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Fulltext Checklist of the mosquito fauna (Diptera, Culicidae) of Cambodia

Maquart PO, Fontenille D, Rahola N, Yean S, Boyer S

Parasite, 2021;28:60.
PMID: 34374642 DOI: 10.1051/parasite/2021056

Between 2016 and 2020, the Medical and Veterinary Entomology unit of the Institut Pasteur du Cambodge collected over 230,000 mosquitoes. Based on this sampling effort, a checklist of 290 mosquito species in Cambodia is presented. This is the first attempt to list the Culicidae fauna of the country. We report 49 species for the first time in Cambodia. The 290 species belong to 20 genera: Aedeomyia (1 sp.), Aedes (55 spp.), Anopheles (53 spp.), Armigeres (26 spp.), Coquillettidia (3 spp.), Culex (57 spp.), Culiseta (1 sp.), Ficalbia (1 sp.), Heizmannia (10 spp.), Hodgesia (3 spp.), Lutzia (3 spp.), Malaya (2 spp.), Mansonia (5 spp.), Mimomyia (7 spp.), Orthopodomyia (3 spp.), Topomyia (4 spp.), Toxorhynchites (4 spp.), Tripteroides (6 spp.), Uranotaenia (27 spp.), and Verrallina (19 spp.). The Cambodian Culicidae fauna is discussed in its Southeast Asian context. Forty-three species are reported to be of medical importance, and are involved in the transmission of pathogens.

Matched MeSH terms: Aedes*
Optimal control strategies for dengue fever spread in Johor, Malaysia

Abidemi A, Aziz NAB

Comput Methods Programs Biomed, 2020 Nov;196:105585.
PMID: 32554024 DOI: 10.1016/j.cmpb.2020.105585

Background Dengue is a vector-borne viral disease endemic in Malaysia. The disease is presently a public health issue in the country. Hence, the use of mathematical model to gain insights into the transmission dynamics and derive the optimal control strategies for minimizing the spread of the disease is of great importance. Methods A model involving eight mutually exclusive compartments with the introduction of personal protection, larvicide and adulticide control strategies describing dengue fever transmission dynamics is presented. The control-induced basic reproduction number (R˜0) related to the model is computed using the next generation matrix method. Comparison theorem is used to analyse the global dynamics of the model. The model is fitted to the data related to the 2012 dengue outbreak in Johor, Malaysia, using the least-squares method. In a bid to optimally curtail dengue fever propagation, we apply optimal control theory to investigate the effect of several control strategies of combination of optimal personal protection, larvicide and adulticide controls on dengue fever dynamics. The resulting optimality system is simulated in MATLAB using fourth order Runge-Kutta scheme based on the forward-backward sweep method. In addition, cost-effectiveness analysis is performed to determine the most cost-effective strategy among the various control strategies analysed. Results Analysis of the model with control parameters shows that the model has two disease-free equilibria, namely, trivial equilibrium and biologically realistic disease-free equilibrium, and one endemic equilibrium point. It also reveals that the biologically realistic disease-free equilibrium is both locally and globally asymptotically stable whenever the inequality R˜0<1holds. In the case of model with time-dependent control functions, the optimality levels of the three control functions required to optimally control dengue disease transmission are derived. Conclusion We conclude that dengue fever transmission can be curtailed by adopting any of the several control strategies analysed in this study. Furthermore, a strategy which combines personal protection and adulticide controls is found to be the most cost-effective control strategy.

Matched MeSH terms: Aedes*
Fulltext Effectiveness of several locally available membranes used for artificial feeding of Aedes albopictus Skuse

Ooi CP, Rohani A, Zamree I, Chua WS

Trop Biomed, 2005 Jun;22(1):69-71.
PMID: 16880756 MyJurnal

Artificial feeding of mosquitoes with blood meal is an important technique in the studies of mosquito feeding. Owing to the difficulty in obtaining suitable artificial membranes for mosquito feeding from other sources, several easily obtainable membranes in Malaysia were tested for their suitability as a replacement. Skin of chicken, fish, and salted sausage were obtained and tested against cattle skin membrane as a control. The results showed that cattle skin is still the most favorable membrane to be used, with full engorgement rate of around 57% using fresh human blood. However, processed chicken skin was shown having potential for further testing since with feeding using human blood kept overnight at 4 degrees C, an engorgement rate of 50% was obtained.

