Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [resistance of insects to insecticides. molecular mechanisms and epidemiology]. | the aim of this paper is to indicate the main strengths which are involved in the spread of insecticide resistance genes. these forces are more or less well known in population genetics, there are: mutations which are involved in the creation of new alleles well adapted to insecticides; migration which is responsible for the geographical extension of resistance and selection which screened among the various alleles those which are best adapted in the geographical and ecological context. the biol ... | 1996 | 8952895 |
| duplication of the ace.1 locus in culex pipiens mosquitoes from the caribbean. | in culex pipiens mosquitoes, ache1 encoded by the locus ace.1 is the target of organophosphorus and carbamate insecticides. in several resistant strains homozygous for ace.1rr, insensitive ache1 is exclusively found. an unusual situation occurs in two caribbean resistant strains where each mosquito, at each generation, displays a mixture of sensitive and insensitive ache1. these mosquitoes are not heterozygotes, ace.1rs, as preimaginal mortalities cannot account for the lethality of both homozyg ... | 1996 | 8978907 |
| determination of ace.1 genotypes in single mosquitoes: toward an ecumenical biochemical test | the occurrence of two acetylcholinesterases, ache1 and ache2, in the mosquito culex pipiens has been recently documented. resistance to organophosphates and carbamates due to target insensitivity is the result of a qualitative change of only ache1, encoded by the ace.1 gene. because ache1 and ache2 differ in their sensitivity to inhibitors, ace.1 genotypes can be misclassified by previous tests. we describe a new rapid microplate test that allows unambiguous identification of ace.1 genotypes. th ... | 1996 | 8980036 |
| systematics of mosquito disease vectors (diptera, culicidae): impact of molecular biology and cladistic analysis. | the field of medical entomology, by nature of its association with problems of human health, has been conservative in its application of molecular and computer technologies to systematic research. recently, however, these methods have opened new interpretations for systematics of disease vectors. medically important insects, particularly mosquitoes, are among those more thoroughly described by conventional taxonomy, and thereby provide a secure framework for testing congruencies with molecular d ... | 1997 | 9017898 |
| identification of a gene for cyt1a-like hemolysin from bacillus thuringiensis subsp. medellin and expression in a crystal-negative b. thuringiensis strain. | a gene designated cyt1ab1, encoding a 27,490-da protein, was isolated from bacillus thuringiensis subsp. medellin (h30 serotype) by using an oligonucleotide probe corresponding to the cyt1aa1 gene. the sequence of the cyt1ab1 protein, as deduced from the sequence of the cyt1ab1 gene, was 86% identical to that of the cyt1aa1 protein and 32% identical to that of the cyt2aa1 protein from b. thuringiensis subsp. kyushuensis. the cyt1ab1 gene was flanked upstream by a p21 gene, in the same orientatio ... | 1997 | 9023925 |
| [experience in using traps for collecting the eggs deposited by the urban mosquito (culex pipiens)]. | egg-traps detect culex pipiens when other methods (mosquito recording in the premises, registration of its attacks and, interview with people) yield negative results. this allows one to assess the rates of its water reservoir occupation and breeding with regard to less time spent and greater hygienic efforts. in the place under study, c.pipiens females make their first cycle autogenously in the immediate vicinity of a breeding place and fly away only after termination of the first egg-laying. | 1996 | 9026666 |
| possible culex pipiens pallens control by improvement of flow rates in water channels of saga city, southwest japan. | water levels and flow rates (no. censuses with flow/no. censuses per year) were analyzed for 208 mosquito-productive and 422 mosquito-free channel segments during 1986-88 in saga city, southwest japan. mean water levels tended to be higher at mosquito-free segments than at mosquito-productive segments, but the differences were < 5 cm and usually not significant. flow rates exceeded 80% at 60-67% of mosquito-free segments. in contrast, flow rates were < 20% at 49-62% of mosquito-productive segmen ... | 1996 | 9046470 |
| cdna cloning, baculovirus-expression and kinetic properties of the esterase, e3, involved in organophosphorus resistance in lucilia cuprina. | resistance to organophosphorus insecticides (ops) in the sheep blowfly, lucilia cuprina, is associated with a non-staining phenotype of the carboxylesterase isozyme, e3 (e.c. 3.1.1.1). here, we show that a member of alpha-esterase multigene family, lc alpha e7, encodes e3. an lc alpha e7 cdna has been isolated from an op-susceptible strain and expressed in a baculovirus. the expressed product is the same as e3 in its electrophoretic mobility and preference for alpha-over beta-naphthyl acetate as ... | 1997 | 9061925 |
| contrasting levels of variability between cytoplasmic genomes and incompatibility types in the mosquito culex pipiens. | reproductive incompatibilities called cytoplasmic incompatibilities are known to affect a large number of arthropod species and are mediated by wolbachia, a maternally transmitted microorganism. the crossing relationships between strains of potential hosts define their incompatibility types and it is generally assumed that differences between strains of wolbachia induce different crossing types. among all the described host species, the mosquito, culex pipiens, displays the greatest variability ... | 1997 | 9061971 |
| [evidence of very high resistance to chlorpyrifos and permethrin in culex pipiens populations in tunisia]. | resistance to two organophosphorous insecticides (temephos and chlorpyrifos) and one pyrethrinoid (permethrin) was studied in larvae of five culex pipiens samples collected in gafsa, telalsa, sayada, monastir et sfax. large variations in the tolerance to these insecticides was observed between samples. gafsa sample was the most susceptible and disclosed little difference when compared to the susceptible reference strain. in contrast, at ld95 the resistance ratio (rr) was 8 folds with temephos, 9 ... | 1995 | 9092389 |
| californian hybrid zone between culex pipiens pipiens and cx. p. quinquefasciatus revisited (diptera:culicidae). | phallosome morphology (dv/d ratio) and allozyme variation were used to reexamine the transition from culex pipiens pipiens l. to cx. p. quinquefasciatus say, detected in california from the northern central valley to the mexican border of the united states of america. significant deficiency of heterozygotes was observed at the diagnostic locus mdhp-2 in populations from the central part of the hybrid zone. long tails of introgression were detected: populations from both north and south ends of t ... | 1997 | 9103754 |
| cross-resistance to pyrethroid and organophosphorus insecticides in the southern house mosquito (diptera:culicidae) from cuba. | a sample of the southern house mosquito, culex pipiens quinquefasciatus say, from cuba was subjected to lambda-cyhalothrin selection to evaluate the usefulness of this pyrethroid insecticide for mosquito control. high resistance developed after 6 generations of selection. little or no cross-resistance was observed to other pyrethroids (deltamethrin and cypermethrin), to a carbamate (propoxur) and to some organophosphates (chlorpyrifos and pirimiphos-methyl), but high cross-resistance was found t ... | 1997 | 9103771 |
