Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Mosquito Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed1961

Investigation into the problem of insecticide sorption by soils.

In view of the importance of the problem of insecticide sorption by certain soils, and its possible implications for mosquito control, an investigation was carried out on the influence of some factors governing sorption.In experiments with thin layers of homogenized soil/insecticide mixtures, in which no diffusion took place, changes in relative humidity had a pronounced influence on the effectiveness of the insecticide, a 10% increase in humidity doubling the toxicity. Further experiments using DDT labelled with (14)C showed that the effect of humidity was the only factor influencing toxicity.Studies with (14)C DDT and bio-assay determination of non-labelled DDT and dieldrin showed that movement of the insecticide in the soil was blocked at both very high and very low humidity, and that inward migration was found only at intermediate humidities. It was also observed that the migration of water in the soil caused the insecticide to move in the same direction.As at a high relative humidity the inward migration of the insecticide is blocked, and as the initial loss in effectiveness by sorption is counterbalanced by the greater availability of the remaining toxicant, the application of the usual field dosage of dieldrin (0.5 g/m(2)) remained effective for a considerable period. This would suggest that sorption might well be a problem in the field only when humidity is low. In work on means of reducing sorption under dry conditions, encouraging results were obtained with wettable powders based on ground solidified melts of dieldrin and certain resins.

Insecticides↗
PubMed2002

Larvicidal activity of latex and stem bark of Euphorbia tirucalli plant on the mosquito Culex quinquefasciatus.

The methanolic, chloroform and ether extracts of Euphorbia tirucalli latex and stem bark were evaluated for larvicidal activity against laboratory-reared larvae of Culex quinquefasciatus (Diptera: Culicidae), vector of the brancroftian filariasis and worst urban nuisance mosquito. The latex extracts contain more potent larvicidal components (177.14 mg/L-326.37 mg/L) than the stem bark extracts (237.663 mg/L-513.39 mg/L). The order of toxicity (LC50) for the latex extracts was Methanol extract (177.14 mg/L) > Chloroform (200.76 mg/L) > Ether (326.37 mg/L) while the rank of order of toxicity (LC50) of stem bark extracts was Ether (237.66 mg/L) > Chloroform (343.515 mg/L) > Methanol (513.387 mg/L), Higher doses (LC90 24 h of mosquito larvae) of each extract did not cause any mortality among fishes after 24 h. The study gave a weight into the possibility of formulating suitable preparation from the latex and stem bark extracts of the plant for use in mosquito control programme.

Animals↗
PubMed2004

Diagnostic dose of synergized d-phenothrin for insecticide susceptibility testing by bottle bioassay.

The diagnostic dose of d-phenothrin synergized 1:1 with piperonyl butoxide for testing insecticide susceptibility of mosquitoes by bottle bioassay is reported for 2 mosquito species, Culex quinquefasciatus and Ochlerotatus taeniorhynchus. The diagnostic dose was defined as 2 times the 95% lethal concentration (LC95). LC50, LC90, and LC95 were estimated by probit analysis of dose response data. Procedures for diluting the commercial-grade off-the-shelf pesticide in acetone, treating the bottles, and calculating baseline data for insecticide-susceptible mosquito populations are described. The advantages and disadvantages of testing off-the-shelf commercial-grade pesticides that are maintained on premises by mosquito control programs, in contrast to using reagent-grade chemicals purchased from a chemical supply house, are also discussed. Data obtained by this method can be invaluable in making timely management decisions about the choice of pesticides in a control program.

Animals↗
PubMed2004

Laboratory evaluation of the predation efficacy of native Australian fish on Culex annulirostris (Diptera: Culicidae).

The introduction and establishment of fish populations can provide long-term, cost-effective mosquito control in habitats such as constructed wetlands and ornamental lakes. The predation efficacy of 7 native Brisbane freshwater fish on 1st and 4th instars of the freshwater arbovirus vector Culex annulirostris was evaluated in a series of 24-h laboratory trials. The trials were conducted in 30-liter plastic carboys at 25+/-1 degrees C under a light:dark cycle of 14:10 h. The predation efficacy of native crimson-spotted rainbowfish Melanotaenia duboulayi (Melanotaeniidae), Australian smelt Retropinna semoni (Retropinnadae), Pacific blue-eye Pseudomugil signifer (Atherinidae), fly-specked hardyhead Craterocephalus stercusmuscarum (Atherinidae), firetail gudgeon Hypseleotris galii (Eleotridae), empire gudgeon Hypseleotris compressa (Eleotridae), and estuary perchlet Ambassis marianus (Ambassidae) was compared with the exotic eastern mosquitofish Gambusia holbrooki (Poeciliidae). This environmentally damaging exotic has been disseminated worldwide and has been declared noxious in Queensland. Melanotaenia duboulayi was found to consume the greatest numbers of both 1st and 4th instars of Cx. annulirostris. The predation efficacy of the remaining Australian native species was comparable with that of the exotic G. holbrooki. With the exception of A. marianus, the maximum predation rates of these native species were not statistically different whether tested individually or in a school of 6. Based on these data, M. duboulayi, H. compressa, and A. marianus warrant further investigation as biological control agents in pilot field trials.