Matched MeSH terms: Aedes*
Studies on the transmission of sub-periodic Brugia malayi by Aedes (Finlaya) togoi in the laboratory. I. The intake and migration of microfilariae

Ramachandran CP, Zaini MA

Med J Malaya, 1967 Dec;22(2):136-44.
PMID: 4231979
Matched MeSH terms: Aedes/physiology*
Relative abundance of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in different habitats

Yap HH, Thiruvengadam V

Med J Malaysia, 1979 Sep;34(1):76-9.
PMID: 44342
Matched MeSH terms: Aedes*
Studies on the transmission of sub-periodic Brugia malayi by Aedes (Finlaya) togoi in the laboratory. 3. The survival of infected mosquitoes under laboratory conditions

Ramachandran CP, Zaini MA

Med J Malaya, 1968 Jun;23(4):323-9 concl.
PMID: 4235597
Matched MeSH terms: Aedes*
Fulltext Collective behavior quantification on human odor effects against female Aedes aegypti mosquitoes-Open source development

Poh AH, Moghavvemi M, Leong CS, Lau YL, Safdari Ghandari A, Apau A, et al.

PLoS One, 2017;12(2):e0171555.
PMID: 28152031 DOI: 10.1371/journal.pone.0171555

Classifying and quantifying mosquito activity includes a plethora of categories, ranging from measuring flight speeds, repellency, feeding rates, and specific behaviors such as home entry, swooping and resting, among others. Entomologists have been progressing more toward using machine vision for efficiency for this endeavor. Digital methods have been used to study the behavior of insects in labs, for instance via three-dimensional tracking with specialized cameras to observe the reaction of mosquitoes towards human odor, heat and CO2, although virtually none was reported for several important fields, such as repellency studies which have a significant need for a proper response quantification. However, tracking mosquitoes individually is a challenge and only limited number of specimens can be studied. Although tracking large numbers of individual insects is hailed as one of the characteristics of an ideal automated image-based tracking system especially in 3D, it also is a costly method, often requiring specialized hardware and limited access to the algorithms used for mapping the specimens. The method proposed contributes towards (a) unlimited open source use, (b) a low-cost setup, (c) complete guide for any entomologist to adapt in terms of hardware and software, (d) simple to use, and (e) a lightweight data output for collective behavior analysis of mosquitoes. The setup is demonstrated by testing a simple response of mosquitoes in the presence of human odor versus control, one session with continuous human presence as a stimuli and the other with periodic presence. A group of female Aedes aegypti (Linnaeus) mosquitoes are released into a white-background chamber with a transparent acrylic panel on one side. The video feed of the mosquitoes are processed using filtered contours in a threshold-adjustable video. The mosquitoes in the chamber are mapped on the raster where the coordinates of each mosquito are recorded with the corresponding timestamp. The average distance of the blobs within the frames against time forms a spectra where behavioral patterns can be observed directly, whether any collective effect is observed. With this method, 3D tracking will not be required and a more straightforward data output can be obtained.

Matched MeSH terms: Aedes/physiology*
Efficacy of Mosquito Coils: Cross-resistance to Pyrethroids in Aedes aegypti (Diptera: Culicidae) From Indonesia

Amelia-Yap ZH, Chen CD, Sofian-Azirun M, Lau KW, Suana IW, Harmonis, et al.