| resistance to bacillus sphaericus involves different mechanisms in culex pipiens (diptera:culicidae) larvae. | field culex pipiens pipiens (l.) mosquitoes that were collected after a control failure with spherimos in southern france developed high resistance (> 10,000-fold) to bacillus sphaericus crystal toxin after < 8 generations of laboratory selection. we show that this resistance is encoded by a single major recessive gene on linkage group i at 22.1 recombination units from the sex locus, and that it is not associated with any loss of binding affinity between brush border membrane fractions and the ... | 1997 | 9151498 |
| analysis of molecular forms and pharmacological properties of acetylcholinesterase in several mosquito species. | two acetylcholinesterases (ache1 and ache2) have recently been characterized in the common mosquito culex pipiens. this situation appeared to be an exception among insects, where only one acetylcholinesterase gene had previously been repeatedly reported. in the present study, acetylcholinesterase was studied in five mosquito species: aedes aegypti, anopheles gambiae, anopheles stephensi, culiseta longeareolata and culex hortensis, in order to test whether or not two different acetylcholinesteras ... | 1997 | 9185166 |
| a polymerase chain reaction-based assay for detection of wuchereria bancrofti in human blood and culex pipiens. | human blood samples and indoor-resting culex pipiens were collected in 33 randomly selected houses from different sectors of a village in the nile delta of egypt which was endemic for wuchereria bancrofti. blood was also collected from subjects with no history of living in filarial endemic areas. human blood samples were divided and assessed by both membrane filtration and polymerase chain reaction (pcr). similarly, mosquito samples were assessed by both dissection and pcr. blood pools represent ... | 1997 | 9196756 |
| detection of expressed chloramphenicol acetyltransferase in the saliva of culex pipiens mosquitoes. | mosquito salivary glands play an important role in the transmission of arthropod-borne pathogens. the ability to express genes in mosquitoes would be a powerful approach to characterize salivary gland genes, and to reveal important vector determinants of pathogen transmission. here we report the use of a double subgenomic sindbis (dssin) virus, designated te/3'2j/cat, and a packaged sindbis replicon virus, designated rep5/cat/26s, to express chloramphenicol acetyltransferase (cat) protein in the ... | 1997 | 9219368 |
| esterases a5-b5 in organophosphate-resistant culex pipiens from italy. | culex pipiens mosquitos from lignano city, udine province, northeast italy, were found to carry over-produced non-specific esterases a1, a2-b2 and a4-b4 or a5-b5, detected by starch gel electrophoresis, giving multiple resistance to organophosphorus insecticides. in order to differentiate between a4-b4 and a5-b5 esterases, the latter known only from cyprus whereas the former is widespread in italy and elsewhere, restriction fragment length polymorphism (rflp) analysis was performed at the estera ... | 1997 | 9226639 |
| success against lymphatic filariasis. | a campaign against lymphatic filariasis began in china's shandong province during 1956. epidemiological surveillance since 1984 indicates that the transmission of infection has been interrupted. the factors accounting for this are discussed and the continuing challenges presented by the disease are outlined. | 1997 | 9233057 |
| seasonal abundance and distribution of mosquitoes at a rural waste tire site in illinois. | the species composition, abundance, and distribution of mosquito larvae in tires were determined on 3 dates at a relatively large rural tire dump (about 300,000 tires) in southeastern il (jasper county). several observations at this site differed from those in previous reports about mosquitoes in tireyards, including 1) a relatively high percentage of tires positive for aedes triseriatus larvae in an open-field area, 2) a greater abundance of culex pipiens than cx. restuans in late-season collec ... | 1997 | 9249660 |
| application of deltamethrin-impregnated bednets for mosquito and malaria control in yunnan, china. | the results of research in china in recent years show that: 1) different laboratory sensitivity of adult anopheles minimus, an. sinensis and culex pipiens quinquefasciatus to deltamethrin exist in yunnan. although the range and duration for the use of permethrin and deltamethrin was limited, resistance of an. minimus, an. sinensis and cx. pipiens quinquefasciatus to different extent in some areas existed. 2) on walls built with cement and covered with a thin layer of lime on which deltamethrin a ... | 1996 | 9280005 |
| binding kinetics of bacillus sphaericus binary toxin to midgut brush-border membranes of anopheles and culex sp. mosquito larvae. | direct-binding assays and homologous-competition assays were used to identify specific binding between the radiolabelled toxin of bacillus sphaericus and brush-border membrane fractions (bbmf) from anopheles gambiae and anopheles stephensi, obtained from whole larvae preparations. in both species, the toxin bound to a single class of receptors. bbmf of a. gambiae had the highest binding affinity for the toxin of the species tested, with a dissociation constant (kd) of 30 +/- 15 nm and a maximum ... | 1997 | 9288894 |
| [the relation of the degree of water salinity to oviposition by female blood-sucking mosquitoes]. | anopheles sacharovi, an. atropatvus, an. pulcherrimus, an. superpictus. an. stephensi, culex pipiens females to prefer fresh water for their oviposition. the differences between them are that the an.stephensi and culex pipiens avoid high salinity values more frequently than other species. the eggs of a all the species studied do not survive at 2% salinity. the an. sacharovi eggs are more resistant to salinity while the an. pulcherrimus ones are less resistant. nevertheless, the females of all th ... | 1997 | 9304030 |
| [the search for insecticides for use in "egg traps" for culex pipiens mosquitoes (diptera, culicidae). 1. icon]. | laboratory experiments have shown, that mosquitoes fly into eggs trap not only at eggs laying. icon has not attractive and repellent to mosquitoes. in dose 0.5 g/m2 the effect of a icon is persisting during as a minimum of 100 days. icon is suitable for use in eggs trap for culex pipiens. | 1997 | 9304031 |
| esterase gene amplification in culex pipiens. | in the mosquito culex pipiens one of the major resistance mechanisms to organophosphorous pesticides (ops) is increased detoxification of insecticide. this resistance is the consequence of overproduction of two types of esterases, esterases a and b, coded at two loci, est-3 (a esterase) and est-2 (b esterase). we have analysed the genomic structure of these genes in different strains resistant to ops and have attempted to characterize the different types of mutations leading to the resistant phe ... | 1997 | 9359574 |
| contribution of the 65-kilodalton protein encoded by the cloned gene cry19a to the mosquitocidal activity of bacillus thuringiensis subsp. jegathesan. | two new crystal protein genes, cry19a and orf2, isolated from bacillus thuringiensis subsp. jegathesan were cloned and characterized. the cry19a gene encodes a 74.7-kda protein, and the orf2 gene encodes a 60-kda protein. cry19a contains the five conserved blocks present in most b. thuringiensis delta-endotoxins. the orf2 amino acid sequence is similar to that of the carboxy terminus of cry4 proteins. the cry 19a gene was expressed independently or in combination with orf2 in a crystal-negative ... | 1997 | 9361431 |
