ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00147.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00148.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Resistance to human body lice,Pediculus humanus humanusL, induced by feeding on rabbits immunized with an extract of louse gut was studied. The mortality of lice fed on immunized rabbits was 73%, significantly higher than that of lice fed on control rabbits (52%) (P<0.01). The proportion of dead nymphs and female lice with ruptured guts was significantly higher in lice fed on immunized rabbits (P<0.01). The size of the bloodmeal was 35% greater in female lice fed on control rabbits than on immunized rabbits. Lice fed on immunized rabbits laid 40% less eggs than those fed on the controls, they also demonstrated a significant decrease in the number of eggs per female over time (P<0.01).86% of the eggs laid by lice fed on immunized animals hatched, compared with 92% hatching of eggs laid by the lice fed on control animals (P<0.01). With the exception of the first bloodmeal the percentage of hatched eggs which were laid between any two bloodmeals was significantly smaller (p<0.01) in the lice fed on immunized rabbits than in the control group. The first nymphal stage of lice fed on immunized rabbits took an average of 5.2 days to moult to the second stage, compared with 4 days for those fed on control rabbits.

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00149.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Semiochemical components of eggs of the sandflyLutzomyia longipalpis(Diptera: Psychodidae) were separated by high performance liquid chromatography. HPLC fractions were examined quantitatively and qualitatively by gas chromatography (GC). A bioassay was used to determine the oviposition attraction of gravidL. longipalpisto each of the fractions separately and a peak responsible for the semiochemical activity was identified. Gravid flies were placed in individual oviposition tubes to determine if the peak of interest was an oviposition stimulant. The active semiochemical fraction attracted gravid flies for oviposition. Furthermore, egg laying was enhanced: gravid flies exposed to the pheromone oviposited earlier and laid more eggs than control flies. GC analysis indicated that 1200 eggs (2 days old) gave a yield of 12.75 ug of active pheromone. This fraction had similar HPLC and GC retention times to caryophyllene oxide, suggesting comparable polarity and molecular weight.

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00150.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.The nuisance activity of blackflies (Diptera: Simuliidae) was investigated in several habitats on Speyside, near Kincraig (57o08'N, 3o56'W), Invernesshire, in central Scotland during May‐October 1987‐89.The main blackfly species caught landing/biting on humans wereSimulium reptans, S. argyreatum, S. variegetumand theS. tuberosumcomplex, in order of prevalence. Blackfly biting activity occurred from mid‐May to mid‐September. Numbers of female blackflies attracted to volunteers were correlated with their body posture, habitat and the season. Overall,Simuliumactivity was greatest in mixed birch/juniper forest, least in spruce plantations and at intermediate levels on pasture, moorland and in Scots Pine forest.Compared with an adult, a child experienced twice as manySimuliumbites per hour (12.2 v 6.3) in the birch forest. On the child's body, 69% of blackfiies landed on the head, neck and back, whereas the majority landed on the legs (48%) and arms (28%) of adults. Bending over, especially during the exertion of gardening, was more attractive to anthropophilic blackfiies than standing or k

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00151.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractTwo large colonies, originating from allopatric populations ofGlossina pallidipesAusten, in the Shimba Hills and Nguruman, Kenya, which differ biologically and with respect to vectorial competence, were compared at fourteen enzyme loci using polyacrylamide gel electrophoresis. The colonies had similar levels of genetic diversity with approximately half of the loci being polymorphic, an average of 1.6‐1.7 alleles per locus, and a mean heterozygosity per locus of approximately 18.4%. However, the colonies differed significantly in allele frequencies at the loci for phosphoglucomutase, glucose‐6‐phosphate dehydrogenase, xanthine oxidase, octanol dehydrogenase and phosphoglucose isomerase. The results were compared with earlier studies on this species and no evidence was found for selection of specific alleles during establishment or maintenance of colonies ofG.pallidipes, nor were specific chromosomes, or marker genes, associated with the biological differences between the two col

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00152.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractGenetically controlled enzyme variation exists within and between four sibling species of theAnopheles culicifaciescomplex of malaria vectors in India. A study on electrophoretic variation of nine enzymes inAn.culicifaciessibling species revealed that the lactate dehydrogenase (Ldh) locus has Fast (F) and Slow (S) allozymes distinguishing species A+D from species B+C with a probability ofc. 95%.

