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1

September 2012 Malaria: vector mosquitoes  

E-print Network

N° 413 September 2012 Malaria: vector mosquitoes are constantly adapting Scientific news Actualidad cientifica Actualité scientifique On the recommendations of the WHO, 290 million impregnated mosquito nets ability of the mosquitoes that carry it to adapt to pyrethrinoids, the officially recommended insecticides

2

Mapping of zones potentially occupied by Aedes vexans and Culex poicilipes mosquitoes the main vectors of Rift Valley fever in Senegal  

Microsoft Academic Search

Abstract. A necessary condition for Rift Valley fever (RVF) emergence,is the presence of Aedes (Aedimorphus) vexans and Culex (Culex) poicilipes mosquitoes,carrying the arbovirus and responsible for the infection. This paper presents a detailed mapping,in the Sahelian region of Senegal of zones potentially occupied,by these mosquitoes,(ZPOMs) whose,population density is directly linked to ecozones in the vicinity of small ponds. The vectors

Yves M. Tourre; Jean-pierre Lacaux; Cecile Vignolles; Jacques-andr Ndione; Murielle Lafaye

2008-01-01

3

Using Cell Phones for Mosquito Vector Surveillance and Control  

E-print Network

Using Cell Phones for Mosquito Vector Surveillance and Control S. Lozano-Fuentes, S. Ghosh, J. M--Novel, low-cost approaches to improving prevention and control of vector-borne diseases, such as mosquito the use of cell phones for field capture and rapid transfer of mosquito vector surveillance data

Bieman, James M.

4

ORIGINAL RESEARCH Chikungunya Virus and the Mosquito Vector  

E-print Network

ORIGINAL RESEARCH Chikungunya Virus and the Mosquito Vector Aedes aegypti in New Caledonia (South mosquitoes. During the 2005­ 2006 epidemic that occurred in the Indian Ocean Islands, a viral strain of infected Aedes species mosquitoes, particularly Aedes aegypti and Aedes albopictus. It induces an arthro

Paris-Sud XI, Université de

5

[Mosquitoes as vectors for exotic pathogens in Germany].  

PubMed

As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics. PMID:24781910

Becker, N; Krger, A; Kuhn, C; Plenge-Bnig, A; Thomas, S M; Schmidt-Chanasit, J; Tannich, E

2014-05-01

6

Repellency of Volatile Oils from Plants against Three Mosquito Vectors  

Microsoft Academic Search

Volatile oils extracted by steam distillation from four plant species turmeric (Curcuma longa), kaffir lime (Citrus hystrix), citronella grass (Cymbopogon winterianus) and hairy basil (Ocimum americanum)), were evaluated in mosquito cages and in a large room for their repellency effects against three mosquito vectors, Aedes aegypti, Anopheles dirus and Culex quinquefasciatus. The oils from turmeric, citronella grass and hairy basil,

Apiwat Tawatsin; Steve D. Wratten; R. Roderic Scott; Usavadee Thavara; Yenchit Techadamrongsin

2004-01-01

7

Harnessing mosquito-Wolbachia symbiosis for vector and disease control.  

PubMed

Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. PMID:24252486

Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Herv C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

2014-04-01

8

Mosquito surveillance in northwestern Italy to monitor the occurrence of tropical vector-borne diseases.  

PubMed

Mosquito-borne arboviruses (MBV) represent an important health problem, causing diseases and deaths both in human and animals mainly in tropical and subtropical countries. In recent years, they have emerged also in temperate regions where they have caused epidemics. Of mounting concern among public health authorities in Europe are zoonotic mosquito-borne viruses belonging to the Flavivirus genus. The aim of this study was to carry out active surveillance on mosquitoes in two regions of northwestern Italy (Liguria and Piedmont) to gain a better knowledge of the mosquito populations by identifying potential vectors of arboviruses and to investigate arbovirus infection. A network of 61 CO? CDC traps was placed in the study area; sampling was conducted from May to October 2011. A total of 46,677 mosquitoes was collected, identified to species level, and classified according to their vector competence. Mosquitoes collected from 16 traps, selected according to risk-based factors, were tested by biomolecular analysis to detect flavivirus infection. This study highlights the importance of entomological surveillance in northwestern Italy because most of the mosquitoes collected were found to have high vector competence. Moreover, the risk-based virological surveillance allowed to detect the presence of mosquito flavivirus RNA, phylogenetically closely related to the MMV Spanish isolate, in three pools and USUV RNA in one pool in new areas where it has not been reported previously. The availability of continuous data on mosquito populations provides invaluable information for use in cases of an epidemic emergency. Maintenance of this integrated system for the next years will provide stronger data that can inform the design of a risk-based surveillance for the early detection of the occurrence of outbreaks of tropical MBDs. PMID:24589116

Pautasso, A; Desiato, R; Bertolini, S; Vitale, N; Radaelli, M C; Mancini, M; Rizzo, F; Mosca, A; Calzolari, M; Prearo, M; Mandola, M L; Maurella, C; Mignone, W; Chiavacci, L; Casalone, C

2013-11-01

9

Mosquito vectors of dog heartworm in the United States: vector status and factors influencing transmission efficiency.  

PubMed

Dog heartworm (Dirofilaria immitis) is dependent on mosquito vectors for its maintenance and transmission among vertebrate hosts. Consequently, D. immitis abundance and distribution are closely linked with mosquito vector biology and ecology. Information on the important dog heartworm vectors in the United States is limited and no comprehensive surveillance of dog heartworm in US mosquitoes has been undertaken to date. Here, we review information gleaned from a number of field surveys documenting heartworm presence in wild mosquito populations as well as laboratory assessments of mosquito vector capacity. Various biological and ecological factors likely contribute to the relative importance of different vector species. We describe some of these factors, rank the leading criteria for efficient vectors, and present the most likely vector species found across the United States. Considering the recent emergence of drug resistance among D. immitis strains, practical knowledge of heartworm vector biology and control should be incorporated into heartworm disease management programs. We conclude by proposing that heartworm control would benefit by targeting mosquito vectors, and we suggest ways in which veterinarians can incorporate the recognition of vector importance into heartworm prevention recommendations imparted to clients. PMID:22152605

Ledesma, Nicholas; Harrington, Laura

2011-11-01

10

MosquitoMap and the Mal-area calculator: new web tools to relate mosquito species distribution with vector borne disease  

Microsoft Academic Search

BACKGROUND: Mosquitoes are important vectors of diseases but, in spite of various mosquito faunistic surveys globally, there is a need for a spatial online database of mosquito collection data and distribution summaries. Such a resource could provide entomologists with the results of previous mosquito surveys, and vector disease control workers, preventative medicine practitioners, and health planners with information relating mosquito

Desmond H Foley; Richard C Wilkerson; Ian Birney; Stanley Harrison; Jamie Christensen; Leopoldo M Rueda

2010-01-01

11

Japanese encephalitis on Saipan: a survey of suspected mosquito vectors.  

PubMed

An outbreak of Japanese encephalitis (JE) occurred on Saipan, Commonwealth of Northern Mariana Islands, in October 1990. Adult and larval mosquitoes were collected during September-October 1991 to retrospectively determine the probable mosquito vector(s). Virus was not isolated from 119 mosquito pools composed of 7,250 adult specimens as follows: Aedes vexans nocturnis (14%), Culex tritaeniorhynchus (39%), Cx. sitiens group (11%), Culex (Culex) species (35%), and < 1% each of Ae. albopictus, Ae. oakleyi, Aedes saipanensis, Cx. annulirostris marianae, and Cx. fuscanus. Three additional species were collected only as larvae: Anopheles indefinitus, Ae. neopandani, and Cx. quinquefasciatus. Among the vectors of JE incriminated in other areas, Cx. tritaeniorhynchus was the predominant species in our collections and the principal species feeding on swine. This is the first published record of the occurrence of this species on Saipan. Culex tritaeniorhynchus is abundant and widely distributed on the southern half of Saipan where human JE cases occurred in 1990, and where swine seroconversions were detected. Although the identity of the mosquito vector(s) responsible for the 1990 outbreak cannot be established with certainty, our results suggest that Cx. tritaeniorhychus was probably involved. PMID:8386909

Mitchell, C J; Savage, H M; Smith, G C; Flood, S P; Castro, L T; Roppul, M

1993-04-01

12

The evolution and genetics of vector competence in mosquito disease vectors  

E-print Network

Vector competence is a complex characteristic which governs an insect's ability to acquire, support the development and transmit a parasite from one host to another. It influences variation in disease transmission among mosquito populations, hence...

Osei-Poku, Jewelna

2013-03-12

13

Devising novel strategies against vector mosquitoes and house flies  

Technology Transfer Automated Retrieval System (TEKTRAN)

In 1932, the United States Department of Agriculture established an entomological research laboratory in Orlando, Florida. The initial focus of the program was on investigations of mosquitoes (including malaria vectors under conditions simulating those of South Pacific jungles) and other insects ...

14

Mosquitoes as vectors of Setaria labiatopapillosa  

Microsoft Academic Search

An infected bovinebaited trap was utilised in summer 1994 to catch possible intermediate hosts of S. labiatopapillosa in northeastern Italy. Collections were made for 21 nights from 8.00 p.m. to 6.00 a.m. every 2 h and, after 12 September, every 30 min. Among the 16 159 mosquitoes sampled, 11 052 were freshly blood-fed. Most of the unfed females and a

G. Cancrini; M. Pietrobelli; A. Frangipane di Regalbono; M. P. Tampieri

1997-01-01

15

Repellency of volatile oils from plants against three mosquito vectors.  

PubMed

Volatile oils extracted by steam distillation from four plant species (turmeric (Curcuma longa), kaffir lime (Citrus hystrix), citronella grass (Cymbopogon winterianus) and hairy basil (Ocimum americanum)), were evaluated in mosquito cages and in a large room for their repellency effects against three mosquito vectors, Aedes aegypti, Anopheles dirus and Culex quinquefasciatus. The oils from turmeric, citronella grass and hairy basil, especially with the addition of 5% vanillin, repelled the three species under cage conditions for up to eight hours. The oil from kaffir lime alone, as well as with 5% vanillin added, was effective for up to three hours. With regard to the standard repellent, deet alone provided protection for at least eight hours against Ae. aegypti and Cx. quinquefasciatus, but for six hours against An. dirus. However, deet with the addition of 5% vanillin gave protection against the three mosquito species for at least eight hours. The results of large room evaluations confirmed the responses for each repellent treatment obtained under cage conditions. This study demonstrates the potential of volatile oils extracted from turmeric, citronella grass and hairy basil as topical repellents against both day- and night-biting mosquitoes. The three volatile oils can be formulated with vanillin as mosquito repellents in various forms to replace deet (N,N-diethyl-3-methylbenzamide), the most common chemical repellent currently available. PMID:11469188

Tawatsin, A; Wratten, S D; Scott, R R; Thavara, U; Techadamrongsin, Y

2001-06-01

16

Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes.  

PubMed

Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. PMID:25554792

Neafsey, Daniel E; Waterhouse, Robert M; Abai, Mohammad R; Aganezov, Sergey S; Alekseyev, Max A; Allen, James E; Amon, James; Arc, Bruno; Arensburger, Peter; Artemov, Gleb; Assour, Lauren A; Basseri, Hamidreza; Berlin, Aaron; Birren, Bruce W; Blandin, Stephanie A; Brockman, Andrew I; Burkot, Thomas R; Burt, Austin; Chan, Clara S; Chauve, Cedric; Chiu, Joanna C; Christensen, Mikkel; Costantini, Carlo; Davidson, Victoria L M; Deligianni, Elena; Dottorini, Tania; Dritsou, Vicky; Gabriel, Stacey B; Guelbeogo, Wamdaogo M; Hall, Andrew B; Han, Mira V; Hlaing, Thaung; Hughes, Daniel S T; Jenkins, Adam M; Jiang, Xiaofang; Jungreis, Irwin; Kakani, Evdoxia G; Kamali, Maryam; Kemppainen, Petri; Kennedy, Ryan C; Kirmitzoglou, Ioannis K; Koekemoer, Lizette L; Laban, Njoroge; Langridge, Nicholas; Lawniczak, Mara K N; Lirakis, Manolis; Lobo, Neil F; Lowy, Ernesto; MacCallum, Robert M; Mao, Chunhong; Maslen, Gareth; Mbogo, Charles; McCarthy, Jenny; Michel, Kristin; Mitchell, Sara N; Moore, Wendy; Murphy, Katherine A; Naumenko, Anastasia N; Nolan, Tony; Novoa, Eva M; O'Loughlin, Samantha; Oringanje, Chioma; Oshaghi, Mohammad A; Pakpour, Nazzy; Papathanos, Philippos A; Peery, Ashley N; Povelones, Michael; Prakash, Anil; Price, David P; Rajaraman, Ashok; Reimer, Lisa J; Rinker, David C; Rokas, Antonis; Russell, Tanya L; Sagnon, N'Fale; Sharakhova, Maria V; Shea, Terrance; Simo, Felipe A; Simard, Frederic; Slotman, Michel A; Somboon, Pradya; Stegniy, Vladimir; Struchiner, Claudio J; Thomas, Gregg W C; Tojo, Marta; Topalis, Pantelis; Tubio, Jos M C; Unger, Maria F; Vontas, John; Walton, Catherine; Wilding, Craig S; Willis, Judith H; Wu, Yi-Chieh; Yan, Guiyun; Zdobnov, Evgeny M; Zhou, Xiaofan; Catteruccia, Flaminia; Christophides, George K; Collins, Frank H; Cornman, Robert S; Crisanti, Andrea; Donnelly, Martin J; Emrich, Scott J; Fontaine, Michael C; Gelbart, William; Hahn, Matthew W; Hansen, Immo A; Howell, Paul I; Kafatos, Fotis C; Kellis, Manolis; Lawson, Daniel; Louis, Christos; Luckhart, Shirley; Muskavitch, Marc A T; Ribeiro, Jos M; Riehle, Michael A; Sharakhov, Igor V; Tu, Zhijian; Zwiebel, Laurence J; Besansky, Nora J

2015-01-01

17

Interspecific transfer of Wolbachia into the mosquito disease vector Aedes albopictus  

E-print Network

Interspecific transfer of Wolbachia into the mosquito disease vector Aedes albopictus Zhiyong Xi success of Wolbachia is due in part to an ability to manipulate reproduction. In mosquitoes and many other important mosquito. Using embryonic microinjection, Wolbachia is transferred from Drosophila simulans

Dobson, Stephen L.

18

Eastern Equine Encephalitis Virus in Mosquitoes and Their Role as Bridge Vectors  

PubMed Central

Eastern equine encephalitis virus (EEEV) is maintained in an enzootic cycle involving Culiseta melanura mosquitoes and avian hosts. Other mosquito species that feed opportunistically on mammals have been incriminated as bridge vectors to humans and horses. To evaluate the capacity of these mosquitoes to acquire, replicate, and potentially transmit EEEV, we estimated the infection prevalence and virus titers in mosquitoes collected in Connecticut, USA, by cell culture, plaque titration, and quantitative reverse transcriptionPCR. Cs. melanura mosquitoes were the predominant source of EEEV (83 [68%] of 122 virus isolations) and the only species to support consistently high virus titers required for efficient transmission. Our findings suggest that Cs. melanura mosquitoes are primary enzootic and epidemic vectors of EEEV in this region, which may explain the relative paucity of human cases. This study emphasizes the need for evaluating virus titers from field-collected mosquitoes to help assess their role as vectors. PMID:21122215

Andreadis, Theodore G.

2010-01-01

19

Vector competence of Australian mosquitoes for yellow fever virus.  

PubMed

The vector competence of Australian mosquitoes for yellow fever virus (YFV) was evaluated. Infection and transmission rates in Cairns and Townsville populations of Aedes aegypti and a Brisbane strain of Ae. notoscriptus were not significantly different from a well-characterized YFV-susceptible strain of Ae. aegypti. After exposure to 10? tissue culture infectious dose (TCID??)/mL of an African strain of YFV, > 70% of Ae. aegypti and Ae. notoscriptus became infected, and > 50% transmitted the virus. When exposed to 10??) TCID??/mL of a South American strain of YFV, the highest infection (64%) and transmission (56%) rates were observed in Ae. notoscriptus. The infection and transmission rates in the Cairns Ae. aegypti were both 24%, and they were 36% and 28%, respectively, for the Townsville population. Because competent vectors are present, the limited number of travelers from endemic areas and strict vaccination requirements will influence whether YFV transmission occurs in Australia. PMID:21896802

van den Hurk, Andrew F; McElroy, Kate; Pyke, Alyssa T; McGee, Charles E; Hall-Mendelin, Sonja; Day, Andrew; Ryan, Peter A; Ritchie, Scott A; Vanlandingham, Dana L; Higgs, Stephen

2011-09-01

20

Research Paper Modeling the Spatial Distribution of Mosquito Vectors for West Nile Virus in Connecticut, USA  

Microsoft Academic Search

The risk of transmission of West Nile virus (WNV) to humans is associated with the density of infected vector mosquitoes in a given area. Current technology for estimating vector distribution and abundance is primarily based on Centers for Disease Control and Prevention (CDC) light trap collections, which provide only point data. In order to estimate mosquito abundance in areas not

MARIA A. DIUK-WASSER; HEIDI E. BROWN; THEODORE G. ANDREADIS; DURLAND FISH

21

Modeling the Spatial Distribution of Mosquito Vectors for West Nile Virus in Connecticut, USA  

Microsoft Academic Search

ABSTRACT The risk of transmission of West Nile virus (WNV) to humans is associated with the density of infected vector mosquitoes in a given area. Current technology for estimating vector distribution and abundance is primarily based on Centers for Disease Control and Prevention (CDC) light trap collections, which provide only point data. In order to estimate mosquito abundance in areas

Maria A. Diuk-Wasser; Heidi E. Brown; Theodore G. Andreadis; Durland Fish

2006-01-01

22

Bacteria of the genus Asaia stably associate with Anopheles stephensi, an Asian malarial mosquito vector  

PubMed Central

Here, we show that an ?-proteobacterium of the genus Asaia is stably associated with larvae and adults of Anopheles stephensi, an important mosquito vector of Plasmodium vivax, a main malaria agent in Asia. Asaia bacteria dominate mosquito-associated microbiota, as shown by 16S rRNA gene abundance, quantitative PCR, transmission electron microscopy and in situ-hybridization of 16S rRNA genes. In adult mosquitoes, Asaia sp. is present in high population density in the female gut and in the male reproductive tract. Asaia sp. from An. stephensi has been cultured in cell-free media and then transformed with foreign DNA. A green fluorescent protein-tagged Asaia sp. strain effectively lodged in the female gut and salivary glands, sites that are crucial for Plasmodium sp. development and transmission. The larval gut and the male reproductive system were also colonized by the transformed Asaia sp. strain. As an efficient inducible colonizer of mosquitoes that transmit Plasmodium sp., Asaia sp. may be a candidate for malaria control. PMID:17502606

Favia, Guido; Ricci, Irene; Damiani, Claudia; Raddadi, Noura; Crotti, Elena; Marzorati, Massimo; Rizzi, Aurora; Urso, Roberta; Brusetti, Lorenzo; Borin, Sara; Mora, Diego; Scuppa, Patrizia; Pasqualini, Luciano; Clementi, Emanuela; Genchi, Marco; Corona, Silvia; Negri, Ilaria; Grandi, Giulio; Alma, Alberto; Kramer, Laura; Esposito, Fulvio; Bandi, Claudio; Sacchi, Luciano; Daffonchio, Daniele

2007-01-01

23

Monitoring of larval habitats and mosquito densities in the Sudan savanna of Mali: implications for malaria vector control.  

PubMed

In Mali, anopheline mosquito populations increase sharply during the rainy season, but are barely detectable in the dry season. This study attempted to identify the dry season mosquito breeding population in and near the village of Bancoumana, Mali, and in a fishing hamlet 5 km from this village and adjacent to the Niger River. In Bancoumana, most larval habitats were human made, and dried out in January-February. In contrast, in the fishing hamlet, productive larval habitats were numerous and found mainly during the dry season (January-May) as the natural result of drying riverbeds. Adult mosquitoes were abundant during the dry season in the fishermen hamlet and rare in Bancoumana. To the extent that the fishermen hamlet mosquito population seeds Bancoumana with the advent of the rainy season, vector control in this small hamlet may be a cost-effective way to ameliorate malaria transmission in the 40-times larger village. PMID:17620634

Sogoba, Nafomon; Doumbia, Seydou; Vounatsou, Penelope; Baber, Ibrahima; Keita, Moussa; Maiga, Mamoudou; Traor, Skou F; Tour, Abdoulaye; Dolo, Guimogo; Smith, Thomas; Ribeiro, Jos M C

2007-07-01

24

Vector competence of selected North American Culex and Coquillettidia mosquitoes for West Nile virus.  

PubMed Central

To control West Nile virus (WNV), it is necessary to know which mosquitoes are able to transmit this virus. Therefore, we evaluated the WNV vector potential of several North American mosquito species. Culex restuans and Cx. salinarius, two species from which WNV was isolated in New York in 2000, were efficient laboratory vectors. Cx. quinquefasciatus and Cx. nigripalpus from Florida were competent but only moderately efficient vectors. Coquillettidia perturbans was an inefficient laboratory vector. As WNV extends its range, exposure of additional mosquito species may alter its epidemiology. PMID:11747732

Sardelis, M. R.; Turell, M. J.; Dohm, D. J.; O'Guinn, M. L.

2001-01-01

25

Mosquito Vector Biting and Community Protection in a Malarious Area, Siahoo District, Hormozgan, Iran  

PubMed Central

Background: Use of bed-net continues to offer potential strategy for malaria prevention in endemic areas. Local communities are indispensable during design and implementation stages. Methods: A cross-sectional study of 192 randomly selected inhabitants was carried out in malarious zone, Siahoo direstrict, Hormozgan Province, southern Iran. In addition, we monitored human landing periodicity of main malaria vectors and as well as self-protection of inhabitant in the study area for a period of one transmission season between April to October 2006. Results The biting activities were seen throughout the whole night for three malaria vectors, Anopheles fluviatilis, An. stephensi and An. dthali, and An. fluviatilis exhibiting bimodal peaks, the first at midnight (0:00?1:00) and the other before dawn (5:00?6:00 am) but the maximum biting activity of An. stephensi was occurred at second quarter of night (11:00?12:00 pm). The majority of interviewers (83.3%) knew that malaria was transmitted by mosquitoes and 70.3% of them stated that bed-net is the best control measures. Most subjects (62%) did not have a mosquito net. Conclusion: Study subjects were aware of an association between mosquito bite and malaria transmission. Health workers at different levels of the health care delivery system should disseminate relevant information about self-protection to help community members to be involved more in malaria control. PMID:22808398

Shahandeh, KH; Basseri, HR; Pakari, A; Riazi, A

2010-01-01

26

Vector competence of Aedes aegypti mosquitoes for filarial nematodes is affected by age and nutrient limitation.  

PubMed

Mosquitoes are one of the most important vectors of human disease. The ability of mosquitoes to transmit disease is dependent on the age structure of the population, as mosquitoes must survive long enough for the parasites to complete their development and infect another human. Age could have additional effects due to mortality rates and vector competence changing as mosquitoes senesce, but these are comparatively poorly understood. We have investigated these factors using the mosquito Aedes aegypti and the filarial nematode Brugia malayi. Rather than observing any effects of immune senescence, we found that older mosquitoes were more resistant, but this only occurred if they had previously been maintained on a nutrient-poor diet of fructose. Constant blood feeding reversed this decline in vector competence, meaning that the number of parasites remained relatively unchanged as mosquitoes aged. Old females that had been maintained on fructose also experienced a sharp spike in mortality after an infected blood meal ("refeeding syndrome") and few survived long enough for the parasite to develop. Again, this effect was prevented by frequent blood meals. Our results indicate that old mosquitoes may be inefficient vectors due to low vector competence and high mortality, but that frequent blood meals can prevent these effects of age. PMID:25446985

Ariani, Cristina V; Juneja, Punita; Smith, Sophia; Tinsley, Matthew C; Jiggins, Francis M

2015-01-01

27

Climate-based models for West Nile Culex mosquito vectors in the Northeastern US  

Microsoft Academic Search

Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod. The results show a strong

Hongfei Gong; Arthur T. Degaetano; Laura C. Harrington

2011-01-01

28

Vector Competence of Australian Mosquitoes for Yellow Fever Virus  

PubMed Central

The vector competence of Australian mosquitoes for yellow fever virus (YFV) was evaluated. Infection and transmission rates in Cairns and Townsville populations of Aedes aegypti and a Brisbane strain of Ae. notoscriptus were not significantly different from a well-characterized YFV-susceptible strain of Ae. aegypti. After exposure to 107.2 tissue culture infectious dose (TCID50)/mL of an African strain of YFV, > 70% of Ae. aegypti and Ae. notoscriptus became infected, and > 50% transmitted the virus. When exposed to 106.7 TCID50/mL of a South American strain of YFV, the highest infection (64%) and transmission (56%) rates were observed in Ae. notoscriptus. The infection and transmission rates in the Cairns Ae. aegypti were both 24%, and they were 36% and 28%, respectively, for the Townsville population. Because competent vectors are present, the limited number of travelers from endemic areas and strict vaccination requirements will influence whether YFV transmission occurs in Australia. PMID:21896802

van den Hurk, Andrew F.; McElroy, Kate; Pyke, Alyssa T.; McGee, Charles E.; Hall-Mendelin, Sonja; Day, Andrew; Ryan, Peter A.; Ritchie, Scott A.; Vanlandingham, Dana L.; Higgs, Stephen

2011-01-01

29

Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Endophagic Filariasis, Arbovirus and Malaria Vectors  

PubMed Central

Background Partial mosquito-proofing of houses with screens and ceilings has the potential to reduce indoor densities of malaria mosquitoes. We wish to measure whether it will also reduce indoor densities of vectors of neglected tropical diseases. Methodology The main house entry points preferred by anopheline and culicine vectors were determined through controlled experiments using specially designed experimental huts and village houses in Lupiro village, southern Tanzania. The benefit of screening different entry points (eaves, windows and doors) using PVC-coated fibre glass netting material in terms of reduced indoor densities of mosquitoes was evaluated compared to the control. Findings 23,027 mosquitoes were caught with CDC light traps; 77.9% (17,929) were Anopheles gambiae sensu lato, of which 66.2% were An. arabiensis and 33.8% An. gambiae sensu stricto. The remainder comprised 0.2% (50) An. funestus, 10.2% (2359) Culex spp. and 11.6% (2664) Mansonia spp. Screening eaves reduced densities of Anopheles gambiae s. l. (Relative ratio (RR) ?=?0.91; 95% CI?=?0.84, 0.98; P?=?0.01); Mansonia africana (RR?=?0.43; 95% CI?=?0.26, 0.76; P<0.001) and Mansonia uniformis (RR?=?0.37; 95% CI?=?0.25, 0.56; P<0.001) but not Culex quinquefasciatus, Cx. univittatus or Cx. theileri. Numbers of these species were reduced by screening windows and doors but this was not significant. Significance This study confirms that across Africa, screening eaves protects households against important mosquito vectors of filariasis, Rift Valley Fever and O'Nyong nyong as well as malaria. While full house screening is required to exclude Culex species mosquitoes, screening of eaves alone or fitting ceilings has considerable potential for integrated control of other vectors of filariasis, arbovirus and malaria. PMID:20689815

Ogoma, Sheila B.; Lweitoijera, Dickson W.; Ngonyani, Hassan; Furer, Benjamin; Russell, Tanya L.; Mukabana, Wolfgang R.; Killeen, Gerry F.; Moore, Sarah J.

2010-01-01

30

Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector  

PubMed Central

Mosquitoes are thought to function as mechanical vectors of Francisella tularensis subspecies holarctica (F. t. holarctica) causing tularemia in humans. We investigated the clinical relevance of transstadially maintained F. t. holarctica in mosquitoes. Aedes egypti larvae exposed to a fully virulent F. t. holarctica strain for 24?hours, were allowed to develop into adults when they were individually homogenized. Approximately 24% of the homogenates tested positive for F. t. DNA in PCR. Mice injected with the mosquito homogenates acquired tularemia within 5 days. This novel finding demonstrates the possibility of transmission of bacteria by adult mosquitoes having acquired the pathogen from their aquatic larval habitats. PMID:25609657

Bckman, Stina; Nslund, Jonas; Forsman, Mats; Thelaus, Johanna

2015-01-01

31

Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector  

NASA Astrophysics Data System (ADS)

Mosquitoes are thought to function as mechanical vectors of Francisella tularensis subspecies holarctica (F. t. holarctica) causing tularemia in humans. We investigated the clinical relevance of transstadially maintained F. t. holarctica in mosquitoes. Aedes egypti larvae exposed to a fully virulent F. t. holarctica strain for 24 hours, were allowed to develop into adults when they were individually homogenized. Approximately 24% of the homogenates tested positive for F. t. DNA in PCR. Mice injected with the mosquito homogenates acquired tularemia within 5 days. This novel finding demonstrates the possibility of transmission of bacteria by adult mosquitoes having acquired the pathogen from their aquatic larval habitats.

Bckman, Stina; Nslund, Jonas; Forsman, Mats; Thelaus, Johanna

2015-01-01

32

Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector.  

PubMed

Mosquitoes are thought to function as mechanical vectors of Francisella tularensis subspecies holarctica (F. t. holarctica) causing tularemia in humans. We investigated the clinical relevance of transstadially maintained F. t. holarctica in mosquitoes. Aedes egypti larvae exposed to a fully virulent F. t. holarctica strain for 24?hours, were allowed to develop into adults when they were individually homogenized. Approximately 24% of the homogenates tested positive for F. t. DNA in PCR. Mice injected with the mosquito homogenates acquired tularemia within 5 days. This novel finding demonstrates the possibility of transmission of bacteria by adult mosquitoes having acquired the pathogen from their aquatic larval habitats. PMID:25609657

Bckman, Stina; Nslund, Jonas; Forsman, Mats; Thelaus, Johanna

2015-01-01

33

Occurrence of Japanese Encephalitis Virus Mosquito Vectors in Relation to Urban Pig Holdings  

PubMed Central

Japanese encephalitis virus (JEV) is transmitted to humans from pigs or birds by mosquitoes. In this study, the association between urban pig keeping and mosquito vectors was analyzed. A total of 7, 419 mosquitoes were collected overnight in urban households with and without pigs in Can Tho City, Vietnam. The most prevalent vectors were Culex tritaeniorhynchus (36%), Cx. gelidus (24%), and Cx. quinquefasciatus (15%), which were present in all parts of the city. Pigs were associated with increased numbers of Cx. tritaeniorhynchus. Traps close to pigs had higher numbers of Cx. tritaeniorhynchus and Cx. gelidus than traps close to humans. Increased number of persons in the household was associated with increased numbers of Cx. quinquefasciatus. We demonstrate that JEV vector species are present at urban households with and without pigs, and show that keeping pigs in an urban area increase the number of mosquitoes competent as vectors for JEV. PMID:23033401

Lindahl, Johanna; Chirico, Jan; Boqvist, Sofia; Thu, Ho Thi Viet; Magnusson, Ulf

2012-01-01

34

Occurrence of Japanese encephalitis virus mosquito vectors in relation to urban pig holdings.  

PubMed

Japanese encephalitis virus (JEV) is transmitted to humans from pigs or birds by mosquitoes. In this study, the association between urban pig keeping and mosquito vectors was analyzed. A total of 7, 419 mosquitoes were collected overnight in urban households with and without pigs in Can Tho City, Vietnam. The most prevalent vectors were Culex tritaeniorhynchus (36%), Cx. gelidus (24%), and Cx. quinquefasciatus (15%), which were present in all parts of the city. Pigs were associated with increased numbers of Cx. tritaeniorhynchus. Traps close to pigs had higher numbers of Cx. tritaeniorhynchus and Cx. gelidus than traps close to humans. Increased number of persons in the household was associated with increased numbers of Cx. quinquefasciatus. We demonstrate that JEV vector species are present at urban households with and without pigs, and show that keeping pigs in an urban area increase the number of mosquitoes competent as vectors for JEV. PMID:23033401

Lindahl, Johanna; Chirico, Jan; Boqvist, Sofia; Thu, Ho Thi Viet; Magnusson, Ulf

2012-12-01

35

Landscape Ecology of Sylvatic Chikungunya Virus and Mosquito Vectors in Southeastern Senegal  

PubMed Central

The risk of human infection with sylvatic chikungunya (CHIKV) virus was assessed in a focus of sylvatic arbovirus circulation in Senegal by investigating distribution and abundance of anthropophilic Aedes mosquitoes, as well as the abundance and distribution of CHIKV in these mosquitoes. A 1650 km2 area was classified into five land cover classes: forest, barren, savanna, agriculture and village. A total of 39,799 mosquitoes was sampled from all classes using human landing collections between June 2009 and January 2010. Mosquito diversity was extremely high, and overall vector abundance peaked at the start of the rainy season. CHIKV was detected in 42 mosquito pools. Our data suggest that Aedes furcifer, which occurred abundantly in all land cover classes and landed frequently on humans in villages outside of houses, is probably the major bridge vector responsible for the spillover of sylvatic CHIKV to humans. PMID:22720097

Diallo, Diawo; Sall, Amadou A.; Buenemann, Michaela; Chen, Rubing; Faye, Oumar; Diagne, Cheikh T.; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Watts, Douglas; Weaver, Scott C.; Hanley, Kathryn A.; Diallo, Mawlouth

2012-01-01

36

Mosquito genomics. Extensive introgression in a malaria vector species complex revealed by phylogenomics.  

PubMed

Introgressive hybridization is now recognized as a widespread phenomenon, but its role in evolution remains contested. Here, we use newly available reference genome assemblies to investigate phylogenetic relationships and introgression in a medically important group of Afrotropical mosquito sibling species. We have identified the correct species branching order to resolve a contentious phylogeny and show that lineages leading to the principal vectors of human malaria were among the first to split. Pervasive autosomal introgression between these malaria vectors means that only a small fraction of the genome, mainly on the X chromosome, has not crossed species boundaries. Our results suggest that traits enhancing vectorial capacity may be gained through interspecific gene flow, including between nonsister species. PMID:25431491

Fontaine, Michael C; Pease, James B; Steele, Aaron; Waterhouse, Robert M; Neafsey, Daniel E; Sharakhov, Igor V; Jiang, Xiaofang; Hall, Andrew B; Catteruccia, Flaminia; Kakani, Evdoxia; Mitchell, Sara N; Wu, Yi-Chieh; Smith, Hilary A; Love, R Rebecca; Lawniczak, Mara K; Slotman, Michel A; Emrich, Scott J; Hahn, Matthew W; Besansky, Nora J

2015-01-01

37

RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti  

Microsoft Academic Search

BACKGROUND: Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae), a vector of Dengue

Mariangela Bonizzoni; W Augustine Dunn; Corey L Campbell; Ken E Olson; Michelle T Dimon; Osvaldo Marinotti; Anthony A James

2011-01-01

38

Neural Responses to One-and Two-Tone Stimuli in the Hearing Organ of the Dengue Vector Mosquito  

E-print Network

Neural Responses to One- and Two-Tone Stimuli in the Hearing Organ of the Dengue Vector Mosquito Short title: Auditory Responses in Mosquitoes Keywords: sound recognition, efference copy, frequency studies demonstrate that mosquitoes listen to each other's wing beats just prior to mating in flight

Hoy, Ronald R.

39

Comparative Genomic Analysis of Drosophila melanogaster and Vector Mosquito Developmental Genes  

Microsoft Academic Search

Genome sequencing projects have presented the opportunity for analysis of developmental genes in three vector mosquito species: Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A comparative genomic analysis of developmental genes in Drosophila melanogaster and these three important vectors of human disease was performed in this investigation. While the study was comprehensive, special emphasis centered on genes that 1) are

Susanta K. Behura; Morgan Haugen; Ellen Flannery; Joseph Sarro; Charles R. Tessier; David W. Severson; Molly Duman-Scheel

2011-01-01

40

Repellent, irritant and toxic effects of 20 plant extracts on adults of the malaria vector Anopheles gambiae mosquito.  

PubMed

Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged. PMID:24376515

Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

2013-01-01

41

Repellent, Irritant and Toxic Effects of 20 Plant Extracts on Adults of the Malaria Vector Anopheles gambiae Mosquito  

PubMed Central

Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged. PMID:24376515

Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

2013-01-01

42

Efficacy of mosquito traps for collecting potential West Nile mosquito vectors in a natural Mediterranean wetland.  

PubMed

Surveillance, research, and control of mosquito-borne diseases such as West Nile virus require efficient methods for sampling mosquitoes. We compared the efficacy of BG-Sentinel and Centers for Disease Control and Prevention (CDC)-CO(2) traps in terms of the abundances of host-seeking and blood-fed female mosquitoes and the origin of mosquito bloodmeals. Our results indicate that BG-Sentinel traps that use CO(2) and attractants are as effective as CDC-CO(2) traps for Culex mosquito species, Ochlerotatus caspius, and they are also highly efficient at capturing Anopheles atroparvus host-seeking and blood-fed females with or without CO(2). The CDC-CO(2) trap is the least efficient method for capturing blood-fed females. BG-Sentinel traps with attractants and CO(2) were significantly better at capturing mosquitoes that had fed on mammals than the unbaited BG-Sentinel and CDC-CO(2) traps in the cases of An. atroparvus and Cx. theileri. These results may help researchers to optimize trapping methods by obtaining greater sample sizes and saving time and money. PMID:22492149

Roiz, David; Roussel, Marion; Muoz, Joaquin; Ruiz, Santiago; Soriguer, Ramn; Figuerola, Jordi

2012-04-01

43

Climate-based models for West Nile Culex mosquito vectors in the Northeastern US  

Microsoft Academic Search

Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito\\u000a population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod.\\u000a The results show a strong

Hongfei Gong; Arthur T. DeGaetano; Laura C. Harrington

2011-01-01

44

Mosquito PlasmodiumInteractions in Response to Immune Activation of the Vector  

Microsoft Academic Search

Lowenberger, C. A., Kamal, S., Chiles, J., Paskewitz, S., Bulet, P., Hoffmann, J. A., and Christensen, B. M. 1999. Mosquito-Plasmodiuminteractions in response to immune activation of the vector.Experimental Parasitology91,5969. During the development ofPlasmodiumsp. within the mosquito midgut, the parasite undergoes a series of developmental changes. The elongated ookinete migrates through the layers of the midgut where it forms the oocyst

Carl A. Lowenberger; Sofie Kamal; Jody Chiles; Susan Paskewitz; Philippe Bulet; Jules A. Hoffmann; Bruce M. Christensen

1999-01-01

45

Spatial autocorrelation of West Nile virus vector mosquito abundance in a seasonally wet suburban environment  

Microsoft Academic Search

The objective of this study is to quantify and model spatial dependence in mosquito vector populations and develop predictions\\u000a for unsampled locations using geostatistics. Mosquito control program trap sites are often located too far apart to detect\\u000a spatial dependence but the results show that integration of spatial data over time for Cx. pipiens-restuans and according to meteorological conditions for Ae.

P. R. Trawinski; D. S. Mackay

2009-01-01

46

Construction and characterization of an expressed sequenced tag library for the mosquito vector Armigeres subalbatus  

PubMed Central

Background The mosquito, Armigeres subalbatus, mounts a distinctively robust innate immune response when infected with the nematode Brugia malayi, a causative agent of lymphatic filariasis. In order to mine the transcriptome for new insight into the cascade of events that takes place in response to infection in this mosquito, 6 cDNA libraries were generated from tissues of adult female mosquitoes subjected to immune-response activation treatments that lead to well-characterized responses, and from aging, nave mosquitoes. Expressed sequence tags (ESTs) from each library were produced, annotated, and subjected to comparative analyses. Results Six libraries were constructed and used to generate 44,940 expressed sequence tags, of which 38,079 passed quality filters to be included in the annotation project and subsequent analyses. All of these sequences were collapsed into clusters resulting in 8,020 unique sequence clusters or singletons. EST clusters were annotated and curated manually within ASAP (A Systematic Annotation Package for Community Analysis of Genomes) web portal according to BLAST results from comparisons to Genbank, and the Anopheles gambiae and Drosophila melanogaster genome projects. Conclusion The resulting dataset is the first of its kind for this mosquito vector and provides a basis for future studies of mosquito vectors regarding the cascade of events that occurs in response to infection, and thereby providing insight into vector competence and innate immunity. PMID:18088419

Mayhew, George F; Bartholomay, Lyric C; Kou, Hang-Yen; Rocheleau, Thomas A; Fuchs, Jeremy F; Aliota, Matthew T; Tsao, I-Yu; Huang, Chiung-Yen; Liu, Tze-Tze; Hsiao, Kwang-Jen; Tsai, Shih-Feng; Yang, Ueng-Cheng; Perna, Nicole T; Cho, Wen-Long; Christensen, Bruce M; Chen, Cheng-Chen

2007-01-01

47

Mode of transmission and the evolution of arbovirus virulence in mosquito vectors  

PubMed Central

The traditional assumption that vector-borne pathogens should evolve towards a benign relationship with their arthropod vectors has been challenged on theoretical grounds and empirical evidence. However, in the case of arboviruses (arthropod-borne viruses), although a number of investigators have reported experimental evidence for virus-induced vector mortality, others have failed to detect any significant impact. Whether this variation in the observed level of arbovirus virulence depends on biological traits or experimental design is unclear. Here, we perform a meta-analysis of studies across a range of mosquitovirus systems to show that, overall, arboviruses do reduce the survival of their mosquito vectors, but that the magnitude of the effect depends on the vector/virus taxonomic groups and the mode of virus transmission. Alphaviruses were associated with highest virulence levels in mosquitoes. Horizontal transmission (intrathoracic inoculation or oral infection) was correlated with significant virus-induced mortality, whereas a lack of adverse effect was found for Aedes mosquitoes infected transovarially by bunyavirusesa group of viruses characterized by high natural rates of vertical transmission in their enzootic vectors. Our findings are consistent with the general prediction that vertically transmitted pathogens should be less virulent than those transmitted horizontally. We conclude that varying degrees of virulence observed among vectorvirus systems probably reflect different selective pressures imposed on arboviruses that are primarily transmitted horizontally versus vertically. PMID:19141420

Lambrechts, Louis; Scott, Thomas W.

2009-01-01

48

Potential impacts of climate change on the ecology of dengue and its mosquito vector the Asian tiger mosquito (Aedes albopictus)  

NASA Astrophysics Data System (ADS)

Shifts in temperature and precipitation patterns caused by global climate change may have profound impacts on the ecology of certain infectious diseases. We examine the potential impacts of climate change on the transmission and maintenance dynamics of dengue, a resurging mosquito-vectored infectious disease. In particular, we project changes in dengue season length for three cities: Atlanta, GA; Chicago, IL and Lubbock, TX. These cities are located on the edges of the range of the Asian tiger mosquito within the United States of America and were chosen as test cases. We use a disease model that explicitly incorporates mosquito population dynamics and high-resolution climate projections. Based on projected changes under the Special Report on Emissions Scenarios (SRES) A1fi (higher) and B1 (lower) emission scenarios as simulated by four global climate models, we found that the projected warming shortened mosquito lifespan, which in turn decreased the potential dengue season. These results illustrate the difficulty in predicting how climate change may alter complex systems.

Erickson, R. A.; Hayhoe, K.; Presley, S. M.; Allen, L. J. S.; Long, K. R.; Cox, S. B.

2012-09-01

49

Potential transmission of West Nile virus in the British Isles: an ecological review of candidate mosquito bridge vectors.  

PubMed

West Nile virus (WNV) transmitted by mosquitoes (Diptera: Culicidae) infects various vertebrates, being pathogenic for birds, horses and humans. After its discovery in tropical Africa, sporadic outbreaks of WNV occurred during recent decades in Eurasia, but not the British Isles. WNV reached New York in 1999 and spread to California by 2003, causing widespread outbreaks of West Nile encephalitis across North America, transmitted by many species of mosquitoes, mainly Culex spp. The periodic reappearance of WNV in parts of continental Europe (from southern France to Romania) gives rise to concern over the possibility of WNV invading the British Isles. The British Isles have about 30 endemic mosquito species, several with seasonal abundance and other eco-behavioural characteristics predisposing them to serve as potential WNV bridge vectors from birds to humans. These include: the predominantly ornithophilic Culex pipiens L. and its anthropophilic biotype molestus Forskal; tree-hole adapted Anopheles plumbeus Stephens; saltmarsh-adapted Ochlerotatus caspius Pallas, Oc. detritus Haliday and Oc. dorsalis (Meigen); Coquillettidia richiardii Ficalbi, Culiseta annulata Schrank and Cs. morsitans (Theobald) from vegetated freshwater pools; Aedes cinereus Meigen, Oc. cantans Meigen and Oc. punctor Kirby from seasonal woodland pools. Those underlined have been found carrying WNV in other countries (12 species), including the rarer British species Aedes vexans (Meigen), Culex europaeus Ramos et al., Cx. modestus Ficalbi and Oc. sticticus (Meigen) as well as the Anopheles maculipennis Meigen complex (mainly An. atroparvus van Thiel and An. messeae Falleroni in Britain). Those implicated as key vectors of WNV in Europe are printed bold (four species). So far there is no proof of any arbovirus transmission by mosquitoes in the British Isles, although antibodies to Sindbis, Tahyna, Usutu and West Nile viruses have been detected in British birds. Neighbouring European countries have enzootic WNV and human infections transmitted by mosquito species that are present in the British Isles. However, except for localized urban infestations of Cx. pipiens biotype molestus that can be readily eliminated, there appear to be few situations in the British Isles where humans and livestock are exposed to sustained risks of exposure to potential WNV vectors. Monitoring of mosquitoes and arbovirus surveillance are required to guard the British Isles against WNV outbreaks and introduction of more anthropophilic mosquitoes such as Stegomyia albopicta (Skuse) and Ochlerotatus japonicus (Theobald) that have recently invaded Europe, since they transmit arboviruses elsewhere. PMID:15752172

Medlock, J M; Snow, K R; Leach, S

2005-03-01

50

Identification of microRNAs expressed in two mosquito vectors, Aedes albopictus and Culex quinquefasciatus  

PubMed Central

Background MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression in a variety of organisms, including insects, vertebrates, and plants. miRNAs play important roles in cell development and differentiation as well as in the cellular response to stress and infection. To date, there are limited reports of miRNA identification in mosquitoes, insects that act as essential vectors for the transmission of many human pathogens, including flaviviruses. West Nile virus (WNV) and dengue virus, members of the Flaviviridae family, are primarily transmitted by Aedes and Culex mosquitoes. Using high-throughput deep sequencing, we examined the miRNA repertoire in Ae. albopictus cells and Cx. quinquefasciatus mosquitoes. Results We identified a total of 65 miRNAs in the Ae. albopictus C7/10 cell line and 77 miRNAs in Cx. quinquefasciatus mosquitoes, the majority of which are conserved in other insects such as Drosophila melanogaster and Anopheles gambiae. The most highly expressed miRNA in both mosquito species was miR-184, a miRNA conserved from insects to vertebrates. Several previously reported Anopheles miRNAs, including miR-1890 and miR-1891, were also found in Culex and Aedes, and appear to be restricted to mosquitoes. We identified seven novel miRNAs, arising from nine different precursors, in C7/10 cells and Cx. quinquefasciatus mosquitoes, two of which have predicted orthologs in An. gambiae. Several of these novel miRNAs reside within a ~350 nt long cluster present in both Aedes and Culex. miRNA expression was confirmed by primer extension analysis. To determine whether flavivirus infection affects miRNA expression, we infected female Culex mosquitoes with WNV. Two miRNAs, miR-92 and miR-989, showed significant changes in expression levels following WNV infection. Conclusions Aedes and Culex mosquitoes are important flavivirus vectors. Recent advances in both mosquito genomics and high-throughput sequencing technologies enabled us to interrogate the miRNA profile in these two species. Here, we provide evidence for over 60 conserved and seven novel mosquito miRNAs, expanding upon our current understanding of insect miRNAs. Undoubtedly, some of the miRNAs identified will have roles not only in mosquito development, but also in mediating viral infection in the mosquito host. PMID:20167119

2010-01-01

51

Cooler Temperatures Destabilize RNA Interference and Increase Susceptibility of Disease Vector Mosquitoes to Viral Infection  

PubMed Central

Background The impact of global climate change on the transmission dynamics of infectious diseases is the subject of extensive debate. The transmission of mosquito-borne viral diseases is particularly complex, with climatic variables directly affecting many parameters associated with the prevalence of disease vectors. While evidence shows that warmer temperatures often decrease the extrinsic incubation period of an arthropod-borne virus (arbovirus), exposure to cooler temperatures often predisposes disease vector mosquitoes to higher infection rates. RNA interference (RNAi) pathways are essential to antiviral immunity in the mosquito; however, few experiments have explored the effects of temperature on the RNAi machinery. Methodology/Principal Findings We utilized transgenic sensor strains of Aedes aegypti to examine the role of temperature on RNA silencing. These sensor strains express EGFP only when RNAi is inhibited; for example, after knockdown of the effector proteins Dicer-2 (DCR-2) or Argonaute-2 (AGO-2). We observed an increase in EGFP expression in transgenic sensor mosquitoes reared at 18C as compared with 28C. Changes in expression were dependent on the presence of an inverted repeat with homology to a portion of the EGFP sequence, as transgenic strains lacking this sequence, the double stranded RNA (dsRNA) trigger for RNAi, showed no change in EGFP expression when reared at 18C. Sequencing small RNAs in sensor mosquitoes reared at low temperature revealed normal processing of dsRNA substrates, suggesting the observed deficiency in RNAi occurs downstream of DCR-2. Rearing at cooler temperatures also predisposed mosquitoes to higher levels of infection with both chikungunya and yellow fever viruses. Conclusions/Significance This data suggest that microclimates, such as those present in mosquito breeding sites, as well as more general climactic variables may influence the dynamics of mosquito-borne viral diseases by affecting the antiviral immunity of disease vectors. PMID:23738025

Adelman, Zach N.; Anderson, Michelle A. E.; Wiley, Michael R.; Murreddu, Marta G.; Samuel, Glady Hazitha; Morazzani, Elaine M.; Myles, Kevin M.

2013-01-01

52

Identification of the main malaria vectors in the Anopheles gambiae species complex using a TaqMan real-time PCR assay  

Microsoft Academic Search

BACKGROUND: The Anopheles gambiae sensu lato species complex comprises seven sibling species of mosquitoes that are morphologically indistinguishable. Rapid identification of the two main species which vector malaria, Anopheles arabiensis and An. gambiae sensu stricto, from the non-vector species Anopheles quadriannulatus is often required as part of vector control programmes. Currently the most widely used method for species identification is

Chris Bass; Martin S Williamson; Craig S Wilding; Martin J Donnelly; Linda M Field

2007-01-01

53

High-throughput sorting of mosquito larvae for laboratory studies and for future vector control interventions  

PubMed Central

Background Mosquito transgenesis offers new promises for the genetic control of vector-borne infectious diseases such as malaria and dengue fever. Genetic control strategies require the release of large number of male mosquitoes into field populations, whether they are based on the use of sterile males (sterile insect technique, SIT) or on introducing genetic traits conferring refractoriness to disease transmission (population replacement). However, the current absence of high-throughput techniques for sorting different mosquito populations impairs the application of these control measures. Methods A method was developed to generate large mosquito populations of the desired sex and genotype. This method combines flow cytometry and the use of Anopheles gambiae transgenic lines that differentially express fluorescent markers in males and females. Results Fluorescence-assisted sorting allowed single-step isolation of homozygous transgenic mosquitoes from a mixed population. This method was also used to select wild-type males only with high efficiency and accuracy, a highly desirable tool for genetic control strategies where the release of transgenic individuals may be problematic. Importantly, sorted males showed normal mating ability compared to their unsorted brothers. Conclusions The developed method will greatly facilitate both laboratory studies of mosquito vectorial capacity requiring high-throughput approaches and future field interventions in the fight against infectious disease vectors. PMID:22929810

2012-01-01

54

Interspecific transfer of Wolbachia into the mosquito disease vector Aedes albopictus  

PubMed Central

Intracellular Wolbachia bacteria are obligate, maternally inherited endosymbionts found frequently in insects and other invertebrates. The evolutionary success of Wolbachia is due in part to an ability to manipulate reproduction. In mosquitoes and many other insects, Wolbachia causes a form of sterility known as cytoplasmic incompatibility (CI). Wolbachia-induced CI has attracted interest as a potential agent for affecting medically important disease vectors. However, application of the approach has been restricted by an absence of appropriate, naturally occurring Wolbachia infections. Here, we report the interspecific transfer of Wolbachia infection into a medically important mosquito. Using embryonic microinjection, Wolbachia is transferred from Drosophila simulans into the invasive pest and disease vector: Aedes albopictus (Asian tiger mosquito). The resulting infection is stably maintained and displays a unique pattern of bidirectional CI in crosses with naturally infected mosquitoes. Laboratory population cage experiments examine a strategy in which releases of Wolbachia-infected males are used to suppress mosquito egg hatch. We discuss the results in relation to developing appropriate Wolbachia-infected mosquito strains for population replacement and population suppression strategies. PMID:16777718

Xi, Zhiyong; Khoo, Cynthia C.H; Dobson, Stephen L

2006-01-01

55

Evidence for regular ongoing introductions of mosquito disease vectors into the Galpagos Islands  

PubMed Central

Wildlife on isolated oceanic islands is highly susceptible to the introduction of pathogens. The recent establishment in the Galpagos Islands of the mosquito Culex quinquefasciatus, a vector for diseases such as avian malaria and West Nile fever, is considered a serious risk factor for the archipelago's endemic fauna. Here we present evidence from the monitoring of aeroplanes and genetic analysis that C. quinquefasciatus is regularly introduced via aircraft into the Galpagos Archipelago. Genetic population structure and admixture analysis demonstrates that these mosquitoes breed with, and integrate successfully into, already-established populations of C. quinquefasciatus in the Galpagos, and that there is ongoing movement of mosquitoes between islands. Tourist cruise boats and inter-island boat services are the most likely mechanism for transporting Culex mosquitoes between islands. Such anthropogenic mosquito movements increase the risk of the introduction of mosquito-borne diseases novel to Galpagos and their subsequent widespread dissemination across the archipelago. Failure to implement and maintain measures to prevent the human-assisted transport of mosquitoes to and among the islands could have catastrophic consequences for the endemic wildlife of Galpagos. PMID:19675009

Bataille, Arnaud; Cunningham, Andrew A.; Cedeo, Virna; Cruz, Marilyn; Eastwood, Gillian; Fonseca, Dina M.; Causton, Charlotte E.; Azuero, Ronal; Loayza, Jose; Martinez, Jose D. Cruz; Goodman, Simon J.