| mosquitoes as vectors of setaria labiatopapillosa. | an infected bovine-baited trap was utilised in summer 1994 to catch possible intermediate hosts of s. labiatopapillosa in northeastern italy. collections were made for 21 nights from 8.00 p.m. to 6.00 a.m. every 2 h and, after 12 september, every 30 min. among the 16,159 mosquitoes sampled, 11,052 were freshly blood-fed. most of the unfed females and a representative sample of those which had fed were identified as follows: culex pipiens, aedes caspius, a. vexans, culiseta annulata, anopheles ma ... | 1997 | 9363488 |
| binding of the 51- and 42-kda individual components from the bacillus sphaericus crystal toxin to mosquito larval midgut membranes from culex and anopheles sp. (diptera: culicidae). | individual components (p51 and p42) from the crystal toxin (bin) of bacillus sphaericus were used for in vitro binding competition experiments with brush border membranes (bbmfs) from culex pipiens and anopheles gambiae larval midguts. p51 competed for the bin binding site with a similar affinity to the bin toxin, on both bbmfs. for c. pipiens, p42 bound non-specifically until p51 was added with maximum binding of p42 at a molar ratio of each component. the binding of p42 was much greater on a. ... | 1997 | 9368375 |
| development of a polymerase chain reaction assay for differentiation between culex pipiens pipiens and cx. p. quinquefasciatus (diptera: culicidae) in north america based on genomic differences identified by subtractive hybridization. | culex pipiens is a complex of mosquitoes that are involved in the transmission of pathogens, including st. louis encephalitis virus in north america. the 2 major taxa in the complex, cx. p. pipiens and cx. p. quinquefasciatus, are nearly identical morphologically, making identification of field-collected specimens difficult, and attempts at differentiation based on biochemical and molecular techniques have been unsuccessful. we report here the use of genomic subtractive hybridization to identify ... | 1997 | 9379458 |
| wolbachia, normally a symbiont of drosophila, can be virulent, causing degeneration and early death. | wolbachia, a maternally transmitted microorganism of the rickettsial family, is known to cause cytoplasmic incompatibility, parthenogenesis, or feminization in various insect species. the bacterium-host relationship is usually symbiotic: incompatibility between infected males and uninfected females can enhance reproductive isolation and evolution, whereas the other mechanisms enhance progeny production. we have discovered a variant wolbachia carried by drosophila melanogaster in which this cozy ... | 1997 | 9380712 |
| variation of dominance of newly arisen adaptive genes. | newly arisen adaptive alleles such as insecticide resistance genes represent a good opportunity to investigate the theories put forth to explain the molecular basis of dominance and its possible evolution. dominance levels of insecticide resistance conferred by insensitive alleles of the acetylcholinesterase gene were analyzed in five resistant strains of the mosquito culex pipiens. dominance levels were found to differ between strains, varying from partial recessivity to complete dominance. thi ... | 1997 | 9383065 |
| international indoor and outdoor evaluation of bacillus sphaericus products: complexity of standardizing outdoor protocols. | only one bacillus sphaericus strain, strain 2362, is currently used commercially to control culex larval populations. a reliable methodology, easily used, was developed to identify new strains for field application. larvicidal activities of 3 highly mosquitocidal strains, strains c3-41, mal, and lb24, previously selected in the laboratory, were compared with that of strain 2362 in tropical and european countries. the following steps were performed: production and titration of acetonic powders fr ... | 1997 | 9383761 |
| development of wuchereria bancrofti in culex pipiens l. (diptera: culicidae) exposed in the larval instar to sublethal dosages of insecticides and one insect growth regulator and their influence on reproduction of filaria-infected mosquitoes. | the effects of exposure of culex pipiens larvae to sublethel concentrations of larvicides on uptake, development of wuchereria bancrofti, survival rate and reproduction of filaria-infected mosquitoes were investigated. fourth instar larvae of cx. pipiens were exposed to lc40 of the surfactant triton x-100, the insect growth regulator dpx alone or combined with lc10 of the surfactant and permethrin alone or combined with lc10 of the surfactant. adults that survived insecticide treatments and cont ... | 1997 | 9425827 |
| effect of wuchereria bancrofti (cobbold infection on the biological activities of culex pipiens l. (diptera: culicidae) in egypt. | the impact of moderate infection with wuchereria bancrofti (cobbold) (25 mf/50 microliters blood) on the biological activities of culex pipiens l. were investigated. data revealed that w. bancrofti parasites did not interfere significantly with the oviposition rate (81.97%, 80.228% in non-infected and infected mosquitoes, respectively), fecundity (73.56 +/- 4.56 and 74.23 +/- 5.05 eggs/female) duration of the gonotrophic cycle (6.34 +/- 0.29 and 6.05 +/- 0.26 days), or egg hatchability (88.06% a ... | 1997 | 9425829 |
| distribution of organophosphate and carbamate resistance in culex pipiens quinquefasciatus (diptera: culicidae) in west africa. | the distribution of organophosphate and carbamate resistance was investigated in 33 samples of culex pipiens quinquefasciatus say from 25 cities in côte d'ivoire and burkina faso. organophosphate resistance levels were higher in côte d'ivoire than in burkina faso. chlorpyrifos resistance ratios at lc95 ranged from 4 to 30 times in côte d'ivoire and from 3 to 6 times in burkina faso. for temephos, ratios ranged from 3 to 18 and from 1 to 2, respectively. of 27 samples from côte d'ivoire, 25 also ... | 1997 | 9439121 |
| cm-gag, a transposable-like element reiterated in the genome of culex pipiens mosquitoes, contains only a gag gene. | cm-gag elements constitute an homogeneous family of sequences that are reiterated in the genome of culex pipiens strains from different continents. apparently complete 1.75 kb cm-gag copies are flanked by target-site duplications and have a polyadenylation signal near their 3' end. they potentially contain a unique gene encoding a putative protein that displays homologies with nucleic acid binding proteins and the gag polypeptide of retroviruses and retrotransposons, but that does not encode a r ... | 1997 | 9440266 |
| studies on the transmission potential of surviving microfilaremias after basic control of filariasis. | after filariasis was basically controlled (the microfilarial rate was lower than 1%) in henan province in 1987, longitudinal observation of the disease has been carried out in all the province in order to study the regular pattern of growth and decline or the transmission potential of the disease. according to the distribution of filaria species and original microfilarial rate, 7 administrative villages in 7 counties were selected as surveillance sites. from 1988 to 1995, etiological and mosquit ... | 1997 | 9444011 |
| analysis of a mosquito acetylcholinesterase gene promoter. | insect acetylcholinesterase is the target site for organophosphorus and carbamate insecticides and point mutations in the ace gene are associated with resistance in drosophila melanogaster and musca domestica. however, little is known of the genetic regulation of insect ace genes. here we report the isolation of four different cdnas from an aedes ace locus and identification of the gene promoter. northern analysis reveals two large (>10 kb) transcripts and one smaller transcript of 4 kb. the reg ... | 1998 | 9459425 |
