dengue vector control: present status and future prospects.dengue fever (df) and dengue haemorrhagic fever (dhf) have been the most common urban diseases in southeast asia since the 1950s. more recently, the diseases have spread to central and south america and are now considered as worldwide diseases. both aedes aegypti and aedes albopictus are involved in the transmission of df/dhf in southeast asian region. the paper discusses the present status and future prospects of aedes control with reference to the malaysian experience. vector control approache ...19947844836
dengue in the health transition.the "health transition" describes the medical consequences which accompany the demographic transition and development. in many asian countries, as the infectious diseases of infancy decline, such as diarrhea, acute respiratory disease, measles and malaria, so too, do infant mortality rates. as a consequence of falling infant mortality rates and declines in fertility, the age pyramid has become more rectangular. no longer is nearly half of the population under the age of 15 years. diseases of adu ...19947844846
dengue vector control in the urban environment of epidemic of dengue occurred in southern taiwan in 1987, and by the end of 1988 there were 10,420 reported cases, of which 60.5% were from kaohsiung municipality. the urbanization and industrialization of the municipality have resulted in a vast increase in the breeding habitats of the dengue vector, aedes aegypti. in the early stage of the epidemic, only space spraying with insecticides was undertaken, but the aedes density gradually increased and reached its peak in the third quarter of 1988 ...19947844847
control of dengue vectors in singapore.singapore has a well-established system for the surveillance, research and control of aedes aegypti and aedes albopictus. control of these vectors comes under the jurisdiction of the environmental public health division of the ministry of the environment. the strategy for aedes control is an integrated approach incorporating case detection, source reduction, health education and law enforcement. this is done through the quarantine & epidemiology department (dengue surveillance and research), vec ...19947844848
intersectoral approaches to dengue vector control.medical entomology in the context of urban vector control, especially for dengue, can be likened to the tail of a dog. vertically structured aedes aegypti campaigns such as run by gorgas and soper earlier this century relied on sufficient legislative backing for vector control to ensure that the tail was capable of wagging the dog. under these conditions, especially where individual rights do not intrude, vertical programs will be successful. the global expansion of dengue, dengue hemorrhagic fe ...19947844851
ecology and control of dengue vector mosquitoes in taiwan.due to rapid urbanization, industrialization and social changes in recent years, the use of packing materials and tires has dramatically increased in the taiwan area. what is more is that some parts of southern taiwan are short of water resources and water preservation with huge containers becomes part of custom in those areas. storage water containers, waste vessels and tires are good habitats for aedes. meanwhile, some persons traveling to dengue endemic countries bring the dengue disease back ...19947844855
surveillance and control of aedes aegypti in epidemic areas of taiwan.aedes aegypti is the main, if not the only, vector of dengue fever in taiwan. the dengue epidemics that have occurred in taiwan correlate with the distribution of aedes aegypti which is limited to south of the tropic of cancer. during the 1987 outbreak of dengue fever in taiwan, the average larval density for the months july-december in the five cities and counties of southern taiwan was 2,284 larvae per 100 households. after control measures were taken, the average annual larval density in the ...19947844856
concomitant malaria (plasmodium gallinaceum) and filaria (brugia pahangi) infections in aedes aegypti: effect on parasite development.mixed infections with malarial (plasmodium gallinaceum) and filarial (brugia pahangi) parasites were carried out in 8 trials with filaria susceptible (refm) and filaria refractory (rep-rr) aedes aegypti strains. a secondary infection with b. pahangi microfilariae (mff) by intrathoracic inoculation, reduced the development rate of a pre-existing p. gallinaceum infection. the level of reduction ranged from 9.5 to 49% in refm and from 50 to 90% in rep-rr. an immune response against oocysts was seen ...19957845706
synergism of mosquitocidal toxicity between cyta and cryivd proteins using inclusions produced from cloned genes of bacillus thuringiensis.the toxicity to mosquito larvae of the parasporal body produced by bacillus thuringiensis subsp. israelensis and the pg-14 isolate of b. thuringiensis subsp. morrisoni is at least 20-fold greater than any of the four mosquitocidal proteins of which it is composed (cyta, cryiva, b, and d). this high toxicity is postulated to be due to synergistic interactions among parasporal proteins. however, this remains controversial because values reported for the specific toxicity of individual proteins, es ...19947854129
estimates of population size, dispersal, and longevity of domestic aedes aegypti aegypti (diptera: culicidae) by mark-release-recapture in the village of shauri moyo in eastern kenya.estimates of the absolute size of a domestic population of aedes aegypti aegypti (l.) were made in the rabai area of kenya, based on a single release, followed by either single or repeated recaptures. from single recapture within 24 h of release, the size of the female ae. a. aegypti population in the shauri moyo village was estimated by the lincoln index to be 365. using a single release and repeated recaptures, population size was estimated by jackson's positive method to be 337. depletion of ...19957869339
growth-restricted dengue virus mutants containing deletions in the 5' noncoding region of the rna genome.the dengue type 4 virus (den4) rna genome contains a 101-nt 5' noncoding (nc) sequence which is predicted to form a stable secondary structure. den4 cdna from which infectious rna can be transcribed was used to engineer deletions in the 5' nc region for functional analysis of rna structure and for isolation of den4 mutants that could be evaluated as candidates for use in a live attenuated vaccine. eleven distinct deletions in the region of the den4 genome between nts 18 and 98 were constructed; ...19957871753
short report: dispersal of aedes aegypti in an urban area after blood feeding as demonstrated by rubidium-marked eggs.strategies for the control of aedes aegypti during urban outbreaks of dengue or yellow fever assume that this species has a maximum flight range of 50-100 meters. because ae. aegypti distributes its eggs among several oviposition sites, we postulated that dispersal is driven by the search for oviposition sites, so an ovipositing female may have to fly much further than 50-100 meters to lay all of her eggs. we developed a method for marking ae. aegypti eggs with a rare alkali metal (rubidium) and ...19957872449
inhibition of mouse parenchymal cells proliferation by mosquito larvae it is known, some cell populations of mosquito aedes aegypti larvae do not proliferate. this fact suggests the existence of some mitosis inhibiting factor. we have assayed the effect of mosquito larvae crude extract on 85 c3hs young male mice (25 +/- 1 days old) and the effect of the dialyzed fraction of the same extract on 47 partially hepatectomized c3hs adult male mice. the injection was performed at 16:00 hour (before the raising of the dnas curve) and the controls were made at 08:00/16, ...19947873990
