scholarly journals Larvicidal potentiality, longevity and fecundity inhibitory activities of Bacillus sphaericus (Bs G3-IV) on vector mosquitoes, Aedes aegypti and Culex quinquefasciatus

2012 ◽  
Vol 44 (3) ◽  
pp. 15 ◽  
Author(s):  
Arjunan Nareshkumar ◽  
Kadarkarai Murugan ◽  
Indra Baruah ◽  
Pari Madhiyazhagan ◽  
Thiyagarajan Nataraj
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Mosquito Control ◽  
Larval Mortality ◽  
Bacillus Sphaericus ◽  
Control Agent ◽  
Vector Borne Diseases ◽  
Vector Population ◽  
Intervention Measures ◽  
Vector Borne

Intervention measures to control the transmission of vector-borne diseases include control of the vector population. In mosquito control, synthetic insecticides used against both the larvae (larvicides) and adults (adulticides) create numerous problems, such as environmental pollution, insecticide resistance and toxic hazards to humans. In the present study, a bacterial pesticide,<em> Bacillus sphaericus</em> (Bs G3-IV), was used to control the dengue and filarial vectors, <em>Aedes aegypti</em> and <em>Culex quinquefasciatus</em>. <em>Bacillus sphaericus </em>(Bs G3-IV) was very effective against<em> Aedes aegypti</em> and <em>Culex quinquefasciatus</em>, showing significant larval mortality. Evaluated lethal concentrations (LC<sub>50</sub> and LC<sub>90</sub>) were age-dependent, with early instars requiring a lower concentration compared with later stages of mosquitoes. <em>Culex quinquefasciatus</em> was more susceptible to <em>Bacillus sphaericus</em> (Bs G3-IV) than was <em>Aedes aegypti</em>. Fecundity rate was highly reduced after treatment with different concentrations of <em>Bacillus sphaericus</em> (Bs G3-IV). Larval and pupal longevity both decreased after treatment with <em>Bacillus sphaericus</em> (Bs G3-IV), total number of days was lower in the <em>B. sphaericus</em> treatments compared with the control. Our results show the bacterial pesticide <em>Bacillus sphaericus </em>(Bs G3-IV) to be an effective mosquito control agent that can be used for more integrated pest management programs.

scholarly journals Larvicidal Activity of Elytraria acaulis against Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae)

2020 ◽  
Author(s):  
Soorya Sukumaran ◽  
Rajan Maheswaran
Keyword(s):  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Culex Quinquefasciatus ◽  
Probit Analysis ◽  
Human Beings ◽  
Vector Borne Diseases ◽  
Blood Sucking ◽  
Leaf Powder ◽  
Vector Borne ◽  
Chemical Pesticides

Background: Mosquitoes are blood sucking arthropods and serve as vectors of many diseases causing serious health problems to human beings. Culex quinquefasciatus and Aedes aegypti were responsible for Filariasis and Dengue. Syn­thetic pesticides were effective against mosquitoes as well as main sources of environmental pollution and most of them are immunosuppressant. Botanicals were widely used as insecticides, growth disruptors, repellents, etc. The aim of this research was to determine larvicidal properties of powdered leaf, Elytraria acaulis against late third or early fourth in­star larvae of Cx. quinquefasciatus and Ae. aegypti. Methods: Larvae of Cx. quinquefasciatus and Ae. aegypti were tested at various concentrations of 100, 120, 140, 160, 180 and 200mg/100ml and mortality was recorded after 24h. The LC50 values of the E. acaulis leaf powder were calcu­lated by Probit analysis. Results: The plant powder exhibited strong larvicidal activity against Cx. quinquefasciatus with LC50 value of 116.07mg/100ml against Ae. aegypti 124.25mg/100ml respectively. The result indicated that the plant powder of E. acaulis showed potential larvicidal activity against Cx. quinquefasciatus and Ae. aegypti. Conclusion: The overall findings of the present investigation suggested that the E. acaulis highly effective against Cx. quinquefasciatus and Ae. aegypti larvae. Elytraria acaulis may be used as an alternative to synthetic chemical pesticides for control of vectors to reduce vector borne diseases and did not harm to total environment.