| [resistance to organophosphate insecticides in culex pipiens l. (diptera: culicidae) and first signal of the presence of a5-b5 esterase in italy]. | after a short review on insecticide resistance in mosquitoes, the results of a study on organophosphate (op) resistance, carried out on 2 culex pipiens l. field populations from north-eastern italy, are reported. the a1 an a4-b4 or a5-b5 esterases were detected in our sample by starch gel electrophoresis. in order to differentiate between a4-b4 and a5-b5 esterases, restriction fragment length polymorphism (rflp) analysis at the esterases b locus was performed: both a4-b4 and a5-b5 aplotipes were ... | 1997 | 9470248 |
| field trials of vectolex cg, a bacillus sphaericus larvicide, in illinois waste tires and catch basins. | the susceptibilities of aedes triseriatus (say), anopheles punctipennis (say), culex restuans (theobald), and culex pipiens (l.) larvae to vectolex cg were determined. vectolex, formulated on corncob granules (10-14 mesh) was applied to 2 tire dumps and numerous catch basins located in east-central illinois. vectolex, formulated as effervescent tablets, was also applied to catch basins. in a sunlit dump, there was a 99.6% reduction in ae. triseriatus, cx. restuans, and cx. pipiens larvae as long ... | 1997 | 9474554 |
| study on the flying height of aedes caspius and culex pipiens females in the po delta area, italy. | we have studied the vertical distribution of culicidae in the "ancona di bellocchio" protected area (regional park of the po delta, emilia-romagna, italy) by means of nonilluminated cdc traps baited with co2. traps were placed at heights of 1.5, 3, 4, and 5 m from the ground in open areas and at 1.5, 3, 4, 5, 6, and 7 m in wooded areas. we calculated the average flying height of the species caught, i.e., in order of decreasing flying height, culex pipiens linnaeus s.l., culex modestus ficalbi, c ... | 1997 | 9474562 |
| differences in haemagglutination activity in autogenous and anautogenous members of the culex pipiens mosquito complex. | hemagglutination activity was studied in whole body extracts of seven laboratory strains of culex pipiens s.l. (culex pipiens molestus and culex pipiens quinquefasciatus). no significant differences in titer between females were observed, but hemagglutination activity in males differed depending on the feeding regime of the mothers of the males. | 1997 | 9491358 |
| variability among tunisian populations of culex pipiens: genetic structure and susceptibility to a filarial parasite, brugia pahangi. | culex pipiens pipiens is a common mosquito found in north africa and is the primary vector of bancroftian filariasis in egypt. experimental infections with c. p. pipiens have demonstrated that this species supports brugia pahangi development (parasitic yield 6.3%). in addition, the genetic variation among c. p. pipiens populations from ben arrous (in the suburb of tunis) estimated from isoenzyme polymorphism of five neutral genes (pgm, gpi, hk1, got-1, and got-2) was slight (fst = +0.083). c. p. ... | 1998 | 9493214 |
| pleiotropy of adaptive changes in populations: comparisons among insecticide resistance genes in culex pipiens. | resistance to toxicants is a convenient model for investigating whether adaptive changes are associated with pleiotropic fitness costs. despite the voluminous literature devoted to this subject, intraspecific comparisons among toxicant resistance genes are rare. we report here results on the pleiotropic effect on adult survival of culex pipiens mutants involved in the same adaptation: the resistance to organophosphorus insecticides. this field study was performed in southern france where four re ... | 1997 | 9494436 |
| isolation of the spirochaete borrelia afzelii from the mosquito aedes vexans in the czech republic. | during the years 1993-1995, a total of 3580 culicine mosquitoes of six species were collected in south moravia, czech republic, and examined by dark-field microscopy for the presence of borreliae. females of aedes cantans, ae. sticticus, ae. vexans, culex pipiens and cx pipiens biotype molestus (but not ae. geniculatus or culiseta annulata) harboured spirochaetes, the frequencies ranging from 0.7% to 7.8%. one isolate (br-53) from ae. vexans was identified as borrelia afzelii genospecies. the po ... | 1998 | 9513946 |
| investigation of haematophagous arthropods for borreliae--summarized data, 1988-1996. | blood-sucking arthropods, collected in south moravia, czech republic, were examined by darkfield microscopy for borreliae from 1988 to 1996. among host-seeking ixodid ticks (8481 ixodes ricinus (l.), 372 dermacentor reticulatus (fabr.), 167 haemaphysalis concinna koch), borreliae were only observed in adult (23.2%), nymphal (17.2%) and larval (6.3%) i. ricinus. the prevalence of borreliae in i. ricinus did not vary considerably among habitats except for lower values in agroecosystems, xerothermi ... | 1998 | 9516997 |
| a sex-linked ace gene, not linked to insensitive acetylcholinesterase-mediated insecticide resistance in culex pipiens. | an acetylcholinesterase (ache) gene, ace.x, showing 93% identity of deduced amino acid sequence to anopheles stephensi ace has been cloned from a culex pipiens strain homozygous for insensitive ache (iache) mediated insecticide resistance. dna sequence of genomic dna clones identified exons 2-5. rflp of six clones indicated four possible alleles. linkage analysis located ace.x to chromosome i, less than 0.8 centimorgans from the sex locus, whereas the locus conferring resistance was 2.0 centimor ... | 1998 | 9535157 |
| deleterious mutations destabilize ribosomal rna in endosymbiotic bacteria. | in populations that are small and asexual, mutations with slight negative effects on fitness will drift to fixation more often than in large or sexual populations in which they will be eliminated by selection. if such mutations occur in substantial numbers, the combined effects of long-term asexuality and small population size may result in substantial accumulation of mildly deleterious substitutions. prokaryotic endosymbionts of animals that are transmitted maternally for very long periods are ... | 1998 | 9539759 |
| germination, growth, and sporulation of bacillus thuringiensis subsp. israelensis in excreted food vacuoles of the protozoan tetrahymena pyriformis. | spores of bacillus thuringiensis subsp. israelensis and their toxic crystals are bioencapsulated in the protozoan tetrahymena pyriformis, in which the toxin remains stable. each t. pyriformis cell concentrates the spores and crystals in its food vacuoles, thus delivering them to mosquito larvae, which rapidly die. vacuoles containing undigested material are later excreted from the cells. the fate of spores and toxin inside the food vacuoles was determined at various times after excretion by phas ... | 1998 | 9572947 |
| resistance to organophosphorus and pyrethroid insecticides in culex pipiens (diptera: culicidae) from tunisia. | resistance to the organophosphates temephos and chlorpyrifos, the carbamate propoxur, the pyrethroid permethrin, and the organochloride ddt was investigated in tunisian populations of culex pipiens pipiens (l.) collected between 1990 and 1996. resistance to temephos was uniformly low, reaching 10-fold in the most resistant population. in contrast, resistance to chlorpyrifos was highly variable, reaching the highest level (> 10,000-fold) recorded worldwide. the chlorpyrifos-resistant populations ... | 1998 | 9615543 |
| mosquito feeding-induced enhancement of cache valley virus (bunyaviridae) infection in mice. | cache-valley (cv) virus, an arthropod-borne bunyavirus, recently has emerged as a significant veterinary pathogen causing infertility and congenital malformations in north american ruminants. to investigate the role of vector feeding on cv infection, adult mice were injected subcutaneously with cv, cv and vector thorax extract (a source of vector saliva), or cv into the site of intense, noninfected-mosquito feeding. mice did not become infected after injection of cv or cv and vector saliva, nor ... | 1998 | 9615544 |
| multiple isolations of eastern equine encephalitis and highlands j viruses from mosquitoes (diptera: culicidae) during a 1996 epizootic in southeastern connecticut. | thirty-six isolations of eastern equine encephalitis virus were obtained from 8 species of mosquitoes collected from 5 september through 18 october 1996 during an epizootic in southeastern connecticut. these included culiseta melanura (coquillett) (19 isolates), culex pipiens l. (8), culiseta morsitans (theobald) (3), aedes sollicitans (walker) (2), aedes cantator (coquillett) (1), aedes trivittatus (coquillett) (1), aedes vexans (meigen) (1), and coquillettidia perturbans (walker) (1). isolatio ... | 1998 | 9615549 |
| insecticidal activity of bacillus laterosporus. | the bacillus laterosporus strains 921 and 615 were shown to have toxicity for larvae of the mosquitoes aedes aegypti, anopheles stephensi, and culex pipiens. the larvicidal activity of b. laterosporus was associated with spores and crystalline inclusions. purified b. laterosporus 615 crystals were highly toxic for aedes aegypti and anopheles stephensi. | 1998 | 9647857 |
| insecticidal and antifungal activities of aminorhodanine derivatives. | aminorhodanine (1) showed strong insecticidal activity against culex pipiens pallens and musca domestica, with respective ld50 values of 0.21 microgram/insect and 0.87 microgram/insect. compound 1 had antifungal activity against aspergillus niger atcc-16404, trichophyton mentagrophytes ifo-32412, candida albicans atcc-10231, hansenula anomala ops-308 and penicillium expansum ifo-8800. in particular, 1 had potent antifungal activity against aspergillus niger atcc-16404, its minimal inhibitory con ... | 1998 | 9648238 |
| evaluating gene flow using selected markers: a case study. | the extent to which an organism is locally adapted in an environmental pocket depends on the selection intensities inside and outside the pocket, on migration, and on the size of the pocket. when two or more loci are involved in this local adaptation, measuring their frequency gradients and their linkage disequilbria allows one to disentangle the forces-migration and selection-acting on the system. we apply this method to the case of a local adaptation to organophosphate insecticides in the mosq ... | 1998 | 9649528 |
| polymorphisms and fluctuations in copy number of amplified esterase genes in culex pipiens mosquitoes. | in culex pipiens mosquitoes, a2 esterase alleles are co-amplified with b2 esterase alleles in response to selection with organophosphate insecticides. in this study the amplified a2 and b2 sequences were compared between twelve strains from four continents by restriction mapping. the restriction maps were almost identical in each strain throughout 22 kb surrounding the genes, suggesting that this represents a constant core sequence. a polymorphism was found in two strains collected from egypt an ... | 1998 | 9662480 |
| characterization of mosquito larvicidal parasporal inclusions of a bacillus thuringiensis serovar higo strain. | the parasporal inclusion proteins of the type strain of bacillus thuringiensis serovar higo (h44), that have moderate mosquitocidal activity, were characterized. the purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, culex pipiens molestus and anopheles stephensi and the moth-fly, telmatoscopus albipunctatus. the lc50 values of the inclusion for the two mosquitoes were 3.41 and 0.15 microgram.ml-1, respectively. no mortality was shown ... | 1998 | 9674143 |
| distribution, serological identification, and pcr analysis of bacillus thuringiensis isolated from soils of korea. | a total, 58 strains of bacillus thuringiensis were isolated from soils of various regions in korea. serological tests showed that b. thuringiensis isolates represented 10 h serotypes, indicating a varied flora of b. thuringiensis. but the h serotypes did not have a significantly uneven distribution, ranging from 1 to 11 isolates. in toxicity tests, 35% of all isolates were toxic to lepidoptera, 20% were toxic to diptera, and 9% were non-toxic isolates. especially, a large number of lepidopteran/ ... | 1998 | 9688820 |
| estimation of genetic divergence and gene flow between culex pipiens and culex quinquefasciatus (diptera: culicidae) in argentina. | allele frequencies at seven polymorphic loci controlling the synthesis of enzymes were analyzed in six populations of culex pipiens l. and cx. quinquefasciatus say. sampling sites were situated along a north-south line of about 2,000 km in argentina. the predominant alleles at mdh, idh, gpdh and gpi loci presented similar frequencies in all the samples. frequencies at the pgm locus were similar for populations pairs sharing the same geographic area. the loci cat and hk-1 presented significant ge ... | 1998 | 9698844 |
| ultrastructural features of cystic and merogonic stages of hepatozoon sipedon (apicomplexa: adeleorina) in northern leopard frogs (rana pipiens) and northern water snakes (nerodia sipedon) from ontario, canada. | the cystic and merogonic stages of the haemogregarine hepatozoon sipedon, infecting northern water snakes (nerodia sipedon sipedon) and northern leopard frogs (rana pipiens), respectively, in ontario, canada, were investigated by transmission electron microscopy. cysts, which were observed in the liver of northern leopard frogs (rana pipiens) after these anurans ingested mosquitoes (culex pipiens) containing oocysts of the parasite, harboured two cystozoites, each of which contained a large crys ... | 1998 | 9703677 |
| a novel class of mosquitocidal delta-endotoxin, cry19b, encoded by a bacillus thuringiensis serovar higo gene. | partially digested hincii fragments of dna from a mosquitocidal strain of bacillus thuringiensis serovar higo were cloned into pbluescript ii sk(+) and propagated in escherichia coli. recombinant cells were screened immunologically for the production of parasporal inclusion antigens. one e. coli clone harboring a recombinant plasmid exhibited larvicidal activity to culex pipiens molestus, but not to anopheles stephensi. hybridization experiments revealed that the gene of the toxin protein is loc ... | 1998 | 9704107 |
| response of mosquitoes (diptera: culicidae) to carbon dioxide and octenol in egypt. | carbon dioxide and 1-octen-3-ol (octenol were evaluated individually, and in combination, as adult mosquito attractants at two sites in qara, matruh governorate, egypt. four mosquito species were collected during the study: aedes caspius, anopheles multicolor, an. sergenti and culex pipiens. anopheles multicolor and cx. pipiens were collected in insufficient numbers to allow statistical analysis. significantly greater numbers of ae. caspius and an sergenti were collected in co2 and co2 + octenol ... | 1998 | 9707659 |
| insecticidal properties of citrus oils against culex pipiens and musca domestica. | peel oils of lemon, grapefruit and navel orange were tested for insecticidal activities against larvae and adults of culex pipiens and musca domestica. lemon peel oil was the most effective against larvae and adults of c. pipiens. grapefruit peel oil was more toxic to adults of m. domestica while lemon oil, was more toxic musca larvae. on the other hand, the orange peel oil was the least effective against larvae and adults of both species. the toxicity of oils applied to larval stages was extend ... | 1998 | 9707687 |