J Econ Entomol, 2018 12 14;111(6):2854-2860.
PMID: 30265353 DOI: 10.1093/jee/toy296

Aedes aegypti (L.) (Diptera: Culicidae) is the primary vector of several arthropod-borne viral infectious diseases globally. Relentless vector control efforts are performed to curtail disease transmissions, insecticides remain as the first line of defense in Indonesia. With a dearth of publication on the efficacy of mosquito coil in Indonesia, this is the first report related to mosquito coil despite its common use in households. Ae. aegypti mosquitoes were sampled from nine regencies in Indonesia and tested using the glass-chamber method against three commercially available local pyrethroid-based mosquito coils containing d-allethrin, transfluthrin, and metofluthrin. The 50% knockdown time of female Ae. aegypti tested with d-allethrin, transfluthrin, and metofluthrin containing coils ranged from 0.65 to 14.32; 0.8 to 16.4; and 0.78 to 20.57 min, respectively. Mortality rates in accordance with WHO resistance indicators showed that strains from Denpasar, Mataram, Kuningan, Padang, Samarinda, and Sumba Timur were resistant (<80% mortality rate), whereas strains from Manggarai Barat, Dompu, and Pontianak were susceptible (>98% mortality rate) to the active ingredients assayed. Moreover, the knockdown rates between d-allethrin and transfluthrin, d-allethrin and metofluthrin, as well as transfluthrin and metofluthrin displayed significant associations, portraying the presence of cross-resistance within pyrethroid insecticides. The minimal insecticidal effect of mosquito coils against some Indonesian Ae. aegypti also pointed out the development of pyrethroid resistance, prompting a revamping of the vector control system.

Matched MeSH terms: Aedes*
Residual efficacy of deltamethrin applied to foliage against Malaysian Aedes aegypti (L.) and Aedes albopictus (Skuse)

Mohd-Noor SN, Nur-Rasyidah I, Muhammad-Iqbal MN, Nguyen TBD, Lee HL, Nurulhusna AH

Trop Biomed, 2021 Jun 01;38(2):165-170.
PMID: 34172706 DOI: 10.47665/tb.38.2.053

The spraying of insecticide on foliage to provide an insecticidal barrier may serve as part of the vector control measures to combat the increasing threat of Aedes-borne diseases. The effectiveness of insecticide barrier spraying was evaluated by assessing the residual efficacy of deltamethrin sprayed on foliage against Malaysian Ae. aegypti (L.) and Ae. albopictus (Skuse). In this semi-field study, landscape plants grown within the vicinity of the Institute for Medical Research (IMR), Malaysia, were treated with deltamethrin suspension concentrate (SC) with the dosage of 30 mg/m2 and 50 mg/m2 in three rounds of spraying. Deltamethrin residual activity on treated and untreated leaves was investigated using standard WHO cone bioassays. Wild Aedes populations at both deltamethrin-treated and untreated plant clusters were monitored by ovitrap surveillance. Ovitrap monitoring revealed that the mean number of Ae. albopictus larvae at deltamethrin-treated were significantly lower than the mean number of larvae of the same species at the untreated plant cluster. Cone bioassay results showed that the insecticide remained effective for up to 4 weeks (> 80% mortality), but the insecticide residual activity was affected by rainfall. These results suggest that insecticide barrier spraying is a promising tool and may be used along with other mosquito control tools such as indoor residual spray and space spraying to reduce the dengue burden.

Matched MeSH terms: Aedes*
Larvicidal potential of plant-based extracts against dengue vector: A short review

Noorazlan NAA, Camalxaman SN, Mohamed E, Haron N, Rambely AS, Dom NC, et al.

