64 research outputs found

    Efeitos do eucaliptol sobre a mosca doméstica (Diptera: Muscidae) e mosca varejeira (Diptera: Calliphoridae)

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    The effects of eucalyptol were evaluated against the house fly, Musca domestica L., and blow fly, Chrysomya megacephala (F.). The bioassay of adults, using topical application, indicated that M. domestica males were more susceptible than females, with the LD50 being 118 and 177 µg/fly, respectively. A higher LD50 of C. megacephala was obtained; 197 µg/fly for males and 221 µg/fly for females. Living flies of both species yielded a shorter life span after being treated with eucalyptol. The bioassay of larvae, using the dipping method on the third instar, showed that M. domestica was more susceptible than C. megacephala, with their LC50 being 101 and 642 µg/µl, respectively. The emergence of adults, which had been treated with eucalyptol in larvae, decreased only in M. domestica. Having the volatile property, fumigation or impregnated paper test of eucalyptol or the efficacy of repellence or attractiveness merits further investigations to enhance bio-insecticidal efficacy.Foram avaliados os efeitos do eucaliptol contra a mosca doméstica, Musca domestica L. e a mosca varejeira, Chrysomya megacephala (F.). O bioensaio de adultos, usando-se aplicação tópica, indicaram que os machos da M. domestica eram mais susceptíveis que fêmeas, com LD50 sendo 118 e 177 µg/mosca, respectivamente. Foi obtido mais alto LD50 da C. megacephala; 197 µg/mosca para machos e 221 µg/mosca para fêmeas. Moscas vivas de ambas espécies tiveram vida menor após tratamento com eucaliptol. O bioensaio de larvas, usando o "dipping method" no terceiro estágio, mostrou que M. domestica foi mais susceptível que C. megacephala com seu LD50 sendo 101 e 642 µg/µl, respectivamente. A emergência de adultos, que tinham sido tratados com eucaliptol na larva diminuiu somente na M. domestica. Tendo propriedade volátil, fumigação ou teste do papel impregnado por eucaliptol ou a eficácia de repelência ou de atração merecem investigações posteriores para aumentar a eficácia do bio-inseticida

    Morfometria e morfologia comparadas de ovos de Anopheles aconitus formas B e C à microscopia eletrônica de varredura

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    Comparative morphometric and morphological studies of eggs under scanning electron microscope (SEM) were undertaken in the three strains of two karyotypic forms of Anopheles aconitus, i.e., Form B (Chiang Mai and Phet Buri strains) and Form C (Chiang Mai and Mae Hong Son strains). Morphometric examination revealed the intraspecific variation with respect to the float width [36.77 ± 2.30 µm (Form C: Chiang Mai strain) = 38.49 ± 2.78 µm (Form B: Chiang Mai strain) = 39.06 ± 2.37 µm (Form B: Phet Buri strain) >; 32.40 ± 3.52 µm (Form C: Mae Hong Son strain)] and number of posterior tubercles on deck [2.40 ± 0.52 (Form B: Phet Buri strain) = 2.70 ± 0.82 (Form B: Chiang Mai strain) ; 32,40 ± 3,52 µm (Forma C: linhagem Mae Hong Son)] e número de tubérculos posteriores sobre a superfície livre [2,40 ± 0,52 (Forma B: linhagem Phet Buri) = 2,70 ± 0,82 (Forma B: linhagem Chiang Mai) < 3,10 ± 0,32 (Forma C: linhagem Chiang Mai) = 3,20 ± 0,42 (Forma C: linhagem Mae Hong Son)] embora a topografia de superfície dos ovos entre as três linhagens de duas formas cariotípicas tenham sido morfologicamente semelhantes

    PINEAPPLE JUICE AS AN AGENT FOR THE DIGESTION OF FISH PRIOR TO THE HARVESTING OF METACERCARIAE

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    Abstract. The efficacy of crude pineapple juice obtained from Ananus comosus in digesting fish for the harvesting of trematode metacercariae was investigated. No significant difference was found between the total number of metacercariae detected from fish (Cirrhina jullieni) digested by acid pepsin and those digested by freshly prepared pineapple juice that was kept for 15 days at a temperature of either -4 ˚C or -75 ˚C. However, fewer metacercariae were found when using juice that had been kept for more than 30 days. This study showed that freshly prepared pineapple juice kept frozen for 15 days could be used instead of commercial acid pepsin to digest fish for harvesting metacercariae, some of which could be used for further biological studies

    Proteínas das glândulas salivares do Anopheles dirus B (Diptera: Culicidae), vetor da malária humana