scholarly journals ENTOMOLOGICAL PARAMETERS AND CHARACTERIZATION OF INSECTICIDE RESISTANCE IN DENGUE VECTOR AEDES AEGYPTI LARVAE FROM BENGKULU CITY, INDONESIA

2021 ◽  
Vol 21 (1) ◽  
pp. 96-102
Author(s):  
Dessy Triana ◽  
Fitaloca N Siregar ◽  
Eka Purnama Wulan Tri Utami ◽  
Tatik Suteky ◽  
Swandito Wicaksono
Keyword(s):  
Aedes Aegypti ◽  
Cross Sectional ◽  
Vector Borne Diseases ◽  
Control Programs ◽  
Vector Population ◽  
Who 1999 Criteria ◽  
Vector Borne ◽  
Dengue Control ◽  
Breeding Place

In Bengkulu, as in other areas of Indonesia, dengue is one of the most important vector-borne diseases. The primary strategy to control dengue is by reducing the vector population using insecticides. However, applications of insecticides becomes a contributing factor in the development of vector resistance. As there is no effective dengue drug or safe vaccine available, vector control remains the most effective intervention to reduce incidence and prevent transmission and outbreak. This study aimed to determine the entomological parameters and resistance status to temephos of Aedes aegypti larvae from Lingkar Barat village and Jalan Gedang village (dengue endemic areas). This study used cross-sectional and experimental with post-control only design. The sampling refers to the guidelines for dengue entomology surveys according to WHO 1999 criteria. Aedes aegypti eggs were collected by ovitraps and reared to larvae stage. Susceptibility test of larvae to the temephos was estimated using standard WHO. Mortality of larvae Ae. aegypti after 24 hours with multiple concentration of temephos indicative of highly resistant.  Entomological parameters for house index (HI), container index (CI) and container pupa index (CPI) in Jalan Gedang village and Lingkar Barat village were estimated: 7%, 12% for HI and 1.97%, 3.43% for CI, and 5%, 2% for CPI, respectively. The proportion of controllable sites is higher than disposable sites, it has a high risk as breeding places for mosquitoes indicates a high potential risk as breeding place and transmission of dengue. Awareness sanitation in the home and surrounding environment must be possessed by each individual community in order to prevent and overcome the incidence of dengue. These data should be of value in formulating dengue control programs.

Assessment of Resistance to Organophosphates and Pyrethroids in Aedes aegypti (Diptera: Culicidae): Do Synergists Affect Mortality?

2020 ◽  
Vol 57 (6) ◽  
pp. 1992-1996
Author(s):  
Natalie P Cataldo ◽  
C Suzanne Lea ◽  
Timothy Kelley ◽  
Stephanie L Richards
Keyword(s):  
Aedes Aegypti ◽  
Yellow Fever ◽  
Mosquito Control ◽  
Control Measures ◽  
Diethyl Maleate ◽  
Vector Borne Diseases ◽  
Diagnostic Time ◽  
Primary Vector ◽  
Vector Borne ◽  
Tributyl Phosphorotrithioate

Abstract Aedes aegypti (L.) is the primary vector of Zika, dengue, yellow fever, and chikungunya viruses. Insecticides used in mosquito control can help prevent the spread of vector-borne diseases. However, it is essential to determine insecticide resistance (IR) status before control measures are undertaken. Only the most effective insecticides should be used to avoid ineffective control and/or promotion of IR. Pyrethroids and organophosphates are the most commonly used insecticides for mosquito control. Here, the efficacy of two active ingredients (AIs; permethrin [pyrethroid], chlorpyrifos [organophosphate]), two formulated products (FPs; Biomist [AI: permethrin]) and (Mosquitomist [AI: chlorpyrifos]), and three synergists (piperonyl butoxide, diethyl maleate, S-S-S-tributyl phosphorotrithioate) was evaluated in two Ae. aegypti colonies (pyrethroid resistant and susceptible). Mosquitomist was most effective against the pyrethroid-resistant colony (100% mortality at diagnostic time). Pre-exposure to synergists did not increase the efficacy of AIs against the pyrethroid-resistant colony. Further research is needed to discover how synergists may affect the efficacy of insecticides when used on pyrethroid-resistant mosquitoes.

