| regulation of swimming in the culex pipiens (diptera, culicidae) pupa: kinematics and locomotory trajectories. | high-speed videography was used to investigate swimming kinematics and locomotory trajectories during escape responses in the pupa of culex pipiens (diptera, culicidae). the pupa can perform straight-line motion despite undergoing backward and forward somersaults through 400 degrees at a rate of 20 s(-)(1). for linear motion to occur, the effective stroke of the abdomen must be delivered during the part of each cycle when the body is facing forwards, allowing passive rotation to carry the body r ... | 1999 | 10460739 |
| attraction of culex pipiens pipiens (diptera: culicidae) to flower volatiles. | methylene chloride extracts of flowers from 4 plants (common milkweed, asclepias syriaca l; ox-eye daisy, leucanthemum vulgare lamarck; canada goldenrod, solidago canadensis l.; and yarrow, achillea millefolium l.) were tested in a dual-port olfactometer for attractiveness to female northern house mosquitoes, culex pipiens pipiens l. fifty milligrams of extract was used for each test, which was equivalent to the amount of extract from flowers of 0.58 common milkweed inflorescences, 1.75 ox-eye d ... | 1999 | 10467780 |
| [an experimental model to analyse the characteristics of a strain of culex pipiens and its sensitivity to insecticides]. | this study, based on phenotype of green larvae colour, has enabled the selection of a genetically distinct line of culex pipiens pipiens. the four loci under study were found to be homozygous to the 42nd generation. these loci were associated with an increased sensitivity to organochlorides in the progeny when compared to the parent strain. this observation, with possible expansion to other species, has potential practical applications in the identification of susceptible insect populations in i ... | 1999 | 10472450 |
| tracking the evolution of insecticide resistance in the mosquito culex pipiens. | the evolution of pesticide resistance provides some of the most striking examples of darwinian evolution occurring over a human life span. identification of resistance alleles opens an outstanding framework in which to study the evolution of adaptive mutations from the beginning of pesticide application, the evolution of interactions between alleles (dominance) or between loci (epistasis). here we show that resistance alleles can also be used as markers to dissect population processes at a micro ... | 1999 | 10476962 |
| residual activity of bacillus thuringiensis serovars medellin and jegathesan on culex pipiens and aedes aegypti larvae. | bacillus thuringiensis serovar medellin strain 163-131 and bacillus thuringiensis serovar jegathesan (b.t.jeg.) strain 367 are very toxic to mosquito larvae. however, they are 10 times less toxic than bacillus thuringiensis var. israelensis (b.t.i.) to mosquito larvae under laboratory conditions. lyophilized powders were produced from these strains and their toxicities were compared to that of powder produced from the b.t.i. strain. larvicidal activity was titrated using aedes aegypti (bora-bora ... | 1999 | 10480130 |
| genetic reassortment of rift valley fever virus in nature. | rift valley fever virus (rvfv), a phlebovirus of the bunyaviridae family, is an arthropod-borne virus which emerges periodically throughout africa, emphasizing that it poses a major threat for animal and human populations. to assess the genetic variability of rvfv, several isolates from diverse localities of africa were investigated by means of reverse transcription-pcr followed by direct sequencing of a region of the small (s), medium (m), and large (l) genomic segments. phylogenetic analysis s ... | 1999 | 10482570 |
| [surveillance of mosquito-borne viruses in breclav after the flood of 1997]. | in july 1997, devastating floods occurred after heavy rains in moravia, czech republic. mosquito populations increased abruptly in the flooded area thereafter. we carried out a surveillance for mosquito-borne virus infections in the breclav area, south moravia, including serosurveys of inhabitants. a total of 11,334 female mosquitoes in 117 pools (9,100 aedes vexans, 917 a. cinereus, 11 a. cantans, 1,074 a. sticticus and 232 culex pipiens pipiens) were examined by virological methods. seven viru ... | 1999 | 10528440 |
| entomologic and avian investigations of an epidemic of west nile fever in romania in 1996, with serologic and molecular characterization of a virus isolate from mosquitoes. | between july and october 1996, a west nile (wn) fever epidemic occurred in the southern plain and danube valley of romania and in the capital city of bucharest, resulting in hundreds of neurologic cases and 17 fatalities. in early october 1996, entomologic and avian investigations of the epidemic were conducted in the city of bucharest and nearby rural areas. thirty (41%) of 73 domestic fowl sampled had neutralizing antibody to wn virus, including 5 of 13 ducks (38%), 1 of 1 goose, 19 of 52 chic ... | 1999 | 10548295 |
| juvenile hormone analogs active on mosquitoes: synthesis and juvenile hormonal activity of newly synthesized long chain alkoxy alkyl phenyl ethers. | different 2-(8,12 dimethyl-5-oxa-7(e), 11-tridecadienyl)-alkyl phenyl ethers, their mono oxirane and thirane derivatives were synthesized and tested on culex pipiens quinquefasciatus say for their juvenile hormone activity. | 1999 | 10549579 |
| new esterase enzymes involved in organophosphate resistance in culex pipiens (diptera: culicidae) from guang zhou, china. | organophosphate (op) insecticides have been used widely to control culex pipiens l. populations and this has led to the emergence of op-resistance. predominantly, resistance in cx. pipiens is caused by over-production of nonspecific esterases, such as est beta 1(1) and est alpha 2(1)/beta 2(1). these esterases confer multiple resistance to organophosphorus and carbamate insecticides. to define the esterases in chinese cx. pipiens, restriction fragment-length polymorphism analysis was performed a ... | 1999 | 10593064 |
| host feeding of mosquitoes (diptera: culicidae) associated with the recurrence of rift valley fever in egypt. | in 1993, rift valley fever (rvf) virus reappeared in egypt. we determined the prevalence and feeding patterns of mosquitoes in 5 villages where the virus was active. of 10 species recovered, aedes caspius (pallas), culex pipiens l., cx. antennatus (becker), and cx. perexiguus theobald constituted 99% of > 35,000 mosquitoes captured in dry ice-baited cdc light traps. ae. caspius was most prevalent, except at nag' el hagar where it was replaced by cx. perexiguus. cx. pipiens ranked 2nd, except at ... | 1999 | 10593070 |
| a new mechanism conferring unprecedented high resistance to chlorpyrifos in culex pipiens (diptera: culicidae). | the cause of high resistance to chlorpyrifos observed in tunisian culex pipiens (l.) was investigated by comparing a tunisian strain g (> 10,000-fold resistance), a french strain t (approximately 50-fold resistance), and a susceptible reference strain s. strains g and t had the same level of propoxur resistance (approximately 1,000-fold) and were homozygous for an autosomal propoux-insensitive acetylcholinesterase (ache-1). in g and t strains, as well as in the offspring of different f1s and bac ... | 1999 | 10593083 |
| isolation of west nile virus from mosquitoes, crows, and a cooper's hawk in connecticut. | west nile (wn) virus, a mosquito-transmitted virus native to africa, asia, and europe, was isolated from two species of mosquitoes, culex pipiens and aedes vexans, and from brain tissues of 28 american crows, corvus brachyrhynchos, and one cooper's hawk, accipiter cooperii, in connecticut. a portion of the genome of virus isolates from four different hosts was sequenced and analyzed by comparative phylogenetic analysis. our isolates from connecticut were similar to one another and most closely r ... | 1999 | 10600741 |
