽  
Electrolytic Dissociation ◽  
End Groups ◽  
Monomolecular Films

Historical . It has been known for some time that extensive changes occur in monomolecular films of fatty acids on aqueous solutions, as the alkalinity or acidity is varied. These changes are of at least tow kinds; changes in the packing of the molecules in the coherent types of film, and changes in the lateral adhesion between molecules have already been described. Thus Adam found changes in the packing of the molecules in the condensed films on changing from neutral to acid solution; and also a change from condensed to gaseous or vapour expanded films, on changing from natural to strongly alkaline solutions. The second of those effects was considered to be due to a decrease in the lateral adhesion between the molecules, caused by the development of similar electric charges on the end groups, through electrolytic dissociation of the carboxyl group on alkaline solutions. On alkaline solutions, it has previously been noted that the films contract spontaneously; Adam called this "solution," but did not examine it in detail; Lyons and Rideal believed it to be not a complete solution, but the formation of a bimolecular layer two molecules thick; Zocher and Stiebel, by ultramicroscopic examintion, concluded that this disappearance of the film was due to a partial collapse into thick, localized aggregates, not into a uniform bimolecular film.

scholarly journals Rapid ageing and species identification of natural mosquitoes for malaria surveillance

2020 ◽  
Author(s):  
Doreen J. Siria ◽  
Roger Sanou ◽  
Joshua Mitton ◽  
Emmanuel P. Mwanga ◽  
Abdoulaye Niang ◽  
...  
Keyword(s):  
Mosquito Species ◽  
Natural Populations ◽  
Cost Effective ◽  
Malaria Vectors ◽  
Sampling Effort ◽  
Malaria Surveillance ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Species Specific ◽  
The Impact

AbstractThe malaria parasite, which is transmitted by several Anopheles mosquito species, requires more time to reach its human-transmissible stage than the average lifespan of a mosquito. Monitoring the species-specific age structure of mosquito populations is critical to evaluating the impact of vector control interventions on malaria risk. We developed a rapid, cost-effective surveillance method based on deep learning of mid-infrared spectra of mosquitoes’ cuticle that simultaneously identifies the species and the age of three main malaria vectors, in natural populations. Using over 40,000 ecologically and genetically diverse females, we could speciate and age grade An. gambiae, An. arabiensis, and An. coluzzii with up to 95% accuracy. Further, our model learned the age of new populations with minimal sampling effort and detected the impact of control interventions on simulated mosquito populations, measured as a shift in their age structures. We anticipate our method to be applied to other arthropod vector-borne diseases.

scholarly journals Anopheles gambiae and Anopheles arabiensis population densities and infectivity in Kopere village, Western Kenya

2012 ◽  
Vol 6 (08) ◽  
pp. 637-643 ◽  
Author(s):  
Andrew Ambogo Obala ◽  
Helen L Kutima ◽  
Henry D.N. Nyamogoba ◽  
Anne W Mwangi ◽  
Chrispinus J Simiyu ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Malaria Vector ◽  
Anopheles Arabiensis ◽  
Mosquito Species ◽  
Sensu Stricto ◽  
Malaria Vector Control ◽  
Insecticide Treated Nets ◽  
Western Kenya ◽  
Endemic Malaria ◽  
Vector Mosquito

