Control Of Aedes Aegypti Larvae Research Articles

Analysis of Aedes Aegypti Larval Density on The Potential Transmission of Dengue Fever

Dengue hemorrhagic fever (DHF) is caused by the dengue virus transmitted through the Aedes aegypti mosquito. DHF remains a health problem in Indonesia. Based on data from the Ministry of Health, there were 184 cases of the disease in 2022, an increase of 94.8% compared to 2021, which had 73,518 cases. According to the Central Statistics Agency of South Sumatra Province, the number of DHF cases in South Sumatra was 2,854 cases, with the highest number in the city of Palembang at 908 cases. This condition requires serious attention. The aim of this study is to analyze the potential transmission of DHF based on entomological evidence in the Sukarami district of Palembang. The method used in the research is a cross-sectional study conducted in December 2023, involving 92 households in the Sukarami sub-district, with a total of 552 containers. The survey results of larval identification under a microscope showed a Larval Free Index of 45.7%, a Container Index of Aedes aegypti larvae of 56.0%, a house index of 73.9%, and a Breteau index of 152.2%. The results of entomological indices indicate a high density of DHF vector mosquitoes Aedes aegypti, which means that this area has a high risk of DHF transmission, thus requiring the control of Aedes aegypti larvae and the eradication of DHF. breeding sites for the vector.

Larvicidal effect of the essential oil of Curcuma xanthorrhiza (ginger java) for Aedes aegypti

The larvicidal effect of the essential oil nanoemulsions of Curcuma xanthorrhiza (known as ginger java) in Aedes aegypti species. For this, they were collected as plants of C. xanthorrhiza Luís, MA and, later, separated as leaves from their respective branches. The essential oil was obtained by means of hydrodistillation by dragging a steam at a temperature of 100ºC for 3 hours. The nanoemulsions were prepared using the phase inversion method. The chemical constituents were quantified and identified by Gas Chromatography Coupled with Mass Spectrometry (GC/MS). Aedes aegypti eggs were transmitted through ovit traps. As Aedes aegypti larvae, they were hatched in mineral water, identified and fed until the 4th instar. For the activity of the activity. living and dead count. A Probit statistical analysis was performed to quantify the Lethal Concentration 50% (LC50). The GC/MS quantified the major components in the essential oil, namely germacrone (25.46%), xanthorrizole (17.52%) and eucalyptol (11.92%). The larvicidal activity of the essential oil nanoemulsion for Aedes aegypti quantified an LC50 of 25.94 mg. L-1, being defined by the evaluation criterion as active in the control and combat of A. aegypti. The essential nanoemulsion of C. xanthorrhiza has efficient larvicidal activity, so there is a need for further studies of its form of operation and safety for the combat and control of Aedes aegypti larvae.

SURVEY OF AEDES AEGYPTI LARVAE ON THE PERIMETER OF THE AREA AT THE PORT OF GORONTALO CITY

The port is a meeting point where the ships, goods and people embark and disembark, also a gateway for the transformation of the spread of diseases such as dengue fever. The efforts to prevent dengue transmission at ports are to free the port area from the life of the Aedes aegypti mosquito. At the perimeter of the port area of Gorontalo, the HI and CI gures for 2011-2013 have exceeded the predetermined indicator, namely 0 and at the port, there are many buildings and containers for port activities that can become breeding grounds for larvae. The formulation of the problem in this study is how the results of the Aedes aegypti larva survey in the Perimeter Area in the Port of Gorontalo City are. The novelty of this study is due to research on surveys of Aedes Aegypti larvae around the area in the port . This study aimed to determine the HI and CI numbers and the types of potential breeding sites for Aedes aegypti larvae in the perimeter area of the port of Gorontalo city. This research was an observational study with a descriptive study approach. Where the samples studied were 25 buildings and 48 containers. The sampling technique used was total sampling. Based on the results of data analysis, it is known that the HI and CI numbers on the perimeter area in the port of Gorontalo city are HI (16%) and CI (12.5%) and the type of potential breeding place for Aedes aegypti larvae are buckets. For this reason, it is hoped that the port of Gorontalo City will close and drain the TPA and the Class III KKP of Gorontalo further to improve the control of Aedes aegypti larvae and mosquitoes.Keywords: Larvae survey; Port; Aedes aegypti