5-hydroxytryptamine in the salivary glands of adult female aedes aegypti and its role in regulation of salivation.a dense plexus of axons, immunoreactive to antisera against 5-hydroxytryptamine (5-ht, serotonin) and surrounding the proximal medial lobe of the salivary gland of adult female aedes aegypti mosquitoes, was demonstrated by means of whole-mount fluorescence immunocytochemistry. this innervation originates in the stomatogastric nervous system. 5-ht-immunoreactive innervation is absent in male salivary glands, suggesting that 5-ht is involved in blood-feeding. furthermore, female mosquitoes treated ...19957891033
mosquito host range and specificity of edhazardia aedis (microspora: culicosporidae).edhazardia aedis was transmitted horizontally to its natural host, aedes aegypti, and to 6 alternate hosts: ae. albopictus, ae. triseriatus, ae. taeniorhynchus, anopheles quadrimaculatus, orthopodomyia signifera and toxorhynchites rutilus rutilus. the microsporidium produced both binucleate and uninucleate spores in all susceptible hosts. transovarial transmission, however, was only successful in ae. aegypti. therefore, while e. aedis can infect a variety of mosquito species from diverse genera, ...19937902414
experimental infection of aedes aegypti mosquitoes, suckling mice, and rats with four mosquito spiroplasmas.four mosquito spiroplasmas, spiroplasma culicicola, spiroplasma sabaudiense, spiroplasma taiwanense, and an isolate designated cuas-1 were nonpathogenic for suckling mice and suckling rats inoculated either intracerebrally or intraperitoneally. s. culicicola persisted as long as 14 days in the brain of intracerebrally inoculated mice but did not replicate. the three other spiroplasmas were not reisolated from inoculated rats or mice. s. culicicola replicated in vitro at 37 degrees c in m1d media ...19947906284
the suitability of restriction fragment length polymorphism markers for evaluating genetic diversity among and synteny between mosquito species.restriction fragment length polymorphism (rflp) markers derived from the yellow fever mosquito, aedes aegypti, were used in hybridizations to genomic dna of the following mosquito species: ae. albopictus, ae. togoi, armigeres subalbatus, culex pipiens, and anopheles gambiae. interspecific hybridization with ae. aegypti probes varied from 50% (an. gambiae) to 100% (ae. albopictus) under high stringency conditions. we demonstrated the usefulness of using rflp profiles to examine genetic diversity ...19947909414
adult cat flea (siphonaptera: pulicidae) excretion of host blood proteins in relation to larval nutrition.protein content and ion composition of host blood and feces from blood-fed adult cat fleas, ctenocephalides felis (bouché), were examined. total fecal protein differed slightly from host blood indicating that there was little digestion of host blood by adult fleas. sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of host blood and flea feces also revealed little digestion, as evidenced by the quantitatively and qualitatively similar protein banding patterns. blood and fecal ion com ...19947910638
efficacy of clostridium bifermentans serovar malaysia on target and nontarget organisms.clostridium bifermentans serovar malaysia (c.b.m.) is highly toxic to mosquito larvae. in this study, the following aquatic nontarget invertebrates were treated with high c.b.m. concentrations (up to 1,600-fold the toxic concentration for anopheles stephensi) to study their susceptibility towards the bacterial toxin: planorbis planorbis (pulmonata); asellus aquaticus (isopoda); daphnia pulex (cladocera); cloeon dipterum (ephemeroptera); plea leachi (heteroptera); and eristalis sp., chaoborus cry ...19947912261
host range tests with edhazardia aedis (microsporida: culicosporidae) against northern nearctic mosquitoes.twelve species of northern nearctic mosquitoes representing five genera (aedes, anopheles, culex, culiseta, and psorphora) were bioassayed for susceptibility to edhazardia aedis, an exotic, heterosporous, microsporidian parasite of the yellow fever mosquito, aedes aegypti. infections were achieved in aedes atropalpus, aedes triseriatus, and aedes vexans following oral ingestion of uninucleate spores obtained from patently infected ae. aegypti larvae. the microsporidium underwent normal vegetativ ...19947914904
biochemical basis of ddt-resistance in aedes aegypti population from a dengue affected area in shahjahanpur city.entomological studies conducted in jalalnagar, shahjahanpur city, uttar pradesh, india, during an outbreak of dengue in 1992, showed that ae. aegypti mosquitoes were resistant to ddt and had some tolerance to malathion in the adults and the larvae. biochemical analysis suggested that ddt resistance was related to elevated glutathione s-transferase and tolerance to malathion was due to a little increase in esterase activity. crosses of ddt-resistant and susceptible strain suggested that resistanc ...19947927578
reinterpretation of the genetics of susceptibility of aedes aegypti to plasmodium gallinaceum.several studies have demonstrated a genetic basis for variation in susceptibility of aedes aegypti to plasmodium gallinaceum. although 25 yr ago it was reported that p. gallinaceum susceptibility in ae. aegypti is determined primarily by a single autosomal dominant gene, evidence for additional genetic factors has emerged. two sublines, 1 refractory and 1 of intermediate susceptibility to p. gallinaceum, have been selected from the moyo-in-dry strain (moyo) of ae. aegypti. prior to selection, th ...19947931905
reproductive fitness and survivorship of aedes aegypti (diptera: culicidae) maintained on blood, with field observations from thailand.daily survivorship and fecundity of aedes aegypti mosquitoes were monitored for cohorts provided with five nutritional treatments: water, 2% sucrose, blood from a live chicken plus water, blood plus 2% sucrose, and blood alone. the median mortality time (lt50) for these females was 6, 54, 16, 12, and 29 d, respectively. there was no significant difference in the number of eggs laid by females in any of the treatments containing a host. females maintained on blood alone laid as many or more eggs ...19947932609
mosquito gonotrophic cycle and multiple feeding potential: contrasts between anopheles and aedes (diptera: culicidae).two aedine and three anopheline species were allowed to blood-feed to repletion, and their host-seeking behavior was measured with an olfactometer at intervals afterward. both aedes aegypti (l.) and ae. albopictus (skuse) were inhibited from subsequently seeking a host during the gonotrophic cycle, but anopheles gambiae giles, an. albimanus wiedemann, and an. freeborni aitken, all showed varying degrees of host-seeking behavior while their eggs matured. continued host-seeking by some anophelines ...19947932610
inheritance of oral susceptibility of aedes aegypti to chikungunya virus.a colony of rosy eye mutants of aedes aegypti was established. this strain was refractory to chikungunya virus by oral route of infection when compared with the wild-type parent strain. the refractoriness of this strain seems to be due to a mesentronal barrier, since both the mosquito strains supported the multiplication of virus after intrathoracic inoculation. the rosy eye strain was also found to be refractory to sagiyama virus (alphaviridae: getah virus subtype) when compared with wild-type ...19947943547