| bacillus thuringiensis and its pesticidal crystal proteins. | during the past decade the pesticidal bacterium bacillus thuringiensis has been the subject of intensive research. these efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism's pesticidal crystal proteins, and a coherent picture of these relationships is beginning to emerge. other studies have focused on the ecological role of the b. thuringiensis crystal proteins, their performance in agricultural and othe ... | 1998 | 9729609 |
| west nile encephalitis epidemic in southeastern romania. | west nile fever (wnf) is a mosquito-borne flavivirus infection endemic in africa and asia. in 1996, the first major wnf epidemic in europe occurred in romania, with a high rate of neurological infections. we investigated the epidemic to characterise transmission patterns in this novel setting and to determine its origin. | 1998 | 9737281 |
| a novel isolate of bacillus thuringiensis serovar leesis that specifically exhibits larvicidal activity against the moth-fly, telmatoscopus albipunctatus. | a soil isolate designated 88-ko-14-45, belonging to bacillus thuringiensis serovar leesis (h33), exhibited larvicidal activity against the moth-fly, telmatoscopus albipunctatus (diptera: psychodidae), but not for larvae of the culicine and aedine mosquitoes and lepidoptera. purified parasporal inclusions had an lc50 value of 5.78 micrograms/ml for the larval moth-fly, but gave no mortality against larvae of culex pipiens molestus (diptera: culicidae) at protein concentrations up to 10 mg/ml. ele ... | 1998 | 9741119 |
| the mosquitoes (diptera: culicidae) in the area of the middle course of the river someşul mare (romania): faunistical and ecological data. | the larval and adult mosquito populations in the locality salva and its surroundings on the middle course of the river someşul mare were investigated from march to october 1994. 17 mosquito species (11 as larvae and 13 as adults) were recorded: aedes cataphylla, aedes cantans aedes leucomelas, aedes dorsalis, aedes caspius, aedes vexans, aedes flavescens, aedes cinereus, aedes annulipes, aedes geniculatus, culex modestus, culex pipiens, culex territans, culiseta alaskaensis, anopheles maculipenn ... | 1998 | 9745338 |
| the introduction into bacillus sphaericus of the bacillus thuringiensis subsp. medellin cyt1ab1 gene results in higher susceptibility of resistant mosquito larva populations to b. sphaericus. | the fragment containing the gene encoding the cytolytic cyt1ab1 protein from bacillus thuringiensis subsp. medellin and its flanking sequences (i. thiery, a. delécluse, m. c. tamayo, and s. orduz, appl. environ. microbiol. 63:468-473, 1997) was introduced into bacillus sphaericus toxic strains 2362, 2297, and iab872 by electroporation with the shuttle vector pmk3. only small amounts of the protein were produced in recombinant strains 2362 and iab872. the protein was detected in these strains onl ... | 1998 | 9758818 |
| relative fitness of three organophosphate-resistant strains of culex pipiens pallens (diptera: culicidae). | effects of dipterex, temephos, and chlorpyrifos resistance on the relative fitness of culex pipiens pallens (l.) were evaluated by examining developmental and reproductive characteristics. age-specific life tables of dip-r- (dipterex), tmo-r- (temephos), and chl-r- (chlorpyrifos) resistant strains were compared with the susceptible strain to determine relative fitness based on population trend indices (i). the 3 organophosphate-resistant strains possessed reproductive and developmental disadvant ... | 1998 | 9775599 |
| hypersensitivity to chironomid larvae. | chironomid larvae (red midge larvae) are often used by aquarists as fish food. their hemoglobins can cause ige-mediated allergic diseases in exposed and unexposed people. the aim of this study was to find out the prevalence of positive skin tests to chironomids in patients suffering from rhinitis and/or bronchial asthma in ciudad real (spain). a total of 465 patients were submitted to skin prick tests with chironomids in addition to common inhalant allergens. the patients with positive skin pric ... | 1998 | 9777536 |
| variable cross-resistance to cry11b from bacillus thuringiensis subsp. jegathesan in culex quinquefasciatus (diptera: culicidae) resistant to single or multiple toxins of bacillus thuringiensis subsp. israelensis. | a novel mosquitocidal bacterium, bacillus thuringiensis subsp. jegathesan, and one of its toxins, cry11b, in a recombinant b. thuringiensis strain were evaluated for cross-resistance with strains of the mosquito culex quinquefasciatus that are resistant to single and multiple toxins of bacillus thuringiensis subsp. israelensis. the levels of cross-resistance (resistance ratios [rr]) at concentrations which caused 95% mortality (lc95) between b. thuringiensis subsp. jegathesan and the different b ... | 1998 | 9797262 |
| microsatellite primers for culex pipiens quinquefasciatus, the vector of avian malaria in hawaii. | 1998 | 9819914 | |
| effect of environmental temperature on the susceptibility of culex pipiens (diptera: culicidae) to rift valley fever virus. | studies were conducted to determine the effect of environmental temperature on the susceptibility of culex pipiens (l.) to rift valley fever (rvf) virus. larval rearing temperature (13, 17, 19, or 26 degrees c) did not affect the susceptibility of adult female cx. pipiens to infection with rvf virus. in contrast, the adult holding temperature after a viremic blood meal affected infection rates in females. significantly fewer mosquitoes contained detectable virus when they were held at cooler tem ... | 1998 | 9835680 |
| similarity in moth-fly specific larvicidal activity between two serologically unrelated bacillus thuringiensis strains. | parasporal inclusions of a bacillus thuringiensis isolate designated 92-ku-105-9 (h14/19) exhibited unusual larvicidal activity, specific for the moth-fly, telmatoscopus albipunctatus (diptera: psychodidae), similar to that of a previously reported b. thuringiensis serovar leesis (h33) strain. the lc50 value of the purified inclusions was 4.92 micrograms ml-1 for the moth-fly larvae, while no mortality was shown in the mosquitoes culex pipiens molestus and anopheles stephensi, at protein concent ... | 1998 | 9868764 |
| mosquito bite hypersensitivity. | we report a patient who experienced systemic anaphylaxis after several mosquito bites. the skin tests were positive, by prick and intradermal tests, with two species of common mosquito (aedes communis and culex pipiens) and also with red midge larvae (chironomus). specific ige against aedes communis was demonstrated. we carried out sds-page and immunoblotting with whole body extracts of aedes communis and culex pipiens and with red midge larvae. the immunoblotting results showed specific ige aga ... | 1998 | 9885733 |
| lethal effect of rickettsia rickettsii on its tick vector (dermacentor andersoni). | rickettsia rickettsii, the causative agent of rocky mountain spotted fever, was lethal for the majority of experimentally and transovarially infected rocky mountain wood ticks (dermacentor andersoni). overall, 94.1% of nymphs infected as larvae by feeding on rickettsemic guinea pigs died during the molt into adults and 88. 3% of adult female ticks infected as nymphs died prior to feeding. in contrast, only 2.8% of uninfected larvae failed to develop into adults over two generations. infected fem ... | 1999 | 9925615 |