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00153.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractProtein components of homogenates of unfed larvae and nymphs ofIxodes ricinus(L.), and of ovary, haemolymph, Malpighian tubules, rectal ampulla, fat body, integument, salivary glands and midgut of partially fed adult females were studied for their antigenicity and carbohydrate moieties using immunoblotting and lectin affinity blotting (LAB) techniques. Comparing the individual anti‐larval, anti‐nymphal and anti‐adult immune sera for their capacity to recognize the specific and trans‐stadially cross‐reactive antigenic proteins, larval feeding induced the most effective humoral response. The majority of immunogens recognized by rabbit anti‐tick immune sera are glycoproteins. Most of the glycosylated antigens were modified with N‐type glycans; however, O‐type glycans were also demonstrated in some antigens. The correlation of the type of glycosylation with antigenicity, and the sharing of common antigenic epitopes by various tissues

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00154.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractAcidic and non‐acidic fractions from extracts of fluid from sheep wounds infested with larvae ofCochliomyia hominivorax(Coquerel) were analysed by linked gas chromatography and electroantennography in order to detect electrophysiologically‐active compounds that could be potential attractants. Responses to twenty‐six electrophysiologically‐active compounds were observed and, on the basis of electron impact and chemical ionization mass spectrometry and co‐chromatography with authentic compounds, twenty‐five of these compounds were characterized. The most abundant compounds identified in the larval wound fluid were straight and methyl‐branched aliphatic carboxylic acids, ranging from C2‐ to C5‐carbon chain length. Butanoic acid, for example, was found to be present at approximately 0.45mg/ml. Aliphatic carboxylic acids with longer chain lengths were also observed but in trace amounts. Three aromatic carboxylic acids, benzoic, phenylethanoic and 3‐phenylpropanoic acids were also present but only phenylethanoic and 3‐phenylpropanoic acids elicited electroantennographic responses. Phenol and indole were by far the most abundant components of the non‐acid fraction of the larval wound fluid with all other components, except δ‐valerolactam, present at levels of less than 5% that of phenol which was present at a concentration of 0.05 mg/ml.Electroantennographic studies of straight‐chain aliphatic carboxylic acids showed that pentanoic acid elicited the strongest response fromC. hominivorax.Similar studies showed that 1‐octen‐3‐ol elicited stronger responses than 3‐methylphenol, indole, phenol or dimethyldisulphide. 3‐Methylindole, which was not found in the wound fluid, also elicited a strong response.The potential behavioural significance of these compounds is discussed in relation to that of known attractants ofC. hominivo

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00155.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Abstract.Field trials were undertaken to determine the effect of close proximity of humans to livestock on the human biting rates exhibited by various anophelines. The results indicate that proximity to cattle and to goats increases the subject's chances of being bitten by anophelines. Man‐biting byAnopheles stephensirose by 38% (8–68% CI) in the presence of a cow, and by 50% (16–84% CI) in the presence of two goats. Other species exhibited similar trends. These findings explain the results of an earlier trial which revealed that malaria prevalence was higher amongst families that kept cattle than those that did not.The findings are discussed in relation to existing information regarding the host preferences of local anophelines and classic theories regarding zooprophylaxis. Our findings suggest that animals are only likely to have a worthwhile prophylactic affect when the vector is zoophilic, and then only when the animals are deployed to form a barrier between that vector and man. In situations where deployment of livestock to form a zoobarrier is impractical, the livestock should be located as far from man as pos

ISSN:0269-283X    

DOI:10.1111/j.1365-2915.1994.tb00156.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY