Aedes Aegypti Larvae Research Articles

Effectiveness of Three Fruit Seed Extracts as Larvicide against Three Major Mosquito Vectors Aedes aegypti Linnaeus, Culex quinquefasciatus Say and Anopheles gambiae Giles (Diptera: Culicidae)

The CH2Cl2-MeOH (30:70 v/v) extracts of the seeds of Mangifera indica (Mango), Persea americana (Avocado) and Dacryodes edulis (African plum) were evaluated for potential mosquito larvicidal activity against 3rd and 4th instar larvae of Aedes aegypti, Culex quinquefasciatus and Anopheles gambiae. Extracts were diluted with 1 mL of methanol and concentrations ranging from 1000 to 125 mg/L in 4 replicates each, were prepared in the volume of 100 mL in the plastic cups (250 mL). A volume of 1 mL of methanol added to 99 mL of tap water was prepared as negative control and Bi-one (1000 mg/L) constituted a positive control. In each test solution, 25 larvae of each mosquito species were separately transferred and larval mortality was recorded after 24 h post-treatment. As results, the three plant seed extracts applied at 1000 mg/L caused for at least 79% mortality of each mosquito species larvae assessed. The seed extract of P. americana (LC50 of 98.31, 129.24 and 136.26 mg/L, respectively against An. gambiae, Ae. aegypti and Cx. quiquefasciatus larvae) was the most potent followed by D. edulis (LC50 of 176.87 mg/L for An. gambiae, 198.68 mg/L for Ae. aegypti and 201.70 mg/L for Cx. quinquefasciatus) and M. indica (LC50 of 258.98 mg/L for An. gambiae, 297.35 mg/L for Ae. aegypti and 435.45 mg/L for Cx. quinquefasciatus). Globally, all the seed extracts were more toxic against An. gambiae larvae compared to other mosquito species and need further exploration for the development of a new botanical larvicide to reduce mosquito densities.

Bacillus spp. metabolites are effective in eradicating Aedes aegypti (Diptera: Culicidae) larvae with low toxicity to non-target species

The growing spread of dengue, chikungunya and Zika viruses demand the development of new and environmentally safe control methods for their vector, the mosquito Aedes aegypti. This study aims to find novel larvicidal agents from mutualistic (endophytic and rhizospheric) or edaphic bacteria that have no action against non-target organisms. Eleven out of the 254 bacterial strains tested were able to kill Ae. aegypti larvae. Larvicidal activity did not depend on presence of cells, since culture supernatants or crude lipopeptide extracts (CLEs) killed the larvae. Bacillus safensis BacI67 and Bacillus paranthracis C21 supernatants were the best performing supernatants, displaying the lowest lethal concentrations (LC50 = 31.11 µL/mL and 45.84 µL/mL, respectively). Bacillus velezensis B64a and Bacillus velezensis B15 produced the best performing CLEs (LC50 = 0.11 mg/mL and 0.12 mg/mL, respectively). Mass spectrometry analysis of CLEs detected a mixture of surfactins, iturins, and fengycins. The samples tested were weakly- or non-toxic to mammalian cells (RAW 264.7 macrophages and VERO cells) and non-target organisms (Caenorhabditis elegans, Galleria mellonella, Scenedesmus obliquus, and Tetrahymena pyriformis) – especially B. velezensis B15 CLE. The biosynthetic gene clusters related to secondary metabolism identified by whole genome sequencing of the four best performing bacteria strains revealed clusters for bacteriocin, beta-lactone, lanthipeptide, non-ribosomal peptide synthetases, polyketide synthases (PKS), siderophores, T3PKS, type 1 PKS-like, terpenes, thiopeptides, and trans-AT-PKS. Purification of lipopeptides may clarify the mechanisms by which these extracts kill Ae. aegypti larvae.

CHEMICAL COMPOSITION AND OVICIDA ACTIVITY OF THE ESSENTIAL OIL OF CROTON ARGYROPHYLLUS (EUPHORBIACEAE) LEAVES ABOUT AEDES AEGYPTI (DIPTERA: CULICIDAE

The control of Aedes aegypti, which transmits several arboviruses of importance to public health, has as strategies the use of synthetic insecticides, integrated with environmental control. Its control is mainly directed to the larvae and adult phases. The egg phase is difficult to control, as it has great resistance to environmental conditions. The objective of this work was to evaluate the ovicidal potential of the essential oil obtained from the leaves of Croton argyrophyllus, on Aedes aegypti, as well as to determine the moisture content, the yield, and its chemical composition. The eggs were exposed to the aqueous solution of the essential oil in 10% Tween 80, in the concentration of 12 mg mL-1, for a period of 15, 30, 60, and 120 minutes. Subsequently, the eggs were washed and, after 180 hours of observation, the feed was added. The analysis of the chemical composition of the essential oil was performed by Gas Chromatography coupled to Mass Spectrometry. It was found that up to 180 hours of observation, the highest percentage of larval hatching occurred in eggs exposed to essential oil for 15 min (30%) and the lowest percentage in eggs exposed for 120 min ( less than 10%). After 180 hours, there was an increase in hatching in all treatments. The moisture content was 58.69%, the oil yield was 0.35%, and the main chemical constituents found were bicyclogermacrene and b-cariophylene. It was observed that the essential oil of Croton argyrophyllus, at the concentration evaluated, affects the hatching of Aedes aegypti larvae only in the absence of food.

Biological, histological and immunohistochemical studies on the toxicity of spent coffee grounds and caffeine on the larvae of Aedes aegypti (Diptera: Culicidae).

The mosquito Aedes aegypti is a primary vector for major arboviruses, and its control is mainly based on the use of insecticides. Caffeine and spent coffee grounds (CG) are potential agents in controlling Ae. aegypti by reducing survival and blocking larval development. In this study, we analyzed the effects of treatment with common CG (CCG: with caffeine), decaffeinated CG (DCG: with low caffeine), and pure caffeine on the survival, behavior, and morphology of the midgut of Ae. aegypti under laboratory conditions. Third instar larvae (L3) were exposed to different concentrations of CCG, DCG, and caffeine. All compounds significantly affected larval survival, and sublethal concentrations reduced larval locomotor activity, delayed development, and reduced adult life span. Damage to the midgut of treated larvae included changes in epithelial morphology, increased number of peroxidase-positive cells (more abundant in DCG-treated larvae), and caspase 3-positive cells (more abundant in CCG-treated larvae), suggesting that the treatments triggered cell damage, leading to activation of cell death. In addition, the treatments reduced the FMRFamide-positive enteroendocrine cells and dividing cells compared to the control. CG and caffeine have larvicidal effects on Ae. aegypti that warrant field testing for their potential to control mosquitoes.

Toxicological assessment of a bioactive extract from Triplaris gardneriana Wedd. seeds using alternative models

The Triplaris gardneriana Wedd. seeds extract has great therapeutic potential due to numerous biological activities such as antioxidant, antibacterial and anti-inflammatory, which are associated with phenolic content. Although this herbal preparation has shown many benefits, recently their toxicity profile has begun to be explored. In this present study, the toxic effects of T. gardneriana seeds ethanolic extract (EETg) on biological systems of different taxonomical groups and levels of complexity (from cell culture to lower vertebrates) were assessed, through a variety of viability and toxicological assays. It was found that EETg did not impair the Saccharomyces cerevisiae growth at the highest tested concentration (200 µg/mL), and no toxicant evidence was observed in Aedes aegypti larvae or in Drosophila melanogaster adult stage. Contrarily, the extract reduced the viability of undifferentiated Caco-2 cells (250 µg/mL, 40% of viable cells), but did not affect differentiated ones. The embryotoxicity in Danio rerio model showed a LC50 of 7.41 mg/L (95% confidence interval, 4.78 − 11.49 mg/L). EETg did not show signs of toxicity in the majority of the models used, but lethality and malformations in zebrafish embryos occurred. Further analyses are needed to better understand the selective toxicity mechanism of EETg on zebrafish, as well as whether the toxic effects happen in higher vertebrates.