| the larvicidal activities of the peel oils of three citrus fruits against culex pipiens. | the larviciddal action of three ethanol extracts of peel oils of lemon, grapefruit and navel orange were tested against the early 4th instar larvae of culex pipiens and the resulting pupae. the lc50 were 18.5, 20.3 and 26.5 and the slope functions were 2.9, 2.9 and 3.9 respectively. the action of the lemon extract extended to the pupae which resulted from larvae exposed to sublethal dose. some of the pupae were unable to escape from the larval exuviae. | 1999 | 10605488 |
| total salivary gland proteins of female culex pipiens and aedes caspius (diptera: culicidae) and their fractionation during adult development and after blood sucking. | salivary glands of culex pipiens and aedes caspius were analyzed to determine total protein content and its fractionation during adult female development and after blood sucking. in both species, the molecular weight of proteins ranged between 26.000 and 84.000 daltons. these proteins were not identical in the two species. in cx. pipiens, the total protein level increased during the first 3 days of adult development from 4.94 +/- 0.84 to 6.6 +/- 0.37 micrograms/gland. during this period, the sal ... | 1999 | 10605511 |
| the s segment of rift valley fever phlebovirus (bunyaviridae) carries determinants for attenuation and virulence in mice. | unlike all the other rift valley fever virus strains (bunyaviridae, phlebovirus) studied so far, clone 13, a naturally attenuated virus, does not form the filaments composed of the nss nonstructural protein in the nuclei of infected cells (r. muller, j. f. saluzzo, n. lopez, t. drier, m. turell, j. smith, and m. bouloy, am. j. trop. med. hyg. 53:405-411, 1995). this defect is correlated with a large in-frame deletion in the nss coding region of the s segment of the tripartite genome. here, we sh ... | 2000 | 10627566 |
| differential toxicity of leaf litter to dipteran larvae of mosquito developmental sites. | the relative toxicity of leaf litter to nematocerous dipteran larvae characteristic of mosquito developmental sites was investigated. culicidae, chironomidae, and simuliidae taxa originating from alpine hydrosystems were tested together with two laboratory nonindigenous culicid taxa. bioassays indicate that ingestion of 10-month-old decaying leaves from alnus glutinosa, populus nigra, and quercus robur by larvae is more deleterious for aedes aegypti, a. albopictus, culex pipiens, simulium varieg ... | 2000 | 10631052 |
| analysis of clines with variable selection and variable migration. | we report a likelihood-based method that estimates both dispersal and natural selection using the rate of change of the shape of a cline when selection and migration are not constant through time. we have investigated the case of local adaptation of the mosquito culex pipiens to organophosphate insecticides in the montpellier area in france. we have analyzed the modification of the clinal patterns at two resistance loci during the period from breeding to overwintering. we show that mosquitoes mi ... | 2000 | 10657178 |
| occurrence of bacillus thuringiensis in fresh waters of japan. | bacillus thuringiensis was recovered at a relatively high frequency from both running and still fresh waters in natural environments of kyushu, japan. of 107 water samples examined, 53 (49.5%) contained this organism. the frequency of b. thuringiensis colonies was 4.4% among 4414 colonies of the bacillus cereus/b. thuringiensis group. the density of this bacterium in fresh waters averaged 0.45 cfu/ml. serologically, b. thuringiensis isolates were assigned to 26 h serotypes. of these, h14/36 (h s ... | 2000 | 10688688 |
| molecular cloning, nucleotide sequence and gene expression of a cytochrome p450 (cyp6f1) from the pyrethroid-resistant mosquito, culex quinquefasciatus say. | to analyze cytochrome p450s in the southern house mosquito, culex quinquefasciatus, we quantified the content of p450s and b5 in larval microsomes of guts and carcasses. results indicated that content was 30 times higher in guts than in carcasses. a conserved region in the alignment of insect p450 family 6 (cyp6) proteins served as a guide for the synthesis of degenerate oligonucleotide primers to clone p450 cdnas. primers were used in the reverse transcription-polymerase chain reaction (rt-pcr) ... | 2000 | 10696592 |
| cyt1a from bacillus thuringiensis synergizes activity of bacillus sphaericus against aedes aegypti (diptera: culicidae). | bacillus sphaericus is a mosquitocidal bacterium recently developed as a commercial larvicide that is used worldwide to control pestiferous and vector mosquitoes. whereas b. sphaericus is highly active against larvae of culex and anopheles mosquitoes, it is virtually nontoxic to aedes aegypti, an important vector species. in the present study, we evaluated the capacity of the cytolytic protein cyt1a from bacillus thuringiensis subsp. israelensis to enhance the toxicity of b. sphaericus toward a. ... | 2000 | 10698776 |
| botanical biocides. 4. mosquitocidal activity of certain thymus capitatus constituents. | successive extraction of thyme plant, thymus capitatus (l.) hoffm. and link (lamiaceae), by different solvents of increasing polarity, showed that potency was highly attributed to the non-polar fraction (e.g., petroleum ether) when tests were carried out against the larvae and adults of culex pipiens (l). of special concern to the mosquitocidal activity, the following fractions and isolates were recognized: the volatile oil, unsaponifiable portion, and certain compounds isolated from the unsapon ... | 2000 | 10701181 |
| genetics of mosquito vector competence. | mosquito-borne diseases are responsible for significant human morbidity and mortality throughout the world. efforts to control mosquito-borne diseases have been impeded, in part, by the development of drug-resistant parasites, insecticide-resistant mosquitoes, and environmental concerns over the application of insecticides. therefore, there is a need to develop novel disease control strategies that can complement or replace existing control methods. one such strategy is to generate pathogen-resi ... | 2000 | 10704476 |
| coexpression of cyt1aa of bacillus thuringiensis subsp. israelensis with bacillus sphaericus binary toxin gene in acrystalliferous strain of b. thuringiensis. | the cyt1aa gene of bacillus thuringiensis subsp. israelensis and binary toxin gene of bacillus sphaericus c3-41 were introduced into an acrystalliferous strain of b. thuringiensis independently and in combination by using shuttle vector pbu4. sds-page and western blot analysis proved that cyt1aa and binary toxin genes coexpressed during the sporulation of the recombinant. transformant strain expressing the cyt1aa and binary toxin proteins in combination was more toxic to susceptible and resistan ... | 2000 | 10706663 |
| [the circadian dynamics of the attacks of the synanthropic population of culex pipiens molestus mosquitoes at the staraia russa health resort]. | the diurnal biting activity of culex pipiens molestus in rooms of populated houses was studied in august 1998. the highest activity was recorded at 3.00-4.00 a. m., when 25-30 females attacked one volunteer rer 10 minutes. | 2000 | 10750157 |
| a new densovirus isolated from the mosquito culex pipiens (diptera: culicidae). | we have isolated from a laboratory strain of culex pipiens in which abnormal larval mortality occurred a small icosahedral nonenveloped dna virus sharing the main biological and biophysical properties of densoviruses (dnvs). unlike dnvs isolated previously from aedes species, i.e. the aaednv and the aaldnv (afanasiev, b.n., galyov, e. e., buchatsky, l.p., kozlov, y.v., 1991. nucleotide sequence and genomic organization of aedes densonucleosis virus. virology 185, 323-336; boublik, y., jousset, f ... | 2000 | 10773314 |