Med J Malaysia, 2024 Mar;79(Suppl 1):203-208.
PMID: 38555906

INTRODUCTION: Dengue fever, a vector borne disease transmitted primarily by Aedes albopictus and Aedes aegypti mosquitoes, has triggered a significant global resurgence. While many vector control programs depend on the use of chemical insecticides to curb outbreaks, its heavy reliance raises environmental concerns and the risk of insecticide resistance. Alternatively, botanically derived insecticidal agents with larvicidal properties offer an ecofriendlier option. This review aims to analyze scientific reports that described the effectiveness of plant-derived extracts for vector control.
MATERIALS AND METHODS: A literature search was performed to analyze studies that focused on plant-based extracts used for larvicidal purposes using databases such as Science Direct. Springer, PubMed, and Scopus. The inclusion criteria for publications were larvicidal effects, published in English from the year 2017 and availability of full-text articles. The available literature was further characterized by the value of larvicidal activities of LC50 and LC90 (< 50 ppm), of 22 different parts of plant species from 7 plant families namely Apiaceae, Asteraceae, Lauraceae, Magnoliaceae, Myrtaceae, Piperaceae and Rubiaceae.
RESULTS: When comparing the values of LC50, 12 plants species (Artemisia vulgaris, Crassocephalum crepidioides, Echinops grijsii, Melaleuca leucadendra, Neolitsea ellipsoidea, Pavetta tomentosa, Piper betle, Piper caninum, Piper Montium, Piper muntabile, Piper ovatum, Tarenna asiatica) showed promising larvicidal efficacies with LC50 < 10 ppm.
CONCLUSION: This review emphasizes the effective alternatives of plant extracts for the potential production of larvicides. Piper betle extract and chloroform extract of Tarenna asiatica reported the most significant larvicidal activity (LC50 < 1 ppm) against mosquito vectors. Further reviews focusing on the mode of actions of its phytochemically constituents are essential for the future development of potentially significant plant-based larvicides.

Matched MeSH terms: Aedes*
Limited Effect of Ground Floor Fogging on Mosquito Distribution in High-Rise Condominia

Lee JM, Wasserman RJ, Wilson RF, Cuthbert RN, Rahman S, Yek SH

Ecohealth, 2023 Mar;20(1):65-73.
PMID: 37129695 DOI: 10.1007/s10393-023-01629-8

Fogging with insecticides is one of the main control measures for adult mosquito populations employed in countries that are affected by dengue. In many such countries, urban communities are increasingly characterised by high-density residence in high-rise condominia. Although fogging is typically applied at the ground level, its efficacy in three-dimensional urban environments is poorly understood. Here, we investigated the effect of fogging on vector mosquito distribution and abundance in high-rise condominia by conducting a before-after fogging survey. We showed that although mosquitoes were significantly concentrated at the lower levels in high-rise condominia, they were found throughout the three-dimensional environments. Fogging did not significantly alter this distribution or abundance pattern across any floor level. Thus, any fogging effect was short-lived as mosquito populations recovered within a few days before the subsequent scheduled treatment. In addition, increasing fogging frequency within practicable limits did not prolong the intended control effect. As urban mosquitoes are increasingly insusceptible to fogging due to insecticide resistance and vertical avoidance, this study demonstrates the need to implement other mosquito control strategies for high-rise condominia to manage mosquito populations.

Matched MeSH terms: Aedes*
Fulltext Profiling Insecticide Susceptibility of Aedes Albopictus From Hot Springs in Selangor, Malaysia

Wan-Norafikah O, Hasani NAH, Nabila AB, Najibah I, Nurjuani AHH, Masliana M, et al.

J Am Mosq Control Assoc, 2023 Sep 01;39(3):183-191.
PMID: 37796735 DOI: 10.2987/23-7125

The present study establishes insecticide susceptibility profiles of Aedes albopictus adult populations from 4 hot springs in Selangor, Malaysia, against 7 pyrethroids through an adult mosquito susceptibility bioassay. All Ae. albopictus populations were subjected to a 1-h exposure to each pyrethroid following the World Health Organization. The mortalities were recorded at 60 min of exposure to bifenthrin, 30 min for other pyrethroids, and 24 h posttreatment for all pyrethroids. Complete mortalities were observed upon exposures to the pyrethroids under 60 min and at 24 h posttreatment, excluding permethrin 0.25%, alpha-cypermethrin 0.05%, and bifenthrin 0.2%. These findings indicated that permethrin, deltamethrin, lambda-cyhalothrin, cyfluthrin, and etofenprox possess the recommended pyrethroid adulticide active ingredients that could be applied in vector control programs at these hot springs in the future. Nevertheless, the application of pyrethroids should be carefully monitored in rotation with other insecticide classes, including organophosphates and carbamates to avoid the development of insecticide resistance among mosquito vectors towards all insecticides. Although there were no reported cases of Aedes-borne pathogens at these hot springs to date, the current study results could still assist the Malaysian health authorities in determining approaches to control Aedes populations in these hot springs, if required in the future.