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    Salivary gland proteins of the human malaria vector, Anopheles dirus B were determined and analyzed. The amount of salivary gland proteins in mosquitoes aged between 3 - 10 days was approximately 1.08 &plusmn; 0.04 µg/female and 0.1 &plusmn; 0.05 µg/male. The salivary glands of both sexes displayed the same morphological organization as that of other anopheline mosquitoes. In females, apyrase accumulated in the distal regions, whereas alpha-glucosidase was found in the proximal region of the lateral lobes. This differential distribution of the analyzed enzymes reflects specialization of different regions for sugar and blood feeding. SDS-PAGE analysis revealed that at least seven major proteins were found in the female salivary glands, of which each morphological region contained different major proteins. Similar electrophoretic protein profiles were detected comparing unfed and blood-fed mosquitoes, suggesting that there is no specific protein induced by blood. Two-dimensional polyacrylamide gel analysis showed the most abundant salivary gland protein, with a molecular mass of approximately 35 kilodaltons and an isoelectric point of approximately 4.0. These results provide basic information that would lead to further study on the role of salivary proteins of An. dirus B in disease transmission and hematophagy.Proteínas das glândulas salivares do Anopheles dirus B (Diptera: Culicidae), vetor da malária humana foram determinadas e analisadas. A quantidade de proteínas das glândulas salivares em mosquitos com três a 10 dias de idade foi de aproximadamente 1,08 &plusmn; 0,04 µg/ fêmea e de 0,1 &plusmn; 0,05 µg/macho. As glândulas salivares de ambos os sexos mostraram organização morfológica semelhante à de outros mosquitos anofelinos. Em fêmeas, apirase acumula-se nas regiões distais, enquanto alfa-glucosidase foi encontrada na região proximal dos lóbulos laterais. Esta distribuição diferencial das enzimas analisadas reflete a especialização de diferentes regiões para alimentação de açucares e sangue. Análise SDS-PAGE revelou que pelo menos sete proteínas foram encontradas nas glândulas salivares de fêmeas, das quais cada região morfológica continha diferentes proteínas principais. Perfis eletroforéticos de proteínas semelhantes foram detectados comparando-se mosquitos não alimentados e alimentados por sangue, sugerindo que não existe proteína específica induzida pelo mesmo. Análise por gel poliacrilamida bi-dimensional mostrou a mais abundante proteína de glândulas salivares com aproximadamente 35 kilodaltons de massa molecular e ponto isoelétrico de aproximadamente 4,0. Estes resultados dão informações básicas que levariam a estudos adicionais sobre o papel das proteínas salivares do An. dirus B na transmissão da doença e hematofagia

    The susceptibility of Anopheles lesteri to infection with Korean strain of Plasmodium vivax

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    <p>Abstract</p> <p>Background</p> <p>Following its recent re-emergence, malaria has gained renewed attention as a serious infectious disease in Korea. Three species of the Hyrcanusgroup, <it>Anopheles lesteri, Anopheles sinensis </it>and <it>Anopheles pullus</it>, have long been suspected malaria vectors. However, opinions about their vector ability are controversial. The present study was designed with the aim of determining the susceptibility of these mosquitoes to a Korean isolate of <it>Plasmodium vivax</it>. Also, <it>An. sinensis </it>is primarily suspected to be vector of malaria in Korea, but in Thailand, the same species is described to have less medical importance. Therefore, comparative susceptibility of Thai and Korean strains of <it>An. sinensis </it>with Thai strain of <it>P. vivax </it>may be helpful to understand whether these geographically different strains exhibit differences in their susceptibility or not.</p> <p>Methods</p> <p>The comparative susceptibility of <it>An. lesteri</it>, <it>An. sinensis </it>and <it>An. pullus </it>was studied by feeding laboratory-reared mosquitoes on blood from patients carrying gametocytes from Korea and Thailand.</p> <p>Results</p> <p>In experimental feeding with Korean strain of <it>P. vivax</it>, oocysts developed in <it>An. lesteri</it>, <it>An. sinensis </it>and <it>An. pullus</it>. Salivary gland sporozoites were detected only in <it>An. lesteri </it>and <it>An. sinensis </it>but not in <it>An. pullus</it>. Large differences were found in the number of sporozoites in the salivary glands, with <it>An. lesteri </it>carrying much higher densities, up to 2,105 sporozoites in a single microscope field of 750 × 560 μM, whereas a maximum of 14 sporozoites were found in any individual salivary gland of <it>An. sinensis</it>. Similar results were obtained from a susceptibility test of two different strains of <it>An. sinensis </it>to Thai isolate of <it>P. vivax</it>, and differences in vector susceptibility according to geographical variation were not detected.</p> <p>Conclusion</p> <p>The high sporozoite rate and sporozoite loads of <it>An. lesteri </it>indicate that this species is highly susceptible to infection with <it>P. vivax</it>. <it>Anopheles sinensis </it>appears to have a markedly reduced ability to develop salivary gland infection, whilst in <it>An. pullus</it>, no sporozoites were found in the salivary glands. Provided that the survival rate of <it>An. lesteri </it>is sufficiently high in the field, it would be a highly competent vector of vivax malaria.</p

    Suscetibilidade de duas formas cariotípicas de Anopheles aconitus (Diptera: Culicidae) a Plasmodium falciparum e P. vivax