Tetradenia riparia leaves, flower buds, and stem essential oils to control of Aedes aegypti larvae

Tetradenia riparia (Hochst.) Codd (Lamiaceae) is a species native to the African continent and used as an insect repellent. The objective of the study was to evaluate the larvicidal potential of essential oils (EOs) from the leaves, flower buds, and stem of T. riparia, collected in winter against Aedes aegypti larvae. The EOs were extracted by hydrodistillation (3 h) and identified by GC/MS. The EOs were tested against larvae of A. aegypti at concentrations ranging from 12500 to 1.5 µg/mL for 24 h. The insecticide activity was evaluated by probit analysis, and the anticholinesterase activity was determined by bioautographic method. The results of the class projection indicated sesquiterpenes as the majority class, corresponding to 60.66% (leaves), 64.70% (flower buds) and 83.99% (stem), and the bioassays on A. aegypti larvae indicated LC50 of 1590, 675 and 665 µg/mL, respectively. The anticholinesterase activity indicated that the EO of the leaves inhibited the enzyme at a concentration of 780 µg/mL, and those from the flower buds and stem inhibited up to 1560 µg/mL. The results indicated weak activity of essential oils against A. aegypti larvae.

Photodynamic control of Aedes aegypti larvae with environmentally-friendly tetra-platinated porphyrin.

This work evaluated the photosensitizing activity of isomeric tetra-cationic porphyrins with peripheral [Pt(bpy)Cl]+ to control the larval population of Aedes aegypti by photodynamic action. The photolarvicidal activity of the tetra-platinated porphyrins at meta and para position (3-PtTPyP and 4-PtTPyP) was evaluated under blue (450nm), green (525nm), and red (625nm) light illumination at 55.0Jcm-2. The meta isomer presented an efficient photolarvicidal activity even at a low concentration (1.2ppm) in the presence of light, while the para counterpart was inactive regardless of the concentration and illumination. The different responses were related to the improved optical features and higher water solubility of 3-PtTPyP compared to 4-PtTPyP. Additionally, the potential environmental toxicity of 3-PtTPyP was tested in a plant model (Allium cepa test), with no toxicity detected for all used concentrations (1.2 to 12ppm). Hence, this work reveals that 3-PtTPyP has a great potential to be employed to photodynamically control the insect vector population in an environmentally safe way.

Development of nano-emulsions based on Ayapana triplinervis essential oil for the control of Aedes aegypti larvae.

Ayapana triplinervis is a plant species used in traditional medicine and in mystical-religious rituals by traditional communities in the Amazon. The aim of this study are to develop a nano-emulsion containing essential oil from A. triplinervis morphotypes, to evaluate larvicidal activity against Aedes aegypti and acute oral toxicity in Swiss albino mice (Mus musculus). The essential oils were extracted by steam dragging, identified by gas chromatography coupled to mass spectrometry, and nano-emulsions were prepared using the low energy method. Phytochemical analyses indicated the major compounds, expressed as area percentage, β-Caryophyllene (45.93%) and Thymohydroquinone Dimethyl Ether (32.93%) in morphotype A; and Thymohydroquinone Dimethyl Ether (84.53%) was found in morphotype B. Morphotype A essential oil nano-emulsion showed a particle size of 101.400 ± 0.971 nm (polydispersity index = 0.124 ± 0.009 and zeta potential = -19.300 ± 0.787 mV). Morphotype B essential oil nano-emulsion had a particle size of 104.567 ± 0.416 nm (polydispersity index = 0.168 ± 0.016 and zeta potential = -27.700 ± 1.307 mV). Histomorphological analyses showed the presence of inflammatory cells in the liver of animals treated with morphotype A essential oil nano-emulsion (MAEON) and morphotype B essential oil nano-emulsion (MBEON). Congestion and the presence of transudate with leukocyte infiltration in the lung of animals treated with MAEON were observed. The nano-emulsions containing essential oils of A. triplinervis morphotypes showed an effective nanobiotechnological product in the chemical control of A. aegypti larvae with minimal toxicological action for non-target mammals.