microscopic visualization of wuchereria and brugia larval stages in intact cleared mosquitoes.over the past several decades, epidemiologic data from filarial vectors typically has been obtained by mass dissection or by dissection of individual specimens. the former is quick and easy to do on large numbers of insects but provides no information on the frequency distribution of infection, presence of early developmental stages, or larval location; the latter is labor-intensive and tedious. we describe a new technique that can provide data comparable to those obtained by individual dissecti ...19947943576
aedes aegypti: characterization of a hemolymph polypeptide expressed during melanotic encapsulation of filarial worms.we report on the initial characterization of an 84-kda polypeptide that is differentially expressed in aedes aegypti during melanotic encapsulation immune reactions against filarial worms. [35s]methionine-labeled hemolymph from mosquitoes inoculated with saline, parasites that are melanized, or parasites that are not melanized was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. results show that the level of the 84-kda polypeptide increases considerably in those mosquitoes ...19947957753
densovirus of aedes aegypti as an expression vector in mosquito cells.we have constructed an infectious dna clone containing the genome of aedes aegypti densovirus (aednv) in a bacterial plasmid. when this clone was transfected into aedes albopictus c6/36 mosquito cells, the aednv genome rescued from the plasmid and replicated as the wild-type virus. to investigate the cloned virus as an expression vector, the reporter gene encoding beta-galactosidase (beta-gal) was inserted into four large open reading frames (orf) observed in the aednv genome. when these recombi ...19947957754
insecticide susceptibility in mosquitoes (diptera: culicidae) from french polynesia.susceptibility to six organophosphate (op), two pyrethroid (py), and one carbamate (c) insecticides was investigated in culex pipiens quinquefasciatus say, aedes aegypti (l.), and aedes polynesiensis marks larvae from the island of tahiti. cx. p. quinquefasciatus and ae. aegypti were compared with susceptible reference strains treated simultaneously. a low, but significant, resistance to bromophos (4.6x), chlorpyrifos (5.7x), fenthion (2.4x), fenitrothion (5.0x), temephos (4.3x) and permethrin ( ...19947966164
salivary vasodilators of aedes triseriatus and anopheles gambiae (diptera: culicidae).salivary vasodilators of aedes aegypti (l.) and anopheles albimanus (wiedemann) were characterized previously as a tachykinin peptide and a catechol oxidase/peroxidase activity, respectively. to verify whether these two different vasodilators also were found in other distantly related members of each mosquito genus, we characterized the vasodilators from a. triseriatus and a. gambiae. a. triseriatus salivary gland homogenates produced a reversible, endothelium dependent vasorelaxation of rabbit ...19947966179
[seasonal variations in aedes aegypti populations in monterrey, mexico].seasonal variation of the populations of the dengue vector mosquito aedes aegypti, in the city of monterrey, n.l., mexico, showed a bimodal pattern. the first peak is lower and appeared at early june, while the second and higher one was observed in the second week of october. 1,419 female mosquitoes were caught in this study. females with fresh red blood in the stomach were present in all the catches, gravid females (mature eggs in the ovaries) being more abundant than the non-gravid ones. the g ...19947973991
elisa for detecting dengue and japanese encephalitis viral antigen in indirect elisa has been developed for detecting two viruses in triturated, experimentally infected mosquitoes: dengue (den) in aedes aegypti (l.) and ae. albopictus (skuse) and japanese encephalitis (je) viral antigen in culex tritaeniorhynchus giles. den antigen from four strains of the virus, representing each of the four serotypes, and je antigen were captured with a polyclonal anti-flavivirus igg and detected with a monoclonal antibody (4g2) that reacts with all flaviviruses. minimum vira ...19947979627
differential modulation of murine cellular immune responses by salivary gland extract of aedes aegypti.the ability of salivary gland extract (sge) of aedes aegypti to modulate cellular immune responses was investigated in a mouse model. cytokine production was induced in naive and antigen-primed murine (balb/c) spleen cells in vitro by stimulation with the t cell mitogen concanavalin a or the t cell-dependent antigen ovalbumin (ova), respectively. inclusion of ae. aegypti sge in in vitro culture with naive cells caused significant suppression of the cytokines interleukin-2 (il-2) and interferon g ...19947985763
chromosomal mapping of two loci affecting filarial worm susceptibility in aedes aegypti.two quantitative trait loci (qtl) affecting susceptibility of the mosquito aedes aegypti to the filarial worm parasite brugia malayi were identified using restriction fragment length polymorphism (rflp) markers. the first locus, fsb[1,lf178], resides within a 10 cm interval on chromosome 1 and exhibits a recessive effect with respect to susceptibility. the second locus, fsb[2,lf98], resides within a 9 cm interval on chromosome 2 and exhibits an additive effect on susceptibility. significant epis ...19947987523
location of a lepidopteran specificity region in insecticidal crystal protein cryiia from bacillus thuringiensis.the bacillus thuringiensis insecticidal crystal protein cryiia has both high mosquito activity and gypsy moth activity; in contrast cryiib, which is 87% homologous, displays no mosquito activity and has a three-fold lower gypsy moth activity. the regions responsible for specificity against gypsy moth (lymantria dispar) and mosquito (aedes aegypti) larvae were located by introducing mlui and xhoi sites into homologous positions within the putative domain ii of both cryiia and cryiib genes, which ...19947997170
evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species.three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquito species: culex quinquefasciatus (filariasis) and aedes albopictus (dengue) (both laboratory and field strains); laboratory strains of aedes aegypti (dengue), anopheles stephensi and anopheles culicifacies (malaria), and culex tritaeniorhynchus (japanese encephalitis) in ind ...19937997809
use of the "cdc backpack aspirator" for surveillance of aedes aegypti in san juan, puerto rico.we constructed a battery-powered backpack aspirator to collect adult aedes aegypti mosquitoes. this simple, easily constructed aspirator facilitates the indoor collection of this important vector species. the collections made with the aspirator provide useful information about the biology and behavior of ae. aegypti that can be used in education and vector control programs and in the evaluation of ultra-low volume insecticide spray programs directed against this species. the cost for constructio ...19948014622