| larvicidal activity of commiphora molmol against culex pipiens and aedes caspius larvae. | myrrh (oleo-gum-resin) obtained from the stem of commiphora molmol proved to have insecticidal activity against mosquito larvae. the oil extract of myrrh possesses median lethal activity against 2nd, 3rd and 4th instar larvae of culex pipiens at 0.016 x 10(2), 0.17 x 10(2) & 1.6 x 10(2) g/l respectively. while lc50 against 3rd instar larvae of aedes caspius was 0.2 x 10(2) g/l. the oleo-resin extract showed toxicity against 2nd, 3rd, 4th instar larvae of c. pipiens recording the lc50 values of 0 ... | 2000 | 10786023 |
| [characterization of entomopathogenic bacillus samples isolated in senegal and study of their toxicity for malaria vectors]. | a screening program developed in senegal to isolate new strains of entomopathogenic bacillus has led to the isolation of 194 strains of bacillus thuringiensis and 9 strains of bacillus sphaericus from various sites and insect samples. the characterization of these strains regarding their h serotype, their crystal composition and their toxicity against mosquitoes (culex pipiens, aedes aegypti and anopheles stephensi) has led to the isolation of 27 mosquitocidal strains. as malaria is an important ... | 1998 | 10797955 |
| [an evaluation of male reproductive success by body size in swarms of culex pipiens pipiens (diptera: culicidae)]. | | 1999 | 10798956 |
| first field evidence for natural vertical transmission of west nile virus in culex univittatus complex mosquitoes from rift valley province, kenya. | west nile virus is a mosquito borne flavivirus endemic over a large geographic area including africa, asia, and the middle east. although the virus generally causes a mild, self-limiting febrile illness in humans, it has sporadically caused central nervous system infections during epidemics. an isolate of west nile virus was obtained from a pool of four male culex univittatus complex mosquitoes while we were conducting an investigation of rift valley fever along the kenya-uganda border in februa ... | 2000 | 10813479 |
| evaluation of immunoglobulin m (igm) and igg enzyme immunoassays in serologic diagnosis of west nile virus infection. | a unique urban encephalitis epidemic in romania signaled the emergence of neurological infection due to west nile (wn) virus as a novel public health threat in eastern europe and provided an opportunity to evaluate patterns of immunoglobulin g (igg) and igm reactivity in igm capture and igg enzyme-linked immunosorbent assays (elisas). wn virus infection was diagnosed serologically in 236 of 290 patients from whom acute serum or cerebrospinal fluid (csf) samples were available. in 37% of serum sa ... | 2000 | 10834982 |
| recent amplification of miniature inverted-repeat transposable elements in the vector mosquito culex pipiens: characterization of the mimo family. | we describe a new family of repetitive elements, named mimo, from the mosquito culex pipiens. structural characteristics of these elements fit well with those of miniature inverted-repeat transposable elements (mites), which are ubiquitous and highly abundant in plant genomes. the occurrence of mimo in c. pipiens provides new evidence that mites are not restricted to plant genomes, but may be widespread in arthropods as well. the copy number of mimo elements in c. pipiens ( approximately 1000 co ... | 2000 | 10854784 |
| cloning and characterization of a bacillus thuringiensis serovar higo gene encoding a novel class of the delta-endotoxin protein, cry27a, specifically active on the anopheles mosquito. | a novel gene encoding a 98-kda mosquitocidal delta-endotoxin protein, designated cry27a, was cloned from a bacillus thuringiensis serovar higo strain. the cry27a protein contained the five sequence blocks of amino acids commonly conserved in most b. thuringiensis cry proteins. relatively high homologies, ranging from 43.0% to 84.4%, existed between the cry27a protein and several established classes of mosquitocidal cry proteins (cry4a, cry10a, cry19a, cry19b, and cry20a) in the sequence of 51 n- ... | 2000 | 10879975 |
| parasporin, a human leukemic cell-recognizing parasporal protein of bacillus thuringiensis. | an unusual property, human leukemic cell-recognizing activity, associated with parasporal inclusions of a noninsecticidal bacillus thuringiensis soil isolate was investigated, and a protein (named parasporin in this study) responsible for the activity was cloned. the parasporin, encoded by a gene 2,169 bp long, was a polypeptide of 723 amino acid residues with a predicted molecular weight of 81, 045. the sequence of parasporin contained the five conserved blocks commonly found in b. thuringiensi ... | 2000 | 10882663 |
| isolation of borrelia afzelii from overwintering culex pipiens biotype molestus mosquitoes. | during the years 1995-1996, a total of 1,743 overwintering culex pipiens biotype molestus female mosquitoes were tested for the presence of spirochetes in several localities in south moravia, czech republic.the spirochetes were observed in 5% of the mosquitoes investigated. one of the five isolated strains of spirochetes (br-84) was identified as borrelia afzelii. the potential role of mosquitoes in the ecology and epidemiology of lyme disease (ld) borreliae should be further investigated. | 1999 | 10885843 |
| amplified esterases b1 and a2-b2 in field populations of culex pipiens from china. | the main organophosphate (op) resistance mechanism in the culex pipiens complex is increased activity of esterases a and b. fourth-stage larvae from 2 field populations of c. pipiens from gaomi and kunming, china, were compared for tolerance to parathion, dichlorovos (op), and bassa (carbamate) insecticides. both populations were resistant to ops but not to bassa. starch gel electrophoresis indicated that elevated esterase activity was correlated with op resistance. high frequencies of amplified ... | 2000 | 10901638 |
| laboratory evaluations of methylated soy oil and monoterpenes as mosquito larvicides. | the larvicidal toxicities of methylated soy oil (mso) and surfactant combinations were compared to 2 commercially available oil larvicides (golden bear oil 1111 and bonide) in standard laboratory bioassays of 4th-stage larvae of culex pipiens linn. the dose lethal to 50% of the test organisms (ld50) and the dose lethal to 95% of the test organisms (ld95) values are presented as microliters (microl) per beaker (treatment surface area of 54 cm2). the 2 surfactant-mso mixtures differed significantl ... | 2000 | 10901640 |
| recovery and identification of west nile virus from a hawk in winter. | west nile virus was recovered from the brain of a red-tailed hawk that died in westchester county, n.y., in february 2000. multiple foci of glial cells, lymphocytes, and a few pyknotic nuclei were observed in the brain. three to 4 days after inoculation of vero cells with brain homogenates, cytopathic changes were detected. the presence of west nile virus antigen in fixed cells or cell lysates was revealed by fluorescent antibody testing or enzyme-linked immunosorbent assay, respectively. furthe ... | 2000 | 10921991 |
| autogeny in culex pipiens quinquefasciatus say. | autogeny was observed in a laboratory colony of culex pipiens quinquefasciatus say originating from hyderabad, india. in a strain selected for an autogeny for 15 generations, all females, both mated and unmated, were able to mature eggs although the unmated females were unable to oviposit them. ingesting glucose had little effect on the expression of autogeny and on the number of eggs in rafts in the laboratory experiments. most autogenous females can ingest blood during first gonotrophic cycle, ... | 2000 | 10925805 |