scholarly journals Insecticidal Activities of Leaf Methanol Extract of Clerodendrum polycephalum Baker against Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus

2021 ◽  
pp. 7-14
Author(s):  
F. B. Adewoyin ◽  
A. B. Odaibo ◽  
C. A. Elusiyan ◽  
J. M. Agbedahunsi
Keyword(s):  
Aedes Aegypti ◽  
Anopheles Gambiae ◽  
Culex Quinquefasciatus ◽  
Crude Extract ◽  
Methanol Extract ◽  
Mosquito Control ◽  
Larval Mortality ◽  
Control Programme ◽  
Filter Papers ◽  
Insecticidal Activities

Aim: In a view to determining the capacity of Clerodendrum polycephalum to control mosquitoes, the methanol extract of the leaf was investigated for insecticidal activities using three species of mosquitoes, Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Methodology: The leaves of C. polycephalum were collected, dried and extracted with methanol.   Mosquito larvae were exposed to different concentrations for 24/48h. and sublethal concentrations (L25, 50, 75) of the extract to determine larvicidal activity and monitor growth and development respectively. Twenty (20) blood-fed female Aedes aegyti mosquitoes were allowed to lay eggs on treated filter papers for antioviposition bioassay. The crude extract was separated into N-hexane, Dichloromethane, ethyl-acetate, ethanol fractions using Vacuum Liquid Chromatography to determine the active fraction. Results: Results showed that larval mortalities were in the order C. quiquefasciatus>A. gambiae>A. aegypti with effective concentration ranging from 250 – 8000 ppm. Mortalities at 48hr were significantly different (p<0.05) from mortalities at 24h. Of the four fractions obtained, ethanol fraction gave the highest larval mortality of 100% at 2000 ppm. Larval duration for all the three species of mosquitoes exposed to the crude extract varied between 2.25±0.5 and 3.25±0.5 days. As Antioviposition Index increased from 46.4 - 89.9, percent hatching of mosquito eggs deceased from 87.25 – 67.5% with increasing concentration. Conclusion: The extract of C. polycephalum was found to contain insecticidal compounds which are soluble in polar solvent. The plant could be exploited in mosquito control programme.

Comparison of the Effect of Insecticides on Bumble Bees (Bombus impatiens) and Mosquitoes (Aedes aegypti and Culex quinquefasciatus) by Standard Mosquito Research Methods

2020 ◽  
Author(s):  
Bethany L McGregor ◽  
Bryan V Giordano ◽  
Alfred E Runkel ◽  
Herbert N Nigg ◽  
H Lee Nigg ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Mosquito Control ◽  
The United States ◽  
Field Trials ◽  
Bombus Impatiens ◽  
Acute Effects ◽  
Nontarget Effects ◽  
Native North American ◽  
Significant Mortality

Abstract Mosquito control districts in the United States are limited to two main classes of adulticides, pyrethroids and organophosphates, to control mosquitoes. Two adulticides used to control domestic mosquitoes are Fyfanon EW (malathion, organophosphate) and DeltaGard (deltamethrin, pyrethroid). While the effect of these pesticides on European honeybees (Apis mellifera L., Hymenoptera: Apidae) has been investigated, effects on native pollinators need additional research. The purpose of this study was to investigate the acute nontarget effects of these pesticides on Bombus impatiens Cresson (Hymenoptera: Apidae), a native North American bumble bee species, and compare these effects to wild and laboratory strains of mosquitoes (Aedes aegypti (L.) and Culex quinquefasciatus Say, Diptera: Culicidae) through field and laboratory assays. Bombus impatiens was found to be resistant to Fyfanon EW (x̅ = 6.7% mortality at 50-µg malathion per bottle) at levels that caused significant mortality to study mosquitoes (86.2 ≥ x̅ ≥ 100% mortality) in laboratory bottle bioassays. Comparatively, B. impatiens demonstrated greater mortality to DeltaGard (93.3%) at 2.5-µg deltamethrin/bottle than any mosquito colony assayed (14.1 ≥ x̅ ≥ 87.0% mortality). Only DeltaGard was tested in field applications. In the field, we observed acute effects of DeltaGard on mosquitoes and B. impatiens at 25- and 75-m distance from a truck-mounted ultra-low volume fogger, although treatment effects were not significant for B. impatiens. Additional wild-caught nontarget mortality to DeltaGard field trials was also evaluated. This study indicated that common mosquito control adulticides do cause nontarget mortality to B. impatiens but that impacts are variable depending on pesticide and further studies are needed.