protozoan-enhanced toxicity of bacillus thuringiensis var. israelensis delta-endotoxin against aedes aegypti larvae.the toxicity of bacillus thuringiensis var. israelensis (bti) in mosquito larvae was enhanced by encapsulation in the protozoan tetrahymena pyriformis. aedes aegypti larvae which fed on t. pyriformis loaded with bti died about three times faster than when fed on the same concentrations of bti alone due to ingestion of higher toxin concentrations, reflected by shorter death times of exposed populations. the best larvicidal activities were achieved at ratios of cell/spore numbers in the range of 1 ...19948021522
community-based integrated control of aedes aegypti: a brief overview of current programs.dengue viruses are maintained in endemic transmission cycles in tropical urban areas where epidemics periodically occur. until about 30 years ago, there were long intervals (10-40 years) between epidemics but they are now occurring in many areas at 3-5-year intervals. these epidemics are most likely caused by virus strains with different epidemic potential. accompanying this increased frequency in epidemic activity has been a change in the disease pattern with cases of the severe form of dengue ...19948024084
purification of an insect defensin from the mosquito, aedes aegypti.using a new, sensitive assay of bacterial growth inhibition, inducible antibacterial activity has been identified in the haemolymph of the mosquito, aedes aegypti following inoculation with bacteria or with microfilariae of the filarial nematode brugia pahangi, but not after inoculation with sterile culture medium. a lower level of antibacterial activity has also been observed in untreated individual mosquitoes. following bacterial inoculation, a basic, inducible antibacterial peptide has been d ...19948025559
frequent occurrence of ige and igg4 antibodies against saliva of aedes communis and aedes aegypti mosquitoes in children.we examined the prevalence of ige and igg4 class antibodies to the saliva of aedes communis and aedes aegypti mosquitoes in the sera of three groups of exposed children using a sensitive immunoblot method. the frequencies of ige antibodies to the major 36-kd a. communis and a. aegypti saliva antigens ranged from 82 to 90% in the 20 finnish, 17 kenyan, and 20 mexican children. the corresponding igg4 antibody frequencies were 85, 41, and 20%, respectively. the nonexposed 20 icelandic children did ...19948038615
use of randomly amplified polymorphic dna amplified by polymerase chain reaction markers to estimate the number of aedes aegypti families at oviposition sites in san juan, puerto rico.we report the application of a molecular genetic technique to estimate the number of full-sibling families of aedes aegypti contained in oviposition traps. randomly amplified polymorphic dna amplified by the polymerase chain reaction markers were used to estimate the numbers and sizes of families in traps at field locations in san juan, puerto rico. forty-nine presumptive loci were amplified with five primers in a total of 813 individuals from 26 sites. the average family size was 10.95, but the ...19948059920
filaria vector competence of some anopheles species.the filaria vector competence of anopheles stephensi was compared with brugia-susceptible aedes aegypti liverpool strain, an. gambiae badagry lagos strain and an. dirus perlis malaysia strain. an. stephensi ingested more brugia pahangi microfilariae, had the highest infectivity rate and yielded more infective mosquitoes than the other two anopheline species. the overall vector competence of an. stephensi was 0.13 times that of ae. aegypti, 0.62 times that of an. gambiae and 2.17 times that of an ...19948066378
mutagenesis of two surface-exposed loops of the bacillus thuringiensis cryic delta-endotoxin affects insecticidal mutagenesis was used to determine the role of two surface-exposed loops (gly-317-phe-320 and gln-374-pro-377) in the insecticidal specificity of the bacillus thuringiensis cryic delta-endotoxin. mutant toxins were generated by pcr using degenerate oligonucleotide primers, and expressed in escherichia coli. more than 50 mutant toxins were screened for toxicity to the lepidopteran spodoptera frugiperda sf9 cell line using an in vitro lawn assay. a panel of these mutant toxins, which ...19948093015
cytotoxicity and adp-ribosylating activity of the mosquitocidal toxin from bacillus sphaericus ssii-1: possible roles of the 27- and 70-kilodalton peptides.clones expressing regions of the 100-kda bacillus sphaericus ssii-1 mosquitocidal toxin (mtx) as fusion proteins with glutathione s-transferase were constructed, and the toxin-derived peptides were purified. the in vitro adp-ribosylation activities of these peptides and their effects on larvae and cells in culture were studied. mtx25 (amino acids 30 to 493) was found to adp-ribosylate two proteins with molecular masses of 38 and 42 kda, respectively, in culex quinquefasciatus (g7) cell extracts, ...19938096838
effect of temperature on toxicity of two bioinsecticides spherix (bacillus sphaericus) and bactoculicide (bacillus thuringiensis) against larvae of four vector mosquitoes.two bioinsecticide preparations, viz. spherix (bacillus sphaericus) and bactoculicide (bacillus thuringiensis h-14), were tested in the laboratory against larvae of anopheles culicifacies, anopheles stephensi, culex quinquefasciatus and aedes aegypti at different temperatures. the lcs50 of spherix against iii instar larvae of these species at 27 +/- 2 degrees c were 2.0, 0.19, 0.05 and > 40 mg/litre, respectively and those of bactoculicide were 0.32, 0.16, 0.06 and 0.03 mg/litre, respectively. t ...19938100540
linkage map for aedes aegypti using restriction fragment length polymorphisms.we report construction of a genetic linkage map for the mosquito, aedes aegypti, based on restriction fragment length polymorphisms (rflps). the map consists of 50 dna markers that identify 53 loci covering 134 map units across three linkage groups. determination of linkage associations between rflp markers and several mutant marker loci allowed for partial integration of the rflp markers with an existing classical genetic linkage map for a. aegypti. the rflp markers include 42 random cdna clone ...19938101854
variation of larval susceptibility to lagenidium giganteum in three mosquito species.a significantly greater number of lagenidium giganteum zoospores were found encysting on the dorsal thoracic surface of anopheles gambiae larvae than on the larvae of aedes aegypti and culex pipiens. however, germ tube penetration in the cuticle of a. gambiae provoked an intense and diffuse melanization which encapsulated the fungus and protected 56% from death. although a small number of zoospores attach to and penetrate the cuticular surface of a. aegypti and c. pipiens approximately 99% of bo ...19938104999
intracellular development of subperiodic brugia malayi influenced by mosquito thoracic muscle cells.the in vitro development of 1-day-old intracellularly lodged larvae of brugia malayi cultured in infected excised thoraces of selected susceptible and refractory strains of aedes aegypti and anopheles quadrimaculatus was compared with larvae reared in vivo. in susceptible mosquitoes, both in vitro and in vivo, larvae developed normally and abnormally. in refractory mosquitoes this pattern of both normal and abnormal development was also observed, except that comparatively fewer larvae developed ...19938105000
dengue in the south-eastern region of brazil: historical analysis and epidemiology.the aim of the study is an historical analysis of the work undertaken by the public health organizations dedicated to the combat of the aedes aegypti, as well as an epidemiological study of persons with unexplained fever, with a view to evaluating the occurrence of dengue within the population. the mac-elisa, gac-elisa, hemagglutination inhibition, isolation and typage tests were used. organophosphate intoxication in agricultural workers was also assessed by measuring concentrations of seric cho ...19938115829
