Search results for: Ae. aegypti insecticide

Authors: Nurul Hidayah, Farida Rahmatika, Fathimah Azzahra, Nesty Herennadia

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Aromatherapy candles are one of the insecticide media that have not been much researched. The active ingredient that is proven to have the effect of insecticide is a citrus extract from lemongrass oil (Cymbopogon). Aromatherapy candles are added by citrus compounds to be insecticidal for Ae. aegypti mosquito that was related to the infectious disease such as dengue fever. This research aims to find out if aromatherapy candles of citrus compounds have an insecticidal effect on Ae. aegypti mosquito. We used true experimental design including posttest only with control group design. The samples are 20 male and female Ae. aegypti mosquitos with aged 1-7 days belong to the inclusion criteria. The subjects were divided into 6 groups, consisting of 1 negative control group and 5 treatment groups with variation concentration are 1%; 2%; 3%; 4%; 5%. Each group will be treated for 2 hours and observed death after 24 hours. Replication in each group is done 4 times. The results were then tested statistically using Kruskal-Wallis and probit test. Mean of death in negative control group, and treatment group 1%; 2%; 3%; 4%; 5% respectively 0; 1; 0.25; 0; 1 and 1 mosquito. The Kruskal-Wallis test in the study group found no significant difference (p = 0.178). The probit analysis showed that LC50 and LC90 were 20.069% and 31.557%. The aromatherapy candle of a citrus compound has an insecticidal effect on the Ae aegypti mosquito.

Keywords: Ae. aegypti insecticide, aromatherapy candle, citrus compound, lemongrass oil (Cymbopogon)

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Authors: A. H. Maimusa, A. Abu Hassan, Nur Faeza A. Kassim

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In this study, we report on the main life table developmental attributes of laboratory colonies of wild strains Ae. albopictus and Ae. aegypti. The raw life history data of the two species were analyzed and compared based on the age-stage and two-sex life table. The total pre-adult development times were 9.47 days (Ae. albopictus) and 8.76 days (Ae. aegypti). The adult pre-oviposition periods (APOP) was 1.61 day for Ae. albopictus and 2.02 for Ae. aegypti. The total pre-oviposition period (TPOP) of Ae. albopictus is significantly longer (11.66 days) than (10.75 days) for Ae. aegypti. The mean intrinsic rate of increase (r) was 0.124 days (Ae. albopictus) and 1.151 days (Ae. aegypti) while the mean finite rate of increase (λ) was 1.13 day (Ae. albopictus) and (1.16 d) (Ae. aegypti). The net reproductive rates (Ro) were 8.10 and 10.75 for Ae. albopictus and Ae. aegypti, respectively. The mean generation time (T) for Ae. albopictus and Ae. aegypti, were 16.81 days and 15.77 days respectively. The mean development time for each stage insignificantly correlated with temperature (r = -0.208, p > 0.05) and (r = -0.312, p > 0.05) for Ae. albopictus and Ae. aegypti respectively. The life expectancy was 19.01 and 19.94 days for Ae. albopictus and Ae. aegypti respectively. Mortality occurred mostly during the adult stage and ranged between 0.01 and 0.07%. The population parameters suggest that Ae. albopictus and Ae. aegypti populations are r-strategist characterized by a high r, a large Ro, and short T. This kind of information is crucial in understanding mosquito population dynamics in disease transmission and control.

Keywords: Ae. aegypti, Ae. albopictus, age-stage, life table, two-sex

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Authors: Neera Kapoor

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Background: Knockdown Resistance (KDR) is one of the mechanisms of insecticide resistance in insects caused by the reduced target site sensitivity i.e. voltage gated sodium channel (VGSC) rendering it less sensitive to the toxic effects of DDT and pyrethroids. In this study, we evaluated insecticide susceptibility and its underlying KDR mechanism in eight Ae. aegypti and five Ae. albopictus field populations. Methodology: Field population was collected from four different geographical regions of India covering 18 districts of ten states. For genotyping of twelve KDR alleles in Ae. aegypti field populations, three PCR based assays were used; with DNA sequencing; ASPCR; PCR-RFLP. Genomic DNA was isolated, and three partial domains (II, III, and IV) of VGSC were amplified and sequenced. Results: Molecular screening for common KDR mutations, revealed the presence of five mutations viz. S989P, V1016G, T1520I, F1534C/L. Two novel mutations were observed, first at T1520 (ACC) residue where a C > T substitution at the second position of codon results in amino acid change to Isoleucine (ATC). Second mutation was an alternative point mutation at F1534 (TTC) residue where a substitution of T > C at the first position of codon results in an amino acid change to Leucine (CTC). ASPCRs were not accurate, so three PCR-RFLP assays were developed for genotyping of five KDR alleles in Ae. aegypti; viz. T1520I, F1534C/L. Representative samples of all genotypes (n=200) were sequenced to validate the newly developed PCR based assays for Ae. aegypti. Genotyping results showed that 989P is linked to 1016G and novel mutation 1520I was always found with 1534C allele. Conclusion: Present study confirmed the presence of DDT and pyrethroid resistance among Ae. aegypti populations in India and for the first time reported KDR mutations in this species from India including two novel mutations. Results of present study lead us to infer that, at least five KDR mutations (S989P, V1016G, T1530I, F1534C, and F1534L) can be seen as a potential marker for DDT/pyrethroid resistance.

Keywords: F1534C, F1534L, S989P, T1530I, V1016G

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Authors: Aarti Sharma, Sarita Kumar, Pushplata Tripathi