Análisis espacial de un índice pupal de <i>Aedes aegypti</i>: una configuración del riesgo de transmisión de arbovirosis

El presente trabajo aborda un análisis espacial de un índice pupal (IP) de Aedes aegypti para establecer la aplicabilidad de la información geográfica y evaluar el riesgo de transmisión de arbovirosis en una localidad específica. Se obtuvo el IP y los índices de infestación tradicionales de larvas de Aedes aegypti en 366 viviendas, en una inspección del municipio de Tena (Cundinamarca, Colombia). La obtención de datos georreferenciados permitió analizar espacialmente las variables consideradas, con base en interpolaciones realizadas en un Sistema de Información Geográfica (SIG). Se contabilizaron 1.211 habitantes y se inspeccionaron 617 depósitos. Acorde con la clasificación de depósitos, los tanques bajos fueron los más frecuentes (51,0 %) y los más productivos, aportando el 93,3 % de las pupas. El índice de pupas por persona estimado en la localidad fue de 0,4. Se describe la heterogeneidad espacial del riego de transmisión de arbovirosis y de sus componentes. La implementación de la representación cartográfica de índices pupales, sumado a un análisis de riesgo de transmisión de arbovirosis, de acuerdo a la vulnerabilidad humana y la amenaza vectorial, constituyen aportes importantes a las estrategias de control y prevención, permitiendo una gestión optimizada de recursos por parte de los entes territoriales.

Effects of a solid formulation containing lectin-rich fraction of Moringa oleifera seeds on egg hatching and development of Aedes aegypti larvae

The measures currently used to minimize the spread of arboviruses, comprising dengue, Chikungunya, and Zika virus, involve controlling the size of population of the mosquito Aedes aegypti. However, the search for formulations containing new insecticides is gaining pace due to reports of mosquito populations showing resistance to commonly used compounds. In this study, tablets containing a protein fraction of Moringa oleifera seeds enriched in the WSMoL lectin, known to show larvicidal and ovicidal activities against A. aegypti, were developed. The compatibility between the fraction and the excipients used in obtaining the tablets was evaluated by thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) absorption spectroscopy. The larvicidal and ovicidal activities of the resulting tablets [5%, 10%, and 15% (w/w) of the fraction] were evaluated, as well as their effect on mosquito oviposition. Assays were also performed using a placebo tablet. According to the TG, DSC, and FTIR results, the protein composition of the fraction did not change when mixed with the components of the formulation. Tablets containing 10% and 15% WSMoL-rich fraction caused mortality of 42.5% and 95% of the larvae after 48 h, respectively, with larvae incubated with these tablets showing reduced acetylcholinesterase activity. All tablets inhibited egg hatching after 72 h (36–74%), and tablets containing 15% fraction were found to exert a repellent effect on oviposition. Our results show that the formulation developed in this study interfered with the life cycle of A. aegypti, and thus show potential for use in the control of this mosquito.

Influence of Income and Knowledge about Mosquito Nest Eradication (PSN DBD) to The Presence of Aedes aegypti Larvae

DHF still become health problem in Indonesia. In Central Java, especially Sukoharjo district, Angka Bebas Jentik (ABJ) is still under national standard. Some factors that influence the existence of larvae are the level of income and knowledge about PSN. Consumerism triggered escalation amount of mosquito breeding sites due to ownership of non-degradable goods like plastic containers, paper cups, and so on. Consumerism is related to income. This study has purpose to determine corelation between income levels and knowledge about PSN with existence of Aedes aegypti larvae in Karangtengah Village. Designed with cross-sectional approach. The population were residences that has Family Card in Karangtengah Village with a total of 1660 households taken 65 households. The independent variable is the level of income and knowledge about PSN. Dependent variable is existence of larvae. Data analysis used Chi-Square test and contingency coefficient (C). The results showed income with the existence of larvae (container index) (p = 0.009, C = 0.308) and PSN knowledge in the presence of larvae (container index) (p = 0.005, C = 0.332). The results of data analysis show that there is a correlation between income and knowledge about PSN with the existence of larvae. This study showed there is a relationship between income and knowledge about PSN with the existence of larvae.