Animals↗
PubMed2005

Aedine mosquito species (Diptera: Culicidae: Aedini) occurring in Thailand with their current generic and subgeneric status, and new country records.

A list of the currently valid generic and species-level taxa of tribe Aedini in Thailand is provided. Its purpose is to enable entomologists, public health personnel and mosquito control workers to more quickly become familiar with recent formal taxonomic changes within the tribe. New country records of four species of Armigeres are reported.

Animals↗
PubMed2005

Environmental predictors of Ross River virus disease outbreaks in Queensland, Australia.

Ross River virus (RRV) disease is the most common mosquito-borne disease in Australia, with the majority of cases reported from Queensland. In this study we investigate the relationship between local RRV disease outbreaks and standardized rainfall and temperature data in Queensland. No one set of variables could be found to accurately predict RRV disease outbreaks across all of Queensland, although good predictive models could be developed for smaller regions. The variables identified as important in predicting RRV disease outbreaks differed between regions, and also between summer and autumn. This work highlights the sensitive relationship between virus prevalence, mosquito bionomics, and climate, illustrating that critical climatic factors differ depending on underlying environmental conditions. Identification of factors leading to RRV disease outbreaks will help local authorities identify periods of high risk, optimizing the provision of additional mosquito control measures.

Arbovirus Infections↗
PubMed2004

Laboratory bio-assay of temephos and fenthion against some vector species of public health importance.

Laboratory studies carried out using Temephos and Fenthion, two commonly used larvicides under Urban Malaria Scheme (NMEP) and NFCP for the control of mosquito larvae. The results revealed that the LC50 and LC90 values for temephos against Aedes aegypti 0.0177 and 0.0559, Anopheles stephensi 0.0148 and 0.0472, Culex quinquefasciatus 0.0157 & 0.0480 and for Culex vishnui group of mosquitoes 0.043 & 0.0118 ppm respectively. The results obtained revealed that there is a 62.8 & 94.12 times increase in the LC50 & LC90 of Cx. Quinquefasciatus which indicates that the species has developed resistance to temephos. There were 6.32 & 8.34 fold increase in Ae. aegypti and 2.27 & 2.34 fold increase in LC50 & LC90 values of An. stephensi are indicative of development of tolerance against temephos. Similarly LC50 and LC90 values estimated for fenthion against Ae. aegypti 0.0173 & 0.0392, An. stephensi 0.0274 & 0.0992 and Cx. quinquefasciatus 0.03 & 0.0469 respectively. The slope values were found to be higher in fenthion as compared to temephos. It was recorded to be 2.72 times higher in Cx. quinquefasciatus and 1.54 times against An. stephensi. However, much difference was not observed in the slope values of temephos and fenthion in Ae. aegypti.

Aedes↗
PubMed2006

Eastern equine encephalitis--New Hampshire and Massachusetts, August-September 2005.

During August-September 2005, the New Hampshire Department of Health and Human Services reported seven cases of human eastern equine encephalitis virus (EEEV) disease, the first laboratory-confirmed, locally acquired cases of human EEEV disease reported from New Hampshire in 41 years of national surveillance. Also during August--September 2005, the Massachusetts Department of Public Health reported four cases of human EEEV disease, five times the annual average of 0.8 cases reported from Massachusetts during the preceding 10 years. Four of the 11 patients from New Hampshire and Massachusetts died. EEEV is transmitted in marshes and swamps in an enzootic bird-mosquito-bird cycle primarily by the mosquito Culiseta melanura. Bridge mosquito vectors (e.g., Coquillettidia perturbans, Aedes vexans, or Aedes sollicitans) transmit EEEV to humans and other mammals. This report summarizes the investigations of cases in New Hampshire and Massachusetts conducted by the two state health departments and CDC. The findings underscore the importance of surveillance for, and diagnostic consideration of, arboviral encephalitis in the United States and promotion of preventive measures such as local mosquito control and use of insect repellent.