2009-01-01

56

Harmonic convergence in the love songs of the dengue vector mosquito  

PubMed Central

The familiar buzz of flying mosquitoes is an important mating signal, with the fundamental frequency of the female's flight tone signalling her presence. In the yellow fever and dengue vector, Aedes aegypti, both sexes interact acoustically by shifting their flight tones to match, resulting in a courtship duet. Surprisingly, matching is made not at the fundamental frequency of 400 Hz (female) or 600 Hz (male), but at a shared harmonic of 1200 Hz, which exceeds the previously known upper limit of hearing in mosquitoes. Physiological recordings from Johnston's organ (the mosquito's ear) reveal sensitivity up to 2000 Hz, consistent with our observed courtship behavior. These findings revise widely accepted limits of acoustic behavior in mosquitoes. PMID:19131593

Cator, Lauren J.; Arthur, Ben J.; Harrington, Laura C.; Hoy, Ronald R.

2010-01-01

57

VectorHost Interactions in Avian Nests: Do Mosquitoes Prefer Nestlings over Adults?  

PubMed Central

The hypothesis that nestlings are a significant driver of arbovirus transmission and amplification is based upon findings that suggest nestlings are highly susceptible to being fed upon by vector mosquitoes and to viral infection and replication. Several previous studies have suggested that nestlings are preferentially fed upon relative to adults in the nest, and other studies have reported a preference for adults over nestlings. We directly tested the feeding preference of nestling and adult birds in a natural setting, introducing mosquitoes into nesting boxes containing eastern bluebirds (Sialia sialis), collecting blood-fed mosquitoes, and matching the source of mosquito blood meals to individual birds using microsatellite markers. Neither nestlings nor adults were fed upon to an extent significantly greater than would be predicted based upon their relative abundance in the nests, although feeding upon mothers decreased as the age of the nestlings increased. PMID:20682889

Burkett-Cadena, Nathan D.; Ligon, Russell A.; Liu, Mark; Hassan, Hassan K.; Hill, Geoffrey E.; Eubanks, Micky D.; Unnasch, Thomas R.

2010-01-01

58

Vector-host interactions in avian nests: do mosquitoes prefer nestlings over adults?  

PubMed

The hypothesis that nestlings are a significant driver of arbovirus transmission and amplification is based upon findings that suggest nestlings are highly susceptible to being fed upon by vector mosquitoes and to viral infection and replication. Several previous studies have suggested that nestlings are preferentially fed upon relative to adults in the nest, and other studies have reported a preference for adults over nestlings. We directly tested the feeding preference of nestling and adult birds in a natural setting, introducing mosquitoes into nesting boxes containing eastern bluebirds (Sialia sialis), collecting blood-fed mosquitoes, and matching the source of mosquito blood meals to individual birds using microsatellite markers. Neither nestlings nor adults were fed upon to an extent significantly greater than would be predicted based upon their relative abundance in the nests, although feeding upon mothers decreased as the age of the nestlings increased. PMID:20682889

Burkett-Cadena, Nathan D; Ligon, Russell A; Liu, Mark; Hassan, Hassan K; Hill, Geoffrey E; Eubanks, Micky D; Unnasch, Thomas R

2010-08-01

59

The Effective Population Size of Malaria Mosquitoes: Large Impact of Vector Control  

PubMed Central

Malaria vectors in sub-Saharan Africa have proven themselves very difficult adversaries in the global struggle against malaria. Decades of anti-vector interventions have yielded mixed resultswith successful reductions in transmission in some areas and limited impacts in others. These varying successes can be ascribed to a lack of universally effective vector control tools, as well as the development of insecticide resistance in mosquito populations. Understanding the impact of vector control on mosquito populations is crucial for planning new interventions and evaluating existing ones. However, estimates of population size changes in response to control efforts are often inaccurate because of limitations and biases in collection methods. Attempts to evaluate the impact of vector control on mosquito effective population size (Ne) have produced inconclusive results thus far. Therefore, we obtained data for 1315 microsatellite markers for more than 1,500 mosquitoes representing multiple time points for seven populations of three important vector speciesAnopheles gambiae, An. melas, and An. mouchetiin Equatorial Guinea. These populations were exposed to indoor residual spraying or long-lasting insecticidal nets in recent years. For comparison, we also analyzed data from two populations that have no history of organized vector control. We used Approximate Bayesian Computation to reconstruct their demographic history, allowing us to evaluate the impact of these interventions on the effective population size. In six of the seven study populations, vector control had a dramatic impact on the effective population size, reducing Ne between 55%87%, the exception being a single An. melas population. In contrast, the two negative control populations did not experience a reduction in effective population size. This study is the first to conclusively link anti-vector intervention programs in Africa to sharply reduced effective population sizes of malaria vectors. PMID:23271973

Athrey, Giridhar; Hodges, Theresa K.; Reddy, Michael R.; Overgaard, Hans J.; Matias, Abrahan; Ridl, Frances C.; Kleinschmidt, Immo; Caccone, Adalgisa; Slotman, Michel A.

2012-01-01

60

Identification of environmental covariates of West Nile virus vector mosquito population abundance.  

PubMed

The rapid spread of West Nile virus (WNv) in North America is a major public health concern. Culex pipiens-restuans is the principle mosquito vector of WNv in the northeastern United States while Aedes vexans is an important bridge vector of the virus in this region. Vector mosquito abundance is directly dependent on physical environmental factors that provide mosquito habitats. The objective of this research is to determine landscape elements that explain the population abundance and distribution of WNv vector mosquitoes using stepwise linear regression. We developed a novel approach for examining a large set of landscape variables based on a land use and land cover classification by selecting variables in stages to minimize multicollinearity. We also investigated the distance at which landscape elements influence abundance of vector populations using buffer distances of 200, 400, and 1000 m. Results show landscape effects have a significant impact on Cx. pipiens-estuans population distribution while the effects of landscape features are less important for prediction of Ae. vexans population distributions. Cx. pipiens-restuans population abundance is positively correlated with human population density, housing unit density, and urban land use and land cover classes and negatively correlated with age of dwellings and amount of forested land. PMID:20482343

Trawinski, Patricia R; Mackay, D Scott

2010-06-01

61

Mosquitoes  

NSDL National Science Digital Library

This tutorial is part of a series of entomological tutorials and covers the general biology and ecology of mosquitoes. The tutorial has 100 questions (50 in each of 2 tutorials); incorrect answers lead to additional information describing the correct answers. Covers all mosquito genera and their habitats, identification, life cycle, biology, and economic importance. Requires Windows. MAC is not supported. The cost for the tutorial CD is $15.

0000-00-00

62

Yellow fever virus susceptibility of two mosquito vectors from Kenya, East Africa.  

PubMed

Yellow fever is an unpredictable disease of increasing epidemic threat in East Africa. Aedes (Stegomyia) aegypti has never been implicated as a vector in this region and recent outbreaks have involved a newly emerging virus genotype (East African). To better understand the increasing epidemic risk of yellow fever in East Africa, this study is the first to investigate the vector competence for an emerging East African virus genotype in Kenyan A. aegypti sensu latu (s.l) and A. (Stegomyia) simpsoni s.l. mosquito species. Using first filial generation mosquitoes and a low passage yellow fever virus, this study demonstrated that although A. aegypti s.l. is a competent vector, A. simpsoni s.l. is likely a more efficient vector. PMID:22521217

Ellis, Brett R; Sang, Rosemary C; Horne, Kate McElroy; Higgs, Stephen; Wesson, Dawn M

2012-06-01

63

MOSQUITO VECTOR CONTROL AND BIOLOGY IN LATIN AMERICA - A 16TH SYMPOSIUM  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 16th Annual Latin American Symposium presented by the American Mosquito Control Association (AMCA) was held as part of the 72nd Annual Meeting in Detroit, Michigan in February 2006. The principal objective, as for the previous 15 symposia, was to promote participation in the AMCA by vector cont...

64

VECTOR-BORNE DISEASES, SURVEILLANCE, PREVENTION Host Antibodies in Mosquito Bloodmeals: A Potential Tool to Detect  

E-print Network

VECTOR-BORNE DISEASES, SURVEILLANCE, PREVENTION Host Antibodies in Mosquito Bloodmeals: A Potential to zoonotic diseases such as hantavirus, Lyme disease, avian in?uenza, and rabies. Many livestock diseases may is essential to reduce transmission to humans and livestock and within wildlife populations. Surveillance

Lowenberger, Carl

65

Efficacy of extracts of Bacillus thuringiensis israelensis for the control of mosquito vectors.  

Technology Transfer Automated Retrieval System (TEKTRAN)

More than 1 million human cases of Chikungunya were recently reported in India. Aedes aegypti (the yellow fever mosquito) is an important disease vector in India where it transmits Chikungunya, dengue, and yellow fever viruses to humans. In this study, scientists from Bharathiar University in Coim...

66

An Integrated Genetic Map of the African Human Malaria Vector Mosquito, Anopheles gambiae  

Microsoft Academic Search

We present a genetic map based on microsatellite polymorphisms for the African human malaria vector, Anopheles gambiae. Polymorphisms in laboratory strains were detected for 89% of the tested microsatellite markers. Genotyping was performed for individual mosquitoes from 13 backcross families that included 679 progeny. Three linkage groups were identified, corresponding to the three chromo- somes. We added 22 new markers

Liangbiao Zheng; Mark Q. Benedict; Anton J. Cornel; Frank H. Collins; Fotis C. Kafatos

67

Using global information technology to detect, monitor, and control mosquito pest and disease vector populations.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Geographic Information Systems (GIS), image analysis, and remote sensing comprise global information technologies that are used to characterize pest and vector populations of mosquitoes. At this national meeting, scientists from ARS and McNeese State University organized and convened a half-day sym...

68

Mosquito vector biology and control in Latin America - a 24th symposium  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 24th Annual Latin American Symposium presented by the American Mosquito Control Association (AMCA) was held as part of the 80th Annual Meeting in Seattle, WA in February 2014. The principal objective, as for the previous 23 symposia, was to promote participation in the AMCA by vector control spe...

69

[The molecular diagnosis of Dirofilaria immitis in vector mosquitoes in Felahiye district of Kayseri].  

PubMed

This study was designed to determine the potential vectors of Dirofilaria immitis by molecular techniques in Felahiye district of Kayseri. Mosquitoes were sampled from 11 points between June-August 2008 and collected live samples were brought to laboratory. In order to allow the larval development, mosquitoes were incubated in in vitro conditions for seven days. After this mosquitoes were killed and species identifications were done. Among the totally collected 301 mosquitoes, 96 (31.9%) were belonging to Aedes vexans and 205 (68.1%) to Culex pipiens. Head-thorax and abdomens of each sample were dissected to determine the infective and infected mosquitoes and totally 54 pools (2-17 sample/pool) were constituted according to species and collected region. Genomic DNA was extracted from pools and analyzed by PCR using species specific primers. Dirofilaria immitis DNA was found in 2/54 of the pools formed with one head-thorax and one abdomen pool of Ae. vexans. The minimum infection rate (MIRs) was calculated as 0.33 % in the study area. MIRs of 20 pools consisted from Ae. vexans was determined as 1.04 %. No filarial DNA was detected in 34 pools consisted from Cx. pipiens. Consequently, Ae. vexans was the active potential vector of D. immitis in the study area. PMID:20954124

B??k?n, Zuhal; Dzl, Onder; Yildirim, Alparslan; Inc?, Abdullah

2010-01-01

70

Outdoor host seeking behaviour of Anopheles gambiae mosquitoes following initiation of malaria vector control on Bioko Island, Equatorial Guinea  

Microsoft Academic Search

BackgroundIndoor-based anti-vector interventions remain the preferred means of reducing risk of malaria transmission in malaria endemic\\u000a areas around the world. Despite demonstrated success in reducing human-mosquito interactions, these methods are effective\\u000a solely against endophilic vectors. It may be that outdoor locations serve as an important venue of host seeking by Anopheles gambiae sensu lato (s.l.) mosquitoes where indoor vector suppression

Michael R Reddy; Hans J Overgaard; Simon Abaga; Vamsi P Reddy; Adalgisa Caccone; Anthony E Kiszewski; Michel A Slotman

2011-01-01

71

Relationship between Exposure to Vector Bites and Antibody Responses to Mosquito Salivary Gland Extracts  

PubMed Central

Mosquito-borne diseases are major health problems worldwide. Serological responses to mosquito saliva proteins may be useful in estimating individual exposure to bites from mosquitoes transmitting these diseases. However, the relationships between the levels of these IgG responses and mosquito density as well as IgG response specificity at the genus and/or species level need to be clarified prior to develop new immunological markers to assess human/vector contact. To this end, a kinetic study of antibody levels against several mosquito salivary gland extracts from southeastern French individuals living in three areas with distinct ecological environments and, by implication, distinct Aedes caspius mosquito densities were compared using ELISA. A positive association was observed between the average levels of IgG responses against Ae. caspius salivary gland extracts and spatial Ae. caspius densities. Additionally, the average level of IgG responses increased significantly during the peak exposure to Ae. caspius at each site and returned to baseline four months later, suggesting short-lived IgG responses. The species-specificity of IgG antibody responses was determined by testing antibody responses to salivary gland extracts from Cx. pipiens, a mosquito that is present at these three sites at different density levels, and from two other Aedes species not present in the study area (Ae. aegypti and Ae. albopictus). The IgG responses observed against these mosquito salivary gland extracts contrasted with those observed against Ae. caspius salivary gland extracts, supporting the existence of species-specific serological responses. By considering different populations and densities of mosquitoes linked to environmental factors, this study shows, for the first time, that specific IgG antibody responses against Ae. caspius salivary gland extracts may be related to the seasonal and geographical variations in Ae. caspius density. Characterisation of such immunological-markers may allow the evaluation of the effectiveness of vector-control strategies or estimation of the risk of vector-borne disease transmission. PMID:22195000

Orlandi-Pradines, Eve; Diouf, Ibrahima; Remou, Franck; Pags, Frdric; Fusa, Thierry; Rogier, Christophe; Almeras, Lionel

2011-01-01

72

Insect-specific viruses detected in laboratory mosquito colonies and their potential implications for experiments evaluating arbovirus vector competence.  

PubMed

Recently, there has been a dramatic increase in the detection and characterization of insect-specific viruses in field-collected mosquitoes. Evidence suggests that these viruses are ubiquitous in nature and that many are maintained by vertical transmission in mosquito populations. Some studies suggest that the presence of insect-specific viruses may inhibit replication of a super-infecting arbovirus, thus altering vector competence of the mosquito host. Accordingly, we screened our laboratory mosquito colonies for insect-specific viruses. Pools of colony mosquitoes were homogenized and inoculated into cultures of Aedes albopictus (C6/36) cells. The infected cells were examined by electron microscopy and deep sequencing was performed on RNA extracts. Electron micrograph images indicated the presence of three different viruses in three of our laboratory mosquito colonies. Potential implications of these findings for vector competence studies are discussed. PMID:25510714

Bolling, Bethany G; Vasilakis, Nikos; Guzman, Hilda; Widen, Steven G; Wood, Thomas G; Popov, Vsevolod L; Thangamani, Saravanan; Tesh, Robert B

2015-02-01

73

The Genome of Anopheles darlingi, the main neotropical malaria vector  

PubMed Central

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ?100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi. PMID:23761445

Marinotti, Osvaldo; Cerqueira, Gustavo C.; de Almeida, Luiz Gonzaga Paula; Ferro, Maria Ins Tiraboschi; Loreto, Elgion Lucio da Silva; Zaha, Arnaldo; Teixeira, Santuza M. R.; Wespiser, Adam R.; Almeida e Silva, Alexandre; Schlindwein, Aline Daiane; Pacheco, Ana Carolina Landim; da Silva, Artur Luiz da Costa; Graveley, Brenton R.; Walenz, Brian P.; Lima, Bruna de Araujo; Ribeiro, Carlos Alexandre Gomes; Nunes-Silva, Carlos Gustavo; de Carvalho, Carlos Roberto; Soares, Clia Maria de Almeida; de Menezes, Claudia Beatriz Afonso; Matiolli, Cleverson; Caffrey, Daniel; Arajo, Demetrius Antonio M.; de Oliveira, Diana Magalhes; Golenbock, Douglas; Grisard, Edmundo Carlos; Fantinatti-Garboggini, Fabiana; de Carvalho, Fabola Marques; Barcellos, Fernando Gomes; Prosdocimi, Francisco; May, Gemma; de Azevedo Junior, Gilson Martins; Guimares, Giselle Moura; Goldman, Gustavo Henrique; Padilha, Itcio Q. M.; Batista, Jacqueline da Silva; Ferro, Jesus Aparecido; Ribeiro, Jos M. C.; Fietto, Juliana Lopes Rangel; Dabbas, Karina Maia; Cerdeira, Louise; Agnez-Lima, Lucymara Fassarella; Brocchi, Marcelo; de Carvalho, Marcos Oliveira; Teixeira, Marcus de Melo; Diniz Maia, Maria de Mascena; Goldman, Maria Helena S.; Cruz Schneider, Maria Paula; Felipe, Maria Sueli Soares; Hungria, Mariangela; Nicols, Marisa Fabiana; Pereira, Maristela; Montes, Martn Alejandro; Canto, Maurcio E.; Vincentz, Michel; Rafael, Miriam Silva; Silverman, Neal; Stoco, Patrcia Hermes; Souza, Rangel Celso; Vicentini, Renato; Gazzinelli, Ricardo Tostes; Neves, Rogrio de Oliveira; Silva, Rosane; Astolfi-Filho, Spartaco; Maciel, Talles Eduardo Ferreira; rmnyi, Turn P.; Tadei, Wanderli Pedro; Camargo, Erney Plessmann; de Vasconcelos, Ana Tereza Ribeiro

2013-01-01

74

The genome of Anopheles darlingi, the main neotropical malaria vector.  

PubMed

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ?100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector-human and vector-parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi. PMID:23761445

Marinotti, Osvaldo; Cerqueira, Gustavo C; de Almeida, Luiz Gonzaga Paula; Ferro, Maria Ins Tiraboschi; Loreto, Elgion Lucio da Silva; Zaha, Arnaldo; Teixeira, Santuza M R; Wespiser, Adam R; Almeida E Silva, Alexandre; Schlindwein, Aline Daiane; Pacheco, Ana Carolina Landim; Silva, Artur Luiz da Costa da; Graveley, Brenton R; Walenz, Brian P; Lima, Bruna de Araujo; Ribeiro, Carlos Alexandre Gomes; Nunes-Silva, Carlos Gustavo; de Carvalho, Carlos Roberto; Soares, Clia Maria de Almeida; de Menezes, Claudia Beatriz Afonso; Matiolli, Cleverson; Caffrey, Daniel; Arajo, Demetrius Antonio M; de Oliveira, Diana Magalhes; Golenbock, Douglas; Grisard, Edmundo Carlos; Fantinatti-Garboggini, Fabiana; de Carvalho, Fabola Marques; Barcellos, Fernando Gomes; Prosdocimi, Francisco; May, Gemma; Azevedo Junior, Gilson Martins de; Guimares, Giselle Moura; Goldman, Gustavo Henrique; Padilha, Itcio Q M; Batista, Jacqueline da Silva; Ferro, Jesus Aparecido; Ribeiro, Jos M C; Fietto, Juliana Lopes Rangel; Dabbas, Karina Maia; Cerdeira, Louise; Agnez-Lima, Lucymara Fassarella; Brocchi, Marcelo; de Carvalho, Marcos Oliveira; Teixeira, Marcus de Melo; Diniz Maia, Maria de Mascena; Goldman, Maria Helena S; Cruz Schneider, Maria Paula; Felipe, Maria Sueli Soares; Hungria, Mariangela; Nicols, Marisa Fabiana; Pereira, Maristela; Montes, Martn Alejandro; Canto, Maurcio E; Vincentz, Michel; Rafael, Miriam Silva; Silverman, Neal; Stoco, Patrcia Hermes; Souza, Rangel Celso; Vicentini, Renato; Gazzinelli, Ricardo Tostes; Neves, Rogrio de Oliveira; Silva, Rosane; Astolfi-Filho, Spartaco; Maciel, Talles Eduardo Ferreira; Urmnyi, Turn P; Tadei, Wanderli Pedro; Camargo, Erney Plessmann; de Vasconcelos, Ana Tereza Ribeiro

2013-08-01

75

Targeted Trapping of Mosquito Vectors in the Chesapeake Bay Area of Maryland  

PubMed Central

Most adult mosquito surveillance in Maryland is performed using dry ice-baited or unbaited Centers for Disease Control (CDC) miniature light traps suspended ?1.5 m above the ground. However, standardized trapping methods may miss mosquito species involved in disease transmission cycles. During a 2-yr study, the effectiveness of the olfactory attractant 1-octen-3-ol alone and in combination with carbon dioxide was evaluated for collecting mosquito vector species. In addition, trap heights were examined to determine the optimal vertical placement to target various species. We evaluated the results during the second year by targeting selected species by using various habitatheightbait combinations. Although Culex erraticus Dyar & Knab and Anopheles quadrimaculatus Say were not successfully targeted, Culex salinarius Coquillett, Aedes vexans Meigen, Anopheles bradleyi/crucians King, Coquillettidia perturbans Walker, Aedes sollicitans Walker, and Aedes taeniorhynchus Wiedemann were preferentially captured using targeted trapping schemes. PMID:16619593

Shone, Scott M.; Glass, Gregory E.; Norris, Douglas E.

2014-01-01

76

Comparative responses of mosquito vectors of West Nile virus to light traps augmented with chemical attractant and to human hosts.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Scientists in the USA seek to develop Global Information Technology (GIS, GPS, remote sensing)-based systems that can be used to deploy sentinel traps for mosquito vectors and for the implementation and evaluation of mosquito control. Achieving this objective requires the development of methods for...

77

Coquillettidia (Culicidae, Diptera) mosquitoes are natural vectors of avian malaria in Africa  

PubMed Central

Background The mosquito vectors of Plasmodium spp. have largely been overlooked in studies of ecology and evolution of avian malaria and other vertebrates in wildlife. Methods Plasmodium DNA from wild-caught Coquillettidia spp. collected from lowland forests in Cameroon was isolated and sequenced using nested PCR. Female Coquillettidia aurites were also dissected and salivary glands were isolated and microscopically examined for the presence of sporozoites. Results In total, 33% (85/256) of mosquito pools tested positive for avian Plasmodium spp., harbouring at least eight distinct parasite lineages. Sporozoites of Plasmodium spp. were recorded in salivary glands of C. aurites supporting the PCR data that the parasites complete development in these mosquitoes. Results suggest C. aurites, Coquillettidia pseudoconopas and Coquillettidia metallica as new and important vectors of avian malaria in Africa. All parasite lineages recovered clustered with parasites formerly identified from several bird species and suggest the vectors capability of infecting birds from different families. Conclusion Identifying the major vectors of avian Plasmodium spp. will assist in understanding the epizootiology of avian malaria, including differences in this disease distribution between pristine and disturbed landscapes. PMID:19664282

2009-01-01

78

Mosquitoes (Diptera: Culicidae) and their relevance as disease vectors in the city of Vienna, Austria.  

PubMed

Mosquitoes (Diptera: Culicidae) are important vectors for a wide range of pathogenic organisms. As large parts of the human population in developed countries live in cities, the occurrence of vector-borne diseases in urban areas is of particular interest for epidemiologists and public health authorities. In this study, we investigated the mosquito occurrence in the city of Vienna, Austria, in order to estimate the risk of transmission of mosquito-borne diseases. Mosquitoes were captured using different sampling techniques at 17 sites in the city of Vienna. Species belonging to the Culex pipiens complex (78.8%) were most abundant, followed by Coquillettidia richiardii (10.2%), Anopheles plumbeus (5.4%), Aedes vexans (3.8%), and Ochlerotatus sticticus (0.7%). Individuals of the Cx. pipiens complex were found at 80.2% of the trap sites, while 58.8% of the trap sites were positive for Cq. richiardii and Ae. vexans. Oc. sticticus was captured at 35.3% of the sites, and An. plumbeus only at 23.5% of the trap sites. Cx. pipiens complex is known to be a potent vector and pathogens like West Nile virus (WNV), Usutu virus (USUV), Tahyna virus (TAHV), Sindbis virus (SINV), Plasmodium sp., and Dirofilaria repens can be transmitted by this species. Cq. richiardii is a known vector species for Batai virus (BATV), SINV, TAHV, and WNV, while Ae. vexans can transmit TAHV, USUV, WNV, and Dirofilaria repens. An. plumbeus and Oc. sticticus seem to play only a minor role in the transmission of vector-borne diseases in Vienna. WNV, which is already wide-spread in Europe, is likely to be the highest threat in Vienna as it can be transmitted by several of the most common species, has already been shown to pose a higher risk in cities, and has the possibility to cause severe illness. PMID:25468380

Lebl, Karin; Zittra, Carina; Silbermayr, Katja; Obwaller, Adelheid; Berer, Dominik; Brugger, Katharina; Walter, Melanie; Pinior, Beate; Fuehrer, Hans-Peter; Rubel, Franz

2015-02-01

79

Dengue vector mosquitos at a tourist attraction, Ko Samui, in 1995.  

PubMed

On Ko Samui, Thailand there were two epidemics of dengue hemorrhagic fever (DHF) in 1966 and 1967, followed by endemics up to 1994. Aedes aegypti and Aedes albopictus were the vectors. From January to July 1995, 51 cases of DHF were reported, out of these were many foreigners who still suffer from dengue fever and return home with negative impression. We carried out an entomological survey around the island and collected the mosquitos to detect dengue virus by digoxigenin-cDNA probe. The data revealed that Aedes aegypti and Aedes albopictus still were abundant and some were infected with dengue virus. Visual larval survey indices (HI, CI and BI) were 90.4, 61.3 and 301.3 respectively. Biting rate (BR) of Aedes mosquitos was high, the average indoor and outdoor BR were 9.7 and 100.8 mosquitos/man-hour. From 13 pools of mosquitos, 8 strains of dengue virus were detected (61.5%). The results may encourage the local authorities to improve vector surveillance and control before the famous island becomes an unpleasant island. PMID:9031420

Thavara, U; Tawatsin, A; Phan-Urai, P; Ngamsuk, W; Chansang, C; Liu, M; Li, Z

1996-03-01

80

Mosquitoes as Potential Bridge Vectors of Malaria Parasites from Non-Human Primates to Humans  

PubMed Central

Malaria is caused by Plasmodium parasites which are transmitted by mosquitoes. Until recently, human malaria was considered to be caused by human-specific Plasmodium species. Studies on Plasmodium parasites in non-human primates (NHPs), however, have identified parasite species in gorillas and chimpanzees that are closely related to human Plasmodium species. Moreover, P. knowlesi, long known as a parasite of monkeys, frequently infects humans. The requirements for such a cross-species exchange and especially the role of mosquitoes in this process are discussed, as the latter may act as bridge vectors of Plasmodium species between different primates. Little is known about the mosquito species that would bite both humans and NHPs and if so, whether humans and NHPs share the same Plasmodium vectors. To understand the vector-host interactions that can lead to an increased Plasmodium transmission between species, studies are required that reveal the nature of these interactions. Studying the potential role of NHPs as a Plasmodium reservoir for humans will contribute to the ongoing efforts of human malaria elimination, and will help to focus on critical areas that should be considered in achieving this goal. PMID:22701434

Verhulst, Niels O.; Smallegange, Renate C.; Takken, Willem

2012-01-01

81

Ecological niche modeling of potential West Nile virus vector mosquito species in Iowa.  

PubMed

Ecological niche modeling (ENM) algorithms, Maximum Entropy Species Distribution Modeling (Maxent) and Genetic Algorithm for Rule-set Prediction (GARP), were used to develop models in Iowa for three species of mosquito - two significant, extant West Nile virus (WNV) vectors (Culex pipiens L and Culex tarsalis Coquillett (Diptera: Culicidae)), and the nuisance mosquito, Aedes vexans Meigen (Diptera: Culicidae), a potential WNV bridge vector. Occurrence data for the three mosquito species from a state-wide arbovirus surveillance program were used in combination with climatic and landscape layers. Maxent successfully created more appropriate niche models with greater accuracy than GARP. The three Maxent species' models were combined and the average values were statistically compared to human WNV incidence at the census block group level. The results showed that the Maxent-modeled species' niches averaged together were a useful indicator of WNV human incidence in the state of Iowa. This simple method for creating probability distribution maps proved useful for understanding WNV dynamics and could be applied to the study of other vector-borne diseases. PMID:20874412

Larson, Scott R; DeGroote, John P; Bartholomay, Lyric C; Sugumaran, Ramanathan

2010-01-01

82

Determining the spatial autocorrelation of dengue vector populations: influences of mosquito sampling method, covariables, and vector control.  

PubMed

We investigated spatial autocorrelation of female Aedes aegypti L. mosquito abundance from BG-Sentinel trap and sticky ovitrap collections in Cairns, north Queensland, Australia. BG-Sentinel trap collections in 2010 show a significant spatial autocorrelation across the study site and over a smaller spatial extent, while sticky ovitrap collections only indicate a non-significant, weak spatial autocorrelation. The BG-Sentinel trap collections were suitable for spatial interpolation using ordinary kriging and cokriging techniques. The uses of Premise Condition Index and potential breeding container data have helped improve our prediction of vector abundance. Semiovariograms and prediction maps indicate that the spatial autocorrelation of mosquito abundance determined by BG-Sentinel traps extends farther compared to sticky ovitrap collections. Based on our data, fewer BG-Sentinel traps are required to represent vector abundance at a series of houses compared to sticky ovitraps. A lack of spatial structure was observed following vector control treatment in the area. This finding has implications for the design and costs of dengue vector surveillance programs. PMID:24820568

Azil, Aishah H; Bruce, David; Williams, Craig R

2014-06-01

83

Laboratory evaluation of Indian medicinal plants as repellents against malaria, dengue, and filariasis vector mosquitoes.  

PubMed

Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikungunya fever, West Nile virus, and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticides, in the present study, the repellent activity of crude hexane, ethyl acetate, benzene, chloroform, and methanol extracts of leaf of Erythrina indica and root of Asparagus racemosus were assayed for their repellency against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The crude extract was applied on a membrane used for membrane feeding of unfed mosquitoes in a 1-ft cage. About 50 unfed 3-4-day-old laboratory-reared pathogen-free strains of A. stephensi, A. aegypti, and C. quinquefasciatus were introduced in a 1-ft cage fitted with a membrane with blood for feeding with temperature maintained at 37C through circulating water bath maintained at 40-45C. Three concentrations (1.0, 2.0, and 5.0mg/cm(2)) of the crude extracts were evaluated. Repellents in E. indica afforded longer protection time against A. stephensi, A. aegypti, and C. quinquefasciatus than those in A. racemosus at 5.0mg/cm(2) concentration, and the mean complete protection time ranged from 120 to 210min with the different extracts tested. In this observation, these two plant crude extracts gave protection against mosquito bites; also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf extract of E. indica and root extract of A. racemosus have the potential to be used as an ideal eco-friendly approach for the control of mosquitoes. This is the first report on the mosquito repellent activity of the reported A. racemosus and E. indica plants. PMID:25399815

Govindarajan, Marimuthu; Sivakumar, Rajamohan

2015-02-01

84

The Developmental Transcriptome of the Mosquito Aedes aegypti, an Invasive Species and Major Arbovirus Vector  

PubMed Central

Mosquitoes are vectors of a number of important human and animal diseases. The development of novel vector control strategies requires a thorough understanding of mosquito biology. To facilitate this, we used RNA-seq to identify novel genes and provide the first high-resolution view of the transcriptome throughout development and in response to blood feeding in a mosquito vector of human disease, Aedes aegypti, the primary vector for Dengue and yellow fever. We characterized mRNA expression at 34 distinct time points throughout Aedes development, including adult somatic and germline tissues, by using polyA+ RNA-seq. We identify a total of 14,238 novel new transcribed regions corresponding to 12,597 new loci, as well as many novel transcript isoforms of previously annotated genes. Altogether these results increase the annotated fraction of the transcribed genome into long polyA+ RNAs by more than twofold. We also identified a number of patterns of shared gene expression, as well as genes and/or exons expressed sex-specifically or sex-differentially. Expression profiles of small RNAs in ovaries, early embryos, testes, and adult male and female somatic tissues also were determined, resulting in the identification of 38 new Aedes-specific miRNAs, and ~291,000 small RNA new transcribed regions, many of which are likely to be endogenous small-interfering RNAs and Piwi-interacting RNAs. Genes of potential interest for transgene-based vector control strategies also are highlighted. Our data have been incorporated into a user-friendly genome browser located at www.Aedes.caltech.edu, with relevant links to Vectorbase (www.vectorbase.org) PMID:23833213

Akbari, Omar S.; Antoshechkin, Igor; Amrhein, Henry; Williams, Brian; Diloreto, Race; Sandler, Jeremy; Hay, Bruce A.

2013-01-01

85

Mosquito Vector Diversity across Habitats in Central Thailand Endemic for Dengue and Other Arthropod-Borne Diseases  

PubMed Central

Recent years have seen the greatest ecological disturbances of our times, with global human expansion, species and habitat loss, climate change, and the emergence of new and previously-known infectious diseases. Biodiversity loss affects infectious disease risk by disrupting normal relationships between hosts and pathogens. Mosquito-borne pathogens respond to changing dynamics on multiple transmission levels and appear to increase in disturbed systems, yet current knowledge of mosquito diversity and the relative abundance of vectors as a function of habitat change is limited. We characterize mosquito communities across habitats with differing levels of anthropogenic ecological disturbance in central Thailand. During the 2008 rainy season, adult mosquito collections from 24 sites, representing 6 habitat types ranging from forest to urban, yielded 62,126 intact female mosquitoes (83,325 total mosquitoes) that were assigned to 109 taxa. Female mosquito abundance was highest in rice fields and lowest in forests. Diversity indices and rarefied species richness estimates indicate the mosquito fauna was more diverse in rural and less diverse in rice field habitats, while extrapolated estimates of true richness (Chao1 and ACE) indicated higher diversity in the forest and fragmented forest habitats and lower diversity in the urban. Culex sp. (Vishnui subgroup) was the most common taxon found overall and the most frequent in fragmented forest, rice field, rural, and suburban habitats. The distributions of species of medical importance differed significantly across habitat types and were always lowest in the intact, forest habitat. The relative abundance of key vector species, Aedes aegypti and Culex quinquefasciatus, was negatively correlated with diversity, suggesting that direct species interactions and/or habitat-mediated factors differentially affecting invasive disease vectors may be important mechanisms linking biodiversity loss to human health. Our results are an important first step for understanding the dynamics of mosquito vector distributions under changing environmental features across landscapes of Thailand. PMID:24205420

Thongsripong, Panpim; Green, Amy; Kittayapong, Pattamaporn; Kapan, Durrell; Wilcox, Bruce; Bennett, Shannon

2013-01-01

86

Culex gelidus: An emerging mosquito vector with potential to transmit multiple virus infections.  

PubMed

Culex gelidus Theobald has emerged as a major vector of Japanese encephalitis virus (JEV) in India, Southeast Asian countries and Australia. The species has expanded its geographic distribution from the Indian subcontinent to Japan, China, other Southeast Asian countries, Island nations in Australasian region and Australia. In recent years, a sudden increase in its population especially in the urban and sub-urban areas has been observed in several countries, thus, becoming a dominant mosquito species. The virus has been repeatedly isolated from from different geographical locations making it one of the most important vectors of JEV. Apart from JEV, other viruses of public health importance, viz. Getah, Ross River (RRV), Sindbis and Tembusu have been isolated from the mosquito. Experimental studies have shown that the mosquito Cx. qelidus is highly competent to transmit West Nile, Kunjin and Murray valley encephalitis viruses with infection and transmission rates of >80 and >50%, respectively for each virus. The species is also found competent to transmit RRV, but at a lower rate. Experimental studies have shown that the species is susceptible to chikungunya, Chandipura and Chittoor (Batai) viruses. Development of resistance to DDT and malathion has also been detected in the species recently. The invasive nature, ability to breed both in fresh and dirty waters, development of resistance to insecticides, high anthropophily and its potential to transmit important human viruses pose an increased threat of viral encephalitis in India and Oriental region especially in the light of explosive increase in its population. PMID:25540955

Sudeep, A B

2014-01-01

87

Vector roles of Fennoscandian mosquitoes attracted to mammals, birds and frogs.  

PubMed

1. Mosquitoes were sampled with five suction traps, from May to October 1983, at a forest site in south-central Sweden. 2. Twenty-three species of mosquitoes were identified among the total of 3108 females collected: 4% of them in an unbaited trap, 3% in a trap baited with two frogs, 24% with a guinea-pig, 28% with a hen and 40% in a trap baited with a rabbit. 3. The dominant species of Culicidae trapped were 39% Aedes communis (De Geer), 21% Ae. cinereus Meigen, 14% Coquillettidia richiardii (Ficalbi), 8% Ae. punctor (Kirby) and 4% Culiseta morsitans (Theobald). 4. Aedes annulipes (Meigen), Ae. cantans (Meigen), Ae. cinereus, Ae. communis and Ae. punctor were mostly attracted to the rabbit, whereas Culiseta morsitans, Culex pipiens L. and/or Cx torrentium Martini were strongly ornithophilic. 5. Based on these and previously published data the ecological and behavioural potential of the mosquitoes to transmit Sindbis, Inkoo, Tahyna and Batai viruses, tularaemia (caused by Francisella tularensis) and Ixodes-borne borreliosis (caused by Borrelia burgdorferi) in Fennoscandia is discussed. 6. The data support the hypothesis that Sindbis virus, which is enzootic in bird populations in Fennoscandia, is vectored between birds by Cx pipiens/torrentium and Cs. morsitans, and that abundant Aedes spp., particularly Ae. cinereus, which feed on both birds and mammals, are primary link vectors from infective birds to man and other mammals. PMID:1983455

Jaenson, T G

1990-04-01

88

Development of a population suppression strain of the human malaria vector mosquito, Anopheles stephensi  

PubMed Central

Background Transgenic mosquito strains are being developed to contribute to the control of dengue and malaria transmission. One approach uses genetic manipulation to confer conditional, female-specific dominant lethality phenotypes. Engineering of a female-specific flightless phenotype provides a sexing mechanism essential for male-only mosquito, release approaches that result in population suppression of target vector species. Methods An approach that uses a female-specific gene promoter and antibiotic-repressible lethal factor to produce a sex-specific flightless phenotype was adapted to the human malaria vector, Anopheles stephensi. Transposon- and site-specific recombination-mediated technologies were used to generate a number of transgenic An. stephensi lines that when combined through mating produced the phenotype of flight-inhibited females and flight-capable males. Results The data shown here demonstrate the successful engineering of a female-specific flightless phenotype in a malaria vector. The flightless phenotype was repressible by the addition of tetracycline to the larval diet. This conditional phenotype allows the rearing of the strains under routine laboratory conditions. The minimal level of tetracycline that rescues the flightless phenotype is higher than that found as an environmental contaminant in circumstances where there is intensive use of antibiotics. Conclusions These studies support the further development of flightless female technology for applications in malaria control programmes that target the vectors. PMID:23622561

2013-01-01

89

[The relationship between mosquito vectors and aquatic birds in the potential transmission of 2 arboviruses].  

PubMed

The authors studied for two years the role of the chicks of aquatic birds in the arboviral cycles in coastal lagoons in central Panama in order to determine the relation between Culex (Melanoconion) ocossa and Mansonia (Mansonia) dyari mosquitoes in the transmission and dissemination of the viruses of Saint Louis Encephalitis (SLE) and Venezuelan Equine Encephalitis (VEE). Mosquitoes were captured every fifteen days on two consecutive nights to isolate the virus, using light traps (CDC) and baited traps. The attempts to isolate the virus were made using Vero cell cultures and the determination of antibodies was performed. The results of the serologic tests seem to indicate that four bird species: the ex (?) heron (Bubulcus ibis), the American heron (Casmerodius albus), the spoon-billed duck (Cochlearius cochlearius) and the needle crow (Anhinga anhinga) could function as intermediate hosts in the transmission cycle of SLE. Two species, the ibis (Endocimus albus) and the spoon-billed duck (Cochlearius cochlearius) could also be intermediate hosts of VEE in the coastal lagoons of Panama. The presence of antibodies in chicks could indicate an infection acquired recently, after their birth, in this area. The VEE virus was recovered from blood filled mosquitoes which had fed on a spoon-billed duck probably infected and exposed in a Trinidad #10 trap. No SLE virus was isolated. Other unknown viruses were isolated from mosquitoes selected for these studies, such as C. ocossa and M. dyari. The results obtained with these studies indicate the need for more studies utilizing new field techniques in order to establish a link between SLE and VEE, the vector mosquitoes and the aquatic birds in the coastal lagoons of the area under investigation. PMID:8101009

Adames, A J; Dutary, B; Tejera, H; Adames, E; Galindo, P

1993-05-01

90

Ambient temperature and dietary supplementation interact to shape mosquito vector competence for malaria.  

PubMed

The extent to which environmental factors influence the ability of Anopheles mosquitoes to transmit malaria parasites remains poorly explored. Environmental variation, such as change in ambient temperature, will not necessarily influence the rates of host and parasite processes equivalently, potentially resulting in complex effects on infection outcomes. As proof of principle, we used Anopheles stephensi and the rodent malaria parasite, Plasmodium yoelii, to examine the effects of a range of constant temperatures on one aspect of host defense (detected as alterations in expression of nitric oxide synthase gene - NOS) to parasite infection. We experimentally boosted mosquito midgut immunity to infection through dietary supplementation with the essential amino acid l-Arginine (l-Arg), which increases midgut nitric oxide (NO) levels by infection-induced NOS catalysis in A. stephensi. At intermediate temperatures, supplementation reduced oocyst prevalence, oocyst intensity, and sporozoite prevalence suggesting that the outcome of parasite infection was potentially dependent upon the rate of NOS-mediated midgut immunity. At low and high temperature extremes, however, infection was severely constrained irrespective of supplementation. The effects of l-Arg appeared to be mediated by NO-dependent negative feedback on NOS expression, as evidenced by depressed NOS expression in l-Arg treated groups at temperatures where supplementation decreased parasite infection. These results suggest the need to consider the direct (e.g. effects of mosquito body temperature on parasite physiology) and indirect effects (e.g. mediated through changes in mosquito physiology/immunity) of environmental factors on mosquito-malaria interactions in order to understand natural variation in vector competence. PMID:24911425

Murdock, Courtney C; Blanford, Simon; Luckhart, Shirley; Thomas, Matthew B

2014-08-01

91

miRNA Genes of an Invasive Vector Mosquito, Aedes albopictus  

PubMed Central

Aedes albopictus, a vector of Dengue and Chikungunya viruses, is a robust invasive species in both tropical and temperate environments. MicroRNAs (miRNAs) regulate gene expression and biological processes including embryonic development, innate immunity and infection. While a number of miRNAs have been discovered in some mosquitoes, no comprehensive effort has been made to characterize them from different developmental stages from a single species. Systematic analysis of miRNAs in Ae. albopictus will improve our understanding of its basic biology and inform novel strategies to prevent virus transmission. Between 1014 million Illumina sequencing reads per sample were obtained from embryos, larvae, pupae, adult males, sugar-fed and blood-fed adult females. A total of 119 miRNA genes represented by 215 miRNA or miRNA star (miRNA*) sequences were identified, 15 of which are novel. Eleven, two, and two of the newly-discovered miRNA genes appear specific to Aedes, Culicinae, and Culicidae, respectively. A number of miRNAs accumulate predominantly in one or two developmental stages and the large number that showed differences in abundance following a blood meal likely are important in blood-induced mosquito biology. Gene Ontology (GO) analysis of the targets of all Ae. albopictus miRNAs provides a useful starting point for the study of their functions in mosquitoes. This study is the first systematic analysis of miRNAs based on deep-sequencing of small RNA samples of all developmental stages of a mosquito species. A number of miRNAs are related to specific physiological states, most notably, pre- and post-blood feeding. The distribution of lineage-specific miRNAs is consistent with mosquito phylogeny and the presence of a number of Aedes-specific miRNAs likely reflects the divergence between the Aedes and Culex genera. PMID:23840875

Zheng, Peiming; Chen, Maoshan; James, Anthony A.; Chen, Xiaoguang; Tu, Zhijian

2013-01-01

92

MIRO and IRbase: IT Tools for the Epidemiological Monitoring of Insecticide Resistance in Mosquito Disease Vectors  

PubMed Central

Background Monitoring of insect vector populations with respect to their susceptibility to one or more insecticides is a crucial element of the strategies used for the control of arthropod-borne diseases. This management task can nowadays be achieved more efficiently when assisted by IT (Information Technology) tools, ranging from modern integrated databases to GIS (Geographic Information System). Here we describe an application ontology that we developed de novo, and a specially designed database that, based on this ontology, can be used for the purpose of controlling mosquitoes and, thus, the diseases that they transmit. Methodology/Principal Findings The ontology, named MIRO for Mosquito Insecticide Resistance Ontology, developed using the OBO-Edit software, describes all pertinent aspects of insecticide resistance, including specific methodology and mode of action. MIRO, then, forms the basis for the design and development of a dedicated database, IRbase, constructed using open source software, which can be used to retrieve data on mosquito populations in a temporally and spatially separate way, as well as to map the output using a Google Earth interface. The dependency of the database on the MIRO allows for a rational and efficient hierarchical search possibility. Conclusions/Significance The fact that the MIRO complies with the rules set forward by the OBO (Open Biomedical Ontologies) Foundry introduces cross-referencing with other biomedical ontologies and, thus, both MIRO and IRbase are suitable as parts of future comprehensive surveillance tools and decision support systems that will be used for the control of vector-borne diseases. MIRO is downloadable from and IRbase is accessible at VectorBase, the NIAID-sponsored open access database for arthropod vectors of disease. PMID:19547750

Dialynas, Emmanuel; Topalis, Pantelis; Vontas, John; Louis, Christos

2009-01-01

93

Genome analysis of a major urban malaria vector mosquito, Anopheles stephensi.  

PubMed

Background Anopheles stephensi is the key vector of malaria throughout the Indian subcontinent and Middle East and an emerging model for molecular and genetic studies of mosquito-parasite interactions. The type form of the species is responsible for the majority of urban malaria transmission across its range.ResultsHere, we report the genome sequence and annotation of the Indian strain of the type form of An. stephensi. The 221 Mb genome assembly represents more than 92% of the entire genome and was produced using a combination of 454, Illumina, and PacBio sequencing. Physical mapping assigned 62% of the genome onto chromosomes, enabling chromosome-based analysis. Comparisons between An. stephensi and An. gambiae reveal that the rate of gene order reshuffling on the X chromosome was three times higher than that on the autosomes. An. stephensi has more heterochromatin in pericentric regions but less repetitive DNA in chromosome arms than An. gambiae. We also identify a number of Y-chromosome contigs and BACs. Interspersed repeats constitute 7.1% of the assembled genome while LTR retrotransposons alone comprise more than 49% of the Y contigs. RNA-seq analyses provide new insights into mosquito innate immunity, development, and sexual dimorphism.ConclusionsThe genome analysis described in this manuscript provides a resource and platform for fundamental and translational research into a major urban malaria vector. Chromosome-based investigations provide unique perspectives on Anopheles chromosome evolution. RNA-seq analysis and studies of immunity genes offer new insights into mosquito biology and mosquito-parasite interactions. PMID:25244985

Jiang, Xiaofang; Peery, Ashley; Hall, A; Sharma, Atashi; Chen, Xiao-Guang; Waterhouse, Robert M; Komissarov, Aleksey; Riehl, Michelle M; Shouche, Yogesh; Sharakhova, Maria V; Lawson, Dan; Pakpour, Nazzy; Arensburger, Peter; Davidson, Victoria L M; Eiglmeier, Karin; Emrich, Scott; George, Phillip; Kennedy, Ryan C; Mane, Shrinivasrao P; Maslen, Gareth; Oringanje, Chioma; Qi, Yumin; Settlage, Robert; Tojo, Marta; Tubio, Jose M C; Unger, Maria F; Wang, Bo; Vernick, Kenneth D; Ribeiro, Jose M C; James, Anthony A; Michel, Kristin; Riehle, Michael A; Luckhart, Shirley; Sharakhov, Igor V; Tu, Zhijian

2014-09-23

94

Habitat Segregation of Mosquito Arbovirus Vectors in South Florida  

PubMed Central

Oviposition traps set in rural to urban environments in three south Florida counties were colonized predominantly by Culex quinquefasciatus Say (35.1%), Aedes albopictus (Skuse) (34.5%), Aedes aegypti (L.) (23.8%), and Culex nigripalpus Theobald (6.6%) during 1 yr of monthly sampling. Significant differences were detected among counties for abundances of Cx. quinquefasciatus and for percentage composition of that species and Ae. albopictus. Aerial images of habitats around each collection site were digitized, and coverages by each of 16 habitat variables were recorded. Abundances of Ae. aegypti were positively related to habitat variables associated with urbanization and negatively correlated to those reflecting rural characteristics. Multiple regression models of habitat selection explained similar proportions of variances in abundance of Ae. aegypti and Ae. albopictus, but signs of significant variables were opposite for these two species. No consistent trends of habitat associations were observed among counties for the two Culex spp. Co-occurrences of the four species in individual traps depended on container type (tub versus cup), and, for Aedes spp. with Culex spp., county. The results underscore the importance of scale in evaluating habitat selection and the utility of quantifiable habitat characteristics of intermediate scale to identify site characteristics favored by the arboviral vectors Ae. aegypti and Ae. albopictus. PMID:17162945

REY, JORGE R.; NISHIMURA, NAOYA; WAGNER, BILLI; BRAKS, MARIETA A.H.; OCONNELL, SHEILA M.; LOUNIBOS, L. PHILIP

2007-01-01

95

Early warning of West Nile virus mosquito vector: climate and land use models successfully explain phenology and abundance of Culex pipiens mosquitoes in north-western Italy  

PubMed Central

Background West Nile Virus (WNV) is an emerging global health threat. Transmission risk is strongly related to the abundance of mosquito vectors, typically Culex pipiens in Europe. Early-warning predictors of mosquito population dynamics would therefore help guide entomological surveillance and thereby facilitate early warnings of transmission risk. Methods We analysed an 11-year time series (2001 to 2011) of Cx. pipiens mosquito captures from the Piedmont region of north-western Italy to determine the principal drivers of mosquito population dynamics. Linear mixed models were implemented to examine the relationship between Cx. pipiens population dynamics and environmental predictors including temperature, precipitation, Normalized Difference Water Index (NDWI) and the proximity of mosquito traps to urban areas and rice fields. Results Warm temperatures early in the year were associated with an earlier start to the mosquito season and increased season length, and later in the year, with decreased abundance. Early precipitation delayed the start and shortened the length of the mosquito season, but increased total abundance. Conversely, precipitation later in the year was associated with a longer season. Finally, higher NDWI early in the year was associated with an earlier start to the season and increased season length, but was not associated with abundance. Proximity to rice fields predicted higher total abundance when included in some models, but was not a significant predictor of phenology. Proximity to urban areas was not a significant predictor in any of our models. Predicted variations in start of the season and season length ranged from one to three weeks, across the measured range of variables. Predicted mosquito abundance was highly variable, with numbers in excess of 1000 per trap per year when late season temperatures were low (average 21C) to only 150 when late season temperatures were high (average 30C). Conclusions Climate data collected early in the year, in conjunction with local land use, can be used to provide early warning of both the timing and magnitude of mosquito outbreaks. This potentially allows targeted mosquito control measures to be implemented, with implications for prevention and control of West Nile Virus and other mosquito borne diseases. PMID:24924622

2014-01-01

96

Circulation of Japanese Encephalitis Virus in Pigs and Mosquito Vectors within Can Tho City, Vietnam  

PubMed Central

Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing encephalitis in humans and reproductive disorder in pigs. JEV is present in large parts of Asia, where urbanization is high. Households within and outside Can Tho city, South Vietnam, were selected to monitor circulation of JEV. A nested RT-PCR was established to detect the presence of JEV in mosquitoes whereas sera from pigs belonging to households within the province were analyzed for the presence of antibodies to JEV. A total of 7885 mosquitoes were collected and divided into 352 pools whereof seven were JEV-positive, six of which were collected within the city. Fragments from four pools clustered with JEV genotype III and three with genotype I. Of the 43 pigs sampled inside the city 100% had JEV antibodies. Our study demonstrates exposure to JEV in pigs, and co-circulation of JEV genotype I and III in mosquitoes within an urban environment in South Vietnam. Thus, although JEV has mainly been considered a rural disease, the potential for transmission in urban areas cannot be ignored. PMID:23593520

Lindahl, Johanna F.; Sthl, Karl; Chirico, Jan; Boqvist, Sofia; Thu, Ho Thi Viet; Magnusson, Ulf

2013-01-01

97

Circulation of Japanese encephalitis virus in pigs and mosquito vectors within Can Tho city, Vietnam.  

PubMed

Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing encephalitis in humans and reproductive disorder in pigs. JEV is present in large parts of Asia, where urbanization is high. Households within and outside Can Tho city, South Vietnam, were selected to monitor circulation of JEV. A nested RT-PCR was established to detect the presence of JEV in mosquitoes whereas sera from pigs belonging to households within the province were analyzed for the presence of antibodies to JEV. A total of 7885 mosquitoes were collected and divided into 352 pools whereof seven were JEV-positive, six of which were collected within the city. Fragments from four pools clustered with JEV genotype III and three with genotype I. Of the 43 pigs sampled inside the city 100% had JEV antibodies. Our study demonstrates exposure to JEV in pigs, and co-circulation of JEV genotype I and III in mosquitoes within an urban environment in South Vietnam. Thus, although JEV has mainly been considered a rural disease, the potential for transmission in urban areas cannot be ignored. PMID:23593520

Lindahl, Johanna F; Sthl, Karl; Chirico, Jan; Boqvist, Sofia; Thu, Ho Thi Viet; Magnusson, Ulf

2013-01-01

98

Mosquito communities with trap height and urban-rural gradient in Adelaide, South Australia: implications for disease vector surveillance.  