Introduction: This study was conducted in a sugar belt region of western Kenya interfacing epidemic and endemic malaria transmission. We investigated Anopheles gambiae sensu stricto (ss) and Anopheles arabiensis species compositions and densities, human host choice, and infectivity. Methodology: Mosquitoes were captured using pyrethrum spray catch technique and first identified based on morphology; species were confirmed by PCR. Blood meal preference and sporozoite rates were determined by ELISA. Parity rates and entomological inoculation rates (EIR) were determined. Seasonal densities were compared against environmental temperatures, relative humidity and rainfall. Results: In total 2,426 An. gambiae were collected.  Out of 1,687 female blood-fed mosquitoes, 272 were randomly selected for entomological tests. An. gambiae ss and An. arabiensis comprised 75% (205/272) and 25% (68/272) of the selection, respectively. An. gambiae ss had higher preference for human blood (97%; n=263/272) compared with An. arabiensis, which mostly fed on bovines (88%; n=239/272).  The sporozoite and parity rates were 6% (16/272) and 66% (179/272) for An. gambiae ss and 2% (4/272) and 53% (144/272) for An. arabiensis respectively, while EIR was 0.78 infective bites/person/night.  Climate (ANOVA; F=14.2; DF=23) and temperature alone (r=0.626; t=3.75; p=0.001) were significantly correlated with vector densities. Conclusion: An. gambiae ss are the most efficient malaria vector mosquito species in Kopere village. Because An. gambiae ss largely rests and feeds indoors, use of indoor residual spray and insecticide-treated nets is likely the most suitable approach to malaria vector control in Kopere village and other parts of Kenya where this species is abundant. 

scholarly journals Mosquito species and age influence thermal performance of traits relevant to malaria transmission

2019 ◽  
Author(s):  
KL Miazgowicz ◽  
EA Mordecai ◽  
SJ Ryan ◽  
RJ Hall ◽  
J Owen ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Egg Production ◽  
Life History Traits ◽  
Anopheles Stephensi ◽  
Mosquito Species ◽  
Urban Malaria ◽  
Temperature Dependent ◽  
Biting Rate ◽  
Transmission Models ◽  
Target Intervention

AbstractModels predicting disease transmission are a vital tool in the control of mosquito populations and malaria reduction as they can target intervention efforts. We compared the performance of temperature-dependent transmission models when mosquito life history traits were allowed to change across the lifespan of Anopheles stephensi, the urban malaria mosquito, to models parameterized with commonly derived estimates of lifetime trait values. We conducted an experiment on adult female An. stephensi to generate daily per capita values for lifespan, egg production, and biting rate at six constant temperatures. Both temperature and age significantly affected trait values. Further, we found quantitative and qualitative differences between temperature-trait relationships estimated based on daily rates versus directly observed lifetime values. Incorporating these temperature-trait relationships into an expression governing transmission suitability, relative R0(T), model resulted in minor differences in the breadth of suitable temperatures for Plasmodium falciparum transmission between the two models constructed from only An. stephensi trait data, but a substantial increase in breadth compared to a previously published model consisting of trait data from multiple mosquito species. Overall this work highlights the importance of considering how mosquito trait values vary with mosquito age and mosquito species when generating temperature-based environmental suitability predictions of transmission.

scholarly journals Using mobile phones as acoustic sensors for high-throughput mosquito surveillance

2017 ◽  
Author(s):  
Haripriya Mukundarajan ◽  
Felix J H Hol ◽  
Erica A Castillo ◽  
Cooper Newby ◽  
Manu Prakash
Keyword(s):  
Mobile Phones ◽  
Large Scale ◽  
Low Cost ◽  
Mosquito Species ◽  
Mobile Network ◽  
Control Measures ◽  
New Paradigm ◽  
Mosquito Surveillance ◽  
Wide Range ◽  
Species Specific

AbstractThe direct monitoring of mosquito populations in field settings is a crucial input for shaping appropriate and timely control measures for mosquito-borne diseases. Here, we demonstrate that commercially available mobile phones are a powerful tool for acoustically mapping mosquito species distributions worldwide. We show that even low-cost mobile phones with very basic functionality are capable of sensitively acquiring acoustic data on species-specific mosquito wingbeat sounds, while simultaneously recording the time and location of the human-mosquito encounter. We survey a wide range of medically important mosquito species, to quantitatively demonstrate how acoustic recordings supported by spatio-temporal metadata enable rapid, non-invasive species identification. As proof-of-concept, we carry out field demonstrations where minimally-trained users map local mosquitoes using their personal phones. Thus, we establish a new paradigm for mosquito surveillance that takes advantage of the existing global mobile network infrastructure, to enable continuous and large-scale data acquisition in resource-constrained areas.

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