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Aedes aegypti L. is one of the most important insect vectors in the world transmitting several diseases of concern; dengue fever, dengue haemorrhagic fever and yellow fever. Though since ages the control of dengue vector is primarily relied upon the use of synthetic chemical insecticides, the continued and indiscriminate use of insecticides for their control has received wide public apprehension because of multifarious problems including insecticide resistance, resurgence of pest species, environmental pollution, toxic hazards to humans and non-target organisms. These problems have necessitated the need to explore and develop alternative strategies using eco-friendly and bio-degradable plant products. Bio-insecticides, despite being the focus of research nowadays, have not been investigated much regarding their physiological effects on the mosquitoes. Thus, the present studies were carried out to investigate the anti-mosquito potential of the leaf and stem hexane extracts of Achyranthes aspera against early fourth instars of Aedes aegypti L and their effects on the histological architecture of their midgut. The larvicidal bioassays conducted with the A. aspera leaf hexane extracts revealed the respective LC30, LC50 and LC90 values of 66.545 ppm, 82.555 ppm, 139.817 ppm while the assays with stem hexane extracts resulted in respective values of 54.982 ppm, 68.133 ppm, 115.075 ppm. The studies clearly indicate the efficacy of extracts as larvicidal agents against Ae. aegypti, the stem extracts being found more effective than the leaf extracts. When the larvae assayed with extracts were investigated for the modifications in the histo-architecture of the midgut, the studies showed significant damage, shrinkage, distortion and vacuolization of gut tissues and peritrophic membrane causing disintegration of epithelial cells and cytoplasmic organelles; extent of toxicity and damage varied depending upon the concentration and exposure time period. These changes revealed appreciable stomach poison potential of A. aspera extracts against Ae. aegypti larvae, which may have also caused adverse impact on the growth and development of larvae. These effects were also found to be more pronounced with the stem extract than the leaf extract. Our findings may prove significant suggesting the use of A. aspera extract as a bio-insecticide against early fourth instar larvae of Ae. aegypti. Further studies are needed to identify the bioactive component in the extracts and to ascertain the use of component in the fields as anti-mosquito control agent.

Keywords: Achyranthes aspera, Aedes aegypti, histological architecture, larvicidal, midgut, stomach poison

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Authors: Ida Bagus Mandhara Brasika, I Dewa Gde Sathya Deva

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Wolbachia is recently developed as the natural enemy of Dengue virus (DENV). It inhibits the replication of DENV in Aedes aegypti. Both DENV and its vector, Aedes aegypty, are sensitive to climate factor especially temperature. The changing of climate has a direct impact on temperature which means changing the vector transmission. Temperature has been known to effect Wolbachia density as it has an ideal temperature to grow. Some scenarios, which are known as Representative Concentration Pathways (RCPs), have been developed by Intergovernmental Panel on Climate Change (IPCC) to predict the future climate based on greenhouse gases concentration. These scenarios are applied to mitigate the future change of Aedes aegypti migration and how Wolbachia could control the virus. The prediction will determine the schemes to release Wolbachia-injected Aedes aegypti to reduce DENV transmission.

Keywords: Aedes aegypti, climate change, dengue virus, Intergovernmental Panel on Climate Change, representative concentration pathways, Wolbachia

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Authors: Mohd Shazad, Kamal Kumar Gupta

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Aedes aegypti (Diptera: Culicidae), commonly known as tiger mosquito is the vector of dengue fever, yellow fever, chikungunya and zika virus. In the absence of any effective vaccine against these diseases, control the mosquito population is the only promising mean to prevent the diseases. Currently used chemical insecticides cause environmental contamination, high mammalian toxicity and hazards to non-target organisms, insecticide resistance and vector resurgence. Present research work aimed to explore the potentials of phytochemicals present in the Ocimum sanctum in management of mosquito population. The leaves of Ocimum were extracted with ethanol by ‘cold extraction method’. 0-24h old fourth instar larvae of Aedes aegypti were treated with the extract of concentrations 50ppm, 100ppm, 200ppm and 400ppm for 24h. Survival, growth and development of the treated larvae were evaluated. The adults emerged from the treated larvae were used for the reproductive fitness studies. Our results indicate 77.2% mortality in the larvae exposed to 400 ppm. At lower doses, although there was no significant reduction in the survival after 24h however, it decreased during subsequent days of observations. In control experiments, no mortality was observed. It was also observed that the larvae survived after treatment showed severe growth and developmental abnormalities. There was significant increase in larval duration. In control, fourth instar moulted into pupa after 3 days while larvae treated with 400 ppm extract were moulted after 4.6 days. Larva-pupa intermediates and the pupa-adult intermediates were observed in many cases. The adults emerged from the treated larvae showed impaired mating and oviposition behaviour. The females exhibited longer preoviposition period, reduced oviposition rate and decreased egg output. GCMS analysis of the ethanol extract revealed presence of JH mimics and intermediates of JH biosynthetic pathway. Potentials of Ocimum sanctum in integrated vector management programme of Aedes aegypti were discussed.

Keywords: Aedes aegypti, Ocimum sanctum, oviposition, survival

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Authors: Muhammad Sohail Sajid, Muhammad Abdullah Malik, Muhammad Saqib, Faiz Ahmad Raza, Waseem Akram

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Aedes (Ae.) aegypti, the vector of pathogens of one health significance, has gained currency over the last decade. The present study reports the prevalence of A. aegypti larvae in indoor and outdoor niches from the three districts of different agro-geo-climatic zones of Punjab, including Chakwal (north), Faisalabad (central), and Dera Ghazi Khan (south). Mosquito larvae were collected, preserved, and transferred for identification. The relevant data were collected on a predesigned questionnaire. Stegomyia indices, including House Index (HI), Breteau Index (BI), and Container Index (CI), were calculated. The association of different breeding containers with the prevalence of Ae. aegypti larvae were estimated through Chi-square analysis. The highest Stegomyia indices were calculated in Chakwal (HI = 46.61%, BI = 91.67%, and CI = 15.28%) as compared to Faisalabad (HI = 34.11%, BI = 68.75% and, CI = 13.04%) and DG Khan (HI = 28.39%, BI = 68.23% and, CI = 11.29%), respectively. Irrespective of the geographical area, earthen jars, water tanks, and tree holes were found to be significantly associated (p < 0.05) with the abundance of Ae. aegypti larvae. However, tires and plastic bottles in Faisalabad and DG Khan while flower tubs and plastic buckets in Faisalabad and Chakwal were found to be significantly associated (p < 0.05) with the larval abundance. The results are a maiden attempt to correlate the magnitude of Ae. aegypti larvae in various microclimatic niches of Punjab, Pakistan, which might help in policy-making for preventive management of the menace.