| comparative linkage maps for the mosquitoes (culex pipiens and aedes aegypti) based on common rflp loci. | we report construction of a comparative linkage map for the mosquito (culex pipiens) based on restriction fragment length polymorphisms (rflps) using cdna clones from aedes aegypti as probes to southern blots of cx. pipiens genomic dna. seventy-one cdna clones were screened for hybridization and genetic diversity among three cx. pipiens strains. fifty-two of 71 cdna clones, isolated from and previously mapped in ae. aegypti (73.2%), were hybridized under high-stringency conditions with cx. pipie ... | 1999 | 9987925 |
| an overview of the evolution of overproduced esterases in the mosquito culex pipiens. | insecticide resistance genes have developed in a wide variety of insects in response to heavy chemical application. few of these examples of adaptation in response to rapid environmental change have been studied both at the population level and at the gene level. one of these is the evolution of the overproduced esterases that are involved in resistance to organophosphate insecticides in the mosquito culex pipiens. at the gene level, two genetic mechanisms are involved in esterase overproduction ... | 1998 | 10021771 |
| histopathological effects of tannic acid on the midgut epithelium of some aquatic diptera larvae. | the impact of tannins on larval nematocera was investigated by an extensive survey of the relative toxicity of tannic acid in diptera larvae representative of mosquito communities from alpine hydrosystems (culicidae, chaoboridae, chironomidae, and simuliidae) together with a nonindigenous vector competent culicidae species. bioassays indicate that exposure to tannic acid at concentrations from 0.25 to 4 mm is deleterious for culex pipiens, simulium variegatum, and chironomus annularius, but not ... | 1999 | 10066397 |
| interruption of chemical mosquito control and evolution of insecticide resistance genes in culex pipiens (diptera: culicidae). | within the llobregat delta (barcelona, spain), culex pipiens l. has been the target of organophosphate insecticide (op) control for 10 yr (1982-1992). between 1991 and 1992, ops were replaced by bacillus-based toxins in all the mosquito control programs within > 150 km of this area. the distribution of several op-resistance genes was surveyed within the llobregat delta and neighboring populations (< 25 km) during the 2 yr following this regional pesticide change to investigate how the change in ... | 1999 | 10071491 |
| mosquito feeding modulates th1 and th2 cytokines in flavivirus susceptible mice: an effect mimicked by injection of sialokinins, but not demonstrated in flavivirus resistant mice. | culex pipiens and aedes aegypti mosquitoes were fed on c3h/hej mice and systemic cytokine production was quantified from stimulated lymphocytes harvested four to ten days after feeding. mosquito feeding on c3h/hej mice significantly down regulated ifn gamma production seven to ten days post feeding by cx. pipiens and seven days after ae aegypti feeding. th2 cytokines, il-4 and il-10, were significantly up regulated 4-7 days after cx. pipiens and ae. aegypti feeding. the immunosuppressive effect ... | 1999 | 10081770 |
| the acetylcholinesterase gene ace: a diagnostic marker for the pipiens and quinquefasciatus forms of the culex pipiens complex. | the taxonomy of the culex pipiens complex remains a controversial issue in mosquito systematics. based on morphologic characters, 2 allopatric taxa are recognized, namely cx. pipiens (including the form "molestus") in temperate areas and cx. quinquefasciatus in tropical areas. here we report on variability at the nucleotide level of an acetylcholinesterase gene in several strains and natural populations of this species complex. few polymorphisms were found in coding regions within a subspecies b ... | 1998 | 10084132 |
| isolation and characterization of two novel organophosphate resistance mechanisms in culex pipiens from cyprus. | two novel mechanisms of organophosphate resistance were isolated and characterized from a population of culex pipiens l. from cyprus. two strains, one expressing the novel, highly active esterases a5 and b5 (strain a5b5-r), and one expressing insensitive acetylcholinesterase (strain ace-r), were developed by single pair crosses and selection with temephos and propoxur, respectively. the a5b5-r strain demonstrated resistance toward organophosphate insecticides that could be suppressed by the este ... | 1998 | 10084133 |
| aberrant south african mosquitoes (diptera: culicidae): gynandromorphs and morphologic variants. | two polar gynandromorphs are described, one of culex (culex) neavei theobald and the other of culex (culex) pipiens. these are the first gynandromorphs of these 2 species collected in south africa. a single variant of aedes (stegomyia) metallicus and 16 variants of aedes (stegomyia) ledgeri are also described, all of which have variation in scutal morphology. | 1998 | 10084144 |
| bacterial control of mosquito larvae: investigation of stability of bacillus thuringiensis var. israelensis and bacillus sphaericus standard powders. | bacillus thuringiensis var. israelensis and bacillus sphaericus products were assayed against their respective reference powders ips82 and sph88. since their production in 1982 and 1988, the potency and larvicidal activity of these standard powders have been regularly checked on their test insects aedes aegypti (for ips82) or culex pipiens (for sph88). over the 16-year evaluation period of ips82 and 10-year evaluation period of sph88, their potencies were considered stable. the global mean of ea ... | 1998 | 10084145 |
| culex pipiens in london underground tunnels: differentiation between surface and subterranean populations. | genetic variation was quantified between surface-dwelling populations of culex pipiens and the so-called molestus form found in the london underground (the underground) railway system. the molestus form is a commercially important biting nuisance and in the southern part of its range is also a disease vector. the surface and subterranean populations were genetically distinct, with no evidence of gene flow between closely adjacent populations of the different forms, whereas there was little diffe ... | 1999 | 10200079 |
| a new esterase gene amplification involved in op resistance in culex pipiens mosquitoes from china. | two overproduced esterases (a8 and b8) not previously described were found in southern china. they provide a low resistance level to organophosphate (op) insecticides, and correspond to a coamplification of both esterase loci (est-2 and est-3) classically involved in op resistance for this mosquito species. this coamplification is distinct from all other similar events thus far reported. the peculiar situation in southern china, where numerous op resistance alleles at these two loci were found, ... | 1998 | 10230522 |
| use of base excision sequence scanning for detection of genetic variations in st. louis encephalitis virus isolates. | twenty-two isolates of st. louis encephalitis (sle) virus of various geographical origins (brazil, argentina, panama, texas, missouri, maryland, california, and florida) were examined for genetic variation by the base excision sequence scanning (bess t-scan) method. a fragment was amplified in the envelope gene with the forward primer labeled in the pcr. the bess t-scan method determined different clusters according to the profiles generated for the isolates and successfully grouped the isolates ... | 1999 | 10325350 |
| juvenile hormone biosynthesis in diapausing and nondiapausing culex pipiens (diptera: culicidae). | the synthesis of juvenile hormone in vitro by diapausing and nondiapausing culex pipiens l. was measured by radiochemical assay. paired corpora allata from diapausing females synthesized < 18 fmols of juvenile hormone per hour during the first 3 wk after emergence. in contrast, juvenile hormone synthesis in nondiapausing females increased rapidly reaching a peak of 87.3 +/- 21 (mean +/- se) fmol/h 3 d after emergence. by 3 wk, juvenile hormone synthesis had decreased in both groups of females, b ... | 1999 | 10337107 |