Kalsium Hipoklorit (CaClO2) sebagai Pengganti Larvasida Aedes Aegypti

Dengue Hemorrhagic Fever (DHF) prevention can be done by eradicating Aedes aegypti larvae. One way to control larvae is by using larvicide biological or chemical. One type of larvicide that can be used is Calcium Hypochlorite (chlorine) as a substitute for S-Methoprene. The research objective was to determine the effectiveness of chlorine against the mortality of Aedes Aegyptus larvae. This study was an experimental study using three repetitions, the chlorine used consisted of doses of 1,0mg/l, 2,0mg/l, 3,0mg/l, 4,0mg/l, and 5,0mg/l which is applied with 1 liter of water that has been filled with 10 pcs of 3rd instar larvae. Data analysis used a completely randomized design by looking at the percentage of larval mortality within 15 minutes. The data on the number of deaths obtained were analyzed using the Anova test. Statistical results show that there is a difference in the number of deaths of Aedes aegypti larvae from each dose. The most effective dose of chlorine is 5,0mg/l. In conclusion, the more chlorine dose, the faster it will kill the larvae of Aedes aegypti larvae.Â

PENGEMBANGAN MAJALAH SAINS BERDASARKAN UJI PENGARUH KOMBINASI EKSTRAK DAUN BANDOTAN Agerantum conyzoides L. DAN DAUN SALAM Syzigum polyianthum TERHADAP LARVA NYAMUK Aedes aegypti

Abstract: This study aims to determine the effectiveness of combining leaf extract of Ageratum conyzoides L and Syzigium polyianthum against Aedes aegypti larvae. This study also wants to analyze the magazine's quality based on research in terms of feasibility based on expert judgment and attractiveness based on students' responses. The research method used Borg Gall's (1983) model. The research results of leaf extract of A. conyzoides and S. polyianthum against Aedes aegypti mosquito larvae effectively eradicate A. aegypti mosquito larvae because the increasing concentration increases the number of deaths of A. aegypti larvae. Meanwhile, the results of the validation test of science magazine products by media expert validators with a percentage of 75.5% (feasible), validation tests of science magazine products by material expert validators 75.45% (feasible), validation tests of science magazine products by practitioners of 95.5% (very feasible) and the results of student response tests of 94.62% (very interesting). The results showed that the science magazine developed was very feasible and very interesting to use in learning. Keywords: Ageratum conyzoides L, Syzigium polyianthum, Aedes aegypti

Urban climate maps as a public health tool for urban planning: The case of dengue fever in Rio De Janeiro/Brazil

The urban climate can influence the development of several diseases in the urban environment, among them dengue fever. The existing literature shows a strong correlation of the Aedes aegypti mosquito with climate, and especially with air temperature and humidity. The present study reveals a correlation between the surface temperature in the city of Rio de Janeiro and the distribution of Dengue vector larvae to provide suggestions for urban planning and public health/epidemiology for the control of the disease. In order to demonstrate this spatial correlation, mean annual surface temperature data obtained from the MODIS sensor and the spatial distribution of Aedes aegypti larvae were used to derive an ROC curve. The epidemic year of 2008 was selected to test the spatial correlation and the results were 67%. The influence of temperature on the spatial distribution of vector larvae in the epidemic years in the context of this study endorses the use of the urban climate map as a tool to help develop strategies for planning for and mitigating the problem. The characteristics of the urban site were derived using matrix algebra, in a GIS environment, and allowed us to identify those portions of the municipal territory that are most susceptible to heat storage - crucial to the reproduction and performance of the dengue fever vector in the transmission of the disease. In the city of Rio de Janeiro, high potential for heating was shown in the central and northern zones, as well as in the area of westward expansion of the city, which are also poorer and densely-populated areas.

Evidence of Metabolic Resistance in Pyrethroid Resistant Aedes aegypti Population from Lagos, Nigeria

Background: Pyrethroid resistance in Aedes aegypti is of major concern to the control of several arboviral infections. The major mechanisms of Pyrethroid resistance in mosquitoes are target-site insensitivity and elevation in the activity of detoxification enzymes. In this study, we assessed the susceptibility status of Aedes aegypti population from Lagos to Pyrethroid and the impact of metabolic enzymes on resistance development. Methods: Larvae of Aedes aegypti were collected from differ ent habitats in Lagos Mainland Local Government Area, Lagos state. Adult mosquitoes of 2-5 days were exposed to diagnostic dose of permethrin and Deltamethrin using the CDC method. Synergist assay was done with pre-exposure of samples to PBO before exposure to insecticide. Esterase and GST activities were measured using standard protocol. Regression Probit was used to compute the KDT50 and KDT95. Analysis of variance was used to compare the difference in mean of enzymes activities. Results: Aedes aegypti population from the study location is resistant to permethrin (33% ) and Deltamethrin (80%) within the diagnostic time. PBO pre-exposure increases percentage knockdown from 33% to 82% and 80% to 87% for permethrin and Deltamethrin respectively. The activity of GST was higher (P<0.05) in permethrin exposed mosquitoes in comparison with unexposed. Conclusion: A robust insecticide resistance management (IRM) plan in Lagos should take into consideration strategies for addressing the effects of metabolic enzymes in resistance development .