Bioprospecting of Bacillus thuringiensis in the control of Aedes aegypti larvae

Aedes aegypti (Diptera: Culicidae) is the main vector of Dengue, Zika and Chikungunya, diseases that have attracted the attention of scientific society and the population in general, due to epidemiological outbreaks and numerous health hazards and the imminent risk of death. Much has been discussed about more efficient forms of control for this mosquito, considering that the chemical control, currently used, has been causing impacts on the environment and the health of the population. Thus, alternative methods have been evaluated. Among them, biological control through products formulated from Bacillus thuringiensis has stood out, as biotechnological advances have allowed to improve and enhance the products already on the market, as well as to develop new bioinsecticides from the entomopathogenic proteins produced by these microorganisms, aiming to make the larvae control more and more effective. To this end, this study aimed to carry out a bibliographic survey on the use of Bacillus thuringiensis as a form of biological control of Aedes aegypti larvae, due to the need to use safer and more effective methods of control for disease vector insects.

Pre- and Post-Intervention Study on Aedes Larvae in Water Storage Containers Adding of Native Larvivorous Fish Aplocheilus panchax in Hpa-an Township, Kayin State

Effective mosquito control strategies in temporary water storage containers in community are urgently needed to reduce dengue fever and dengue hemorrhagic fever through mosquito larvae reduction without harmful to environment, ecosystems and community. For biological control of Aedes aegypti larvae, native larvivorus fish as Aplocheilus panchax were collected from Hpa-an Township, Kayin State. Mingalar Ywar Thit and Taung Nar Village were selected as test and control villages and 51 households each were randomly selected to recruit the study. Laboratory and field study were done from February 2016 to January 2017. In the laboratory, a series of laboratory experiments compared Aedes larva consuming rates of Aplocheilus panchax and Trichogaster trichopterus in different water volumes, in order to determine their potential as larva control agent in water storage containers. In the field, Aedes larvae and pupae positivity in containers were recorded in both villages. During intervention, two Aplocheilus panchax were put into all major, minor and miscellaneous containers monthly for 3 months in test area of Mingalar Ywar Thit Village. Larval and pupal indices were determined before and after intervention. Laboratory result found that one gram weight of Aplocheilus panchax consumed 463.04 3rd and 4th instar Aedes larvae within 24 hours. It was 3.727 fold higher in consuming rate than one gram of Trichogaster trichopterus against 124.24 Aedes aegypti larvae. After intervention, House Index (HI), Container Index (CI) and Breteau Index (BI) were significantly reduced from 86.27%, 59.86% and 172.55 to 1.96%, 1.36% and 3.92, respectively (P<0.05). Hundred percent reduction was found in key containers and 90% reduction was found in key premises in test area. Pupal indices were also significantly reduced. Native larvivorus fish Aplocheilux panchax is an efficient biological agent for the control of DF and DHF vector Aedes immature stages in Kayin State. The biological method is simple and cost-effective method for control of DF/DHF in community.

Prolonged mosquitocidal activity of Siparuna guianensis essential oil encapsulated in chitosan nanoparticles.

BackgroundThe use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate.ResultsWe assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles.ConclusionsThe encapsulation of S. guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae. aegypti.

Eficácia de ectoparasiticidas contra larvas de Aedes aegypti: nota de pesquisa

Foi avaliada a eficácia de produtos ectoparasiticidas contra larvas de Aedes aegypti. Os princípios ativos fluazuron 2,5 g, cipermetrina 150 g, flumetrina 1 g, propoxur 1 g, deltametrina 25 g, clorpirifós 30 g, cipermetrina 15 g, fenthion 15 g, diazinon técnico estabilizado 40 g, fipronil 2,5%, triclorfone 97 g, coumafós 3 g, propoxur 2 g, fentione 15 g e amitraz 12,5% foram adquiridos comercialmente e preparados conforme recomendações dos fabricantes. Os produtos foram distribuídos em recipientes individuais contendo larvas de A. aegypti em ambiente controlado. A inspeção da viabilidade larval foi verificada durante 24 horas. Os produtos foram aplicados nos locais de coleta das larvas (criadouros dos mosquitos), vistoriados diariamente por um mês. Foi observado que 100% das larvas morreram em até 60 minutos, tanto nos recipientes monitorados em laboratório como no meio ambiente. Nas áreas em que foi realizada a pulverização com os inseticidas supramencionados, não foi verificada a presença de larvas por um período de até 30 dias. Concluiu-se que produtos comumente utilizados em animais como ectoparasiticidas foram eficazes contra larvas de A. aegypti, podendo ser utilizados para o controle desse importante vetor, caso tal utilização seja analisada e regulamentada pelos órgãos oficiais do país.