PubMed

Understanding the factors influencing mosquito distribution is important for effective surveillance and control of nuisance and disease vector mosquitoes. The goal of this study was to determine how trap height and distance to the city center influenced the abundance and species of mosquitoes collected in Adelaide, South Australia. Mosquito communities were sampled at two heights (<2 m and ~10 m) along an urban-rural gradient. A total of 5,133 mosquitoes was identified over 176 trap nights. Aedes notoscriptus, Ae. vigilax, and Culex molestus were all more abundant in lower traps while Cx. quinquefasciatus (an ornithophilic species) was found to be more abundant in high traps. Distance to city center correlated strongly with the abundance of Ae. vigilax, Ae. camptorhynchus, Cx. globocoxitus, and Cx. molestus, all of which were most common at the sites farthest from the city and closest to the saltmarsh. Overall, the important disease vectors in South Australia (Ae. vigilax, Ae. camptorhynchus, Ae. notoscriptus, and Cx. annulirostris) were more abundant in low traps farthest from the city and closest to the saltmarsh. The current mosquito surveillance practice of setting traps within two meters of the ground is effective for sampling populations of the important disease vector species in South Australia. PMID:24820555

Johnston, Emily; Weinstein, Phillip; Slaney, David; Flies, Andrew S; Fricker, Stephen; Williams, Craig

2014-06-01

99

The Dengue Virus Mosquito Vector Aedes aegypti at High Elevation in Mxico  

PubMed Central

Mxico has cities (e.g., Mxico City and Puebla City) located at elevations > 2,000 m and above the elevation ceiling below which local climates allow the dengue virus mosquito vector Aedes aegypti to proliferate. Climate warming could raise this ceiling and place high-elevation cities at risk for dengue virus transmission. To assess the elevation ceiling for Ae. aegypti and determine the potential for using weather/climate parameters to predict mosquito abundance, we surveyed 12 communities along an elevation/climate gradient from Veracruz City (sea level) to Puebla City (?2,100 m). Ae. aegypti was commonly encountered up to 1,700 m and present but rare from 1,700 to 2,130 m. This finding extends the known elevation range in Mxico by > 300 m. Mosquito abundance was correlated with weather parameters, including temperature indices. Potential larval development sites were abundant in Puebla City and other high-elevation communities, suggesting that Ae. aegypti could proliferate should the climate become warmer. PMID:22987656

Lozano-Fuentes, Saul; Hayden, Mary H.; Welsh-Rodriguez, Carlos; Ochoa-Martinez, Carolina; Tapia-Santos, Berenice; Kobylinski, Kevin C.; Uejio, Christopher K.; Zielinski-Gutierrez, Emily; Monache, Luca Delle; Monaghan, Andrew J.; Steinhoff, Daniel F.; Eisen, Lars

2012-01-01

100

Dynamics of the Popcorn Wolbachia Infection in Outbred Aedes aegypti Informs Prospects for Mosquito Vector Control  

PubMed Central

Forty percent of the world's population is at risk of contracting dengue virus, which produces dengue fever with a potentially fatal hemorrhagic form. The wMelPop Wolbachia infection of Drosophila melanogaster reduces life span and interferes with viral transmission when introduced into the mosquito Aedes aegypti, the primary vector of dengue virus. Wolbachia has been proposed as an agent for preventing transmission of dengue virus. Population invasion by Wolbachia depends on levels of cytoplasmic incompatibility, fitness effects, and maternal transmission. Here we characterized these traits in an outbred genetic background of a potential target population of Ae. aegypti using two crossing schemes. Cytoplasmic incompatibility was strong in this background, and the maternal transmission rate of Wolbachia was high. The infection substantially reduced longevity of infected adult females, regardless of whether adults came from larvae cultured under high or low levels of nutrition or density. The infection reduced the viability of diapausing and nondiapausing eggs. Viability was particularly low when eggs were laid by older females and when diapausing eggs had been stored for a few weeks. The infection affected mosquito larval development time and adult body size under different larval nutrition levels and densities. The results were used to assess the potential for wMelPop-CLA to invade natural populations of Ae. aegypti and to develop recommendations for the maintenance of fitness in infected mosquitoes that need to compete against field insects. PMID:21135075

Yeap, H. L.; Mee, P.; Walker, T.; Weeks, A. R.; O'Neill, S. L.; Johnson, P.; Ritchie, S. A.; Richardson, K. M.; Doig, C.; Endersby, N. M.; Hoffmann, A. A.

2011-01-01

101

Odor Coding in the Maxillary Palp of the Malaria Vector Mosquito Anopheles gambiae  

PubMed Central

Summary Background Many species of mosquitoes, including the major malaria vector Anopheles gambiae, utilize carbon dioxide (CO2) and 1-octen-3-ol as olfactory cues in host-seeking behaviors that underlie their vectorial capacity. However, the molecular and cellular basis of such olfactory responses remains largely unknown. Results Here, we use molecular and physiological approaches coupled with systematic functional analyses to define the complete olfactory sensory map of the An. gambiae maxillary palp, an olfactory appendage that mediates the detection of these compounds. In doing so, we identify three olfactory receptor neurons (ORNs) that are organized in stereotyped triads within the maxillary-palp capitate-peg-sensillum population. One ORN is CO2-responsive and characterized by the coexpression of three receptors that confer CO2 responses, whereas the other ORNs express characteristic odorant receptors (AgORs) that are responsible for their in vivo olfactory responses. Conclusions Our results describe a complete and highly concordant map of both the molecular and cellular olfactory components on the maxillary palp of the adult female An. gambiae mosquito. These results also facilitate the understanding of how An. gambiae mosquitoes sense olfactory cues that might be exploited to compromise their ability to transmit malaria. PMID:17764944

Lu, Tan; Qiu, Yu Tong; Wang, Guirong; Kwon, Jae Young; Rutzler, Michael; Kwon, Hyung-Wook; Pitts, R. Jason; van Loon, Joop J.A.; Takken, Willem; Carlson, John R.; Zwiebel, Laurence J.

2011-01-01

102

Efficacy of Thai herbal essential oils as green repellent against mosquito vectors.  

PubMed

Repellency activity of Thai essential oils derived from ylang ylang (Cananga odorata (Lamk.) Hook.f. & Thomson: Annonaceae) and lemongrass (Cymbopogon citratus (DC.) Stapf: Poaceae) were tested against two mosquito vectors, Aedes aegypti (L.) and Culex quinquefasciatus (Say). There were compared with two chemical repellents (DEET 20% w/w; Sketolene Shield() and IR3535, ethyl butylacetylaminopropionate 12.5% w/w; Johnson's Baby Clear Lotion Anti-Mosquito()). Each herbal repellent was applied in three diluents; coconut oil, soybean oil and olive oil at 0.33?l/cm(2) on the forearm of volunteers. All herbal repellent exhibited higher repellent activity than IR3535 12.5% w/w, but lower repellent activity than DEET 20% w/w. The C. odorata oil in coconut oil exhibited excellent activity with 98.9% protection from bites of A. aegypti for 88.710.4min. In addition, C. citratus in olive oil showed excellent activity with 98.8% protection from bites of C. quinquefasciatus for 170.09.0min. While, DEET 20% w/w gave protection for 155.07.1-182.012.2min and 98.5% protection from bites of two mosquito species. However, all herbal repellent provided lower repellency activity (97.4-98.9% protection for 10.5-88.7min) against A. aegypti than C. quinquefasciatus (98.3-99.2% protection for 60-170min). Our data exhibited that C. odorata oil and C. citratus oil are suitable to be used as green repellents for mosquito control, which are safe for humans, domestic animals and environmental friendly. PMID:25438256

Soonwera, Mayura; Phasomkusolsil, Siriporn

2015-02-01

103

Simulation Modelling of Population Dynamics of Mosquito Vectors for Rift Valley Fever Virus in a Disease Epidemic Setting  

PubMed Central

Background Rift Valley Fever (RVF) is weather dependent arboviral infection of livestock and humans. Population dynamics of mosquito vectors is associated with disease epidemics. In our study, we use daily temperature and rainfall as model inputs to simulate dynamics of mosquito vectors population in relation to disease epidemics. Methods/Findings Time-varying distributed delays (TVDD) and multi-way functional response equations were implemented to simulate mosquito vectors and hosts developmental stages and to establish interactions between stages and phases of mosquito vectors in relation to vertebrate hosts for infection introduction in compartmental phases. An open-source modelling platforms, Universal Simulator and Qt integrated development environment were used to develop models in C++ programming language. Developed models include source codes for mosquito fecundity, host fecundity, water level, mosquito infection, host infection, interactions, and egg time. Extensible Markup Language (XML) files were used as recipes to integrate source codes in Qt creator with Universal Simulator plug-in. We observed that Floodwater Aedines and Culicine population continued to fluctuate with temperature and water level over simulation period while controlled by availability of host for blood feeding. Infection in the system was introduced by floodwater Aedines. Culicines pick infection from infected host once to amplify disease epidemic. Simulated mosquito population show sudden unusual increase between December 1997 and January 1998 a similar period when RVF outbreak occurred in Ngorongoro district. Conclusion/Significance Findings presented here provide new opportunities for weather-driven RVF epidemic simulation modelling. This is an ideal approach for understanding disease transmission dynamics towards epidemics prediction, prevention and control. This approach can be used as an alternative source for generation of calibrated RVF epidemics data in different settings. PMID:25259792

Mweya, Clement N.; Holst, Niels; Mboera, Leonard E. G.; Kimera, Sharadhuli I.

2014-01-01

104

Visual arrestins in olfactory pathways of Drosophila and the malaria vector mosquito Anopheles gambiae  

PubMed Central

Arrestins are important components for desensitization of G protein-coupled receptor cascades that mediate neurotransmission as well as olfactory and visual sensory reception. We have isolated AgArr1, an arrestin-encoding cDNA from the malaria vector mosquito, Anopheles gambiae, where olfaction is critical for vectorial capacity. Analysis of AgArr1 expression revealed an overlap between chemosensory and photoreceptor neurons. Furthermore, an examination of previously identified arrestins from Drosophila melanogaster exposed similar bimodal expression, and Drosophila arrestin mutants demonstrate impaired electrophysiological responses to olfactory stimuli. Thus, we show that arrestins in Drosophila are required for normal olfactory physiology in addition to their previously described role in visual signaling. These findings suggest that individual arrestins function in both olfactory and visual pathways in Dipteran insects; these genes may prove useful in the design of control strategies that target olfactory-dependent behaviors of insect disease vectors. PMID:11792843

Merrill, C. E.; Riesgo-Escovar, J.; Pitts, R. J.; Kafatos, F. C.; Carlson, J. R.; Zwiebel, L. J.

2002-01-01

105

Larvicidal Activity of Cassia occidentalis (Linn.) against the Larvae of Bancroftian Filariasis Vector Mosquito Culex quinquefasciatus  

PubMed Central

Background & Objectives. The plan of this work was to study the larvicidal activity of Cassia occidentalis (Linn.) against the larvae of Culex quinquefasciatus. These larvae are the most significant vectors. They transmit the parasites and pathogens which cause a deadly disease like filariasis, dengue, yellow fever, malaria, Japanese encephalitis, chikungunya, and so forth, which are considered harmful towards the population in tropic and subtropical regions. Methods. The preliminary laboratory trail was undertaken to determine the efficacy of petroleum ether and N-butanol extract of dried whole plant of Cassia occidentalis (Linn.) belonging to the family Caesalpiniaceae at various concentrations against the late third instar larvae of Culex quinquefasciatus by following the WHO guidelines. Results. The results suggest that 100% mortality effect of petroleum ether and N-butanol extract of Cassia occidentalis (Linn.) was observed at 200 and 300?ppm (parts per million). The results obviously showed use of plants in insect control as an alternative method for minimizing the noxious effect of some pesticide compounds on the environment. Thus the extract of Cassia occidentalis (Linn.) is claimed as more selective and biodegradable agent. Conclusion. This study justified that plant Cassia occidentalis (Linn.) has a realistic mortality result for larvae of filarial vector. This is safe to individual and communities against mosquitoes. It is a natural weapon for mosquito control. PMID:24688786

Kumar, Deepak; Chawla, Rakesh; Dhamodaram, P.; Balakrishnan, N.

2014-01-01

106

Molecular Characterization of Larval Peripheral Thermosensory Responses of the Malaria Vector Mosquito Anopheles gambiae  

PubMed Central

Thermosensation provides vital inputs for the malaria vector mosquito, Anopheles gambiae which utilizes heat-sensitivity within a broad spectrum of behaviors, most notably, the localization of human hosts for blood feeding. In this study, we examine thermosensory behaviors in larval-stage An. gambiae, which as a result of their obligate aquatic habitats and importance for vectorial capacity, represents an opportunistic target for vector control as part of the global campaign to eliminate malaria. As is the case for adults, immature mosquitoes respond differentially to a diverse array of external heat stimuli. In addition, larvae exhibit a striking phenotypic plasticity in thermal-driven behaviors that are established by temperature at which embryonic development occurs. Within this spectrum, RNAi-directed gene-silencing studies provide evidence for the essential role of the Transient Receptor Potential sub-family A1 (TRPA1) channel in mediating larval thermal-induced locomotion and thermal preference within a discrete upper range of ambient temperatures. PMID:23940815

Liu, Chao; Zwiebel, Laurence J.

2013-01-01

107

Evaluation of larvicidal activity of Pongamia pinnata extracts against three mosquito vectors  

PubMed Central

Objective To evaluate the mosquito larvicidal activity of Pongamia pinnata (P. pinnata) extracts against three mosquito vectors. Methods The methanol and hydroalcohol extracts of bark part of P. pinnata L were tested against fourth instar larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi. The mortality was observed 24 h and 48 h after treatment, data was subjected to probit analysis to determine lethal concentration (LC50 and LC90) to kill 50 and 90 percent of treated larvae of tested species. Results The larval mortality was found in both methanol and hydroalcohol extracts of P. pinnata against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi with LC50 values of 84.8, 118.2 and 151.7 ppm; 97.7, 128.3 and 513 ppm. The highest larval mortality was found in methanol extract of P. pinnata when comparable to the hydroalcohol extract. Conclusions These results suggest that both methanol and hyrdoalcohol extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors. This could lead to isolation of novel natural larvicidal compounds.

Kolli, Guna Ranjan; Balakrishnan; Vijayan; Sundararajan, Raja

2013-01-01

108

Antipathogen genes and the replacement of disease-vectoring mosquito populations: a model-based evaluation  

PubMed Central

Recently, genetic strategies aimed at controlling populations of disease-vectoring mosquitoes have received considerable attention as alternatives to traditional measures. Theoretical studies have shown that female-killing (FK), antipathogen (AP), and reduce and replace (R&R) strategies can each decrease the number competent vectors. In this study, we utilize a mathematical model to evaluate impacts on competent Aedes aegypti populations of FK, AP, and R&R releases as well as hybrid strategies that result from combinations of these three approaches. We show that while the ordering of efficacy of these strategies depends upon population life history parameters, sex ratio of releases, and switch time in combination strategies, AP-only and R&R/AP releases typically lead to the greatest long-term reduction in competent vectors. R&R-only releases are often less effective at long-term reduction of competent vectors than AP-only releases or R&R/AP releases. Furthermore, the reduction in competent vectors caused by AP-only releases is easier to maintain than that caused by FK-only or R&R-only releases even when the AP gene confers a fitness cost. We discuss the roles that density dependence and inclusion of females play in the order of efficacy of the strategies. We anticipate that our results will provide added impetus to continue developing AP strategies.

Robert, Michael A; Okamoto, Kenichi W; Gould, Fred; Lloyd, Alun L

2014-01-01

109

Evaluation of a temperate climate mosquito, Ochlerotatus detritus (=Aedes detritus), as a potential vector of Japanese encephalitis virus.  

PubMed

The U.K. has not yet experienced a confirmed outbreak of mosquito-borne virus transmission to people or livestock despite numerous autochthonous epizootic and human outbreaks of mosquito-borne diseases on the European mainland. Indeed, whether or not British mosquitoes are competent to transmit arboviruses has not been established. Therefore, the competence of a local (temperate) British mosquito species, Ochlerotatus detritus (=Aedes detritus) (Diptera: Culicidae) for transmission of a member of the genus Flavivirus, Japanese encephalitis virus (JEV) as a model for mosquito-borne virus transmission was assessed. The JEV competence in a laboratory strain of Culex quinquefasciatus (Diptera: Culicidae), a previously incriminated JEV vector, was also evaluated as a positive control. Ochlerotatus detritus adults were reared from field-collected juvenile stages. In oral infection bioassays, adult females developed disseminated infections and were able to transmit virus as determined by the isolation of virus in saliva secretions. When pooled at 7-21?days post-infection, 13% and 25% of O.?detritus were able to transmit JEV when held at 23?C and 28?C, respectively. Similar results were obtained for C.?quinquefasciatus. To our knowledge, this study is the first to demonstrate that a British mosquito species, O.?detritus, is a potential vector of an exotic flavivirus. PMID:25087926

Mackenzie-Impoinvil, L; Impoinvil, D E; Galbraith, S E; Dillon, R J; Ranson, H; Johnson, N; Fooks, A R; Solomon, T; Baylis, M

2015-03-01

110

A survey of mosquitoes breeding in used tires in Spain for the detection of imported potential vector species.  

PubMed

The used tire trade has facilitated the introduction, spread, and establishment of the Asian tiger mosquito, Aedes albopictus, and other mosquito species in several countries of America, Africa, Oceania, and Europe. A strategy for detecting these imported mosquito vectors was developed in Spain during 2003-2004 by EVITAR (multidisciplinary network for the study of viruses transmitted by arthropods and rodents). A survey in 45 locations found no invasive species. Eight autochthonous species of mosquitoes were detected in used tires, including Culex pipiens, Cx. hortensis, Cx. modestus, Anopheles atroparvus, An. claviger, Culiseta longiareolata, Cs. annulata, and Aedes caspius. Dominant species were Cx. pipiens and Cs. longiareolata. Aedes caspius was found in only once, near its natural breeding habitat. Considering the recent discovery of an established population of Ae. albopictus in Catalonia, the increasing commerce of used tires in Spain for recycling, storage, and recapping might greatly contribute to the rapid spread of this species across the Iberian Peninsula. PMID:17633420

Roiz, D; Eritja, R; Escosa, R; Lucientes, J; Marqus, E; Melero-Alcbar, R; Ruiz, S; Molina, R

2007-06-01

111

Bird-baited traps for surveillance of West Nile mosquito vectors: effect of bird species, trap height, and mosquito escape rates.  

PubMed

Host-seeking mosquitoes were sampled in bird-baited traps at four sites in New York state in 2003-2004. Trap placement and efficacy of chickens, Gallus gallus domesticus L., as bait compared with house sparrows, Passer domesticus L., an important reservoir of West Nile virus (family Flaviviridae, genus Flavivirus, WNV), was evaluated. Each site had a chicken-baited trap near ground level (approximately 1.5 m) and in the tree canopy (approximately 9 m), and a house sparrow-baited trap at ground level and canopy level. Each trap allowed mosquito access to birds on one end, and an inner mesh screen blocked bird access on the other end. The two most abundant mosquitoes, Culex restuans Theobald and Culex pipiens pipiens L., were differentiated using molecular characters. In 2003, Cx. restuans and Cx. p. pipiens made up 88% of total mosquito catch. In 2004, Cx. restuans comprised 43% of total catch and Cx. p. pipiens comprised 33%. The remaining species representing at least 1% of total catch were Ochlerotatus trivittatus (Coquillett), Coquilletidia perturbans (Walker), and Culiseta morsitans (Theobald). Capture rates were similar for chicken and house sparrow-baited traps; however, significantly more mosquitoes were captured in the canopy for both bird species. Cx. restuans preferred canopy traps, whereas equal numbers of Cx. p. pipiens were captured at ground and canopy levels. Mosquitoes were more likely to escape (74%) when excluded from birds than when allowed free access to birds (54%). Sentinel bird surveillance for WNV can be improved by trapping in the tree canopy in addition to ground level to capture the most important avian vectors. PMID:16506452

Darbro, Jonathan M; Harrington, Laura C

2006-01-01

112

Larval occurrence, oviposition behavior and biting activity of potential mosquito vectors of dengue on Samui Island, Thailand.  

PubMed

A 1995 outbreak of dengue haemorrhagic fever (DHF) occurred on Samui Island in Thailand with an incidence of almost 500 cases/100,000 population. To find and develop effective strategies to control this disease through cost-effective vector control programs, entomological studies were carried out on the island between 1996 and 1998. There were two species of DHF vectors, Aedes aegypti and Ae. albopictus prevailing on the island, and the population of Ae. aegypti remained relatively constant throughout the year while the abundance of Ae. albopictus increased substantially during the rainy season (May-December) and then declined drastically in the dry season (January-April). The ranges of the three Aedes larval indices, Breteau index (BI), house index (HI) and container index (CI) were 93-310, 43-89 and 16-50 respectively. The ceramic or earthen jars both inside and outside the dwellings and concrete water storage tanks (mostly in toilets and bathrooms) served as the main breeding places of Ae. aegypti whereas coconut husks and coconut floral spathes found outdoors were the major breeding sites of Ae. albopictus. The number of washing water jars, concrete tanks and natural sites infested with Aedes larvae increased significantly in rainy season, with 60% of ovitraps become positive for Ae. albopictus eggs with an average number of 26 eggs/trap in 3 days of setting. There was a complete lack of oviposition by Ae. aegypti in outdoor ovitraps (15 m away from the houses). The indoor biting rate ranged from 1.5 to 8.1 mosquitoes/man-hour, while the outdoor rate was between 5 and 78 mosquitoes/man-hour. Of the indoor biting mosquitoes, 75.4% were identified as Ae. aegypti and 99% of the outdoor ones were Ae. albopictus. The diel biting activity of Aedes during the period from 0800 h to 1700 h in the houses was higher in the morning than in the afternoon period, with a low prevalence between 1300 h and 1400 h. PMID:11813654

Thavara, U; Tawatsin, A; Chansang, C; Kong-ngamsuk, W; Paosriwong, S; Boon-Long, J; Rongsriyam, Y; Komalamisra, N

2001-12-01

113

Mosquitoes and the Diseases they Transmit  

E-print Network

) dorsalis are the main mosquito vectors for western equine encephalitis virus, particularly west of the Mississippi River. Other insects, such as the swallow bug (Cimicidae), may also serve as overwintering hosts of the WEE virus. SLE virus: Members...

Jackman, John A.; Olson, Jimmy K.

2002-06-21

114

Monitoring the aquatic toxicity of mosquito vector control spray pesticides to freshwater receiving waters.  

PubMed

Pesticides are applied to state and local waterways in California to control insects such as mosquitoes, which are known to serve as a vector for West Nile Virus infection of humans. The California State Water Resources Control Board adopted a National Pollutant Discharge Elimination System General Permit to address the discharge to waters of the United States of pesticides resulting from adult and larval mosquito control. Because pesticides used in spray activities have the potential to cause toxicity to nontarget organisms in receiving waters, the current study was designed to determine whether toxicity testing provides additional, useful environmental risk information beyond chemical analysis in monitoring spray pesticide applications. Monitoring included a combination of aquatic toxicity tests and chemical analyses of receiving waters from agricultural, urban, and wetland habitats. The active ingredients monitored included the organophosphate pesticides malathion and naled, the pyrethroid pesticides etofenprox, permethrin, and sumithrin, pyrethrins, and piperonyl butoxide (PBO). Approximately 15% of the postapplication water samples were significantly toxic. Toxicity of half of these samples was attributed to the naled breakdown product dichlorvos. Toxicity of 2 other water samples likely occurred when PBO synergized the effects of pyrethroid pesticides that were likely present in the receiving system. Four of 43 postapplication sediment samples were significantly more toxic than their corresponding pre-application samples, but none of the observed toxicity was attributed to the application events. These results indicate that many of the spray pesticides used for adult mosquito control do not pose significant acute toxicity risk to invertebrates in receiving systems. In the case of naled in water, analysis of only the active ingredient underestimated potential impacts to the receiving system, because toxicity was attributed to the breakdown product, dichlorvos. Toxicity testing can provide useful risk information about unidentified, unmeasured toxicants or mixtures of toxicants. In this case, toxicity testing provided information that could lead to the inclusion of dichlorvos monitoring as a permit requirement. PMID:24659580

Phillips, Bryn M; Anderson, Brian S; Voorhees, Jennifer P; Siegler, Katie; Denton, Debra; TenBrook, Patti; Larsen, Karen; Isorena, Philip; Tjeerdema, Ron S

2014-07-01

115

piRNA pathway gene expression in the malaria vector mosquito Anopheles stephensi  

PubMed Central

The ability of transposons to mobilize to new places in a genome enables them to introgress rapidly into populations. The piRNA pathway has been characterized recently in the germ line of the fruit fly, Drosophila melanogaster, and is responsible for downregulating transposon mobility. Transposons have been used as tools in mosquitoes to genetically transform a number of species including Anopheles stephensi, a vector of human malaria. These mobile genetic elements also have been proposed as tools to drive antipathogen effector genes into wild mosquito populations to replace pathogen-susceptible insects with those engineered genetically to be resistant to or unable to transmit a pathogen. The piRNA pathway may affect the performance of such proposed genetic engineering strategies. In the present study, we identify and describe the An. stephensi orthologues of the major genes in the piRNA pathway, Ago3, Aubergine (Aub) and Piwi. Consistent with a role in protection from transposon movement, these three genes are expressed constitutively in the germ-line cells of ovaries and induced further after a blood meal. PMID:24947897

Macias, V; Coleman, J; Bonizzoni, M; James, A A

2014-01-01

116

Vector ability of mosquitoes for isolates of Plasmodium elongatum from raptors in Florida.  

PubMed

Three isolates of Plasmodium elongatum were obtained from 3 species of raptors (red-tailed hawk [Buteo jamaicensis], bald eagle [Haliaeetus leucocephalus], and eastern screech owl [Otus asio]) from Florida using isodiagnostic techniques in Pekin ducks (Anas platyrhynchos). Six to 10 species of mosquitoes were tested for susceptibility to these 3 isolates. Complete development of the sporogonic cycle of the 3 isolates of P. elongatum occurred in 3 species of mosquitoes, Culex nigripalpus, Culex restuans, and Culex salinarius. The pattern of susceptibility was similar among the 3 isolates of P. elongatum in Cx. nigripalpus. Culex restuans and Cx. salinarius were significantly more susceptible than Cx. nigripalpus to the 3 isolates of P. elongatum tested. Culex nigripalpus transmitted all 3 isolates of P. elongatum from duck to duck both by bite and after intraperitoneal injection of sporozoites. Infections of the 2 isolates tested occurred in ducks after intraperitoneal injection of sporozoites from Cx. restuans and Cx. salinarius. The results suggest that these 3 Culex species are potential vectors of P. elongatum from raptors in Florida. PMID:9645854

Nayar, J K; Knight, J W; Telford, S R

1998-06-01

117

Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania  

PubMed Central

Background Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania. PMID:25613346

Mweya, Clement N.; Kimera, Sharadhuli I.; Mellau, Lesakit S. B.; Mboera, Leonard E. G.

2015-01-01

118

Bicluster pattern of codon context usages between flavivirus and vector mosquito Aedes aegypti: relevance to infection and transcriptional response of mosquito genes.  

PubMed

The mosquito Aedes aegypti is the primary vector of dengue virus (DENV) infection in most of the subtropical and tropical countries. Besides DENV, yellow fever virus (YFV) is also transmitted by A. aegypti. Susceptibility of A. aegypti to West Nile virus (WNV) has also been confirmed. Although studies have indicated correlation of codon bias between flaviviridae and their animal/insect hosts, it is not clear if codon sequences have any relation to susceptibility of A. aegypti to DENV, YFV and WNV. In the current study, usages of codon context sequences (codon pairs for neighboring amino acids) of the vector (A. aegypti) genome as well as the flaviviral genomes are investigated. We used bioinformatics methods to quantify codon context bias in a genome-wide manner of A. aegypti as well as DENV, WNV and YFV sequences. Mutual information statistics was applied to perform bicluster analysis of codon context bias between vector and flaviviral sequences. Functional relevance of the bicluster pattern was inferred from published microarray data. Our study shows that codon context bias of DENV, WNV and YFV sequences varies in a bicluster manner with that of specific sets of genes of A. aegypti. Many of these mosquito genes are known to be differentially expressed in response to flaviviral infection suggesting that codon context sequences of A. aegypti and the flaviviruses may play a role in the susceptible interaction between flaviviruses and this mosquito. The bias in usages of codon context sequences likely has a functional association with susceptibility of A. aegypti to flaviviral infection. The results from this study will allow us to conduct hypothesis-driven tests to examine the role of codon context bias in evolution of vector-virus interactions at the molecular level. PMID:24838953

Behura, Susanta K; Severson, David W

2014-10-01

119

Insecticide resistance in malaria vector mosquitoes at four localities in Ghana, West Africa  

PubMed Central

Background Malaria vector control programmes that rely on insecticide-based interventions such as indoor house spraying with residual insecticides or insecticide treated bed nets, need to base their decision-making process on sound baseline data. More and more commercial entities in Africa, such as mining companies, are realising the value to staff productivity of controlling malaria transmission in their areas of operation. This paper presents baseline entomological data obtained during surveys conducted for four mining operations in Ghana, West Africa. Results The vast majority of the samples were identified as Anopheles gambiae S form with only a few M form specimens being identified from Tarkwa. Plasmodium falciparum infection rates ranged from 4.5 to 8.6% in An. gambiae and 1.81 to 8.06% in An. funestus. High survival rates on standard WHO bioassay tests were recorded for all insecticide classes except the organophosphates that showed reasonable mortality at all locations (i.e. > 90%). The West African kdr mutation was detected and showed high frequencies in all populations. Conclusions The data highlight the complexity of the situation prevailing in southern Ghana and the challenges facing the malaria vector control programmes in this region. Vector control programmes in Ghana need to carefully consider the resistance profiles of the local mosquito populations in order to base their resistance management strategies on sound scientific data. PMID:21679391

2011-01-01

120

Evaluation of Hexane Extract of Tuber of Root of Cyperus rotundus Linn (Cyperaceae) for Repellency against Mosquito Vectors  

PubMed Central

Hexane extract of tuber of plant Cyperus rotundus (Cyperaceae) was screened under laboratory conditions for repellent activity against mosquito vector Anopheles culicifacies Giles species A (Diptera: Culicidae), Anopheles stephensi Liston (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae). The Cyperus rotundus tuber extract was used to determine their effect on mosquito vector, and comparison with the DEET (NN Diethyl 1-3 methyl Benzamide, formerly known as diethyl 1-m-toluamide). The tuber extracts showed more effective at all the dose. Result obtained from the laboratory experiment showed that the tuber extracts are more effective for repellency of allthe mosquito vector even at low dose. Clear dose response relationships were established with the highest dose of 10% tuber extract evoking 100% repellency. Percent protection obtained against An. culicifacies Giles species A 100% repellency in 4 hours, 6 hours, An. stephensi 100% repellency in 6 hours and Cx. quinquefasciatus was 100% repellency in 6 hours at the 10% concentration. Against DEET- 2.5% An. culicifacies A 100% repellency in 1 hour, 2 hours, 6 hours, An. stephensi have shown 100% repellency in 6 hours, and Culex quinquefasciatus have shown 100% repellency in 1 hour, 2 hours, 6 hours. The consolidated data of the repellency observed in different species is given and it is evident that the over all repellency rates varied between 80 and 100% for different repellents concentrations (2.5%, 5%, and 10%). The extract can be applied as an effective personal protective measure against mosquito bites. PMID:20798887

Singh, S. P.; Raghavendra, K.; Dash, A. P.

2009-01-01

121

Comparative Genome Analysis of the Yellow Fever Mosquito Aedes aegypti with Drosophila melanogaster and the Malaria Vector Mosquito Anopheles gambiae  

Microsoft Academic Search

An in silico comparative genomics approach was used to identify putative orthologs to genetically mapped genes from the mosquito, Aedes aegypti, in the Drosophila melanogaster and Anopheles gambiae genome databases. Comparative chromosome positions of 73 D. melanogaster orthologs indicated significant deviations from a random distribution across each of the five A. aegypti chromosomal regions, suggesting that some ancestral chromosome elements

D. W. Severson; B. DEBRUYN; D. D. LOVIN; S. E. BROWN; D. L. KNUDSON; I. MORLAIS

2004-01-01

122

Distribution and habitat characterization of the recently introduced invasive mosquito Aedes koreicus [Hulecoeteomyia koreica], a new potential vector and pest in north-eastern Italy  

PubMed Central

Background The container breeding species belonging to the genus Aedes (Meigen) are frequently recorded out of their place of origin. Invasive Aedes species are proven or potential vectors of important Arboviruses and their establishment in new areas pose a threat for human and animal health. A new species of exotic mosquito was recorded in 2011 in north-eastern Italy: Aedes (Finlaya) koreicus [Hulecoeteomyia koreica]. The aim of this study was to characterize the biology, the environment and the current distribution of this mosquito in north-eastern Italy. Morphological details useful to discriminate this species from other invasive Aedes mosquitoes are also given (see Additional files). Methods All possible breeding sites for larval development were monitored. In addition, ovitraps and traps for adults were used to collect eggs and adults. The mosquitoes (larvae and adults) were identified morphologically and molecularly. Environmental data and climatic variables during the period of mosquito activity (from April to October) were considered. Results Aedes koreicus was found in 37 municipalities (39.4%) and was detected in 40.2% of places and in 37.3% of larval habitats monitored, in a range of altitude from 173 to 1250m.a.s.l.. Garden centres were the most common locations (66.7%), followed by streets/squares (57.1%), private gardens (46.4%) and cemeteries (21.1%) (p?main larval habitats were catch basins (48.5%) and artificial water containers (41.8%). As for Aedes albopictus [Stegomyia albopicta], ovitraps were attractive for adult females resulting in the higher rate of positivity (15/21; 71.4%) among breeding sites. The period of Ae. koreicus activity ranged from March 29 to October 29. Conclusion The species is clearly established in the area and is now overlapping with other vectors such as Ae. albopictus and colonizing areas over 800m.a.s.l, not yet or sporadically reached by the tiger mosquito. The data collected are essential to assess the risk of colonization of other parts of Italy and Europe, as well as the risk of spreading of pathogens transmitted. These findings stress the importance of implementing entomological surveillance for early detection of invasive species, which is necessary for eradication or limitation of its further spread. PMID:24457085

2013-01-01

123

Systematics of mosquito disease vectors (Diptera, Culicidae): impact of molecular biology and cladistic analysis.  

PubMed

The field of medical entomology, by nature of its association with problems of human health, has been conservative in its application of molecular and computer technologies to systematic research. Recently, however, these methods have opened new interpretations for systematics of disease vectors. Medically important insects, particularly mosquitoes, are among those more thoroughly described by conventional taxonomy, and thereby provide a secure framework for testing congruencies with molecular data. In turn, molecular investigations have provided a stimulus to vector systematics in the discovery and delineation of cryptic species complexes, as well as providing new perspectives on relationships at higher taxonomic divisions. In this review, examples involving cladistic analysis, cytogenetics--in situ hybridization, isoenzymes, DNA sequencing, and restriction fragment polymorphism are drawn from the following taxa: Aedes communis; Aedes (Ochlerotatus) group G; Aedes (Stegomyia) species including A. aegypti, A. albopictus, and A. scutellaris group; Anopheles albitarsis, Anopheles dirus, Anopheles gambiae, Anopheles nuneztovari, Anopheles pseudopunctipennis, and Anopheles punctulatus groups; Culex pipiens and the Culex subgenus Melanoconion; and the tribe Sabethini. PMID:9017898

Munstermann, L E; Conn, J E

1997-01-01

124

Aromatic plant-derived essential oil: An alternative larvicide for mosquito control  

Microsoft Academic Search

Five aromatic plants, Carum carvi (caraway), Apium graveolens (celery), Foeniculum vulgare (fennel), Zanthoxylum limonella (mullilam) and Curcuma zedoaria (zedoary) were selected for investigating larvicidal potential against mosquito vectors. Two laboratory-reared mosquito species, Anopheles dirus, the major malaria vector in Thailand, and Aedes aegypti, the main vector of dengue and dengue hemorrhagic fever in urban areas, were used. All of the

B. Pitasawat; D. Champakaew; W. Choochote; A. Jitpakdi; U. Chaithong; D. Kanjanapothi; E. Rattanachanpichai; P. Tippawangkosol; D. Riyong; B. Tuetun; D. Chaiyasit

2007-01-01

125

Zooprophylaxis or zoopotentiation: the outcome of introducing animals on vector transmission is highly dependent on the mosquito mortality while searching  

PubMed Central

Background Zooprophylaxis, the diversion of disease carrying insects from humans to animals, may reduce transmission of diseases such as malaria. However, as the number of animals increases, improved availability of blood meals may increase mosquito survival, thereby countering the impact of diverting feeds. Methods Computer simulation was used to examine the effects of animals on the transmission of human diseases by mosquitoes. Three scenarios were modelled: (1) endemic transmission, where the animals cannot be infected, eg. malaria; (2) epidemic transmission, where the animals cannot be infected but humans remain susceptible, e.g. malaria; (3) epidemic disease, where both humans and animals can be infected, but develop sterile immunity, eg. Japanese encephalitis B. For each, the passive impact of animals as well as the use of animals as bait to attract mosquitoes to insecticide was examined. The computer programmes are available from the author. A teaching model accompanies this article. Results For endemic and epidemic malaria with significant searching-associated vector mortality, changing animal numbers and accessibility had little impact. Changing the accessibility of the humans had a much greater effect. For diseases with an animal amplification cycle, the most critical factor was the proximity of the animals to the mosquito breeding sites. Conclusion Estimates of searching-associated vector mortality are essential before the effects of changing animal husbandry practices can be predicted. With realistic values of searching-associated vector mortality rates, zooprophylaxis may be ineffective. However, use of animals as bait to attract mosquitoes to insecticide is predicted to be a promising strategy. PMID:14565850

Saul, Allan

2003-01-01

126

Adulticidal properties of synthesized silver nanoparticles using leaf extracts of Feronia elephantum (Rutaceae) against filariasis, malaria, and dengue vector mosquitoes.  

PubMed

Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternative sources of mosquito control agents because they constitute a rich source of bioactive compounds that are biodegradable into nontoxic products and potentially suitable for use to control mosquitoes. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Feronia elephantum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. The range of concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 ?g mL(-1)) and aqueous leaf extract (40, 80, 120, 160, and 200 ?g mL(-1)) were tested against the adults of A. stephensi, A. aegypti, and C. quinquefasciatus. Adults were exposed to varying concentrations of aqueous crude extract and synthesized AgNPs for 24 h. Considerable mortality was evident after the treatment of F. elephantum for all three important vector mosquitoes. The synthesized AgNPs from F. elephantum were highly toxic than crude leaf aqueous extract to three important vector mosquito species. The results were recorded from UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy analysis (EDX), and transmission electron microscopy (TEM). Synthesized AgNPs against the vector mosquitoes A. stephensi, A. aegypti, and C. quinquefasciatus had the following lethal dose (LD)?? and LD?? values: A. stephensi had LD?? and LD?? values of 18.041 and 32.575 ?g mL(-1); A. aegypti had LD?? and LD?? values of 20.399 and 37.534 ?g mL(-1); and C. quinquefasciatus had LD?? and LD?? values of 21.798 and 39.596 ?g mL(-1). No mortality was observed in the control. These results suggest that the leaf aqueous extracts of F. elephantum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of the A. stephensi, A. aegypti, and C. quinquefasciatus. This is the first report on the adulticidal activity of the plant extracts and AgNPs. PMID:25146645

Veerakumar, Kaliyan; Govindarajan, Marimuthu

2014-11-01

127

Geostatistical evaluation of integrated marsh management impact on mosquito vectors using before-after-control-impact (BACI) design  

PubMed Central

Background In many parts of the world, salt marshes play a key ecological role as the interface between the marine and the terrestrial environments. Salt marshes are also exceedingly important for public health as larval habitat for mosquitoes that are vectors of disease and significant biting pests. Although grid ditching and pesticides have been effective in salt marsh mosquito control, marsh degradation and other environmental considerations compel a different approach. Targeted habitat modification and biological control methods known as Open Marsh Water Management (OMWM) had been proposed as a viable alternative to marsh-wide physical alterations and chemical control. However, traditional larval sampling techniques may not adequately assess the impacts of marsh management on mosquito larvae. To assess the effectiveness of integrated OMWM and marsh restoration techniques for mosquito control, we analyzed the results of a 5-year OMWM/marsh restoration project to determine changes in mosquito larval production using GIS and geostatistical methods. Methods The following parameters were evaluated using "Before-After-Control-Impact" (BACI) design: frequency and geographic extent of larval production, intensity of larval production, changes in larval habitat, and number of larvicide applications. The analyses were performed using Moran's I, Getis-Ord, and Spatial Scan statistics on aggregated before and after data as well as data collected over time. This allowed comparison of control and treatment areas to identify changes attributable to the OMWM/marsh restoration modifications. Results The frequency of finding mosquito larvae in the treatment areas was reduced by 70% resulting in a loss of spatial larval clusters compared to those found in the control areas. This effect was observed directly following OMWM treatment and remained significant throughout the study period. The greatly reduced frequency of finding larvae in the treatment areas led to a significant decrease (~44%) in the number of times when the larviciding threshold was reached. This reduction, in turn, resulted in a significant decrease (~74%) in the number of larvicide applications in the treatment areas post-project. The remaining larval habitat in the treatment areas had a different geographic distribution and was largely confined to the restored marsh surface (i.e. filled-in mosquito ditches); however only ~21% of the restored marsh surface supported mosquito production. Conclusion The geostatistical analysis showed that OMWM demonstrated considerable potential for effective mosquito control and compatibility with other natural resource management goals such as restoration, wildlife habitat enhancement, and invasive species abatement. GPS and GIS tools are invaluable for large scale project design, data collection, and data analysis, with geostatistical methods serving as an alternative or a supplement to the conventional inference statistics in evaluating the project outcome. PMID:19549297

Rochlin, Ilia; Iwanejko, Tom; Dempsey, Mary E; Ninivaggi, Dominick V

2009-01-01

128

Mosquitoes (Diptera: Culicidae) in New Zealand: reverting to the traditional Aedes nomenclature  

Microsoft Academic Search

Mosquito-borne diseases are one of the main causes of death and morbidity among humans worldwide. Globalisation is facilitating the spread of mosquitoes to new areas, and vigilance at international borders combined with ongoing surveillance are paramount to prevent the spread of mosquito vectors. This must be underpinned by prompt identification of species, and international consensus on the application of nomenclature

Jos G. B. Derraik

2007-01-01

129

First report in italy of the exotic mosquito species Aedes (Finlaya) koreicus, a potential vector of arboviruses and filariae  

PubMed Central

Background In the Veneto region (north-eastern Italy) an entomological surveillance system has been implemented since the introduction of the Asian tiger mosquito (Aedes albopictus) in 1991. During the routine monitoring activity in a tiger mosquito-free area, an unexpected mosquito was noticed, which clearly did not belong to the recorded Italian fauna. Findings At the end of May 2011, twelve larvae and pupae were collected in a small village in Belluno province (Veneto region) from a single manhole. Ten adults reared in the laboratory were morphologically and genetically identified as Aedes (Finlaya) koreicus (Edwards, 1917), a species native to Southeast Asia. The subsequent investigations carried out in the following months in the same village provided evidence that this species had become established locally. Entomological and epidemiological investigations are currently ongoing in the surrounding area, to verify the eventual extension of the species outside the village and to trace back the route of entry into Italy. Conclusions This is the first report in Italy of the introduction of the exotic mosquito Ae. koreicus. This species has been shown experimentally to be competent in the transmission of the Japanese encephalitis virus and of the dog heartworm Dirofilaria immitis and is considered a potential vector of other arboviruses. Thus, the establishment of this species may increase the current risk or pose new potential threats, for human and animal health. This finding considerably complicates the entomological monitoring of the Asian tiger mosquito Ae. albopictus in Italy and stresses the importance of implementing the entomological surveillance for the early detection of and the rapid response against invasive mosquito species. PMID:21951867

2011-01-01

130

Mosquito Life Cycle  

NSDL National Science Digital Library

In this activity, learners build a plastic emergence chamber (or use purchased "mini mosquito breeder") to observe and analyze the mosquito life cycle. Learners record daily observations for 8-14 days by counting the number of larvae, pupae, and adults present in the chamber. This resource includes background information about the mosquito life cycle and mosquitoes as disease vectors plus a link to a mosquito reference manual.

Howard Hughes Medical Institute

2010-01-01

131

Mosquito larvicidal activities of Solanum villosum berry extract against the dengue vector Stegomyia aegypti  

PubMed Central

Background Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. Although several plants have been reported for mosquitocidal activity, only a few botanicals have moved from the laboratory to field use, because they are poorly characterized, in most cases active principals are not determined and most of the works are restricted to preliminary screening. Solanum villosum is a common weed distributed in many parts of India with medicinal properties, but the larvicidal activity of this plant has not been reported so far. Methods Aqueous and polar/non-polar solvent extract of fresh, mature, green berries of S. villosum was tested against Stegomyia aegypti, a common vector of dengue fever. A phytochemical analysis of chloroform:methanol extract was performed to search for the active toxic ingredient. The lethal concentration was determined (log probit analysis) and compared with Malathion. The chemical nature of the active substance was also evaluated following ultraviolet-visual (UV-Vis) and infrared (IR) analysis. Results In a 72 hour bioassay experiment with the aqueous extract, the highest mortality was recorded in 0.5% extract. When the mortality of different solvent extracts was compared, the maximum (p < 0.05) mortality was recorded at a concentration of 50 ppm of chloroform:methanol extract (1:1, v/v). The larvicidal activity was lower when compared with the chemical insecticide, Malathion (p < 0.05). Results of regression analysis revealed that the mortality rate (Y) was positively correlated with the period of exposure (X) and the log probit analysis (95% confidence level) recorded lowest value (5.97 ppm) at 72 hours of exposure. Phytochemical analysis of the chlororm:methanol extract reported the presence of many bioactive phytochemicals. Two toxic compounds were detected having Rf = 0.82 (70% and 73.33% mortality in 24 and 48 hours, respectively) and Rf = 0.95 (40% and 50% mortality in 24 and 48 hours, respectively). IR analysis provided preliminary information about the steroidal nature of the active ingredient. Conclusion S. villosum offers promise as potential bio control agent against S. aegypti particularly in its markedly larvicidal effect. The extract or isolated bioactive phytochemical could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases. PMID:18387176

Chowdhury, Nandita; Ghosh, Anupam; Chandra, Goutam

2008-01-01

132

Requirement of Glycosylation of West Nile Virus Envelope Protein for Infection of, but Not Spread within, Culex quinquefasciatus Mosquito Vectors  

PubMed Central

Most of sequenced West Nile virus (WNV) genomes encode a single N-linked glycosylation site on their envelope (E) proteins. We previously found that WNV lacking the E protein glycan was severely inhibited in its ability to replicate and spread within two important mosquito vector species, Culex pipiens and Cx. tarsalis. However, recent work with a closely related species, Cx. pipiens pallens, found no association between E protein glycosylation and either replication or dissemination. To examine this finding further, we expanded upon our previous studies to include an additional Culex species, Cx. quinquefasciatus. The non-glycosylated WNV-N154I virus replicated less efficiently in mosquito tissues after intrathoracic inoculation, but there was little difference in replication efficiency in the midgut after peroral infection. Interestingly, although infectivity was inhibited when WNV lacked the E protein glycan, there was little difference in viral spread throughout the mosquito. These data indicate that E protein glycosylation affects WNVvector interactions in a species-specific manner. PMID:21813861

Moudy, Robin M.; Payne, Anne F.; Dodson, Brittany L.; Kramer, Laura D.

2011-01-01

133

The fog of war: why the environmental crusade for anadromous fish species in California could disarm the state's local vector control districts in their war against mosquitoes.  

PubMed

In California, local mosquito and vector control districts have successfully controlled mosquito and vector-borne diseases by improving drainage patterns and applying pesticides. The Bay-Delta Conservation Plan, which is a proposed habitat conservation plan for the Sacramento-San Joaquin Bay-Delta estuary, proposes to add over 70,000 acres of habitat in the Delta to improve conditions for threatened and endangered aquatic and terrestrial species. This habitat could also be a suitable mosquito breeding habitat, which will be located in close proximity to urban and suburban communities. Wetland management practices and continued pesticide applications in the Delta could mitigate the effects of a new mosquito breeding habitat. Recent legal developments, however, require districts to obtain and comply with Clean Water Act permits, which restrict the application of pesticides in or near waters of the United States. Moreover, the U.S. Environmental Protection Agency has taken the first step in a rulemaking process that could further limit or prohibit the use of certain vector control pesticides in the Delta. In the near term and until less harmful methods for mosquito control are available, local vector control districts' application of mosquito control pesticides should be exempt from Clean Water Act permit requirements. PMID:23856372

Siptroth, Stephen M; Shanahan, Richard P

2011-12-01

134

Chromobacterium Csp_P Reduces Malaria and Dengue Infection in Vector Mosquitoes and Has Entomopathogenic and In Vitro Anti-pathogen Activities  

PubMed Central

Plasmodium and dengue virus, the causative agents of the two most devastating vector-borne diseases, malaria and dengue, are transmitted by the two most important mosquito vectors, Anopheles gambiae and Aedes aegypti, respectively. Insect-bacteria associations have been shown to influence vector competence for human pathogens through multi-faceted actions that include the elicitation of the insect immune system, pathogen sequestration by microbes, and bacteria-produced anti-pathogenic factors. These influences make the mosquito microbiota highly interesting from a disease control perspective. Here we present a bacterium of the genus Chromobacterium (Csp_P), which was isolated from the midgut of field-caught Aedes aegypti. Csp_P can effectively colonize the mosquito midgut when introduced through an artificial nectar meal, and it also inhibits the growth of other members of the midgut microbiota. Csp_P colonization of the midgut tissue activates mosquito immune responses, and Csp_P exposure dramatically reduces the survival of both the larval and adult stages. Ingestion of Csp_P by the mosquito significantly reduces its susceptibility to Plasmodium falciparum and dengue virus infection, thereby compromising the mosquito's vector competence. This bacterium also exerts in vitro anti-Plasmodium and anti-dengue activities, which appear to be mediated through Csp_P -produced stable bioactive factors with transmission-blocking and therapeutic potential. The anti-pathogen and entomopathogenic properties of Csp_P render it a potential candidate for the development of malaria and dengue control strategies. PMID:25340821

Bahia, Ana C.; Saraiva, Raul G.; Dong, Yuemei; Kang, Seokyoung; Tripathi, Abhai; Mlambo, Godfree; Dimopoulos, George

2014-01-01

135

Comparison of the vector potential of different mosquito species for the transmission of heartworm, Dirofilaria immitis, in rural and urban areas in and surrounding Stillwater, Oklahoma, U.S.A.  

PubMed

Dirofilaria immitis Leidy (Spirurida: Onchocercidae), or heartworm, is a mosquito-borne nematode that causes a fatal disease in carnivores. Although infection is preventable through prophylactic drugs, compliance and the spectre of resistance suggest vector control is a viable alternative. There were two main objectives in this study: (a) to evaluate the relationships between landscape and social factors and the number and species of heartworm-positive mosquitoes, with a specific focus on the importance of the invasive Asian tiger mosquito, Aedes albopictus (Skuse) (Stegomyia albopicta) (Diptera: Culicidae), and (b) to test the hypothesis that dog heartworm is more prevalent in suburban than in rural areas. To achieve these objectives, mosquitoes were collected from May to November 2010 at 16 rural and 16 urban locations in Payne County, Oklahoma, U.S.A. using three trapping methods that utilized, respectively, resting boxes, carbon dioxide traps and BG Sentinel traps. Urban areas showed greater numbers of Ae.?albopictus and a higher overall likelihood of infection with D.?immitis. Because many species of mosquito are responsible for heartworm transmission, current prophylactic treatment remains the best method of controlling this parasite. PMID:24898348

Paras, K L; O'Brien, V A; Reiskind, M H

2014-08-01

136

Field Detection of Tembusu Virus in Western Thailand by RT-PCR and Vector Competence Determination of Select Culex Mosquitoes for Transmission of the Virus  

PubMed Central

Tembusu virus (TMUV; Ntaya serocomplex) was detected in two pools of mosquitoes captured near Sangkhlaburi, Thailand, as well as from sera from sentinel ducks from the same area. Although TMUV has been isolated from several mosquito species in Asia, no studies have ever shown competent vectors for this virus. Therefore, we allowed mosquitoes captured near Sangkhlaburi to feed on young chickens that had been infected with TMUV. These mosquitoes were tested approximately 2 weeks later to determine infection, dissemination, and transmission rates. Culex vishnui developed high viral titers after feeding on TMUV-infected chicks and readily transmitted virus to nave chickens. In contrast, Cx. fuscocephala seemed less susceptible to infection, and more importantly, zero of five fuscocephala with a disseminated infection transmitted virus by bite, indicating a salivary gland barrier. These results provide evidence for the involvement of Culex mosquitoes in the transmission of TMUV in the environment. PMID:24043687

O'Guinn, Monica L.; Turell, Michael J.; Kengluecha, Ampornpan; Jaichapor, Boonsong; Kankaew, Prasan; Miller, R. Scott; Endy, Timothy P.; Jones, James W.; Coleman, Russell E.; Lee, John S.