Matched MeSH terms: Aedes*
Dengue virus infection and neurological manifestations: an update

Fong SL, Wong KT, Tan CT

Brain, 2024 Mar 01;147(3):830-838.
PMID: 38079534 DOI: 10.1093/brain/awad415

Dengue virus is a flavivirus transmitted by the mosquitoes, Aedes aegypti and Aedes albopictus. Dengue infection by all four serotypes (DEN 1 to 4) is endemic globally in regions with tropical and subtropical climates, with an estimated 100-400 million infections annually. Among those hospitalized, the mortality is about 1%. Neurological involvement has been reported to be about 5%. The spectrum of neurological manifestations spans both the peripheral and central nervous systems. These manifestations could possibly be categorized into those directly related to dengue infection, i.e. acute and chronic encephalitis, indirect complications leading to dengue encephalopathy, and post-infectious syndrome due to immune-mediated reactions, and manifestations with uncertain mechanisms, such as acute transverse myelitis, acute cerebellitis and myositis. The rising trend in global dengue incidence calls for attention to a more explicit definition of each neurological manifestation for more accurate epidemiological data. The actual global burden of dengue infection with neurological manifestation is essential for future planning and execution of strategies, especially in the development of effective antivirals and vaccines against the dengue virus. In this article, we discuss the recent findings of different spectrums of neurological manifestations in dengue infection and provide an update on antiviral and vaccine development and their challenges.

Matched MeSH terms: Aedes*
Hybridization between Aedes aegypti and Aedes albopictus in Malaysia

Thomas V, Yap PL

Southeast Asian J Trop Med Public Health, 1973 Jun;4(2):226-30.
PMID: 4749074
Matched MeSH terms: Aedes*
Fulltext Resistance patterns in DDT-resistant Aedes aegypti

Busvine JR, Coker WZ

Bull World Health Organ, 1958;18(4):651-6.
PMID: 13536807

Colonies of three strains of Aëdes aegypti resistant to DDT were obtained from Trinidad, Haiti and Malaya and reared beside a normal colony. From their relative resistance to a series of compounds analogous to DDT, characteristic resistance "spectra" were obtained. The two colonies from the West Indies showed a similar type of resistance, rather different from the (smaller) resistance of the Malay strain. No resistance to methoxychlor or dieldrin was found.

Matched MeSH terms: Aedes*
Fulltext The biology and demographic parameters of Aedes albopictus in northern peninsular Malaysia

Aida HN, Dieng H, Ahmad AH, Satho T, Nurita AT, Salmah MR, et al.

Asian Pac J Trop Biomed, 2011 Dec;1(6):472-7.
PMID: 23569816 DOI: 10.1016/S2221-1691(11)60103-2

OBJECTIVE: To generate life table characteristics for the dengue vector Aedes albopictus (A. albopictus) under uncontrolled conditions, incorporating both the aquatic and the adult stages.
METHODS: Ten females derived from wild pupae were allowed to fully blood-feed on restrained mice. 774 eggs were hatched in seasoned water. F1 larvae were followed for development until their F2 counterparts emerged as adults. Some population parameters were monitored (F1) or estimated (F2).
RESULTS: A. albopictus exhibited increased fecundity and egg hatch success. Immature development was quick. Immature survival was high, with lowest rate in the pupal stage. Adult emergence was about 81% and sex ratio was close to 1:1. Generational mortality (K) was about 28%. A high proportion of females completed a reproductive cycle and the obtained parity rate was predicted to lead to higher fecundity in the next generation.
CONCLUSIONS: It can be concluded that natural A. albopictus populations in Penang seem largely determined by quick development in combination with low immature loss and increased oviposition.

Matched MeSH terms: Aedes/growth & development*; Aedes/physiology
The effects of moisture on ovipositional responses and larval eclosion of Aedes albopictus

Saifur RG, Dieng H, Hassan AA, Satho T, Miake F, Boots M, et al.

