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Studies on Japanese encephalitis vector mosquitoes in Selangor, Malaysia

Vythilingam I, Singh KI, Mahadevan S, Zaridah MS, Ong KK, Abidin MH

J Am Mosq Control Assoc, 1993 Dec;9(4):467-9.
PMID: 8126485

Mosquito collections were carried out from May to June 1992 and from September to December 1992 in an area where a case of Japanese encephalitis was confirmed. A total of 40,072 mosquitoes belonging to 35 species and 8 genera were collected. The dominant species in that locality were Culex vishnui, Culex tritaeniorhynchus, Culex pseudovishnui, Culex gelidus, Aedes butleri, and Mansonia uniformis.

Matched MeSH terms: Insect Vectors/microbiology*
Fulltext Oviposition deterring and oviciding potentials of Ipomoea cairica L. leaf extract against dengue vectors

Ahbirami R, Zuharah WF, Yahaya ZS, Dieng H, Thiagaletchumi M, Fadzly N, et al.

Trop Biomed, 2014 Sep;31(3):456-65.
PMID: 25382472

Bioprospecting of plant-based insecticides for vector control has become an area of interest within the last two decades. Due to drawbacks of chemical insecticides, phytochemicals of plant origin with mosquito control potential are being utilized as alternative sources in integrated vector control. In this regard, the present study aimed to investigate oviposition deterring and oviciding potentials of Ipomoea cairica (L.) (Family: Convolvulaceae) crude leaf extract against dengue vectors, Aedes aegypti and Aedes albopictus. Ipomoea cairica is an indigenous plant that has demonstrated marked toxicity towards larvae of Ae. aegypti and Ae. albopictus. Leaves of I. cairica were extracted using Soxhlet apparatus with acetone as solvent. Oviposition deterrent activity and ovicidal assay was carried out in oviposition site choice tests with three different concentrations (50, 100, 450 ppm). Acetone extract of I. cairica leaf strongly inhibited oviposition with 100% repellence to Ae. aegypti at lower concentration of 100 ppm, while for Ae. albopictus was at 450 ppm. The oviposition activity index (OAI) values which ranged from -0.69 to -1.00 revealed that I. cairica demonstrated deterrent effect. In ovicidal assay, similar trend was observed whereby zero hatchability was recorded for Ae. aegypti and Ae. albopictus eggs at 100 and 450 ppm, respectively. It is noteworthy that I. cairica leaf extract had significantly elicited dual properties as oviposition deterrent and oviciding agent in both Aedes species. Reduction in egg number through oviposition deterring activity, reduction in hatching percentage and survival rates, suggested an additional hallmark of this plant to be integrated in Aedes mosquito control. Ipomoea cairica deserved to be considered as one of the potential alternative sources for the new development of novel plant based insecticides in future.

Matched MeSH terms: Insect Vectors*
Species composition of adult Anopheles populations and their breeding habitats in Hulu Perak district, Peninsular Malaysia

Rahman WA, Adanan CR, Abu Hassan A

Southeast Asian J. Trop. Med. Public Health, 2002 Sep;33(3):547-50.
PMID: 12693589

Using the cow-baited trap (CBT) method, 1,845 Anopheles mosquitos, comprising 14 species, were caught in malaria-endemic area of Hulu Perak district, Peninsular Malaysia. The two dominant species were An. barbirostris (18.59%) and An. aconitus (18.86%). Anopheles maculatus, the main malaria vector, constituted 9.11% of the total number of mosquitos sampled. Three hundred and seventy-seven Anopheles larvae, comprising 8 species, were sampled using the North Carolina Biological Station dipper. Anopheles barbirostris larvae amounted to 64.69% of the total number of larvae; An. aconitus accounted for 10.65% of larvae. Seven habitats were identified as breeding places of Anopheles. Most species were found to breed in paddies, fishponds, and rivers. Other less popular habitats were temporary pools, mountain streams, and spring wells.

Matched MeSH terms: Insect Vectors/parasitology*; Insect Vectors/physiology*
Fulltext Indoor-breeding of Aedes albopictus in northern peninsular Malaysia and its potential epidemiological implications

Dieng H, Saifur RG, Hassan AA, Salmah MR, Boots M, Satho T, et al.

PLoS One, 2010;5(7):e11790.
PMID: 20668543 DOI: 10.1371/journal.pone.0011790

The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities.