2013-01-01

137

Pupicidal and repellent activities of Pogostemon cablin essential oil chemical compounds against medically important human vector mosquitoes  

PubMed Central

Objective To determine the repellent and pupicidal activities of Pogostemon cablin (P. cablin) chemical compositions were assayed for their toxicity against selected important vector mosquitoes, viz., Aedes aegypti (Ae. aegypti), Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus) (Diptera: Culicidae). Methods The plants dry aerial parts were subjected to hydrodistillation using a modified Clevenger-type apparatus. The composition of the essential oil was analyzed by Gas Chromatography (GC) and GC mass spectrophotometry. Evaluation was carried out in a net cage (45 cm30 cm45 cm) containing 100 blood starved female mosquitoes and were assayed in the laboratory condition by using the protocol of WHO 2010. The repellent activity of P. cablin chemical compositions at concentration of 2mg/cm2were applied on skin of fore arm in man and exposed against adult female mosquitoes. The pupicidal activity was determined against selected important vector mosquitoes to concentration of 100 mg/L and mortality of each pupa was recorded after 24 h of exposure to the compounds. Results Chemical constituents of 15 compounds were identified in the oil of P.cablin compounds representing to 98.96%. The major components in essential oil were -patchoulene, -guaiene, -patchoulene, -bulnesene and patchouli alcohol. The repellent activity of patchouli alcohol compound was found to be most effective for repellent activity and 2 mg/cm2 concentration provided 100% protection up to 280 min against Ae. aegypti, An. stephensi and Cx. quinquefasciatus, respectively. Similarly, pupae exposed to 100 mg/L concentrations of P. cablin chemical compositions. Among five compounds tested patchouli alcoholwas found to be most effective for pupicidal activity provided 28.44, 26.28 and 25.36 against Ae.aegypti, An.stephensi and Cx. quinquefasciatus, respectively. The percent adult emergence was inversely proportional to the concentration of compounds and directly proportional to the pupal mortality. Conclusion These results suggest that the P. cablin chemical compositions have the potential to be used as an ideal eco-friendly approach for the control of mosquitoes. This is the first report on the mosquito repellent and pupicidal activities of the reported P. cablin chemical compositions.

Gokulakrishnan, J; Kuppusamy, Elumalai; Shanmugam, Dhanasekaran; Appavu, Anandan; Kaliyamoorthi, Krishnappa

2013-01-01

138

Larvicidal efficacy of different plant parts of railway creeper, Ipomoea cairica Extract Against Dengue Vector Mosquitoes, Aedes albopictus (Diptera: Culicidae) and Aedes aegypti (Diptera: Culicidae).  

PubMed

Natural insecticides from plant origin against mosquito vectors have been the main concern for research due to their high level of eco-safety. Control of mosquitoes in their larval stages are an ideal method since Aedes larvae are aquatic, thus it is easier to deal with them in this habitat. The present study was specifically conducted to explore the larvicidal efficacy of different plant parts of Ipomoea cairica (L.) or railway creeper crude extract obtained using two different solvents; methanol and acetone against late third-stage larvae of Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae). Plant materials of I. cairica leaf, flower, and stem were segregated, airdried, powdered, and extracted using Soxhlet apparatus. Larvicidal bioassays were performed by using World Health Organization standard larval susceptibility test method for each species which were conducted separately for different concentration ranging from 10 to 450 ppm. Both acetone and methanol extracts showed 100% mortality at highest concentration tested (450 ppm) after 24 h of exposure. Results from factorial ANOVA indicated that there were significant differences in larvicidal effects between mosquito species, solvent used and plant parts (F=5.71, df=2, P<0.05). The acetone extract of I. cairica leaf showed the most effective larvicidal action in Ae. aegypti with LC50 of 101.94 ppm followed by Ae. albopictus with LC50 of 105.59 ppm compared with other fractions of I. cairica extract obtained from flower, stem, and when methanol are used as solvent. The larvae of Ae. aegypti appeared to be more susceptible to I. cairica extract with lower LC50 value compared with Ae. albopictus (F=8.83, df=1, P<0.05). Therefore, this study suggests that the acetone extract of I. cairica leaf can be considered as plant-derived insecticide for the control of Aedes mosquitoes. This study quantified the larvicidal property of I. cairica extract, providing information on lethal concentration that may have potential for a more eco-friendly Aedes mosquito control program. PMID:25368088

AhbiRami, Rattanam; Zuharah, Wan Fatma; Thiagaletchumi, Maniam; Subramaniam, Sreeramanan; Sundarasekar, Jeevandran

2014-01-01

139

An update on the incidence of dengue gaining strength in Saudi Arabia and current control approaches for its vector mosquito  

PubMed Central

Background The cases of dengue reported earlier in the late 1990s from the Kingdom of Saudi Arabia (KSA) occurred in the cities of Jeddah and Makkah. Although the kingdom has ample financial resources to establish effective control measures for the dengue vector, numerous cases of dengue occur and fluctuate in numbers from year to year. This necessitates a serious review of the current vector control strategies being practiced in order to identify the existing shortcomings. This short report provides an update on epidemiology of dengue in KSA (specifically in cities of Jeddah and Makkah) with a critical look at the current vector control strategies. Findings In 2013, 4411 cases of dengue were reported, with 8 cases of mortality. This number of dengue incidence was four times higher compared to 2012. In 2013, the highest number of 1272 dengue cases was reported in May, while the lowest number (37) of cases was reported in September. Conclusions It is evident that the control strategies of the dengue vector presently employed are inadequate. There seems to be serious deficiencies in following proper scientific procedures during field application(s) of control materials against the vector as is evident by the increases in the number of dengue cases as well as frequent outbreaks of the vector mosquito populations. In this review, some specific suggestions are made to draw attention to the relevant KSA authorities of the possible reasons behind unsuccessful control results and as to how to improve the strategy of dengue vector control in the kingdom. PMID:24890567

2014-01-01

140

Daily and seasonal variation in the activity of potential vector mosquitoes  

Microsoft Academic Search

In the course of season 2010 (MaySeptember), three 2-day trappings of female mosquitoes were carried out at two sites in\\u000a order to determine the daily activity of the common mosquito species (e.g. species from genus Culex, Aedes, Ochlerotatus, Anopheles, etc.) in the area. CDC light traps filled with CO2 and placed at a height of 1 m were used to

Old?ich ebesta; Ivan Gelbi?; Juraj Peko

2011-01-01

141

A system for studying vector competence of mosquitoes for Japanese encephalitis virus.  

PubMed

A method to infect mosquitoes with Japanese encephalitis virus (JEV) and to demonstrate virus transmission after an extrinsic incubation period is described. Using per oral feeding method infection rate as high as 90% could be achieved. Demonstration of transmission of the virus was achieved by allowing the infected mosquitoes to probe a suitable serum medium and testing the probed serum for virus. Both infection and transmission were demonstrated by using insect-bioassay. PMID:10497840

Samuel, P P; Hiriyan, J; Thenmozhi, V; Balasubramanian, A

1998-09-01

142

Potential mosquito vectors of arboviruses in Portugal: species, distribution, abundance and West Nile infection.  

PubMed

Circulation of West Nile virus in Portugal was demonstrated by serological surveys, and the virus was isolated in 1969 from Anopheles maculipennis s.l. A survey of the whole country was carried out (2001-2004) to assess the abundance of mosquito species and to screen them for arbovirus infection. A total of 770 collections yielded 32460 mosquitoes of 15 species. The regions with the highest abundance of mosquitoes were the coastal and estuarine districts of Santarm, Setbal and Faro. Culex pipiens s.l., An. maculipennis s.l., Cx. theileri and Ochlerotatus caspius were the most abundant and widespread, accounting for 92% of mosquitoes caught. Anopheles maculipennis s.l. and Cx. pipiens s.l. were present all over the country. Culex theileri and. Oc. caspius were more abundant in the southern and coastal areas, respectively. A total of 2355 mosquito pools were screened by RT-PCR for flaviviruses, of which 987 pools were also screened for bunyaviruses. Culex pipiens s.l. and Cx. univittatus collected in 2004 in the southern district of Faro were found to be infected with West Nile virus. The density and proximity of these mosquitoes to the human populations may constitute a public health threat in the case of involvement in arbovirus transmission cycles. PMID:18455742

Almeida, A P G; Galo, R P; Sousa, C A; Novo, M T; Parreira, R; Pinto, J; Piedade, J; Esteves, A

2008-08-01

143

West Nile virus transmission in sentinel chickens and potential mosquito vectors, Senegal River Delta, 2008-2009.  

PubMed

West Nile virus (WNV) is an arthropod-borne Flavivirus usually transmitted to wild birds by Culex mosquitoes. Humans and horses are susceptible to WNV but are dead-end hosts. WNV is endemic in Senegal, particularly in the Senegal River Delta. To assess transmission patterns and potential vectors, entomological and sentinel serological was done in Ross Bethio along the River Senegal. Three sentinel henhouses (also used as chicken-baited traps) were set at 100 m, 800 m, and 1,300 m from the river, the latter close to a horse-baited trap. Blood samples were taken from sentinel chickens at 2-week intervals. Seroconversions were observed in sentinel chickens in November and December. Overall, the serological incidence rate was 4.6% with 95% confidence interval (0.9; 8.4) in the sentinel chickens monitored for this study. Based on abundance pattern, Culex neavei was the most likely mosquito vector involved in WNV transmission to sentinel chickens, and a potential bridge vector between birds and mammals. PMID:24084679

Fall, Assane Gueye; Diat, Amadou; Seck, Momar Talla; Bouyer, Jrmy; Lefranois, Thierry; Vachiry, Nathalie; Aprelon, Rosalie; Faye, Ousmane; Konat, Lassana; Lancelot, Renaud

2013-10-01

144

vectors  

NSDL National Science Digital Library

The word vector comes from the Latin term vehere, to carry. In Biology, a vector is an agent which carries disease, such as a mosquito carrying infected blood from one patient to the next. In physics, a vector is a quantity which has both a magnitude and a direction associated with it. The most commonly used example of vectors in everyday life is velocity. When you drive your car, your speedometer tells you the speed of your car, but it doesn't tell you where you are going. The combination of both where you are going and how fast you are going there is your car's velocity.

David Joiner

145

PlasmodiumMosquito Interactions  

Microsoft Academic Search

Mosquitoes serve as the obligate vectors for the transmission of malaria parasites. During its sexual life cycle within the mosquito, the parasite must undergo several morphological changes and overcome developmental bottlenecks to ensure its successful transmission to a new vertebrate host. Here we review our current understanding of the molecular interactions that occur between Plasmodium parasites and its mosquito (Genus:

Ryan C. Smith; Marcelo Jacobs-Lorena

2010-01-01

146

The use of annual killifish in the biocontrol of the aquatic stages of mosquitoes in temporary bodies of fresh water; a potential new tool in vector control  

PubMed Central

Background Mosquitoes that breed in temporary pools in remote areas that dry up seasonally are especially difficult to control through chemical or biological means. The annual killifish has been suggested as a means of eradicating the aquatic stages of mosquitoes in transient pools because they can maintain permanent populations in such habitats by undergoing suspended animation or diapause during the embryonic stages to survive periodic drought. However, very little is known about the predatory activity of annual killifish and their usefulness in mosquito control. Results The annual killifish, Nothobranchius guentheri, native to Tanzania, was used in this investigation. Food preference was tested under laboratory conditions by feeding juvenile killifish with 2nd instar mosquito larvae of Culex quinquefasciatus in the presence of alternative food sources, such as rotifers and chironomid larvae. Semi-field tests were conducted by introduction of hibernating killifish embryos and juvenile fish to artificial ponds in an outdoor open environment that allowed natural oviposition of Cx. quinquefasciatus. Food preference studies show that N. guentheri preferred to prey on mosquito larvae than either chironomid or rotifers. When hibernating killifish embryos were added to ponds simultaneously with the addition of freshwater, the embryos hatched and fed on mosquito larval population resulting in complete elimination of the immature stages. The introduction of juvenile fish to ponds with high density of mosquito larvae resulted in total eradication of the mosquito population due to predation by fish. Complete biocontrol of the mosquito larval population was achieved in the presence of 3 fish per m2 of pond surface area. Conclusions The annual killifish provides yet another tool that may be employed in the eradication diseases carried by mosquitoes through vector control, particularly in temporary bodies of freshwater. The fish can be conveniently transported in the absence of water in the form of hibernating embryos. Once introduced either as embryos or juveniles in ponds, the annual killifish can effectively reduce the larval population because of its aggressive predatory activity. PMID:20492714

2010-01-01

147

Impact of climate and mosquito vector abundance on sylvatic arbovirus circulation dynamics in senegal.  

PubMed

Sylvatic arboviruses have been isolated in Senegal over the last 50 years. The ecological drivers of the pattern and frequency of virus infection in these species are largely unknown. We used time series analysis and Bayesian hierarchical count modeling on a long-term arbovirus dataset to test associations between mosquito abundance, weather variables, and the frequency of isolation of dengue, yellow fever, chikungunya, and Zika viruses. We found little correlation between mosquito abundance and viral isolations. Rainfall was a negative predictor of dengue virus (DENV) isolation but a positive predictor of Zika virus isolation. Temperature was a positive predictor of yellow fever virus (YFV) isolations but a negative predictor of DENV isolations. We found slight interference between viruses, with DENV negatively associated with concurrent YFV isolation and YFV negatively associated with concurrent isolation of chikungunya virus. These findings begin to characterize some of the ecological associations of sylvatic arboviruses with each other and climate and mosquito abundance. PMID:25404071

Althouse, Benjamin M; Hanley, Kathryn A; Diallo, Mawlouth; Sall, Amadou A; Ba, Yamar; Faye, Ousmane; Diallo, Diawo; Watts, Douglas M; Weaver, Scott C; Cummings, Derek A T

2015-01-01

148

Olfactory learning and memory in the disease vector mosquito Aedes aegypti.  

PubMed

Olfactory learning in blood-feeding insects, such as mosquitoes, could play an important role in host preference and disease transmission. However, standardised protocols allowing testing of their learning abilities are currently lacking, and how different olfactory stimuli are learned by these insects remains unknown. Using a Pavlovian conditioning paradigm, we trained individuals and groups of Aedes aegypti mosquitoes to associate an odorant conditioned stimulus (CS) with a blood-reinforced thermal stimulus (unconditioned stimulus; US). Results showed, first, that mosquitoes could learn the association between L-lactic acid and the US, and retained the association for at least 24 h. Second, the success of olfactory conditioning was dependent upon the CS--some odorants that elicited indifferent responses in nave mosquitoes, such as L-lactic acid and 1-octen-3-ol, were readily learned, whereas others went from aversive to attractive after training (Z-3-hexen-1-ol) or were untrainable (?-myrcene and benzyl alcohol). Third, we examined whether mosquitoes' ability to learn could interfere with the action of the insect repellent DEET. Results demonstrated that pre-exposure and the presence of DEET in the CS reduced the aversive effects of DEET. Last, the nature of the formed memories was explored. Experiments using cold-shock treatments within the first 6 h post-training (for testing anaesthesia-resistant memory) and a protein synthesis inhibitor (cycloheximide; to disrupt the formation of long-term memory) both affected mosquitoes' performances. Together, these results show that learning is a crucial component in odour responses in A. aegypti, and provide the first evidence for the functional role of different memory traces in these responses. PMID:24737761

Vinauger, Clment; Lutz, Eleanor K; Riffell, Jeffrey A

2014-07-01

149

Interspecific competition during transmission of two sympatric malaria parasite species to the mosquito vector.  

PubMed Central

The role of species interactions in structuring parasite communities remains controversial. Here, we show that interspecific competition between two avian malaria parasite species, Plasmodium gallinaceum and P. juxtanucleare, occurs as a result of interference during parasite fertilization within the bloodmeal of the mosquito. The significant reduction in the transmission success of P. gallinaceum to mosquitoes, due to the co-infecting P. juxtanucleare, is predicted to have compromised its colonization of regions occupied by P. juxtanucleare and, thus, may have contributed to the restricted global distribution of P. gallinaceum. Such interspecies interactions may occur between human malaria parasites and, thus, impact upon parasite species epidemiology, especially in regions of seasonal transmission. PMID:12573069

Paul, Rick E L; Nu, Van Anh Ton; Krettli, Antoniana U; Brey, Paul T

2002-01-01

150

Entomopathogenic fungi for mosquito control: A review  

PubMed Central

Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti) curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis. PMID:15861235

Scholte, Ernst-Jan; Knols, Bart G.J.; Samson, Robert A.; Takken, Willem

2004-01-01

151

Hey! A Mosquito Bit Me!  

MedlinePLUS

... Main Page The Pink Locker Society Hey! A Mosquito Bit Me! KidsHealth > Kids > Illnesses & Injuries > Bug Bites ... Do How to Avoid Getting Bitten What's a Mosquito? A mosquito (say: mus-KEE-toe) is an ...

152

Vector Competence of Selected African Mosquito (Diptera: Culicidae) Species for Rift Valley Fever Virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Outbreaks of Rift Valley fever (RVF) in Egypt, Yemen, and Saudi Arabia have indicated the potential for this disease to spread from its enzootic areas in sub-Saharan Africa. Because little is known about the potential for most African mosquito species to transmit RVF virus (RVFV), we conducted stud...

153

Made-to-measure malaria vector control strategies: rational design based on insecticide properties and coverage of blood resources for mosquitoes.  

PubMed

Eliminating malaria from highly endemic settings will require unprecedented levels of vector control. To suppress mosquito populations, vector control products targeting their blood hosts must attain high biological coverage of all available sources, rather than merely high demographic coverage of a targeted resource subset, such as humans while asleep indoors. Beyond defining biological coverage in a measurable way, the proportion of blood meals obtained from humans and the proportion of bites upon unprotected humans occurring indoors also suggest optimal target product profiles for delivering insecticides to humans or livestock. For vectors that feed only occasionally upon humans, preferred animal hosts may be optimal targets for mosquito-toxic insecticides, and vapour-phase insecticides optimized to maximize repellency, rather than toxicity, may be ideal for directly protecting people against indoor and outdoor exposure. However, for vectors that primarily feed upon people, repellent vapour-phase insecticides may be inferior to toxic ones and may undermine the impact of contact insecticides applied to human sleeping spaces, houses or clothing if combined in the same time and place. These concepts are also applicable to other mosquito-borne anthroponoses so that diverse target species could be simultaneously controlled with integrated vector management programmes. Measurements of these two crucial mosquito behavioural parameters should now be integrated into programmatically funded, longitudinal, national-scale entomological monitoring systems to inform selection of available technologies and investment in developing new ones. PMID:24739261

Killeen, Gerry F; Seyoum, Aklilu; Gimnig, John E; Stevenson, Jennifer C; Drakeley, Christopher J; Chitnis, Nakul

2014-01-01

154

Made-to-measure malaria vector control strategies: rational design based on insecticide properties and coverage of blood resources for mosquitoes  

PubMed Central

Eliminating malaria from highly endemic settings will require unprecedented levels of vector control. To suppress mosquito populations, vector control products targeting their blood hosts must attain high biological coverage of all available sources, rather than merely high demographic coverage of a targeted resource subset, such as humans while asleep indoors. Beyond defining biological coverage in a measurable way, the proportion of blood meals obtained from humans and the proportion of bites upon unprotected humans occurring indoors also suggest optimal target product profiles for delivering insecticides to humans or livestock. For vectors that feed only occasionally upon humans, preferred animal hosts may be optimal targets for mosquito-toxic insecticides, and vapour-phase insecticides optimized to maximize repellency, rather than toxicity, may be ideal for directly protecting people against indoor and outdoor exposure. However, for vectors that primarily feed upon people, repellent vapour-phase insecticides may be inferior to toxic ones and may undermine the impact of contact insecticides applied to human sleeping spaces, houses or clothing if combined in the same time and place. These concepts are also applicable to other mosquito-borne anthroponoses so that diverse target species could be simultaneously controlled with integrated vector management programmes. Measurements of these two crucial mosquito behavioural parameters should now be integrated into programmatically funded, longitudinal, national-scale entomological monitoring systems to inform selection of available technologies and investment in developing new ones. PMID:24739261

2014-01-01

155

Investigating the Potential Range Expansion of the Vector Mosquito Aedes Aegypti in Mexico with NASA Earth Science Remote Sensing Results  

NASA Technical Reports Server (NTRS)

In tropical and sub ]tropical regions, the mosquito Aedes aegypti is the major vector for the virus causing dengue, a serious public health issue in these areas. Through ongoing NSF- and NASA-funded studies, field surveys of Aedes aegypti and an integrated modeling approach are being used to improve our understanding of the potential range of the mosquito to expand toward heavily populated high elevation areas such as Mexico City under various climate change and socio ]economic scenarios. This work serves three primary objectives: (1) Employ NASA remotely-sensed data to supplement the environmental monitoring and modeling component of the project. These data-- for example, surface temperature, precipitation, vegetation indices, soil moisture and elevation-- are critical for understanding the habitat necessary for mosquito survival and abundance; (2) Implement training sessions to instruct scientists and students from Mexico and the U.S. on how to use remote sensing and implement the NASA SERVIR Regional Visualization and Monitoring System; (3) Employ the SERVIR framework to optimize the dissemination of key project results in order to increase their societal relevance and benefits in developing climate adaptation strategies. Field surveys of larval, pupal and adult Aedes aegypti, as well as detailed physical and social household characteristics, were conducted in the summers of 2011and 2012 at geographic scales from the household to the community along a transect from sea level to 2400 m ASL. These data are being used in models to estimate Aedes aegypti habitat suitability. In 2011, Aedes aegypti were identified at an elevation of over 2150 m in Puebla, the highest elevation at which this species has been observed.

Crosson, W. L.; Estes, M. G.; Estes, S. M.; Hayden, M.; Monaghan, A. J.; Eisen, L.; Lozano-Fuentes, S.; Ochoa, C.; Tapia, B.; Welsh-Rodriquez, C. M.; Quattrochi, D.; MorenoMadrinan, M. J.

2012-01-01

156

Investigating the Potential Range Expansion of the Vector Mosquito Aedes aegypti in Mexico with NASA Earth Science Remote Sensing Results  

NASA Astrophysics Data System (ADS)

In tropical and sub-tropical regions, the mosquito Aedes aegypti is the major vector for the virus causing dengue, a serious public health issue in these areas. Through ongoing NSF- and NASA-funded studies, field surveys of Aedes aegypti and an integrated modeling approach are being used to improve our understanding of the potential range of the mosquito to expand toward heavily populated high elevation areas such as Mexico City under various climate change and socio-economic scenarios. This work serves three primary objectives: (1) Employ NASA remotely-sensed data to supplement the environmental monitoring and modeling component of the project. These data -- for example, surface temperature, precipitation, vegetation indices, soil moisture and elevation -- are critical for understanding the habitat necessary for mosquito survival and abundance; (2) Implement training sessions to instruct scientists and students from Mexico and the U.S. on how to use remote sensing and implement the NASA SERVIR Regional Visualization and Monitoring System; (3) Employ the SERVIR framework to optimize the dissemination of key project results in order to increase their societal relevance and benefits in developing climate adaptation strategies. Field surveys of larval, pupal and adult Aedes aegypti, as well as detailed physical and social household characteristics, were conducted in the summers of 2011and 2012 at geographic scales from the household to the community along a transect from sea level to 2400 m ASL. These data are being used in models to estimate Aedes aegypti habitat suitability. In 2011, Aedes aegypti were identified at an elevation of over 2150 m in Puebla, the highest elevation at which this species has been observed.

Crosson, W. L.; Eisen, L.; Estes, M. G.; Estes, S. M.; Hayden, M.; Lozano-Fuentes, S.; Monaghan, A. J.; Moreno Madrin, M. J.; Ochoa, C.; Quattrochi, D.; Tapia, B.; Welsh-Rodriguez, C. M.

2012-12-01

157

Molecular and Functional Characterization of Odorant-Binding Protein Genes in an Invasive Vector Mosquito, Aedes albopictus  

PubMed Central

Aedes albopictus is a major vector of dengue and Chikungunya viruses. Olfaction plays a vital role in guiding mosquito behaviors and contributes to their ability to transmit pathogens. Odorant-binding proteins (OBPs) are abundant in insect olfactory tissues and involved in the first step of odorant reception. While comprehensive descriptions are available of OBPs from Aedes aegypti, Culex quinquefasciatus and Anopheles gambiae, only a few genes from Ae. albopictus have been reported. In this study, twenty-one putative AalbOBP genes were cloned using their homologues in Ae. aegypti to query an Ae. albopictus partial genome sequence. Two antenna-specific OBPs, AalbOBP37 and AalbOBP39, display a remarkable similarity in their overall folding and binding pockets, according to molecular modeling. Binding affinity assays indicated that AalbOBP37 and AalbOBP39 had overlapping ligand affinities and are affected in different pH condition. Electroantennagrams (EAG) and behavioral tests show that these two genes were involved in olfactory reception. An improved understanding of the Ae. albopictus OBPs is expected to contribute to the development of more efficient and environmentally-friendly mosquito control strategies. PMID:23935894

Deng, Yuhua; Yan, Hui; Gu, Jinbao; Xu, Jiabao; Wu, Kun; Tu, Zhijian; James, Anthony A.; Chen, Xiaoguang

2013-01-01

158

[Examination of mosquitoes collected in southern Moravia in 2006-2008 tested for arboviruses].  

PubMed

The main goals of the study were to carry out virus isolation attempts on Vero cell cultures from mosquitoes collected in southern Moravia (Breclav district, Czech Republic) and to identify the isolates using a microtiter virus neutralization test. A total of 9.742 female mosquitoes belonging to 13 species were examined, and three viral strains were isolated, all from the mosquitoes collected in 2006: two of these isolates were identified as Tahyna Orthobunyavirus (both obtained from Aedes vexans mosquitoes) and one was West Nile flavivirus (obtained from Aedes rossicus mosquitoes). Ae. rossicus might be a new vector for West Nile virus. PMID:20925246

Kazdov, K; Hublek, Z

2010-08-01

159

A low-cost mesocosm for the study of behaviour and reproductive potential in Afrotropical mosquito (Diptera: Culicidae) vectors of malaria.  

PubMed

A large-scale mesocosm was constructed and tested for its effectiveness for use in experiments on behaviour, reproduction and adult survivorship in the Afrotropical malaria vector Anopheles gambiae s.s. Giles (Diptera: Culicidae) in temperate climates. The large space (82.69 m(3) ) allowed for semi-natural experiments that increased demand on a mosquito's energetic reserves in an environment of widely distributed resources. A one-piece prefabricated enclosure, made with white netting and vinyl, prevented the ingress of predators and the egress of mosquitoes. Daylight and white materials prompted the mosquitoes to seclude themselves in restricted daytime resting sites and allowed the easy collection of dead bodies so that daily mortality could be assessed accurately using a method that accounts for the loss of a proportion of bodies. Here, daily, age-dependent mortality rates of males and females were estimated using Bayesian Markov chain Monte Carlo simulation. In overnight experiments, mosquitoes successfully located plants and took sugar meals. A 3-week survival trial with a single cohort demonstrated successful mating, blood feeding, oviposition and long life. The relatively low cost of the mesocosm and the performance of the mosquitoes in it make it a viable option for any behavioural or ecological study of tropical mosquitoes in which space and seasonal cold are constraining factors. PMID:25294339

Jackson, B T; Stone, C M; Ebrahimi, B; Brit, O J T; Foster, W A

2015-03-01

160

Chemical composition and larvicidal activity of Blumea densiflora essential oils against Anopheles anthropophagus: a malarial vector mosquito.  

PubMed

Blumea densiflora, an edible and medicinal plant, is chiefly distributed in Southeast Asia and South Asia. Essential oils extracted by steam distillation from B. densiflora were investigated for their chemical composition and larvicidal activity against Anopheles anthropophagus, the primary vector of malaria in China and other East Asian countries. Totally, 46 compounds were identified by gas chromatography and mass spectroscopy. The major chemical compounds identified were borneol (11.43%), germacrene D (8.66%), ?-caryophyllene (6.68%), ?-terpinene (4.35%), sabinene (4.34%), and ?-bisabolene (4.24%). A series of concentrations of essential oil (that ranged from 6.25 to 150 ppm) were tested against A. anthropophagus fourth-instar larvae according to WHO recommendation. In general, larval mortality increased as concentration and exposure time increased, indicating a dose-dependent effect, and high insecticidal activity showed that 100% mortality occurred within 6 h at 150 ppm, 10 h at 100 ppm, 30 h at 50 ppm, and 30 h at 25 ppm essential oil concentration. The LC(50) values were 22.32 (after 12 h) and 10.55 ppm (after 24 h), and the LC(90) values were 54.04 (after 12 h) and 33.56 ppm (after 24 h). Pylarvex, the reference standard, had better larvicidal activity, causing 100% mortality within 2 h at 150 ppm and within 6 h at 6.25 ppm. The results clearly reveal that the essential oil of B. densiflora served as a potential, eco-friendly mosquito larvicide against the malarial vector mosquito A. anthropophagus. PMID:21556689

Zhu, Liang; Tian, Yingjuan

2011-11-01

161

Mosquito larvicidal activity of Aloe vera (Family: Liliaceae) leaf extract and Bacillus sphaericus, against Chikungunya vector, Aedes aegypti  

PubMed Central

The bio-efficacy of Aloe vera leaf extract and bacterial insecticide, Bacillus sphaericus larvicidal activity was assessed against the first to fourth instars larvae of Aedes aegypti, under the laboratory conditions. The plant material was shade dried at room temperature and powdered coarsely. A. vera and B. sphaericus show varied degrees of larvicidal activity against various instars larvae of A. aegypti. The LC50 of A. vera against the first to fourth instars larvae were 162.74, 201.43, 253.30 and 300.05ppm and the LC90 442.98, 518.86, 563.18 and 612.96ppm, respectively. B. sphaericus against the first to fourth instars larvae the LC50 values were 68.21, 79.13, 93.48, and 107.05ppm and the LC90 values 149.15, 164.67, 183.84, and 201.09ppm, respectively. However, the combined treatment of A. vera+B. sphaericus (1:2) material shows highest larvicidal activity of the LC50 values 54.80, 63.11, 74.66 and 95.10ppm; The LC90 values of 145.29, 160.14, 179.74 and 209.98ppm, against A. aegypti in all the tested concentrations than the individuals and clearly established that there is a substantial amount of synergist act. The present investigation clearly exhibits that both A. vera and B. sphaericus materials could serve as a potential larvicidal agent. Since, A. aegypti is a container breeder vector mosquito this user and eco-friendly and low-cost vector control strategy could be a viable solution to the existing dengue disease burden. Therefore, this study provides first report on the mosquito larvicidal activity the combined effect of A. vera leaf extract and B. sphaericus against as target species of A. aegypti. PMID:23961212

Subramaniam, Jayapal; Kovendan, Kalimuthu; Mahesh Kumar, Palanisamy; Murugan, Kadarkarai; Walton, William

2012-01-01

162

Cell phone-based system (Chaak) for surveillance of immatures of dengue virus mosquito vectors.  

PubMed

Capture of surveillance data on mobile devices and rapid transfer of such data from these devices into an electronic database or data management and decision support systems promote timely data analyses and public health response during disease outbreaks. Mobile data capture is used increasingly for malaria surveillance and holds great promise for surveillance of other neglected tropical diseases. We focused on mosquito-borne dengue, with the primary aims of: 1) developing and field-testing a cell phone-based system (called Chaak) for capture of data relating to the surveillance of the mosquito immature stages, and 2) assessing, in the dengue endemic setting of Mrida, Mexico, the cost-effectiveness of this new technology versus paper-based data collection. Chaak includes a desktop component, where a manager selects premises to be surveyed for mosquito immatures, and a cell phone component, where the surveyor receives the assigned tasks and captures the data. Data collected on the cell phone can be transferred to a central database through different modes of transmission, including near-real time where data are transferred immediately (e.g., over the Internet) or by first storing data on the cell phone for future transmission. Spatial data are handled in a novel, semantically driven, geographic information system. Compared with a pen-and-paper-based method, use of Chaak improved the accuracy and increased the speed of data transcription into an electronic database. The cost-effectiveness of using the Chaak system will depend largely on the up-front cost of purchasing cell phones and the recurring cost of data transfer over a cellular network. PMID:23926788

Lozano-Fuentes, Saul; Wedyan, Fadi; Hernandez-Garcia, Edgar; Sadhu, Devadatta; Ghosh, Sudipto; Bieman, James M; Tep-Chel, Diana; Garca-Rejn, Julin E; Eisen, Lars

2013-07-01

163

Replacing a native Wolbachia with a novel strain results in an increase in endosymbiont load and resistance to dengue virus in a mosquito vector.  

PubMed

Wolbachia is a maternally transmitted endosymbiotic bacterium that is estimated to infect up to 65% of insect species. The ability of Wolbachia to both induce pathogen interference and spread into mosquito vector populations makes it possible to develop Wolbachia as a biological control agent for vector-borne disease control. Although Wolbachia induces resistance to dengue virus (DENV), filarial worms, and Plasmodium in mosquitoes, species like Aedes polynesiensis and Aedes albopictus, which carry native Wolbachia infections, are able to transmit dengue and filariasis. In a previous study, the native wPolA in Ae. polynesiensis was replaced with wAlbB from Ae. albopictus, and resulted in the generation of the transinfected "MTB" strain with low susceptibility for filarial worms. In this study, we compare the dynamics of DENV serotype 2 (DENV-2) within the wild type "APM" strain and the MTB strain of Ae. polynesiensis by measuring viral infection in the mosquito whole body, midgut, head, and saliva at different time points post infection. The results show that wAlbB can induce a strong resistance to DENV-2 in the MTB mosquito. Evidence also supports that this resistance is related to a dramatic increase in Wolbachia density in the MTB's somatic tissues, including the midgut and salivary gland. Our results suggests that replacement of a native Wolbachia with a novel infection could serve as a strategy for developing a Wolbachia-based approach to target naturally infected insects for vector-borne disease control. PMID:23755311

Bian, Guowu; Zhou, Guoli; Lu, Peng; Xi, Zhiyong

2013-01-01

164

Superior infectivity for mosquito vectors contributes to competitive displacement among strains of dengue virus  

Microsoft Academic Search

BACKGROUND: Competitive displacement of a weakly virulent pathogen strain by a more virulent strain is one route to disease emergence. However the mechanisms by which pathogens compete for access to hosts are poorly understood. Among vector-borne pathogens, variation in the ability to infect vectors may effect displacement. The current study focused on competitive displacement in dengue virus serotype 3 (DENV3),

Kathryn A Hanley; Jacob T Nelson; Erin E Schirtzinger; Stephen S Whitehead; Christopher T Hanson

2008-01-01

165

Ecological niche modelling of potential West Nile virus vector mosquito species and their geographical association with equine epizootics in Italy.  

PubMed

In Italy, West Nile virus (WNV) equine outbreaks have occurred annually since 2008. Characterizing WNV vector habitat requirements allows for the identification of areas at risk of viral amplification and transmission. Maxent-based ecological niche models were developed using literature records of 13 potential WNV Italian vector mosquito species to predict their habitat suitability range and to investigate possible geographical associations with WNV equine outbreak occurrence in Italy from 2008 to 2010. The contribution of different environmental variables to the niche models was also assessed. Suitable habitats for Culex pipiens, Aedes albopictus, and Anopheles maculipennis were widely distributed; Culex modestus, Ochlerotatus geniculatus, Ochlerotatus caspius, Coquillettidia richiardii, Aedes vexans, and Anopheles plumbeus were concentrated in north-central Italy; Aedes cinereus, Culex theileri, Ochlerotatus dorsalis, and Culiseta longiareolata were restricted to coastal/southern areas. Elevation, temperature, and precipitation variables showed the highest predictive power. Host population and landscape variables provided minor contributions. WNV equine outbreaks had a significantly higher probability to occur in habitats suitable for Cx. modestus and Cx. pipiens, providing circumstantial evidence that the potential distribution of these two species coincides geographically with the observed distribution of the disease in equines. PMID:24121802

Mughini-Gras, Lapo; Mulatti, Paolo; Severini, Francesco; Boccolini, Daniela; Romi, Roberto; Bongiorno, Gioia; Khoury, Cristina; Bianchi, Riccardo; Montarsi, Fabrizio; Patregnani, Tommaso; Bonfanti, Lebana; Rezza, Giovanni; Capelli, Gioia; Busani, Luca

2014-03-01

166

Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar  

PubMed Central

Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 10-16) and period (F = 36.22, p = 2.548 10-13), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. Conclusion In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion. PMID:22433186

2012-01-01

167

The Effect of Virus-Blocking Wolbachia on Male Competitiveness of the Dengue Vector Mosquito, Aedes aegypti  

PubMed Central

Background The bacterial endosymbiont Wolbachia blocks the transmission of dengue virus by its vector mosquito Aedes aegypti, and is currently being evaluated for control of dengue outbreaks. Wolbachia induces cytoplasmic incompatibility (CI) that results in the developmental failure of offspring in the cross between Wolbachia-infected males and uninfected females. This increases the relative success of infected females in the population, thereby enhancing the spread of the beneficial bacterium. However, Wolbachia spread via CI will only be feasible if infected males are sufficiently competitive in obtaining a mate under field conditions. We tested the effect of Wolbachia on the competitiveness of A. aegypti males under semi-field conditions. Methodology/Principal Findings In a series of experiments we exposed uninfected females to Wolbachia-infected and uninfected males simultaneously. We scored the competitiveness of infected males according to the proportion of females producing non-viable eggs due to incompatibility. We found that infected males were equally successful to uninfected males in securing a mate within experimental tents and semi-field cages. This was true for males infected by the benign wMel Wolbachia strain, but also for males infected by the virulent wMelPop (popcorn) strain. By manipulating male size we found that larger males had a higher success than smaller underfed males in the semi-field cages, regardless of their infection status. Conclusions/Significance The results indicate that Wolbachia infection does not reduce the competitiveness of A. aegypti males. Moreover, the body size effect suggests a potential advantage for lab-reared Wolbachia-males during a field release episode, due to their better nutrition and larger size. This may promote Wolbachia spread via CI in wild mosquito populations and underscores its potential use for disease control. PMID:25502564

Segoli, Michal; Hoffmann, Ary A.; Lloyd, Jane; Omodei, Gavin J.; Ritchie, Scott A.

2014-01-01

168

Barcoding Turkish Culex mosquitoes to facilitate arbovirus vector incrimination studies reveals hidden diversity and new potential vectors.  

PubMed

As a precursor to planned arboviral vector incrimination studies, an integrated systematics approach was adopted using morphology and DNA barcoding to examine the Culex fauna present in Turkey. The mitochondrial COI gene (658bp) were sequenced from 185 specimens collected across 11 Turkish provinces, as well as from colony material. Although by morphology only 9 species were recognised, DNA barcoding recovered 13 distinct species including: Cx. (Barraudius) modestus, Cx. (Culex) laticinctus, Cx. (Cux.) mimeticus, Cx. (Cux.) perexiguus, Cx. (Cux.) pipiens, Cx. (Cux.) pipiens form molestus, Cx. (Cux.) quinquefasciatus, Cx. (Cux.) theileri, Cx. (Cux.) torrentium, Cx. (Cux.) tritaeniorhynchus and Cx. (Maillotia) hortensis. The taxon formerly identified as Cx. (Neoculex) territans was shown to comprise two distinct species, neither of which correspond to Cx. territans s.s. These include Cx. (Neo.) impudicus and another uncertain species, which may be Cx. (Neo.) europaeus or Cx. (Neo.) martinii (herein=Cx. (Neo.) sp. 1). Detailed examination of the Pipiens Group revealed Cx. pipiens, Cx. pipiens f. molestus and the widespread presence of the highly efficient West Nile virus vector Cx. quinquefasciatus for the first time. Four new country records are reported, increasing the Culex of Turkey to 15 recognised species and Cx. pipiens f. molestus. A new taxonomic checklist is provided, annotated with respective vector competencies for transmission of arboviruses. PMID:25446171

Gunay, Filiz; Alten, Bulent; Simsek, Fatih; Aldemir, Adnan; Linton, Yvonne-Marie

2015-03-01

169

Application of mosquito sampling count and geospatial methods to improve dengue vector surveillance.  

PubMed

Dengue hemorrhagic fever is a major public health problem in several countries around the world. Dengue vector surveillance is an important methodology to determine when and where to take the control action. We used a combination of the Global Positioning System (GPS)/Geographic Information System (GIS) technology and the immature sampling count method to improve dengue vector surveillance. Both complete count and sampling count methods were used simultaneously to collect immature dengue vectors in all houses and all containers in one village in eastern Thailand to determine the efficiency of the sampling count technique. A hand-held GPS unit was used to record the location of surveyed houses. Linear regression indicated a high correlation between total immature populations resulting from the complete count and estimates from sampling count of immature stages. The immature survey data and the GPS coordinates of house location were combined into GIS maps showing distribution of immature density and clustering of immature stages and positive containers in the study area. This approach could be used to improve the efficiency and accuracy of dengue vector surveillance for targeting vector control. PMID:17984350

Chansang, Chitti; Kittayapong, Pattamaporn

2007-11-01

170

Mosquito Immunity against Arboviruses  

PubMed Central

Arthropod-borne viruses (arboviruses) pose a significant threat to global health, causing human disease with increasing geographic range and severity. The recent availability of the genome sequences of medically important mosquito species has kick-started investigations into the molecular basis of how mosquito vectors control arbovirus infection. Here, we discuss recent findings concerning the role of the mosquito immune system in antiviral defense, interactions between arboviruses and fundamental cellular processes such as apoptosis and autophagy, and arboviral suppression of mosquito defense mechanisms. This knowledge provides insights into co-evolutionary processes between vector and virus and also lays the groundwork for the development of novel arbovirus control strategies that target the mosquito vector. PMID:25415198

Sim, Shuzhen; Jupatanakul, Natapong; Dimopoulos, George

2014-01-01

171

Anti-mosquito plants as an alternative or incremental method for malaria vector control among rural communities of Bagamoyo District, Tanzania  

PubMed Central

Background Plants represent one of the most accessible resources available for mosquito control by communities in Tanzania. However, no documented statistics exist for their contribution in the management of mosquitoes and other insects except through verbal and some publications. This study aimed at assessing communities knowledge, attitudes and practices of using plants as an alternative method for mosquito control among selected communities in a malaria-prone area in Tanzania. Methods Questionnaires were administered to 202 respondents from four villages of Bagamoyo District, Pwani Region, in Tanzania followed by participatory rural appraisal with village health workers. Secondary data collection for plants mentioned by the communities was undertaken using different search engines such as googlescholar, PubMED and NAPRALERT. Results Results showed about 40.3% of respondents used plants to manage insects, including mosquitoes. A broad profile of plants are used, including mwarobaini (Azadirachta indica) (22.5%), mtopetope (Annona spp) (20.8%), mchungwa/mlimau (Citrus spp) (8.3%), mvumbashi/uvumbati (Ocimum spp) (7.4%), mkorosho (Anacadium occidentale) (7.1%), mwembe (5.4%) (Mangifera indica), mpera (4.1%) (Psidium spp) and maganda ya nazi (4.1%) (Cocos nucifera). Majority of respondents collected these plants from the wild (54.2%), farms (28.9%) and/or home gardens (6%). The roles played by these plants in fighting mosquitoes is reflected by the majority that deploy them with or without bed-nets (p > 0.55) or insecticidal sprays (p >0.22). Most respondents were aware that mosquitoes transmit malaria (90.6%) while few respondents associated elephantiasis/hydrocele (46.5%) and yellow fever (24.3%) with mosquitoes. Most of the ethnobotanical uses mentioned by the communities were consistent with scientific information gathered from the literature, except for Psidium guajava, which is reported for the first time in insect control. Conclusion This survey has indicated some knowledge gap among community members in managing mosquito vectors using plant. The communities need a basic health education and sensitization for effective exploitation of this valuable tool for reducing mosquitoes and associated disease burdens. On the other hand, the government of Tanzania should strengthen advocacy of botanical pesticides development, registration and regulation for public health benefits because they are source of pest control tools people rely on them. PMID:25015092

2014-01-01

172

Aromatic plant-derived essential oil: an alternative larvicide for mosquito control.  

PubMed

Five aromatic plants, Carum carvi (caraway), Apium graveolens (celery), Foeniculum vulgare (fennel), Zanthoxylum limonella (mullilam) and Curcuma zedoaria (zedoary) were selected for investigating larvicidal potential against mosquito vectors. Two laboratory-reared mosquito species, Anopheles dirus, the major malaria vector in Thailand, and Aedes aegypti, the main vector of dengue and dengue hemorrhagic fever in urban areas, were used. All of the volatile oils exerted significant larvicidal activity against the two mosquito species after 24-h exposure. Essential oil from mullilam was the most effective against the larvae of A. aegypti, while A. dirus larvae showed the highest susceptibility to zedoary oil. PMID:17337133

Pitasawat, B; Champakaew, D; Choochote, W; Jitpakdi, A; Chaithong, U; Kanjanapothi, D; Rattanachanpichai, E; Tippawangkosol, P; Riyong, D; Tuetun, B; Chaiyasit, D

2007-04-01

173

Yellow Fever Virus in Haemagogus leucocelaenus and Aedes serratus Mosquitoes, Southern Brazil, 2008  

PubMed Central

Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil. In October 2008, a yellow fever outbreak was reported there, with nonhuman primate deaths and human cases. This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs. We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths. Mosquitoes were collected at ground level, identified, and processed for virus isolation and molecular analyses. Eight YFV strains were isolated (7 from pools of Hg. leucocelaenus mosquitoes and another from Aedes serratus mosquitoes); 6 were sequenced, and they grouped in the YFV South American genotype I. The results confirmed the role of Hg. leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae. serratus mosquitoes may have a potential role as a secondary vector. PMID:21122222

Cardoso, Jder da C.; de Almeida, Marco A.B.; dos Santos, Edmilson; da Fonseca, Daltro F.; Sallum, Maria A.M.; Noll, Carlos A.; Monteiro, Hamilton A. de O.; Cruz, Ana C.R.; Carvalho, Valria L.; Pinto, Eliana V.; Castro, Francisco C.; Neto, Joaquim P. Nunes; Segura, Maria N.O.

2010-01-01

174

Efficient transformation of the yellow fever mosquito Aedes aegypti using the piggyBac transposable element vector pBac[3xP3-EGFP afm  

Microsoft Academic Search

We report efficient germ-line transformation in the yellow fever mosquito Aedes aegypti accomplished using the piggyBac transposable element vector pBac[3xP3-EGFP afm]. Two transgenic lines were established and characterized; each contained the Vg-Defensin A transgene with strong eye-specific expression of the enhanced green fluorescent protein (EGFP) marker gene regulated by the artificial 3xP3 promoter. Southern blot hybridization and inverse PCR analyses

V. Kokoza; A. Ahmed; E. A. Wimmer; A. S. Raikhel

2001-01-01

175

Molecular basis of odor coding in the malaria vector mosquito Anopheles gambiae.  

PubMed

A systematic functional analysis across much of the conventional Anopheles gambiae odorant receptor (AgOR) repertoire was carried out in Xenopus oocytes using two-electrode, voltage-clamp electrophysiology. The resulting data indicate that each AgOR manifests a distinct odor-response profile and tuning breadth. The large diversity of tuning responses ranges from AgORs that are responsive to a single or small number of odorants (specialists) to more broadly tuned receptors (generalists). Several AgORs were identified that respond robustly to a range of human volatiles that may play a critical role in anopheline host selection. AgOR responses were analyzed further by constructing a multidimensional odor space representing the relationships between odorants and AgOR responses. Within this space, the distance between odorants is related to both chemical class and concentration and may correlate with olfactory discrimination. This study provides a comprehensive overview of olfactory coding mechanisms of An. gambiae that ultimately may aid in fostering the design and development of olfactory-based strategies for reducing the transmission of malaria and other mosquito-borne diseases. PMID:20160092

Wang, Guirong; Carey, Allison F; Carlson, John R; Zwiebel, Laurence J

2010-03-01

176

September 2012 The tiger mosquito  

E-print Network

N° 412 September 2012 The tiger mosquito is more flighty than first thought Scientific news Actualidad cientifica Actualité scientifique Female tiger mosquitoes, the vectors of the chikun- gunya virus in previous studies, male mosquitoes sterilised by radiation2 in the laboratory nevertheless succeeded

177

Dengue Vector Mosquitoes at a Tourist Attraction, Ko Samui, in 1995  

Microsoft Academic Search

On Ko Samui, Thailand there were two epidemics of dengue hemorrhagic fever (DHF) in 1966 and 1967, followed by endemics up to 1994. Aedes aegypti and Aedes albopictus were the vectors. From January to July 1995, 51 cases of DHF were reported, out of these were many foreigners who still suffer from dengue fever and return home with negative impression.

Usavadee Thavara; Apiwat Tawatsin; Prakong Phan-Urai; Wichai Kong-ngamsuk; Chitti Chansang; Liu Mingtuan; Li Zhijun

178

MIRO and IRbase: IT Tools for the Epidemiological Monitoring of Insecticide Resistance in Mosquito Disease Vectors  

Microsoft Academic Search

BackgroundMonitoring of insect vector populations with respect to their susceptibility to one or more insecticides is a crucial element of the strategies used for the control of arthropod-borne diseases. This management task can nowadays be achieved more efficiently when assisted by IT (Information Technology) tools, ranging from modern integrated databases to GIS (Geographic Information System). Here we describe an application

Emmanuel Dialynas; Pantelis Topalis; John Vontas; Christos Louis

2009-01-01

179

Large fluctuations in the effective population size of the malaria mosquito Anopheles gambiae s.s. during vector control cycle  

PubMed Central

On Bioko Island, Equatorial Guinea, indoor residual spraying (IRS) has been part of the Bioko Island Malaria Control Project since early 2004. Despite success in reducing childhood infections, areas of high transmission remain on the island. We therefore examined fluctuations in the effective population size (Ne) of the malaria vector Anopheles gambiae in an area of persistent high transmission over two spray rounds. We analyzed data for 13 microsatellite loci from 791 An.gambiae specimens collected at six time points in 2009 and 2010 and reconstructed the demographic history of the population during this period using approximate Bayesian computation (ABC). Our analysis shows that IRS rounds have a large impact on Ne, reducing it by 65%92% from prespray round Ne. More importantly, our analysis shows that after 35months, the An.gambiae population rebounded by 2818% compared shortly following the spray round. Our study underscores the importance of adequate spray round frequency to provide continuous suppression of mosquito populations and that increased spray round frequency should substantially improve the efficacy of IRS campaigns. It also demonstrates the ability of ABC to reconstruct a detailed demographic history across only a few tens of generations in a large population. PMID:24478799

Hodges, Theresa K; Athrey, Giridhar; Deitz, Kevin C; Overgaard, Hans J; Matias, Abrahan; Caccone, Adalgisa; Slotman, Michel A

2013-01-01

180

Heritability and adaptive phenotypic plasticity of adult body size in the mosquito Aedes aegypti with implications for dengue vector competence  

PubMed Central

Adaptive phenotypic plasticity is particularly important to organisms with developmental cycles that undergo ontogenetic niche shifts that differentially subject individual life stages to heterogeneous and often stressful environmental conditions. The yellow fever and dengue fever vector mosquito, Aedes aegypti, typically breeds in small water-filled containers that expose the developing aquatic larvae to competition for resources with conspecifics and high probabilities for habitat drying. Here we investigated the heritability (h2) and phenotypic plasticity among Aedes aegypti laboratory populations and field populations from Trinidad, West Indies. Heritability for body size was moderate or completely eroded among the laboratory populations, while field populations contained high genetic variation among both males and females. Norms of reactions based on optimum vs. deficient larval conditions for artificial sibling families representing Trinidad field populations suggested significant gene environment interactions influence body size and that there may be sex specific differences in allocation of resources. Individuals reared under optimum laboratory conditions were significantly larger and showed much less variability in body size plasticity than their field reared cohorts, suggesting that exposure to environmental stress may be common for Aedes aegypti larval development and would undoubtedly impact other traits, including arbovirus vector competence among adult females, in a similar fashion. Broad genetic variance in body size and other characters is likely maintained by balancing selection. Our results also suggest the need for caution in translating conclusions from experiments with laboratory colonies to natural populations. These would likely be more informative to expected phenotypes under natural conditions if conducted over a range of conditions that simulate environmental stress. PMID:21070891

Schneider, Jennifer R.; Chadee, Dave D.; Mori, Akio; Romero-Severson, Jeanne; Severson, David W.

2010-01-01

181

Septiembre de 2012 El mosquito tigre  

E-print Network

N° 412 Septiembre de 2012 El mosquito tigre: más promiscuo de lo previsto Scientific news Actualidad cientifica Actualité scientifique Los mosquitos tigre hembra, que transmiten el virus chikungunya los mosquitos machos, permitiría reducir la población de mosquitos vectores presente en la naturaleza

182

wFlu: Characterization and Evaluation of a Native Wolbachia from the Mosquito Aedes fluviatilis as a Potential Vector Control Agent  

PubMed Central

There is currently considerable interest and practical progress in using the endosymbiotic bacteria Wolbachia as a vector control agent for human vector-borne diseases. Such vector control strategies may require the introduction of multiple, different Wolbachia strains into target vector populations, necessitating the identification and characterization of appropriate endosymbiont variants. Here, we report preliminary characterization of wFlu, a native Wolbachia from the neotropical mosquito Aedes fluviatilis, and evaluate its potential as a vector control agent by confirming its ability to cause cytoplasmic incompatibility, and measuring its effect on three parameters determining host fitness (survival, fecundity and fertility), as well as vector competence (susceptibility) for pathogen infection. Using an aposymbiotic strain of Ae. fluviatilis cured of its native Wolbachia by antibiotic treatment, we show that in its natural host wFlu causes incomplete, but high levels of, unidirectional cytoplasmic incompatibility, has high rates of maternal transmission, and no detectable fitness costs, indicating a high capacity to rapidly spread through host populations. However, wFlu does not inhibit, and even enhances, oocyst infection with the avian malaria parasite Plasmodium gallinaceum. The stage- and sex-specific density of wFlu was relatively low, and with limited tissue distribution, consistent with the lack of virulence and pathogen interference/symbiont-mediated protection observed. Unexpectedly, the density of wFlu was also shown to be specifically-reduced in the ovaries after bloodfeeding Ae. fluviatilis. Overall, our observations indicate that the Wolbachia strain wFlu has the potential to be used as a vector control agent, and suggests that appreciable mutualistic coevolution has occurred between this endosymbiont and its natural host. Future work will be needed to determine whether wFlu has virulent host effects and/or exhibits pathogen interference when artificially-transfected to the novel mosquito hosts that are the vectors of human pathogens. PMID:23555728

Gonalves, Daniela da Silva; Moreira, Luciano Andrade

2013-01-01

183

Ovicidal, larvicidal and adulticidal properties of Asparagus racemosus (Willd.) (Family: Asparagaceae) root extracts against filariasis (Culex quinquefasciatus), dengue (Aedes aegypti) and malaria (Anopheles stephensi) vector mosquitoes (Diptera: Culicidae).  