| extended effect of bacillus thuringiensis h-14 on culex pipiens adults surviving larval treatment. | three bacillus thuringiensis h-14 preparations (a laboratory prepared and two commercial formulations namely, tecknar and vectobac) were assayed against third instar culex pipiens larvae in order to trace their toxic activity on larval treatment. the lc50 values were 0.002, 0.02 and 0.04 ppm. respectively. the laboratory strain was tested on the development of culex pipiens. larval mortality, pupation, adult emergence and sex ratio showed significant differences as compared to the non-treated gr ... | 2000 | 10946499 |
| assessment of two natural marine toxins (microcystis aeruginosa and parasicyonis actinostoloides) for the control of some medical and agriculture insects with reference to the action on mice. | the present work describes the insecticidal potentiality from microcystis aeruginosa (cyanobacteria) and parasicyonis actinostoloides (sea anemone) water extracts against 3rd larval instar of medical insects (musca domestica and culex pipiens) and 4th larval instar of agriculture insects (spodoptera littoralis and agrotis ipsilon. the ld50s of m. aeruginosa extract were 1.94, 2.33, 7.59 and 9.10 mg/ml. for m. domestica, c. pipiens, s. littoralis and a. ipsilon). respectively. while ld50s of p. a ... | 2000 | 10946523 |
| locomotory modes in the larva and pupa of chironomus plumosus (diptera, chironomidae). | the locomotory kinematics of chironomus plumosus larvae and pupae were investigated in order to determine how different locomotory techniques may be related to (a) possible underlying patterns of muscle activation and (b) the particular lifestyles and behaviours of these juvenile stages. larvae display three independent modes of motile activity: swimming, crawling and whole-body respiratory undulation. swimming and respiratory undulation involve the use of metachronal waves of body bending which ... | 2000 | 10980297 |
| the incrimination of aedes (stegomyia) aegypti as the vector of dirofilaria repens in nigeria. | six local species of culicides were identified as the common mosquitoes in zaria, out of 15 species captured using various adult and larval collection methods. these common culicides are culex pipiens fatigans, anopheles gambiae grp., mansonia africana, culex pipiens pipiens, aedes (stegomyia) aegypti and aedes vittatus. they were each fed directly on a local dog naturally infected with dirofilaria repens to evaluate their refractoriness/susceptibility to dirofilarial infection. in a number of d ... | 2000 | 10996744 |
| lipid utilization for ovarian development in an autogenous mosquito, culex pipiens molestus (diptera: culicidae). | during the first ovarian cycle, autogenous female mosquitoes develop their ovaries in the absence of blood feeding. in autogenous culex pipiens molestus (forskal), complete yolk deposition was observed 2 d after emergence, even when no feeding was allowed (starved). neutral lipids in cx. p. molestus increased during the pupal stage, abruptly declined after emergence, and again increased on day 3. in contrast, neutral lipids decreased in anautogenous anopheles stephensi (liston) and cx. p. pallen ... | 2000 | 11004785 |
| effects of density and larval competition on selected life history traits of culex pipiens quinquefasciatus (diptera: culicidae). | the effects of larval densities of one to four individuals in standard drosophila-vials (diameter 25 by 95 mm) on the age at pupation, starved dry weight, and wing length of culex pipiens quinquefasciatus say were studied. this approach required relatively few larvae per replicate and included a control treatment, where individual larvae developed in the absence of competition. this design also tested for competitive interactions between male and female larvae. mosquitoes pupated later, and emer ... | 2000 | 11004786 |
| vector competence of culex pipiens molestus (diptera: culicidae) from taiwan for a sympatric strain of japanese encephalitis virus. | laboratory strains of culex pipiens molestus forskal and culex tritaeniorhynchus giles from northern taiwan were compared for their susceptibility to the sanhsia mq1-2 (sh) strain of japanese encephalitis (je) virus isolated from taiwan. after feeding on a sweetened blood-virus mixture, viral titers in cx. p. molestus during the 14-d incubation period ranged from a minimum of 2.9 log10pfu (plaque forming units) per mosquito on day 3 after ingestion to a maximum of 4.65 log10pfu at day 8 and in c ... | 2000 | 11004796 |
| molecular strategies for interrupting arthropod-borne virus transmission by mosquitoes. | arthropod-borne virus (arbovirus) infections cause a number of emerging and resurgent human and veterinary infectious diseases. traditional means of controlling arbovirus diseases include vaccination of susceptible vertebrates and mosquito control, but in many cases these have been unavailable or ineffective, and so novel strategies for disease control are needed. one possibility is genetic manipulation of mosquito vectors to render them unable to transmit arboviruses. this review describes rece ... | 2000 | 11023962 |
| potential for new york mosquitoes to transmit west nile virus. | we evaluated the potential for several north american mosquito species to transmit the newly introduced west nile (wn) virus. mosquitoes collected in the new york city metropolitan area during the recent (1999) wn outbreak were allowed to feed on chickens infected with wn virus isolated from a crow that had died during this outbreak. these mosquitoes were tested approximately 2 weeks later to determine infection, dissemination, and transmission rates. culex pipiens mosquitoes were highly suscept ... | 2000 | 11037788 |
| ingested blood contributes to the specificity of the symbiosis of aeromonas veronii biovar sobria and hirudo medicinalis, the medicinal leech. | hirudo medicinalis, the medicinal leech, usually carries in its digestive tract a pure culture of aeromonas veronii bv. sobria. such specificity is unusual for digestive tracts that are normally colonized by a complex microbial consortium. important questions for the symbiotic interaction and for the medical application after microvascular surgery are whether other bacteria can proliferate or at least persist in the digestive tract of h. medicinalis and what factors contribute to the reported sp ... | 2000 | 11055917 |
| mosquito larvicidal activity of pipernonaline, a piperidine alkaloid derived from long pepper, piper longum. | a methanol extract of piper longum fruit was found to be active against mosquito larvae of culex pipiens pallens at 10 microg/ml after 24 h. a piperidine alkaloid, pipernonaline, was found to be responsible for this activity, with the 24-h median lethal dose (ld50) value for this compound being 0.21 mg/liter. the ld50 value of pipernonaline was not much higher than those for the 3 organophosphorous insecticides malathion, chlorpyrifos-methyl, and pirimiphos-methyl, used for comparative purpose i ... | 2000 | 11081654 |
| predation efficacy of the fish muddy loach, misgurnus mizolepis, against aedes and culex mosquitoes in laboratory and small rice plots. | assessments of the biological control potential of muddy loaches, misgurnus mizolepis, were conducted against aedes togoi, culex pipiens pallens, and culex inatomii larvae both in the laboratory and in small rice plots in pusan, korea, from june to september 1997. medium-sized fish consumed almost all of 500 3rd-stage larvae of cx. pipiens pallens offered daily in the laboratory. predation by the fish at release rates of 1, 2, 4, 8, and 16 fish per plot resulted in 1,004, 1,197, 1,198, 1,200, an ... | 2000 | 11081657 |