Matched MeSH terms: Insect Vectors/physiology; Insect Vectors/virology
Distribution and dynamics of Wolbachia infection in Malaysian Aedes albopictus

Joanne S, Vythilingam I, Yugavathy N, Leong CS, Wong ML, AbuBakar S

Acta Trop, 2015 Aug;148:38-45.
PMID: 25899523 DOI: 10.1016/j.actatropica.2015.04.003

Wolbachia are maternally transmitted bacteria found in most arthropods and nematodes, but little is known about their distribution and reproductive dynamics in the Malaysian dengue vector Aedes albopictus. In this study, polymerase chain reaction (PCR) was used to determine the presence of Wolbachia from field collected Ae. albopictus from various parts of the country using wsp specific primers. Ae. albopictus had Wolbachia infection ranging from 60 to 100%. No sequence diversity of wsp gene was found within all wAlbA and wAlbB sequences. Our findings suggest that Wolbachia infection amongst the Malaysian Ae. albopictus were not homogenously distributed in all districts in Malaysia. The presence of Wolbachia in different organs of Ae. albopictus was also determined. Wolbachia were only found in the ovaries and midguts of the mosquitoes, while absent in the salivary glands. The effects of Wolbachia on Ae. albopictus fecundity, longevity and egg viability were studied using infected and uninfected colonies. The removal of Wolbachia from Ae. albopictus resulted in reduced fecundity, longevity and egg viability, thus. Wolbachia seem to play a vital role in Ae. albopictus reproductive system.

Matched MeSH terms: Insect Vectors/microbiology*
Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes

Joanne S, Vythilingam I, Teoh BT, Leong CS, Tan KK, Wong ML, et al.

Trop Med Int Health, 2017 09;22(9):1154-1165.
PMID: 28653334 DOI: 10.1111/tmi.12918

OBJECTIVE: To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes.
METHODS: Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries.
RESULTS: Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4.
CONCLUSION: Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status.

Matched MeSH terms: Insect Vectors*
Updates on chikungunya epidemiology, clinical disease, and diagnostics

Sam IC, Kümmerer BM, Chan YF, Roques P, Drosten C, AbuBakar S

Vector Borne Zoonotic Dis, 2015 Apr;15(4):223-30.
PMID: 25897809 DOI: 10.1089/vbz.2014.1680

Chikungunya virus (CHIKV) is an Aedes-borne alphavirus, historically found in Africa and Asia, where it caused sporadic outbreaks. In 2004, CHIKV reemerged in East Africa and spread globally to cause epidemics, including, for the first time, autochthonous transmission in Europe, the Middle East, and Oceania. The epidemic strains were of the East/Central/South African genotype. Strains of the Asian genotype of CHIKV continued to cause outbreaks in Asia and spread to Oceania and, in 2013, to the Americas. Acute disease, mainly comprising fever, rash, and arthralgia, was previously regarded as self-limiting; however, there is growing evidence of severe but rare manifestations, such as neurological disease. Furthermore, CHIKV appears to cause a significant burden of long-term morbidity due to persistent arthralgia. Diagnostic assays have advanced greatly in recent years, although there remains a need for simple, accurate, and affordable tests for the developing countries where CHIKV is most prevalent. This review focuses on recent important work on the epidemiology, clinical disease and diagnostics of CHIKV.

Matched MeSH terms: Insect Vectors/virology*
Discarded cigarette butts attract females and kill the progeny of Aedes albopictus

Dieng H, Saifur RG, Ahmad AH, Rawi CS, Boots M, Satho T, et al.

J Am Mosq Control Assoc, 2011 Sep;27(3):263-71.
PMID: 22017091

Discarded cigarette butts (DCB) waste occurs worldwide, pollutes landscapes, is unsightly, and results in added debris removal costs. There is, therefore, a great deal of current interest in making use of DCBs in beneficial ways. Despite evidence that DCBs are harmful to water fleas (Daphnia magna), which breed in aquatic environments as do mosquito larvae, their impact on dengue vectors is unknown. We examined whether Aedes albopictus alters its ovipositional responses, larval eclosion, and development in response to presence of DCBs in its habitats. We found oviposition activity in DCB-treated water similar to that of control water and that ovipositional activity in DCB solutions steadily increased over time as those solutions aged to 10 days. Larval eclosion was initially suppressed on day 1 in DCB solution, but increased thereafter to levels similar to control larval eclosion rates. The DCB-water solutions produced significantly higher mortality in both 1st and 2nd instars over control larvae for several days after initial exposure. Mortality rates decreased sharply 3 to 5 days postexposure as DCBs continued to decompose. We found increased survival rates during late development, but daily input of fresh DCBs prevented most young larvae from completing development. Taken together, these observations suggest that decomposing did not deter gravid Ae. albopictus females from ovipositing in treated containers and that DCB solutions had larvicidal effects on early instars. Our results are discussed in the context of DCB use to control container-breeding Ae. albopictus, a competent dengue vector in Asia and other parts of the world.