PubMed

Several diseases are associated to the mosquito-human interaction. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikungunya fever, West Nile virus and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. The present investigation was undertaken to study the ovicidal, larvicidal and adulticidal activities of crude hexane, ethyl acetate, benzene, chloroform and methanol extracts of root of Asparagus racemosus were assayed for their toxicity against three important vector mosquitoes, viz., Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae). The mean percent hatchability of the eggs was observed after 48 h post-treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. All the five solvent extracts showed moderate ovicidal activity; however, the methanol extract showed the highest ovicidal activity. The methanol extract of Asparagus racemosus against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi exerted 100% mortality (zero hatchability) at 375, 300 and 225 ppm, respectively. Control eggs showed 99-100% hatchability. The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in methanol extract of root of Asparagus racemosus against the larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi with the LC50 and LC90 values were 115.13, 97.71 and 90.97 ppm and 210.96, 179.92, and 168.82 ppm, respectively. The adult mortality was observed after 24 h recovery period. The plant crude extracts showed dose-dependent mortality. At higher concentrations, the adult showed restless movement for some times with abnormal wagging and then died. Among the extracts tested, the highest adulticidal activity was observed in methanol extract against Anopheles stephensi followed by Aedes aegypti and Culex quinquefasciatus with the LD50 and LD90 values were 120.44, 135.60, and 157.71 ppm and 214.65, 248.35, and 290.95 ppm, respectively. No mortality was recorded in the control. The finding of the present investigation revealed that the root extract of Asparagus racemosus possess remarkable ovicidal, larvicidal and adulticidal activity against medically important vector mosquitoes and this is the low cost and ideal eco-friendly approach for the control of mosquitoes. This is the first report on the mosquito ovicidal, larvicidal and adulticidal activities of the reported Asparagus racemosus root. PMID:24488078

Govindarajan, Marimuthu; Sivakumar, Rajamohan

2014-04-01

184

Mechanisms of pyrethroid resistance in the dengue mosquito vector, Aedes aegypti: target site insensitivity, penetration, and metabolism.  

PubMed

Aedes aegypti is the major vector of yellow and dengue fevers. After 10 generations of adult selection, an A. aegypti strain (SP) developed 1650-fold resistance to permethrin, which is one of the most widely used pyrethroid insecticides for mosquito control. SP larvae also developed 8790-fold resistance following selection of the adults. Prior to the selections, the frequencies of V1016G and F1534C mutations in domains II and III, respectively, of voltage-sensitive sodium channel (Vssc, the target site of pyrethroid insecticide) were 0.44 and 0.56, respectively. In contrast, only G1016 alleles were present after two permethrin selections, indicating that G1016 can more contribute to the insensitivity of Vssc than C1534. In vivo metabolism studies showed that the SP strain excreted permethrin metabolites more rapidly than a susceptible SMK strain. Pretreatment with piperonyl butoxide caused strong inhibition of excretion of permethrin metabolites, suggesting that cytochrome P450 monooxygenases (P450s) play an important role in resistance development. In vitro metabolism studies also indicated an association of P450s with resistance. Microarray analysis showed that multiple P450 genes were over expressed during the larval and adult stages in the SP strain. Following quantitative real time PCR, we focused on two P450 isoforms, CYP9M6 and CYP6BB2. Transcription levels of these P450s were well correlated with the rate of permethrin excretion and they were certainly capable of detoxifying permethrin to 4'-HO-permethrin. Over expression of CYP9M6 was partially due to gene amplification. There was no significant difference in the rate of permethrin reduction from cuticle between SP and SMK strains. PMID:24945250

Kasai, Shinji; Komagata, Osamu; Itokawa, Kentaro; Shono, Toshio; Ng, Lee Ching; Kobayashi, Mutsuo; Tomita, Takashi

2014-06-01

185

Mechanisms of Pyrethroid Resistance in the Dengue Mosquito Vector, Aedes aegypti: Target Site Insensitivity, Penetration, and Metabolism  

PubMed Central

Aedes aegypti is the major vector of yellow and dengue fevers. After 10 generations of adult selection, an A. aegypti strain (SP) developed 1650-fold resistance to permethrin, which is one of the most widely used pyrethroid insecticides for mosquito control. SP larvae also developed 8790-fold resistance following selection of the adults. Prior to the selections, the frequencies of V1016G and F1534C mutations in domains II and III, respectively, of voltage-sensitive sodium channel (Vssc, the target site of pyrethroid insecticide) were 0.44 and 0.56, respectively. In contrast, only G1016 alleles were present after two permethrin selections, indicating that G1016 can more contribute to the insensitivity of Vssc than C1534. In vivo metabolism studies showed that the SP strain excreted permethrin metabolites more rapidly than a susceptible SMK strain. Pretreatment with piperonyl butoxide caused strong inhibition of excretion of permethrin metabolites, suggesting that cytochrome P450 monooxygenases (P450s) play an important role in resistance development. In vitro metabolism studies also indicated an association of P450s with resistance. Microarray analysis showed that multiple P450 genes were over expressed during the larval and adult stages in the SP strain. Following quantitative real time PCR, we focused on two P450 isoforms, CYP9M6 and CYP6BB2. Transcription levels of these P450s were well correlated with the rate of permethrin excretion and they were certainly capable of detoxifying permethrin to 4?-HO-permethrin. Over expression of CYP9M6 was partially due to gene amplification. There was no significant difference in the rate of permethrin reduction from cuticle between SP and SMK strains. PMID:24945250

Kasai, Shinji; Komagata, Osamu; Itokawa, Kentaro; Shono, Toshio; Ng, Lee Ching; Kobayashi, Mutsuo; Tomita, Takashi

2014-01-01

186

Comparative field evaluation of combinations of long-lasting insecticide treated nets and indoor residual spraying, relative to either method alone, for malaria prevention in an area where the main vector is Anopheles arabiensis  

PubMed Central

Background Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are commonly used together in the same households to improve malaria control despite inconsistent evidence on whether such combinations actually offer better protection than nets alone or IRS alone. Methods Comparative tests were conducted using experimental huts fitted with LLINs, untreated nets, IRS plus untreated nets, or combinations of LLINs and IRS, in an area where Anopheles arabiensis is the predominant malaria vector species. Three LLIN types, Olyset, PermaNet 2.0 and Icon Life nets and three IRS treatments, pirimiphos-methyl, DDT, and lambda cyhalothrin, were used singly or in combinations. We compared, number of mosquitoes entering huts, proportion and number killed, proportions prevented from blood-feeding, time when mosquitoes exited the huts, and proportions caught exiting. The tests were done for four months in dry season and another six months in wet season, each time using new intact nets. Results All the net types, used with or without IRS, prevented >99% of indoor mosquito bites. Adding PermaNet 2.0 and Icon Life, but not Olyset nets into huts with any IRS increased mortality of malaria vectors relative to IRS alone. However, of all IRS treatments, only pirimiphos-methyl significantly increased vector mortality relative to LLINs alone, though this increase was modest. Overall, median mortality of An. arabiensis caught in huts with any of the treatments did not exceed 29%. No treatment reduced entry of the vectors into huts, except for marginal reductions due to PermaNet 2.0 nets and DDT. More than 95% of all mosquitoes were caught in exit traps rather than inside huts. Conclusions Where the main malaria vector is An. arabiensis, adding IRS into houses with intact pyrethroid LLINs does not enhance house-hold level protection except where the IRS employs non-pyrethroid insecticides such as pirimiphos-methyl, which can confer modest enhancements. In contrast, adding intact bednets onto IRS enhances protection by preventing mosquito blood-feeding (even if the nets are non-insecticidal) and by slightly increasing mosquito mortality (in case of LLINs). The primary mode of action of intact LLINs against An. arabiensis is clearly bite prevention rather than insecticidal activity. Therefore, where resources are limited, priority should be to ensure that everyone at risk consistently uses LLINs and that the nets are regularly replaced before being excessively torn. Measures that maximize bite prevention (e.g. proper net sizes to effectively cover sleeping spaces, stronger net fibres that resist tears and burns and net use practices that preserve net longevity), should be emphasized. PMID:23433393

2013-01-01

187

Population Genetics of Two Key Mosquito Vectors of Rift Valley Fever Virus Reveals New Insights into the Changing Disease Outbreak Patterns in Kenya  

PubMed Central

Rift Valley fever (RVF) outbreaks in Kenya have increased in frequency and range to include northeastern Kenya where viruses are increasingly being isolated from known (Aedes mcintoshi) and newly-associated (Ae. ochraceus) vectors. The factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. By conducting mitochondrial and nuclear DNA analyses on >220 Kenyan specimens of Ae. mcintoshi and Ae. ochraceus, we uncovered high levels of vector complexity which may partly explain the disease outbreak pattern. Results indicate that Ae. mcintoshi consists of a species complex with one of the member species being unique to the newly-established RVF outbreak-prone northeastern region of Kenya, whereas Ae. ochraceus is a homogeneous population that appears to be undergoing expansion. Characterization of specimens from a RVF-prone site in Senegal, where Ae. ochraceus is a primary vector, revealed direct genetic links between the two Ae. ochraceus populations from both countries. Our data strongly suggest that unlike Ae. mcintoshi, Ae. ochraceus appears to be a relatively recent, single 'introduction' into Kenya. These results, together with increasing isolations from this vector, indicate that Ae. ochraceus will likely be of greater epidemiological importance in future RVF outbreaks in Kenya. Furthermore, the overall vector complexity calls into question the feasibility of mosquito population control approaches reliant on genetic modification. PMID:25474018

Tchouassi, David P.; Bastos, Armanda D. S.; Sole, Catherine L.; Diallo, Mawlouth; Lutomiah, Joel; Mutisya, James; Mulwa, Francis; Borgemeister, Christian; Sang, Rosemary; Torto, Baldwyn

2014-01-01

188

Population genetics of two key mosquito vectors of rift valley Fever virus reveals new insights into the changing disease outbreak patterns in kenya.  

PubMed

Rift Valley fever (RVF) outbreaks in Kenya have increased in frequency and range to include northeastern Kenya where viruses are increasingly being isolated from known (Aedes mcintoshi) and newly-associated (Ae. ochraceus) vectors. The factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. By conducting mitochondrial and nuclear DNA analyses on >220 Kenyan specimens of Ae. mcintoshi and Ae. ochraceus, we uncovered high levels of vector complexity which may partly explain the disease outbreak pattern. Results indicate that Ae. mcintoshi consists of a species complex with one of the member species being unique to the newly-established RVF outbreak-prone northeastern region of Kenya, whereas Ae. ochraceus is a homogeneous population that appears to be undergoing expansion. Characterization of specimens from a RVF-prone site in Senegal, where Ae. ochraceus is a primary vector, revealed direct genetic links between the two Ae. ochraceus populations from both countries. Our data strongly suggest that unlike Ae. mcintoshi, Ae. ochraceus appears to be a relatively recent, single 'introduction' into Kenya. These results, together with increasing isolations from this vector, indicate that Ae. ochraceus will likely be of greater epidemiological importance in future RVF outbreaks in Kenya. Furthermore, the overall vector complexity calls into question the feasibility of mosquito population control approaches reliant on genetic modification. PMID:25474018

Tchouassi, David P; Bastos, Armanda D S; Sole, Catherine L; Diallo, Mawlouth; Lutomiah, Joel; Mutisya, James; Mulwa, Francis; Borgemeister, Christian; Sang, Rosemary; Torto, Baldwyn

2014-12-01

189

Investigating the Potential Range Expansion of the Vector Mosquito Aedes Aegypti in Mexico with NASA Earth Science Remote Sensing Results  

NASA Technical Reports Server (NTRS)

Dengue (Breakbone) fever is caused by one of four viruses carried by mosquitoes in tropical and subtropical areas. Cases have increased dramatically in the past few decades; there are currently approximately 100 million infections annually around the globe. Our project will integrate environmental observations, including weather, land use, vegetation type, amount and greenness, soil moisture, and mosquito populations with investigations of the human dynamics of the system via household surveys.

Estes, Sue M.

2011-01-01

190

Field evaluation of the efficacy and persistence of insect repellents DEET, IR3535, and KBR 3023 against Anopheles gambiae complex and other Afrotropical vector mosquitoes.  

PubMed

Synthetic insect repellents, IR3535 and KBR 3023 (also known as picaridin, or by the trade name Bayrepel, were tested in Burkina Faso against mosquito vectors of disease to compare their relative efficacy and persistence profiles to those of the 'gold standard' DEET. Collection of >49000 mosquitoes (approximately 95% belonging to the Anopheles gambiae complex) showed that after an exposure of 10h, KBR 3023 produced the highest protection against anophelines, followed by DEET, then IR3535. The response of aedines was more variable. By fitting a logistic plane model we estimated 95% effective dosages (ED95) for An. gambiae s.l., as well as a decay constant characterizing the exponential loss of repellent from the skin, with time. The ED95 values for DEET, IR3535, and KBR 3023 were 94.3, 212.4, and 81.8 microg/cm2 respectively. The decay constants were estimated at -0.241, -0.240, and -0.170 h(-1) respectively. The corresponding estimates of half-life were 2.9, 2.9, and 4.1h. Immunoenzymatic detection of the circumsporozoite protein (CSP) of Plasmodium falciparum in 842 An. gambiae s.l. showed that CSP-positive mosquitoes were equally frequent in treated and control subjects, indicating that the repellents could produce a reduction in the number of malaria infectious bites. PMID:15363644

Costantini, Carlo; Badolo, Athanase; Ilboudo-Sanogo, Edith

2004-11-01

191

Collagen-binding protein, Aegyptin, regulates probing time and blood feeding success in the dengue vector mosquito, Aedes aegypti  

PubMed Central

Mosquito salivary glands have important roles in blood feeding and pathogen transmission. However, the biological relevance of many salivary components has yet to be determined. Aegyptin, a secreted salivary protein from Aedes aegypti, binds collagen and inhibits platelet aggregation and adhesion. We used a transgenic approach to study the relevance of Aegyptin in mosquito blood feeding. Aedes aegypti manipulated genetically to express gene-specific inverted-repeat RNA sequences exhibited significant reductions in Aegyptin mRNA accumulation (8587%) and protein levels (>80-fold) in female mosquito salivary glands. Transgenic mosquitoes had longer probing times (78300 s, P < 0.0001) when feeding on mice compared with controls (1556 s), feeding success was reduced, and those feeding took smaller blood meals. However, no differences in feeding success or blood meal size were found in membrane feeding experiments using defibrinated human blood. Salivary gland extracts from transgenic mosquitoes failed to inhibit collagen-induced platelet aggregation in vitro. Reductions of Aegyptin did not affect salivary ADP-induced platelet aggregation inhibition or disturb anticlotting activities. Our results demonstrate the relevance of Aegyptin for A. aegypti blood feeding, providing further support for the hypothesis that platelet aggregation inhibition is a vital salivary function in blood feeding arthropods. It has been suggested that the multiple mosquito salivary components mediating platelet aggregation (i.e., Aegyptin, apyrase, D7) represent functional redundancy. Our findings do not support this hypothesis; instead, they indicate that multiple salivary components work synergistically and are necessary to achieve maximum blood feeding efficiency. PMID:24778255

Chagas, Andrezza Campos; Ramirez, Jos Luis; Jasinskiene, Nijole; James, Anthony A.; Ribeiro, Jos M. C.; Marinotti, Osvaldo; Calvo, Eric

2014-01-01

192

Rapid Detection and Identification of Wuchereria bancrofti, Brugia malayi, B. pahangi, and Dirofilaria immitis in Mosquito Vectors and Blood Samples by High Resolution Melting Real-Time PCR  

PubMed Central

A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at 81.50.2?, 79.00.3?, 76.80.1?, and 79.90.1?, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors. PMID:24516268

Thanchomnang, Tongjit; Intapan, Pewpan M.; Tantrawatpan, Chairat; Lulitanond, Viraphong; Chungpivat, Sudchit; Taweethavonsawat, Piyanan; Kaewkong, Worasak; Sanpool, Oranuch; Janwan, Penchom; Choochote, Wej

2013-01-01

193

Role of Culex and Anopheles mosquito species as potential vectors of rift valley fever virus in Sudan outbreak, 2007  

Microsoft Academic Search

BACKGROUND: Rift Valley fever (RVF) is an acute febrile arthropod-borne viral disease of man and animals caused by a member of the Phlebovirus genus, one of the five genera in the family Bunyaviridae. RVF virus (RVFV) is transmitted between animals and human by mosquitoes, particularly those belonging to the Culex, Anopheles and Aedes genera. METHODS: Experiments were designed during RVF

AlaaEddeen M Seufi; Fatma H Galal

2010-01-01

194

An affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns  

PubMed Central

Background More sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. A large-scale larviciding programme in urban Dar es Salaam, Tanzania is supported by a community-based (CB) system for trapping adult mosquito densities to monitor programme performance. Methodology An intensive and extensive CB system for routine, longitudinal, programmatic surveillance of malaria vectors and other mosquitoes using the Ifakara Tent Trap (ITT-C) was developed in Urban Dar es Salaam, Tanzania, and validated by comparison with quality assurance (QA) surveys using either ITT-C or human landing catches (HLC), as well as a cross-sectional survey of malaria parasite prevalence in the same housing compounds. Results Community-based ITT-C had much lower sensitivity per person-night of sampling than HLC (Relative Rate (RR) [95% Confidence Interval (CI)]?=?0.079 [0.051, 0.121], P?vectors caught) and cost-effective (153US$ versus 187US$ per An. gambiae caught) because it allowed more spatially extensive and temporally intensive sampling (4284 versus 335 trap nights distributed over 615 versus 240 locations with a mean number of samples per year of 143 versus 141). Despite the very low vectors densities (Annual estimate of about 170 An gambiae s.l bites per person per year), CB-ITT was the only entomological predictor of parasite infection risk (Odds Ratio [95% CI]?=?4.43[3.027,7. 454] per An. gambiae or Anopheles funestus caught per night, P =0.0373). Discussion and conclusion CB trapping approaches could be improved with more sensitive traps, but already offer a practical, safe and affordable system for routine programmatic mosquito surveillance and clusters could be distributed across entire countries by adapting the sample submission and quality assurance procedures accordingly. PMID:22624853

2012-01-01

195

Ship ballast water as a main vector of marine introductions in the Mediterranean Sea  

Microsoft Academic Search

Marine invasive species are currently recognized as one of the most significant threats to global biodiversity. Marine bioinvasions\\u000a are more likely in the Mediterranean Sea because of its wide temperature range, degraded habitats, historical and high volume\\u000a of shipping traffic, and high occurrence of aquaculture. One of the main vectors of marine introductions globally and Mediterranean-wide\\u000a is commercial shipping. Of

Maria Monia Flagella; Ameer A. Abdulla

2005-01-01

196

Blood meal analysis, flavivirus screening, and influence of meteorological variables on the dynamics of potential mosquito vectors of West Nile virus in northern Italy.  

PubMed

An extended area of northern Italy has experienced several West Nile virus (WNV) outbreaks and the emergence of Usutu virus (USUV) during previous years. Our aim was to study some of the factors that could explain disease patterns in the Trentino region, where circulation was detected in human sera and sentinel chickens, but no human or equine cases were reported. We collected Culex species (Diptera: Culicidae) in peridomestic environments. The collected specimens were analyzed for feeding behavior, the influence of temperature and rainfall on the abundance of mosquitoes, and the occurrence of flaviviruses. Analysis of blood meals showed that Culex pipiens fed mainly on blackbirds (Turdus merula) and house sparrows (Passer domesticus), while Culex hortensis fed strictly on lizards. The abundance of Cx. pipiens females correlated positively with mean temperature and negatively with rainfall (one to four weeks before capture). This negative relationship could be due to the direct effect of the flushing of habitats together with an indirect effect of oviposition repellency. The mean weekly temperature influenced the abundance of Cx. hortensis. No flaviviruses were detected in the analyzed Culex mosquitoes. These data suggest a silent cycle at low enzootic transmission levels in the area. Furthermore, we present the first contribution to understanding the transmission role of Cx. pipiens mosquitoes in Italy by identifying vertebrate hosts to species level. PMID:22548533

Roiz, David; Vazquez, Ana; Ros, Roberto; Muoz, Joaquin; Arnoldi, Daniele; Rosso, Fausta; Figuerola, Jordi; Tenorio, Antonio; Rizzoli, Annapaola

2012-06-01

197

Wash resistance and bioefficacy of Olyset net--a long-lasting insecticide-treated mosquito net against malaria vectors and nontarget household pests.  

PubMed

During recent years, long-lasting insecticide-treated nets (LLINs) have been developed to overcome the problems of low retreatment rates, washing, and erratic dose of the insecticide resulting in the dilution of efficacy of the conventional insecticide-treated mosquito nets. These nets are treated at factory level with insecticide either incorporated into or coated around fibers. Olyset net, a polyethylene net with 2% permethrin incorporated within fibers, is one type of LLIN. Therefore, these nets were evaluated for their wash resistance and bioefficacy against malaria vectors Anopheles culicifacies Giles and Anopheles fluviatilis James (Diptera: Culicidae) and other nontarget species. Cone bioassay tests produced 100% mortality in these two vector species with 3-min exposure. Results of the bioassays on washed nets showed 100% mortality in An. fluviatilis even after 20 washings, whereas in An. culicifacies 100% mortality up to 11 washings and 80% mortality up to 20 washings were observed. Cone bioassay tests also were performed on nontarget mosquito species Culex quinquefasciatus Say; house fly, Musca domestica L.; American cockroach, Periplaneta americana (L.); head louse, Pediculus humanus capitis De Geer; and bed bug, Cimex lectularius L. with 30-min exposure. Except for bed bugs, 100% mortality was observed in these nontarget species after 24-h recovery period. In bed bugs, only 25% mortality was observed. The density of An. culicifacies and An. fluviatilis was significantly reduced in houses with Olyset nets compared with those with untreated nets or no nets. Thus, it may be concluded that Olyset nets are highly effective against malaria vectors and moderately against other nontarget household insects. PMID:17017224

Sharma, S K; Upadhyay, A K; Haque, M A; Padhan, K; Tyagi, P K; Ansari, M A; Dash, A P

2006-09-01

198

Chikungunya A mosquito-borne disease  

E-print Network

species are present in Florida · Aedes aegypti · Also called the Yellow Fever Mosquito · Aedes albopictus #12;Chikungunya Vector: Aedes aegypti, the Yellow Fever Mosquito #12;Larval habitats of container transmitted by mosquitoes · It is also called "contorted fever" and "that which bends up" · The virus

Florida, University of

199

INSECTICIDES RECOMMENDED FOR MOSQUITO CONTROL IN  

E-print Network

1 INSECTICIDES RECOMMENDED FOR MOSQUITO CONTROL IN NEW JERSEY IN 2012 L. B. Brattsten, Professor and proprietary examples APPENDIX: Best Management Practices for Mosquito Control in New Jersey New Jersey mosquito control commissions and agencies responsible for reducing the populations of nuisance and vector

Wang, Changlu

200

Using a new odour-baited device to explore options for luring and killing outdoor-biting malaria vectors: a report on design and field evaluation of the Mosquito Landing Box  

PubMed Central

Background Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the Mosquito Landing Box (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challenges relevant to luring and killing outdoor-biting malaria vectors in endemic settings. Methods Field experiments were conducted in Tanzania to assess if wild host-seeking mosquitoes 1) visited the MLBs, 2) stayed long or left shortly after arrival at the device, 3) visited the devices at times when humans were also outdoors, and 4) could be killed by contaminants applied on the devices. Odours suctioned from volunteer-occupied tents were also evaluated as a potential low-cost bait, by comparing baited and unbaited MLBs. Results There were significantly more Anopheles arabiensis, An. funestus, Culex and Mansonia mosquitoes visiting baited MLB than unbaited controls (P?0.028). Increasing sampling frequency from every 120 min to 60 and 30 min led to an increase in vector catches of up to 3.6 fold (P?0.002), indicating that many mosquitoes visited the device but left shortly afterwards. Outdoor host-seeking activity of malaria vectors peaked between 7:30 and 10:30pm, and between 4:30 and 6:00am, matching durations when locals were also outdoors. Maximum mortality of mosquitoes visiting MLBs sprayed or painted with formulations of candidate mosquitocidal agent (pirimiphos-methyl) was 51%. Odours from volunteer occupied tents attracted significantly more mosquitoes to MLBs than controls (P<0.001). Conclusion While odour-baited devices such as the MLBs clearly have potential against outdoor-biting mosquitoes in communities where LLINs are used, candidate contaminants must be those that are effective at ultra-low doses even after short contact periods, since important vector species such as An. arabiensis make only brief visits to such devices. Natural human odours suctioned from occupied dwellings could constitute affordable sources of attractants to supplement odour baits for the devices. The killing agents used should be environmentally safe, long lasting, and have different modes of action (other than pyrethroids as used on LLINs), to curb the risk of physiological insecticide resistance. PMID:23642306

2013-01-01

201

A reappraisal of the role of mosquitoes in the transmission of myxomatosis in Britain  

PubMed Central

Field experiments were made in southern England to re-examine the possibility that mosquitoes in Britain might feed on wild rabbits and hence be vectors of myxomatosis. Mosquitoes of several species were attracted to rabbits enclosed in cylindrical traps and in a trap in which the animal was placed in a wire mesh cage. Substantial numbers of mosquitoes were also caught biting, or attempting to bite, tethered rabbits which were not in cages or traps. Evidence that mosquitoes fed on wild rabbits under natural conditions was obtained from results of precipitin tests made on blood-smears collected from mosquitoes caught resting amongst vegetation. On a few evenings mosquitoes were seen to be attracted to healthy wild rabbits and apparently attempting to feed on them. Batches of two mosquito species collected from the field were infected with myxoma virus. It was concluded that contrary to previous beliefs mosquitoes in Britain feed to a certain extent on wild rabbits, and therefore are potential vectors of myxomatosis. No attempts were made to assess their relative importance in the transmission of the disease, which in Britain is transmitted mainly by the rabbit flea. ImagesPlate 1 PMID:4401995

Service, M. W.

1971-01-01

202

Evolutionary and dispersal history of Triatoma infestans, main vector of Chagas disease, by chromosomal markers.  

PubMed

Chagas disease, one of the most important vector-borne diseases in the Americas, is caused by Trypanosoma cruzi and transmitted to humans by insects of the subfamily Triatominae. An effective control of this disease depends on elimination of vectors through spraying with insecticides. Genetic research can help insect control programs by identifying and characterizing vector populations. In southern Latin America, Triatoma infestans is the main vector and presents two distinct lineages, known as Andean and non-Andean chromosomal groups, that are highly differentiated by the amount of heterochromatin and genome size. Analyses with nuclear and mitochondrial sequences are not conclusive about resolving the origin and spread of T. infestans. The present paper includes the analyses of karyotypes, heterochromatin distribution and chromosomal mapping of the major ribosomal cluster (45S rDNA) to specimens throughout the distribution range of this species, including pyrethroid-resistant populations. A total of 417 specimens from seven different countries were analyzed. We show an unusual wide rDNA variability related to number and chromosomal position of the ribosomal genes, never before reported in species with holocentric chromosomes. Considering the chromosomal groups previously described, the ribosomal patterns are associated with a particular geographic distribution. Our results reveal that the differentiation process between both T. infestans chromosomal groups has involved significant genomic reorganization of essential coding sequences, besides the changes in heterochromatin and genomic size previously reported. The chromosomal markers also allowed us to detect the existence of a hybrid zone occupied by individuals derived from crosses between both chromosomal groups. Our genetic studies support the hypothesis of an Andean origin for T. infestans, and suggest that pyrethroid-resistant populations from the Argentinean-Bolivian border are most likely the result of recent secondary contact between both lineages. We suggest that vector control programs should make a greater effort in the entomological surveillance of those regions with both chromosomal groups to avoid rapid emergence of resistant individuals. PMID:25017654

Panzera, Francisco; Ferreiro, Mara J; Pita, Sebastin; Calleros, Luca; Prez, Ruben; Basmadjin, Yester; Guevara, Yenny; Brenire, Simone Frdrique; Panzera, Yanina

2014-10-01

203

Aedes Mosquito Saliva Modulates Rift Valley Fever Virus Pathogenicity  

E-print Network

Aedes Mosquito Saliva Modulates Rift Valley Fever Virus Pathogenicity Alain Le Coupanec1 , Divya) is a severe mosquito-borne disease affecting humans and domestic ruminants. Mosquito saliva contains compounds responses may facilitate virus infection. Indeed, Aedes mosquito saliva played a crucial role in the vector

Boyer, Edmond

204

Mosquito Control  

MedlinePLUS

... Us Mosquito Control About Mosquitoes General Information Life Cycle Information on West Nile Virus--Centers for Disease ... and Toxics Sustainable Practices Water Laws & Regulations By Business Sector By Topic Compliance Enforcement Laws and Executive ...

205

Impact of environment on mosquito response to pyrethroid insecticides: facts, evidences and prospects.  

PubMed

By transmitting major human diseases such as malaria, dengue fever and filariasis, mosquito species represent a serious threat worldwide in terms of public health, and pose a significant economic burden for the African continent and developing tropical regions. Most vector control programmes aiming at controlling life-threatening mosquitoes rely on the use of chemical insecticides, mainly belonging to the pyrethroid class. However, resistance of mosquito populations to pyrethroids is increasing at a dramatic rate, threatening the efficacy of control programmes throughout insecticide-treated areas, where mosquito-borne diseases are still prevalent. In the absence of new insecticides and efficient alternative vector control methods, resistance management strategies are therefore critical, but these require a deep understanding of adaptive mechanisms underlying resistance. Although insecticide resistance mechanisms are intensively studied in mosquitoes, such adaptation is often considered as the unique result of the selection pressure caused by insecticides used for vector control. Indeed, additional environmental parameters, such as insecticides/pesticides usage in agriculture, the presence of anthropogenic or natural xenobiotics, and biotic interactions between vectors and other organisms, may affect both the overall mosquito responses to pyrethroids and the selection of resistance mechanisms. In this context, the present work aims at updating current knowledge on pyrethroid resistance mechanisms in mosquitoes and compiling available data, often from different research fields, on the impact of the environment on mosquito response to pyrethroids. Key environmental factors, such as the presence of urban or agricultural pollutants and biotic interactions between mosquitoes and their microbiome are discussed, and research perspectives to fill in knowledge gaps are suggested. PMID:23123179

Nkya, Theresia Estomih; Akhouayri, Idir; Kisinza, William; David, Jean-Philippe

2013-04-01

206

Novel tests for rapid detection of insecticide resistance in mosquito vectors. Final report, 15 June 1985-31 January 1989  

SciTech Connect

This project is concerned with the formulation of novel diagnostic tests for the detection of organophosphate (OP) resistance in individual mosquitoes. Emphasis was placed on the mechanisms of detoxification by esterases and of insensitive acetycholinesterase. Seven diagnostic tests have resulted from this research to date. Five concern esterases, and two insensitive acetylcholinesterase. An eighth procedure concerns the qualification of proteins in single insects and is used in conjunction with other tests to account for variations in the size of the test insect. Three of the tests developed for esterases (FP/Est, NC/Est and MT/Est) utilize the ability of these enzymes to hydrolyze naphthyl acetate, and two (Dot-Blot/Est and ELISA/Est) involve immunological reactions. The tests for insensitive acetylcholinesterase (NC/AChE and MT/AChE) utilize the differences in inhibitory properties of insecticides on insensitive and normal enzymes.

Georghiou, G.P.

1989-01-31

207

Larvicidal potential of wild mustard (Cleome viscosa) and gokhru (Tribulus terrestris) against mosquito vectors in the semi-arid region of Western Rajasthan.  

PubMed

Cleome viscosa L. (Family: Capparaceae) commonly known as Tickweed or wild mustard and Tribulus terrestris L. (Family: Zygophyllaceae) commonly known as Gokhru, growing wildly in the desert areas in the monsoon and post monsoon season, are of great medicinal importance. Comparative larvicidal efficacy of the extracts from seeds of C. viscosa and fruits and leaves of T. terrestris was evaluated against 3rd or early 4th stage larvae of Anopheles stephensi (Liston), Aedes aegypti (Linnaeus) and Culex quinquefasciatus (Say) in different organic solvents. 24 and 48 hr LC50 and LC90 values along with their 95% fiducial limits, regression equation, chi-square (chi2)/ heterogeneity of the response was determined by log probit regression analysis. The 24 hr LC50 values as determined for seeds of C. viscosa were 144.1, 99.5 and 127.1 (methanol); 106.3, 138.9 and 118.5 (acetone) and 166.4, 162.5 and 301.9 mg l(-1) (petroleum ether extracts) for all the three mosquito species respectively showing that methanol and acetone extracts were a little bit more effective than the petroleum ether extracts. Experiments were carried out with fruits and leaves of T. terrestris with all the solvents and mosquito species. The 24 hr LC50 values, as determined for fruits of T. terrestris were 70.8, 103.4 and 268.2 (methanol); 74.0,120.5 and 132.0 (acetone) and 73.8,113.5 and 137.4 mg l(-1) (petroleum ether extracts) while the 24 hr LC50 values for leaves were 124.3, 196.8 and 246.5 (methanol); 163.4, 196.9 and 224.3 (acetone) and 135.8, 176.8 and 185.9 mg l(-1) (petroleum ether extracts) for all the three mosquito species respectively. The results clearly indicate that fruit extracts of T. terrestris were more effective as compared to leaves extracts in the three solvents tested. Larvae of An. stephensi were found more sensitive to both fruit and leaves extracts of T. terrestris followed by larvae of Ae. aegypti and Cx. quinquefasciatus. Extracts from the seeds of C. viscosa were found less effective as compared to the fruit extracts of T. terrestris indicating that active larvicidal principle may be present in the fruits of this plant species. The studywould be of great importance while formulating the control strategy, for vectors of malaria, dengue and lymphatic filariasis, based on alternative plant based insecticides in this semi-arid region. PMID:24665757

Bansal, S K; Singh, Karam V; Sharma, Sapna

2014-03-01

208

Participatory mapping of target areas to enable operational larval source management to suppress malaria vector mosquitoes in Dar es Salaam, Tanzania  

PubMed Central

Background Half of the population of Africa will soon live in towns and cities where it can be protected from malaria by controlling aquatic stages of mosquitoes. Rigorous but affordable and scaleable methods for mapping and managing mosquito habitats are required to enable effective larval control in urban Africa. Methods A simple community-based mapping procedure that requires no electronic devices in the field was developed to facilitate routine larval surveillance in Dar es Salaam, Tanzania. The mapping procedure included (1) community-based development of sketch maps and (2) verification of sketch maps through technical teams using laminated aerial photographs in the field which were later digitized and analysed using Geographical Information Systems (GIS). Results Three urban wards of Dar es Salaam were comprehensively mapped, covering an area of 16.8 km2. Over thirty percent of this area were not included in preliminary community-based sketch mapping, mostly because they were areas that do not appear on local government residential lists. The use of aerial photographs and basic GIS allowed rapid identification and inclusion of these key areas, as well as more equal distribution of the workload of malaria control field staff. Conclusion The procedure developed enables complete coverage of targeted areas with larval control through comprehensive spatial coverage with community-derived sketch maps. The procedure is practical, affordable, and requires minimal technical skills. This approach can be readily integrated into malaria vector control programmes, scaled up to towns and cities all over Tanzania and adapted to urban settings elsewhere in Africa. PMID:17784963

Dongus, Stefan; Nyika, Dickson; Kannady, Khadija; Mtasiwa, Deo; Mshinda, Hassan; Fillinger, Ulrike; Drescher, Axel W; Tanner, Marcel; Castro, Marcia C; Killeen, Gerry F

2007-01-01

209

Synthesis, depletion and cell-type expression of a protein from the male accessory glands of the dengue vector mosquito Aedes aegypti.  

PubMed

Aedes aegypti males transfer sperm and seminal fluid proteins (Sfps), primarily produced by male accessory glands (AGs), to females during mating. When collectively injected or transplanted into females, AG tissues and/or seminal fluid homogenates have profound effects on Aedes female physiology and behavior. To identify targets and design new strategies for vector control, it is important to understand the biology of the AGs. Thus, we examined characteristics of AG secretion and development in A. aegypti, using the AG-specific seminal fluid protein, AAEL010824, as a marker. We showed that AAEL010824 is first detectable by 12h post-eclosion, and increases in amount over the first 3 days of adult life. We then showed that the amount of AAEL0010824 in the AG decreases after mating, with each successive mating depleting it further; by 5 successive matings with no time for recovery, its levels are very low. AAEL010824 levels in a depleted male are replenished by 48 h post-mating. In addition to examining the level of AAEL010824 protein, we also characterized the expression of its gene. We did this by making a transgenic mosquito line that carries an Enhanced Green Fluorescence Protein (EGFP) fused to the AAEL0010824 promoter that we defined here. We showed that AAEL010824 is expressed in the anterior cells of the accessory glands, and that its RNA levels also respond to mating. In addition to further characterizing AAEL010824 expression, our results with the EGFP fusion provide a promoter for driving AG expression. By providing this information on the biology of an important male reproductive tissue and the production of one of its seminal proteins, our results lay the foundation for future work aimed at identifying novel targets for mosquito population control. PMID:25107876

Alfonso-Parra, Catalina; Avila, Frank W; Deewatthanawong, Prasit; Sirot, Laura K; Wolfner, Mariana F; Harrington, Laura C

2014-11-01

210

Larval occurrence, oviposition behavior and biting activity of potential mosquito vectors of dengue on Samui Island, Thailand  

Microsoft Academic Search

A 1995 outbreak of dengue haemorrhagic fever (DHF) occurred on Samui Island in Thailand with an incidence of almost 500 cases\\/100,000 population. To find and develop effective strategies to control this disease through cost-effective vector control programs, entomological studies were carried out on the island between 1996 and 1998. There were two species of DHF vectors, Aedes aegypti and Ae.

Usavadee Thavara; Apiwat Tawatsin; Chitti Chansang; Wichai Kong-ngamsuk; Supol Paosriwong; Jotika Boon-Long; Yupa Rongsriyam; Narumon Komalamisra

211

166 Journal of Vector Ecology June2008 Colonization of abandoned swimming pools by larval mosquitoes and their  

E-print Network

166 Journal of Vector Ecology June2008 Colonization of abandoned swimming pools by larval.S.A. Received 6 July 2007; Accepted 20 January 2008 ABSTRACT: Thousands of flooded swimming pools were abandoned are abandoned swimming pools that are not maintained during therecoveryandrestorationofurbanlandscapes.Abandoned

Jordan, Frank

212

New Zealand's northern mosquito survey, 1988-89.  

PubMed

The latest mosquito survey of the warmer regions of New Zealand (NZ) sampled 2,304 larval mosquito habitats of all major categories. While revealing no evidence of new establishments of exotic mosquitoes, it produced important data revealing the underutilization of types of habitats that could be invaded now or in the future (especially if the "greenhouse effect" eventually causes even quite small rises in average temperatures and sea levels). Although long feared additions of malaria vectors to a fauna still lacking any species of Anopheles, or of essentially tropical arbovirus vectors from neighboring countries to the north and northeast, may not materialize failing climatic amelioration, a new danger appeared at the beginning of the 1988-89 Northern Mosquito Survey when Aedes albopictus was reported for the first time from Fiji. This vector of dengue hemorrhagic fever and Ross River virus has since been spreading widely on the archipelago's main island, Viti Levu, whence much air and sea traffic reaches NZ. Information presented and discussed herein strongly supports the continuance and improvement of international aircraft disinsection and other insect quarantine measures. PMID:1973449

Laird, M

1990-06-01

213

Contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to UV-A.  

PubMed

Mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. Because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. Numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. Mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure. This ecological feature may affect the general physiology of the insect, including the resistance status against insecticides. In the context of their contrasted breeding sites, we assessed the impact of low-energetic ultraviolet exposure on mosquito sensitivity to biological and chemical insecticides. We show that several mosquito detoxification enzyme activities (cytochrome P450, glutathione S-transferases, esterases) were increased upon low-energy UV-A exposure. Additionally, five specific genes encoding detoxification enzymes (CYP6BB2, CYP6Z7, CYP6Z8, GSTD4, and GSTE2) previously shown to be involved in resistance to chemical insecticides were found over-transcribed in UV-A exposed mosquitoes, revealed by RT-qPCR experiments. More importantly, toxicological bioassays revealed that UV-exposed mosquitoes were more tolerant to four main chemical insecticide classes (DDT, imidacloprid, permethrin, temephos), whereas the bioinsecticide Bacillus thuringiensis subsp. israelensis (Bti) appeared more toxic. The present article provides the first experimental evidence of the capacity of low-energy UV-A to increase mosquito tolerance to major chemical insecticides. This is also the first time that a metabolic resistance to chemical insecticides is linked to a higher susceptibility to a bioinsecticide. These results support the use of Bti as an efficient alternative to chemical insecticides when a metabolic resistance to chemicals has been developed by mosquitoes. PMID:23911355

Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frdric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Raveton, Muriel; Reynaud, Stphane

2013-09-15

214

Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro. Are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?  

PubMed Central

Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex) pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07%) and five of Ae. albopictus (0.18%) were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats. PMID:20140379

Mocellin, Mrcio Goulart; Simes, Taynna Csar; do Nascimento, Teresa Fernandes Silva; Teixeira, Maria Lucia Frana; Lounibos, Leon Philip; de Oliveira, Ricardo Loureno

2012-01-01

215

Alboserpin, a Factor Xa Inhibitor from the Mosquito Vector of Yellow Fever, Binds Heparin and Membrane Phospholipids and Exhibits Antithrombotic Activity*  

PubMed Central

The molecular mechanism of factor Xa (FXa) inhibition by Alboserpin, the major salivary gland anticoagulant from the mosquito and yellow fever vector Aedes albopictus, has been characterized. cDNA of Alboserpin predicts a 45-kDa protein that belongs to the serpin family of protease inhibitors. Recombinant Alboserpin displays stoichiometric, competitive, reversible and tight binding to FXa (picomolar range). Binding is highly specific and is not detectable for FX, catalytic site-blocked FXa, thrombin, and 12 other enzymes. Alboserpin displays high affinity binding to heparin (KD ? 20 nm), but no change in FXa inhibition was observed in the presence of the cofactor, implying that bridging mechanisms did not take place. Notably, Alboserpin was also found to interact with phosphatidylcholine and phosphatidylethanolamine but not with phosphatidylserine. Further, annexin V (in the absence of Ca2+) or heparin outcompetes Alboserpin for binding to phospholipid vesicles, suggesting a common binding site. Consistent with its activity, Alboserpin blocks prothrombinase activity and increases both prothrombin time and activated partial thromboplastin time in vitro or ex vivo. Furthermore, Alboserpin prevents thrombus formation provoked by ferric chloride injury of the carotid artery and increases bleeding in a dose-dependent manner. Alboserpin emerges as an atypical serpin that targets FXa and displays unique phospholipid specificity. It conceivably uses heparin and phosphatidylcholine/phosphatidylethanolamine as anchors to increase protein localization and effective concentration at sites of injury, cell activation, or inflammation. PMID:21673107

Calvo, Eric; Mizurini, Daniella M.; S-Nunes, Anderson; Ribeiro, Jos M. C.; Andersen, John F.; Mans, Ben J.; Monteiro, Robson Q.; Kotsyfakis, Michail; Francischetti, Ivo M. B.

2011-01-01

216

Chemical composition and larvicidal activity of Blumea densiflora essential oils against Anopheles anthropophagus : a malarial vector mosquito  

Microsoft Academic Search

Blumea densiflora, an edible and medicinal plant, is chiefly distributed in Southeast Asia and South Asia. Essential oils extracted by steam\\u000a distillation from B. densiflora were investigated for their chemical composition and larvicidal activity against Anopheles anthropophagus, the primary vector of malaria in China and other East Asian countries. Totally, 46 compounds were identified by gas chromatography\\u000a and mass spectroscopy.

Liang Zhu; Yingjuan Tian

217

A review of recent knowledge of the ecology of the main vectors of trypanosomiasis*  

PubMed Central

In this survey of recent ecological research on the main vectors of trypanosomiasis in those countries of East, Central and West Africa that are not predominantly French-speaking, the authors, after outlining the distribution of tsetse flies and the type of country in which they occur, discuss the direct and indirect effects of climate on these insectsparticularly on their physiological water balance and on pupal fat reservesand their recent advances into new areas. They review the considerable work that has been done on the resting habits and breeding-sites of different Glossina species, knowledge of which is important for effective control, and research on predators of pupae and adult flies and on the feeding activity of tsetse flies. Means of assessing populations and various factors affecting the size and nutritional status of tsetse flies are also discussed, as is the effect on the fly population of artificial changes in the habitat. Finally, a plea is made for a revision of present methods of land use and stock management, if full advantage is to be taken of achievements in fly control. PMID:13928678

Langridge, W. P.; Kernaghan, R. J.; Glover, P. E.

1963-01-01

218

IDENTIFICATION OF CANDIDATE ATTRACTANT COMPOUNDS FROM CHICKEN FEATHERS FOR THE MOSQUITO VECTOR OF THE WEST NILE VIRUS BY GC/MS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquitoes are the primary source of many diseases, including yellow fever, malaria, dengue fever, encephalitis and West Nile Virus (WNV). Because the WNV is maintained in nature by the bird-mosquito-bird cycle, identification of odors emitted from avian hosts will aid in the development of better t...

219

SOURCE REDUCTION BEHAVIOR AS AN INDEPENDENT MEASUREMENT OF THE IMPACT OF A PUBLIC HEALTH EDUCATION CAMPAIGN IN AN INTEGRATED VECTOR MANAGEMENT PROGRAM FOR THE ASIAN TIGER MOSQUITO  

Technology Transfer Automated Retrieval System (TEKTRAN)

The goal of this study was to evaluate the effectiveness of a public health educational campaign to reduce backyard mosquito-larval habitats. Three communities each, within two New Jersey counties, were randomly selected to receive (1) both education and mosquito control, (2) education only, and (3)...

220

Review: Improving our knowledge of male mosquito biology in relation to genetic control programmes.  

PubMed

The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors. The successful production and release of sterile males, which is the mechanism of population suppression by SIT, relies on the release of mass-reared sterile males able to confer sterility in the target population by mating with wild females. A five year Joint FAO/IAEA Coordinated Research Project brought together researchers from around the world to investigate the pre-mating conditions of male mosquitoes (physiology and behaviour, resource acquisition and allocation, and dispersal), the mosquito mating systems and the contribution of molecular or chemical approaches to the understanding of male mosquito mating behaviour. A summary of the existing knowledge and the main novel findings of this group is reviewed here, and further presented in the reviews and research articles that form this Acta Tropica special issue. PMID:24252487

Lees, Rosemary Susan; Knols, Bart; Bellini, Romeo; Benedict, Mark Q; Bheecarry, Ambicadutt; Bossin, Herv Christophe; Chadee, Dave D; Charlwood, Jacques; Dabir, Roch K; Djogbenou, Luc; Egyir-Yawson, Alexander; Gato, Ren; Gouagna, Louis Clment; Hassan, Mo'awia Mukhtar; Khan, Shakil Ahmed; Koekemoer, Lizette L; Lemperiere, Guy; Manoukis, Nicholas C; Mozuraitis, Raimondas; Pitts, R Jason; Simard, Frederic; Gilles, Jeremie R L

2014-04-01

221

Molecular epidemiology of Japanese encephalitis virus in mosquitoes in Taiwan during 2005-2012.  

PubMed

Japanese encephalitis (JE) is a mosquito-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). Pigs and water birds are the main amplifying and maintenance hosts of the virus. In this study, we conducted a JEV survey in mosquitoes captured in pig farms and water bird wetland habitats in Taiwan during 2005 to 2012. A total of 102,633 mosquitoes were collected. Culex tritaeniorhynchus was the most common mosquito species found in the pig farms and wetlands. Among the 26 mosquito species collected, 11 tested positive for JEV by RT-PCR, including Cx. tritaeniorhynchus, Cx. annulus, Anopheles sinensis, Armigeres subalbatus, and Cx. fuscocephala. Among those testing positive, Cx. tritaeniorhynchus was the predominant vector species for the transmission of JEV genotypes I and III in Taiwan. The JEV infection rate was significantly higher in the mosquitoes from the pig farms than those from the wetlands. A phylogenetic analysis of the JEV envelope gene sequences isolated from the captured mosquitoes demonstrated that the predominant JEV genotype has shifted from genotype III to genotype I (GI), providing evidence for transmission cycle maintenance and multiple introductions of the GI strains in Taiwan during 2008 to 2012. This study demonstrates the intense JEV transmission activity in Taiwan, highlights the importance of JE vaccination for controlling the epidemic, and provides valuable information for the assessment of the vaccine's efficacy. PMID:25275652

Su, Chien-Ling; Yang, Cheng-Fen; Teng, Hwa-Jen; Lu, Liang-Chen; Lin, Cheo; Tsai, Kun-Hsien; Chen, Yu-Yu; Chen, Li-Yu; Chang, Shu-Fen; Shu, Pei-Yun

2014-10-01

222

Hidden Sylvatic Foci of the Main Vector of Chagas Disease Triatoma infestans: Threats to the Vector Elimination Campaign?  

PubMed Central

Background Establishing the sources of reinfestation after residual insecticide spraying is crucial for vector elimination programs. Triatoma infestans, traditionally considered to be limited to domestic or peridomestic (abbreviated as D/PD) habitats throughout most of its range, is the target of an elimination program that has achieved limited success in the Gran Chaco region in South America. Methodology/Principal Findings During a two-year period we conducted semi-annual searches for triatomine bugs in every D/PD site and surrounding sylvatic habitats after full-coverage spraying of pyrethroid insecticides of all houses in a well-defined rural area in northwestern Argentina. We found six low-density sylvatic foci with 24 T. infestans in fallen or standing trees located 1102,300 m from the nearest house or infested D/PD site detected after insecticide spraying, when house infestations were rare. Analysis of two mitochondrial gene fragments of 20 sylvatic specimens confirmed their species identity as T. infestans and showed that their composite haplotypes were the same as or closely related to D/PD haplotypes. Population studies with 10 polymorphic microsatellite loci and wing geometric morphometry consistently indicated the occurrence of unrestricted gene flow between local D/PD and sylvatic populations. Mitochondrial DNA and microsatellite sibship analyses in the most abundant sylvatic colony revealed descendents from five different females. Spatial analysis showed a significant association between two sylvatic foci and the nearest D/PD bug population found before insecticide spraying. Conclusions Our study shows that, despite of its high degree of domesticity, T. infestans has sylvatic colonies with normal chromatic characters (not melanic morphs) highly connected to D/PD conspecifics in the Argentinean Chaco. Sylvatic habitats may provide a transient or permanent refuge after control interventions, and function as sources for D/PD reinfestation. The occurrence of sylvatic foci of T. infestans in the Gran Chaco may pose additional threats to ongoing vector elimination efforts. PMID:22039559

Schachter-Broide, Judith; Dujardin, Jean-Pierre; Dotson, Ellen M.; Kitron, Uriel; Grtler, Ricardo E.

2011-01-01

223

Bifenthrin: A Useful Pyrethroid Insecticide for Treatment of Mosquito Nets  

Microsoft Academic Search

Bifenthrin, a pyrethroid insecticide already used in agriculture was evaluated in lab- oratory conditions against susceptible and pyrethroid resistant mosquitoes, as a potential insecticide for treatment of mosquito nets. Two laboratory strains of Anopheles gambiae s.s. Giles, the major malaria vector in Africa, and two of Culex quinquefasciatus Say, a major pest mosquito in urban areas, were used. Compared with

J.-M. HOUGARD; S. Duchon; M. Zaim; P. Guillet

2002-01-01

224

Odor-mediated behavior of afrotropical malaria mosquitoes  

Microsoft Academic Search

The African mosquito species Anopheles gambiaesensu lato s.l. and Anophe- les funestus rank among the world's most efficient vectors of human malaria. Their unique bionomics, particularly their anthropophilic, endophagic and en- dophilic characters, guarantee a strong mosquito-host interaction, favorable to malaria transmission. Olfactory cues govern the various behaviors of female mosquitoes and here we review the role of semiochemicals in

Willem Takken; Bart G. J. Knols

1999-01-01

225

Susceptibility of mosquitoes to ingested insecticides.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquitoes are important vectors of many diseases of medical and veterinary importance. Control of adult mosquitoes is conventionally through application of aerial sprays, however, there are environmental and health concerns associated with these sprays. One approach for targeted control of mosqui...

226

Feeding Patterns of Potential West Nile Virus Vectors in South-West Spain  

PubMed Central

Background Mosquito feeding behaviour determines the degree of vectorhost contact and may have a serious impact on the risk of West Nile virus (WNV) epidemics. Feeding behaviour also interacts with other biotic and abiotic factors that affect virus amplification and transmission. Methodology/Principal Findings We identified the origin of blood meals in five mosquito species from three different wetlands in SW Spain. All mosquito species analysed fed with different frequencies on birds, mammals and reptiles. Both mosquito species and locality explained a similar amount of variance in the occurrence of avian blood meals. However, season of year was the main factor explaining the presence of human blood meals. The differences in diet resulted in a marked spatial heterogeneity in the estimated WNV transmission risk. Culex perexiguus, Cx. modestus and Cx. pipiens were the main mosquito species involved in WNV enzootic circulation since they feed mainly on birds, were abundant in a number of localities and had high vector competence. Cx. perexiguus may also be important for WNV transmission to horses, as are Cx. pipiens and Cx. theileri in transmission to humans. Estimates of the WNV transmission risk based on mosquito diet, abundance and vector competence matched the results of previous WNV monitoring programs in the area. Our sensitivity analyses suggested that mosquito diet, followed by mosquito abundance and vector competence, are all relevant factors in understanding virus amplification and transmission risk in the studied wild ecosystems. At some of the studied localities, the risk of enzootic circulation of WNV was relatively high, even if the risk of transmission to humans and horses was less. Conclusions/Significance Our results describe for first time the role of five WNV candidate vectors in SW Spain. Interspecific and local differences in mosquito diet composition has an important effect on the potential transmission risk of WNV to birds, horses and humans. PMID:22745781

Muoz, Joaqun; Ruiz, Santiago; Soriguer, Ramn; Alcaide, Miguel; Viana, Duarte S.; Roiz, David; Vzquez, Ana; Figuerola, Jordi

2012-01-01

227

A NEW SPECIES OF HEPATOZOON (APICOMPLEXA: ADELEORINA) FROM PYTHON REGIUS (SERPENTES: PYTHONIDAE) AND ITS EXPERIMENTAL TRANSMISSION BY A MOSQUITO VECTOR  

Microsoft Academic Search

Hepatozoon ayorgbor n. sp. is described from specimens of Python regius imported from Ghana. Gametocytes were found in the peripheral blood of 43 of 55 snakes examined. Localization of gametocytes was mainly inside the erythrocytes; free gametocytes were found in 15 (34.9%) positive specimens. Infections of laboratory-reared Culex quinquefasciatus feeding on infected snakes, as well as experimental infection of juvenile

Michal Sloboda; Martin Kamler; Jana Bulantov; Jan Votpka; David Modr

2007-01-01

228

Assessing the optimal virulence of malaria?targeting mosquito pathogens: a mathematical study of engineered Metarhizium anisopliae  

PubMed Central

Background Metarhizium anisopliae is a naturally occurring fungal pathogen of mosquitoes. Recently, Metarhizium has been engineered to act against malaria by directly killing the disease agent within mosquito vectors and also effectively blocking onward transmission. It has been proposed that efforts should be made to minimize the virulence of the fungal pathogen, in order to slow the development of resistant mosquitoes following an actual deployment. Results Two mathematical models were developed and analysed to examine the efficacy of the fungal pathogen. It was found that, in many plausible scenarios, the best effects are achieved with a reduced or minimal pathogen virulence, even if the likelihood of resistance to the fungus is negligible. The results for both models depend on the interplay between two main effects: the ability of the fungus to reduce the mosquito population, and the ability of fungus?infected mosquitoes to compete for resources with non?fungus?infected mosquitoes. Conclusions The results indicate that there is no obvious choice of virulence for engineered Metarhizium or similar pathogens, and that all available information regarding the population ecology of the combined mosquito?fungus system should be carefully considered. The models provide a basic framework for examination of anti?malarial mosquito pathogens that should be extended and improved as new laboratory and field data become available. PMID:24397503

2014-01-01

229

Larvicidal activity of neem and karanja oil cakes against mosquito vectors, Culex quinquefasciatus (say), Aedes aegypti (L.) and Anopheles stephensi (L.).  