scholarly journals Larvicidal Effectiveness of Azolla pinnata against Aedes aegypti (Diptera: Culicidae) with Its Effects on Larval Morphology and Visualization of Behavioural Response

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Nor Shaida Husna Zulkrnin ◽  
Nurul Nadiah Rozhan ◽  
Nur Amanina Zulkfili ◽  
Nik Raihan Nik Yusoff ◽  
Mohd Sukhairi Mat Rasat ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Larval Mortality ◽  
Control Program ◽  
Test Method ◽  
World Health ◽  
Azolla Pinnata ◽  
Agricultural Field ◽  
Aquatic Fern ◽  
Significant Difference

Dengue is vector-borne diseases with 390 million infections per year extending over 120 countries of the world. Aedes aegypti (L.) (Diptera: Culicidae) is a primary vector for dengue viral infections for humans. Current focus on application of natural product against mosquito vectors has been the main priority for research due to its eco-safety. The extensive use of chemical insecticides has led to severe health problems, environmental pollution, toxic hazards to human and nontarget species, and development of insecticide resistance on mosquitoes. Azolla pinnata is an aquatic fern and predominantly used as feed in poultry industry and as fertilizer in agricultural field for enhancing the fertility of rice paddy soil. The present study was conducted to explore the larvicidal efficacy of A. pinnata using fresh and powdered form against late third-stage larvae (6 days, 5 mm in larvae body length) of Ae. aegypti (L.) (Diptera: Culicidae). The larvicidal bioassays were performed using World Health Organization standard larval susceptibility test method for different concentration for powdered and fresh A. pinnata. Powdered A. pinnata concentration used during larvicidal bioassay ranges from 500ppm to 2000ppm; meanwhile, fresh A. pinnata ranges from 500ppm to 9,000,000 ppm. The highest mortality was at 1853 ppm for powdered A. pinnata compared with fresh A. pinnata at 2,521,535 ppm, while the LC50 for both powdered and fresh A. pinnata recorded at 1262 ppm and 1853 ppm, respectively. Finally, the analysis of variance (ANOVA) showed significant difference on Ae. aegypti larval mortality (F=30.439, df=1, p≤0.001) and concentration (F=20.002, df=1, p≤0.001) compared to powdered and fresh A. pinnata at 24-hour bioassay test. In conclusion, the powdered A. pinnata serves as a good larvicidal agent against Ae. aegypti (L.) (Diptera: Culicidae) and this study provided information on the lethal concentration that may have potential for a more eco-friendly Aedes mosquito control program.

scholarly journals Global spatial assessment of Aedes aegypti and Culex quinquefasciatus: a scenario of Zika virus exposure

2018 ◽  
Vol 147 ◽  
Author(s):  
Alberto J. Alaniz ◽  
Mario A. Carvajal ◽  
Antonella Bacigalupo ◽  
Pedro E. Cattan
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Zika Virus ◽  
Mosquito Control ◽  
Health Planning ◽  
Risk Level ◽  
Spatially Explicit ◽  
World Population ◽  
Potential Vector ◽  
Risk Zones