dengue: the risk to developed and developing countries.dengue viruses are members of the flaviviridae, transmitted principally in a cycle involving humans and mosquito vectors. in the last 20 years the incidence of dengue fever epidemics has increased and hyperendemic transmission has been established over a geographically expanding area. a severe form, dengue hemorrhagic fever (dhf), is an immunopathologic disease occurring in persons who experience sequential dengue infections. the risk of sequential infections, and consequently the incidence of d ...19948146129
larval diet, adult size, and susceptibility of aedes aegypti (diptera: culicidae) to infection with ross river virus.the relationship of larval nutrition and adult body size to the susceptibility of aedes aegypti (l.) to ross river virus infection was examined. large adult mosquitoes produced by feeding larvae a high-level diet consumed significantly more virus particles than did smaller mosquitoes. however, when a correction for body size was made, smaller mosquitoes were found to consume significantly more virus per unit of body weight. a host viremia of 2.4 log10 pfu/ml failed to infect mosquitoes of any si ...19948158614
control of larval aedes aegypti (diptera: culicidae) by cyclopoid copepods in peridomestic breeding containers.mesocyclops longisetus (thiébaud), mesocyclops thermocyclopoides harada, mesocyclops venezolanus dussart, and macrocyclops albidus (jurine) were tested for their effectiveness in controlling aedes aegypti (l.) larvae in a variety of containers around homes in el progreso, honduras. all four cyclopoid species killed > 20 larvae per cyclopoid per d under container conditions. m. longisetus was most effective, not only because it was the most voracious predator, but also because it survived best in ...19948158627
plasmodium gallinaceum: differential lysis of two developmental stages of malaria sporozoites by the alternative pathway of complement.during sporogonic development of plasmodium gallinaceum in the mosquito vector, two developmentally distinct sporozoite stages can be isolated. sporozoites obtained from oocysts in abdomens of mosquitoes 10 days after an infective blood meal are poorly infectious to the vertebrate host (chicken); days later, sporozoites isolated from mosquito salivary glands are highly infectious. in a first step toward understanding the physiologic basis of this developmentally regulated infectivity to the vert ...19948162961
the design of a community-based health education intervention for the control of aedes aegypti.this report describes the process used to develop locally appropriate educational materials and to implement the education component of a community-based aedes aegypti control program in merida, yucatan, mexico. the process is broken into five stages: formative research, developing recommendations for behavior change, development of educational messages, development and production of educational materials, and distribution of the materials. appropriate terminology and taxonomies for dengue were ...19948166346
complete nucleotide sequence and genomic organization of the aedes albopictus parvovirus (aapv) pathogenic for aedes aegypti larvae.we have cloned the replicative form of the aedes albopictus parvovirus (aapv) genome and determined the complete sequence of the viral strand. the sequence is 4176 nucleotides (nt) in length. the first 134 nt at the 3' end and the terminal 182 nt at the 5' end of the viral (minus) strand can both generate by folding and annealing of complementary sequences a typical terminal t-shaped structure although they differ in their sequence. three large open reading frames (orfs), each one in a different ...19948178459
[comparative study of larval and ovitrap efficacy for surveillance of dengue and yellow fever vectors].a comparative study of the efficiency of ovitraps and larval-traps was undertaken with a view to improving the entomological survey of vectors of dengue and yellow fever-aedes aegypti and aedes albopictus-in s. paulo state, brazil. the region studied is infected only by aedes albopictus, a species that keeps to wild habitats but colonizes artificial breeding grounds as well. the first part of the study was located in a periurban area of tremembé county were 3 hollon trees, 23 ovitraps and 5 larv ...19938209154
[aedes (stegomyia) aegypti l. and associated culicidae fauna in a urban area of southern brazil].some aspects of the ecology of eleven species of culicidae that were found breeding in recipients in an urban area of southern brazil are presented. a great variety of recipients were listed as efficient breeding sites. apparently aedes aegypti has been recently introduced into the region and was limited to two areas of the city. culex quinquefasciatus, cx. coronator, ae. aegypti, ae. fluviatilis e limatus durhamii were the predominant species.19938209165
effect of ivermectin on two filaria-vector pairs. brugia malayi-aedes aegypti; litomosoides sigmodontis-bdellonyssus bacoti.the effect of ivermectin was studied on two filaria-vector pairs, brugia malayi-aedes aegypti and litomosoides sigmodontis-bdellonyssus bacoti. the rodent hosts, respectively mastomys coucha and meriones unguiculatus, were treated with ivermectin doses of 0.05 mg/kg, or 0.2 mg/kg or 2 mg/kg. batches of vectors were fed on rodents, infected or not, treated or not, from h7 to d43 post-ivermectin. vector survival was observed and dissections were performed to study the filarial development. it appe ...19938215116
effect of a community-based aedes aegypti control programme on mosquito larval production sites in el progreso, honduras.this paper describes the results of a trial to assess the efficacy in reducing the density of larval production sites of utilizing community involvement in the planning and implementation of an aedes aegypti control programme, in a dengue-endemic city in honduras. in addition to a substantial increase in knowledge about dengue transmission and prevention, a relative reduction in ae. aegypti larval infestation indices was found in those city neighbourhoods where community involvement was utilized ...19938236387
insect blood meal studies using radiosodium 24na and 22na.rabbits were infused with 3.7 gbq (100 mci) of [24na]na ion in a 100-ml sodium carbonate solution. beta particles were detected using a tennelec counting system; background counts were 1.6 +/- 1 counts per minute (cpm). counts for one nanoliter of blood ranged from 22 to 30 cpm. blood volumes on the mouthparts of tabanids following a 15-sec interrupted feeding were estimated to be 12.5 nl for tabanus fuscicostatus, 10.8 nl for t. nigrovittatus and 6.12 nl for chrysops fuliginosus. estimates of t ...19938245935
oviposition response of aedes aegypti mosquitoes to different concentrations of hay infusion in trinidad, west indies.ovitraps containing various concentrations of hay infusion and tap water were exposed weekly in the field for 15 wk to determine the oviposition patterns of aedes aegypti. the results showed 10, 20, 60 and 80% hay infusions each attracted similar numbers of ae. aegypti eggs oviposited and egg occurrences. no repellent effect was observed. in another field study, significantly more eggs and egg occurrences were collected from 25 and 50% hay infusions and tap water. the differences in these result ...19938245947