| [new species of microsporidia in the genus amblyospora from blood-sucking mosquitoes in the family culicidae]. | two microsporidians of the genus amblyospora from mosquito larvae of aedes and culex were studied in tomsk region (siberia). peculiarities of the sporogony and the meiospore ultrastructure were studied by light and electron microscopy. the meiospores of a. caspius sp. n. from aedes caspius and ae. communis measured on smears, were c. 4.8 x 3.6 microns in size. a polar filament was anisofilar with 5 wide (290 nm) and 9 narrow (190 nm) coils arranged in a single layer. a polaroplast of both specie ... | 2000 | 11089251 |
| plasmid transfer between bacillus thuringiensis subsp. israelensis strains in laboratory culture, river water, and dipteran larvae. | plasmid transfer between strains of bacillus thuringiensis subsp. israelensis was studied under a range of environmentally relevant laboratory conditions in vitro, in river water, and in mosquito larvae. mobilization of pbc16 was detected in vitro at a range of temperatures, ph values, and available water conditions, and the maximum transfer ratio was 10(-3) transconjugant per recipient under optimal conditions. transfer of conjugative plasmid pxo16::tn5401 was also detected under this range of ... | 2001 | 11133463 |
| birth of a retroposon: the twin sine family from the vector mosquito culex pipiens may have originated from a dimeric trna precursor. | sines are short interspersed repetitive elements found in many eukaryotic genomes and are believed to propagate by retroposition. almost all sines reported to date have a composite structure made of a 5' trna-related region followed by a trna-unrelated region. here, we describe a new type of trna-derived sines from the genome of the mosquito culex pipiens. these elements, called twins, are approximately 220 bp long and reiterated at approximately 500 copies per haploid genome. twins have a uniqu ... | 2001 | 11141194 |
| current status of malaria and potential for control. | malaria remains one of the world's worst health problems with 1.5 to 2.7 million deaths annually; these deaths are primarily among children under 5 years of age and pregnant women in sub-saharan africa. of significance, more people are dying from malaria today than 30 years ago. this review considers the factors which have contributed to this gloomy picture, including those which relate to the vector, the female anopheline mosquito; to human activity such as creating new mosquito breeding sites, ... | 2001 | 11148010 |
| genetic evidence for an interferon-antagonistic function of rift valley fever virus nonstructural protein nss. | rift valley fever virus (rvfv), a phlebovirus of the family bunyaviridae, is a major public health threat in egypt and sub-saharan africa. the viral and host cellular factors that contribute to rvfv virulence and pathogenicity are still poorly understood. all pathogenic rvfv strains direct the synthesis of a nonstructural phosphoprotein (nss) that is encoded by the smallest (s) segment of the tripartite genome and has an undefined accessory function. in this report, we show that mp12 and clone 1 ... | 2001 | 11152510 |
| eight novel families of miniature inverted repeat transposable elements in the african malaria mosquito, anopheles gambiae. | eight novel families of miniature inverted repeat transposable elements (mites) were discovered in the african malaria mosquito, anopheles gambiae, by using new software designed to rapidly identify mite-like sequences based on their structural characteristics. divergent subfamilies have been found in two families. past mobility was demonstrated by evidence of mite insertions that resulted in the duplication of specific ta, taa, or 8-bp targets. some of these mites share the same target duplicat ... | 2001 | 11172014 |
| european experience with the west nile virus ecology and epidemiology: could it be relevant for the new world? | a review of west nile virus (wnv) and the epidemiology of west nile fever (wnf) in europe is presented. european epidemics of wnf reveal some general features. they usually burst out with full strength in the first year, but few cases are observed in the consecutive 1 to 2 (exceptionally 3) years, whereas smaller epidemics or clusters of cases only last for one season. the outbreaks are associated with high populations of mosquitoes (especially culex spp.) caused by flooding and subsequent dry a ... | 2000 | 11192288 |
| west nile virus investigations in south moravia, czechland. | seven virus isolates were obtained from 11,334 mosquitoes after the 1997 morava river flooding in south moravia (czech republic): 6 strains of tahyna bunyavirus, california antigenic group (5 from aedes vexans, 1 from ae. cinereus), and 1 strain of west nile flavivirus (wnv) from culex pipiens. in 1999, one isolate of tahyna virus from ae. vexans and one isolate of wnv from cx. pipiens were recovered from a total of 14,354 mosquitoes examined in the same area, whereas no virus was detected there ... | 2000 | 11192289 |
| synthesis and stereostructure-activity relationship of three asymmetric center pyrethroids: 2-methyl-3-phenylcyclopropylmethyl 3-phenoxybenzyl ether and cyanohydrin ester. | 2-methyl-3-phenylcyclopropylmethyl 3-phenoxybenzyl ether 2 and cyanohydrin ester 3, a couple of pyrethroids with three asymmetric centers, were synthesized. of each of the four diastereomers of 2 and 3, only the (1r*,2r*,3r*)-2a and 3a showed significant insecticidal activities. dual sets of enantiomers [(1r,2r,3r)-(-)-2a and (1s,2s,3s)-(+)-2a] and [(1r,2r,3r)-(-)-3a and (1s,2s,3s)-(+)-3a] were synthesized through the asymmetric cyclopropanation using the aratani catalyst. significant separation ... | 2001 | 11197343 |
| potential for culex pipiens to develop resistance against bacillus sphaericus toxins. | susceptibility of field culex pipiens populations to bacillus sphaericus and the possibility of resistance development in the selected laboratory colony were investigated. 180 populations collected from giza and qualyobia over one year show no marked variation at lc50 and lc90 values. larvae of laboratory colony of cx pipiens were subjected to selection pressure with a preparation of bacillus sphaericus strain 2362 at lc80 values for 20 successive generations. the selected laboratory colony bega ... | 2000 | 11198382 |
| the effects of nosema algerae vavra and undeen (microsporida: nosematidae) pathogen of culex pipiens l.(diptera: culicidae) from egypt on fecundity and longevity of the host. | a microsporidian, nosema algerae vavra and undeen, was found parasitizing larvae and adults of a laboratory colony of culex pipiens l. originated from gharbia governorate. a detailed examination of the developmental stages of the pathogen under light and electron microscopes showed that they are typical of the original characteristics of n. algerae. other observations on the infected individuals revealed that spores of the pathogen were found in all organs of the infected mosquitoes except the n ... | 2000 | 11198385 |
| the abundance and seasonal distribution of culex mosquitoes in iowa during 1995-97. | the abundance and seasonal distribution of culex mosquitoes were monitored by measuring oviposition activity during the summers of 1995, 1996, and 1997. five species of culicine mosquitoes laid egg rafts in ovitraps. egg rafts of 4 culex species-cx. restuans (54.98%), cx. pipiens (25.41%), cx. salinarius (12.18%), and cx. tarsalis (0.14%)-constituted more than 92% of the total egg rafts collected. culiseta inornata (0.1%) was the only other species to lay viable egg rafts in the ovitraps. a smal ... | 2000 | 11198913 |