Keywords: Aedes aegypti, ecology, breeding habitats, Stegomyia indices, breeding containers

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Authors: M. D. Nirmani, K. L. N. Perera, G. H. Galhena

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Dengue has become one of the most important arbo-viral disease in all tropical and subtropical regions of the world. Aedes aegypti, is the principal vector of the virus, vary in both epidemiological and behavioral characteristics, which could be finely measured through DNA sequence comparison at their population level. Such knowledge in the population differences can assist in implementation of effective vector control strategies allowing to make estimates of the gene flow and adaptive genomic changes, which are important predictors of the spread of Wolbachia infection or insecticide resistance. As such, this study was undertaken to investigate the phylogenetic relationships of Ae. aegypti from Galle and Colombo, Sri Lanka, based on the ribosomal protein region which spans between two exons, in order to understand the geographical distribution of genetically distinct mosquito clades and its impact on mosquito control measures. A 320bp DNA region spanning from 681-930 bp, corresponding to the ribosomal protein, was sequenced in 62 Ae. aegypti larvae collected from Galle (N=30) and Colombo (N=32), Sri Lanka. The sequences were aligned using ClustalW and the haplotypes were determined with DnaSP 5.10. Phylogenetic relationships among haplotypes were constructed using the maximum likelihood method under Tamura 3 parameter model in MEGA 7.0.14 including three previously reported sequences of Australian (N=2) and Brazilian (N=1) Ae. aegypti. The bootstrap support was calculated using 1000 replicates and the tree was rooted using Aedes notoscriptus (GenBank accession No. KJ194101). Among all sequences, nineteen different haplotypes were found among which five haplotypes were shared between 80% of mosquitoes in the two populations. Seven haplotypes were unique to each of the population. Phylogenetic tree revealed two basal clades and a single derived clade. All observed haplotypes of the two Ae. aegypti populations were distributed in all the three clades, indicating a lack of genetic differentiation between populations. The Brazilian Ae. aegypti haplotype and one of the Australian haplotypes were grouped together with the Sri Lankan basal haplotype in the same basal clade, whereas the other Australian haplotype was found in the derived clade. Phylogram showed that Galle and Colombo Ae. aegypti populations are highly related to each other despite the large geographic distance (129 Km) indicating a substantial genetic similarity between them. This may have probably arisen from passive migration assisted by human travelling and trade through both land and water as the two areas are bordered by the sea. In addition, studied Sri Lankan mosquito populations were closely related to Australian and Brazilian samples. Probably this might have caused by shipping industry between the three countries as all of them are fully or partially enclosed by sea. For example, illegal fishing boats migrating to Australia by sea is perhaps a good mean of transportation of all life stages of mosquitoes from Sri Lanka. These findings indicate that extensive mosquito migrations occur between populations not only within the country, but also among other countries in the world which might be a main barrier to the successful vector control measures.

Keywords: Aedes aegypti, dengue control, extensive mosquito migration, haplotypes, phylogeny, ribosomal protein

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Authors: Suelen C. Lima, André C. de Oliveira, Rosemary A. Roque

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Dengue is fatal arboviruses transmitted by the A. aegypti mosquito to more than 100 countries, for which the WHO estimates that 2.5 million people will be infected by these disease. The widespread of these diseases is due, among other factors, to the resistance that A. aegypti has to several commercial insecticides. On the other hand, natural products based on plants of the genus Piper (Piperaceae) are characterized by their insecticidal activities against mosquitoes. Piper longepetiolatum and Piper brachypetiolatum are species with wide distribution in the State of Amazonas. However, there is no investigation of phytochemical or biological of these plants against mosquitoes such as A. aegypti. The main of this study was to identify the chemical composition of the essential oil (EOs) from P. longepetiolatum and P. brachypetiolatum and to evaluate the biological activity against A. aegypti. The EOs were extracted by hydrodistillation from leaves (200 g) of P. longepetiolatum and P. brachypetiolatum and analyzed by GC-MS and GC-FID. The main compounds β-caryophyllene (99.9% of purity) and E-nerolidol (99.4% of purity) were purchased from Sigma-Aldrich® Brazil. The larvicidal activity of EOs (20 to 100 ppm), β-caryophyllene and E-nerolidol (10 to 50 ppm) was performed according to WHO protocol against A. aegypti larvae. The GC-MS and GC-FID analysis of EOs from P. longepetiolatum and P. brachypetiolatum indicated the majority presence of β-caryophyllene (35.42%) and E-nerolidol (49.79%), respectively. The results showed that all natural products presented larvicidal activity against A. aegypti. In this aspect, the OE from P. brachypetiolatum (LC50 of 15.51 ppm and LC90 of 22.79 ppm) was more active than the OE from P. longepetiolatum (LC50 of 47.17 ppm and LC90 of 69.60 ppm) (p < 0.05). Regarding of main compounds, E-nerolidol (LC50 of 9.50 ppm and LC90 of 23.89 ppm) showed higher larvicidal activity than the β-caryophyllene compound (LC50 of 79.00 ppm and LC90 of 230.91 ppm) (p < 0.05). The larvae treated with these natural products showed tremors and lethargic movements, suggesting that these natural products have neurotoxic action. These observations support studies to investigate the mechanism of action. This is the first record of the chemical composition and larvicidal activity of the EO from P. longepetiolatum and P. brachypetiolatum rich in β-caryophyllene and E-nerolidol against A. aegypti larvae.

Keywords: piperaceae, aedes, sesquiterpenes, biological control

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Authors: Chioma Nwakanma, Onyeka Okoh Irene, Emmanuel Eze

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Pesticide residues left in agricultural soils after cropping are always accumulative, difficult to degrade and harmful to animals, plants, soil and human health in general. The biodegrading potential of pesticides- resistant PGPB on soil pollution was investigated using in situ remediation technique following recommended standards. In addition, screening for insecticide utilization, maximum insecticide concentration tolerance, insecticide biodegradation and insecticide residues analyses via gas chromatographic/electron column detector were determined. The location of bacterial degradation genes was also determined. Three plant growth-promoting rhizophere (PGPR) were isolated and identified according to 16S rRNA as Paraburkholderia tropica, Burkolderia glumae and Achromobacter insolitus. From the results, all the three isolates showed phosphate solubilizing traits and were able to grow on nitrogen free medium. The isolates were able to utilize the insecticide as sole carbon source and increase in biomass. They were statistically significantly tolerant to all the insecticide concentrations screened. The gas chromatographic profiles of the insecticide residues showed a reduction in the peak areas of the insecticides, indicating degradation. The bacterial consortium had the lowest peak areas, showing the highest degradation efficiency. The genes responsible for degradation were found to be in the plasmids of the isolates. Therefore, the use of PGPR is recommended for bioremediation of agricultural soil insecticide polluted areas and can also enhance soil fertility.