Adolescent↗
PubMed2005

Dengue vaccine.

Dengue is an expanding health problem. About two-fifths of the world population are at risk for acquiring dengue with 50-100 million cases of acute febrile illness yearly including about 500,000 cases of DHF/DSS. No antiviral drugs active against the flavivirus exist. Attempts to control mosquito vector has been largely unsuccessful. Vaccination remains the most hopeful preventive measure. Dengue vaccine has been in development for more than 30 years, yet none has been licensed. The fact that enhancing antibody from previous infection and high level of T cell activation during secondary infection contribute to immunopathology of DHF, the vaccine must be able to induce protective response to four dengue serotypes simultaneously. Inactivated vaccine is safe but needs a repeated booster thus, development is delayed. Tetravalent live attenuated vaccine and chimeric vaccine using yellow fever or dengue viruses as a backbone are being carried out in human trials. DNA vaccine and subunit vaccine are being carried out in animal trials.

Dengue↗
PubMed2006

Clinical presentations and laboratory findings in suspected cases of dengue virus.

OBJECTIVE: To study the clinical presentations and laboratory findings of patients presented with fever in a Hospital in Portsudan, Sudan and to detect dengue virus antibodies in their blood. METHODS: This study was carried in Almwani Hospital during the period from April to July 2005. Eighty-four patients were included in this hospital-based study. All of them had fever. Their blood films, Widal tests for typhoid, stools and urine investigations were normal. The clinical data were collected using questionnaires. Two samples of blood were taken. One was for general hematological investigation (white blood cell and platelets count), while serum was taken from the other sample for serological detection of the dengue virus antibodies using the enzyme-linked immunosorbent assay (ELISA) technique. RESULTS: The fever was associated with vomiting (22 patients) and abdominal pain (44 patients). In 93% of the cases bleeding (epistaxes, purpura, malena, hematemesis, and others) occurred. Routine laboratory findings were leucopenia (90% of the cases) and thrombocytopenia (88% of the cases). The diagnosis was confirmed by ELISA detection of dengue virus immunoglobulin M antibodies (in 88% of the patient's sera). CONCLUSION: In endemic areas with mosquitoes such as Aedes aegypti, infection with dengue virus should highly be suspected in patients presented with fever. The ELISA or rapid tests for detection of the viral antibodies should be added to the routine investigations to any patient with complain of fever with no obvious cause. Surveillance program and mosquito control measures should be activated in Portsudan.

Adolescent↗
PubMedDate not supplied

Seroprevalence of West Nile virus in Saskatchewan's Five Hills Health Region, 2003.

BACKGROUND: The Five Hills Health Region of Saskatchewan reported the highest West Nile virus (WNV) case rates in the 2003 outbreak. A serologic and telephone survey was undertaken to assess the seroprevalence of the virus and the knowledge, attitudes and behaviours of the residents. METHODS: Respondents had to be at least 18 years of age, and residents of the Five Hills Health Region between July 1st and September 15th, 2003. Blood samples of respondents were tested at the National Microbiology Laboratory for flavivirus immunoglobulin using a WNV IgG ELISA and plaque reduction neutralization test. Descriptive analyses performed related to respondents' demographics, knowledge, attitudes, behaviours, and seropositivity. WNV infection risk was assessed using odds ratio. RESULTS: There were 619 questionnaire respondents, of whom 501 donated a blood sample. The seroprevalence of WNV in the Five Hills Health Region was 9.98% (95% CI 7.37-12.59%). Seropositivity of rural areas was 16.8% and urban was 3.2%. Most (97%) of participants thought WNV was an important health issue. Forty-eight percent of the participants used insect repellents containing DEET most of the time. There was good knowledge regarding WNV transmission and prevention of the spread of WNV. Rural compared to urban residents were six times more likely to be positive for WNV (OR=6.13, 95% CI 2.82-13.34). INTERPRETATION: This is the highest seroprevalence rate of West Nile virus recorded in North America thus far. Many factors could have influenced this outbreak, such as eco-region, early prolonged hot weather, level of mosquito control programs, urban and rural community differences, and personal protective behaviours.

Adolescent↗
PubMed2005

[Efficient and permanent impact of two insecticides with the active ingredient, temephos, on mosquitoes (Diptera: Culicidae) larvae.].