| resistance to deltamethrin in culex pipiens pallens (diptera: culicidae) from zhejiang, china. | resistance to deltamethrin, a pyrethroid insecticide, was found in 7 culex pipiens pallens l. populations collected in zhejiang (southeast china). larval populations exhibited resistance ratios of 5.9-24.73 at lc50 and of 95.8-294.5 at lc95. mortality ratios between field-collected adults and susceptible laboratory adults exposed to the discriminating dosage (0.01%/20 min) were 44.7-87.3. resistance levels varied among populations as follows: wenzhou > ningbo > hangzhou > zhoushan > jiaxing > ji ... | 1999 | 10337113 |
| comparative effectiveness of three adult mosquito sampling methods in habitats representative of four different biomes of california. | the effectiveness of new jersey (nj) light, dry ice baited, and gravid female traps for collecting adult mosquitoes was compared at representative habitats in the coachella, san joaquin, and sacramento valleys and the los angeles basin of california. the nj light traps effectively sampled anopheles freeborni, culex tarsalis, psorophora columbiae, and several aedes when abundance was high in rural areas with minimal competitive illumination. dry ice-baited encephalitis virus surveillance or cdc s ... | 1999 | 10342265 |
| patterns of immunoglobulin e sensitization to chironomids in exposed and unexposed subjects. | we present our study of four patients with occupational type i allergy to red midge larvae (group 1) who we compared with seven individuals also sensitized to red midge larvae but who had not apparently been exposed to them (group 2). all patients showed elevated specific ige against chironomus thummi, and positive skin prick tests (spt) and provocation tests with red midge larvae. we carried out spt with dermatophagoides pteronyssinus, acarus siro, shrimp, cockroach and common mosquito (culex p ... | 1999 | 10353100 |
| production of cry11a and cry11ba toxins in bacillus sphaericus confers toxicity towards aedes aegypti and resistant culex populations. | cry11a from bacillus thuringiensis subsp. israelensis and cry11ba from bacillus thuringiensis subsp. jegathesan were introduced, separately and in combination, into the chromosome of bacillus sphaericus 2297 by in vivo recombination. two loci on the b. sphaericus chromosome were chosen as target sites for recombination: the binary toxin locus and the gene encoding the 36-kda protease that may be responsible for the cleavage of the mtx protein. disruption of the protease gene did not increase the ... | 1999 | 10388698 |
| effects of high temperature on the emergence and survival of adult culex pipiens molestus and culex quinquefasciatus in japan. | the emergence rate and adult survival (longevity) of japanese strains of culex pipiens molestus and culex quinquefasciatus were compared at temperatures of 21, 25, and 30 degrees c. the pupation and emergence rates in both strains were higher at 21 and 25 degrees c than at 30 degrees c. the adult emergence rate, especially in females, was lower in cx. p. molestus than in cx. quinquefasciatus. longevity of females and males was lower in cx. p. molestus at 25 degrees c and above. the survival of c ... | 1999 | 10412111 |
| buoyancy and diving behavior in mosquito pupae. | mosquito pupal diving behavior has been studied mostly in aedes aegypti and in this species pupal buoyancy varies relative to several factors. the research reported herein addresses the 2 following questions. does diving behavior vary among different mosquito genera and species? how is diving behavior influenced by variation in buoyancy? depth and duration of dive, and dive pattern, were compared among ae. aegypti, culex pipiens, anopheles stephensi, aedes albopictus, and aedes triseriatus. in r ... | 1999 | 10412114 |
| serum sickness-like syndrome due to mosquito bite. | local inflammatory reactions at the site of a mosquito bite are frequent. immediate systemic reactions have occasionally been reported. the first case of a patient with relapsing episodes of a serum sickness-like syndrome following mosquito bites is reported herein. a 62-year-old patient came to the emergency room complaining of sudden malaise, chills, fever, headache, cervical lymph node enlargement, arthromyalgia, generalized purpura and leukopenia 6 h after a mosquito bite. he had experienced ... | 1999 | 10412682 |
| [the epidemiological process of west nile viral infection]. | an important number of arboviruses are known to produce clinical or subclinical infections in humans. most of these viruses are maintained in zoonotic cycles and are transmitted by mosquitoes or ticks. viruses believed to be associated with human disease are classified according to the type of vector, the main clinical sign and the geographic distribution. the arboviruses are classified in families and genera, of which togaviridae, flaviviridae and bunyaviridae are the best known. west nile viru ... | 1998 | 10422325 |
| activation process of dipteran-specific insecticidal protein produced by bacillus thuringiensis subsp. israelensis. | dipteran-specific insecticidal protein cry4a is produced as a protoxin of 130 kda in bacillus thuringiensis subsp. israelensis. here we performed the in vitro processing of cry4a and showed that the 130-kda protoxin of cry4a was processed into the two protease-resistant fragments of 20 and 45 kda through the intramolecular cleavage of a 60-kda intermediate. the processing into these two fragments was also observed in vivo. to investigate functional properties of the two fragments, gst (glutathio ... | 1999 | 10427035 |
| toxic and growth retarding effects of three plant extracts on culex pipiens larvae (diptera: culicidae). | the toxic and/or development retarding effects on culex pipiens mosquito larvae by methanol and ether extracts of azadirachta indica, rhazya stricta and syzygium aromaticum were investigated separately. all were found to show biological activity, however, the methanol extracts showed the most profound effects. r. stricta showed marked acute (2 d) and chronic (10 d) toxic effects, having an lc(50) and 95% cl of 251(209-326) and 140(110-178); 467(416-699) and 211(198-421) ppm, for the methanol and ... | 1999 | 10441777 |
| quantitative variation and selection of esterase gene amplification in culex pipiens. | although descriptions of evolutionary mechanisms are common in the literature, very few studies focus on the possible evolution of the adaptive genes themselves, i.e. their quantitative and qualitative changes. evolution of insecticide resistance in culex pipiens is a suitable model for studying such processes. in this species, organophosphorous insecticide resistance can be achieved through the overproduction of esterases that sequester the insecticide, and this overproduction can be caused by ... | 1999 | 10447707 |
| identification of the receptor for bacillus sphaericus crystal toxin in the brush border membrane of the mosquito culex pipiens (diptera: culicidae). | the binary toxin (bin) from bacillus sphaericus crystals specifically binds to soluble midgut brush border membrane proteins from culex pipiens larvae. a single 60 kda midgut membrane protein is identified as the binding protein. this protein is anchored in the mosquito midgut membrane via a glycosyl-phosphatidylinositol (gpi) anchor, and is partially released by phosphatidylinositol specific-phospholipase c (pi-plc). fractionation of soluble proteins by anion exchange chromatography indicates t ... | 1999 | 10451923 |