Matched MeSH terms: Insect Vectors
Seasonality of Anopheles aconitus mosquitoes, a secondary vector of malaria, in an endemic village near the Malaysia-Thailand border

Rahman WA, Abu Hassan A, Adanan CR

Acta Trop, 1993 Dec;55(4):263-5.
PMID: 8147283
Matched MeSH terms: Insect Vectors*
Indoor thermal fogging application of pesguard FG 161, a mixture of d-tetramethrin and cyphenothrin, using portable sprayer against vector mosquitoes in the tropical environment

Yap HH, Lee YW, Zairi J, Jahangir K, Adanan CR

J Am Mosq Control Assoc, 2001 Mar;17(1):28-32.
PMID: 11345415

Indoor bioefficacy of the thermal fogging application of Pesguard FG 161, a formulation containing both knockdown and killing agents (active ingredient [AI]: d-tetramethrin 4% [w/w] and cyphenothrin 12% [w/w]) was compared with Resigen5 (AI: s-bioallethrin 0.8% [w/w], permethrin 125/75] 18.7% [w/w], and piperonyl butoxide 16.8% [w/w]), another pyrethroid formulation, as larvicides and adulticides against Aedes aegypti, Aedes albopictus, Anopheles sinensis, and Culex quinquefasciatus using a portable Agrofog AF35 sprayer indoors in houses on Penang Island, Malaysia. Pesguard FG 161 at the concentrations tested was effective against all 4 mosquito species tested. The water-based Pesguard FG 161 performed far better as a larvicide than the diesel-based formulation. Resigen was also effective as a larvicide and adulticide against all 4 mosquito species tested. Larvae of Ae. aegypti were most susceptible to water-based Pesguard FG 161, followed by Cx. quinquefasciatus, An. sinensis, and Ae. albopictus. Even at the lowest concentrations tested, Pesguard FG 161 showed adequate adulticidal properties. At higher dosages, water-based Pesguard FG 161 proved effective as a larvicide against all 4 mosquito species.

Matched MeSH terms: Insect Vectors
Composition and biting activity of Anopheles (Diptera: Culicidae) attracted to human bait in a malaria endemic village in peninsular Malaysia near the Thailand border

Hassan AA, Rahman WA, Rashid MZ, Shahrem MR, Adanan CR

J Vector Ecol, 2001 Jun;26(1):70-5.
PMID: 11469187

Nine species of Anopheles mosquitoes were collected biting humans indoors and outdoors in a malaria endemic village in northern Peninsular Malaysia. Outdoor biting was higher than that observed indoors. Biting of An. maculatus was observed throughout the night. Peak indoor biting occurred at 2130 h while outdoor biting was higher after midnight. Outdoor biting of Anopheles barbirostris and An. sinensis was observed throughout the night with several peaks after the second half of the night. Outdoor biting activities of An. kochi and An. philippinensis were primarily active after dusk and steadily declined after 2130 h.

Matched MeSH terms: Insect Vectors*
Genetic diversity and DNA barcoding of the black fly (Diptera: Simuliidae) vectors of parasites causing human onchocerciasis in Guatemala

Pramual P, Bunchom N, Saijuntha W, Tada I, Suganuma N, Agatsuma T

Trop Biomed, 2019 Dec 01;36(4):938-957.
PMID: 33597465

Genetic variation based on mitochondrial cytochrome c oxidase I (COI) and II (COII) sequences was investigated for three black fly nominal species, Simulium metallicum Bellardi complex, S. callidum Dyar and Shannon, and S. ochraceum Walker complex, which are vectors of human onchocerciasis from Guatemala. High levels of genetic diversity were found in S. metallicum complex and S. ochraceum complex with maximum intraspecific genetic divergences of 11.39% and 4.25%, respectively. Levels of genetic diversity of these nominal species are consistent with species status for both of them as they are cytologically complexes of species. Phylogenetic analyses revealed that the S. metallicum complex from Guatemala divided into three distinct clades, two with members of this species from several Central and South American countries and another exclusively from Mexico. The Simulium ochraceum complex from Guatemala formed a clade with members of this species from Mexico and Costa Rica while those from Ecuador and Colombia formed another distinct clade. Very low diversity in S. callidum was found for both genes with maximum intraspecific genetic divergence of 0.68% for COI and 0.88% for COII. Low genetic diversity in S. callidum might be a consequence of the result being informative of only recent population history of the species.