The efficiency of two insecticides with the active ingredient, temephos (Tambro(R) 500 EC and Ekolarv(R) 500 EC), in laboratory and field conditions on Anopheles sacharovi Favre, and Culex pipiens (Linnaeus) larvae has been determined. Under laboratory conditions, it has been determined that both species are sensitive to insecticides. Under field conditions, 100% of larval mortality has been found even with the lowest (0.05 l/ha) of insecticide doses. It has been found that there was no difference in permanence of the effect of insecticides and their doses (p > 0.05). It has been found that insecticides used in mosquito control which contain the active ingredient temephos have to be used for a 20 day period under central Anatolia conditions.

English Abstract↗
PubMed1991

Culture of Gambusia affinis with food fishes.

Culture of Gambusia affinis along with carps in fish culture practice in village ponds in Shahjahanpur distt., U.P., has revealed very little difference in fish productivity (1539 kg/ha in ponds with Gambusia, 1572 kg/ha in ponds without Gambusia). The growth and survival of Gambusia were found to be good in most of the composite fish culture ponds. Culture of Gambusia along with edible fish in village ponds is, therefore, recommended to get the dual benefit of fish production and control of mosquito proliferation in village ponds.

Animals↗
PubMed1990

[Malaria situation in China, 1989. Advisory Committee on Parasitic Diseases, MOPH].

According to the case reporting system, malaria cases in the whole country (Taiwan Province not included) in 1989 accounted for 137,540, the incidence being 12.56/100,000, and lethal cases, 60. All these were close to those (134,156, 12.44/100,000, and 53) in 1988, while an insidious increase was in view. On the basis of county/city reckoning, about 984.5 million people reside in 2,576 counties/cities where malaria incidence was less than 0.1 per 1,000 (including non-endemic areas); 80.2 million people in 174 counties/cities with incidence of 0.1-1.0 per 1,000; 29.9 million people in 76 counties/cities with incidence of 1.1-10 per 1,000; and 500,000 people in 5 counties with an incidence above 10 per 1,000. Though malaria incidence in the whole nation continued to decline to some extent, informations from 3 provinces, i.e. southern Yunnan, Sichuan and middle Anhui showed an increase of 18.26%, 33.02% and 33.91% respectively, as compared with the incidence in 1988. This was due to incomplete implementation of malaria intervention strategies and the decrease in mosquito control areas. The general situation could be summarized as follows: in endemic areas with Anopheles sinensis as vector, the malaria incidence was steadily decreasing, malaria cases were few and scattered with the proportion of exogenous cases increasing; whereas in areas with A. anthropophagus, A. minimus and A. dirus as vectors, the prevalence was unstable and focal outbreaks often occurred. Such places were the main endemic areas of malaria. The endemic areas of falciparum malaria covered 69 counties of 5 provinces/autonomous region, while non-indigenous falciparum cases were reported from 73 counties of 8 provinces/municipality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[First detection of Anopheles species mosquitoes breeding in water-filled cellars].

Studies of the breeding of blood-sucking mosquitos in water-filled cellars of Astrakhan were carried out in 1980-1986 using routine entomological techniques of assessment, collection and determination of blood-sucking mosquitos. In July, 1986, Anopheles sp. breeding in the cellars of 2 multistory buildings was registered along with commonly observed breeding of C. pipiens. The rate of preimago development stages of Anopheles sp. was 2 to 10 sp. per 1 cubic meter of water surface. Water-filled cellars are full of ground water mixed with sewage. It increases epidemiological value of the fact of mosquitos' breeding in populated areas, which should be taken into account during mosquito control.

Animals↗
PubMed1987

Comparative larvivorous performances of mosquitofish, Gambusia affinis, and juvenile Sacramento blackfish, Orthodon microlepidotus, in experimental paddies.

Mosquitofish, Sacramento blackfish, or combinations of both species were stocked in experimental paddies. Cultured Culex tarsalis larvae, stocked weekly into each paddy, and wild Anopheles freeborni larvae were counted by dipping. At the end of the 12 week experiment, paddies were drained and the remaining fish and visible invertebrates counted. Data show the highest number of mosquito larvae in the blackfish-stocked paddies. This low larvivorous ability of blackfish may result from their rapid growth to ca. 70 mm standard length and a consequent shift to a filtering mode of feeding. Although blackfish populations decreased from one-third to one-half of their stocked levels and mosquitofish populations increased to very high levels, mosquito control seemed to be a function of species rather than just the number of predatory fish. The lower number of larvae in the control paddies compared with the blackfish paddies might be attributable to predatory invertebrate communities.

Agriculture↗