AbstractZika virus (ZIKV) is an arbovirus transmitted mainly by Aedes aegypti mosquitoes. Recent scientific evidence on Culex quinquefasciatus has suggested its potential as a vector for ZIKV, which may change the current risk zones. We aimed to quantify the world population potentially exposed to ZIKV in a spatially explicit way, considering the primary vector (A. aegypti) and the potential vector (C. quinquefasciatus). Our model combined species distribution modelling of mosquito species with spatially explicit human population data to estimate ZIKV exposure risk. We estimated the potential global distribution of C. quinquefasciatus and estimated its potential interaction zones with A. aegypti. Then we evaluated the risk zones for ZIKV considering both vectors. Finally, we quantified and compared the people under risk associated with each vector by risk level, country and continent. We found that C. quinquefasciatus had a more temperate distribution until 42° in both hemispheres, while the risk involving A. aegypti is concentrated mainly in tropical latitudes until 35° in both hemispheres. Globally, 4.2 billion people are under risk associated with ZIKV. Around 2.6 billon people are under very high risk associated with C. quinquefasciatus and 1 billion people associated with A. aegypti. Several countries could be exposed to ZIKV, which emphasises the need to clarify the competence of C. quinquefasciatus as a potential vector as soon as possible. The models presented here represent a tool for risk management, public health planning, mosquito control and preventive actions, especially to focus efforts on the most affected areas.

scholarly journals Ground Applications of Vectobac® WDG with A1 Super-Duty Mist Sprayer® and Micronair® AU5000 Atomizer for Suppression of Aedes aegypti Populations in the Florida Keys

2021 ◽  
Vol 37 (4) ◽  
pp. 271-279
Author(s):  
Heidi L. Murray ◽  
Catherine A. Pruszynski ◽  
Lawrence J. Hribar
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Larval Mortality ◽  
Florida Keys ◽  
Application Rate ◽  
Residential Area ◽  
Distilled Water ◽  
Bacillus Thuringiensis Israelensis ◽  
Key West ◽  
F1 Generation

ABSTRACT Since 2011, the Florida Keys Mosquito Control District (FKMCD) has used the WALS® application strategy with VectoBac® WDG containing Bacillus thuringiensis israelensis via helicopter in Key West for the control of Aedes aegypti larval populations. In 2018, FKMCD conducted a study to determine the effectiveness of using a trailer-mounted A1 Super Duty Mist Sprayer® (A1 Mist Sprayers) with a Micronair® AU5000 (Micron Group) atomizer to apply VectoBac WDG by ground at the rate of 0.5 lb/acre (0.56 kg/ha). Bioassay cups were placed in a residential area encompassing open, moderate, and heavy cover scenarios between 0 and 300 ft (0–91.44 m) perpendicular to the spray line. An application rate of 0.5 lbs/acre (0.56 kg/ha) was used. Bioassay cups were collected after application and returned to the laboratory where 100 ml of distilled water and 10 F1 generation Ae. aegypti larvae were added. Laval mortality was monitored at 2, 4, and 24 h. Three separate runs were completed during the summer of 2018. Average larval mortality at 24 h was &gt;90%. The field trial demonstrated sufficient efficacy to introduce this method of larviciding into operational use.

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.

RNAi-Mediated Screening of Selected Target Genes Against Culex quinquefasciatus (Diptera: Culicidae)

2021 ◽  
Author(s):  
Sayed M S Khalil ◽  
Kashif Munawar ◽  
Azzam M Alahmed ◽  
Ahmed M A Mohammed
Keyword(s):  
Culex Quinquefasciatus ◽  
Target Genes ◽  
Mosquito Control ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Lethal Effect ◽  
Delivery Methods ◽  
Valley Fever ◽  
Wide Range ◽  
Lethal Genes

Abstract Culex quinquefasciatus, a member of the Culex pipiens complex, is widespread in Saudi Arabia and other parts of the world. It is a vector for lymphatic filariasis, Rift Valley fever, and West Nile virus. Studies have shown the deleterious effect of RNA interference (RNAi)-mediated knockdown of various lethal genes in model and agricultural pest insects. RNAi was proposed as a tool for mosquito control with a focus on Aedes aegypti and Anopheles gambiae. In this study, we examined the effect of RNAi of selected target genes on both larval mortality and adult emergence of Cx. quinquefasciatus through two delivery methods: soaking and nanoparticles. Ten candidate genes were selected for RNAi based on their known lethal effect in other insects. Disruption of three genes, chitin synthase-1, inhibitor of apoptosis 1, and vacuolar adenosine triphosphatase, resulted in the highest mortality among the selected genes using the two treatment methods. Silencing the other seven genes resulted in a medium to low mortality in both assays. These three genes are also active against a wide range of insects and could be used for RNAi-based mosquito control in the future.

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