Matched MeSH terms: Insect Vectors/genetics; Insect Vectors/parasitology
Fulltext Malaria and Anopheles mosquitos in Malaysia

Rahman WA, Che'Rus A, Ahmad AH

Southeast Asian J. Trop. Med. Public Health, 1997 Sep;28(3):599-605.
PMID: 9561615

Until today, malaria is still one of the most important diseases in Malaysia. This is because Malaysia is located within the equatorial zone with high temperatures and humidities, usually important for the transmission of malaria. The number of malaria cases were estimated to be around 300,000 before the launching of the Malaria Eradication Program (MEP). The program was successful in reducing the numbers progressively during the 1967-1982 period. During the period 1980-1991, the highest number of malaria cases recorded for the country was 65,283 in 1989 (16,902 in Peninsular Malaysia, 47,545 in Sabah and 836 in Sarawak) whilst the lowest was 22,218 (10,069 in Peninsular Malaysia, 11,290 in Sabah and 859 in Sarawak) in 1983. In Malaysia, there are 434 species of mosquitos, representing 20 genera. Of these, 75 species are Anopheles that comprise of 2 subgenus, i.e. Anopheles and Cellia. Of the 75 species, only 9 have been reported as vectors: An. maculatus, An balabacensis, An. dirus, An. letifer An. campestris, An. sundaicus, An. donaldi, An. leucophyrus and An. flavirostris. The behavior, seasonal abundance, biting activities and breeding sites of these species are discussed.

Matched MeSH terms: Insect Vectors/classification; Insect Vectors/parasitology*; Insect Vectors/physiology
Fulltext Effect of sublethal dosages of malathion on the oral susceptibility of Aedes aegypti to dengue-2 virus infection

Lee HL, Argubano RA, Ahmad R

Southeast Asian J. Trop. Med. Public Health, 1997 Sep;28(3):664-5.
PMID: 9561626
Matched MeSH terms: Insect Vectors/virology*
Fulltext Knowledge and attitude towards cutaneous leishmaniasis among rural endemic communities in Shara'b district, Taiz, southwestern Yemen

Alharazi TH, Haouas N, Al-Mekhlafi HM

BMC Infect Dis, 2021 Mar 17;21(1):269.
PMID: 33731042 DOI: 10.1186/s12879-021-05965-4

BACKGROUND: Cutaneous leishmaniasis (CL), a neglected tropical disease, represents a significant public health problem in many endemic countries including Yemen. The ongoing armed conflict that started in March 2015 has had a negative impact on the entire healthcare system as well as on infectious disease control programmes. Therefore, this cross-sectional study aimed to assess knowledge and attitude towards CL among rural endemic communities in southwestern Yemen.
METHODS: Five hundred households in five areas of Shara'b district of Taiz governorate were randomly selected to participate in a quantitative survey. A pretested structured questionnaire was used to collect data on the sociodemographic characteristics of the participants, their knowledge and attitude towards CL and their knowledge on the sand fly vector.
RESULTS: The analysis was conducted on a final sample of 466 individuals (62.7% males and 37.3% females) aged between 18 and 70 years. Among the participants, 21.5% were non-educated while 39.7 and 20.8% had completed secondary school and tertiary education, respectively. Although the participants were aware of CL, about three quarters (77.7%) of them had poor overall knowledge about disease transmission, clinical presentation, treatment, and prevention. Interestingly, approximately half of the participants (49.1%) were able to differentiate sand flies from other flies and mosquitoes. However, only 14.8% of the participants knew about the role of the phlebotomine sand fly in the transmission of CL. Only 36.6% believed that CL can be prevented and 49.6% had a negative attitude towards the disease. Univariate and multivariate analyses showed that age and gender were the significant determinants of knowledge about CL and the sand fly vector among the studied population.
CONCLUSION: A poor level of knowledge about the different epidemiological aspects of CL was found among rural CL-endemic communities in Taiz. This factor, together with the major collapse of the healthcare infrastructure due to the ongoing civil war in Yemen, may be contributing to the continued endemicity of CL in the governorate. It is therefore recommended that health education on CL transmission and prevention should be provided to the targeted communities.