| differences in response to temperature and density between two strains of the mosquito, culex pipiens molestus forskal. | two strains of culex pipiens molestus of different geographical origin were reared for more than five years under the same laboratory conditions in order to study to what extent the reactions of these strains to constant temperature and density become similar. lower temperature and higher densities caused not only the prolongation of developmental time of preimaginal stages and increasing mortality of larvae and pupae in both strains but also the extension of the rate between the first and last ... | 2000 | 11217212 |
| species composition and seasonal dynamics of mosquitoes in the belek region of turkey. | the species composition and seasonal population dynamics of mosquitoes trapped in the belek region of turkey are described. eight traps (four new jersey light traps and four co2 baited traps) were activated weekly at four different sampling sites (wooded area, open field, village, and road edge). between may and december, 1997, 4,542 specimens representing seven species (culex pipiens, culex tritaeniorhynchus, aedes caspius, aedes cretinus, aedes dorsalis, aedes vexans, and culiseta annulata) we ... | 2000 | 11217213 |
| meconial peritrophic membranes and the fate of midgut bacteria during mosquito (diptera: culicidae) metamorphosis. | the location of midgut bacteria relative to meconial peritrophic membranes (mpms) and changes in bacterial numbers during midgut metamorphosis were studied in anopheles punctipennis (say), culex pipiens (l.), and aedes aegypti (l.) pupae and newly emerged adults. after adult emergence in aedes, anopheles, and most culex, there were few to no bacteria in the midgut. in most newly emerged adult mosquitoes, few bacteria were found in either the lumen or within the mpms/meconia. in a few culex speci ... | 2001 | 11268687 |
| detection of wuchereria bancrofti in mosquitoes by the polymerase chain reaction: a potentially useful tool for large-scale control programmes. | focally endemic bancroftian filariasis is targeted for elimination in the nile delta of egypt. improved methods are needed for identifying endemic villages to be included in the control programme and for monitoring its success. we have evaluated the performance of a polymerase chain reaction (pcr) assay in estimating wuchereria bancrofti infection in pools of culex pipiens (1-25 females) from 2 adjacent villages with high (el qolzom, 10.8%) and low (kafr shorafa, 2.1%) prevalence rates of human ... | 2001 | 11280059 |
| lack of cross-resistance to cry19a from bacillus thuringiensis subsp. jegathesan in culex quinquefasciatus (diptera: culicidae) resistant to cry toxins from bacillus thuringiensis subsp. israelensis. | culex quinquefasciatus mosquitoes with high levels of resistance to single or multiple toxins from bacillus thuringiensis subsp. israelensis were tested for cross-resistance to the bacillus thuringiensis subsp. jegathesan polypeptide cry19a. no cross-resistance was detected in mosquitoes that had been selected with the cry11a, cry4a and cry4b, or cry4a, cry4b, cry11a, and cyta toxins. a low but statistically significant level of cross-resistance, three to fourfold, was detected in the colony sel ... | 2001 | 11282656 |
| [canine dirofilariasis in the canton of ticino and in the neighboring areas of northern italy]. | the distribution of canine dirofilariosis in southern ticino (switzerland) and in the neighbouring provinces of varese and como (italy) was investigated. blood samples were collected from 308 dogs which had remained in the local area and were outdoor-housed, older than 1.5 years and had not been treated previously with preventive or microfilaricidal drugs. microfilariae of dirofilaria immitis and d. repens were found in 33 (10.7%) and 17 (5.5%) dogs, respectively. ten more dogs (3.2%) tested pos ... | 2001 | 11293933 |
| vector competence of north american mosquitoes (diptera: culicidae) for west nile virus. | we evaluated the potential for several north american mosquito species to transmit the newly introduced west nile (wn) virus. mosquitoes collected in the new york city metropolitan area during the recent wn virus outbreak, at the assateague island wildlife refuge, va, or from established colonies were allowed to feed on chickens infected with wn virus isolated from a crow that died during the 1999 outbreak. these mosquitoes were tested approximately 2 wk later to determine infection, disseminati ... | 2001 | 11296813 |
| identification and molecular structural prediction analysis of a toxicity determinant in the bacillus sphaericus crystal larvicidal toxin. | the operon containing the genes encoding the subunits of the binary crystal toxin of bacillus sphaericus strain lp1-g, bina and binb (41.9 kda and 51.4 kda, respectively), was cloned and sequenced. purified crystals were not toxic to culex pipiens larvae. comparison of the amino-acid sequences of this strain (bin4) with those of the three other known toxin types (bin1, bin2 and bin3) revealed mutations at six positions, including a serine at position 93 of bina4, whereas all other types of bina ... | 2001 | 11322897 |
| effect of incubation at overwintering temperatures on the replication of west nile virus in new york culex pipiens (diptera: culicidae). | we examined the effect of simulated overwintering temperatures on west nile (wn) virus replication in culex pipiens l. derived from mosquitoes collected during the autumn 1999 wn epizootic in new york. the wn virus was a strain isolated from a dead crow also collected during this outbreak. virus was recovered from most mosquitoes held exclusively at 26 degres c. in contrast, none of the mosquitoes held exclusively at the lower temperatures had detectable infections. when mosquitoes were transfer ... | 2001 | 11372976 |
| highly toxic and broad-spectrum insecticidal bacillus thuringiensis engineered by using the transposon tn917 and protoplast fusion. | the chromosome of the bacillus thuringiensis strain s184 that was toxic against the third instar larvae of spodoptera litura with the lc(50) of 9.74 microg/ml was successfully integrated into two genes of cyt1aa and cry11aa using the transposon tn917, yielding the primary engineered strain tnx. the strain tnx was highly toxic to the third instar larvae of culex pipiens fatigans with the lc(50) of 5.12 ng/ml which was 1.82-fold higher than that of b. thuringiensis subsp. israelensis, but lowly to ... | 2001 | 11391474 |
| cyt1ab1 and cyt2ba1 from bacillus thuringiensis subsp. medellin and b. thuringiensis subsp. israelensis synergize bacillus sphaericus against aedes aegypti and resistant culex quinquefasciatus (diptera: culicidae). | the interaction of two cytolytic toxins, cyt1ab from bacillus thuringiensis subsp. medellin and cyt2ba from bacillus thuringiensis subsp. israelensis, with bacillus sphaericus was evaluated against susceptible and resistant culex quinquefasciatus and the nonsensitive species aedes aegypti. mixtures of b. sphaericus with either cytolytic toxin were synergistic, and b. sphaericus resistance in c. quinquefasciatus was suppressed from >17,000- to 2-fold with a 3:1 mixture of b. sphaericus and cyt1ab ... | 2001 | 11425753 |
| comparative linkage map development and identification of an autosomal locus for insensitive acetylcholinesterase-mediated insecticide resistance in culex tritaeniorhynchus. | a comparative linkage map for culex tritaeniorhynchus was constructed based on restriction fragment length polymorphism markers using cdnas from aedes aegypti. linear orders of marker loci in cx. tritaeniorhynchus were identical to culex pipiens wherein chromosomes 2 and 3 reflect whole-arm rearrangements compared to a. aegypti. however, the sex determination locus in cx. tritaeniorhynchus maps to chromosome 3, in contrast to cx. pipiens and ae. aegypti where it is located on chromosome 1. our r ... | 2001 | 11437911 |