PubMed

Larvicidal effect of neem (Azadirachta indica) and karanja (Pongamia glabra) oil cakes (individuals and combination) was studied against mosquito species. Both the oil cakes showed larvicidal activity against the mosquito species tested. The combination of neem and karanja oil cakes in equal proportion proved to have better effect than the individual treatments. The combination of the two oil cakes recorded an LC95 of 0.93, 0.54 and 0.77% against the mosquitoes, Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi respectively The increase in efficacy of the combination treatment over individuals in all the mosquito larvae tested was found to range about 4 to 10 fold in terms of LC50 and 2 to 6 fold in terms of LC95. PMID:18831329

Shanmugasundaram, R; Jeyalakshmi, T; Dutt, M Sunil; Murthy, P Balakrishna

2008-01-01

230

A New Flavivirus and a New Vector: Characterization of a Novel Flavivirus Isolated from Uranotaenia Mosquitoes from a Tropical Rain Forest  

Microsoft Academic Search

Received 5 January 2009\\/Accepted 9 February 2009 A novel flavivirus was isolated from Uranotaenia mashonaensis, a mosquito genus not previously known to harbor flaviviruses. Mosquitoes were caught in the primary rain forest of the TaiNational Park, Cote d'Ivoire. The novel virus, termed nounanevirus (NOUV), seemed to grow only on C6\\/36 insect cells and not on vertebrate cells. Typical enveloped flavivirus-like

Sandra Junglen; Anne Kopp; Andreas Kurth; Georg Pauli; Heinz Ellerbrok; Fabian H. Leendertz

2009-01-01

231

Impact of dryland salinity on population dynamics of vector mosquitoes (Diptera: Culicidae) of Ross River virus in inland areas of southwestern Western Australia.  

PubMed

Clearing of native vegetation for agriculture since European settlement has left 1.047 million ha of southwestern Australia affected by a severe form of environmental degradation called dryland salinity, characterized by secondary soil salinization and waterlogging. This area may expand by a further 1.7-3.4 million ha if current trends continue. Detailed investigations of seasonal of adult and larval mosquito population dynamics were undertaken in the region to test the hypothesis that the development of dryland salinity and waterlogging in inland southwestern Australia has led to a succession of mosquito species and increased Ross River virus (family Togaviridae, genus Alphavirus, RRV) transmission risk. Aedes (Ochlerotatus) camptorhynchus (Thomson) made up >90% of adult mosquito collections in saline regions. Nonmetric multidimensional scaling and generalized estimating equations modeling demonstrated that it was strongly associated with increasing severity of dryland salinity. This article describes the first detailed investigation of the mosquito fauna of inland southwestern Australia, and it is the first description of the influence of secondary soil salinity on mosquito population dynamics. Despite the dominant presence of Ae. camptorhynchus, RRV disease incidence is not currently a significant population health priority in areas affected by dryland salinity. Potential limiting factors include local climatic impacts on the seasonal mosquito population dynamics, vertebrate host distribution and feeding behavior of Ae. camptorhynchus, and the scarce and uneven distribution of the human population in the region. PMID:19058624

Jardine, A; Lindsay, M D A; Johansen, C A; Cook, A; Weinstein, P

2008-11-01

232

Identification of Wolbachia Strains in Mosquito Disease Jewelna Osei-Poku1  

E-print Network

Identification of Wolbachia Strains in Mosquito Disease Vectors Jewelna Osei-Poku1 *, Calvin Han1 Wolbachia-infected mosquitoes could prevent the transmission of arboviruses and other human parasites. We disease transmission rates of infected mosquito species, and could be transferred into other mosquito

Jiggins, Francis

233

Mosquito Habitat and Dengue Risk Potential in Hawaii: A Conceptual Framework and GIS Application  

Microsoft Academic Search

Dengue is an emerging disease, and the distribution of the mosquito vector is partially mediated by environmental conditions. In this article, a new conceptual model is suggested that emphasizes the importance of including environmental variability in mosquito modeling studies. In an applied sense, mosquito habitat maps are developed for Hawaii using a GIS overlay of mosquito survival thresholds of temperature,

Korine N. Kolivras

2006-01-01

234

Free flight of the mosquito Aedes aegypti  

E-print Network

High speed video observations of free flying male Aedes aegypti mosquitoes, the dengue and yellow fever vector, along with custom measurement methods, enable measurement of wingbeat frequency, body position and body orientation of mosquitoes during flight. We find these mosquitoes flap their wings at approximately 850 Hz. We also generate body yaw, body pitch and wing deviation measurements with standard deviations of less than 1 degree and find that sideways velocity and acceleration are important components of mosquito motion. Rapid turns involving changes in flight direction often involve large sideways accelerations. These do not correspond to commensurate changes in body heading, and the insect's flight direction and body heading are decoupled during flight. These findings call in to question the role of yaw control in mosquito flight. In addition, using orientation data, we find that sideways accelerations are well explained by roll-based rotation of the lift vector. In contrast, the insect's body pitch...

Iams, S M

2012-01-01

235

Understanding the effect of vector dynamics in epidemic models using center manifold analysis  

NASA Astrophysics Data System (ADS)

In vector borne diseases the human hosts' epidemiology often acts on a much slower time scales than the one of the mosquitos which transmit the disease as a vector from human to human, due to their vastly different life cycles. We investigate in a model with susceptible (S), infected (I) and recovered (R) humans and susceptible (U) and infected (V) mosquitoes in how far the fast time scale of the mosquito epidemiology can be slaved by the slower human epidemiology, so that for the understanding of human disease data mainly the dynamics of the human time scale is essential and only slightly perturbed by the mosquito dynamics. This analysis of the SIRUV model is qualitatively in agreement with a previously investigated simpler SISUV model, hence a feature of vector-borne diseases in general.

Rocha, Filipe; Aguiar, Mara; Souza, Max; Stollenwerk, Nico

2012-09-01

236

Finding the Right Plugin: Mosquitoes Have the Answer Tracey Chapman*  

E-print Network

on the identification of seminal fluid proteins in the mosquito vectors of dengue/yellow fever and of malaria [15 injection in the yellow fever vector Aedes aegypti is also reported to affect flight (e.g., [23]), responses

Nachman, Michael

237

Insect Repellents: Modulators of mosquito odorant receptor activity  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquitoes vector numerous pathogens that cause diseases including malaria, yellow fever, dengue fever and chikungunya. DEET, IR3535, Picaridin and 2-undecanone are insect repellents that are used to prevent interactions between humans and a broad array of disease vectors including mosquitoes. While...

238

COPI-mediated blood meal digestion in vector mosquitoes is independent of midgut ARF-GEF and ARF-GAP regulatory activities  

PubMed Central

We have previously shown that defects in COPI coatomer proteins cause 80% mortality in blood fed Aedes aegypti mosquitoes by 96 hr post-feeding. In this study we show that similar deficiencies in COPII and clathrin mediated vesicle transport do not disrupt blood meal digestion and are not lethal, even though both COPII and clathrin functions are required for ovarian development. Since COPI vesicle transport is controlled in mammalian cells by upstream G proteins and associated regulatory factors, we investigated the function of the orthologous ADP-ribosylation factor 1 (ARF1) and ARF4 proteins in mosquito tissues. We found that both ARF1 and ARF4 function upstream of COPI vesicle transport in blood fed mosquitoes given that an ARF1/ARF4 double deficiency is required to phenocopy the feeding-induced mortality observed in COPI coatomer deficient mosquitoes. Small molecule inhibitors of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) are often transitory, and therefore, we investigated the role of five Ae. aegypti ARF-GEF and ARF-GAP proteins in blood meal digestion using RNA interference. Surprisingly, we found that ARF-GEF and ARF-GAP functions are not required for blood meal digestion, even though both vitellogenesis and ovarian development in Ae. aegypti are dependent on GBF1 (ARF-GEF) and GAP1/GAP2 (ARF-GAPs) proteins. Moreover, deficiencies in orthologous COPI regulating genes in Anopheles stephensi mosquitoes had similar phenotypes, indicating conserved functions in these two mosquito species. We propose that based on the need for rapid initiation of protein digestion and peritrophic membrane formation, COPI vesicle transport in midgut epithelial cells is not dependent on ARF-GEF and ARF-GAP regulatory proteins to mediate vesicle recycling within the first 48 hr post-feeding. PMID:23727611

Isoe, Jun; Stover, Weston; Miesfeld, R. Barrett; Miesfeld, Roger L.

2013-01-01

239

COPI-mediated blood meal digestion in vector mosquitoes is independent of midgut ARF-GEF and ARF-GAP regulatory activities.  

PubMed

We have previously shown that defects in COPI coatomer proteins cause 80% mortality in blood fed Aedes aegypti mosquitoes by 96 h post-feeding. In this study we show that similar deficiencies in COPII and clathrin mediated vesicle transport do not disrupt blood meal digestion and are not lethal, even though both COPII and clathrin functions are required for ovarian development. Since COPI vesicle transport is controlled in mammalian cells by upstream G proteins and associated regulatory factors, we investigated the function of the orthologous ADP-ribosylation factor 1 (ARF1) and ARF4 proteins in mosquito tissues. We found that both ARF1 and ARF4 function upstream of COPI vesicle transport in blood fed mosquitoes given that an ARF1/ARF4 double deficiency is required to phenocopy the feeding-induced mortality observed in COPI coatomer deficient mosquitoes. Small molecule inhibitors of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) are often transitory, and therefore, we investigated the role of five Ae. aegypti ARF-GEF and ARF-GAP proteins in blood meal digestion using RNA interference. Surprisingly, we found that ARF-GEF and ARF-GAP functions are not required for blood meal digestion, even though both vitellogenesis and ovarian development in Ae. aegypti are dependent on GBF1 (ARF-GEF) and GAP1/GAP2 (ARF-GAPs) proteins. Moreover, deficiencies in orthologous COPI regulating genes in Anopheles stephensi mosquitoes had similar phenotypes, indicating conserved functions in these two mosquito species. We propose that based on the need for rapid initiation of protein digestion and peritrophic membrane formation, COPI vesicle transport in midgut epithelial cells is not dependent on ARF-GEF and ARF-GAP regulatory proteins to mediate vesicle recycling within the first 48 h post-feeding. PMID:23727611

Isoe, Jun; Stover, Weston; Miesfeld, R Barrett; Miesfeld, Roger L

2013-08-01

240

Evaluation of attractive toxic sugar bait (ATSB)-Barrier for control of vector and nuisance mosquitoes and its effect on non-target organisms in sub-tropical environments in Florida.  

PubMed

The efficacy of attractive toxic sugar baits (ATSB) with the active ingredient eugenol, an Environmental Protection Agency exempt compound, was evaluated against vector and nuisance mosquitoes in both laboratory and field studies. In the laboratory, eugenol combined in attractive sugar bait (ASB) solution provided high levels of mortality for Aedes aegypti, Culex quinquefasciatus, and Anopheles quadrimaculatus. Field studies demonstrated significant control: >70% reduction for Aedes atlanticus, Aedes. infirmatus, and Culex nigripalpus and >50% reduction for Anopheles crucians, Uranotaenia sapphirina, Culiseta melanura, and Culex erraticus three weeks post ATSB application. Furthermore, non-target feeding of six insect orders, Hymenoptera, Lepidoptera, Coleoptera, Diptera, Hemiptera, and Orthoptera, was evaluated in the field after application of a dyed-ASB to flowering and non-flowering vegetation. ASB feeding (staining) was determined by dissecting the guts and searching for food dye with a dissecting microscope. The potential impact of ATSB on non-targets, applied on green non-flowering vegetation was low for all non-target groups (0.9%). However, application of the ASB to flowering vegetation resulted in significant staining of the non-target insect orders. This highlights the need for application guidelines to reduce non-target effects. No mortality was observed in laboratory studies with predatory non-targets, spiders, praying mantis, or ground beetles, after feeding for three days on mosquitoes engorged on ATSB. Overall, our laboratory and field studies support the use of eugenol as an active ingredient for controlling important vector and nuisance mosquitoes when used as an ATSB toxin. This is the first study demonstrating effective control of anophelines in non-arid environments which suggest that even in highly competitive sugar rich environments this method could be used for control of malaria in Latin American countries. PMID:24361724

Qualls, Whitney A; Mller, Gnter C; Revay, Edita E; Allan, Sandra A; Arheart, Kristopher L; Beier, John C; Smith, Michal L; Scott, Jodi M; Kravchenko, Vasiliy D; Hausmann, Axel; Yefremova, Zoya A; Xue, Rui-De

2014-03-01

241

Vectors  

NSDL National Science Digital Library

This lesson was created by Larry Friesen and Anne Gillis for Butler Community College. It will help physics and calculus students differentiate between the uses of vectors in mathematics vs. physics. This website provides two PDF documents that give detailed lessons about vectors, including an overview of terminology, sample problems, and an HTML worksheet is also provided. For educators or students, this site offers well laid-out lessons and/or practice with vectors.

Friesen, Larry; Gillis, Anne

2008-04-18

242

The main sceneries of Chagas disease transmission. The vectors, blood and oral transmissions - A comprehensive review.  

PubMed

This review deals with transmission of Trypanosoma cruzi by the most important domestic vectors, blood transfusion and oral intake. Among the vectors, Triatoma infestans, Panstrongylus megistus, Rhodnius prolixus, Triatoma dimidiata, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma sordida, Triatoma maculata, Panstrongylus geniculatus, Rhodnius ecuadoriensis and Rhodnius pallescens can be highlighted. Transmission of Chagas infection, which has been brought under control in some countries in South and Central America, remains a great challenge, particularly considering that many endemic countries do not have control over blood donors. Even more concerning is the case of non-endemic countries that receive thousands of migrants from endemic areas that carry Chagas disease, such as the United States of America, in North America, Spain, in Europe, Japan, in Asia, and Australia, in Oceania. In the Brazilian Amazon Region, since Shaw et al. (1969) described the first acute cases of the disease caused by oral transmission, hundreds of acute cases of the disease due to oral transmission have been described in that region, which is today considered to be endemic for oral transmission. Several other outbreaks of acute Chagas disease by oral transmission have been described in different states of Brazil and in other South American countries. PMID:25466622

Coura, Jos Rodrigues

2014-12-01

243

Oviposition strategies of temporary pool mosquitoes in relation to weather, tidal regime and land use in a temperate wetland.  

PubMed

Wetlands have traditionally been associated with harbouring mosquitoes, a well-known nuisance and vectors of diseases. Within mosquito life cycle, oviposition is a determinant event by shaping their individual fitness and vectorial capacity. The study was conducted in one of the main temperate wetlands in South America. We used Generalized Linear Models to study the relation between temperature, precipitation, tidal regime, land use, microenvironment, and the occurrence of floodwater (Ochlerotatus and Psorophora spp.) and raft-laying (Culex and Uranotaenia spp.) mosquitoes using temporary pools as larval habitats. Pool occurrence was negatively associated with temperature, and positively related to precipitation and high tides. As regards the land use, it was lowest in domestic areas and plantations, intermediate in secondary forests, and highest in marshes. Each oviposition strategy was best modelled as a function of different environmental factors. The occurrence of floodwater mosquitoes was positively associated with high cumulative precipitation and low tide records. Raft-laying mosquitoes were related to low temperature records, while the effect of flooding varied with the land use. In view of these results, physical (water inputs and movement), chemical, and biological (egg and larval flushing, and predatory interactions) considerations are given to provide insight in the oviposition patterns of mosquitoes occurring in this complex wetland. We finally propose the generation of a tidal flow as a control measure against floodwater mosquitoes, which are the most anthropophilic in the study area. PMID:22647341

Cardo, M V; Vezzani, D; Carbajo, A E

2012-12-01

244

Wolbachia-a foe for mosquitoes  

PubMed Central

Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.

Guruprasad, Nadipinayakanahalli Munikrishnappa; Jalali, Sushil Kumar; Puttaraju, Hosagavi Puttegowda

2014-01-01

245

Plant extracts as potential mosquito larvicides.  

PubMed

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-05-01

246

An automated GIS/remotely sensed early warning system to detect elevated populations of vectors of Rift Valley fever, a mosquito-borne emerging virus threat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquito transmitted infectious diseases, like eastern equine encephalitis (EEE), Rift Valley fever (RVF), and West Nile virus (WNV), pose an international threat to animal and human health. An introduction of RVF into the U.S. would severely impact wild ungulate populations and the beef and dairy ...

247

Insights into host-finding by Culex mosquitoes: New tools for surveillance?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Culex mosquitoes are important vectors of pathogens and parasites causing diseases such as West Nile virus, St. Louis encephalitis, Japanese encephalitis, Venezuelan equine encephalitis and bancroftian filariasis. Surveillance of these species is based on traps using conventional mosquito attractan...

248

Entomological study on transmission of avian malaria parasites in a zoological garden in Japan: bloodmeal identification and detection of avian malaria parasite DNA from blood-fed mosquitoes.  

PubMed

Several species of captive and wild birds have been found to be infected with various avian blood protozoa in Japan. We investigated the prevalence and transmission of avian malaria parasite and determined the bloodmeal hosts of mosquitoes collected in a zoological garden in Tokyo, Japan, by using the polymerase chain reaction. In total, 310 unfed and 140 blood-fed mosquitoes of seven species were collected by using sweep nets and CDC traps. Bloodmeal identification indicated that mosquitoes had fed on 17 avian and five mammalian species, including captive animals. The results of avian malaria parasite detection from mosquitoes with avian bloodmeals indicated that Culex pipiens pallens Coquillet is a main vector of avian Plasmodium in the current study site and that some captive and wild birds could be infected with avian malaria parasites. Furthermore, the distances between the collection site of blood-fed mosquitoes and the locations of their blood-source captive animals were estimated. Most females with fresh bloodmeals were found within 40 m of caged animals, whereas half-gravid and gravid females were found between 10 and 350 m from caged host animals. We demonstrated that blood-fed mosquitoes can provide useful information regarding the mosquito vector species of avian malaria parasites and allows for noninvasive detection of the presence of avian malaria parasites in bird populations. PMID:21661321

Ejiri, Hiroko; Sato, Yukita; Kim, Kyeong-Soon; Hara, Tatsuko; Tsuda, Yoshio; Imura, Takayuki; Murata, Koichi; Yukawa, Masayoshi

2011-05-01

249

North American wetlands and mosquito control.  

PubMed

Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

Rey, Jorge R; Walton, William E; Wolfe, Roger J; Connelly, C Roxanne; O'Connell, Sheila M; Berg, Joe; Sakolsky-Hoopes, Gabrielle E; Laderman, Aimlee D

2012-12-01

250

Vectors  

NSDL National Science Digital Library

This web page introduces vectors as an extension of numbers having both magnitude and direction. The initial motivation is to describe velocity but the material includes a general discussion of vector algebra and an application to forces for the inclined plane. The page contains links to a related lesson plan and further opportunities to explore vectors. This is part of the extensive web site "From Stargazers to Starships", that uses space exploration and space science to introduce topics in physics and astronomy. Translations in Spanish and French are available.

Stern, David

2006-07-16

251

Replication of Clone 13, a naturally attenuated avirulent isolate of Rift Valley fever virus, in Aedes and Culex mosquitoes.  

PubMed

Rift Valley fever virus continues to cause large outbreaks of acute and febrile illness among humans and domestic animals in Africa. The high pathogenicity of the virus is mainly due to the non-structural protein derived from the S segment NSs, which was shown to inhibit the type I interferon expression at the transcriptional level and to suppress host cell RNA synthesis. Clone 13, a naturally attenuated clone containing a deletion of 70% in NSs, is a promising vaccine candidate as it has no pathogenicity for mice and is highly immunogenic leading to long-lasting immunity. If Clone 13 succeeds in inducing a transient viremia in inoculated animals, is a mosquito vector able to replicate Clone 13 and is the vector affected by viral infection? In this work, we orally infected two mosquito species, Aedes vexans and Culex pipiens quinquefasciatus, with the avirulent Clone 13. We showed that the mosquito Ae. vexans better replicated the avirulent Clone 13 than Cx. p. quinquefasciatus. Moreover, infection with Clone 13 did not cause any important changes in mosquito's life-history traits compared to noninfected females. Nevertheless, it is likely that Clone 13 would not be efficiently transmitted by mosquito vectors. PMID:20854021

Moutailler, Sara; Krida, Ghazi; Madec, Yoann; Bouloy, Michle; Failloux, Anna-Bella

2010-10-01

252

Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control  

PubMed Central

Background Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on area-wide integrated pest management (AW-IPM) that may include the sterile insect technique (SIT). To support the planning and implementation of future AW-IPM activities, larval surveys were carried out to provide key data on spatial and seasonal dynamics of local vector populations. Methods Monthly cross-sectional larval surveys were carried out between March 2005 and May 2007 in two localities (Dongola and Merowe) adjacent to the river Nile. A stratified random sampling strategy based on the use of Remote Sensing (RS), Geographical Information Systems (GIS) and the Global Positioning System (GPS) was used to select survey locations. Breeding sites were mapped using GPS and data on larval density and breeding site characteristics were recorded using handheld computers. Bivariate and multivariate logistic regression models were used to identify breeding site characteristics associated with increased risk of presence of larvae. Seasonal patterns in the proportion of breeding sites positive for larvae were compared visually to contemporaneous data on climate and river height. Results Of a total of 3,349 aquatic habitats sampled, 321 (9.6%) contained An. arabiensis larvae. The frequency with which larvae were found varied markedly by habitat type. Although most positive sites were associated with temporary standing water around the margins of the main Nile channel, larvae were also found at brickworks and in areas of leaking pipes and canals often far from the river. Close to the Nile channel, a distinct seasonal pattern in larval populations was evident and appeared to be linked to the rise and fall of the river level. These patterns were not evident in vector populations breeding in artificial water sources away from the river. Conclusion The GIS-based survey strategy developed in this study provides key data on the population dynamics of An. arabiensis in Northern State. Quantitative estimates of the contributions of various habitat types and their proximity to settlements provide a basis for planning a strategy for reducing malaria risk by elimination of the vector population. PMID:19500425

Ageep, Tellal B; Cox, Jonathan; Hassan, M'oawia M; Knols, Bart GJ; Benedict, Mark Q; Malcolm, Colin A; Babiker, Ahmed; El Sayed, Badria B

2009-01-01

253

Human to Mosquito Transmission of Dengue Viruses  

PubMed Central

The successful transmission of dengue virus from a human host to a mosquito vector requires a complex set of factors to align. It is becoming increasingly important to improve our understanding of the parameters that shape the human to mosquito component of the transmission cycle so that vaccines and therapeutic antivirals can be fully evaluated and epidemiological models refined. Here we describe these factors, and discuss the biological and environmental impacts and demographic changes that are influencing these dynamics. Specifically, we examine features of the human infection required for the mosquito to acquire the virus via natural blood feeding, as well as the biological and environmental factors that influence a mosquitos susceptibility to infection, up to the point that they are capable of transmitting the virus to a new host. PMID:24987394

Carrington, Lauren B.; Simmons, Cameron P.

2014-01-01

254

Evolution of mosquito preference for humans linked to an odorant receptor.  

PubMed

Female mosquitoes are major vectors of human disease and the most dangerous are those that preferentially bite humans. A 'domestic' form of the mosquito Aedes aegypti has evolved to specialize in biting humans and is the main worldwide vector of dengue, yellow fever, and chikungunya viruses. The domestic form coexists with an ancestral, 'forest' form that prefers to bite non-human animals and is found along the coast of Kenya. We collected the two forms, established laboratory colonies, and document striking divergence in preference for human versus non-human animal odour. We further show that the evolution of preference for human odour in domestic mosquitoes is tightly linked to increases in the expression and ligand-sensitivity of the odorant receptor AaegOr4, which we found recognizes a compound present at high levels in human odour. Our results provide a rare example of a gene contributing to behavioural evolution and provide insight into how disease-vectoring mosquitoes came to specialize on humans. PMID:25391959

McBride, Carolyn S; Baier, Felix; Omondi, Aman B; Spitzer, Sarabeth A; Lutomiah, Joel; Sang, Rosemary; Ignell, Rickard; Vosshall, Leslie B

2014-11-13

255

Physico-chemical and biological characterization of anopheline mosquito larval habitats (Diptera: Culicidae): implications for malaria control  

PubMed Central

Background A fundamental understanding of the spatial distribution and ecology of mosquito larvae is essential for effective vector control intervention strategies. In this study, data-driven decision tree models, generalized linear models and ordination analysis were used to identify the most important biotic and abiotic factors that affect the occurrence and abundance of mosquito larvae in Southwest Ethiopia. Methods In total, 220 samples were taken at 180 sampling locations during the years 2010 and 2012. Sampling sites were characterized based on physical, chemical and biological attributes. The predictive performance of decision tree models was evaluated based on correctly classified instances (CCI), Cohens kappa statistic (?) and the determination coefficient (R2). A conditional analysis was performed on the regression tree models to test the relation between key environmental and biological parameters and the abundance of mosquito larvae. Results The decision tree model developed for anopheline larvae showed a good model performance (CCI?=?84??2%, and ??=?0.66??0.04), indicating that the genus has clear habitat requirements. Anopheline mosquito larvae showed a widespread distribution and especially occurred in small human-made aquatic habitats. Water temperature, canopy cover, emergent vegetation cover, and presence of predators and competitors were found to be the main variables determining the abundance and distribution of anopheline larvae. In contrast, anopheline mosquito larvae were found to be less prominently present in permanent larval habitats. This could be attributed to the high abundance and diversity of natural predators and competitors suppressing the mosquito population densities. Conclusions The findings of this study suggest that targeting smaller human-made aquatic habitats could result in effective larval control of anopheline mosquitoes in the study area. Controlling the occurrence of mosquito larvae via drainage of permanent wetlands may not be a good management strategy as it negatively affects the occurrence and abundance of mosquito predators and competitors and promotes an increase in anopheline population densities. PMID:24499518

2013-01-01

256

Diversity and function of bacterial microbiota in the mosquito holobiont  

PubMed Central

Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is considered in the context of possible extended phenotypes conferred on the insect hosts that allow niche diversification and rapid adaptive evolution in other insects. These kinds of observations have prompted the recent development of new mosquito control methods based on the use of symbiotically-modified mosquitoes to interfere with pathogen transmission or reduce the host life span and reproduction. New opportunities for exploiting bacterial function for vector control are highlighted. PMID:23688194

2013-01-01

257

Molecular identification of bloodmeals from sand flies and mosquitoes collected in Israel.  

PubMed

In Israel, sand flies are the vectors of Leishmania Ross and mosquitoes are the vectors of West Nile Virus. In the Judean Desert and Tiberias, the sand fly Phlebotomus sergenti Parrot is the vector of Leishmania tropica (Wright) and the rock hyrax (Procavia capensis Pallas) is considered the main reservoir animal. The main vectors of West Nile Virus are Culex pipiens L. and Culex perexiguus Theobald. Bloodmeals of engorged field-caught female sand flies and mosquitoes are an important source for defining host preferences. Recent progress in DNA molecular techniques has enabled the accurate identification of blood sources within the arthropod gut. In this study, we applied molecular approach for species-specific identification based on polymerase chain reaction and nucleotide sequence analysis of polymorphic regions along two mitochondrial genes, 12S and 16S rRNA. The research was carried out on 261 engorged female sand flies collected in the Judean Desert and Tiberias and 50 engorged female mosquitoes collected in Tel-Aviv and Arava. Species identification of bloodmeals was successful in 92% of the samples. Rock hyrax was the most abundant host in bloodmeals of P. sergenti, while human blood was found in only seven (3%) females. L. tropica DNA was detected in three P. sergenti females from Tiberias that contained rock hyrax blood. Avian sequences were detected in 67% (10 of 15) of the identified bloodmeals from Cx. perexiguus and in 10% (3 of 29) of the identified meals from Cx. pipiens. Human sequences were found in 14% of the identified bloodmeals from Cx. pipiens. The successful analysis of the majority of the bloodmeals performed on wild sand flies and mosquitoes suggests that bloodmeal identification can be applied as one of the routine procedures in vector surveillance programs. PMID:24897862

Valinsky, Lea; Ettinger, Gonen; Bar-Gal, Gila Kahila; Orshan, Laor

2014-05-01

258

Mapping the main Leishmania phlebotomine vector in the endemic focus of the Mt. Vesuvius in southern Italy.  

PubMed

Geographical information systems and remote sensing were used to analyze the distribution of the Leishmania infantum-Phlebotomus perniciosus parasite-vector system in relation to environmental features of two opposite sides (coastal and Apennine) of Mt. Vesuvius, an area of intense transmission of human and canine leishmaniasis in southern Italy. Weekly phlebotomine collections were carried out during two consecutive warm seasons (2004- 2005) in 24 and 25 sites of the coastal and Apennine sides, respectively. Sandflies were caught using over one-thousand and seven hundred 20 x 20 cm-sticky traps placed in different environments. A total of 873 sandflies were collected, of which 284 (32.5%) were identified as P. perniciosus. The cumulative density (number of specimens/m2 of sticky trap/two nights) of this vector species was 3.9. P. perniciosus was significantly more abundant in the coastal side (5.8) as compared to the Apennine side (1.4). The main environmental differences between the two sides were the aspect (south-west for the coastal and north-east for the Apennine side) and land use. The predominance of green vegetated environments (forest, semi-natural and agricultural areas) in the coastal side, in contrast with the predominance of artificial surfaces (namely urban environment) in the Apennine side, could be responsible for the different P. perniciosus densities between the two surveyed areas. PMID:18686244

Rossi, Erika; Rinaldi, Laura; Musella, Vincenzo; Veneziano, Vincenzo; Carbone, Sabrina; Gradoni, Luigi; Cringoli, Giuseppe; Maroli, Michele

2007-05-01

259

Larval ecology of mosquitoes in sylvatic arbovirus foci in southeastern Senegal  

PubMed Central

Background Although adult mosquito vectors of sylvatic arbovirus [yellow fever (YFV), dengue-2 (DENV-2) and chikungunya (CHIKV)] have been studied for the past 40 years in southeastern Senegal, data are still lacking on the ecology of larval mosquitoes in this area. In this study, we investigated the larval habitats of mosquitoes and characterized their seasonal and spatial dynamics in arbovirus foci. Methods We searched for wet microhabitats, classified in 9 categories, in five land cover classes (agriculture, forest, savannah, barren and village) from June, 2010 to January, 2011. Mosquito immatures were sampled monthly in up to 30 microhabitats of each category per land cover and bred until adult stage for determination. Results No wet microhabitats were found in the agricultural sites; in the remaining land covers immature stages of 35 mosquito species in 7 genera were sampled from 9 microhabitats (tree holes, fresh fruit husks, decaying fruit husks, puddles, bamboo holes, discarded containers, tires, rock holes and storage containers). The most abundant species was Aedes aegypti formosus, representing 30.2% of the collections, followed by 12 species, representing each more than 1% of the total, among them the arbovirus vectors Ae. vittatus (7.9%), Ae. luteocephalus (5.7%), Ae. taylori (5.0%), and Ae. furcifer (1.3%). Aedes aegypti, Cx. nebulosus, Cx. perfuscus, Cx. tritaeniorhynchus, Er. chrysogster and Ae. vittatus were the only common species collected from all land covers. Aedes furcifer and Ae. taylori were collected in fresh fruit husks and tree holes. Species richness and dominance varied significantly in land covers and microhabitats. Positive associations were found mainly between Ae. furcifer, Ae. taylori and Ae. luteocephalus. A high proportion of potential enzootic vectors that are not anthropophilic were found in the larval mosquito fauna. Conclusions In southeastern Senegal, Ae. furcifer and Ae. taylori larvae showed a more limited distribution among both land cover and microhabitat types than the other common species. Uniquely among vector species, Ae. aegypti formosus larvae occurred at the highest frequency in villages. Finally, a high proportion of the potential non-anthropophilic vectors were represented in the larval mosquito fauna, suggesting the existence of unidentified sylvatic arbovirus cycles in southeastern Senegal. PMID:23216815

2012-01-01

260

The Role of Innate Immunity in Conditioning Mosquito Susceptibility to West Nile Virus  

PubMed Central

Arthropod-borne viruses (arboviruses) represent an emerging threat to human and livestock health globally. In particular, those transmitted by mosquitoes present the greatest challenges to disease control efforts. An understanding of the molecular basis for mosquito innate immunity to arbovirus infection is therefore critical to investigations regarding arbovirus evolution, virus-vector ecology, and mosquito vector competence. In this review, we discuss the current state of understanding regarding mosquito innate immunity to West Nile virus. We draw from the literature with respect to other virus-vector pairings to attempt to draw inferences to gaps in our knowledge about West Nile virus and relevant vectors. PMID:24351797

Prasad, Abhishek N.; Brackney, Doug. E.; Ebel, Gregory D.

2013-01-01

261

Sampling Host-Seeking Anthropophilic Mosquito Vectors in West Africa: Comparisons of An Active Human-Baited Tent-Trap against Gold Standard Methods.  

PubMed

In this study, we characterize the ability of the previously described Infoscitex tent (IST) to capture mosquitoes in comparison to either the Centers for Disease Control Light Trap hung next to individuals under a bed net (LTC) or to human landing catches (HLC). In Senegal, the IST caught 6.14 times the number of Anopheles gambiae sensu lato (s.l.), and 8.78 times the Culex group V mosquitoes as LTC. In one of two locations in Burkina Faso, the IST caught An. gambiae at a rate not significantly different than HLC. Of importance, 9.1-36.1% of HLC caught An. gambiae were blood fed, mostly with fresh blood, suggesting they fed upon the collector, whereas only 0.5-5.0% from the IST had partial or old blood. The IST also caught outdoor biting species in proportions comparable to HLC. The results show this tent provides a safer and effective alternative to the skill-dependent, risky, and laborious HLC method. PMID:25422393

Krajacich, Benjamin J; Slade, Jeremiah R; Mulligan, Robert F; LaBrecque, Brendan; Alout, Haoues; Grubaugh, Nathan D; Meyers, Jacob I; Fakoli, Lawrence S; Bolay, Fatorma K; Brackney, Doug E; Burton, Timothy A; Seaman, Jonathan A; Diclaro, Joseph W; Dabir, Roch K; Foy, Brian D

2014-11-24

262

Genetic control of Aedes mosquitoes  

PubMed Central

Aedes mosquitoes include important vector species such as Aedes aegypti, the major vector of dengue. Genetic control methods are being developed for several of these species, stimulated by an urgent need owing to the poor effectiveness of current methods combined with an increase in chemical pesticide resistance. In this review we discuss the various genetic strategies that have been proposed, their present status, and future prospects. We focus particularly on those methods that are already being tested in the field, including RIDL and Wolbachia-based approaches. PMID:23816508

Alphey, Luke; McKemey, Andrew; Nimmo, Derric; Neira Oviedo, Marco; Lacroix, Renaud; Matzen, Kelly; Beech, Camilla

2013-01-01

263

A Quantitative Study of Gene Regulation Involved in the Immune Response of Anopheline Mosquitoes  

E-print Network

A Quantitative Study of Gene Regulation Involved in the Immune Response of Anopheline Mosquitoes Plasmodium falciparum and the mosquito vector 1 Anopheles. Of particular interest is the molecular biology. This paper reports a statistical analysis of gene expression time profiles from mosquitoes which have been

Holmes, Chris

264

Feasible Introgression of an Anti-pathogen Transgene into an Urban Mosquito Population without Using  

E-print Network

Feasible Introgression of an Anti-pathogen Transgene into an Urban Mosquito Population without, much attention now focuses instead on transgenic strategies aimed at mosquito population suppression, an approach generally perceived to be practical. By contrast, aiming to replace vector competent mosquito

Lloyd, Alun

265

Drought-induced mosquito outbreaks in wetlands Jonathan M. Chase1  

E-print Network

REPORT Drought-induced mosquito outbreaks in wetlands Jonathan M. Chase1 * and Tiffany M. Knight2 1 Mosquitoes are not only a nuisance, but also vector many important human and animal diseases. Here, in opposition with the dogma that increased precipitation predicts mosquito abundance, we hypothesize

266

EFFECTS OF SINGLE AND MULTIPLE APPLICATIONS OF MOSQUITO INSECTICIDES ON NONTARGET ARTHROPODS  

E-print Network

EFFECTS OF SINGLE AND MULTIPLE APPLICATIONS OF MOSQUITO INSECTICIDES ON NONTARGET ARTHROPODS RYAN S Johnson Hall, Montana State University, Bozeman, MT 59717-3120 ABSTRACT. Mosquito management plans have been implemented in the United States and globally to manage mosquito vectors of West Nile virus

Peterson, Robert K. D.

267

Deposition and Air Concentrations of Permethrin and Naled Used for Adult Mosquito Management  

E-print Network

Deposition and Air Concentrations of Permethrin and Naled Used for Adult Mosquito Management Jerome effective ways of managing adult mosquitoes that vector human and animal pathogens is the use of ultra of the insecticides used for the management of adult mosquitoes, we conducted an environmental fate study after truck

Peterson, Robert K. D.

268

Determination of Allosteric Solvent Effects Between Acetylcholinesterase and Mosquito Selective Carbamates: Implications for High Throughput Screening of Insecticides.  

E-print Network

??Malaria is vectored by the mosquito Anopheles gambiae (Ag) in Sub-Saharan Africa and infects approximately 500 million people annually. The increasing prevalence of pyrethroid-resistant mosquitoes (more)

Swale, Daniel Robert

2010-01-01

269

Countering a Bioterrorist Introduction of Pathogen-Infected Mosquitoes through Mosquito Control  

Technology Transfer Automated Retrieval System (TEKTRAN)

A workshop titled Counteracting Bioterrorist Introduction of Pathogen-Infected Vector Mosquitoes was held in Gainesville, Florida on May 20-22, 2010 to discuss (1) disease and vector surveillance, (2) pre-bioterrorist attack preparations, (3) actions during an ongoing bioterrorist attack, and (4) ...

270

Mosquitocidal and water purification properties of Cynodon dactylon, Aloe vera, Hemidesmus indicus and Coleus amboinicus leaf extracts against the mosquito vectors.  

PubMed

Ethanolic extracts of Cynodon dactylon, Aloe vera, Hemidesmus indicus and Coleus amboinicus were tested for their toxicity effect on the third-instar larvae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The leaves of C. dactylon, A. vera, H. indicus and C. amboinicus were collected from natural habitats (forests) in Western Ghats, Tamil Nadu, India. A total of 250 g of fresh, mature leaves were rinsed with distilled water and dried in shade. The dried leaves were put in Soxhlet apparatus and extract prepared using 100% ethanol for 72 h at 30-40C. Dried residues were obtained from 100 g of extract evaporated to dryness in rotary vacuum evaporator. Larvicidal properties of ethanolic leaf extracts showed that the extracts are effective as mosquito control agents. The larval mortality was observed after 24 h exposure. No mortality was observed in the control. The median lethal concentration (LC(50)) values observed for the larvicidal activities are 0.44%, 0.51%, 0.59% and 0.68% for extracts of C. dactylon, A. vera, H. indicus and C. amboinicus, respectively. The observed mortality were statistically significant at P?mosquito larvae in laboratory and field. The selected plants were shown to exhibit water purification properties. Water quality parameters such as turbidity, pH and water clarity were analyzed in the water samples (pre-treatment and post-treatment of plant extracts) taken from the different breeding sites of mosquitoes. Water colour, turbidity and pH were reduced significantly after treatment with C. dactylon (13 HU, 31.5 mg/l and 6.9), H. indicus (13.8 HU, 33 mg/l and 7.1), A. vera (16 HU, 33.8 mg/l and 7.4) and C. amboinicus (21 HU, 35 mg/l and 7.5) extracts. The study proved that the extracts of C. dactylon, A. vera, H. indicus and C. amboinicus have both mosquitocidal and water sedimentation properties. PMID:21947308

Arjunan, Nareshkumar; Murugan, Kadarkarai; Madhiyazhagan, Pari; Kovendan, Kalimuthu; Prasannakumar, Kanagarajan; Thangamani, Sundaram; Barnard, Donald R

2012-04-01

271

Plant based products: use and development as repellents against mosquitoes: A review.  

PubMed

Global warming and deforestation have resulted in the relocation of many living creatures including insects during the recent years. This has affected the population balance of disease vectors including mosquitoes resulting in outbreaks. Traditionally, mankind has been using plants as means of protection from the mosquitoes which are considered to be environment friendly unlike the synthetic chemicals that cause major risk to human health and the ecosystem. Researchers explored mainly, essential oils and traditional plants using different testing methodologies to find out repellent molecules effective against mosquitoes which is the main focus of this review. Among the promising plant species, Eucalyptus spp., Ocimum spp. and Cymbopogon spp. are the most cited. Data of repellency produced from the bioassay systems is difficult to quantify because of different parameters, testing system and standards of material used against mosquitoes. Mainly, the human forearm based bioassays have been used with different sizes of treatment area in the laboratory and the results have not been tested in the field conditions for residual activity. In addition, effectiveness of essential oils and their protection time can be increased by using vanillin as synergist and formulation techniques like microencapsulation and nanoemulsion. There is a need to develop an alternate in vitro bioassay system that can address the problems of uniformity of the results. PMID:24631763

Rehman, Junaid U; Ali, Abbas; Khan, Ikhlas A

2014-06-01

272

Mosquitoes of Guam and the Northern Marianas: distribution, checklists, and notes on mosquito-borne pathogens.  

PubMed

This report includes the distribution records and updated checklists of the mosquitoes known to occur in Guam and nearby selected islands (ie, Saipan, Tinian, Rota), based on our field collections from various localities during 2010, published reports, and accessioned specimens deposited in the US National Museum of Natural History, Smithsonian Institution, Washington, DC. The status of common and potential mosquito vectors and their borne-pathogens are also noted. PMID:21805452

Rueda, Leopoldo M; Pecor, James E; Reeves, Will K; Wolf, Stephen P; Nunn, Peter V; Rabago, Rosanna Y; Gutierrez, Teresa L; Debboun, Mustapha

2011-01-01

273

Mosquito-borne arboviruses in arctic america.  

PubMed

Mosquito-borne arboviruses are prevalent throughout subarctic regions of Canada and Alaska, principally in the boreal forest extending between latitudes 53 and 66 degrees N, but they have been identified in tundra regions as far north as 70 degrees N. All mosquito-borne agents have been bunyaviruses, comprising principally the snowshoe hare subtype of California encephalitis (CE) virus, but also Northway virus. Mosquito vectors comprise several Aedes species and Culiseta inornata, all of which have supported replication of CE virus following incubation at 13 degrees C or lower temperatures. Isolation of virus from wild-caught larvae points towards transovarial transfer. Principal vertebrate reservoirs of infection are mammals, especially snowshoe hares (Lepus americanus) and ground squirrels (Citellus undulatus). Where the boreal forest merges into prairie grassland around 53 degrees N, Culex tarsalis mosquitoes become prevalent, and an alphavirus, western equine encephalomyelitis, is detected more frequently than CE virus. PMID:1602

Mclean, D M

1975-10-01

274

Old ingredients for a new recipe? Neem cake, a low-cost botanical by-product in the fight against mosquito-borne diseases.  

PubMed

Mosquitoes (Diptera: Culicidae) represent an important threat to millions of people worldwide, since they act as vectors for important pathogens, such as malaria, yellow fever, dengue and West Nile. Control programmes mainly rely on chemical treatments against larvae, indoor residual spraying and insecticide-treated bed nets. In recent years, huge efforts have been carried out to propose new eco-friendly alternatives, with a special focus on the evaluation of plant-borne mosquitocidal compounds. Major examples are neem-based products (Azadirachta indica A. Juss, Meliaceae) that have been proven as really effective against a huge range of pests of medical and veterinary importance, including mosquitoes. Recent research highlighted that neem cake, a cheap by-product from neem oil extraction, is an important source of mosquitocidal metabolites. In this review, we examined (i) the latest achievements about neem cake metabolomics with special reference to nor-terpenoid and related content; (ii) the neem cake ovicidal, larvicidal and pupicidal toxicity against Aedes, Anopheles and Culex mosquito vectors; (iii) its non-target effects against vertebrates; and (iv) its oviposition deterrence effects on mosquito females. Overall, neem cake can be proposed as an eco-friendly and low-cost source of chemicals to build newer and safer control tools against mosquito vectors. PMID:25563612

Benelli, Giovanni; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Madhiyazhagan, Pari; Conti, Barbara; Nicoletti, Marcello

2015-02-01

275

Comparative Genome Analysis of the Yellow Fever Mosquito Aedes aegypti  

E-print Network

Comparative Genome Analysis of the Yellow Fever Mosquito Aedes aegypti with Drosophila melanogaster aegypti, and Culex pipiens, the primary vectors for malaria, yellow fever and dengue, and lymphatic 103

Severson, David

276

Public health significance of invasive mosquitoes in Europe.  

PubMed

There are currently five invasive Aedes mosquito species known to be established in Europe, namely Aedes albopictus, Aedes aegypti, Aedes japonicus, Aedes atropalpus and Aedes koreicus. Aedes albopictus and Aedes aegypti are the incriminated vectors in the recent outbreaks of chikungunya and dengue fever in Europe. However, both laboratory experiments and field observations indicate that these invasive mosquitoes have a potential to also transmit other pathogens of public health importance. Increasing travel and pathogen introduction, expansion of vector distribution, and both environmental and climatic changes are likely to raise the risk of pathogen transmission by these invasive Aedes mosquitoes. Their vector status and their involvement in pathogen transmission are dynamic processes that shape the future of mosquito-borne disease epidemiology in Europe. Beside vector surveillance, enhanced disease surveillance will enable the early detection of cases and the prompt implementation of control measures. PMID:23574618

Schaffner, F; Medlock, J M; Van Bortel, W

2013-08-01

277

A Modified Experimental Hut Design for Studying Responses of Disease-Transmitting Mosquitoes to Indoor Interventions: The Ifakara Experimental Huts  

PubMed Central

Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. However, many of these experimental hut designs have a number of limitations, for example: 1) inability to sample mosquitoes on all sides of huts, 2) increased likelihood of live mosquitoes flying out of the huts, leaving mainly dead ones, 3) difficulties of cleaning the huts when a new insecticide is to be tested, and 4) the generally small size of the experimental huts, which can misrepresent actual local house sizes or airflow dynamics in the local houses. Here, we describe a modified experimental hut design - The Ifakara Experimental Huts- and explain how these huts can be used to more realistically monitor behavioural and physiological responses of wild, free-flying disease-transmitting mosquitoes, including the African malaria vectors of the species complexes Anopheles gambiae and Anopheles funestus, to indoor vector control-technologies including ITNs and IRS. Important characteristics of the Ifakara experimental huts include: 1) interception traps fitted onto eave spaces and windows, 2) use of eave baffles (panels that direct mosquito movement) to control exit of live mosquitoes through the eave spaces, 3) use of replaceable wall panels and ceilings, which allow safe insecticide disposal and reuse of the huts to test different insecticides in successive periods, 4) the kit format of the huts allowing portability and 5) an improved suite of entomological procedures to maximise data quality. PMID:22347415

Okumu, Fredros O.; Moore, Jason; Mbeyela, Edgar; Sherlock, Mark; Sangusangu, Robert; Ligamba, Godfrey; Russell, Tanya; Moore, Sarah J.

2012-01-01

278

Boosting the sterile insect technique to control mosquitoes.  

PubMed

Mosquitoes are vectors of major diseases. Auto-dissemination recently proved very efficient to control Aedes species, using adult females contaminated with dissemination stations of juvenile hormone to treat breeding habitats, but cannot be used at large scales. Here we propose to combine it to the Sterile Insect Technique (SIT) to create a new control concept, named 'boosted SIT' that might enable the area-wide eradication of mosquitoes and many other vectors and insect pests. PMID:24746400

Bouyer, Jrmy; Lefranois, Thierry

2014-06-01

279

Virtual mosquito  

NSDL National Science Digital Library

3D virtual image of a mosquito (Family Culicidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the Help page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

280

Mosquito, adult (image)  

MedlinePLUS

This illustration shows an adult southern house mosquito. This mosquito feeds on blood and is the carrier of many diseases, such as encephalitis, West Nile, dengue fever, yellow fever, and others. ( ...

281

Detection of eastern equine encephalitis virus antibodies in moose (Alces americana), Maine, 2010.  

PubMed

Moose sera were collected from harvested animals during the 2010 hunting season in Maine. Of the 145 serum samples screened by plaque reduction neutralization test (PRNT), 16 (11%) had antibodies to eastern equine encephalitis virus (EEEV). Positive samples were collected from Aroostook County (n=13), Somerset County (n=2), and Piscataquis County (n=1) in northern and central Maine. Preliminary mosquito surveillance revealed the presence of enzootic and bridge vectors mosquitoes, including Culiseta (Climacura) melanura (Coquillett), Aedes (Aedimorphus) vexans (Meigen), and Coquillettidia (Coquillettidia) perturbans (Walker). Select mosquito species were tested by RT-PCR for the presence of EEEV. None were positive. This is the first report of EEEV in moose from Maine. PMID:24359417

Lubelczyk, Charles; Elias, Susan P; Kantar, Lee; Albert, Jennifer; Hansen, Stephen; Saxton-Shaw, Kali; MacMillan, Katharine; Smith, Leticia B; Eisen, Rebecca; Swope, Bethany; Smith, Robert Pease; Mutebi, John-Paul

2014-01-01

282

Susceptibility and irritability of adult forms of main malaria vectors against insecticides used in the indoor residual sprays in Muzaffargarh District, Pakistan: a field survey.  

PubMed

In southern Punjab, Pakistan, Muzaffargarh District is known to have insecticide-resistant Anopheles and drug-resistant Plasmodium spp. In this part of the country, five anopheline mosquitoes, Anopheles stephensi Liston, Anopheles culicifacies Giles, Anopheles fluviatilis James, Anopheles superpictus Grassi, and Anopheles subpictus Grassi (Diptera: Culicidae) are known as malaria vectors. Among these, An. culicifacies is the primary and An. stephensi is the secondary malaria vector. Outbreaks of malaria usually occur after rainy episodes. We conducted field surveys to collect field strains of An. culicifacies and An. stephensi mosquitoes from different areas of Muzaffargarh District. We determined susceptibility and irritability levels of their adult stages to the discriminative dose of different insecticides. For this purpose, we used World Health Organization's established criteria for assessment. Mortality was calculated after 1 h exposure and for 24 h recovery period for various insecticides. An. stephensi was found to be significantly resistant to dichlorodiphenyltrichloroethane (DDT, an organochlorine), dieldrin (a chlorinated hydrocarbon), and malathion (organophosphorus), with lethal times (LT50) of 83.17, 52.48, and 37.53, respectively. However, the species was significantly sensitive to permethrin, deltamethrin (pyrethroids), and fenitrothion (organophosphate) with LT50 of 2.85, 2.34, and 13.18, respectively. Among these, permethrin showed more promising results against adult An. stephensi. When analyzed for irritancy, we found that among pyrethroids, permethrin was the most irritant insecticide for both An. stephensi and An. culicifacies. DDT and dieldrin showed least irritancy with 0.42 +/- 0.08 and 0.77 +/- 0.12 takeoffs per minute per adult, respectively, against An. stephensi. The mean number of takeoffs per minute per adult with permethrin showed significant irritancy for permethrin when compared with DDT. Based on this study, we conclude that the use of organochlorine (DDT) and chlorinated hydrocarbon (dieldrin) should not be reintroduced in Malaria Control Programme in Pakistan until there is enough evidence to do so at any stage in future, and the use of pyrethroids should continue, with preference to permethrin for better control of malariaby indoor residual spraying. PMID:24724288

Rana, Saleem M; Khan, Ejaz A; Yaqoob, Aashifa; Latif, Asma A; Abbasi, Mudassar M

2014-03-01

283

Pesticides and Mosquito Control  

NSDL National Science Digital Library

This factsheet from the Environmental Protection Agency includes several summary documents on the problem of mosquito-borne diseases and the pesticides used to control mosquitoes. The resources cover issues from mosquito biology through the EPA's recent findings on the negative health impacts of Malathion.

284

MAN, MOSQUITOES AND MICROBES.  

ERIC Educational Resources Information Center

THE CONTROL OF MOSQUITOES IS A MATTER OF INCREASING CONCERN IN THE STATE OF FLORIDA. A BRIEF DESCRIPTION OF THE LIFE CYCLE, VARIOUS SPECIES, CONTROL, AND DESCRIPTION OF DISEASES TRANSMITTED BY THE MOSQUITO WAS PRESENTED. THE ARTICLE CONCLUDED THAT MOSQUITO CONTROL IS NOT ONLY A HEALTH PROBLEM, BUT ALSO A MATTER OF IMPROVED ECONOMICS IN RELATION TO

SCHOONOVER, ROBERT A.