VULNERABILITY TEST OF Aedes aegypti LARVA AGAINST TEMEFOS IN WAY KANDIS, BANDAR LAMPUNG

Aedes aegypti is a major vector of Dengue Fever (DHF) that is spread through mosquito bites. However, Bandar Lampung ranked 3rd out of 15 districts in Lampung Province with an IR (Incidence Rate) of 59.43. One way to reduce dengue cases is vector control. Temefos is commonly used as a chemical vector's control and it is possible can cause resistance to larvae. The information about Aedes Aegypty has not been widely known about larval of Aedes aegypty's susceptibility towards Temefos in Lampung Province. Therefore, this study aims to determine the susceptibility status of Aedes aegypti larvae towards Temefos in Way Kandis Village, Tanjung Senang Regency, Bandar Lampung. This research was conducted in December 2018 - February 2019. This study uses five different temefos concentrations, i.e ;0 mg / L concentration as control, 0.005 mg / L, 0.01 mg / L, 0.02 mg / L, and 0 , Each 03 mg / L was repeated in 4 times. Observations were made by calculating the number of larvae that fainted, died, and lived. The results show that the susceptibility of Aedes aegypti towards Temefos in Way Kandis Village, Tanjung Senang Regency, Bandar Lampung City, is categorized as susceptible in the concentration range of 0.005 - 0.03 mg / L.

Efficacy of Antimicrobial and Larvicidal Activities of Green Synthesized Silver Nanoparticles Using Leaf Extract of Plumbago auriculata Lam.

This work reports the synthesis of silver nanoparticles (AgNPs) using aqueous extract of Plumbago auriculata, and evaluates their antibacterial and larvicidal activities. The synthesized silver nanoparticles were characterized by various spectroscopy techniques, such as FTIR, XRD, TEM, EDX, Zeta potential, and DLS. The synthesized AgNPs exhibited significant antibacterial activity against Gram-positive and Gram-negative bacteria, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. Furthermore, synthesized nanoparticles inhibited the fourth instars larvae of Aedes aegypti and Culex quinquefasciatus at the concentration of 45.1 and 41.1 µg/mL respectively. Results of dose-dependent studies showed that synthesized nanoparticles were also effective at low concentrations. Molecular docking studies performed with the salivary protein and odorant-binding protein of Aedes aegypti and Culex quinquefasciatus demonstrated that the naphthoquinone compound plumbagin exhibited reliable binding affinity towards the two enzymes. The findings thus reveal that the plant extract and its nanoparticles can be a better alternative to available chemicals to control mosquitos.

Larvicidal activity, route of interaction and ultrastructural changes in Aedes aegypti exposed to entomopathogenic fungi