| the vortex wake of the free-swimming larva and pupa of culex pipiens (diptera). | the kinematics and hydrodynamics of free-swimming pupal and larval (final-instar) culicids were investigated using videography and a simple wake-visualisation technique (dyes). in both cases, swimming is based on a technique of high-amplitude, side-to-side (larva) or up-and-down (pupa) bending of the body. the pupa possesses a pair of plate-like abdominal paddles; the larval abdominal paddle consists of a fan of closely spaced bristles which, at the reynolds numbers involved, behaves like a cont ... | 2001 | 11441028 |
| western nile virus: a new public health concern. | in august 1999, the western hemisphere was introduced to the western nile virus for the first time in recorded history. many states have implemented screening and identification protocols for this previously rare virus. western nile virus (wnv) is a member of the flaviviridae family and it is transmitted by the culex pipiens mosquito, although other mosquito species have also been implicated in carrying the virus. human infection with west nile virus can range from asymptomatic to full blown enc ... | 2001 | 11471465 |
| induction of oogenesis in mosquitoes (diptera: culicidae) by infusion of the hemocoel with amino acids. | as done previously with adult females of culex pipiens pallens coquillett, a mixture of 17 amino acids was infused into the hemocoel of females of seven anautogenous and one autogenous mosquito species belonging to three genera. in culex. p. quinquefasciatus say, cx. tritaeniorhynchus giles, cx. kyotoensis yamaguti & lacasse, aedes albopictus (skuse), armigeres subalbatus (coquillett), and cx. p. molestus forskal, which previously had laid autogenously matured first batch of eggs, ovarian develo ... | 2001 | 11476338 |
| biochemical changes of culex pipiens larvae treated with oil and oleo-resin extracts of myrrh commiphora molmol. | the mosquitocidal plant extracts of the myrrh, commiphora molmol namely; oil and oleo-resin, were proved to demonstrate larvicidal activity against culex pipiens larvae. oleo-resin was found to induce significant higher toxic action than oil. solvent (cremophore el) did not perform any toxic activity. the impact of both oleo-resin and oil extracts on the protein profile of the treated larvae was evaluated in order to explain their mode of action. electrophoretic analysis of total proteins, lipop ... | 2001 | 11478451 |
| ochlerotatus j. japonicus in frederick county, maryland: discovery, distribution, and vector competence for west nile virus. | ochlerotatus japonicus japonicus is reported for the 1st time south of the mason-dixon line, in frederick county, maryland. fifty-seven oviposition trap samples were collected throughout the county between june 30 and august 24, 2000. from 971 larvae reared from the oviposition traps, 5 species were identified: ochlerotatus triseriatus (45%), oc. j. japonicus (43%), aedes albopictus (7%), culex pipiens (4%), and toxorynchites ritulus septentrionalis (<1%). ochlerotatus j. japonicus was found wid ... | 2001 | 11480822 |
| the receptor of bacillus sphaericus binary toxin in culex pipiens (diptera: culicidae) midgut: molecular cloning and expression. | culex pipiens larval midgut is the primary target of the binary toxin (bin) present in parasporal inclusions of bacillus sphaericus. cpm1, a 60-kda protein purified from brush border membranes, has been proposed as the receptor of the bin toxin in the midgut epithelial cells of mosquitoes. we have cloned and characterized the corresponding cdna from midgut of culex pipiens larvae. the open reading frame predicted a 580 amino-acid protein with a putative signal peptide at the n-terminus and a put ... | 2001 | 11483434 |
| thyroid-stimulating hormone and growth hormone release alterations induced by mosquito larvae proteins on pituitary cells. | mosquito larvae crude extract has shown to modulate cell proliferation of different mouse epithelial as well as human mononuclear cell populations in vivo and in vitro. a soluble fraction of the extract, with a molecular weight ranging from 12 to 80 kd, also showed an inhibitory effect on the proliferation of mouse hepatocytes. this effect disappeared after heating the extract at 90 degrees c for 60 min, suggesting that some proteinaceous molecule is involved. we report the effect of dialysed ex ... | 2001 | 11518495 |
| preoviposition activation of cathepsin-like proteinases in degenerating ovarian follicles of the mosquito culex pipiens pallens. | within developing ovaries of many insects, some developing follicles or oocytes usually degenerate (follicular atresia or oosorption), while the others may continue to grow to maturity, thus maintaining the balance between the number of eggs and reproductive circumstances such as available nutrients. to help clarify the phenomenon of follicular atresia during ovarian development, we examined cysteine proteinases stored in mosquito culex pipiens pallens ovaries. first, analysis using synthesized ... | 2001 | 11518506 |
| effects of microcosm scaling and food resources on growth and survival of larval culex pipiens. | we used a simple experimental design to test for the effects of microcosm scaling on the growth and survival of the mosquito, culex pipiens. microcosm and mesocosm studies are commonly used in ecology, and there is often an assumption that scaling doesn't affect experimental outcomes. the assumption is implicit in the design; choice of mesocosms may be arbitrary or based on convenience or cost. we tested the hypothesis that scale would influence larvae due to depth and surface area effects. larv ... | 2001 | 11527507 |
| recombination between two amplified esterase alleles in culex pipiens. | esterase gene amplification at the ester superlocus provides organophosphate resistance in the mosquito culex pipiens (l.). in this study we explored the possibility of recombination between two amplified esterase alleles, thus generating a composite amplified allele. to do that, females heterozygous for two distinct amplified alleles (ester(2) and ester(4)) were crossed with males homozygous for a third resistance allele (ester(8)). among analyzed offspring, one recombinant composite allele (es ... | 2001 | 11535649 |
| baseline susceptibility to bacterial insecticides in populations of culex pipiens complex (diptera: culicidae) from california and from the mediterranean island of cyprus. | bacterial insecticides play an increasingly important role in mosquito control. to establish guidelines for detecting resistance at an early stage, information on natural variation in susceptibility of insect populations to these insecticides is needed. between 1990 and 1993, the susceptibility of culex pipiens l. complex to bacillus thuringiensis subsp. israelensis de barjac and/or bacillus sphaericus neide was determined in 31 collections from california. these collections were undertaken befo ... | 2001 | 11561853 |
| isolation of bacillus thuringiensis from intertidal brackish sediments in mangroves. | intertidal brackish sediments in mangroves were examined for isolation of bacillus thuringiensis strains with novel toxicity spectra. a total of 18 b. thuringiensis isolates were recovered from eight sediment samples (36.4%) out of 22 samples tested. the frequency of b. thuringiensis was 1.3% among the colonies of bacillus cereus/b. thuringiensis group. while five isolates were allocated to the four h serogroups, the majority of the isolates were serologically untypable or untestable. two isolat ... | 2001 | 11572461 |