J Am Mosq Control Assoc, 2010 Dec;26(4):373-80.
PMID: 21290932

Moisture plays a major role in the dynamics of mosquito populations, especially those breeding in container habitats. Despite this importance, the role of moisture conditions as they affect oviposition and egg development in Aedes vectors remains largely unexplored. We investigated the effect of exposing gravid female Aedes albopictus mosquitoes and their eggs to different moisture levels (MLs) for various periods on oviposition and hatching. Overall, high-moisture substrates (HMSs; 66% and 72%) provided better environments for egg laying. The timing of initial egg laying was far longer at the lowest substrate moisture level (LSML, 25% and 41.2%) than at HMSs. The numbers of eggs laid were much lower in the drier environments. At LSMLs, gravid females retained increasing numbers of mature eggs until death, and egg retention decreased gradually with increasing ML. The HMSs also provided better environments for larval eclosion. The numbers of eggs hatched were lower at the LSML than the HSML environment. No egg hatching occurred after 1 h exposure to moisture. However, egg hatching occurred by installment, with spontaneous hatching (SH) increasing gradually with increasing ML. High-moisture conditions combined with long exposure (30 h and 48 h) favored SH. These results suggest that Ae. albopictus females can respond to better moisture conditions for increased success of embryonation and larval eclosion. This information may be useful in the colonization of floodwater Aedes species.

Matched MeSH terms: Aedes/embryology; Aedes/physiology*
Reducing the overwintering ability of Aedes albopictus by male release

Hanson SM, Mutebi JP, Craig GB, Novak RJ

J Am Mosq Control Assoc, 1993 Mar;9(1):78-83.
PMID: 8468578

Eggs of temperate Aedes albopictus populations are cold hardy and can diapause, but tropical populations are not cold hardy and cannot diapause. Heterozygotes possess intermediate diapause and cold hardiness. Males of a tropical strain from Malaysia with a distinctive genetic marker were released into an existing temperate population in East St. Louis, Illinois. Subsequent egg samples from the release site had genetic marker frequency of up to 24%. Reduced cold hardiness and decreased diapause incidence were also observed in the release site population. No such changes occurred at a nearby control site. The rank order of overwintering survival of eggs at the release site was: Aedes triseriatus > temperate Ae. albopictus > hybrid temperate/tropical Ae. albopictus > tropical Ae. albopictus. Eggs collected from the release population the next summer showed total absence of the genetic marker; presumably carriers were removed by the winter.

Matched MeSH terms: Aedes/genetics*; Aedes/physiology
Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors

Marcela P, Hassan AA, Hamdan A, Dieng H, Kumara TK

J Am Mosq Control Assoc, 2015 Dec;31(4):313-20.
PMID: 26675452 DOI: 10.2987/moco-31-04-313-320.1

Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs.

Matched MeSH terms: Aedes/genetics; Aedes/physiology*
Fulltext Dengue vector surveillance in insular settlements of Pulau Ketam, Selangor, Malaysia

Lim KW, Sit NW, Norzahira R, Sing KW, Wong HM, Chew HS, et al.

Trop Biomed, 2010 Aug;27(2):185-92.
PMID: 20962714 MyJurnal

A year-long ovitrap surveillance was conducted between November 2007 and October 2008 in two insular settlements (Kampung Pulau Ketam and Kampung Sungai Lima) within the Malaysian island of Pulau Ketam. Eighty standard ovitraps were placed indoors and outdoors of randomly selected houses/locations. Results demonstrated an endemic baseline Aedes population throughout the year without weekly large fluctuations. Kampung Pulau Ketam has high Aedes aegypti and Aedes albopictus population, but only Ae. aegypti was found in Kampung Sungai Lima. Aedes aegypti showed no preference for ovitraps placed indoor versus outdoor. However, as expected, significantly more outdoor ovitraps were positive for Ae. albopictus (p<0.05). Trends in Ae. albopictus and Ae. aegypti populations mirrored each other suggesting that common factors influenced these two populations.

Matched MeSH terms: Aedes/physiology*; Aedes/virology*

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