scholarly journals Arthropod transmission of rabbit fibromatosis (Shope)

1959 ◽  
Vol 57 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Herbert T. Dalmat
Keyword(s):  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Rhodnius Prolixus ◽  
Triatoma Infestans ◽  
Cimex Lectularius ◽  
Virus Titre ◽  
Virus Suspension ◽  
Anopheles Quadrimaculatus ◽  
Domestic Rabbits ◽  
Reduviid Bugs

The mosquitoes Aedes aegypti, A. triseriatus, Culex pipiens, C. quinquefasciatus, and Anopheles quadrimaculatus were all found to be efficient experimental vectors of Shope's virus-induced fibromas of cottontail rabbits, transmitting the virus during interrupted feedings as well as after long intervals from an infective meal. The reduviid bugs, Triatoma infestans, T. phyllosoma pallidipennis and Rhodnius prolixus, and the bedbug, Cimex lectularius, were also capable of transmitting fibroma by interrupted or delayed feeding.Evidence from various types of experiments indicated that arthropod transmission is mechanical, the virus being extremely stable in the insects. Some experiments did indicate the possibility of virus proliferation. Although mosquitoes did seem to serve as ‘flying pins’ when transmitting virus by interrupted feeding, they certainly were distinctive in that they maintained their ability to transmit for very long periods of time. To transmit fibromas, arthropods actually must draw virus up between the stylets of the mouthparts; mosquitoes were unable to transmit by feeding through skin moistened with a suspension of fibroma virus or by feeding subsequent to having their mouthparts painted with a virus suspension.While cottontail tumours at peak virus titres are always infective for suitable insects, the fibromas of adult domestic rabbits generally are not infective, even though the virus titre is equivalent. However, the tumours of suckling domestic rabbits do become infective for insects.

scholarly journals ARTHROPOD TRANSMISSION OF RABBIT PAPILLOMATOSIS

1958 ◽  
Vol 108 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Herbert T. Dalmat
Keyword(s):  
Aedes Aegypti ◽  
Malignant Transformation ◽  
Rhodnius Prolixus ◽  
Triatoma Infestans ◽  
Neoplastic Disease ◽  
Subcutaneous Nodules ◽  
Insect Transmission ◽  
Domestic Rabbits

The virus of rabbit papillomatosis, a neoplastic disease studied intensively in relation to cancer because of its tendency toward malignant transformation, has been successfully transmitted by Aedes aegypti, Rhodnius prolixus, and Triatoma infestans from papillomas induced in cottontail rabbits, and by the first species mentioned, from papillomas induced in domestic rabbits. This was accomplished by interrupted feeding, feeding after an interval of several days from the infective meal, or by application of a suspension of the mouthparts of the insects either immediately after their infective meal or several days later. Insect transmission was also successful from the satellite growths resulting from subcutaneous extensions of the typical papillomas of infected cottontails, and from certain peculiar, subcutaneous nodules, arising rapidly after infection, and not heretofore described. Although the latter growths resembled rabbit fibromas, antibodies to fibroma virus could not be demonstrated by neutralization tests with the sera of the animals involved.

Estudio y evaluación de depredadores y bacterias entomopatógenas de Aedes aegypti (L.) y Culex pipiens (L.), como potenciales agentes de control

2010 ◽  
Author(s):  
◽  
María Cecilia Tranchida
Keyword(s):  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Principal Vector ◽  
La Plata

Aedes aegypti y Culex pipiens se encuentran entre las principales especies de mosquitos vectores de enfermedades a nivel mundial. Ambas, son de gran importancia sanitaria en la Argentina. Aedes aegypti, es el principal vector del dengue y la fiebre amarilla. Está presente en la Argentina desde 1983, cuando fue confirmada su reemergencia en nuestro país. A partir de entonces comenzaron a detectarse casos de dengue hasta que el último brote de esta enfermedad en 2009 produjo 24.720 casos autóctonos confirmados por la OPS a nivel nacional. Culex pipiens es vector de algunas filariasis, y de importantes arbovirosis como la ocasionada por el virus del Nilo Occidental. La actividad vectorial de este mosquito se ve incrementada en zonas donde la densidad de zanjas de desagüe domiciliario es elevada, ya que este tipo de ambiente constituye un lugar propicio para su desarrollo. De su importancia sanitaria nace la necesidad de controlar su actividad vectorial, manteniendo las poblaciones en bajas densidades. El objetivo de este trabajo fue desarrollar estrategias para el control de A. aegypti y C. pipiens, basadas en métodos biológicos, eficaces, permanentes y seguros para el ambiente, mediante el empleo de enemigos naturales presentes en las poblaciones de ambas especies. En este trabajo, fueron evaluados copépodos, turbelarios y peces como depredadores; y bacterias entomopatógenas (α-protobacterias y bacterias esporulantes). El estudio de los copépodos, tuvo como objetivo identificar a la comunidad de copépodos larvívoros que se desarrolla en los criaderos de mosquitos, ubicados en los alrededores de la ciudad de La Plata, para identificar nuevas especies capaces de depredar mosquitos que habitan recipientes artificiales (A. aegypti y C. pipiens). La diversidad de copépodos larvívoros fue mayor en los cuerpos de agua permanentes. Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus fueron seleccionados por su capacidad depredadora. En el laboratorio fueron evaluadas: la capacidad de depredación de ambos sexos y diferentes estadios, preferencia de especie presa, y la tasa de depredación diaria. Las hembras de estas especies de copépodos presentaron mayor capacidad depredadora. No se detectó preferencia de los copépodos hacia ninguna de las especies de mosquitos. También se evaluó la tolerancia a la desecación y la capacidad de vivir en el agua que se acumula en los recipientes artificiales. Diacyclops uruguayensis y A. robustus sobrevivieron en las condiciones de sequía ensayadas en este estudio, pero D. uruguayensis mostró una menor supervivencia en el agua de recipientes artificiales. Macrocyclops albidus no sobrevivió en condiciones de sequía ni toleró el agua extraída de los recipientes artificiales. La supervivencia de M. longisetus ante estas condiciones, fue reducida. Se concluyó que las especies D. uruguayensis y A. robustus podrían ser buenos candidatos para el control de especies de mosquitos que crían en recipientes artificiales.

