scholarly journals How long is long enough? Decreasing on plant extract lethal effects, over time, affecting Aedes aegypti larval mortality

2019 ◽  
Author(s):  
Gilberto Dinis Cozzer ◽  
Renan de Souza Rezende ◽  
Junir Antônio Lutinski ◽  
Walter Antônio Roman Junior ◽  
Maria Assunta Busato ◽  
...  

AbstractThe mosquito Aedes aegypti has overcome all kinds of human being mosquito control attempts over the last century. Strategies for vector population control resorts to the use of synthetic insecticides, which can lead to problems of intoxication in humans and environmental contamination. We evaluated the effects of Bacillus thuringiensis var. israelensis (Bti), Ilex paraguariensis (mate-herb) and Ilex theezans (caúna-herb) extracts against A. aegypti larvae mortality. The bioassays were conducted under controlled laboratory conditions of temperature (27±3°C) and photoperiod (12h). Hydroalcoholic I. theezans leaves extract displayed better residual effect compared to I. paraguariensis fruit aqueous extract. Variation in larval mortality was also observed in the exposure periods (low after a few weeks). Low mortality after a few weeks may mean increased the food for mosquito in a oppose effect over time. The residual effect of Bti was observed during the 56 days of the study duration (100% of mortality). The strongest residual effect of I. theezans was probably due to the presence of chemical on its leaves, such coumarins, hemolytic saponins and cyanogenic glucosides, absent in I. paraguariensis. On the other hand, alternative methods to vector control present risks in a long term scale by reversal of larvicide effect into food resource. Our results contributed to the prospection of natural insecticides and open the possibility for subsequent studies of the use of plant extracts in field situations in a short time scale.

2021 ◽  
Vol 56 (2) ◽  
pp. 338-345
Author(s):  
Gilberto Dinis Cozzer ◽  
Renan de Souza Rezende ◽  
Junir Antônio Lutinski ◽  
Walter Antônio Roman ◽  
Maria Assunta Busato ◽  
...  

Aedes aegypti has overcome all kinds of mosquito control attempts over the last century. Strategies for population control resorts to the use of synthetic insecticides, which can lead to problems like human intoxication and environmental contamination. The effects of Bacillus thuringiensis var. israelensis (Bti), Ilex paraguariensis (yerba mate), and Ilex theezans (caúna herb) extracts against A. aegypti larvae were evaluated. The bioassays were conducted under controlled laboratory conditions of temperature (27 ± 3°C) and photoperiod (12 h). Hydroalcoholic extract of the leaves of I. theezans displayed better residual effect compared to the aqueous extract of I. paraguariensis fruits. The strongest residual effect of I. theezans was probably due to the presence of certain chemicals in its leaves, such as coumarins, hemolytic saponins, and cyanogenic glucosides, which were absent in I. paraguariensis. The results herein contributed to the prospection of natural insecticides and opened the possibility for subsequent studies on the use of plant extracts in field situations in a short-time scale.


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 ◽  
...  

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.


2021 ◽  
Vol 37 (4) ◽  
pp. 271-279
Author(s):  
Heidi L. Murray ◽  
Catherine A. Pruszynski ◽  
Lawrence J. Hribar

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 >90%. The field trial demonstrated sufficient efficacy to introduce this method of larviciding into operational use.


2019 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Makkiah Makkiah ◽  
Cristina L Salaki ◽  
Berty Assa