Matched MeSH terms: Insect Vectors/physiology
Fulltext A spatio-temporal agent-based approach for modeling the spread of zoonotic cutaneous leishmaniasis in northeast Iran

Tabasi M, Alesheikh AA, Sofizadeh A, Saeidian B, Pradhan B, AlAmri A

Parasit Vectors, 2020 Nov 11;13(1):572.
PMID: 33176858 DOI: 10.1186/s13071-020-04447-x

BACKGROUND: Zoonotic cutaneous leishmaniasis (ZCL) is a neglected tropical disease worldwide, especially the Middle East. Although previous works attempt to model the ZCL spread using various environmental factors, the interactions between vectors (Phlebotomus papatasi), reservoir hosts, humans, and the environment can affect its spread. Considering all of these aspects is not a trivial task.
METHODS: An agent-based model (ABM) is a relatively new approach that provides a framework for analyzing the heterogeneity of the interactions, along with biological and environmental factors in such complex systems. The objective of this research is to design and develop an ABM that uses Geospatial Information System (GIS) capabilities, biological behaviors of vectors and reservoir hosts, and an improved Susceptible-Exposed-Infected-Recovered (SEIR) epidemic model to explore the spread of ZCL. Various scenarios were implemented to analyze the future ZCL spreads in different parts of Maraveh Tappeh County, in the northeast region of Golestan Province in northeastern Iran, with alternative socio-ecological conditions.
RESULTS: The results confirmed that the spread of the disease arises principally in the desert, low altitude areas, and riverside population centers. The outcomes also showed that the restricting movement of humans reduces the severity of the transmission. Moreover, the spread of ZCL has a particular temporal pattern, since the most prevalent cases occurred in the fall. The evaluation test also showed the similarity between the results and the reported spatiotemporal trends.
CONCLUSIONS: This study demonstrates the capability and efficiency of ABM to model and predict the spread of ZCL. The results of the presented approach can be considered as a guide for public health management and controlling the vector population .

Matched MeSH terms: Insect Vectors/parasitology
Genetically modified mosquitoes

Aldridge S

Nat Biotechnol, 2008 Jul;26(7):725.
PMID: 18612284 DOI: 10.1038/nbt0708-725a
Matched MeSH terms: Insect Vectors/genetics*
Fulltext The impact of insecticides and plant extracts on the suppression of insect vector (Bemisia tabaci) of Mungbean yellow mosaic virus (MYMV)

Younas M, Zou H, Laraib T, Rajpoot NA, Khan NA, Zaidi AA, et al.

PLoS One, 2021;16(9):e0256449.
PMID: 34529693 DOI: 10.1371/journal.pone.0256449

Mungbean yellow mosaic virus (MYMV) is an important constraint in successful production of mungbean (Vigna radiata L.) in many countries, including Pakistan. The MYMV spreads by insect vector whitefly (Bemisia tabaci Gennadius). The use of resistant cultivars is the most effective management tactics for MYMV. Twenty mungbean varieties/lines were screened against insect vector of MYMV under field condition in the current study. Resistance levels for varieties/lines were assessed through visual scoring of typical disease symptoms. Furthermore, the impacts of two insecticides 'Imidacloprid' and 'Thiamethoxam' and two plant extracts, i.e., neem (Azadirachta indica), and Eucalyptus (Eucalyptus camaldulensis) were tested on the suppression of whitefly. Field screening indicated that none of the tested varieties/lines proved immune/highly resistant, while significant variations were recorded among varieties/lines for resistance level. All varieties/lines were systemically infected with MYMV. The varieties 'AARI-2006' and 'Mung-14043' were considered as resistant to MYMV based on visual symptoms and the lowest vector population. These varieties were followed by 'NM-2006' and 'NL-31', which proved as moderately resistant to MYMV. All remaining varieties/lines were grouped as moderately to highly susceptible to MYMV based on visual symptoms' scoring. These results revealed that existing mungbean germplasm do not possess high resistance level MYMV. However, the lines showing higher resistance in the current study must be exploited in breeding programs for the development of resistant mungbean varieties/lines against MYMV. Imidacloprid proved as the most effective insecticide at all concentrations to manage whitefly population. Therefore, use of the varieties with higher resistance level and spraying Imidacloprid could lower the incidence of MYMV.