Blastospores or conidia (formulated or not) of entomopathogenic fungi were assessed against Aedes aegypti larvae. Larvae (L2) were exposed to 105, 106, 107, and 108 propagules mL−1 water suspension. Mineral oil at 0.1%, 0.5%, or 1.0% (v/v) was employed to observe the effect on larval survival. The 0.1% mineral oil did not affect larval survival. Accordingly, 107 propagules mL−1 and 0.1% mineral oil were used to prepare all fungal emulsions. The fungal suspension or formulation was prepared as follows: 107 propagules mL−1 on 0.03% TweenⓇ 80 (v/v) aqueous solution or 107 propagules mL−1 on 0.03% TweenⓇ 80 plus 0.1% mineral oil; larval survival rates were evaluated for 7 days, and median survival time (S50) was also determined. The presence of fungi in larvae was examined both histologically and by scanning electron microscopy 24 h or 48 h after exposure. To evaluate the larval growth, larvae were exposed to 107 propagules mL−1 for 48 hours and their length measured using a digital caliper. Here, propagules had similar results in reducing the larvae survival rate and time. The treatment with Beauveria bassiana s.l. at 108 propagules mL−1 or with Metarhizium anisopliae s.l. at 108 blastopores mL−1 reduced the larval survival time to two days. M. anisopliae s.l. at 108 conidia mL−1 reduced the survival time to three days. The survival time of larvae submitted to the other treatments ranged from 6 days to over 7 days. M. anisopliae s.l. or B. bassiana s.l. oil-in-water emulsions at 107 propagules mL−1 yielded better results than the water suspensions, the larvae survival rate was 2 days for both propagules in oil-in-water emulsion. Larvae exposed to blastospores from both isolates or M. anisopliae conidia were longer than in the other treatments. Scanning electron microscopy and histology analyzes found fungi predominantly in the gut, mouthparts, and perispiracular lobes of larvae. Formulated fungus yielded better results than the aqueous suspensions for control of mosquito larvae. Thus, for the first time, the effect of mineral oil on the fungal interaction on A. aegypti larvae was observed as well as the effect of entomopathogenic fungi in the growth of larvae, supporting the search for strategies to control this arthropod.

Density of Aedes Aegypti Larvae Based on The Knowledge, Attitude and Action of The Manager and the Conversion in Al-Markaz Al-Islami Mosque, Makassar City

Purpose: This study aims to determine the density of Aedes aegypti larvae based on the knowledge, attitudes, and actions of the managers and congregants of the Al-Markas Al-Islami Mosque in Makassar City.
 Methods: This type of research is descriptive observational. There are two types of samples in this study, namely the sample of the management and congregation of the Al-Markaz Al-Islami Mosque in Makassar City and the sample of containers. For container samples as many as 165 containers. Data analysis using univariate analysis. The assessment of larvae density used the Container Index (CI) and Density Figure (DF) values.
 Results: The results of the analysis showed that the number of positive containers larvae was 41 containers with a CI value of 24.85% and a DF value of 6 in the high density category. Two categories were used to assess the level of knowledge, attitudes and actions of the respondents, namely the good category and the unfavorable category. The results of data analysis showed that 19 (54.3%) respondents had good knowledge and 16 (45.7%) respondents had poor knowledge, 21 (60%) respondents had good attitudes and 14 (40%) respondents had good attitudes. unfavorable, as many as 18 (51.4%) respondents had good actions and 17 (48.6%) respondents had unfavorable actions. It is advisable to do counseling about the dangers of dengue disease and health training related to efforts to eradicate mosquito nests.
 Conclusion: The density of Aedes aegypti larvae in containers at the Al-Markaz Al-Islami Mosque in Makassar City and the congregation's house is in the high density category.

Density of Aedes Aegypti Larves Based on Knowledge, Attitude and Action of Terminal Management in Daya Regional Terminal Kota Makassar

Purpose: This study aims to determine the density of Aedes aegypti larvae based on the knowledge, attitudes and actions of terminal managers at the Regional Terminal Daya Makassar City.
 Methods: The research design used was descriptive observational. There are two samples in this study, namely the container sample and the terminal manager sample. The sampling technique for containers used total sampling method and for terminal managers, purposive sampling method was used. Data were analyzed by univariate.
 Results: The results of the analysis showed that the number of positive containers for larvae was 69 (CI = 33%) with a value of DF = 8 and was a high density category. A total of 9 respondents (39.1%) had good knowledge and 14 respondents (60.9%) had poor knowledge. A total of 10 respondents (43.5%) had a good attitude and as many as 13 respondents (56.5%) had a bad attitude. In terms of action, (4.3%) of the respondents reflected good, while 22 respondents (95.7%) had actions in the unfavorable category.
 Conclusion: It is concluded that increasing public knowledge is essential to eradicate mosquito nests in the community. By enhancing the knowledge of the individuals, the PSN activities carried out routinely can break the life cycle of the mosquitoes that can cause DHF.The level of education that the terminal manager has, the better the ability to absorb the information provided will affect the knowledge held by the terminal manager.