Efektivitas Ekstrak Serai Wangi (Cimbopogon nardus L.) sebagai Larvasida Nyamuk Aedes aegypti (The Effectiveness of Citronella Extract (Cymbopogon nardus) as Larvaside of Aedes aegypti) Makkiah*), Cristina L Salaki **), Berty AssaProgram Studi Entomologi Pascasarjana Universitas Sam RatulangiManado, 95155*Email: [email protected],**Email korespondensi: [email protected]  (Article History: Received 20-10-2019; Revised 27-11-2019; Accepted 30-12-2019) Abstrak Pengendalian nyamuk sebagai vektor utama penularan penyakit DBD hanya dapat dilakukkan dengan cara memutuskan rantai penularannya melalui pengendalian nyamuk. Pengendalian nyamuk dapat dilakukan pada tahap larva dengan menggunakan biolarvasida yang terbuat dari bahan alami dan salah satunya adalah dengan menggunakan ekstrak kasar dari tanaman serai wangi (Cymbopogon nardus). Penelitian ini bertujuan untuk menguji efektivitas ekstrak serai wangi sebagai larvasida larva Aedes aegypti instar III dan IV. Penelitian ini adalah penelitian eksperimental menggunakan rancangan acak lengkap. Larva yang digunakan adalah larva instar III dan IV, dengan  perlakuan konsentrasi ekstrak serai wangi 20%, 30%, 40%, dan 50% dalam 250 ml air. Pada penelitian ini terdapat kontrol yaitu aquades yang tidak ditambahkan larutan apapun. Pengamatan kematian larva dilakukan pada jam ke 1, 3, 6, 12, 24, dan jam ke 48 dengan replikasi sebanyak 4 kali. Data presentase mortalitas larva digunakan untuk menghitung nilai LC50 dan LT50 dengan menggunakan analisisi Probit. Hasil penelitian menunjukkan ekstrak serai wangi efektif dalam mematikan 50% dari populasi  larva uji  dengan  nilai LC50 pada konsentrasi 36,48%serta waktu yang di butuhkan untuk mematikan  50% populasi larva uji adalah 10,45 jam. Kata kunci : Ekstrak, Cymbopogon nardus, larvasida, Aedes aegypti Abstract Control of mosquitoes as the main vector of transmission of DHF can only be done by breaking the chain of transmission through mosquito control. Mosquito control can be carried out at the larval stage by using biolarvasides made from natural materials, one of which is by using a crude extract from the citronella plant (Cymbopogon nardus). This research is to find out the effectiveness of citronella extract as larvae of Aedes aegypti larvae instar III and IV. This research is a pure experimental study using a complete random design. The larvae used were instar larvae III and IV, with the treatment of citronella extract concentration of 20%, 30%, 40%, and 50% in 250 ml of water. In this study, there was a control i.e. aquades which did not add any solution. Observation of larvae death was done at 1 hour, 2 hours. 4 hours, 12 hours, 24 hours and 28 hours with replication 4 times. Data on larval mortality were used to calculate LC50 and LT 50 values using Probit regression analysis. The results showed that citronella extract was effective in killing 50% of the population of test larvae with LC50 values at a concentration of 36.48% and the time needed to kill 50% of the population of test larvae was 10,450 hours.Key words:  Extract, Cymbopogon nardus, larvasida, Aedes aegypti


2019 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Makkiah Makkiah ◽  
Christina L Salaki ◽  
Berty Assa

Efektivitas Ekstrak Serai Wangi (Cimbopogon nardus L.) sebagai Larvasida Nyamuk Aedes aegypti (The Effectiveness of Citronella Extract (Cymbopogon nardus) as Larvaside of Aedes aegypti) Makkiah*), Christina L Salaki **), Berty AssaProgram Studi Entomologi Pascasarjana Universitas Sam RatulangiManado, 95155*Email: [email protected],**Email korespondensi: [email protected]  (Article History: Received 20-10-2019; Revised 27-11-2019; Accepted 30-12-2019) AbstrakPengendalian nyamuk sebagai vektor utama penularan penyakit DBD hanya dapat dilakukan dengan cara memutuskan rantai penularannya melalui pengendalian nyamuk. Pengendalian nyamuk dapat dilakukan pada tahap larva dengan menggunakan biolarvasida yang terbuat dari bahan alami dan salah satunya adalah dengan menggunakan ekstrak kasar dari tanaman serai wangi (Cymbopogon nardus). Penelitian ini bertujuan untuk menguji efektivitas ekstrak serai wangi sebagai larvasida larva Aedes aegypti instar III dan IV. Penelitian ini adalah penelitian eksperimental menggunakan rancangan acak lengkap. Larva yang digunakan adalah larva instar III dan IV, dengan  perlakuan konsentrasi ekstrak serai wangi 20%, 30%, 40%, dan 50% dalam 250 ml air. Pada penelitian ini terdapat kontrol yaitu aquades yang tidak ditambahkan larutan apapun. Pengamatan kematian larva dilakukan pada jam ke 1, 3, 6, 12, 24, dan jam ke 48 dengan replikasi sebanyak 4 kali. Data presentase mortalitas larva digunakan untuk menghitung nilai LC50 dan LT50 dengan menggunakan analisisi Probit. Hasil penelitian menunjukkan ekstrak serai wangi efektif dalam mematikan 50% dari populasi  larva uji  dengan  nilai LC50 pada konsentrasi 36,48%serta waktu yang di butuhkan untuk mematikan  50% populasi larva uji adalah 10,45 jam. Kata kunci : Ekstrak, Cymbopogon nardus, larvasida, Aedes aegypti AbstractControl of mosquitoes as the main vector of transmission of DHF can only be done by breaking the chain of transmission through mosquito control. Mosquito control can be carried out at the larval stage by using biolarvasides made from natural materials, one of which is by using a crude extract from the citronella plant (Cymbopogon nardus). This research is to find out the effectiveness of citronella extract as larvae of Aedes aegypti larvae instar III and IV. This research is a pure experimental study using a complete random design. The larvae used were instar larvae III and IV, with the treatment of citronella extract concentration of 20%, 30%, 40%, and 50% in 250 ml of water. In this study, there was a control i.e. aquades which did not add any solution. Observation of larvae death was done at 1 hour, 2 hours. 4 hours, 12 hours, 24 hours and 28 hours with replication 4 times. Data on larval mortality were used to calculate LC50 and LT 50 values using Probit regression analysis. The results showed that citronella extract was effective in killing 50% of the population of test larvae with LC50 values at a concentration of 36.48% and the time needed to kill 50% of the population of test larvae was 10,450 hours.Keywords:  Extract, Cymbopogon nardus, larvasida, Aedes aegypti


2020 ◽  
Vol 36 (1) ◽  
pp. 16-21 ◽  
Author(s):  
S. Dzib-Florez ◽  
G. Ponce-García ◽  
A. Che-Mendoza ◽  
A. Medina-Barreiro ◽  
L. Gray ◽  
...  