285

The Plant Virus Tomato Spotted Wilt Tospovirus Activates the Immune System of Its Main Insect Vector, Frankliniella occidentalis  

Microsoft Academic Search

Tospoviruses have the ability to infect plants and their insect vectors. Tomato spotted wilt virus (TSWV), the type species in the Tospovirus genus, infects its most important insect vector, Frankliniella occidentalis, the western flower thrips (WFT). However, no detrimental effects on the life cycle or cytopathological changes have been reported in the WFT after TSWV infection, and relatively few viral

Ricardo B. Medeiros; Renato de O. Resende; Antonio Carlos de Avila

2004-01-01

286

Natural malaria infection reduces starvation resistance of nutritionally stressed mosquitoes.  

PubMed

In disease ecology, there is growing evidence that environmental quality interacts with parasite and host to determine host susceptibility to an infection. Most studies of malaria parasites have focused on the infection costs incurred by the hosts, and few have investigated the costs on mosquito vectors. The interplay between the environment, the vector and the parasite has therefore mostly been ignored and often relied on unnatural or allopatric Plasmodium/vector associations. Here, we investigated the effects of natural avian malaria infection on both fecundity and survival of field-caught female Culex pipiens mosquitoes, individually maintained in laboratory conditions. We manipulated environmental quality by providing mosquitoes with different concentrations of glucose-feeding solution prior to submitting them to a starvation challenge. We used molecular-based methods to assess mosquitoes' infection status. We found that mosquitoes infected with Plasmodium had lower starvation resistance than uninfected ones only under low nutritional conditions. The effect of nutritional stress varied with time, with the difference of starvation resistance between optimally and suboptimally fed mosquitoes increasing from spring to summer, as shown by a significant interaction between diet treatment and months of capture. Infected and uninfected mosquitoes had similar clutch size, indicating no effect of infection on fecundity. Overall, this study suggests that avian malaria vectors may suffer Plasmodium infection costs in their natural habitat, under certain environmental conditions. This may have major implications for disease transmission in the wild. PMID:24286465

Lalubin, Fabrice; Deldevant, Aline; Glaizot, Olivier; Christe, Philippe

2013-11-29

287

ChAd63-MVAvectored Blood-stage Malaria Vaccines Targeting MSP1 and AMA1: Assessment of Efficacy Against Mosquito Bite Challenge in Humans  

PubMed Central

The induction of cellular immunity, in conjunction with antibodies, may be essential for vaccines to protect against blood-stage infection with the human malaria parasite Plasmodium falciparum. We have shown that prime-boost delivery of P. falciparum blood-stage antigens by chimpanzee adenovirus 63 (ChAd63) followed by the attenuated orthopoxvirus MVA is safe and immunogenic in healthy adults. Here, we report on vaccine efficacy against controlled human malaria infection delivered by mosquito bites. The blood-stage malaria vaccines were administered alone, or together (MSP1+AMA1), or with a pre-erythrocytic malaria vaccine candidate (MSP1+ME-TRAP). In this first human use of coadministered ChAd63-MVA regimes, we demonstrate immune interference whereby responses against merozoite surface protein 1 (MSP1) are dominant over apical membrane antigen 1 (AMA1) and ME-TRAP. We also show that induction of strong cellular immunity against MSP1 and AMA1 is safe, but does not impact on parasite growth rates in the blood. In a subset of vaccinated volunteers, a delay in time to diagnosis was observed and sterilizing protection was observed in one volunteer coimmunized with MSP1+AMA1results consistent with vaccine-induced pre-erythrocytic, rather than blood-stage, immunity. These data call into question the utility of T cell-inducing blood-stage malaria vaccines and suggest that the focus should remain on high-titer antibody induction against susceptible antigen targets. PMID:23089736

Sheehy, Susanne H; Duncan, Christopher JA; Elias, Sean C; Choudhary, Prateek; Biswas, Sumi; Halstead, Fenella D; Collins, Katharine A; Edwards, Nick J; Douglas, Alexander D; Anagnostou, Nicholas A; Ewer, Katie J; Havelock, Tom; Mahungu, Tabitha; Bliss, Carly M; Miura, Kazutoyo; Poulton, Ian D; Lillie, Patrick J; Antrobus, Richard D; Berrie, Eleanor; Moyle, Sarah; Gantlett, Katherine; Colloca, Stefano; Cortese, Riccardo; Long, Carole A; Sinden, Robert E; Gilbert, Sarah C; Lawrie, Alison M; Doherty, Tom; Faust, Saul N; Nicosia, Alfredo; Hill, Adrian VS; Draper, Simon J

2012-01-01

288

Detection of West Nile virus RNA in mosquitoes and identification of mosquito blood meals collected at alligator farms in Louisiana.  

PubMed

Since 2001, alligator farms in the United States have sustained substantial economic losses because of West Nile virus (WNV) outbreaks in American alligators (Alligator mississippiensis). Once an initial infection is introduced into captive alligators, WNV can spread among animals by contaminative transmission. Some outbreaks have been linked to feeding on infected meat or the introduction of infected hatchlings, but the initial source of WNV infection has been uncertain in other outbreaks. We conducted a study to identify species composition and presence of WNV in mosquito populations associated with alligator farms in Louisiana. A second objective of this study was to identify the origin of mosquito blood meals collected at commercial alligator farms. Mosquitoes were collected from 2004 to 2006, using Centers for Disease Control light traps, gravid traps, backpack aspirators, and resting boxes. We collected a total of 58,975 mosquitoes representing 24 species. WNV was detected in 41 pools of females from 11 mosquito species: Anopheles crucians, Anopheles quadrimaculatus, Coquillettidia perturbans, Culex coronator, Culex erraticus, Culex nigripalpus, Culex quinquefasciatus, Mansonia titillans, Aedes sollicitans, Psorophora columbiae, and Uranotaenia lowii. The blood meal origins of 213 field-collected mosquitoes were identified based on cytochrome B sequence identity. Alligator blood was detected in 21 mosquitoes representing six species of mosquitoes, including Cx. quinquefasciatus and Cx. nigripalpus. Our results showed that mosquitoes of species that are known to be competent vectors of WNV fed regularly on captive alligators. Therefore, mosquitoes probably are important in the role of transmission of WNV at alligator farms. PMID:20695278

Unlu, Isik; Kramer, Wayne L; Roy, Alma F; Foil, Lane D

2010-07-01

289

Prevalence of avian malaria parasite in mosquitoes collected at a zoological garden in Japan  

Microsoft Academic Search

Several species of captive birds at zoological gardens of Japan were found to be infected with avian Plasmodium. However, incriminated vector mosquito species have not been identified yet. To indicate the competent vectors of avian malaria\\u000a parasite, we collected mosquitoes at a zoological garden in Japan and examined for the avian malaria parasite DNA. Totally,\\u000a 1,361 mosquitoes of 11 species

Hiroko Ejiri; Yukita Sato; Risa Sawai; Emi Sasaki; Rei Matsumoto; Miya Ueda; Yukiko Higa; Yoshio Tsuda; Sumie Omori; Koichi Murata; Masayoshi Yukawa

2009-01-01

290

Novel flaviviruses from mosquitoes: Mosquito-specific evolutionary lineages within the phylogenetic group of mosquito-borne flaviviruses  

PubMed Central

Novel flaviviruses that are genetically related to pathogenic mosquito-borne flaviviruses (MBFV) have been isolated from mosquitoes in various geographical locations, including Finland. We isolated and characterized another novel virus of this group from Finnish mosquitoes collected in 2007, designated as Ilomantsi virus (ILOV). Unlike the MBFV that infect both vertebrates and mosquitoes, the MBFV-related viruses appear to be specific to mosquitoes similar to the insect-specific flaviviruses (ISFs). In this overview of MBFV-related viruses we conclude that they differ from the ISFs genetically and antigenically. Phylogenetic analyses separated the MBFV-related viruses isolated in Africa, the Middle East and South America from those isolated in Europe and Asia. Serological cross-reactions of MBFV-related viruses with other flaviviruses and their potential for vector-borne transmission require further characterization. The divergent MBFV-related viruses are probably significantly under sampled to date and provide new information on the variety, properties and evolution of vector-borne flaviviruses. PMID:25108382

Huhtamo, Eili; Cook, Shelley; Moureau, Gregory; Uzctegui, Nathalie Y.; Sironen, Tarja; Kuivanen, Suvi; Putkuri, Niina; Kurkela, Satu; Harbach, Ralph E.; Firth, Andrew E.; Vapalahti, Olli; Gould, Ernest A.; de Lamballerie, Xavier

2014-01-01

291

Anopheles plumbeus (Diptera: Culicidae) in Europe: a mere nuisance mosquito or potential malaria  

E-print Network

Anopheles plumbeus (Diptera: Culicidae) in Europe: a mere nuisance mosquito or potential malaria vector? Schaffner et al. Schaffner et al. Malaria Journal 2012, 11:393 http mosquito or potential malaria vector? Francis Schaffner1* , Isabelle Thiéry2 , Christian Kaufmann1 , Agnès

Boyer, Edmond

292

Use of geographic information systems to depict and analyze mosquito population trends.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquitoes transmit (vector) disease agents that cause malaria, yellow fever, dengue, West Nile fever, and encephalitis. Spread of these diseases is controlled by the management of mosquito population levels, changes in which are monitored in vector surveillance programs by the use of mechanical tr...

293

The impact of uniform and mixed species blood meals on the fitness of the mosquito vector Anopheles gambiae s.s: does a specialist pay for diversifying its host species diet?  

PubMed

We investigated the fitness consequences of specialization in an organism whose host choice has an immense impact on human health: the African malaria vector Anopheles gambiae s.s. We tested whether this mosquito's specialism on humans can be attributed to the relative fitness benefits of specialist vs. generalist feeding strategies by contrasting their fecundity and survival on human-only and mixed host diets consisting of blood meals from humans and animals. When given only one blood meal, An.gambiae s.s. survived significantly longer on human and bovine blood, than on canine or avian blood. However, when blood fed repeatedly, there was no evidence that the fitness of An.gambiae s.s. fed a human-only diet was greater than those fed generalist diets. This suggests that the adoption of generalist host feeding strategies in An.gambiae s.s. is not constrained by intraspecific variation in the resource quality of blood from other available host species. PMID:22221693

Lyimo, I N; Keegan, S P; Ranford-Cartwright, L C; Ferguson, H M

2012-03-01

294

Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro--are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?  

PubMed

Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex) pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07%) and five of Ae. albopictus(0.18%) were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats. PMID:20140379

Mocellin, Mrcio Goulart; Simes, Taynna Csar; Nascimento, Teresa Fernandes Silva do; Teixeira, Maria Lucia Frana; Lounibos, Leon Philip; Oliveira, Ricardo Loureno de

2009-12-01

295

The Mosquito Melanization Response Is Implicated in Defense against the Entomopathogenic Fungus Beauveria bassiana  

PubMed Central

Mosquito immunity studies have focused mainly on characterizing immune effector mechanisms elicited against parasites, bacteria and more recently, viruses. However, those elicited against entomopathogenic fungi remain poorly understood, despite the ubiquitous nature of these microorganisms and their unique invasion route that bypasses the midgut epithelium, an important immune tissue and physical barrier. Here, we used the malaria vector Anopheles gambiae as a model to investigate the role of melanization, a potent immune effector mechanism of arthropods, in mosquito defense against the entomopathogenic fungus Beauveria bassiana, using in vivo functional genetic analysis and confocal microscopy. The temporal monitoring of fungal growth in mosquitoes injected with B. bassiana conidia showed that melanin eventually formed on all stages, including conidia, germ tubes and hyphae, except the single cell hyphal bodies. Nevertheless, melanin rarely aborted the growth of any of these stages and the mycelium continued growing despite being melanized. Silencing TEP1 and CLIPA8, key positive regulators of Plasmodium and bacterial melanization in A. gambiae, abolished completely melanin formation on hyphae but not on germinating conidia or germ tubes. The detection of a layer of hemocytes surrounding germinating conidia but not hyphae suggested that melanization of early fungal stages is cell-mediated while that of late stages is a humoral response dependent on TEP1 and CLIPA8. Microscopic analysis revealed specific association of TEP1 with surfaces of hyphae and the requirement of both, TEP1 and CLIPA8, for recruiting phenoloxidase to these surfaces. Finally, fungal proliferation was more rapid in TEP1 and CLIPA8 knockdown mosquitoes which exhibited increased sensitivity to natural B. bassiana infections than controls. In sum, the mosquito melanization response retards significantly B. bassiana growth and dissemination, a finding that may be exploited to design transgenic fungi with more potent bio-control activities against mosquitoes. PMID:23166497

Osta, Mike A.

2012-01-01

296

Reduced survival and reproductive success generates selection pressure for the dengue mosquito Aedes aegypti to evolve resistance against infection by the microsporidian parasite Vavraia culicis  

PubMed Central

The success and sustainability of control measures aimed at reducing the transmission of mosquito-borne diseases will depend on how they influence the fitness of mosquitoes in targeted populations. We investigated the effects of the microsporidian parasite Vavraia culicis on the survival, blood-feeding behaviour and reproductive success of female Aedes aegypti mosquitoes, the main vector of dengue. Infection reduced survival to adulthood and increased adult female mosquito age-dependent mortality relative to uninfected individuals; this additional mortality was closely correlated with the number of parasite spores they harboured when they died. In the first gonotrophic cycle, infected females were less likely to blood-feed, took smaller meals when they did so, and developed fewer eggs than uninfected females. Even though the conditions of this laboratory study favoured minimal developmental times, the costs of infection were already being experienced by the time females reached an age at which they could first reproduce. These results suggest there will be selection pressure for mosquitoes to evolve resistance against this pathogen if it is used as an agent in a control program to reduce the transmission of mosquito-borne human diseases. PMID:24822081

Sy, Victoria E; Agnew, Philip; Sidobre, Christine; Michalakis, Yannis

2014-01-01

297

Dengue Vectors and their Spatial Distribution.  

PubMed

The distribution of dengue vectors, Ae. aegypti and Ae. albopictus, is affected by climatic factors. In addition, since their life cycles are well adapted to the human environment, environmental changes resulting from human activity such as urbanization exert a great impact on vector distribution. The different responses of Ae. aegypti and Ae albopictus to various environments result in a difference in spatial distribution along north-south and urban-rural gradients, and between the indoors and outdoors. In the north-south gradient, climate associated with survival is an important factor in spatial distribution. In the urban-rural gradient, different distribution reflects a difference in adult niches and is modified by geographic and human factors. The direct response of the two species to the environment around houses is related to different spatial distribution indoors and outdoors. Dengue viruses circulate mainly between human and vector mosquitoes, and the vector presence is a limiting factor of transmission. Therefore, spatial distribution of dengue vectors is a significant concern in the epidemiology of the disease.Current technologies such as GIS, satellite imagery and statistical models allow researchers to predict the spatial distribution of vectors in the changing environment. Although it is difficult to confirm the actual effect of environmental and climate changes on vector abundance and vector-borne diseases, environmental changes caused by humans and human behavioral changes due to climate change can be expected to exert an impact on dengue vectors. Longitudinal monitoring of dengue vectors and viruses is therefore necessary. PMID:22500133

Higa, Yukiko

2011-12-01

298

The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre-and Post-Blood Meal  

E-print Network

The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal. PLoS ONE 6(7): e22573. doi@nmsu.edu Introduction The yellow fever mosquito, Aedes aegypti, is the primary vector for dengue fever, several

Houde, Peter

299

Ecology of Larval Mosquitoes, with Special Reference to Anopheles arabiensis (Diptera: Culcidae) in Market-Garden Wells in  

E-print Network

Ecology of Larval Mosquitoes, with Special Reference to Anopheles arabiensis (Diptera: Culcidae-garden wells that provide permanent sites for mosquito larvae, in particular Anopheles arabiensis Patton, the major vector of malaria. A study of the bioecology of mosquito larvae was conducted over 1 yr

Thioulouse, Jean

300

Resistance Status of the Malaria Vector Mosquitoes, Anopheles stephensi and Anopheles subpictus Towards Adulticides and Larvicides in Arid and Semi-Arid Areas of India  

PubMed Central

Susceptibility studies of malaria vectors Anopheles stephensi Liston (Diptera: Culicidae) and An. subpictus Grassi collected during 20042007 from various locations of Arid and Semi-Arid Zone of India were conducted by adulticide bioassay of DDT, malathion, deltamethrin and larvicide bioassay of fenthion, temephos, chlorpyriphos and malathion using diagnostic doses. Both species from all locations exhibited variable resistance to DDT and malathion from majority of location. Adults of both the species were susceptible to Deltamethrin. Larvae of both the Anopheline species showed some evidence of resistance to chlorpyriphos followed by fenthion whereas susceptible to temephos and malathion. PMID:21870971

Tikar, S. N.; Mendki, M.J.; Sharma, A. K.; Sukumaran, D.; Veer, Vijay; Prakash, Shri; Parashar, B. D.

2011-01-01

301

Malaria Mosquitoes Attracted by Fatal Fungus  

PubMed Central

Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

George, Justin; Jenkins, Nina E.; Blanford, Simon; Thomas, Matthew B.; Baker, Thomas C.

2013-01-01

302

Toxicity of saponin isolated from Gymnema sylvestre R. Br. (Asclepiadaceae) against Culex tritaeniorhynchus Giles (Diptera: Culicidae) Japanese encephalitis vector mosquito in India.  

PubMed

To determine the larvicidal activity of various extracts of Gymnema sylvestre against the Japanese Encephalitis vector, Culex tritaeniorynchus in Tamilnadu, India. To identify the active principle present in the promising fraction obtained in Chlorofom:Methanol extract of Fraction 2. The G. sylvestre leaf extracts were tested, employing WHO procedure against fourth instar larvae of C. tritaeniorhynchus and the larval mortalities were recorded at various concentrations (6.25, 12.5, 25.0, 50 and 100 g/mL); the 24h LC50 values of the G. Sylvestre leaf extracts were determined following Probit analysis. It was noteworthy that treatment level 100 g/mL exhibited highest mortality rates for the three different crude extracts and was significantly different from the mean mortalities recorded for the other concentrations. The LC50 values of 34.756 g/mL (24.475-51.41), 31.351 g/mL (20.634-47.043) and 28.577 g/mL (25.159-32.308) were calculated for acetone, chloroform and methanol extract with the chi-square values of 10.301, 31.351 and 4.093 respectively. The present investigation proved that G. Sylvestre could be possibly utilized as an important component in the Vector Control Program. PMID:23152320

Elumalai, Kupppusamy; Dhanasekaran, Shanmugan; Krishnappa, Kaliamoorthy

2012-12-01

303

Conditioning Individual Mosquitoes to an Odor: Sex, Source, and Time  

PubMed Central

Olfactory conditioning of mosquitoes may have important implications for vector-pathogen-host dynamics. If mosquitoes learn about specific host attributes associated with pathogen infection, it may help to explain the heterogeneity of biting and disease patterns observed in the field. Sugar-feeding is a requirement for survival in both male and female mosquitoes. It provides a starting point for learning research in mosquitoes that avoids the confounding factors associated with the observer being a potential blood-host and has the capability to address certain areas of close-range mosquito learning behavior that have not previously been described. This study was designed to investigate the ability of the southern house mosquito, Culex quinquefasciatus Say to associate odor with a sugar-meal with emphasis on important experimental considerations of mosquito age (1.2 d old and 35 d old), sex (male and female), source (laboratory and wild), and the time between conditioning and testing (<5 min, 1 hr, 2.5 hr, 5 hr, 10 hr, and 24 hr). Mosquitoes were individually conditioned to an odor across these different experimental conditions. Details of the conditioning protocol are presented as well as the use of binary logistic regression to analyze the complex dataset generated from this experimental design. The results suggest that each of the experimental factors may be important in different ways. Both the source of the mosquitoes and sex of the mosquitoes had significant effects on conditioned responses. The largest effect on conditioning was observed in the lack of positive response following conditioning for females aged 35 d derived from a long established colony. Overall, this study provides a method for conditioning experiments involving individual mosquitoes at close range and provides for future discussion of the relevance and broader questions that can be asked of olfactory conditioning in mosquitoes. PMID:21887384

Sanford, Michelle R.; Tomberlin, Jeffery K.

2011-01-01

304

The mosquito Aedes (Aedimorphus) vexans arabiensis as a probable vector bridging the West Nile virus between birds and horses in Barkedji (Ferlo, Senegal).  

PubMed

Active catches of adult females of Aedes vexans arabiensis Patton, (Diptera: Culicidae) Patton by nets or aspirator, were conducted in 2003 and 2004 in the vegetation at the edge of temporary ponds in Barkedji, Senegalese Ferlo area. Two hundred and forty-one engorged females were captured, dissected and the gut content adsorbed on a Whatman filter paper and analysed using the enzyme-linked immunosorbent assay (ELISA) technique to determinate the bloodmeal origin. Results indicated that Ae v. arabiensis fed primarily on mammals, including horses (35.7% of the bloodmeals), but also on birds (10%). Moreover, associations between horses and birds accounted for 42% of the mixed bloodmeals. These results show an opportunistic feeding behaviour and suggest that Ae v. arabiensis is a probable vector bridging the West Nile virus between horses and birds hosts in the Ferlo area. PMID:21790686

Fall, A G; Diat, A; Etter, E; Bouyer, J; Ndiaye, T D; Konat, L

2012-03-01

305

Spatiotemporal monitoring of floodwater mosquito dispersal in Osijek, Croatia.  

PubMed

This paper demonstrates the possibility of using geostatistics to monitor the dispersal of mosquitoes for mosquito control programs at the municipal level. The case study objective was to quantify the dispersal of floodwater mosquitoes from the natural marshland Kopacki rit into the city of Osijek, Croatia, and to analyze the main factors controlling it. Fifty thousand adult Aedes vexans, Ochlerotatus sticticus, and Ochlerotatus caspius mosquitoes were marked with a powdered fluorescent pigment and released from the southern part of Kopacki rit on April 28, 2004. Forty CO2-baited Centers for Disease Control and Prevention traps were set in the area of the municipality of Osijek (171 km2) and were monitored for 10 days. A total of 582,471 mosquitoes were captured and examined in the laboratory. The mosquito counts from different sites were then interpolated using ordinary kriging and visualized dynamically to detect the dominant migrational directions. Mosquito dispersal and frequency were greatly influenced by wind speed (r = 0.82). The marked mosquitoes were found at 12 sites located from 1 km to 11.7 km away from the release point. The recapture rate was 0.044% (54% Oc. sticticus, 32% Ae. vexans, and 14% Oc. caspius). Based on the Lincoln index, the estimated total population size for floodwater mosquitoes in the study area ranged from 875 million to 2.0 billion mosquitoes. Limitations of the approach, recommendations for the improvement of the monitoring network, and spatial predictions are further discussed. PMID:17847840

Bogojevi?, Mirta Sudari?; Hengl, Tomislav; Merdi?, Enrih

2007-06-01

306

Studies on prophenoloxidase activation in the mosquito Aedes aegypti L.  

PubMed

This study, the first of its kind in a mosquito vector species, demonstrates the feasibility of studying prophenoloxidase activation in an insect containing not more than a few microliters of hemolymph. Mosquito phenoloxidase was found to be in an inactive proenzyme form, prophenoloxidase. Mosquito prophenoloxidase required bivalent cation for its activation; Ca2+ was found to be the most efficient for activation. Concomitant amidase activity was also observed prior to phenoloxidase activity. Through Western blotting, using a cross-reactive silkworm antiprophenoloxidase antibody, our results strongly suggest that mosquito prophenoloxidase activation resulted from limited proteolysis. Protease inhibitor studies reinforced this contention showing the involvement of (a) serine protease(s) with trypsin-like activity in the activation of mosquito prophenoloxidase. PMID:2110057

Ashida, M; Kinoshita, K; Brey, P T

1990-03-30

307

Host feeding patterns of Connecticut mosquitoes (Diptera: Culicidae).  

PubMed

Blood-engorged Coquillettidia perturbans, Psorophora ferox, Culex, Culiseta, and Aedes mosquitoes were collected principally by sweep net from salt marsh and woodland habitats in Connecticut. Of the 570 mosquitoes tested, precipitin tests identified the origins of 517 blood meals and revealed distinct host feeding patterns. Aedes mosquitoes fed chiefly on mammals; A. abserratus, A. cantator, and A. vexans showed selectivity for cattle and (or) horses. A. cantator also obtained blood from avian hosts and, in some instances, showed mixed passerine-mammal blood meals. These findings increase the vector potential of this salt marsh mosquito for eastern equine encephalomyelitis virus. Feedings on deer by A. abserratus suggest potential involvement of this mosquito in the transmission of certain subtypes of California encephalitis. Culex-pipiens, C. restuans, Culiseta melanura, and Cs. morsitans dyari acquired blood almost exclusively from passeriform birds. PMID:17310

Magnarelli, L A

1977-05-01

308

Are Aedes albopictus or other mosquito species from northern Italy competent to sustain new arboviral outbreaks?  

PubMed

The Asian tiger mosquito Aedes albopictus (Skuse) (Diptera: Culicidae), native to Southeast Asia, has extended its geographical distribution to invade new temperate and tropical regions. This species was introduced in 1990 to Italy and has since become the main pest in urban settings. It was incriminated as a principal vector in the first European outbreak of chikungunya virus (CHIKV) in the province of Ravenna (Italy) in 2007. This outbreak was associated with CHIKV E1-226V, efficiently transmitted by Ae. albopictus. The occurrence of this outbreak in a temperate country led us to estimate the potential of Ae. albopictus to transmit CHIKV and dengue virus (DENV), and to determine the susceptibility to CHIKV of other mosquito species collected in northern Italy. Experimental infections showed that Ae. albopictus exhibited high disseminated infection rates for CHIKV (75.0% in Alessandria; 90.3% in San Lazzaro) and low disseminated infection rates for DENV-2 (14.3% in San Lazzaro; 38.5% in Alessandria). Moreover, Ae. albopictus was able to attain a high level of viral replication, with CHIKV detectable in the salivary glands at day 2 after infection. In addition, the other three mosquito species, Anopheles maculipennis Meigen, Aedes vexans vexans (Meigen) and Culex pipiens L., showed variable susceptibilities to infection with CHIKV, of 0%, 7.7% and 0-33%, respectively. This information on vector competence is crucial in assessing the risk for an outbreak of CHIKV or DENV in Italy. PMID:20377735

Talbalaghi, A; Moutailler, S; Vazeille, M; Failloux, A-B

2010-03-01

309

Green Nanoparticles for Mosquito Control  

PubMed Central

Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag) and gold (Au) nanoparticles (NPs) were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum) (C. zyelanicum or C. verum J. Presl). Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77?nm AgNPs and 46.48?nm AuNPs). The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito. PMID:25243210

Soni, Namita; Prakash, Soam

2014-01-01

310

Amazonian malaria: Asymptomatic human reservoirs, diagnostic challenges, environmentally-driven changes in mosquito vector populations, and the mandate for sustainable control strategies  

PubMed Central

Across the Americas and the Caribbean, nearly 561,000 slide-confirmed malaria infections were reported officially in 2008. The nine Amazonian countries accounted for 89% of these infections; Brazil and Peru alone contributed 56% and 7% of them, respectively. Local populations of the relatively neglected parasite P. vivax, which currently accounts for 77% of the regional malaria burden, are extremely diverse genetically and geographically structured. At a time when malaria elimination is placed on the public health agenda of several endemic countries, it remains unclear why malaria proved so difficult to control in areas of relatively low levels of transmission such as the Amazon Basin. We hypothesize that asymptomatic parasite carriage and massive environmental changes that affect vector abundance and behavior are major contributors to malaria transmission in epidemiologically diverse areas across the Amazon Basin. Here we review available data supporting this hypothesis and discuss their implications for current and future malaria intervention policies in the region. Given that locally generated scientific evidence is urgently required to support malaria control interventions in Amazonia, we briefly describe the aims of our current field-oriented malaria research in rural villages and gold-mining enclaves in Peru and a recently opened agricultural settlement in Brazil. PMID:22015425

da Silva-Nunes, Mnica; Moreno, Marta; Conn, Jan E.; Gamboa, Dionicia; Abeles, Shira; Vinetz, Joseph M.; Ferreira, Marcelo U.

2012-01-01

311

Analyzing Mosquito (Diptera: Culicidae) Diversity in Pakistan by DNA Barcoding  

PubMed Central

Background Although they are important disease vectors mosquito biodiversity in Pakistan is poorly known. Recent epidemics of dengue fever have revealed the need for more detailed understanding of the diversity and distributions of mosquito species in this region. DNA barcoding improves the accuracy of mosquito inventories because morphological differences between many species are subtle, leading to misidentifications. Methodology/Principal Findings Sequence variation in the barcode region of the mitochondrial COI gene was used to identify mosquito species, reveal genetic diversity, and map the distribution of the dengue-vector species in Pakistan. Analysis of 1684 mosquitoes from 491 sites in Punjab and Khyber Pakhtunkhwa during 20102013 revealed 32 species with the assemblage dominated by Culex quinquefasciatus (61% of the collection). The genus Aedes (Stegomyia) comprised 15% of the specimens, and was represented by six taxa with the two dengue vector species, Ae. albopictus and Ae. aegypti, dominant and broadly distributed. Anopheles made up another 6% of the catch with An. subpictus dominating. Barcode sequence divergence in conspecific specimens ranged from 02.4%, while congeneric species showed from 2.317.8% divergence. A global haplotype analysis of disease-vectors showed the presence of multiple haplotypes, although a single haplotype of each dengue-vector species was dominant in most countries. Geographic distribution of Ae. aegypti and Ae. albopictus showed the later species was dominant and found in both rural and urban environments. Conclusions As the first DNA-based analysis of mosquitoes in Pakistan, this study has begun the construction of a barcode reference library for the mosquitoes of this region. Levels of genetic diversity varied among species. Because of its capacity to differentiate species, even those with subtle morphological differences, DNA barcoding aids accurate tracking of vector populations. PMID:24827460

Ashfaq, Muhammad; Hebert, Paul D. N.; Mirza, Jawwad H.; Khan, Arif M.; Zafar, Yusuf; Mirza, M. Sajjad

2014-01-01

312

US Green Building Council Keys Branch Presents: Designing Mosquito Free Cisterns  

E-print Network

US Green Building Council Keys Branch Presents: Designing Mosquito Free Cisterns For Contractors from mosquito development, and the history of cisterns in the City of Key West and facts about, FGBC Certifying Agent, LEED BD+C **MAIN PRESENTATION ­ CISTERN MOSQUITO MITIGATION** By Michael Doyle

Watson, Craig A.

313

Title: Exploring Mosquito Larval Immunity upon Exposure to Larvicidal Bacillus Sphaericus  

E-print Network

1 of 2 Title: Exploring Mosquito Larval Immunity upon Exposure to Larvicidal Bacillus Sphaericus interactions among mosquito gut microbiota, Plasmodium, and host immunity in the context of gut microenvironment. Mosquito immunity studies have been mainly focusing on the adults. Larva-pathogen interaction

Johnson, Eric E.

314

Transstadial transmission of Francisella tularensis holarctica in mosquitoes, Sweden.  

PubMed

In Sweden, human cases of tularemia caused by Francisella tularensis holarctica are assumed to be transmitted by mosquitoes, but how mosquito vectors acquire and transmit the bacterium is not clear. To determine how transmission of this bacterium occurs, mosquito larvae were collected in an area where tularemia is endemic, brought to the laboratory, and reared to adults in their original pond water. Screening of adult mosquitoes by real-time PCR demonstrated F. tularensis lpnA sequences in 14 of the 48 mosquito pools tested; lpnA sequences were demonstrated in 6 of 9 identified mosquito species. Further analysis confirmed the presence of F. tularensis holarctica-specific 30-bp deletion region sequences (FtM19inDel) in water from breeding containers and in 3 mosquito species (Aedes sticticus, Ae. vexans, and Ae. punctor) known to take blood from humans. Our results suggest that the mosquitoes that transmit F. tularensis holarctica during tularemia outbreaks acquire the bacterium already as larvae. PMID:21529386

Lundstrm, Jan O; Andersson, Ann-Christin; Bckman, Stina; Schfer, Martina L; Forsman, Mats; Thelaus, Johanna

2011-05-01

315

Non-Genetic Determinants of Mosquito Competence for Malaria Parasites  

PubMed Central

Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control. Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence. Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects. However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions. Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions. We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies. Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies. PMID:23818841

Lefvre, Thierry; Vantaux, Amlie; Dabir, Kounbobr R.; Mouline, Karine; Cohuet, Anna

2013-01-01

316

Conserved Mosquito/Parasite Interactions Affect Development of Plasmodium falciparum in Africa  

PubMed Central

In much of sub-Saharan Africa, the mosquito Anopheles gambiae is the main vector of the major human malaria parasite, Plasmodium falciparum. Convenient laboratory studies have identified mosquito genes that affect positively or negatively the developmental cycle of the model rodent parasite, P. berghei. Here, we use transcription profiling and reverse genetics to explore whether five disparate mosquito gene regulators of P. berghei development are also pertinent to A. gambiae/P. falciparum interactions in semi-natural conditions, using field isolates of this parasite and geographically related mosquitoes. We detected broadly similar albeit not identical transcriptional responses of these genes to the two parasite species. Gene silencing established that two genes affect similarly both parasites: infections are hindered by the intracellular local activator of actin cytoskeleton dynamics, WASP, but promoted by the hemolymph lipid transporter, ApoII/I. Since P. berghei is not a natural parasite of A. gambiae, these data suggest that the effects of these genes have not been drastically altered by constant interaction and co-evolution of A. gambiae and P. falciparum; this conclusion allowed us to investigate further the mode of action of these two genes in the laboratory model system using a suite of genetic tools and infection assays. We showed that both genes act at the level of midgut invasion during the parasite's developmental transition from ookinete to oocyst. ApoII/I also affects the early stages of oocyst development. These are the first mosquito genes whose significant effects on P. falciparum field isolates have been established by direct experimentation. Importantly, they validate for semi-field human malaria transmission the concept of parasite antagonists and agonists. PMID:18483558

Cohuet, Anna; Awono-Ambene, Parfait; De Iorio, Maria; Fontenille, Didier; Morlais, Isabelle; Christophides, George K.; Kafatos, Fotis C.; Vlachou, Dina

2008-01-01

317

Dry season refugia for anopheline larvae and mapping of the seasonal distribution in mosquito larval habitats in Kandi, northeastern Benin  

PubMed Central

Background The dynamics of mosquito populations depends on availability of suitable surface water for oviposition. It is well known that suitable management of mosquito larval habitats in the sub-Saharan countries, particularly during droughts, could help to suppress vector densities and malaria transmission. We conducted a field survey to investigate the spatial and seasonal distribution of mosquito larval habitats and identify drought-refugia for anopheline larvae. Methods A GIS approach was used to identify, geo-reference and follow up longitudinally from May 2012 to May 2013, all mosquito breeding sites in two rural sites (Yondarou and Thui), one urban (Kossarou), and one peri-urban (Pd) site at Kandi, a municipality in northeastern Benin. In Kandi, droughts are excessive with no rain for nearly six months and a lot of sunshine. A comprehensive record of mosquito larval habitats was conducted periodically in all sites for the identification of drought-refugia of anopheline larval stages. With geospatialisation data, seasonal larval distribution maps were generated for each study site with the software ArcGIS version 10.2. Results Overall, 187 mosquito breeding sites were identified of which 29.95% were recorded during drought. In rural, peri-urban and urban sites, most of the drought-refugia of anopheline larvae were domestic in nature (61.54%). Moreover, in rural settings, anopheline larvae were also sampled in cisterns and wells (25% of larval habitats sampled during drought in Yondarou and 20% in Thui). The mapping showed a significant decrease in the spatial distribution of mosquito larval habitats in rural, peri-urban and urban sites during drought, except in Yondarou (rural) where the aridity did not seem to influence the distribution of larval habitats. Conclusion Our data showed that the main drought-refugia of anopheline larvae were of a domestic nature as well as wells and cisterns. A suitable management of mosquito larvae in sub-Saharan countries, particularly during droughts, should target such larval habitats for a meaningful impact on the dynamics of mosquito populations and malaria transmission. PMID:24684886

2014-01-01

318

Radiation biology of mosquitoes.  

PubMed

There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators. PMID:19917076

Helinski, Michelle E H; Parker, Andrew G; Knols, Bart G J

2009-01-01

319

Radiation biology of mosquitoes  

PubMed Central

There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators. PMID:19917076

Helinski, Michelle EH; Parker, Andrew G; Knols, Bart GJ

2009-01-01

320

Malaria-induced changes in host odors enhance mosquito attraction  

PubMed Central

Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analysesusing discriminant analysis of principal components and random forest approachesrevealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection. PMID:24982164

De Moraes, Consuelo M.; Stanczyk, Nina M.; Betz, Heike S.; Pulido, Hannier; Sim, Derek G.; Read, Andrew F.; Mescher, Mark C.

2014-01-01

321

A video clip of the biting midge Culicoides anophelis ingesting blood from an engorged Anopheles mosquito in Hainan, China  

PubMed Central

Background Biting midges are hematophagus ectoparasites of insects, humans and other animals. Culicoides (Trithicoides) anophelis Edwards1922 is a predator of engorged mosquitoes. Findings In a field trip of wild mosquito collections, C. anophelis was found on two Anopheles mosquitoes. One mosquito with a midge clinging onto its abdomen was caught on video demonstrating the act of the midge taking blood from the engorged mosquito Anopheles vagus. The midge C. anophelis has a broad host range. Documented in the literature, the midge has been found in various mosquito species in the genera Anopheles, Culex, Aedes and Armigeres. Conclusions A video clip was presented demonstrating a midge taking blood from an engorged mosquito. The host promiscuity of C. anophelis raises a concern about its potential as a mechanic or biological vector to spread viruses among mosquito populations. PMID:24499575

2013-01-01

322

The influence of malaria parasite genetic diversity and anaemia on mosquito feeding and fecundity  

E-print Network

The influence of malaria parasite genetic diversity and anaemia on mosquito feeding and fecundity H genetics and infection genetic diversity on the fecundity of mosquitoes carrying malaria parasites. The malaria vector Anopheles stephensi was infected with either of 2 different genotypes of the rodent malaria

Rivero, Ana

323

Mosquito repellent (pyrethroid-based) induced dysfunction of bloodbrain barrier permeability in developing brain  

Microsoft Academic Search

Pyrethroid-based mosquito repellents (MR) are commonly used to protect humans against mosquito vector. New born babies and children are often exposed to pyrethroids for long periods by the use of liquid vaporizers. Occupational and experimental studies indicate that pyrethroids can cause clinical, biochemical and neurological changes, and that exposure to pyrethroids during organogenesis and early developmental period is especially harmful.

C Sinha; A. K Agrawal; F Islam; K Seth; R. K Chaturvedi; S Shukla; P. K Seth

2004-01-01

324

Relative potency of various insecticides for use in ATSBs against mosquitoes and sand flies  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mosquitoes and sand flies are important throughout the world as nuisance pests and vectors of a variety of human and livestock diseases. Control efforts are limited often to adulticide sprays and larvicides, however, environmental concerns restrict their use. Both mosquitoes and sand flies need to...

325

Zoonotic Dirofilaria repens (Nematoda: Filarioidea) in Aedes vexans mosquitoes, Czech Republic.  

PubMed

The surveillance of vectors for arthropod-borne pathogens is nowadays an important tool in surveillance programmes throughout Europe. Whereas many studies have been performed to screen arthropods for viruses or bacterial pathogens, only limited information is available concerning the geographical distribution and vector range of pathogenic filariae in Central Europe. To consider the prevalence of filarial parasites in mosquito vectors, we performed a molecular survey of mosquitoes for filarial DNA. Mosquito collection was conducted at six study sites in the South Moravian region (Czech Republic) close to the borders with Slovakia and Austria from 2009 to 2011. Molecular screening of mosquitoes was conducted using conventional PCR with primers designed to amplify the mitochondrial cytochromoxidase subunit I gene as well as the partial 5.8S ribosomal RNA gene. A total of 13,222 mosquitoes belonging to six species were captured and distributed into 237 pools with different numbers of individuals. Overall, four pools were positive for Dirofilaria repens (a minimum infection rate 0.03%) at two study sites (both natural and urban). Another filarial parasite detected during a study into Aedes vexans mosquitoes revealed the closest homology to Setaria spp. We detected specific D. repens DNA in Ae. vexans mosquitoes for the first time in the Czech Republic and confirmed the circulation of Dirofilaria spp. in a natural focus of infection providing an epidemiological link between autochthonous canine cases and mosquito vectors in the area studied. PMID:25346197

Rudolf, Ivo; ebesta, Old?ich; Mendel, Jan; Betov, Lenka; Bockov, Eva; Jedli?kov, Petra; Venclkov, Kristna; Blaejov, Hana; ikutov, Silvie; Hublek, Zden?k

2014-12-01

326

Chikungunya Virus and Aedes Mosquitoes: Saliva Is Infectious as soon as Two Days after Oral Infection  

E-print Network

Chikungunya Virus and Aedes Mosquitoes: Saliva Is Infectious as soon as Two Days after Oral and Aedes albopictus are potential vectors of chikungunya virus (CHIKV). The recent CHIKV outbreaks were: Dubrulle M, Mousson L, Moutailler S, Vazeille M, Failloux A-B (2009) Chikungunya Virus and Aedes Mosquitoes

Boyer, Edmond

327

Applications of natural products in the control of mosquito-transmitted diseases  

Microsoft Academic Search

Mosquito-transmitted diseases remain one of the most significant causes of mortality in the African continent, despite successes in controlling these diseases in other regions of the world. The disproportionate impact in areas of poverty suggests a need for control that is efficient and does not require complex technological control strategies. Focusing on the vectors of disease, the mosquito, there are

Jesse A. Hardin; Fatimah L. C. Jackson

2009-01-01

328

Genetic Mapping of Specific Interactions between Aedes aegypti Mosquitoes and Dengue Viruses  

E-print Network

Genetic Mapping of Specific Interactions between Aedes aegypti Mosquitoes and Dengue Viruses. In this study, we aimed to determine whether G6G interactions observed between dengue viruses and their Aedes that G6G interactions between dengue viruses and mosquito vectors can be assigned to physical regions

Paris-Sud XI, Université de

329

Cold storage of the northern house mosquito, Culex pipiens, in the absence of diapause  

Technology Transfer Automated Retrieval System (TEKTRAN)

One major obstacle in vector biology experimentation is the rearing of mosquitoes. Most mosquito colonies require substantial effort to maintain, including a blood meal at least once a month for optimal performance. While the induction of diapause can be used to reduce the amount of work required ...

330

Predicting the risk of an endemic focus of Leishmania tropica becoming established in South-Western Europe through the presence of its main vector, Phlebotomus sergenti Parrot, 1917.  

PubMed

The aim of the study was the construction of risk maps for exposure to Phlebotomus sergenti, the main vector of Leishmania tropica, with a view to identifying hot spots for the potential establishment of this parasite in the southwest of Europe. Data were collected on the presence/absence of this vector and the ecological and climatic characteristics of 662 sampling sites located in the southeast, centre and northeast of the Iberian Peninsula (south-western Europe). The environmental factors associated with the distribution of P. sergenti were determined. The best predictors for the presence of this dipteran were altitude, land use, land surface temperature, aspect, adjacent land cover, absence of vegetation in wall and the absence of PVC pipes in the drainage holes of retaining walls. Risk maps for exposure to the vector were drawn up based on these variables. The validation of the predictive risk model confirmed its usefulness in the detection of areas with a high risk of P. sergenti being present. These locations represent potential hot spots for an autochthonous focus of L. tropica becoming established. The risk maps produced for P. sergenti presence revealed several areas in the centre and south of the Iberian Peninsula to be the most prone to this process, which would make it possible for the disease to enter south-western Europe. PMID:23965821

Barn, S D; Morillas-Mrquez, F; Morales-Yuste, M; Daz-Sez, V; Gllego, M; Molina, R; Martn-Snchez, J

2013-09-01

331

Insecticide resistance in mosquitoes: impact, mechanisms, and research directions.  

PubMed

Mosquito-borne diseases, the most well known of which is malaria, are among the leading causes of human deaths worldwide. Vector control is a very important part of the global strategy for management of mosquito-associated diseases, and insecticide application is the most important component in this effort. However, mosquito-borne diseases are now resurgent, largely because of the insecticide resistance that has developed in mosquito vectors and the drug resistance of pathogens. A large number of studies have shown that multiple, complex resistance mechanisms-in particular, increased metabolic detoxification of insecticides and decreased sensitivity of the target proteins-or genes are likely responsible for insecticide resistance. Gene overexpression and amplification, and mutations in protein-coding-gene regions, have frequently been implicated as well. However, no comprehensive understanding of the resistance mechanisms or regulation involved has yet been developed. This article reviews current knowledge of the molecular mechanisms, genes, gene interactions, and gene regulation governing the development of insecticide resistance in mosquitoes and discusses the potential impact of the latest research findings on the basic and practical aspects of mosquito resistance research. PMID:25564745

Liu, Nannan

2015-01-01

332

SCIENTIFIC NOTE SUSCEPTIBILITY OF FIELD-COLLECTED MOSQUITOES IN CENTRAL  

E-print Network

TO ORGANOPHOSPHATES AND A PYRETHROID DEBIN SUN,1,5 NICK INDELICATO,2,5 JACK PETERSEN,3 ERIC WILLIGES,1,3 ISIK UNLU 2 in local mosquito populations. Organophosphates and pyrethroids are 2 main classes of insecticides commonly

333

Distribution of anopheline mosquitoes in Eritrea.  

PubMed

The spatial distribution of anopheline mosquito species was studied throughout Eritrea during the 1999-2001 malaria transmission seasons from October to December for the highlands and western lowlands and February to April for the coastal region. Of the 302 villages sampled, 59 were visited in both the first and second year. Overall, 13 anopheline species were identified, with the Anopheles gambiae complex predominating during the first year (75.6%, n = 861) and the second year (91.9%, n = 1,262). Intrazonal variation accounted for 90% of the total variation in mosquito distribution. Polymerase chain reaction results indicated that 99% (n = 1,309) of the An. gambiae s.l. specimens were An. arabiensis, indicating that this was the only member of the gambiae complex present. There was a high degree of aggregation of anophelines within zones and villages, with more than 80% of the total anophelines being collected from less than 20% of the villages and from only 10% of the houses sampled. At least 80% of the anopheline mosquitoes were collected from grass-thatched Agudo-type housing. Vector abundance showed an inverse relationship with elevation, with highest densities in the low-lying western lowlands. Multiple regression analysis of log-transformed mean density of An. arabiensis with rainfall and the normalized difference vegetation index (NDVI) (average NDVI, minimum NDVI, and maximum NDVI) showed that these independent variables were not significantly associated with mosquito densities (R2 = 0.058). Our study contributes to the basic understanding of the ecology and distribution of malaria vectors with respect to species composition and spatial heterogeneities both that could be used to guide vector control operations in Eritrea. PMID:14628947

Shililu, Josephat; Ghebremeskel, Tewolde; Mengistu, Solomon; Fekadu, Helen; Zerom, Mehari; Mbogo, Charles; Githure, John; Gu, Weidong; Novak, Robert; Beier, John C

2003-09-01

334

Phylogeography and Genetic Variation of Triatoma dimidiata, the Main Chagas Disease Vector in Central America, and Its Position within the Genus Triatoma  

PubMed Central

Background Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T. dimidiata and its closest relatives within Triatoma. This is the largest interpopulational analysis performed on a triatomine species so far. Methodology and Findings Triatomines from Mexico, Guatemala, Honduras, Nicaragua, Panama, Cuba, Colombia, Ecuador, and Brazil were used. Triatoma dimidiata populations follow different evolutionary divergences in which geographical isolation appears to have had an important influence. A southern Mexicannorthern Guatemalan ancestral form gave rise to two main clades. One clade remained confined to the Yucatan peninsula and northern parts of Chiapas State, Guatemala, and Honduras, with extant descendants deserving specific status. Within the second clade, extant subspecies diversity was shaped by adaptive radiation derived from Guatemalan ancestral populations. Central American populations correspond to subspecies T. d. dimidiata. A southern spread into Panama and Colombia gave the T. d. capitata forms, and a northwestern spread rising from Guatemala into Mexico gave the T. d. maculipennis forms. Triatoma hegneri appears as a subspecific insular form. Conclusions The comparison with very numerous Triatoma species allows us to reach highly supported conclusions not only about T. dimidiata, but also on different, important Triatoma species groupings and their evolution. The very large intraspecific genetic variability found in T. dimidiata sensu lato has never been detected in a triatomine species before. The distinction between the five different taxa furnishes a new frame for future analyses of the different vector transmission capacities and epidemiological characteristics of Chagas disease. Results indicate that T. dimidiata will offer problems for control, although dwelling insecticide spraying might be successful against introduced populations in Ecuador. PMID:18461141

Bargues, Mara Dolores; Klisiowicz, Debora R.; Gonzalez-Candelas, Fernando; Ramsey, Janine M.; Monroy, Carlota; Ponce, Carlos; Salazar-Schettino, Paz Mara; Panzera, Francisco; Abad-Franch, Fernando; Sousa, Octavio E.; Schofield, Christopher J.; Dujardin, Jean Pierre; Guhl, Felipe; Mas-Coma, Santiago

2008-01-01

335

Geographic distribution of wolbachial infections in mosquitoes from Thailand.  

PubMed

Members of the genus Wolbachia are inherited intracellular bacterial endosymbionts that infect a diverse range of arthropods. Here I report the results of a survey of these endosymbionts in different mosquito species from six geographic regions of Northern, Northeastern, Western, Central, Eastern and Southern Thailand. Using gene amplification assays with wsp and groE gene primers, wolbachiae were detected in 999 mosquitoes representing 28 species of 1622 specimens collected representing 74 species of wild-caught mosquitoes from all regions of Thailand. Results using wsp primers were similar to those using groE primers in all cases. Wolbachiae had not been reported previously from five of the species tested, namely, Aedes lineatopennis, Aedes vexans, Aedes vittatus, Culex pallidothorax and Culex whitmorei. Infections were found in all major disease vector genera except Anopheles. These results indicate that wolbachial infections are distributed throughout many mosquito species in Thailand. PMID:23660513

Wiwatanaratanabutr, Itsanun

2013-11-01

336

Mosquito biology for the homeowner  

NSDL National Science Digital Library

A good resource site from Cornell's Entomology Department covering the biology and management of mosquitoes. This site is designed primarily for homeowners but there is some good, concise information for all interested in control of mosquitoes. Sections are clearly laid out with practical advice on what works and what does not in mosquito control including control of larvae, adults and personal protection from mosquitoes. A good reference list is provided at the end for anyone wishing to read more on mosquitoes. This is an excellent general mosquito reference with good, science-based recommendations. There are a few minor typographical errors that should be corrected.

0000-00-00

337

A recent survey of mosquito fauna in Guangdong Province,southern China, with a review of past records [corrected].  

PubMed

The southern province of Guangdong has long been subject to endemic mosquito-borne diseases. In recent years, this region of China has experienced rapid, extensive economic development involving environmental change, making much of the scant knowledge of its mosquito fauna obsolete. This paper reviews previous mosquito surveys, some of which may be too old to be of relevance to present-day conditions, and presents the results of a recent survey of adult and immature mosquitoes. The main vectors of mosquito-borne diseases endemic to the area, such as dengue and Japanese encephalitis virus, develop in container habitats. A three-year survey was carried out, between 2004 and 2006, of 4131 breeding containers in residential areas and in open, sparsely populated areas, of which approximately 50% were positive for the presence of mosquitoes, and 10 156 larvae and pupae were collected and identified. Twelve species were found in both residential and sparsely populated areas: Aedes albopictus (Skuse) (Diptera: Culicidae), Ae. lineatopennis (Ludlow), Ae. vexans (Meigen), Tanakaius togoi (Theobald), Culex barraudi Edwards, Cx dispectus Bram, Cx malayi (Leicester), Cx pallidothorax Theobald, Cx quinquefasciatus Say, Cx sitiens Wiedemann, Lutzia fuscanus Wiedemann and Tripteroides bambusa (Yamada). Armigeres subalbatus (Coquillett) was found only in containers in villages, whereas Ae. macfarlanei Edwards, Cx mimeticus No, Cx sinensis Theobald, Cx vegans Wiedemann, Cx wilfredi Colless and Mansonia uniformis (Theobald) were found only in non- or sparsely populated areas. In residential areas, the rank order of most common species, as measured by the proportion of containers colonized, was Ae. albopictus > Cx quinquefasciatus > Lu. fuscanus, whereas in sparsely populated areas the rank order was Cx quinquefasciatus > Ae. albopictus > Lu. fuscanus. Light traps in non- or sparsely populated areas caught 5995 adult mosquitoes of 25 species, some of which are not container breeders. The most common species were: Anopheles sinensis Wiedemann, An. maculatus Theobald, An. minimus Theobald, Ta. togoi, Cx bitaeniorhynchus Giles, Cx malayi, Cx quinquefasciatus, Cx sinensis Theobald, Cx sitiens, Cx tritaeniorhynchus Giles and Lu. fuscanus. It is noteworthy that nine species caught had not been previously recorded in Guangdong Province, highlighting the deficient knowledge of the current composition and distribution of the mosquito fauna of this part of China. PMID:19120964

Jin, L Q; Li, D

2008-12-01

338

UV light and urban pollution: bad cocktail for mosquitoes?  

PubMed

Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field. PMID:24275062

Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frdric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Rgent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stphane

2014-01-01

339

Trapping of Rift Valley Fever (RVF) vectors using Light Emitting Diode (LED) CDC traps in two arboviral disease hot spots in Kenya  

Technology Transfer Automated Retrieval System (TEKTRAN)

Background: Mosquitoes response to artificial lights including color has been exploited in trap designs for improved sampling of mosquito vectors. Earlier studies suggest that mosquitoes are attracted to specific wavelengths of light and thus the need to refine techniques to increase mosquito captu...