scholarly journals Cloning and Expression of Two Crystal Protein Genes, cry30Ba1 and cry44Aa1, Obtained from a Highly Mosquitocidal Strain, Bacillus thuringiensis subsp. entomocidus INA288

2006 ◽  
Vol 72 (8) ◽  
pp. 5673-5676 ◽  
Author(s):  
Takeshi Ito ◽  
Tomonori Ikeya ◽  
Ken Sahara ◽  
Hisanori Bando ◽  
Shin-ichiro Asano
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Crystal Protein ◽  
Cloning And Expression ◽  
Culex Pipiens Pallens ◽  
Bacillus Thuringiensis Subsp ◽  
Pipiens Pallens ◽  
Crystal Protein Genes

ABSTRACT Two novel crystal protein genes, cry30Ba and cry44Aa, were cloned from Bacillus thuringiensis subsp. entomocidus INA288 and expressed in an acrystalliferous strain. Cry44Aa crystals were highly toxic to second-instar Culex pipiens pallens (50% mortality concentration [LC50] = 6 ng/ml) and Aedes aegypti (LC50 = 12 ng/ml); however, Cry30Ba crystals were not toxic.

The Susceptibility of various Species of Mosquitos to DDT, Dieldrin and BHC

1955 ◽  
Vol 46 (2) ◽  
pp. 301-309 ◽  
Author(s):  
R. H. Wharton
Keyword(s):  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Lethal Concentration ◽  
Median Lethal Concentration ◽  
Adult Females ◽  
Anopheles Maculipennis ◽  
Culex Pipiens Molestus ◽  
Filter Papers

The susceptibility of various mosquitos to DDT, dieldrin and BHC has been studied. Adult females were exposed in small tubes lined with filter papers impregnated with insecticide-oil solutions. Larvae were exposed to insecticideacetone suspensions in water.Adult mosquitos tested in London showed no striking differences in susceptibility to DDT, though the median lethal concentration (MLC) of Culex pipiens molestus Forsk. (1·6 per cent.) was greater than the MLC of Aëdes aegypti (L.) (0·9), Anopheles maculipennis var. atroparvusvan Thiel (1·0), or A. quadrimaculatus Say (·7). C. p. molestus and Aë. aegypti showed the same order of susceptibility to dieldrin and BHC, with Anopheles m. atroparvus more susceptible to both insecticides.

scholarly journals Situação do controle da transmissão vetorial da doença de Chagas nas Américas

2000 ◽  
Vol 16 (suppl 2) ◽  
pp. S35-S42 ◽  
Author(s):  
Antonio Carlos Silveira
Keyword(s):  
Rhodnius Prolixus ◽  
Triatoma Infestans

Este trabalho identifica e descreve distintas situações do ponto de vista epidemiológico em relação à transmissão natural da doença de Chagas no continente. A importância relativa das principais espécies de vetor na veiculação da doença e o nível de controle que se pode pretender em cada caso são examinados. Apresentam-se as estimativas existentes no que concerne à população sob risco, bem como ao número de casos de infecção e de doença crônica. Por fim discutem-se as perspectivas do controle, com base nos resultados obtidos e que podem ser colhidos com a introdução de espécies como Triatoma infestans, no Cone Sul, e Rhodnius prolixus, em parte da América Central e com as demais espécies, autóctones das áreas onde são encontradas. Além disso, questiona-se o papel que os demais mecanismos de transmissão poderão representar na manutenção da endemia chagásica.

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