UJI MEDIA PEMELIHARAAN <em>Mesocyclops aspericornis</em> (Daday) DARI BERBAGAI KOTORAN TERNAK UNTUK MENINGKATKAN PRODUKSI COPEPODIT

Natural predators of mosquito larvae are known and used as biological control of the mosquito larvae of Aedes aegypti , one of them is a copepod, Mesocyclops aspericornis . The effectiveness of the biological control of Aedes aegypti larvae requires an efficient method to rear Mesocyclops aspericornis copepodite. This research aimed to determine the feasibility of various organic manures, i.e., cow dung (RKS), goat manure (RKK), and marmot manure (RKM) as aquaculture media of M. aspericornis copepodite. This experiment was conducted in the laboratory using a post-test only control group design. The group design consisted of 5 concentrations of 0%, 25%, 50%, 75%, and 100%, each with three replicates for each organic manure media. The statistical analyses showed each organic manure medium was not significantly affecting (p = 0.521) the copepod aquaculture. However, the concentration of the manure has a significant correlation with the number of copepodites raised (p = 0.001). Games-Howell test suggested the most effective manure concentration to rear M. aspericornis copepodite was 25%.

Isolation and molecular characterization of Bacillus thuringiensis found in soils of the Cerrado region of Brazil, and their toxicity to Aedes aegypti larvae

This study investigated the potential of Bacillus thuringiensis isolates obtained in the Cerrado region of the Brazilian state of Maranhão for the biological control of Aedes aegypti larvae. The isolates were obtained from soil samples and the identification of the B. thuringiensis colonies was based on morphological characteristics. Bioassays were run to assess the pathogenicity and toxicity of the different strains of the B. thuringiensis against third-instar larvae of A. aegypti. Protein profiles were obtained by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Polymerase chain reaction assays were used to detect the toxin genes found in the bacterial isolates. Overall, 12 (4.0%) of the 300 isolates obtained from 45 soil samples were found to present larvicidal activity, with the BtMA-104, BtMA-401 and BtMA-560 isolates causing 100% of mortality. The BtMA-401 isolate was the most virulent, with the lowest median lethal concentration (LC50) (0.004×107spores/mL), followed by the Bacillus thuringiensis var. israelensis standard (0.32×107spores/mL). The protein profiles of BtMA-25 and BtMA-401 isolates indicated the presence of molecular mass consistent with the presence of the proteins Cry4Aa, Cry11Aa and Cyt1, similar to the profile of Bacillus thuringiensis var. israelensis IPS-82. Surprisingly, however, none of the cry and cyt genes analyzed were amplified in the isolate BtMA-401. The results of the present study revealed the larvicidal potential of B. thuringiensis isolates found in the soils of the Cerrado region from Maranhão, although further research will be necessary to better elucidate and describe other genes associated with the production of insecticidal toxins in these isolates.

Photodynamic control of Aedes aegypti larvae (Diptera: Culicidae)

Photodynamic control of Aedes aegypti larvae (Diptera: Culicidae)

A biodegradable device for the controlled release of Piper nigrum (Piperaceae) standardized extract to control Aedes aegypti (Diptera, Culicidae) larvae.