blood-feeding patterns of aedes aegypti (diptera: culicidae) collected in a rural thai village.aedes aegypti (l.) were collected by aspiration once each week from in and around houses in a rural village in chachoengsao province. thailand, during may 1990 to june 1991. of the 1,230 specimens analyzed with a sandwich elisa, 73% reacted to one or more of the seven hosts which we tested. eighty-eight percent (789/896) of all detectable meals were identified as being from a single host (human). patent multiple meals (double and triple), of which one was always human, were detected in 7% (66/89 ...19938254642
laboratory demonstration of oviposition by aedes aegypti (diptera: culicidae) in covered water thailand, ceramic jars (135-200 liters) covered by aluminum lids commonly are used to store water for household use. in laboratory cages, gravid female aedes aegypti (l.) were able to enter and oviposit in a covered water jar. although the aluminum lid was not a complete barrier to gravid females, it reduced the number of eggs oviposited by 77%. a vertically oriented foam rubber ring which was compressed between the lip of the jar and the flange of the lid effectively sealed the jar against o ...19938254646
the gonotrophic status and diel pattern of entry to outdoor oviposition sites of female aedes aegypti (l.) (diptera: culicidae).experimental observations, made outdoors during the dry and wet seasons in trinidad, confirm earlier findings regarding the diel pattern of entry to ovitraps and oviposition there and the taking of more than one bloodmeal during a single gonotrophic cycle. for 6-h but not for 6-h exposure periods, significantly more eggs were laid in the morning peak during the dry season than during the wet season. at the study site females were encountered singly, and only in ovitraps that contained eggs. with ...19938257237
seasonal abundance of dengue vectors in manila, republic of the philippines.the dengue vectors aedes aegypti and ae. albopictus were surveyed within the city of manila from august 1985 to july 1987. survey techniques included ovitraps, indoor resting collections, fay traps, and larval surveys. aedes aegypti was the principal container breeder within the residential areas, while ae. albopictus predominated in cemeteries. the ovitrap was very effective in detecting the presence of ae. aegypti, but not in measuring population changes during the year. indoor resting and fay ...19938266245
codon usage patterns in chromosomal and retrotransposon genes of the mosquito anopheles gambiae.codon usage was compiled for fourteen chromosomal genes and four retrotransposons from the mosquito anopheles gambiae. variation exists among chromosomal genes in the degree of bias. the genes showing the highest bias are probably most highly expressed. in these genes, the base composition at the third codon position is much richer in g + c than is the overall coding sequence. thus, codon usage is biased toward g- or c-ending codons. codon usage in each retrotransposon is quite different, not on ...19938269095
dynamic life table model for aedes aegypti (diptera: culicidae): analysis of the literature and model development.the container-inhabiting mosquito simulation model (cimsim) is a weather-driven, dynamic life table simulation model of aedes aegypti (l.). it is designed to provide a framework for related models of similar mosquitoes which inhibit artificial and natural containers. cimsim is an attempt to provide a mechanistic, comprehensive, and dynamic accounting of the multitude of relationships known to play a role in the life history of these mosquitoes. development rates of eggs, larvae, pupae, and the g ...19938271242
dynamic life table model for aedes aegypti (diptera: culicidae): simulation results and validation.the container-inhabiting mosquito simulation model (cimsim) is a weather-driven, dynamic life table simulation model of aedes aegypti (l.) and similar nondiapausing aedes mosquitoes that inhabit artificial and natural containers. this paper presents a validation of cimsim simulating ae. aegypti using several independent series of data that were not used in model development. validation data sets include laboratory work designed to elucidate the role of diet on fecundity and rates of larval devel ...19938271243
sialokinin i and ii: vasodilatory tachykinins from the yellow fever mosquito aedes aegypti.the saliva of the mosquito aedes aegypti has previously been reported to contain a 1400-da peptide with pharmacological properties typical of a tachykinin. in the present study this vasodilator has been purified to homogeneity and found to consist of two peptides: sialokinin i, with the sequence asn-thr-gly-asp-lys-phe-tyr-gly-leu-met-nh2, and sialokinin ii, identical to sialokinin i except for an asp in position 1. these peptides are present in amounts of 0.62 and 0.16 pmol (711 and 178 ng), re ...19948278354
[outbreak of classical fever of dengue caused by serotype 2 in araguaiana, tocantins, brazil].we report the first outbreak of dengue fever caused by dengue 2 (den 2) in araguaina, tocantins state. four hundred people of 74 families, living at s. joão, araguaina sul and neblina districts were questioned and then bled, in order to obtain sera to test for anti-dengue antibodies. if a person was sick, a small quantity of blood was collected for virus isolation. the main clinical picture of disease was characterized by fever, headache, myalgias, arthralgias and skin rash. were obtained 1,105 ...19938284598
role of the cryivd polypeptide in the overall toxicity of bacillus thuringiensis subsp. israelensis.the gene encoding the cryivd protein of b. thuringiensis subsp. israelensis crystals was disrupted by in vivo recombination. the toxicity of the cryivd protein-free inclusions was similar to that of the wild-type crystals on anopheles stephensi larvae but was half the wild-type toxicity on culex pipiens and aedes aegypti larvae.19938285695
on the transmissibility of eperythrozoon suis by stomoxys calcitrans and aedes aegypti.the stable fly, stomoxys calcitrans (linnaeus), and the yellow fever mosquito, aedes aegypti (linnaeus), were utilized to determine their capability to transmit eperythrozoon suis splitter between swine. three groups of each insect in each trial were allowed to feed on a pig previously infected with e. suis and then transferred to susceptible splenectomized pigs. as a control, one group of each insect was fed on a non-infected pig and then transferred to a susceptible pig. stable flies were tran ...19938291187
stable transformation of mosquito cell lines using a hsp70::neo fusion gene.mosquito cell culture transfection will allow the advancement of genetic studies of these important disease-transmitting insects. towards this end, we report the generation of stably transformed aedes aegypti mos20 cells using a plasmid construct containing the tn5 neo gene, the drosophila melanogaster hsp70 promoter, an sv40 intron and poly adenylation sequence, and a pbr 322 backbone. the apparent frequency of transfection, as measured by transient resistance of cell colonies to geneticin (g41 ...19938293995