Density of Aedes Aegypti Larvae Based on Knowledge, Attitude, and Action to Eradicate Mosquito Nest in Daya Market of Makassar City

Dengue Hemorrhagic Fever (DHF) is a disease caused by a dengue virus infection which is transmitted through the bite of the Aedes aegypti mosquito. To prevent the occurrence of dengue cases, it is necessary to eradicate mosquito nests. The market is one of the public places that has a risk of dengue transmission. This study aims to determine the density description of Aedes aegypti larvae based on the knowledge, attitudes and actions of cleaning managers, traders and visitors to Pasar Daya Makassar City. This type of research is descriptive observational. The research samples were cleaning managers, traders and visitors as well as containers at Pasar Daya and at the respondent's house. Sampling for respondents using purposive sampling method using inclusion and exclusion criteria. The results showed that the number of containers positive for ae.aegypti larvae in the Daya market was 34 containers with a container index value (CI) = 35.4% and the value of Density Figure (DF) 8 and the presence of Ae.aegypti larvae in the respondent's house (positive) amounting to (51.4%). At the level of knowledge of respondents in the poor category (68.6%), while the attitudes and actions of respondents in the poor category showed a high enough percentage, namely 65.7%, and (68.6%). Based on the results of this study, it can be concluded that the density of Aedes aegypti larvae in Pasar Daya Makassar City is in the high category.

Trials of the Automated Particle Counter for laboratory rearing of mosquito larvae.

As a means of obtaining reproducible and accurate numbers of larvae for laboratory rearing, we tested a large-particle flow-cytometer type device called the 'Automated Particle Counter' (APC). The APC is a gravity-fed, self-contained unit that detects changes in light intensity caused by larvae passing the detector in a water stream and controls dispensing by stopping the flow when the desired number has been reached. We determined the accuracy (number dispensed compared to the target value) and precision (distribution of number dispensed) of dispensing at a variety of counting sensitivity thresholds and larva throughput rates (larvae per second) using < 1-day old Anopheles gambiae and Aedes aegypti larvae. All measures were made using an APC algorithm called the 'Smoothed Z-Score' which allows the user to define how many standard deviations (Z scores) from the baseline light intensity a particle's absorbance must exceed to register a count. We dispensed a target number of 100 An. gambiae larvae using Z scores from 2.5-8 and observed no difference among them in the numbers dispensed for scores from 2.5-6, however, scores of 7 and 8 under-counted (over-dispensed) larvae. Using a Z score ≤ 6, we determined the effect of throughput rate on the accuracy of the device to dispense An. gambiae larvae. For rates ≤ 98 larvae per second, the accuracy of dispensing a target of 100 larvae was - 2.29% ± 0.72 (95% CI of the mean) with a mode of 99 (49 of 348 samples). When using a Z score of 3.5 and rates ≤ 100 larvae per second, the accuracy of dispensing a target of 100 Ae. aegypti was - 2.43% ± 1.26 (95% CI of the mean) with a mode of 100 (6 of 42 samples). No effect on survival was observed on the number of An. gambiae first stage larvae that reached adulthood as a function of dispensing.

Competition and growth among Aedes aegypti larvae: Effects of distributing food inputs over time.

Male and female mosquito larvae compete for different subsets of the yeast food resource in laboratory microcosms. Males compete more intensely with males, and females with females. The amount and timing of food inputs alters both growth and competition, but the effects are different between sexes. Increased density increases competition among males. Among females, density operates primarily by changing the food/larva or total food; this affects competition in some interactions and growth in others. Food added earlier in the life span contributes more to mass than the same quantity added later. After a period of starvation larvae appear to use some of the subsequent food input to rebuild physiological reserves in addition to building mass. The timing of pupation is affected by the independent factors and competition, but not in the same way for the two sexes, and not in the same way as mass at pupation for the two sexes. There is an effect of density on the timing of pupation for females independent of competition or changes in food/larva or total food. Male and female larvae have different larval life history strategies. Males grow quickly to a minimum size, then pupate, depending on the amount of food available. Males that do not grow quickly enough may delay pupation further to grow larger, resulting in a bimodal distribution of sizes and ages. Males appear to have a maximum size determined by the early food level. Females grow faster than males and grow larger than males on the same food inputs. Females affect the growth and competition among males by manipulating the number of particles in the microcosm through changes in feeding behavior. Mosquito larvae appear to have evolved to survive periods of starvation and take advantage of intermittent inputs of food into containers.