Keywords: biodegradation, rhizosphere, insecticides utilization, agricultural soil

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Authors: E. Satoh, R. Kasahara, T. Aoki, K. Fukatsu, D. Venkata Ramanarao, H. Harayama, T. Murata, A. Suwa

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Rice plant hoppers (Hemiptera: Delphacidae) have been causing extensive economic damage in rice and are considered as serious threat in rice producing countries of Asia. They have developed resistance to major groups of chemical insecticide, and severe outbreaks occur commonly throughout Asia. To control these nuisance pests, Nihon Nohyaku Co., Ltd., recently discovered an insecticide, benzpyrimoxan (proposed ISO name), which is under development as NNI-1501 (development code). Benzpyrimoxan has a unique chemical structure which contains benzyloxy and cyclic acetal groups on pyrimidine moiety (5-(1,3-dioxan-2-yl)-4-[4- (trifluoromethyl)benzyloxy]pyrimidine). In order to clarify the biological properties of benzpyrimoxan, we conducted several experiments and found the following results. Benzpyrimoxan has high activity against nymphal stages of rice plant hoppers without any adulticidal activity. It provides excellent and long lasting control against rice plant hoppers, including populations that have developed resistance to several other chemical groups of insecticide. The study on its mode of action is undergoing. These features highlight the versatility of this insecticide as an effective and valuable tool from the viewpoints of insecticide resistance management and integrated pest management program. With the use of benzpyrimoxan, farmers shall be able to lead the best yield potential by keeping the population density of rice plant hoppers and associated virus diseases under control.

Keywords: acetal, benzpyrimoxan, insecticide, NNI-1501, pyrimidine, rice plant hoppers

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Authors: Hadura Abu Hasan, Zairi Jaal, P. J. McCall

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Dengue is a serious problem in Malaysia, particularly in high-density urban communities with lower socio-economic levels. This study evaluated the susceptibility of local populations of Aedesaegypti (Linnaeus), Aedesalbopictus (Skuse) and Culexquinquefasciatus (Say) from the traditional community of BaganDalam, Penang, Malaysia to lambdacyhalothrin and pirimiphos-methyl using standard World Health Organization (WHO) adult bioassay test. Unfed female mosquitoes aged 3-5 days were exposed to WHO recommended dosages of insecticides over fixed time periods with results presented as knock-down time (KT50) for each strain.The insecticide susceptible VCRU laboratory strain was usedas control. All three specieswere highly resistant to lambda-cyhalothrin with less than 10% mortality at 24 hours after treatment. In contrast, Ae.aegypti and Ae. albopictus were susceptible to pirimiphos-methyl, showing 100% mortality recorded 24 hoursafter treatment. Cx. quinquefasciatuswasclassed as ‘suspected resistant’ to pirimiphos-methyl as mortality recorded 24 hours after treatment was 94-96%. The results indicate that organophosphates such as pirimiphos-methyl might be used as alternative to pyrethroid for dengue vector control in this dengue-prone area.

Keywords: vector control, aedes aegypti, aedes albopictus, dengue, culex quinquefasciatus, residuals insecticides, pyrethroid, organophosphate, resistant, mosquito

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Authors: R. O. B. Bitencourt, F. S. Farias, M. C. Freitas, C. J. R. Balduino, E.S. Mesquita, A. R. C. Corval, P. S. Gôlo, E. G. Pontes, V. R. E. P. Bittencourt, I. C. Angelo

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Aedes aegypti larval survival rate was assessed after exposure to blastopores or conidia (mineral oil-in-water formulation or aqueous suspension) of Beauveria bassiana CG 479 propagules (blastospores or conidia). Here, mineral oil was used in the fungal formulation to control Aedes aegypti larvae. 1%, 0.5% or 0.1% mineral oil-in-water solutions were used to evaluate mineral oil toxicity for mosquito larvae. In the oil toxicity test, 0.1% mineral oil solution reduced only 4.5% larval survival; accordingly, this concentration was chosen for fungal oil-in-water formulations. Aqueous suspensions were prepared using 0.01% Tween 80^® in sterile dechlorinated water. A. aegypti larvae (L₂) were exposed in aqueous suspensions or mineral oil-in-water fungal formulations at 1×107 propagules mL^-1; the survival rate (assessed daily, for 7 days) and the median survival time (S₅₀) were calculated. Seven days after the treatment, mosquito larvae survival rates were 8.56%, 16.22%, 58%, and 42.56% after exposure to oil-in-water blastospores, oil-in-water conidia, blastospores aqueous suspension and conidia aqueous suspension (respectively). Larvae exposed to 0.01% Tween 80^® had 100% survival rate and the ones treated with 0.1% mineral oil-in-water had 95.11% survival rate. Larvae treated with conidia (regardless the presence of oil) or treated with blastospores formulation had survival median time (S₅₀) ranging from one to two days. S₅₀ was not determined (ND) when larvae were exposed to blastospores aqueous suspension, 0.01% Tween 80^® (aqueous control) or 0.1% mineral oil-in-water formulation (oil control). B. bassiana conidia and blastospores (mineral oil-in-water formulated or suspended in water) had potential to control A. aegypti mosquito larvae, despite mineral oil-in-water formulation yielded better results in comparison to aqueous suspensions. Here, B. bassiana CG 479 isolate is suggested as a potential biocontrol agent of A. aegypti mosquito larvae.

Keywords: blastospores, formulation, mosquitoes, conidia

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Authors: Muhammad Saeed, Nazeer Ahmed, Mukhtar Alam, Fazli Subhan, Muhammad Adnan, Fazli Wahid, Hidayat Ullah, Rafiullah

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The present experiment evaluated different synthetic insecticides against Jassid (Amrasca devastations) on pea crop at Agriculture Research Institute Tarnab, Peshawar Khyber Pakhtunkhwa. The field was prepared to cultivate okra crop in Randomized Complete Block (RCB) Design having six treatments with four replications. Plant to plant and row to row distance was kept at 15 cm and 30 cm, respectively. Pre and post spray data were recorded randomly from the top, middle and bottom leaves of five selected plants. Five synthetic insecticides, namely Confidor (Proponil), a neonicotinoid insecticide, Chlorpyrifos (chlorinated organophosphate (OP) insecticide), Lazer (dinitroaniline) (Pendimethaline), Imidacloprid (neonicotinoids insecticide) and Thiodan (Endosulfan, organochlorine insecticide), were used against infestation of aphids, pea pod borer, stem fly, leaf minor and pea weevil. Each synthetic insecticide showed significantly more effectiveness than control (untreated plots) but was non-significant among each other. The lowest population density was recorded in the plot treated with synthetic insecticide i.e. Confidor (0.6175 liter.ha-1) (4.24 aphids plant⁻¹) which is followed by Imidacloprid (0.6175 liter.ha⁻¹) (4.64 pea pod borer plant⁻¹), Thiodan (1.729 liter.ha⁻¹) (4.78 leaf minor plant⁻¹), Lazer (2.47 liter.ha-1) (4.91 pea weevil plant⁻¹), Chlorpyrifos (1.86 liter.ha⁻¹) (5.11 stem fly plant⁻¹), respectively while the highest population was recorded from the control plot. It is concluded from the data that the residual effect decreases with time after the application of spray, which may be less dangerous to the environment and human beings and can effectively manage this dread.