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    Four laboratory-raised colonies of two karyotypic forms of Anopheles aconitus, i.e., Form B (Chiang Mai and Phet Buri strains) and C (Chiang Mai and Mae Hong Son strains), were experimentally infected with Plasmodium falciparum and P. vivax using an artificial membrane feeding technique and dissected eight and 12 days after feeding for oocyst and sporozoite rates, respectively. The results revealed that An. aconitus Form B and C were susceptible to P. falciparum and P. vivax, i.e., Form B (Chiang Mai and Phet Buri strains/P. falciparum and P. vivax) and Form C (Chiang Mai and Mae Hong Son strains/P. vivax). Comparative statistical analyses of the oocyst rates, average number of oocysts per infected midgut and sporozoite rates among all strains of An. aconitus Form B and C to the ingroup control vectors, An. minimus A and C, exhibited mostly no significant differences, confirming the high potential vector of the two Plasmodium species. The sporozoite-like crystals found in the median lobe of the salivary glands, which could be a misleading factor in the identification of true sporozoites in salivary glands were found in both An. aconitus Form B and C.Quatro colônias desenvolvidas em laboratório, de duas formas cariotípicas de Anopheles aconitus i.e. forma B (cepa Chiang Mai e Phet Buri) e C (Cepa Chiang Mai e Mae Hong Son), foram infectadas experimentalmente com Plasmodium falciparum e P. vivax usando técnica de alimentação com membrana artificial e dissecados oito e 12 dias após alimentação da média de oocistos e esporozoitos, respectivamente. Os resultados revelaram que An. aconitus formas B e C foram suscetíveis ao P. falciparum e P. vivax isto é, forma B (cepa Chiang Mai e Phet Buri/P. falciparum e P. vivax) e forma C (cepa Chiang Mai e Mae Hong Son/P. vivax). Análises estatísticas comparativas das taxas de oocistos, número médio de oocistos por intestino médio infectado e taxas de esporozoitos entre todas as cepas de An. aconitus formas B e C ao grupo interno de vetores controles, An. minimus A e C, não exibiram nenhuma diferença significante, confirmando o alto potencial vetor das duas espécies de Plamodium. Os cristais semelhantes a esporozoitos encontrados no lobo médio das glândulas salivares que poderiam ser um fator enganoso na identificação de esporozoitos verdadeiros nas glândulas salivares foram encontrados em ambos An. aconitus formas B e C

    Evidence to Support Karyotypic Variation of the Mosquito, Anopheles peditaeniatus in Thailand

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    Eight isoline colonies of Anopheles peditaeniatus Leicester (Diptera: Culicidae) were established from wild-caught females collected from buffalo-baited traps at 8 localities in Thailand. They showed 2 types of X (X2, X3) and 4 types of Y (Y2, Y3, Y4, Y5) chromosomes based on the number and amount of major block(s) of heterochromatin present in the heterochromatic arm, and were tentatively designated as Forms B (X2, X3, Y2), C (X3, Y3), D (X3, Y4) and E (X2, X3, Y5). Form B was found in Nan, Ratchaburi, and Chumphon provinces; Form C was obtained in Chon Buri province; Form D was recovered in Kamphaeng Phet province; and Form E was acquired in Chiang Mai, Udon Thani, and Ubon Ratchathani provinces. Crossing studies among the 8 isoline colonies, which were representative of 4 karyotypic forms of An. peditaeniatus, revealed genetic compatibility in providing viable progenies and synaptic salivary gland polytene chromosomes through F2-generations, thus suggesting the conspecific nature of these karyotypic forms. These results were supported by the very low intraspecific sequence variations (0.0 – 1.1%) of the nucleotide sequences in ribosomal DNA (ITS2) and mitochondrial DNA (COI and COII) of the 4 forms

    Susceptibility of Anopheles campestris-like and Anopheles barbirostris species complexes to Plasmodium falciparum and Plasmodium vivax in Thailand

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    Nine colonies of five sibling species members of Anopheles barbirostris complexes were experimentally infected with Plasmodium falciparum and Plasmodium vivax. They were then dissected eight and 14 days after feeding for oocyst and sporozoite rates, respectively, and compared with Anopheles cracens. The results revealed that Anopheles campestris-like Forms E (Chiang Mai) and F (Udon Thani) as well as An. barbirostris species A3 and A4 were non-potential vectors for P. falciparum because 0% oocyst rates were obtained, in comparison to the 86.67-100% oocyst rates recovered from An. cracens. Likewise, An. campestris-like Forms E (Sa Kaeo) and F (Ayuttaya), as well as An. barbirostris species A4, were non-potential vectors for P. vivax because 0% sporozoite rates were obtained, in comparison to the 85.71-92.31% sporozoite rates recovered from An. cracens. An. barbirostris species A1, A2 and A3 were low potential vectors for P. vivax because 9.09%, 6.67% and 11.76% sporozoite rates were obtained, respectively, in comparison to the 85.71-92.31% sporozoite rates recovered from An. cracens. An. campestris-like Forms B and E (Chiang Mai) were high-potential vectors for P. vivax because 66.67% and 64.29% sporozoite rates were obtained, respectively, in comparison to 90% sporozoite rates recovered from An. cracens
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