| resistance to bacillus sphaericus in culex pipiens (diptera: culicidae): interaction between recessive mutants and evolution in southern france. | in southern france, failure to control culex pipiens l. with bacillus sphaericus neide toxin (bs) was first detected in 1994, at the extreme east of the languedoc-roussillon coast. this failure was due to a single recessive mutant, sp-1r. two complementary strategies were used to test whether sp-1r had invaded the bs-controlled area by 1998. first, a strain (bp) was selected from resistant larvae sampled in the western part of the bs-controlled area. in bp strain, resistance involved a single re ... | 2001 | 11580038 |
| overproduced esterases in culex pipiens quinquefasciatus (diptera: culicidae) from vietnam. | the electrophoretic polymorphism of loci encoding for 10 enzymes was studied in culex p. quinquefasciatus say from six localities of vietnam. the analysis of 11 "neutral genes" showed that differentiation among samples was low, but significant (fst = 0.06), and significantly related to geographic distance between sample sites. these results are similar to those observed in other countries (europe and west africa). a single type of overproduced esterases (a2-b2) was observed, and its frequency wa ... | 2001 | 11580049 |
| west nile virus isolates from mosquitoes in new york and new jersey, 1999. | an outbreak of encephalitis due to west nile (wn) virus occurred in new york city and the surrounding areas during 1999. mosquitoes were collected as part of a comprehensive surveillance program implemented to monitor the outbreak. more than 32,000 mosquitoes representing 24 species were tested, and 15 wn virus isolates were obtained. molecular techniques were used to identify the species represented in the wn virus-positive mosquito pools. most isolates were from pools containing culex pipiens ... | 2001 | 11585523 |
| mosquito surveillance for west nile virus in connecticut, 2000: isolation from culex pipiens, cx. restuans, cx. salinarius, and culiseta melanura. | fourteen isolations of west nile (wn) virus were obtained from four mosquito species (culex pipiens [5], cx. restuans [4], cx. salinarius [2], and culiseta melanura [3]) in statewide surveillance conducted from june through october 2000. most isolates were obtained from mosquitoes collected in densely populated residential locales in fairfield and new haven counties, where the highest rates of dead crow sightings were reported and where wn virus was detected in 1999. minimum field infection rate ... | 2001 | 11585530 |
| west nile virus infection in birds and mosquitoes, new york state, 2000. | west nile (wn) virus was found throughout new york state in 2000, with the epicenter in new york city and surrounding counties. we tested 3,403 dead birds and 9,954 mosquito pools for wn virus during the transmission season. sixty-three avian species, representing 30 families and 14 orders, tested positive for wn virus. the highest proportion of dead birds that tested positive for wn virus was in american crows in the epicenter (67% positive, n=907). eight mosquito species, representing four gen ... | 2001 | 11585532 |
| ross river virus transmission, infection, and disease: a cross-disciplinary review. | ross river virus (rrv) is a fascinating, important arbovirus that is endemic and enzootic in australia and papua new guinea and was epidemic in the south pacific in 1979 and 1980. infection with rrv may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. rrv disease notifications in australia average 5,000 per year. the first well-described outbreak occurred in 1928. during world war ii there were more outbreaks, and the name ep ... | 2001 | 11585790 |
| west nile virus infection in mosquitoes, birds, horses, and humans, staten island, new york, 2000. | west nile (wn) virus transmission in the united states during 2000 was most intense on staten island, new york, where 10 neurologic illnesses among humans and 2 among horses occurred. wn virus was isolated from aedes vexans, culex pipiens, cx. salinarius, ochlerotatus triseriatus, and psorophora ferox, and wn viral rna was detected in anopheles punctipennis. an elevated weekly minimum infection rate (mir) for cx. pipiens and increased dead bird density were present for 2 weeks before the first h ... | 2001 | 11589172 |
| a phylogenetic approach to following west nile virus in connecticut. | the 1999 outbreak of west nile (wn) virus in the northeastern united states was the first known natural occurrence of this flavivirus in the western hemisphere. in 1999 and 2000, 82 independent connecticut wn virus isolates were cultured from nine species of birds, five species of mosquitoes, and one striped skunk. nucleotide sequences obtained from these isolates identified 30 genetic changes, compared with wn-ny99, in a 921-nt region of the viral genome beginning at nucleotide position 205 and ... | 2001 | 11606791 |
| aromatic plants in bird nests as a protection against blood-sucking flying insects? | the nest protection hypothesis suggests that some of the fresh plant material, brought by some bird species to their nests, contain secondary compounds that repel parasites or mask the chemical cues that parasites use to find the host. corsican blue tits (parus caeruleus) bring pieces of several species of aromatic plants to the nest at dusk, suggesting a protection against nocturnal agents such as blood-sucking flying insects. the potential repellent or masking effect of these aromatic plant sp ... | 2001 | 11672937 |
| immunization of mice against west nile virus with recombinant envelope protein. | west nile (wn) virus is a mosquito-borne flavivirus that emerged in the united states in 1999 and can cause fatal encephalitis. envelope (e) protein cdna from a wn virus isolate recovered from culex pipiens in connecticut was expressed in escherichia coli. the recombinant e protein was purified and used as ag in immunoblot assays and immunization experiments. patients with wn virus infection had abs that recognized the recombinant e protein. c3h/hen mice immunized with e protein developed e prot ... | 2001 | 11673542 |
| various levels of cross-resistance to bacillus sphaericus strains in culex pipiens (diptera: culicidae) colonies resistant to b. sphaericus strain 2362. | we studied the cross-resistance to three highly toxic bacillus sphaericus strains, iab-59 (serotype h6), iab-881 (serotype h3), and iab-872 (serotype h48), of four colonies of the culex pipiens complex resistant to b. sphaericus 2362 and 1593, both of which are serotype h5a5b strains. two field-selected highly resistant colonies originating from india (kochi, 17,000-fold resistance) and france (sphae, 23,000-fold resistance) and a highly resistant laboratory-selected colony from california (geor ... | 2001 | 11679325 |
| isolation and characterization of a bacillus thuringiensis ssp. kurstaki strain toxic to spodoptera exigua and culex pipiens. | a strain of bacillus thuringiensis with dual toxicity was isolated from korean soil samples and named k2. k2 was determined as ssp. kurstaki (h3a3b3c) by serological test and produced bipyramidal-shaped parasporal inclusions. the plasmid and protein profiles of b. thuringiensis k2 were different from those of the reference strain, ssp. kurstaki hd-1. to verify gene type of b. thuringiensis k2, pcr analysis with specific cry gene primers was performed. the result showed that b. thuringiensis k2 h ... | 2001 | 11683364 |
| invasions by insect vectors of human disease. | nonindigenous vectors that arrive, establish, and spread in new areas have fomented throughout recorded history epidemics of human diseases such as malaria, yellow fever, typhus, and plague. although some vagile vectors, such as adults of black flies, biting midges, and tsetse flies, have dispersed into new habitats by flight or wind, human-aided transport is responsible for the arrival and spread of most invasive vectors, such as anthropophilic fleas, lice, kissing bugs, and mosquitoes. from th ... | 2002 | 11729075 |