Keywords: okra crop, jassids, Confidor, imidacloprid, chlorpyrifos, laser, Thiodan

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Authors: Koon Weng Lau, Chee Dhang Chen, Abdul Aziz Azidah, Mohd Sofian-Azirun

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Recently, Sarawak state of Malaysia encounter an outbreak of dengue fever. Aedes albopictus has incriminated as one of the important vectors of dengue transmission. Without an effective vaccine, approaches to control or prevent dengue will be a focus on the vectors. The control of Aedes mosquitoes is still dependent on the use of chemical insecticides and insecticide resistance represents a threat to the effectiveness of vector control. This study was conducted to determine the resistance status of 11 active ingredients representing four major insecticide classes: DDT, dieldrin, malathion, fenitrothion, bendiocarb, propoxur, etofenprox, deltamethrin, lambda-cyhalothrin, cyfluthrin, and permethrin. Standard WHO test procedures were conducted to determine the insecticide susceptibility. Aedes albopictus collected from Kapit (resistance ratio, RR = 1.04–3.02), Kuching (RR = 1.17–4.61), and Sibu (RR = 1.06–3.59) exhibited low resistance toward all insecticides except dieldrin. This study reveled that dieldrin is still effective against Ae. albopictus, followed by fenitrothion, cyfluthrin, and deltamethrin. In conclusion, Ae. albopictus in Sarawak exhibited different resistance levels toward various insecticides and alternative solutions should be implemented to prevent further deterioration of the condition.

Keywords: Aedes albopictus, dengue, insecticide resistance, Malaysia

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Authors: Fatima Huda Hallak

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The current study aimed to evaluate the activity of bacterial insecticide Vertinic against the second star larvae of Trogoderma granarium (Everts) by four treatments: A, B, C, D, at seven concentrations: 0.001, 0.01, 0.1,1,10,100,1000 PPM. The mortality rate of larvae was 100% at concentrations 10 and 100 in treatments A and B after 24 hours and after 48 hours in treatment D at 1 PPM. The efficiency of treatment A was greater as compared to treatment B at all concentrations and all exposure times. The efficiency of treatment D was greater as compared to treatment C; for example, at 0.001, 0.01, 0.1, 1 PPM, after 120 hours, the Mortality rate of larve was 6.76, 13.33, 43.33, 100% in treatment D, which it was 0.00, 0.00, 23.33, 96.67%, respectively in the treatment C.

Keywords: bacterial insecticide, trogoderma granarium (everts), fourth star larvae, vertimic

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Authors: Ait Hamlet Smina, Bensoltane Samira, Djekoun Mohamed, Berrebbah Houria

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In Algeria, the use of insecticides and other phytosanitary products are considerably spreading with the development of agriculture. But, the analyses of the residues of pesticides are not systematically made. In this context, we estimated through an experimental study, the effect of a neonicotinoid insecticide, the thiamethoxam which is used as a commercial preparation on the land snail Helix aspersa. This snail is one of the most abundant gastropod in North-East Algeria. Little information is available in the literature concerning the study of the biochemical markers of mollusks which are exposed to insecticides and especially, thiamethoxam.In this work, adult snails Helix aspersa were used to estimate the effect of a neonicotinoid insecticide (thiamethoxam) on the acetylcholinesterase (AChE), glutathione S-transferase (GST) and catalase (CAT) activities in this gastropod after a treatment of 6 weeks. During this period, snails were exposed by ingestion and contact to fresh lettuce leaves which were soaked with an insecticide solution. The thiamethoxam test solutions were 0, 25, 50, 100 and 200 mg/L, which are lower or equal to the concentrations that are applied in field. The results showed that the enzymatic activities of AChE and GST and CAT increased significantly with a dose-dependent manner. These results confirmed the toxic effect of thiamethoxam on snails exposed to the lettuce contaminated with this neonicotinoid insecticide, likely to be used as biomarker of exposure, at first to thiamethoxam then to other insecticides belonging to the same chemical family, currently present in the environment.

Keywords: helix aspersa, insecticide, thiamethoxam, AChE, GST, CAT

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Authors: Mohd Shazad, K. K. Gupta

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Vector borne diseases are a serious global concern. Aedes aegypti, the primary vector for viruses that cause dengue fever, dengue haemorrhagic fever, chikungunya and yellow fever is widespread over large areas of the tropics and subtropics. In last decade, diseases transmitted by Aedes aegypti are of serious concern. In past decade, number of cases of dengue fever, dengue hemorrhagic fever, and chikungunya has increased multifold. Present research work focused on impact of ethanol extract of Ocimum sanctum on dengue vector Aedes aegypti. 0-24 hr. old fourth instar larvae of lab-bred population of Aedes aegypti were exposed to ethanol leaf extract of Ocimum with concentrations ranging from 50 ppm to 400 ppm. Survival and development and the treated larvae and reproductive behaviour of the adults emerged from the treated larvae was evaluated. Our results indicated larvicidal potential of the leaf ethanol extract. The influence of the extract was dose dependent. 77.2% mortality was observed in the larvae exposed to 400 ppm for 24 hr. Treatment at lower concentrations revealed delayed toxicity. The larvae survived after treatment showed severe developmental anomalies. Consequently, there was the significant increase in duration of fourth instar larva. The L4 treated with 400-ppm extract moulted after 4.6 days; this was in sharp contrast to control where the larval period of the fourth instar lasts three days. The treated fourth instar larvae in many cases transformed into larva-pupa intermediates with the combination of larva, pupa characters. The larva-pupa intermediates had reduced life span and failed to moult successfully. The adults emerged from the larvae treated with lower doses had reduced reproductive potential. The females exhibited longer preoviposition period, reduced oviposition rate, abnormal oviposition behaviour and decreased fertility. Our studies indicated the possibility of the presence of JH mimic or JH analogue in the leaf ethanol extract of Ocimum. The present research work explored the potentials of Ocimum sanctum, also known as the queen of herbs, in integrated vector management programme of Aedes aegypti, which is a serious threat to human health.