ABSTRACT Commercial aerosolized insecticides can be implemented as a community-based approach to targeted indoor residual spraying against Aedes aegypti, but their efficacy on pyrethroid-resistant mosquitoes has not yet been evaluated. Two commercial aerosolized products (H24 Poder Fulminante Ultra Eficaz®, carbamate, and Baygon Ultra Verde®, pyrethroid) were sprayed on common indoor surfaces e.g., cement, plywood, and cloth, and tested for their residual efficacy on susceptible and field-derived pyrethroid-resistant Ae. aegypti strains using the WHO cone bioassays. Overall, ≥80% 24-h mortality was observed for both products for at least 4 wk regardless of the mosquito strain or surface type used. H24 Poder Fulminante Ultra Eficaz showed the highest residual potency, sustaining >80% mortality for 7-wk posttreatment regardless of mosquito strain and surface type. For Baygon Ultra Verde, the mean mortality of female Ae. aegypti remained >80% for a shorter period (4–6 wk). Nonpyrethroid commercial aerosolized formulations can provide a lasting residual effect indoors compatible with the need for rapid and lasting mosquito control during outbreaks and may be suitable for community-based targeted indoor residual spraying.


2012 ◽  
Vol 44 (3) ◽  
pp. 15 ◽  
Author(s):  
Arjunan Nareshkumar ◽  
Kadarkarai Murugan ◽  
Indra Baruah ◽  
Pari Madhiyazhagan ◽  
Thiyagarajan Nataraj

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.


Author(s):  
F. B. Adewoyin ◽  
A. B. Odaibo ◽  
C. A. Elusiyan ◽  
J. M. Agbedahunsi

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.


2020 ◽  
Vol 26 (33) ◽  
pp. 4092-4111
Author(s):  
Mikael A. de Souza ◽  
Larissa da Silva ◽  
Maria A. C. dos Santos ◽  
Márcia J. F. Macêdo ◽  
Luiz J. Lacerda-Neto ◽  
...  

The Aedes aegypti is responsible for the transmission of arboviruses, which compromise public health. In the search for synthetic product alternatives, essential oils (OEs) have been highlighted by many researchers as natural insecticides. This systematic review (SR) was performed according to PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and its objective was to evaluate studies addressing OEs with larvicidal properties against Ae. aegypti, through electronic database searches (Pubmed, Science Direct and Scielo), covering an overview of the plant sources OEs, which plant parts were used, the extraction methods, analytical techniques, major and/or secondary constituents with greater percentages, as well as the LC50s responsible for larval mortality. Following study analysis, plants distributed across 32 families, 90 genera and 175 species were identified. The Lamiaceae, Myrtaceae, Piperaceae, Asteraceae, Rutaceae, Euphorbiaceae and Lauraceae families obtained the highest number of species with toxic properties against larvae from this vector. Practically all plant parts were found to be used for OE extraction. Hydrodistillation and steam distillation were the main extraction methods identified, with GC-MS/GC-FID representing the main analytical techniques used to reveal their chemical composition, especially of terpene compounds. In this context, OEs are promising alternatives for the investigation of natural, ecologically correct and biodegradable insecticides with the potential to be used in Ae. aegypti control programs.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Tse-Yu Chen ◽  
Chelsea T. Smartt ◽  
Dongyoung Shin

Aedes aegypti, as one of the vectors transmitting several arboviruses, is the main target in mosquito control programs. Permethrin is used to control mosquitoes and Aedes aegypti get exposed due to its overuse and are now resistant. The increasing percentage of permethrin resistant Aedes aegypti has become an important issue around the world and the potential influence on vectorial capacity needs to be studied. Here we selected a permethrin resistant (p-s) Aedes aegypti population from a wild Florida population and confirmed the resistance ratio to its parental population. We used allele-specific PCR genotyping of the V1016I and F1534C sites in the sodium channel gene to map mutations responsible for the resistance. Two important factors, survival rate and vector competence, that impact vectorial capacity were checked. Results indicated the p-s population had 20 times more resistance to permethrin based on LD50 compared to the parental population. In the genotyping study, the p-s population had more homozygous mutations in both mutant sites of the sodium channel gene. The p-s adults survived longer and had a higher dissemination rate for dengue virus than the parental population. These results suggest that highly permethrin resistant Aedes aegypti populations might affect the vectorial capacity, moreover, resistance increased the survival time and vector competence, which should be of concern in areas where permethrin is applied.


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