The significant increase in dengue, Zika, and chikungunya and the resistance of the Aedes aegypti mosquito to major insecticides emphasize the importance of studying alternatives to control this vector. The aim of this study was to develop a controlled-release device containing Piper nigrum extract and to study its larvicidal activity against Aedes aegypti. Piper nigrum extract was produced by maceration, standardized in piperine, and incorporated into cotton threads, which were inserted into hydrogel cylinders manufactured by the extrusion of carrageenan and carob. The piperine content of the extract and thread reservoirs was quantified by chromatography. The release profile from the device was assessed in aqueous medium and the larvicidal and residual activities of the standardized extract as well as of the controlled-release device were examined in Aedes aegypti larvae. The standardized extract contained 580mg/g of piperine and an LC50 value of 5.35ppm (24h) and the 3 cm thread reservoirs contained 13.83 ± 1.81mg of piperine. The device showed zero-order release of piperine for 16 days. The P. nigrum extract (25ppm) showed maximum residual larvicidal activity for 10 days, decreasing progressively thereafter. The device had a residual larvicidal activity for up to 37 days. The device provided controlled release of Piper nigrum extract with residual activity for 37 days. The device is easy to manufacture and may represent an effective alternative for the control of Aedes aegypti larvae in small water containers.

A 104 kDa Aedes aegypti aminopeptidase N is a putative receptor for the Cry11Aa toxin from Bacillus thuringiensis subsp. israelensis

The Cry11Aa protein produced in Bacillus thuringiensis subsp. israelensis, a bacterial strain used worldwide for the control of Aedes aegypti larvae, binds midgut brush border membrane vesicles (BBMV) with an apparent Kd of 29.8 nM. Previously an aminopeptidase N (APN), named AaeAPN2, was identified as a putative Cry11Aa toxin binding protein by pull-down assays using biotinylated Cry11Aa toxin (Chen et al., 2009. Insect Biochem. Mol. Biol. 39, 688–696). Here we show this protein localizes to the apical membrane of epithelial cells in proximal and distal regions of larval caeca. The AaeAPN2 protein binds Cry11Aa with high affinity, 8.6 nM. The full-length and fragments of AaeAPN2 were cloned and expressed in Escherichia coli. The toxin-binding region was identified and further competitive assays demonstrated that Cry11Aa binding to BBMV was efficiently competed by the full-length AaeAPN2 and the fragments of AaeAPN2b and AaeAPN2e. In bioassays against Ae. aegypti larvae, the presence of full-length and a partial fragment (AaeAPN2b) of AaeAPN2 enhanced Cry11Aa larval mortality. Taken together, we conclude that AaeAPN2 is a binding protein and plays a role in Cry11Aa toxicity.

Dengue control in Ribeirão Preto, São Paulo, Brazil.

Following an epidemic of type I dengue in late 1990, the municipality of Ribeirão Preto (State of São Paulo, Brazil) assumed direct responsibility for the control of Aedes aegypti larvae. Control activities are presented in this report and are based on popular participation in environmental management. Massive use of the communications media, participation by schoolchildren, constant contact with the population, and integration of various public agencies are the program's priorities. Although the drop in the number of susceptibles may have played a role in the reduction of cases after the initial epidemic, the intense preventive campaign certainly helped quell the disease in the city, since changes were observed in the behavior of the population towards potential breeding sites. The occurrence of new cases in recent years appears to be related to greater circulation of the virus in both the State of São Paulo and Brazil as a whole, indicating the need for control measures at the national and continental level, without which it will be difficult to maintain low transmission rates, even in areas submitted to intense preventive work

Influence of the copepod Mesocyclops longisetus (Crustacea: Cyclopidae) on the survival of Vibrio cholerae O1 in fresh water.

In an experimental microcosm, an analysis was performed of the influence exerted by freshwater Mesocyclops longisetus copepods on the survival of Vibrio cholerae O1 serovar Inaba. In the State of Ceará, copepods are used in the control of Aedes aegypti larvae. The system consisted of water with a salinity of 0.27 per 10,000 habitants and pH 7.5, which after sterilizing filtration was distributed into seven flasks with a volume of 400 ml; in each of six flasks, 10 live copepods were inoculated along with 1 ml of an 8-hour culture of Vibrio cholerae O1 at 37oC in Alkaline Peptone Water, resulting in a concentration of 3.80x10(4) colony-forming units. The control flask contained only the water with the same bacterial suspension. The system was maintained for six days at room temperature (25-28oC), and daily duplicate counts were performed in TCBS Agar. Results confirmed a clear association between Vibrio cholerae O1 and the live copepods, based on survival of the bacteria at compatible levels with the initial inoculation until the sixth day of the analysis.