Keywords: Aedes aegypti, development, mortality, Ocimum sanctum reproduction

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Authors: N. V. V. S. D. Prasad

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Field experiments were conducted at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh, India for two seasons during 2011-13 to evaluate the efficacy of flupyradifurone SL 200 a new class of insecticide in butenolide group against leaf hoppers, aphids and whitefly in Cotton. The test insecticide flupyradifurone 200 was evaluated at three doses @ 150, 200 and 250 g ai/ha ha along with imidacloprid 200 SL @ 20g ai/ha, acetamiprid 20 SP @ 20g ai/ha, thiamethoxam 25 WG @ 25g ai/ha and monocrotophos 36 SL @ 360 g ai/ha as standards. Flupyradifurone SL 200 even at lower dose of 150g ai/ha exhibited superior efficacy against cotton leafhopper, Amrasca devastans than the neonicotinoids which are widely used for control of sucking pests in cotton. Against cotton aphids, Aphis gossypii. Flupyradifurone SL 200 @ 200 and 250 g ai/ha ha was proved to be effective and the lower dose @ 150g ai/ha performed better than some of the neonicotinoids. The effect of flupyradifurone SL 200 on cotton against whitefly, Bemisia tabaci was evident at higher doses of 200 and 250 g ai/ha and superior to all standard treatments, however, the lower dose is at par with neonicotinoids. The seed cotton yield of flupyradifurone 200 SL at all the doses tested was superior than imidacloprid 200 SL @ 20g ai/ha and acetamiprid 20 SP @ 20g ai/ha. There is no significant difference among the insecticidal treatments with regards to natural enemies. The results clearly suggest that flupyradifurone is a new tool to combat sucking pest problems in cotton and can well fit in IRM strategies in light of wide spread insecticide resistance in cotton sucking pests.

Keywords: cotton, flupyradifurone, neonicotinoids, sucking pests

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Authors: Chanya Jetsukontorn

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Dengue hemorrhagic fever is the most important Mosquito-borne disease and the major public health problem in Thailand. The most important vector is Aedes aegypti. Environmental factors such as temperature, relative humidity, and biting rate affect dengue virus infection. The most effective measure for prevention is controlling of vector mosquitoes. In addition, surveillance of field-caught mosquitoes is imperative for determining the natural vector and can provide an early warning sign at risk of transmission in an area. In this study, Aedes aegypti mosquitoes were collected in Amphur Muang, Phetchabun Province, Thailand. The mosquitoes were collected in the rainy season and the dry season both indoor and outdoor. During mosquito’s collection, the data of environmental factors such as temperature, humidity and breeding sites were observed and recorded. After identified to species, mosquitoes were pooled according to genus/species, and sampling location. Pools consisted of a maximum of 10 Aedes mosquitoes. 70 pools of 675 Aedes aegypti were screened with RT-PCR for flaviviruses. To confirm individual infection for determining True infection rate, individual mosquitoes which gave positive results of flavivirus detection were tested for dengue virus by RT-PCR. The infection rate was 5.93% (4 positive individuals from 675 mosquitoes). The probability to detect dengue virus in mosquitoes at the neighbour’s houses was 1.25 times, especially where distances between neighboring houses and patient’s houses were less than 50 meters. The relative humidity in dengue-infected villages with dengue-infected mosquitoes was significantly higher than villages that free from dengue-infected mosquitoes. Indoor biting rate of Aedes aegypti was 14.87 times higher than outdoor, and biting times of 09.00-10.00, 10.00-11.00, 11.00-12.00 yielded 1.77, 1.46, 0.68mosquitoes/man-hour, respectively. These findings confirm environmental factors were related to Dengue infection in Thailand. Data obtained from this study will be useful for the prevention and control of the diseases.

Keywords: Aedes aegypti, Dengue virus, environmental factors, one health, PCR

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Authors: Brian F. Estidola, Alfredo A. Alcantara, Catherine del Cruz, Genelita S. Garcia

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This study aimed to investigate the effects of testosterone in the development and growth of Aedes aegypti as a main vector of dengue virus. There were three concentrations of testosterone: (0µM), (10µM), and (15µM) arranged randomly in two blocks. Each concentration houses 10 mosquitoes and monitored their development. The results showed that there were no significant differences on the effects of testosterone in emergence of larvae, mortality of eggs and larvae. However, it was shown that adults emerged from 15µM had a lower sex ratio than 10µM leading to the conclusion that there could be an optimal concentration of testosterone close to 10µM that could led to a high possibility of sex reversal of adult mosquitoes from female to male.

Keywords: mosquito, sex reversal, testosterone, ecdysterone

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Authors: Chantal Hendriks, Harry Gibson, Anna Trett, Penny Hancock, Catherine Moyes

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The use of modern inputs for crop protection, such as insecticides, is strongly underestimated in Sub-Saharan Africa. Several studies measured toxic concentrations of insecticides in fruits, vegetables and fish that were cultivated in Sub-Saharan Africa. The use of agricultural insecticides has impact on human and environmental health, but it also has the potential to impact on insecticide resistance in malaria transmitting mosquitos. To analyse associations between historic use of agricultural insecticides and the distribution of insecticide resistance through space and time, the use and environmental fate of agricultural insecticides needs to be mapped through the same time period. However, data on the use and environmental fate of agricultural insecticides in Africa are limited and therefore risk maps on the spatiotemporal occurrence of agricultural insecticides are created using environmental data. Environmental data on crop density and crop type were used to select the areas that most likely receive insecticides. These areas were verified by a literature review and expert knowledge. Pesticide fate models were compared to select most dominant processes that are involved in the environmental fate of insecticides and that can be mapped at a continental scale. The selected processes include: surface runoff, erosion, infiltration, volatilization and the storing and filtering capacity of soils. The processes indicate the risk for insecticide accumulation in soil, water, sediment and air. A compilation of all available data for traces of insecticides in the environment was used to validate the maps. The risk maps can result in space and time specific measures that reduce the risk of insecticide exposure to non-target organisms.