[the effect of water temperature on the action of bacterial insecticides against mosquito larvae].the ld50 logarithm of bacillus thuringiensis and b. sphaericus toxins effects on the larvae of aedes aegypti and culex pipiens is in inverse correlation with the water temperature. the influence of the temperature on the toxins effect on c. pipiens larvae is higher than that for a. aegypti larvae. similarly, b. sphaericus toxin effect depends on the water temperature to a greater measure than that of b. thuringiensis toxin. the authors predict a high efficacy of b. sphaericus-based insecticides ...19938336659
heterogeneity in patterns of malarial oocyst infections in the mosquito vector.oocyst prevalence and intensity have been recorded in 349 laboratory infections of anopheles stephensi with plasmodium berghei. intensity and prevalence of infection are shown to be predictably related. the structure and heterogeneity in the infections has been analysed with the objective of describing the biological mechanisms by which the observed negative binomial oocyst distributions are generated. the analysis has revealed that the most likely processes lie within the population dynamic eve ...19938341579
genetic maps of the sheep blowfly lucilia cuprina: linkage-group correlations with other dipteran genera.linkage data and revised genetic maps for 72 autosomal loci in lucilia cuprina are presented. comparison of the linkage relationships of biochemically and morphologically similar mutations in ceratitis capitata, drosophila melanogaster, and musca domestica supports the hypothesis that the major linkage elements have survived relatively intact during evolution of the higher diptera. the relationship of the linkage groups of the mosquito aedes aegypti to these species is less clear.19938349126
unreliable supply of potable water and elevated aedes aegypti larval indices: a causal relationship?we investigated the hypothesis that a deficient supply of piped water was causing a high prevalence of water storage containers, which in turn, become important aquatic habitats of aedes aegypti in a small town in venezuela. the house (71.2%) and breteau indices (229) were considerably elevated. prevalent positive containers were: metal drums, small disposable containers (bottles, tins, etc.), tires, house plants (flowers in vases and plants in pots with earth) and tanks. most people reported fr ...19938350076
identification of blood meals in aedes aegypti by antibody sandwich enzyme-linked immunosorbent assay.a comparative study of 3 elisa protocols was performed for host blood meal identification in aedes aegypti. in the sandwich-b elisa, which used a combination of heavy and heavy+light chain conjugates, specificity was improved to such a degree that conjugates no longer required cross-adsorption with heterologous sera. using the sandwich-b assay, human blood meals in laboratory reared ae. aegypti could be detected longer after feeding (100% at 32 h and 80% at 42 h) than with a direct assay (100% a ...19938350077
[a study on transmission of dengue virus by culex fatigans].patients with acute dengue fever within 2 days of onset were simultaneously bitten by culex fatigans, aedes aegypti and aedes albopictus, which were fed and incubated in the laboratory. isolation and quantitative assay of dengue virus and transmission experiment were conducted on specimens collected from 3 kinds of mosquitoes at different time. the result showed a positive rate of 5.13% (2/39) and an average viral titer of 2.41 logtcid50, for culex fatigans, which indicates that culex fatigans m ...19938353818
three simple devices for preventing development of aedes aegypti larvae in water jars.we developed three types of covers that are easily fabricated from plastic screen locally manufactured in thailand. the covers were designed to permit normal use of water jars for drinking, utility water uses, and water storage. tests of the covers in the laboratory and field demonstrated that they could completely prevent successful development of aedes aegypti (l.) in water jars. initial experience in a village setting demonstrated that these devices were readily manufactured and used in a com ...19938357077
temperature-induced refractoriness of aedes aegypti mosquitoes to infection with the filaria brugia pahangi. 19938369568
phototoxicity of (1h-indenyl)thiophenes.the (1h-indenyl)thiophene derivatives 2 and 3 were recently reported to be excellent singlet oxygen sensitizers, comparable to alpha-terthienyl (1). the phototoxicity of these compounds was compared, using human erythrocytes, aedes aegypti mosquito larvae, daphnia magna, and fish (fathead minnows, pimephales promelas). the known ranking of the photooxidation properties was found to be a good predictor of phototoxic properties in erythrocytes and mosquito larvae but not in daphnias. all three com ...19938378432
experimental infection of aedes aegypti (diptera: culicidae) by the oral route with sindbis virus.the infectivity, dissemination, and transmissibility of wild-type sindbis (sin) virus were studied in aedes aegypti (l). there was an initial decline in the viral titer of whole mosquitoes for 3 d after ingestion of virus, followed by a gradual increase to a maximal level by day 6. immunoperoxidase staining of ae. aegypti for viral antigen showed infection of midgut epithelial cells on day 1, of the fat body by day 3, and of the brain by day 4. by day 5, there was infection of the foregut, hindg ...19938384663
insecticide susceptibility status of anopheles stephensi, culex quinquefasciatus and aedes aegypti in panaji, and larval insecticidal tests conducted in panaji, goa, revealed that adults of an. stephensi were resistant to ddt (4.0%), dieldrin (0.4%) and malathion (5.0%). the larvae of an. stephensi were also resistant to ddt (2.5 mg/l) and malathion (3.125 mg/l). cx. quinquefasciatus adults were resistant to ddt, dieldrin, malathion and fenitrothion (1.0%), and larvae were highly resistant to ddt but showed low resistance to malathion and fenitrothion (0.125 mg/i). adults of ae. aegypti were resis ...19938405597
effects on toxicity of eliminating a cleavage site in a predicted interhelical loop in bacillus thuringiensis cryivb delta-endotoxin.when activated by treatment with mosquito (aedes aegypti) gut extract, the bacillus thuringiensis cryivb delta-endotoxin lysed a. aegypti cells in vitro. sds-page and n-terminal sequence determination showed that in addition to removal of the c-terminal half of the molecule, the activated toxin had undergone proteolytic cleavage at two internal regions producing 47-48-kda and 16-18-kda polypeptides. aligning the cryivb protein sequence with the crystallographic structure of the cryiiia toxin sug ...19938405934
dengue in gujarat state, india during 1988 & 1989.following the reports of epidemics of febrile illness from several rural and urban areas of gujarat state (india) in 1988, epidemiological investigations were carried out and dengue (den) virus activity was demonstrated in large cities such as surat and rajkot as well as several villages in sabarkantha district. two strains of dengue type-2 each were isolated from human sera from surat city and a village in sabarkantha district. six strains of dengue virus were isolated from aedes aegypti mosqui ...19938406637
genetic determinants of host ranges of bacillus sphaericus mosquito larvicidal toxins.the 51.4-kda-41.9-kda binary toxin produced by different strains of bacillus sphaericus shows differential activity toward culex quinquefasciatus, aedes atropalpus, and aedes aegypti mosquito larvae. the patterns of larvicidal activity toward all three mosquito species and growth retardation in a. aegypti have been shown to be due to the 41.9-kda protein. by using mutant toxins expressed in escherichia coli, insecticidal activity and growth retardation correlated with amino acids centered around ...19938419297