340

British Container Breeding Mosquitoes: The Impact of Urbanisation and Climate Change on Community Composition and Phenology  

PubMed Central

The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.421.3) per container than those in rural containers (77.715.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9C and 1.2C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK. PMID:24759617

Townroe, Susannah; Callaghan, Amanda

2014-01-01

341

Malaria Parasite Development in the Mosquito and Infection of the Mammalian Host  

PubMed Central

Plasmodium sporozoites are the product of a complex developmental process in the mosquito vector and are destined to infect the mammalian liver. Attention has been drawn to the mosquito stages and preerythrocytic stages owing to recognition that these are bottlenecks in the parasite life cycle and that intervention at these stages can block transmission and prevent infection. Parasite progression in the Anopheles mosquito, sporozoite transmission to the mammalian host by mosquito bite, and subsequent infection of the liver are characterized by extensive migration of invasive stages, cell invasion, and developmental changes. Preparation for the liver phase in the mammalian host begins in the mosquito with an extensive reprogramming of the sporozoite to support efficient infection and survival. Here, we discuss what is known about the molecular and cellular basis of the developmental progression of parasites and their interactions with host tissues in the mosquito and during the early phase of mammalian infection. PMID:19575563

Aly, Ahmed S.I.; Vaughan, Ashley M.; Kappe, Stefan H.I.

2010-01-01

342

Species composition and temporal distribution of mosquito populations in Ibadan, Southwestern Nigeria  

PubMed Central

Nigeria has a high burden of vector borne diseases such as malaria and lymphatic filariasis (LF). This study aimed to determine the species composition of mosquitoes in Ibadan, Southwest Nigeria as well as determine their role in malaria and LF transmission. Adult mosquitoes were collected by Pyrethrum Spray Catch (PSC) and identified and graded according to their abdominal conditions. The mosquitoes were dissected to determine the parity status and to check for microfilariae of Wuchereria bancrofti. The presence of circumsporozoite protein of Plasmodium falciparum was examined using ELISA. A total of 1600 mosquitoes were collected of which 31 (1.9%) were Anopheles gambiae s.l. while 1756 (98%) were Culex sp. None of the mosquitoes examined was positive for Plasmodium falciparum and Wuchereria bancrofti. The lack of adequate sanitary conditions in the area could be responsible for the large number of mosquitoes collected. Health education could help in sensitizing the inhabitants. PMID:25520960

Okorie, Patricia N.; Popoola, K.O.K.; Awobifa, Olayemi M.; Ibrahim, Kolade T.; Ademowo, George O.

2014-01-01

343

Francisella tularensis subspecies holarctica occurs in Swedish mosquitoes, persists through the developmental stages of laboratory-infected mosquitoes and is transmissible during blood feeding.  

PubMed

In Sweden, mosquitoes are considered the major vectors of the bacterium Francisella tularensis subsp. holarctica, which causes tularaemia. The aim of this study was to investigate whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults. Mosquitoes sampled in a Swedish area where tularaemia is endemic (rebro) were positive for the presence of F. tularensis deoxyribonucleic acid throughout the summer. Presence of the clinically relevant F. tularensis subsp. holarctica was confirmed in 11 out of the 14 mosquito species sampled. Experiments performed using laboratory-reared Aedes aegypti confirmed that F. tularensis subsp. holarctica was transstadially maintained from orally infected larvae to adult mosquitoes and that 25% of the adults exposed as larvae were positive for the presence of F. tularensis-specific sequences for at least 2 weeks. In addition, we found that F. tularensis subsp. holarctica was transmitted to 58% of the adult mosquitoes feeding on diseased mice. In a small-scale in vivo transmission experiment with F. tularensis subsp. holarctica-positive adult mosquitoes and susceptible mice, none of the animals developed tularaemia. However, we confirmed that there was transmission of the bacterium to blood vials by mosquitoes that had been exposed to the bacterium in the larval stage. Taken together, these results provide evidence that mosquitoes play a role in disease transmission in part of Sweden where tularaemia recurs. PMID:24057273

Thelaus, J; Andersson, A; Broman, T; Bckman, S; Granberg, M; Karlsson, L; Kuoppa, K; Larsson, E; Lundmark, E; Lundstrm, J O; Mathisen, P; Nslund, J; Schfer, M; Wahab, T; Forsman, M

2014-01-01

344

Post Flood Alternatives Mosquito Flats  

E-print Network

Post Flood Alternatives for Mosquito Flats (an amateur perspective, continued) Douglas Jones 816 for Mosquito Flats to the Iowa City City Council. This document presents a refined version of the preferred for a buyout of floodplain property in Mosquito Flats. Before presenting my recommendation, I will present

Jones, Douglas W.

345

Etiology of interepidemic periods of mosquito-borne disease  

Microsoft Academic Search

Dengue viruses and malaria protozoa are of increasing global concern in public health. The diseases caused by these pathogens often show regular seasonal patterns in incidence because of the sensitivity of their mosquito vectors to climate. Between years in endemic areas, however, there can be further significant variation in case numbers for which public health systems are generally unprepared. There

Simon I. Hay; Monica F. Myers; Donald S. Burke; David W. Vaughn; Nisalak Anandai; G. Dennis Shanksi; Robert W. Snow; David J. Rogers

2000-01-01

346

Response of the mosquito protein interaction network to dengue infection  

Microsoft Academic Search

BACKGROUND: Two fifths of the world's population is at risk from dengue. The absence of effective drugs and vaccines leaves vector control as the primary intervention tool. Understanding dengue virus (DENV) host interactions is essential for the development of novel control strategies. The availability of genome sequences for both human and mosquito host greatly facilitates genome-wide studies of DENV-host interactions.

Xiang Guo; Yao Xu; Guowu Bian; Andrew D Pike; Yan Xie; Zhiyong Xi

2010-01-01

347

The entomopathogenic fungus Beauveria bassiana reduces instantaneous blood feeding in wild multi-insecticide-resistant Culex quinquefasciatus mosquitoes in Benin, West Africa  

Microsoft Academic Search

BACKGROUND: Mosquito-borne diseases are still a major health risk in many developing countries, and the emergence of multi-insecticide-resistant mosquitoes is threatening the future of vector control. Therefore, new tools that can manage resistant mosquitoes are required. Laboratory studies show that entomopathogenic fungi can kill insecticide-resistant malaria vectors but this needs to be verified in the field. METHODS: The present study

Annabel FV Howard; Raphael N'Guessan; Constantianus JM Koenraadt; Alex Asidi; Marit Farenhorst; Martin Akogbto; Matthew B Thomas; Bart GJ Knols; Willem Takken

2010-01-01

348

Isolations of Jamestown Canyon Virus (Bunyaviridae: Orthobunyavirus ) from Field-Collected Mosquitoes (Diptera: Culicidae) in Connecticut, USA: A Ten-Year Analysis, 19972006  

Microsoft Academic Search

Jamestown Canyon virus (JCV) (Bunyaviridae: Orthobunyavirus) is a mosquito-borne zoonosis belonging to the California serogroup. It has a wide geographic distribution, occurring throughout much of temperate North Amer- ica. White-tailed deer, Odocoileus virginianus are the principal amplification hosts, and boreal Aedes and Ochlero- tatus mosquitoes are the primary vectors. A 10-year study was undertaken to identify potential mosquito vectors in

Theodore G. Andreadis; John F. Anderson; Philip M. Armstrong; Andrew J. Main

2008-01-01

349

Flavivirus-mosquito interactions.  

PubMed

The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1-4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations. PMID:25421894

Huang, Yan-Jang S; Higgs, Stephen; Horne, Kate McElroy; Vanlandingham, Dana L

2014-11-01

350

Flavivirus-Mosquito Interactions  

PubMed Central

The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 14, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations. PMID:25421894

Huang, Yan-Jang S.; Higgs, Stephen; Horne, Kate McElroy; Vanlandingham, Dana L.

2014-01-01

351

Fauna of mosquito larvae (Diptera: Culicida) in Asir Provence, Kingdom of Saudi Arabia.  

PubMed

An entomological survey was undertaken for one year to update the mosquito fauna of Asir Region, Kingdom of Saudi Arabia. A total of 31 species of 8 genera were reported of which genus Culex (55%) was the most common. Most of collected larvae (59%) belonged to genus Culex (+ Lutzia) followed by Culiseta (26%), Anopheles (13%) and Aedine spp. (2%). Cx. pipiens (39%) and Cs. longiareolata (26.%) were generally the most abundant of all collected larvae. Of the Anopheles spp., An. dthali was common (40%), of Culex spp., Cx. pipiens was predominating (66%) and of Aedine spp., St. aegypti was predominating (71%). Four species: An. fluviatilis, Cx. mattinglyi, Cx. arbieeni and Cx. mimeticus were new reports in Asir Region and Cx. wigglesworthi recorded for the first time from the kingdom. Larvae were more common in low- and highlands than in the moderately altitude areas. In general all species prefer stagnant water but with the exception of Aedine larvae (altogether), the other species prefer presence of algae, vegetation and shade and absence of turbidity (except Culex spp.). A total of 98 different forms of association were reported of which 9 forms were common. All genera breed year round with peaks of abundance during spring for Anopheles spp. and Culex spp. and during winter for Aedine spp. and Cs. longiareolata. A complete list of mosquito fauna of Asir Region comprising 45 spp. was presented based on the present and previous surveys. The study concluded that the occurrence and prevalence of mosquito species mainly the disease vectors in Asir carry the thread of maintaining and transmission of several mosquito-borne diseases. PMID:24961023

Al Ashry, Hamdy A; Kenawy, Mohamed A; Shobrak, Mohammed

2014-04-01

352

Higher Mosquito Production in Low-Income Neighborhoods of Baltimore and Washington, DC: Understanding Ecological Drivers and Mosquito-Borne Disease Risk in Temperate Cities  

PubMed Central

Mosquito-vectored pathogens are responsible for devastating human diseases and are (re)emerging in many urban environments. Effective mosquito control in urban landscapes relies on improved understanding of the complex interactions between the ecological and social factors that define where mosquito populations can grow. We compared the density of mosquito habitat and pupae production across economically varying neighborhoods in two temperate U.S. cities (Baltimore, MD and Washington, DC). Seven species of mosquito larvae were recorded. The invasive Aedes albopictus was the only species found in all neighborhoods. Culex pipiens, a primary vector of West Nile virus (WNV), was most abundant in Baltimore, which also had more tire habitats. Both Culex and Aedes pupae were more likely to be sampled in neighborhoods categorized as being below median income level in each city and Aedes pupae density was also greater in container habitats found in these lower income neighborhoods. We infer that lower income residents may experience greater exposure to potential disease vectors and Baltimore residents specifically, were at greater risk of exposure to the predominant WNV vector. However, we also found that resident-reported mosquito nuisance was not correlated with our measured risk index, indicating a potentially important mismatch between motivation needed to engage participation in control efforts and the relative importance of control among neighborhoods. PMID:23583963

LaDeau, Shannon L.; Leisnham, Paul T.; Biehler, Dawn; Bodner, Danielle

2013-01-01

353

Higher mosquito production in low-income neighborhoods of Baltimore and Washington, DC: understanding ecological drivers and mosquito-borne disease risk in temperate cities.  

PubMed

Mosquito-vectored pathogens are responsible for devastating human diseases and are (re)emerging in many urban environments. Effective mosquito control in urban landscapes relies on improved understanding of the complex interactions between the ecological and social factors that define where mosquito populations can grow. We compared the density of mosquito habitat and pupae production across economically varying neighborhoods in two temperate U.S. cities (Baltimore, MD and Washington, DC). Seven species of mosquito larvae were recorded. The invasive Aedes albopictus was the only species found in all neighborhoods. Culex pipiens, a primary vector of West Nile virus (WNV), was most abundant in Baltimore, which also had more tire habitats. Both Culex and Aedes pupae were more likely to be sampled in neighborhoods categorized as being below median income level in each city and Aedes pupae density was also greater in container habitats found in these lower income neighborhoods. We infer that lower income residents may experience greater exposure to potential disease vectors and Baltimore residents specifically, were at greater risk of exposure to the predominant WNV vector. However, we also found that resident-reported mosquito nuisance was not correlated with our measured risk index, indicating a potentially important mismatch between motivation needed to engage participation in control efforts and the relative importance of control among neighborhoods. PMID:23583963

LaDeau, Shannon L; Leisnham, Paul T; Biehler, Dawn; Bodner, Danielle

2013-04-01

354

Mosquito (Diptera: Culicidae) Fauna of Qom Province, Iran  

PubMed Central

Background There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province. Methods: To study the mosquito (Diptera: Culicidae) fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009. Results: In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed. Conclusion: There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively. PMID:23293779

Saghafipour, A; Abai, MR; Farzinnia, B; Nafar, R; Ladonni, H; Azari-Hamidian, S

2012-01-01

355

Aedes vexans and Culex pipiens as the potential vectors of Dirofilaria immitis in Central Turkey.  

PubMed

This study was carried out to investigate the potential vectors and relative mosquito infection rates of Dirofilaria immitis throughout two mosquito seasons (2008-2009) in Kayseri province where is located in Central Anatolian part of Turkey. For this aim, totally 1198 genomic DNA pools, extracted and grouped according to the species and collection site (1-17 specimens/pool) from 6153 mosquito specimens, were examined by PCR using species-specific primers for D. immitis. The captured mosquitoes from 46 focuses were survived under in vitro conditions for 7 days to allow the development of larval stages of D. immitis. DNA extraction was performed individually to both thorax-head and abdomens in order to determine infective and infected mosquito specimens, respectively. The most abundant mosquito species in the study area was determined as Ae. vexans (51.7%) and this was followed by Cx. pipiens (42.1%), Cx. theileri (3.1%), Cs. annulata (1.5%), An. maculipennis (1.0%) and Cx. hortensis (0.6%). The PCR results indicated that 9/312 and 12/312 pools from Ae. vexans abdomens and thorax-heads were positive for filarial DNAs, respectively where as 3/241 pools of each abdomens and thorax-heads from Cx. pipiens were positive for D. immitis DNAs. The minimum infection rates (MIRs) for Ae. vexans and Cx. pipiens were calculated as 0.41 and 0.12, respectively. Although D. immitis DNA's were found in both pools from Ae. vexans and Cx. pipiens, the calculated MIRs provide evidence that Ae. vexans could be the main potential vector of D. immitis in Kayseri. PMID:21232866

Yildirim, A; Inci, A; Duzlu, O; Biskin, Z; Ica, A; Sahin, I

2011-05-31

356

The remarkable journey of adaptation of the Plasmodium falciparum malaria parasite to New World anopheline mosquitoes  

PubMed Central

Plasmodium falciparum originated in Africa, dispersed around the world as a result of human migration and had to adapt to several different indigenous anopheline mosquitoes. Anophelines from the New World are evolutionary distant form African ones and this probably resulted in a more stringent selection of Plasmodium as it adapted to these vectors. It is thought that Plasmodium has been genetically selected by some anopheline species through unknown mechanisms. The mosquito immune system can greatly limit infection and P. falciparum evolved a strategy to evade these responses, at least in part mediated by Pfs47, a highly polymorphic gene. We propose that adaptation of P. falciparum to new vectors may require evasion of their immune system. Parasites with a Pfs47 haplotype compatible with the indigenous mosquito vector would be able to survive and be transmitted. The mosquito antiplasmodial response could be an important determinant of P. falciparum population structure and could affect malaria transmission in the Americas. PMID:25185006

Molina-Cruz, Alvaro; Barillas-Mury, Carolina

2014-01-01

357

Investigations of Koutango Virus Infectivity and Dissemination Dynamics in Aedes aegypti Mosquitoes  

PubMed Central

Aedes aegypti has already been implicated in the emergence of dengue and chikungunya viruses in the southern US. Vector competence is the ability of a mosquito species to support transmission of an arbovirus, which is bounded by its ability to support replication and dissemination of the virus through the mosquito body to the salivary glands to be expectorated in the saliva at the time of feeding on a vertebrate host. Here, we investigate the vector competence of A. aegypti for the arbovirus koutango by orally challenging mosquitoes with two titers of virus. We calculated the effective vector competence, a cumulative measure of transmission capability weighted by mosquito survival, and determined that A. aegypti was competent at the higher dose only. We conclude that further investigation is needed to determine the infectiousness of vertebrate hosts to fully assess the emergence potential of this virus in areas rich in A. aegypti. PMID:25574140

de Arajo Lobo, Jaime M; Christofferson, Rebecca C; Mores, Christopher N

2014-01-01

358

Taxis assays measure directional movement of mosquitoes to olfactory cues  

PubMed Central

Background Malaria control methods targeting indoor-biting mosquitoes have limited impact on vectors that feed and rest outdoors. Exploiting mosquito olfactory behaviour to reduce blood-feeding outdoors might be a sustainable approach to complement existing control strategies. Methodologies that can objectively quantify responses to odour under realistic field conditions and allow high-throughput screening of many compounds are required for development of effective odour-based control strategies. Methods The olfactory responses of laboratory-reared Anopheles gambiae in a semi-field tunnel and A. arabiensis females in an outdoor field setting to three stimuli, namely whole human odour, a synthetic blend of carboxylic acids plus carbon dioxide and CO2 alone at four distances up to 100 metres were measured in two experiments using three-chambered taxis boxes that allow mosquito responses to natural or experimentally-introduced odour cues to be quantified. Results Taxis box assays could detect both activation of flight and directional mosquito movement. Significantly more (6-18%) A. arabiensis mosquitoes were attracted to natural human odour in the field up to 30 metres compared to controls, and blended synthetic human odours attracted 20% more A. gambiae in the semi-field tunnel up to 70 metres. Whereas CO2 elicited no response in A. arabiensis in the open field, it was attractive to A. gambiae up to 50 metres (65% attraction compared to 36% in controls). Conclusions We have developed a simple reproducible system to allow for the comparison of compounds that are active over medium- to long-ranges in semi-field or full-field environments. Knowing the natural range of attraction of anopheline mosquitoes to potential blood sources has substantial implications for the design of malaria control strategies, and adds to the understanding of olfactory behaviour in mosquitoes. This experimental strategy could also be extended from malaria vectors to other motile arthropods of medical, veterinary and agricultural significance. PMID:23642138

2013-01-01

359

Play the Mosquito Game  

MedlinePLUS

... and Work Teachers' Questionnaire Malaria Play the Mosquito Game Play the Parasite Game About the games Malaria is one of the world's most common ... last will in Paris. Play the Blood Typing Game Try to save some patients and learn about ...

360

Preferential feeding success of laboratory reared Anopheles stephensi mosquitoes according to ABO blood group status.  

PubMed

Recent epidemiological evidences revealed a higher rate of O blood group in the residents of malaria-endemic areas suggesting that groups A, B, and AB associated with a higher disease severity and fatality. Also recent data showed the low prevalence of AB group within the malaria-endemic residents in south of Iran and India. The aim of this study was to determine the ABO blood groups preference of Anopheles stephensi which is the main malaria vector in Iran, southwest Asia, and India. An. stephensi mosquitoes were fed either artificially on A/B/O/AB membrane blood feeders or directly on human volunteer hands and forearms of A/B/O/AB groups in a cage under lab conditions. Phenotype and genotype analyzes of 450-blood-fed mosquito specimens using agglutination and multiplex-allele-specific PCR revealed a significant blood preference of An. stephensi to AB group (40%) than other groups of A (24%), B (21%), and O (15%) in combination of both experiments. High preference of An. stephensi to AB group might increase malaria infection and fatality in this blood group and resulted in low frequency of AB group in the residents of malaria endemic areas. The data suggested that malaria vectors, like parasites may have selection pressure on human genotypes. PMID:25151045

Anjomruz, Mehdi; Oshaghi, Mohammad A; Pourfatollah, Ali A; Sedaghat, Mohammad M; Raeisi, Ahmad; Vatandoost, Hassan; Khamesipour, Ali; Abai, Mohammad R; Mohtarami, Fatemeh; Akbarzadeh, Kamran; Rafie, Fatemeh; Besharati, Mahdiyeh

2014-12-01

361

Comprehensive sterilization of malaria vectors using pyriproxyfen: a step closer to malaria elimination.  

PubMed

One of the main challenges to malaria elimination is the resilience of vectors, such as Anopheles arabiensis, that evade lethal exposure to insecticidal control measures or express resistance to their active ingredients. This study investigated a novel technology for population control that sterilizes mosquitoes using pyriproxyfen, a juvenile hormone analogue. Females of An. arabiensis were released in a semifield system divided into four equal sections, and each section had a mud hut sheltering a tethered cow providing a blood source for mosquitoes. In all sections, the inner mud hut walls and roofs were lined with black cotton cloth. In one-half of the sections, the cloth was dusted with pyriproxyfen. An overwhelming 96% reduction in adult production was achieved in pyriproxyfen-treated sections compared with control sections. This unprecedented level of control can be exploited to design new vector control strategies that particularly target existing behaviorally resilient and insecticide-resistant populations. PMID:24639296

Lwetoijera, Dickson W; Harris, Caroline; Kiware, Samson S; Killeen, Gerry F; Dongus, Stefan; Devine, Gregor J; Majambere, Silas

2014-05-01

362

Wolbachia enhances West Nile virus (WNV) infection in the mosquito Culex tarsalis.  

PubMed

Novel strategies are required to control mosquitoes and the pathogens they transmit. One attractive approach involves maternally inherited endosymbiotic Wolbachia bacteria. After artificial infection with Wolbachia, many mosquitoes become refractory to infection and transmission of diverse pathogens. We evaluated the effects of Wolbachia (wAlbB strain) on infection, dissemination and transmission of West Nile virus (WNV) in the naturally uninfected mosquito Culex tarsalis, which is an important WNV vector in North America. After inoculation into adult female mosquitoes, Wolbachia reached high titers and disseminated widely to numerous tissues including the head, thoracic flight muscles, fat body and ovarian follicles. Contrary to other systems, Wolbachia did not inhibit WNV in this mosquito. Rather, WNV infection rate was significantly higher in Wolbachia-infected mosquitoes compared to controls. Quantitative PCR of selected innate immune genes indicated that REL1 (the activator of the antiviral Toll immune pathway) was down regulated in Wolbachia-infected relative to control mosquitoes. This is the first observation of Wolbachia-induced enhancement of a human pathogen in mosquitoes, suggesting that caution should be applied before releasing Wolbachia-infected insects as part of a vector-borne disease control program. PMID:25010200

Dodson, Brittany L; Hughes, Grant L; Paul, Oluwatobi; Matacchiero, Amy C; Kramer, Laura D; Rasgon, Jason L

2014-07-01

363

A portable approach for the surveillance of dengue virus-infected mosquitoes.  

PubMed

Dengue virus is the most significant human viral pathogen spread by the bite of an infected mosquito. With no vaccine or antiviral therapy currently available, disease prevention relies largely on surveillance and mosquito control. Preventing the onset of dengue outbreaks and effective vector management would be considerably enhanced through surveillance of dengue virus prevalence in natural mosquito populations. However, current approaches to the identification of virus in field-caught mosquitoes require relatively slow and labor intensive techniques such as virus isolation or RT-PCR involving specialized facilities and personnel. A rapid and portable method for detecting dengue virus-infected mosquitoes is described. Using a hand held battery operated homogenizer and a dengue diagnostic rapid strip the viral protein NS1 was detected as a marker of dengue virus infection. This method could be performed in less than 30 min in the field, requiring no downstream processing, and is able to detect a single infected mosquito in a pool of at least 50 uninfected mosquitoes. The method described in this study allows rapid, real-time monitoring of dengue virus presence in mosquito populations and could be a useful addition to effective monitoring and vector control responses. PMID:22575689

Muller, David A; Frentiu, Francesca D; Rojas, Alejandra; Moreira, Luciano A; O'Neill, Scott L; Young, Paul R

2012-07-01

364

Modulation of La Crosse Virus Infection in Aedes albopictus Mosquitoes Following Larval Exposure to Coffee Extracts  

PubMed Central

The mosquito-borne La Crosse virus (LACV; Family Bunyaviridae) may cause encephalitis, primarily in children, and is distributed throughout much of the eastern United States. No antivirals or vaccines are available for LACV, or most other mosquito-borne viruses, and prevention generally relies on mosquito control. We sought to determine whether coffee extracts could interfere with LACV replication and vector mosquito development. Both regular and decaffeinated coffee demonstrated significant reductions in LACV replication in direct antiviral assays. This activity was not due to the presence of caffeine, which did not inhibit the virus life cycle. Aedes albopictus (Skuse; Diptera: Culicidae) mosquito larvae suffered near total mortality when reared in high concentrations of regular and decaffeinated coffee and in caffeine. Following larval exposure to sublethal coffee concentrations, adult A. albopictus mosquitoes had significantly reduced whole-body LACV titers 5?days post-infection, compared to larvae reared in distilled water. These results suggest that it may be possible to both control mosquito populations and alter the vector competence of mosquitoes for arthropod-borne viruses by introducing antiviral compounds into the larval habitat. PMID:22470349

Eastep, Nicole E.; Albert, Rachel E.; Anderson, Justin R.

2012-01-01

365

Bottlenecks and multiple introductions: population genetics of the vector of avian malaria in Hawaii.  

PubMed

Avian malaria has had a profound impact on the demographics and behaviour of Hawaiian forest birds since its vector, Culex quinquefasciatus the southern house mosquito, was first introduced to Hawaii around 1830. In order to understand the dynamics of the disease in Hawaii and gain insights into the evolution of vector-mediated parasite-host interactions in general we studied the population genetics of Cx. quinquefasciatus in the Hawaiian Islands. We used both microsatellite and mitochondrial loci. Not surprisingly we found that mosquitoes in Midway, a small island in the Western group, are quite distinct from the populations in the main Hawaiian Islands. However, we also found that in general mosquito populations are relatively isolated even among the main islands, in particular between Hawaii (the Big Island) and the remaining Hawaiian Islands. We found evidence of bottlenecks among populations within the Big Island and an excess of alleles in Maui, the site of the original introduction. The mitochondrial diversity was typically low but higher than expected. The current distribution of mitochondrial haplotypes combined with the microsatellite information lead us to conclude that there have been several introductions and to speculate on some processes that may be responsible for the current population genetics of vectors of avian malaria in Hawaii. PMID:11091316

Fonseca, D M; LaPointe, D A; Fleischer, R C

2000-11-01

366

Bottlenecks and multiple introductions: Population genetics of the vector of avian malaria in Hawaii  

USGS Publications Warehouse

Avian malaria has had a profound impact on the demographics and behaviour of Hawaiian forest birds since its vector, Culex quinquefasciatus the southern house mosquito, was first introduced to Hawaii around 1830. In order to understand the dynamics of the disease in Hawaii and gain insights into the evolution of vector-mediated parasite-host interactions in general we studied the population genetics of Cx. quinquefasciatus in the Hawaiian Islands. We used both microsatellite and mitochondrial loci. Not surprisingly we found that mosquitoes in Midway, a small island in the Western group, are quite distinct from the populations in the main Hawaiian Islands. However, we also found that in general mosquito populations are relatively isolated even among the main islands, in particular between Hawaii (the Big Island) and the remaining Hawaiian Islands. We found evidence of bottlenecks among populations within the Big Island and an excess of alleles in Maui, the site of the original introduction. The mitochondrial diversity was typically low but higher than expected. The current distribution of mitochondrial haplotypes combined with the microsatellite information lead us to conclude that there have been several introductions and to speculate on some processes that may be responsible for the current population genetics of vectors of avian malaria in Hawaii.

Fonseca, D.M.; Lapointe, D.A.; Fleischer, R.C.

2000-01-01

367

[Highest mosquito records (Diptera: Culicidae) in Venezuela].  

PubMed

Mosquitoes (Diptera: Culicidae) are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants) and artificial deposits. The availability of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9,607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3,133 m, followed by three species of Anopheles--subgenera Kerteszia--with the upper limit of 2,680 m. Wyeomyia bicornis and Culex daumastocampa at 2,550 m were the highest records in the Central-Coastal cordillera, while the highest record in Pantepui was Wyeomyia zinzala at 2,252 m. The species associated with phytothelmata (Bromeliaceae and Sarraceniaceae) represent 60% of the records. The upper limits of Culex quinquefasciatus and Anopheles (Kerteszia) species could represent the theoretical limit for transmission of filariasis or arboviruses, by Culex, and malaria by Anopheles (Kerteszia) in Venezuela. Similarly, a vector of Dengue, Aedes aegypti, has not been not recorded above 2,000 m. PMID:20411719

Navarro, Juan-Carlos; Del Ventura, Fabiola; Zorrilla, Adriana; Liria, Jonathan

2010-03-01

368

Prevalence of avian malaria parasite in mosquitoes collected at a zoological garden in Japan.  

PubMed

Several species of captive birds at zoological gardens of Japan were found to be infected with avian Plasmodium. However, incriminated vector mosquito species have not been identified yet. To indicate the competent vectors of avian malaria parasite, we collected mosquitoes at a zoological garden in Japan and examined for the avian malaria parasite DNA. Totally, 1,361 mosquitoes of 11 species were collected in the zoological garden of Kanagawa, the south of Tokyo in Japan in 2005. Captured mosquitoes were pooled by each species, date collected, and location and used for DNA extraction. Eight out of 169 DNA samples were positive for the nested PCR of avian Plasmodium cyt b gene. Estimated minimum infection rates of mosquitoes were 5.9 per 1,000. The PCR positive mosquito species were Culex pipiens group and Lutzia vorax. Some DNA sequences amplified from collected mosquitoes were identical to avian Plasmodium lineages detected from captive birds in the same zoological garden studied. Our results suggest that C. pipiens group and L. vorax could be incriminated vectors of avian malaria parasite transmitting in captive birds kept in the zoological garden in Japan. PMID:19352704

Ejiri, Hiroko; Sato, Yukita; Sawai, Risa; Sasaki, Emi; Matsumoto, Rei; Ueda, Miya; Higa, Yukiko; Tsuda, Yoshio; Omori, Sumie; Murata, Koichi; Yukawa, Masayoshi

2009-09-01

369

Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes  

PubMed Central

A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L.) abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito population, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT) and BG-Sentinel (BGS) traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship). For MQT, only the number of rainy days in the previous week was significant (in a negative relationship). The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus. PMID:25494470

Degener, Carolin Marlen; de zara, Tatiana Mingote Ferreira; Roque, Rosemary Aparecida; Codeo, Cludia Torres; Nobre, Aline Arajo; Ohly, Jrg Johannes; Geier, Martin; Eiras, lvaro Eduardo

2014-01-01

370

Biochem. J. (2013) 455, 7585 (Printed in Great Britain) doi:10.1042/BJ20130577 75 The central role of mosquito cytochrome P450 CYP6Zs in insecticide  

E-print Network

of mosquito cytochrome P450 CYP6Zs in insecticide detoxification revealed by functional expression, Lausanne 1015, Switzerland The resistance of mosquitoes to chemical insecticides is threatening vector, members of the mosquito CYP6Z subfamily, like Aedes aegypti CYP6Z8 and its Anopheles gambiae orthologue

Alvarez, Nadir

371

Molecular survey of Dirofilaria immitis and Dirofilaria repens by direct PCR for wild caught mosquitoes in the Republic of Korea  

Microsoft Academic Search

Adult mosquito collections using New Jersey light traps and Black-hole light traps were conducted to determine the potential vectors and the relative mosquito infection rates of Dirofilaria immitis and Dirofilaria repens in Gyeonggi and Gangwon Provinces, Republic of Korea, 2005. Dirofilaria spp. were confirmed by polymerase chain reaction (PCR) using species-specific primers for D. immitis and D. repens. Minimum field

Sang-Eun Lee; Heung-Chul Kim; Sung-Tae Chong; Terry A. Klein; Won-Ja Lee

2007-01-01

372

Prevalence of Dirofilaria immitis (Nematoda: Filarioidea) in mosquitoes from northeast Arkansas, the United States.  

PubMed

A mosquito survey was conducted to identify which species of mosquitoes carry Dirofilaria immitis (Leidy) (Nematoda: Filarioidea), dog heartworm, in northeast Arkansas. Using polymerase chain reaction, mosquitoes were analyzed for D. immitis, Dirofilaria repens Railliet & Henry, and Acanthocheilonema dracunculoides Cobbold. Mosquitoes were collected from April to October 2009 using black light ultraviolet traps baited with dry ice. Sixteen mosquito species were identified. D. immitis was identified in nine mosquito species, which included Aedes vexans (Meigen), Anopheles quadrimaculatus Say, Anopheles punctipennis (Say), Culex pipiens quinquefasciatus Say, Culex erraticus (Dyer & Knab), Culiseta inornata (Williston), Psorophora columbiae (Dyer & Knab), Psorophora ferox (Humboldt), and Psorophora howardii Coquillett. No D. repens or A. dracunculoides DNA was amplified. Of the 1,212 mosquito pools tested, 7.3% were positive for D. immitis. Frequency of D. immitis infections from six collection sites ranged from 2.1 to 19.4%. Ae. vexans and An. quadrimaculatus were the two most abundant species, composing 58.7 and 23.7% of the total mosquitoes collected, with 9.6 and 6.9% of pools positive for D. immitis, respectively. To investigate localized vector infection rates of D. immitis, mosquitoes were collected from inside the kennel of a heartworm-positive dog. Of the 114 mosquitoes collected, 84 (73.7%) were positive for D. immitis. The frequency of D. immitis-infected mosquitoes collected near a heartworm-positive dog was considerably higher than in the original six collection sites, suggesting a single heartworm-positive dog potentially increases infection pressure on susceptible animals sharing mosquito exposure. PMID:23926787

Mckay, Tanja; Bianco, T; Rhodes, L; Barnett, S

2013-07-01

373

Health research ethics in malaria vector trials in Africa  

PubMed Central

Malaria mosquito research in Africa as elsewhere is just over a century old. Early trials for development of mosquito control tools were driven by colonial enterprises and war efforts; they were, therefore, tested in military or colonial settings. The failure of those tools and environmental concerns, coupled with the desperate need for integrated malaria control strategies, has necessitated the development of new malaria mosquito control tools, which are to be tested on humans, their environment and mosquito habitats. Ethical concerns start with phase 2 trials, which pose limited ethical dilemmas. Phase 3 trials, which are undertaken on vulnerable civilian populations, pose ethical dilemmas ranging from individual to community concerns. It is argued that such trials must abide by established ethical principles especially safety, which is mainly enshrined in the principle of non-maleficence. As there is total lack of experience with many of the promising candidate tools (eg genetically modified mosquitoes, entomopathogenic fungi, and biocontrol agents), great caution must be exercised before they are introduced in the field. Since malaria vector trials, especially phase 3 are intrusive and in large populations, individual and community respect is mandatory, and must give great priority to community engagement. It is concluded that new tools must be safe, beneficial, efficacious, effective, and acceptable to large populations in the short and long-term, and that research benefits should be equitably distributed to all who bear the brunt of the research burdens. It is further concluded that individual and institutional capacity strengthening should be provided, in order to undertake essential research, carry out scientific and ethical review, and establish competent regulatory frameworks. PMID:21144083

2010-01-01

374

The Ultimate Buzz Kill Mosquito Control  

E-print Network

adult mosquitoes will not hide there. Make sure ornamental ponds have fish that will feed on mosquito, and porches tightly sealed and insect screens in good repair. Mosquitoes that do enter the home can

Johnson, Eric E.

375

Blood feeding patterns of mosquitoes: random or structured?  

PubMed Central

Background The foraging behavior of blood-sucking arthropods is the defining biological event shaping the transmission cycle of vector-borne parasites. It is also a phenomenon that pertains to the realm of community ecology, since blood-feeding patterns of vectors can occur across a community of vertebrate hosts. Although great advances in knowledge of the genetic basis for blood-feeding choices have been reported for selected vector species, little is known about the role of community composition of vertebrate hosts in determining such patterns. Methods & Results Here, we present an analysis of feeding patterns of vectors across a variety of locations, looking at foraging patterns of communities of mosquitoes, across communities of hosts primarily comprised of mammals and birds. Using null models of species co-occurrence, which do not require ancillary information about host abundance, we found that blood-feeding patterns were aggregated in studies from multiple sites, but random in studies from a single site. This combination of results supports the idea that mosquito species in a community may rely primarily on host availability in a given landscape, and that contacts with specific hosts will be influenced more by the presence/absence of hosts than by innate mosquito choices. This observation stresses the importance of blood-feeding plasticity as a key trait explaining the emergence of many zoonotic mosquito transmitted diseases. Discussion From an epidemiological perspective our observations support the idea that phenomena promoting synchronization of vectors and hosts can promote the emergence of vector-borne zoonotic diseases, as suggested by observations on the linkages between deforestation and the emergence of several human diseases. PMID:20205866

2010-01-01

376

A Visit to Florida's Mosquito Man  

NSDL National Science Digital Library

This radio broadcast features an interview with George O'Meara, the world's foremost expert on mosquitoes, who studies mosquito biology and dispenses fun facts (such as: only female mosquitoes bite). There are descriptions of the most aggressive mosquito species, how to tell female mosquitoes from males, and a discussion of landing rates of mosquitoes in the Everglades National Park. The clip is 5 minutes and 30 seconds in length.

2010-10-01

377

Human-to-mosquito transmission efficiency increases as malaria is controlled  

PubMed Central

The efficiency of malaria transmission between human and mosquito has been shown to be influenced by many factors in the laboratory, although their impact in the field and how this changes with disease endemicity are unknown. Here we estimate how humanmosquito transmission changed as malaria was controlled in Dielmo, Senegal. Mathematical models were fit to data collected between 1990 and the start of vector control in 2008. Results show that asexual parasite slide prevalence in humans has reduced from 70 to 20%, but that the proportion of infectious mosquitoes has remained roughly constant. Evidence suggests that this is due to an increase in transmission efficiency caused by a rise in gametocyte densities, although the uneven distribution of mosquito bites between hosts could also contribute. The resilience of mosquito infection to changes in endemicity will have important implications for planning disease control, and the development and deployment of transmission-reducing interventions. PMID:25597498

Churcher, Thomas S.; Trape, Jean-Franois; Cohuet, Anna

2015-01-01

378

Genome sequence of Anopheles sinensis provides insight into genetics basis of mosquito competence for malaria parasites  

PubMed Central

Background Anopheles sinensis is an important mosquito vector of Plasmodium vivax, which is the most frequent and widely distributed cause of recurring malaria throughout Asia, and particularly in China, Korea, and Japan. Results We performed 454 next-generation sequencing and obtained a draft sequence of A. sinensis assembled into scaffolds spanning 220.8 million base pairs. Analysis of this genome sequence, we observed expansion and contraction of several immune-related gene families in anopheline relative to culicine mosquito species. These differences suggest that species-specific immune responses to Plasmodium invasion underpin the biological differences in susceptibility to Plasmodium infection that characterize these two mosquito subfamilies. Conclusions The A. sinensis genome produced in this study, provides an important resource for analyzing the genetic basis of susceptibility and resistance of mosquitoes to Plasmodium parasites research which will ultimately facilitate the design of urgently needed interventions against this debilitating mosquito-borne disease. PMID:24438588

2014-01-01

379

Human-to-mosquito transmission efficiency increases as malaria is controlled.  

PubMed

The efficiency of malaria transmission between human and mosquito has been shown to be influenced by many factors in the laboratory, although their impact in the field and how this changes with disease endemicity are unknown. Here we estimate how human-mosquito transmission changed as malaria was controlled in Dielmo, Senegal. Mathematical models were fit to data collected between 1990 and the start of vector control in 2008. Results show that asexual parasite slide prevalence in humans has reduced from 70 to 20%, but that the proportion of infectious mosquitoes has remained roughly constant. Evidence suggests that this is due to an increase in transmission efficiency caused by a rise in gametocyte densities, although the uneven distribution of mosquito bites between hosts could also contribute. The resilience of mosquito infection to changes in endemicity will have important implications for planning disease control, and the development and deployment of transmission-reducing interventions. PMID:25597498

Churcher, Thomas S; Trape, Jean-Franois; Cohuet, Anna

2015-01-01

380

European Surveillance for West Nile Virus in Mosquito Populations  

PubMed Central

A wide range of arthropod-borne viruses threaten both human and animal health either through their presence in Europe or through risk of introduction. Prominent among these is West Nile virus (WNV), primarily an avian virus, which has caused multiple outbreaks associated with human and equine mortality. Endemic outbreaks of West Nile fever have been reported in Italy, Greece, France, Romania, Hungary, Russia and Spain, with further spread expected. Most outbreaks in Western Europe have been due to infection with WNV Lineage 1. In Eastern Europe WNV Lineage 2 has been responsible for human and bird mortality, particularly in Greece, which has experienced extensive outbreaks over three consecutive years. Italy has experienced co-circulation with both virus lineages. The ability to manage this threat in a cost-effective way is dependent on early detection. Targeted surveillance for pathogens within mosquito populations offers the ability to detect viruses prior to their emergence in livestock, equine species or human populations. In addition, it can establish a baseline of mosquito-borne virus activity and allow monitoring of change to this over time. Early detection offers the opportunity to raise disease awareness, initiate vector control and preventative vaccination, now available for horses, and encourage personal protection against mosquito bites. This would have major benefits through financial savings and reduction in equid morbidity/mortality. However, effective surveillance that predicts virus outbreaks is challenged by a range of factors including limited resources, variation in mosquito capture rates (too few or too many), difficulties in mosquito identification, often reliant on specialist entomologists, and the sensitive, rapid detection of viruses in mosquito pools. Surveillance for WNV and other arboviruses within mosquito populations varies between European countries in the extent and focus of the surveillance. This study reviews the current status of WNV in mosquito populations across Europe and how this is informing our understanding of virus epidemiology. Key findings such as detection of virus, presence of vector species and invasive mosquito species are summarized, and some of the difficulties encountered when applying a cost-effective surveillance programme are highlighted. PMID:24157510

Engler, Olivier; Savini, Giovanni; Papa, Anna; Figuerola, Jordi; Groschup, Martin H.; Kampen, Helge; Medlock, Jolyon; Vaux, Alexander; Wilson, Anthony J.; Werner, Doreen; Jst, Hanna; Goffredo, Maria; Capelli, Gioia; Federici, Valentina; Tonolla, Mauro; Patocchi, Nicola; Flacio, Eleonora; Portmann, Jasmine; Rossi-Pedruzzi, Anya; Mourelatos, Spiros; Ruiz, Santiago; Vzquez, Ana; Calzolari, Mattia; Bonilauri, Paolo; Dottori, Michele; Schaffner, Francis; Mathis, Alexander; Johnson, Nicholas

2013-01-01

381

Comparison of mosquito control programs in seven urban sites in Africa, the Middle East, and the Americas  

PubMed Central

Mosquito control programs at seven urban sites in Kenya, Egypt, Israel, Costa Rica, and Trinidad are described and compared. Site-specific urban and disease characteristics, organizational diagrams, and strengths, weaknesses, obstacles and threats (SWOT) analysis tools are used to provide a descriptive assessment of each mosquito control program, and provide a comparison of the factors affecting mosquito abatement. The information for SWOT analysis is collected from surveys, focus group discussions, and personal communication. SWOT analysis identified various issues affecting the efficiency and sustainability of mosquito control operations. The main outcome of our work was the description and comparison of mosquito control operations within the context of each study sites biological, social, political, management, and economic conditions. The issues identified in this study ranged from lack of inter-sector collaboration to operational issues of mosquito control efforts. A lack of sustainable funding for mosquito control was a common problem for most sites. Many unique problems were also identified, which included lack of mosquito surveillance, lack of law enforcement, and negative consequences of human behavior. Identifying common virtues and shortcomings of mosquito control operations is useful in identifying best practices for mosquito control operations, thus leading to better control of mosquito biting and mosquito-borne disease transmission. PMID:17316882

Impoinvil, Daniel E.; Ahmad, Sajjad; Troyo, Adriana; Keating, Joseph; Githeko, Andrew K.; Mbogo, Charles M; Kibe, Lydiah; Githure, John I.; Gad, Adel M.; Hassan, Ali N.; Orshan, Laor; Warburg, Alon; Caldern-Arguedas, Olger; Snchez-Lora, Victoria M.; Velit-Suarez, Rosanna; Chadee, Dave D.; Novak, Robert J.; Beier, John C.

2007-01-01

382

Summary of lessons learned from USDA-ARS Area-Wide Asian Tiger Mosquito Management Project  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aedes albopictus, the Asian tiger mosquito, is the principal vector of chikungunya and a critical vector of dengue viruses. This daytime biting pest is now distributed over much of the eastern quadrant of the continental U.S. all the way north to coastal New York, and often causes the majority of se...

383

Rapid identification of virus-carrying mosquitoes using reverse transcription-loop-mediated isothermal amplification  

Microsoft Academic Search

Mosquitoes are critical vectors in many arboviral transmission cycles. Considering the increasing incidence of arboviral infections throughout the world, monitoring of vector populations for the presence of an arbovirus could be considered an important initial step of risk assessment to humans and animals. In response to this need, increased efforts to develop rapid and reliable diagnostic techniques have been undertaken;

Namal Perera; Hiroka Aonuma; Aya Yoshimura; Tokiyasu Teramoto; Hiroshi Iseki; Bryce Nelson; Ikuo Igarashi; Takeshi Yagi; Shinya Fukumoto; Hirotaka Kanuka

2009-01-01

384

Distribution of African Malaria Mosquitoes Belonging to the Anopheles gambiae Complex  

Microsoft Academic Search

The distribution of malaria vector mosquitoes, especially those belonging to species complexes that contain non-vector species, is important for strategic planning of malaria control programmes. Geographical information systems have allowed researchers to visualize distribution data on maps together with environmental parameters, such as rainfall and temperature. Here, Maureen Coetzee, Marlies Craig and David le Sueur review our current knowledge on

M. Coetzee; M. Craig; D. le Sueur

2000-01-01

385

Zika Virus Emergence in Mosquitoes in Southeastern Senegal, 2011  

PubMed Central

Background Zika virus (ZIKV; genus Flavivirus, family Flaviviridae) is maintained in a zoonotic cycle between arboreal Aedes spp. mosquitoes and nonhuman primates in African and Asian forests. Spillover into humans has been documented in both regions and the virus is currently responsible for a large outbreak in French Polynesia. ZIKV amplifications are frequent in southeastern Senegal but little is known about their seasonal and spatial dynamics. The aim of this paper is to describe the spatio-temporal patterns of the 2011 ZIKV amplification in southeastern Senegal. Methodology/Findings Mosquitoes were collected monthly from April to December 2011 except during July. Each evening from 18?00 to 21?00 hrs landing collections were performed by teams of 3 persons working simultaneously in forest (canopy and ground), savannah, agriculture, village (indoor and outdoor) and barren land cover sites. Mosquitoes were tested for virus infection by virus isolation and RT-PCR. ZIKV was detected in 31 of the 1,700 mosquito pools (11,247 mosquitoes) tested: Ae. furcifer (5), Ae. luteocephalus (5), Ae. africanus (5), Ae. vittatus (3), Ae. taylori, Ae. dalzieli, Ae. hirsutus and Ae. metallicus (2 each) and Ae. aegypti, Ae. unilinaetus, Ma. uniformis, Cx. perfuscus and An. coustani (1 pool each) collected in June (3), September (10), October (11), November (6) and December (1). ZIKV was detected from mosquitoes collected in all land cover classes except indoor locations within villages. The virus was detected in only one of the ten villages investigated. Conclusions/Significance This ZIKV amplification was widespread in the Kdougou area, involved several mosquito species as probable vectors, and encompassed all investigated land cover classes except indoor locations within villages. Aedes furcifer males and Aedes vittatus were found infected within a village, thus these species are probably involved in the transmission of Zika virus to humans in this environment. PMID:25310102

Diallo, Diawo; Sall, Amadou A.; Diagne, Cheikh T.; Faye, Oumar; Faye, Ousmane; Ba, Yamar; Hanley, Kathryn A.; Buenemann, Michaela; Weaver, Scott C.; Diallo, Mawlouth

2014-01-01

386

Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies  

PubMed Central

Background When rhesus monkeys (Macaca mulatta) are used to test malaria vaccines, animals are often challenged by the intravenous injection of sporozoites. However, natural exposure to malaria comes via mosquito bite, and antibodies can neutralize sporozoites as they traverse the skin. Thus, intravenous injection may not fairly assess humoral immunity from anti-sporozoite malaria vaccines. To better assess malaria vaccines in rhesus, a method to challenge large numbers of monkeys by mosquito bite was developed. Methods Several species and strains of mosquitoes were tested for their ability to produce Plasmodium knowlesi sporozoites. Donor monkey parasitaemia effects on oocyst and sporozoite numbers and mosquito mortality were documented. Methylparaben added to mosquito feed was tested to improve mosquito survival. To determine the number of bites needed to infect a monkey, animals were exposed to various numbers of P. knowlesi-infected mosquitoes. Finally, P. knowlesi-infected mosquitoes were used to challenge 17 monkeys in a malaria vaccine trial, and the effect of number of infectious bites on monkey parasitaemia was documented. Results Anopheles dirus, Anopheles crascens, and Anopheles dirus X (a cross between the two species) produced large numbers of P. knowlesi sporozoites. Mosquito survival to day 14, when sporozoites fill the salivary glands, averaged only 32% when donor monkeys had a parasitaemia above 2%. However, when donor monkey parasitaemia was below 2%, mosquitoes survived twice as well and contained ample sporozoites in their salivary glands. Adding methylparaben to sugar solutions did not improve survival of infected mosquitoes. Plasmodium knowlesi was very infectious, with all monkeys developing blood stage infections if one or more infected mosquitoes successfully fed. There was also a dose-response, with monkeys that received higher numbers of infected mosquito bites developing malaria sooner. Conclusions Anopheles dirus, An. crascens and a cross between these two species all were excellent vectors for P. knowlesi. High donor monkey parasitaemia was associated with poor mosquito survival. A single infected mosquito bite is likely sufficient to infect a monkey with P. knowlesi. It is possible to efficiently challenge large groups of monkeys by mosquito bite, which will be useful for P. knowlesi vaccine studies. PMID:24893777

2014-01-01

387

Antibiotics in ingested human blood affect the mosquito microbiota and capacity to transmit malaria.  

PubMed

Malaria reduction is most efficiently achieved by vector control whereby human populations at high risk of contracting and transmitting the disease are protected from mosquito bites. Here, we identify the presence of antibiotics in the blood of malaria-infected people as a new risk of increasing disease transmission. We show that antibiotics in ingested blood enhance the susceptibility of Anopheles gambiae mosquitoes to malaria infection by disturbing their gut microbiota. This effect is confirmed in a semi-natural setting by feeding mosquitoes with blood of children naturally infected with Plasmodium falciparum. Antibiotic exposure additionally increases mosquito survival and fecundity, which are known to augment vectorial capacity. These findings suggest that malaria transmission may be exacerbated in areas of high antibiotic usage, and that regions targeted by mass drug administration programs against communicable diseases may necessitate increased vector control. PMID:25562286

Gendrin, Mathilde; Rodgers, Faye H; Yerbanga, Rakiswend S; Oudraogo, Jean Bosco; Basez, Mara-Gloria; Cohuet, Anna; Christophides, George K

2015-01-01

388

Infection of Laboratory-Colonized Anopheles darlingi Mosquitoes by Plasmodium vivax  

PubMed Central

Anopheles darlingi Root is the most important malaria vector in the Amazonia region of South America. However, continuous propagation of An. darlingi in the laboratory has been elusive, limiting entomological, genetic/genomic, and vectorpathogen interaction studies of this mosquito species. Here, we report the establishment of an An. darlingi colony derived from wild-caught mosquitoes obtained in the northeastern Peruvian Amazon region of Iquitos in the Loreto Department. We show that the numbers of eggs, larvae, pupae, and adults continue to rise at least to the F6 generation. Comparison of feeding Plasmodium vivax ex vivo of F4 and F5 to F1 generation mosquitoes showed the comparable presence of oocysts and sporozoites, with numbers that corresponded to blood-stage asexual parasitemia and gametocytemia, confirming P. vivax vectorial capacity in the colonized mosquitoes. These results provide new avenues for research on An. darlingi biology and study of An. darlingiPlasmodium interactions. PMID:24534811

Moreno, Marta; Tong, Carlos; Guzmn, Mitchel; Chuquiyauri, Raul; Llanos-Cuentas, Alejandro; Rodriguez, Hugo; Gamboa, Dionicia; Meister, Stephan; Winzeler, Elizabeth A.; Maguina, Paula; Conn, Jan E.; Vinetz, Joseph M.

2014-01-01

389

Transcriptome response to pollutants and insecticides in the dengue vector Aedes aegypti using next-generation sequencing technology  

PubMed Central

Background The control of mosquitoes transmitting infectious diseases relies mainly on the use of chemical insecticides. However, mosquito control programs are now threatened by the emergence of insecticide resistance. Hitherto, most research efforts have been focused on elucidating the molecular basis of inherited resistance. Less attention has been paid to the short-term response of mosquitoes to insecticides and pollutants which could have a significant impact on insecticide efficacy. Here, a combination of LongSAGE and Solexa sequencing was used to perform a deep transcriptome analysis of larvae of the dengue vector Aedes aegypti exposed for 48 h to sub-lethal doses of three chemical insecticides and three anthropogenic pollutants. Results Thirty millions 20 bp cDNA tags were sequenced, mapped to the mosquito genome and clustered, representing 6850 known genes and 4868 additional clusters not located within predicted genes. Mosquitoes exposed to insecticides or anthropogenic pollutants showed considerable modifications of their transcriptome. Genes encoding cuticular proteins, transporters, and enzymes involved in the mitochondrial respiratory chain and detoxification processes were particularly affected. Genes and molecular mechanisms potentially involved in xenobiotic response and insecticide tolerance were identified. Conclusions The method used in the present study appears as a powerful approach for investigating fine transcriptome variations in genome-sequenced organisms and can provide useful informations for the detection of novel transcripts. At the biological level, despite low concentrations and no apparent phenotypic effects, the significant impact of these xenobiotics on mosquito transcriptomes raise important questions about the 'hidden impact' of anthropogenic pollutants on ecosystems and consequences on vector control. PMID:20356352

2010-01-01

390

Rutgers University: New Jersey Mosquito Homepage-Mosquito Biology  

NSDL National Science Digital Library

As the weather warms and the pre-summer rains fall, the familiar buzz of the mosquito can be heard in our ears. This website from entomologists at Rutgers University provides a nice overview of Mosquito Biology including sections on Life Cycle, Anatomy, Habitats, and Behavior. The site also includes some New Jersey-specific sections such as A Classification System for the Life Cycles of Mosquitoes in New Jersey, a fact sheet about the Asian Tiger Mosquito in New Jersey, a Morphological Comparison of Ochlerotatus Species in New Jersey, and a New Jersey Species List. The Species List contains profiles for 63 species of mosquitoes found in New Jersey, and provides information about their geographic distribution, larval habitat, larval identification, anatomical features, and more.