Keywords: crop protection, pesticide fate, tropics, insecticide resistance

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Authors: Zunnu Raen Akhtar, Farhan Ali, Muhammad Saeed-Ur-Rehman

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Jassids are considered as serious sucking pests in eggplants. Jassids can be controlled using imidacloprid, but it can also result in non-target ecological impacts on eco-system. It can also result in reduced population of predators of jassids in the field. An experiment was conducted on jassids, Amrasca sp. reared on eggplant leaves were treated with insecticide imidacloprid at lower, recommended and higher doses including 1L, 2L, 3L respectively. 3rd instar larvae and adults of jassids were exposed to lower, recommended, higher doses. Mortality tests were repeated three times for each dose and insect growth stage. Imidacloprid was sprayed on the leaves followed by drying. Data was recorded for 4, 8, 12, 16, 20, 24 hours after spraying insecticide on the leaves. Results showed that higher mortality was observed in higher and recommended doses, while slow mortality was observed in the case of lower dose. It can be asserted that higher and recommended doses causing immediate mortality of insects are better to control Amrasca sp. in the field, it will not cause immediate resistance development in insects against imidacloprid.

Keywords: Amrasca sp., imidacloprid, egg plant, efficacy

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Authors: Sandra Tapin-Lingua, Katia Ruel, Jean-Paul Joseleau, Daouia Messaoudi, Olivier Fahy, Michel Petit-Conil

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The preservative efficacy of organic biocides is strongly related to their capacity of penetration and retention within wood tissues. The specific detection of the pyrethroid insecticide is currently obtained after extraction followed by chemical analysis by chromatography techniques. However visualizing the insecticide molecule within the wood structure requires specific probes together with microscopy techniques. Therefore, the aim of the present work was to apply a new methodology based on antibody-antigen recognition and electronic microscopy to visualize directly pyrethroids in the wood material. A polyclonal antibody directed against cypermethrin was developed and implement it on Pinus sylvestris wood samples coated with technical cypermethrin. The antibody was tested on impregnated wood and the specific recognition of the insecticide was visualized in transmission electron microscopy (TEM). The immunogold-TEM assay evidenced the capacity of the synthetic biocide to penetrate in the wood. The depth of penetration was measured on sections taken at increasing distances from the coated surface of the wood. Such results correlated with chemical analyzes carried out by GC-ECD after extraction. In addition, the immuno-TEM investigation allowed visualizing, for the first time at the ultrastructure scale of resolution, that cypermethrin was able to diffuse within the secondary wood cell walls.

Keywords: cypermethrin, insecticide, wood penetration, wood retention, immuno-transmission electron microscopy, polyclonal antibody

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Authors: Josiane N. Muller, Allan K. R. Galardo, Tatiane A. Barbosa, Evan P. Ferro, Wellington M. Dos Santos, Ana Paula S. A. Correa, Edinaldo C. Rego, Jose B. P. Lima

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The susceptibility status of an insect population to any larvicide depends on several factors such includes genetic constitution, environmental conditions and others. The mosquito Aedes aegypti is the primary vector of three important viral diseases, Zika, Dengue, and Chikungunya. The frequent outbreaks of those diseases in different parts of Brazil demonstrate the importance of testing the susceptibility of vectors in different environments. Since the control of this mosquito leads to the control of disease, alternatives for vector control that value the different Brazilian environmental conditions are needed for effective actions. The aim of this study was to evaluate a new commercial formulation of Bacillus thuringiensis israelenses (DengueTech: Brazilian innovative technology) in the Brazilian Legal Amazon considering the climate conditions. Semi-field tests were conducted in the Institute of Scientific and Technological Research of the State of Amapa in two different environments, one in a shaded area and the other exposed to sunlight. The mosquito larvae were exposed to larvicide concentration and a control; each group was tested in three containers of 40 liters each. To assess persistence 50 third instar larvae of Aedes aegypti laboratory lineages (Rockefeller) and 50 larvae of Aedes aegypti collected in the municipality of Macapa, Brazil’s Amapa state, were added weekly and after 24 hours the mortality was assessed. In total 16 tests were performed, where 12 were done with replacement of water (1/5 of the volume, three times per week). The effectiveness of the product was determined through mortality of ≥ 80%, as recommend by the World Health Organization. The results demonstrated that high-water temperatures (26-35 °C) on the containers influenced the residual time of the product, where the maximum effect achieved was 21 days in the shaded area; and no effectiveness of 60 days was found in any of the tests, as expected according to the larvicide company. The test with and without water replacement did not present significant differences in the mortality rate. Considering the different environments and climate, these results stimulate the need to test larvicide and its effectiveness in specific environmental settings in order to identify the parameters required for better results. Thus, we see the importance of semi-field researches considering the local climate conditions for a successful control of Aedes aegypti.

Keywords: Aedes aegypti, bioassay, larvicida, vector control

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Authors: Flavia Cordeiro, Fabio Silva, Alvaro Eiras, Jose Luiz Acebal

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Aedes aegypti is present in the tropical and subtropical regions of the world and is a vector of several diseases such as dengue fever, yellow fever, chikungunya, zika etc. The growth in the number of arboviruses cases in the last decades became a matter of great concern worldwide. Meteorological factors like mean temperature and precipitation are known to influence the infestation by the species through effects on physiology and ecology, altering the fecundity, mortality, lifespan, dispersion behaviour and abundance of the vector. Models able to describe the dynamics of the vector population size should then take into account the meteorological variables. The relationship between meteorological factors and the population dynamics of Ae. aegypti adult females are studied to provide a good set of predictors to model the dynamics of the mosquito population size. The time-series data of capture of adult females of a public health surveillance program from the city of Lavras, MG, Brazil had its association with precipitation, humidity and temperature analysed through a set of statistical methods for time series analysis commonly adopted in Signal Processing, Information Theory and Neuroscience. Cross-correlation, multicollinearity test and whitened cross-correlation were applied to determine in which time lags would occur the influence of meteorological variables on the dynamics of the mosquito abundance. Among the findings, the studied case indicated strong collinearity between humidity and precipitation, and precipitation was selected to form a pair of descriptors together with temperature. In the techniques used, there were observed significant associations between infestation indicators and both temperature and precipitation in short, mid and long terms, evincing that those variables should be considered in entomological models and as public health indicators. A descriptive model used to test the results exhibits a strong correlation to data.