Matched MeSH terms: Insect Vectors/drug effects*
Population cytogenetics of the malaria vector Anopheles leucosphyrus group

Baimai V

Southeast Asian J. Trop. Med. Public Health, 1988 Dec;19(4):667-80.
PMID: 3238480

Until recently, very little was known of Anopheles species complexes and their relationships to epidemiology and malaria transmission in Southeast Asia. During the past eight years, extensive studies on the genetics of natural populations of anopheline mosquitoes in this region, involving the interdisciplinary efforts of taxonomists, operational entomologists and biologists, have revealed groups of cryptic species of Anopheles vectors, particularly the An. leucos phyrus group. This species group comprise seventeen species and two subspecies widely distributed in the forested areas of Southeast Asia. Among these species. An. dirus Peyton and Harrison, has been shown by cytogenetic and morphological studies to be a complex of at least seven isomorphic species, provisionally designated species A, B, C, D, E, F and takasagoensis, on the Southeast Asian mainland. Cytological identification of these species is based on distinct banding patterns of salivary gland polytene chromosomes as well as heterochromatin differences in mitotic karyotypes. The five species found in Thailand (A-D, F) exhibit distinct geographic distributions. Species A is widespread throughout Thailand except in the south. Species B had been found in sympatry with species C in southern Thailand and both seem to show north-south clinal geographic variation. Species D is common on the west side of southern Thailand and along the Thai-Burmese border in sympatry with species A. Species F, An. nemophilous Peyton and Ramalingam, has been found in a population at the Thai-Malaysian border in this study although it was known to be common in southern and western Thailand and Peninsular Malaysia. Species E is known only from western India. The five species found in Thailand also exhibit seasonal variation in relative abundance and different nocturnal biting cycles. Chromosomal polymorphisms have been observed in mitotic and polytene chromosomes of An. dirus A and D. Species B and C also show heterochromatin variation in the sex chromosomes, but are monomorphic for the standard sequence in polytene chromosomes. These biological characteristics of the An. dirus complex may have implications for understanding the epidemiology of malaria in Southeast Asia. Recent cytogenetic studies of wild-caught samples of An. leucosphyrus from Sumatra, Kalimantan and southern Thailand have revealed the presence of two distinct species within this taxon. Species A is widely distributed in southern Thailand, East Malaysia and Kalimantan, while species B is confined to Sumatra. The two isomorphic species are vectors of human malaria within their range of distribution.(ABSTRACT TRUNCATED AT 400 WORDS)

Matched MeSH terms: Insect Vectors/genetics*
Blackfly vectors of zoonotic onchocerciasis in Japan

Takaoka H, Fukuda M, Otsuka Y, Aoki C, Uni S, Bain O

Med Vet Entomol, 2012 Dec;26(4):372-8.
PMID: 22827756 DOI: 10.1111/j.1365-2915.2012.01023.x

Studies of blackfly vectors of Onchocerca dewittei japonica Uni, Bain & Takaoka (Spirurida: Onchocercidae), a parasite of wild boar implicated in the aetiology of zoonotic onchocerciasis in Japan, and six other zoonotic Onchocerca species of this country are reviewed. Molecular identification of infective larvae found in wild-caught female blackflies showed that Simulium bidentatum (Shiraki) (Diptera: Simuliidae) is a natural vector of O. dewittei japonica, and also Onchocerca sp. sensu Fukuda et al., another parasite of wild boar. Inoculation experiments demonstrated that Simulium arakawae Matsumura and four other Simulium species are putative vectors. Similarly, S. arakawae, S. bidentatum and Simulium oitanum (Shiraki) are putative vectors of Onchocerca eberhardi Uni & Bain and Onchocerca skrjabini Rukhlyadev, parasites of sika deer. Morphometric studies of infective larvae indicated that Onchocerca lienalis Stiles, a bovine species, is transmitted by S. arakawae, Simulium daisense (Takahasi) and Simulium kyushuense Takaoka, and that Onchocerca sp. sensu Takaoka & Bain, another bovine species, is transmitted by S. arakawae, S. bidentatum, S. daisense and S. oitanum. Prosimulium sp. (Diptera: Simuliidae) and Simulium japonicum Matsumura are suspected vectors of Onchocerca suzukii Yagi, Bain & Shoho and O. skrjabini [Twinnia japonensis Rubtsov (Diptera: Simuliidae) may also transmit the latter], parasites of Japanese serow, following detection of the parasites' DNA genes in wild-caught blackflies.

Matched MeSH terms: Insect Vectors/classification; Insect Vectors/parasitology*

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