pgs28 belongs to a family of epidermal growth factor-like antigens that are targets of malaria transmission-blocking antibodies.although pgs28, a 28-kd surface protein of plasmodium gallinaceum oökinetes, was previously thought not to be a target of transmission-blocking antibodies, we found that polyclonal antisera to pgs28 completely blocked parasite infectivity to aedes aegypti mosquitoes. antisera raised against reduced pgs28 were less effective in blocking transmission than were antisera to nonreduced pgs28; thus, the target epitope(s) of transmission-blocking antibodies appears to be conformation dependent. in stag ...19938426118
lessons of aedes aegypti control in thailand.the incidence of dengue haemorrhagic fever (dhf) in thailand has increased cyclically since the first recognized outbreak in 1958. without an effective vaccine against dengue, and considering the clinical difficulty of treating dhf cases, vector control is needed to prevent dengue transmission. since the establishment of the who aedes research unit in 1964, continued since 1973 as the who collaborating centre at the department of medical research in bangkok, much operational research has been ca ...19938435481
critical review of aedes aegypti control programs in the caribbean and selected neighboring recent years the region of the americas has experienced increasing dengue activity with circulation of multiple virus serotypes. associated with this trend has been the occurrence of sporadic dengue hemorrhagic fever (dhf) cases and of dhf epidemics in both the caribbean and latin america. high vector infestation levels persist even though most countries in the caribbean conduct national aedes aegypti control programs and despite the fact that in some instances, expenditures exceed us$5 per c ...19938468568
effects of plant flavonoids and other allelochemicals on insect cytochrome p-450 dependent steroid hydroxylase activity.the plant flavonoids flavone, chrysin, apigenin, kaempferol, morin, quercetin, myricetin and phloretin were found to inhibit in a dose-dependent manner the cytochrome p-450 dependent ecdysone 20-monooxygenase activity associated with adult female aedes aegypti, wandering stage larvae of drosophila melanogaster, and fat body and midgut from prewandering and wandering stage last instar larvae of manduca sexta. the concentrations of these flavonoids required to elicit a 50% inhibition of the steroi ...19938485518
observations on the breeding habitats of aedes aegypti in calcutta following an episode of dengue haemorrhagic fever.a year-long (nov. 1990-oct. 1991) search for ae. aegypti larvae was made of all water containers in and around fixed 100 houses at bowbazar area in calcutta following an episode of dhf. out of 10151 containers searched, 615 (6%) were positive. masonry tanks were the major (64.2%) and preferred (17%) breeding sites of ae. aegypti. indoor containers (6.7%) were more conducive to breeding of the vector species than the outdoor ones (3%). breteau index showing wide variation (25 in december '90 to ' ...19938486410
[yellow fever epidemic in the extreme north of cameroon in 1990: first yellow fever virus isolation in cameroon].some two years ago, suspicious cases of yellow fever (yf) were reported in northern cameroon. a deadly epidemic broke out during the second half of the rainy season (from 15 september to 22 december 1990) with 180 known cases, of which 125 died. the real figures could have been between 5000 and 20,000 cases with between 500 and 1000 deaths. the affected area was within the yellow fever belt, which is situated around latitude 11 degrees north and 14 degrees east. in this mountainous area (altitud ...19938490979
growth and development of brugia pahangi larvae under various in vitro vitro culture methods were utilized to investigate specific nutritional requirements of brugia pahangi larvae. infective third-stage larvae (l3) isolated from aedes aegypti (liverpool) mosquitoes were cultured in nctc 135:imdm (ni) medium plus various types of serum under 5% co2/air and 5% co2/n2 atmospheres. larvae grew, developed, and molted to the fourth stage (l4); however, further growth and differentiation beyond the mid-l4 were minimal. serum supplementation was necessary to induce mol ...19938501596
[the culicidian fauna and its nuisance in kinshasha (zaire)].a public health study to inventory bloodsucking mosquitoes was conducted in kinshasa and its regions. 20 culicidian species were represented by 7 anopheles, 6 culex, 5 aedes and 2 mansonia. in general, the number of bites/man/night (b/m/n) was in average 141.5 of cx. quinquefasciatus, 60.1 of cx. antennatus, 21.1 of m. africana, 16.3 of an. gambiae and 7.7 of m. uniformis. the nuisance is different from region to other. culex quinquefasciatus is the most abundant and aggressive species in the ur ...19938504267
insecticide susceptibility status of certain populations of aedes aegypti mosquito from rural areas of maharashtra aegypti mosquitoes from rural areas of maharashtra state were subjected to insecticide bio-assays. all the populations showed resistance to ddt at larval and adult stages. no resistance to deltamithrin and malathion was detected at any stage. biochemical analysis of these mosquito populations showed that resistance to ddt was probably due to increase in the kinetics of glutathione s-transferase.19938505082
gametogenesis and sporogony of hepatozoon mocassini (apicomplexa: adeleina: hepatozoidae) in an experimental mosquito host, aedes aegypti.the sexual life cycle of the hemogregarine hepatozoon mocassini was studied in aedes aegypti, an experimental mosquito host, using transmission electron microscopy. gamonts were observed leaving the host snake erythrocyte as early as 30 min after mosquitoes ingested infected blood, and some gamonts had penetrated the gut epithelial cells by this time. six hours post-feeding, gamonts were identified within cells of the abdominal fat body. twenty-four hours post-feeding, gamonts were often entrapp ...19938508167
sustainable urban development and human health: septic tank as a major breeding habitat of mosquito vectors of human diseases in south-eastern nigeria.septic tank mosquitoes in abia state university okigwe, south-eastern nigeria were studied using exit traps between november 1988 and april 1989. the results were revealing and striking. apart from the common septic tank mosquitoes, culex p. quinquefasciatus, cu. cinereus and aedes aegypti, which have been previously commonly found breeding in ammonia and nitrate-rich waters of latrines and septic tanks, the other species, cu. horridus, cu. tigripes and aedes vittatus, have not been commonly rep ...19938508215
distribution of container-inhabiting aedes larvae (diptera: culicidae) at a dengue focus in thailand.a thai village with dengue transmission was surveyed for aedes aegypti (l.) and ae. albopictus (skuse) larvae at the end of the rainy season. all containers (1,819) in 186 households were surveyed, recording the presence of larvae, container type, level of water, kind of cover, and location. the number of positive containers was proportional to the total number of containers in a household. standard water jars (approximately 200 liters) contributed 57% and small water jars (< 100 liters) contrib ...19938510120
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