Keywords: Aedes aegypti, cross-correlation, multicollinearity, meteorological variables

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Authors: Monika Soni, Chandra Bhattacharya, Siraj Ahmed Ahmed, Prafulla Dutta

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Dengue is now a globally important arboviral disease. Extensive vector surveillance has already established A.aegypti as a primary vector, but A.albopictus is now accelerating the situation through gradual adaptation to human surroundings. Global destabilization and gradual climatic shift with rising in temperature have significantly expanded the geographic range of these species These versatile vectors also host Chikungunya, Zika, and yellow fever virus. Biggest challenge faced by endemic countries now is upsurge in co-infection reported with multiple serotypes and virus co-circulation. To foster vector control interventions and mitigate disease burden, there is surge for knowledge on vector susceptibility and viral tolerance in response to multiple infections. To address our understanding on transmission dynamics and reproductive fitness, both the vectors were exposed to single and dual combinations of all four dengue serotypes by artificial feeding and followed up to third generation. Artificial feeding observed significant difference in feeding rate for both the species where A.albopictus was poor artificial feeder (35-50%) compared to A.aegypti (95-97%) Robust sequential screening of viral antigen in mosquitoes was followed by Dengue NS1 ELISA, RT-PCR and Quantitative PCR. To observe viral dissemination in different mosquito tissues Indirect immunofluorescence assay was performed. Result showed that both the vectors were infected initially with all dengue(1-4)serotypes and its co-infection (D1 and D2, D1 and D3, D1 and D4, D2 and D4) combinations. In case of DENV-2 there was significant difference in the peak titer observed at 16th day post infection. But when exposed to dual infections A.aegypti supported all combinations of virus where A.albopictus only continued single infections in successive days. There was a significant negative effect on the fecundity and fertility of both the vectors compared to control (PANOVA < 0.001). In case of dengue 2 infected mosquito, fecundity in parent generation was significantly higher (PBonferroni < 0.001) for A.albopicus compare to A.aegypti but there was a complete loss of fecundity from second to third generation for A.albopictus. It was observed that A.aegypti becomes infected with multiple serotypes frequently even at low viral titres compared to A.albopictus. Possible reason for this could be the presence of wolbachia infection in A.albopictus or mosquito innate immune response, small RNA interference etc. Based on the observations it could be anticipated that transovarial transmission may not be an important phenomenon for clinical disease outcome, due to the absence of viral positivity by third generation. Also, Dengue NS1 ELISA can be used for preliminary viral detection in mosquitoes as more than 90% of the samples were found positive compared to RT-PCR and viral load estimation.

Keywords: co-infection, dengue, reproductive fitness, viral quantification

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Authors: Chee Dhang Chen, Hiroyuki Takaoka, Koon Weng Lau, Poh Ruey Tan, Ai Chdon Chin, Van Lun Low, Abdul Aziz Azidah, Mohd Sofian-Azirun

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Susceptibility status of Simulium (Simulium) nobile (Diptera: Simuliidae) adults obtained from Pahang, Malaysia was evaluated against 11 adulticides representing four major insecticide classes: organochlorines (DDT, dieldrin), organophosphates (malathion, fenitrothion), carbamates (bendiocarb, propoxur) and pyrethroids (etofenprox, deltamethrin, lambdacyhalothrin, permethrin, cyfluthrin). The adult bioassay was conducted according to WHO standard protocol to determine the insecticide susceptibility. Mortality at 24 h post treatment was used as indicator for susceptibility status. The results revealed that S. nobile obtained was susceptible to propoxur, cyfluthrin and bendiocarb with 100% mortality. S. nobile was resistant or exhibited some tolerant against lambdacyhalothrin and deltamethrin with mortality ranged ≥ 90% but < 98%. S. nobile populations in Pahang exhibited different level of resistant against 11 adulticides with mortality ranged from 60.00 ± 10.00 to 100.00 ± 0.00. In conclusion, S. nobile populations in Pahang were susceptible to propoxur, cyfluthrin and bendiocarb. The susceptibility status of S. nobile in descending order was propoxur, cyfluthrin > bendicarb > deltamethrin > lambdacyhalothrin > permethrin > etofenprox > DDT > malathion > fenitrothion > dieldrin. Regular surveys should be conducted to monitor the susceptibility status of this insect vector in order to prevent further development of resistance.

Keywords: black fly, adult bioassay, insecticide resistance, Malaysia

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Authors: Fernando L. P. Santos, Luiz G. Lyra, Helenice O. Florentino, Daniela R. Cantane

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Dengue is a febrile infectious disease caused by a virus of the family Flaviridae. It is transmitted by the bite of mosquitoes, usually of the genus Aedes aegypti. It occurs in tropical and subtropical areas of the world. This disease has been a major public health problem worldwide, especially in tropical countries such as Brazil, and its incidence has increased in recent years. Dengue is a subject of intense research. Efficient forms of mosquito control must be considered. In this work, the mono-objective optimal control problem was solved for analysing the dengue disease problem. Chemical and biological controls were considered in the mathematical aspect. This model describes the dynamics of mosquitoes in water and winged phases. We applied the genetic algorithms (GA) to obtain optimal strategies for the control of dengue. Numerical simulations have been performed to verify the versatility and the applicability of this algorithm. On the basis of the present results we may recommend the GA to solve optimal control problem with a large region of feasibility.

Keywords: genetic algorithm, dengue, Aedes aegypti, biological control, chemical control

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Authors: A. Jatau, Q. Majeed, H. M. Bandiya

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The efficacy of five local spices, namely; Hot pepper (Capsicum annum L.), Black pepper (Piper guinese Schum and Thonn), Sweet basil (Occimum canum Sim), African nut-meg (Monodora myristica Dunal), and Ginger (Zingiber officianale Ross) with conventional insecticide against the D. maculatus was studied under ambient laboratory conditions. The plants were pulverized into powders and applied at the rate of 1.0, 2.0 and 3.0g per 25g of disinfected dried fish. The same amount of fish (25g) was treated with 5ml of 1.0, 2.0 and 3.0 percent solution of conventional insecticide (dichlorvos) and air dried for 2hrs. Ten newly hatched 1st instar larvae (24hrs old) were introduced into each powdered smoked fish in separate beakers. Untreated control was also set up. Observation on the mortality and development were recorded daily until the larvae pupated. Each of the treated smoked fish showed significant (p<0.05) effect on the larval mortality and development when compared with the control. The Piper guinense was as efficacious as dichlorvos in killing all the larvae (100%) at all concentrations before pupation. Ocimum Canunm gave the second best results (50.00, 63.33 and 100%), while the other three spices resulted in less than 50% mortalities at all rate of application. The spice powders were also observed to have extended the larval developmental period. Thus, the spices tested can be recommended for the control of D. maculatus.

Keywords: development, dermestes maculatus, insecticide, local spices, mortality

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