Tesis Medicina Veterinaria

Permanent URI for this collectionhttp://repositorio.uta.edu.ec/handle/123456789/36415

Browse

Subject: search.filters.subject.Beauveria bassiana

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Efecto in vitro de Beauveria bassiana en el control de Melophagus ovinus (Diptera: Hippoboscidae)
    (2024-08) Córdova Córdova, Johanna Lissette; López Villacis, Isabel Cristina
    Melophagus ovinus is an ectoparasite of sheep able to cause weight loss, anemia, and reduced wool growth, leading to an economic impact due to reduced production of meat, milk, and wool from sheep, as well as damage caused by the transmission of zoonotic pathogens, thus requiring permanent control measures. In this research, in vitro effect of Beauveria bassiana on the control of Melophagus ovinus was evaluated. For this purpose, the effect of four doses of the biopesticide (T1 = 1.0x105 spores/ml; T2 = 1.0x106 spores/ml; T3 = 1.0x107 spores/ml; T4 = 1.0x108 spores/ml, and distilled water was used as control) was tested on the mortality rate of adult female M. ovinus. Additionally, LD50 was calculated using Probit analysis. Concentrations of B. bassiana affected the mortality rate in M. ovinus. In general, the mortality rate was dependent on the concentration of B. bassiana, reaching 55.56% at 120 hours after applying the highest dose, which was 50% higher than the mortality observed with the lowest dose and 90% higher than the control treatment. A similar trend was observed in the second and third evaluations. Probit analysis showed an LD50 value of 1.47x105 conidia/ml, while the LD90 and LD95 values were 6.7x106 and 3.8x107 conidia/ml, respectively, which it would be expected to result in 90% and 95% mortality of the study population under in vitro conditions. According to the results, topic application of B. bassiana suspensions could be a potential alternative for controlling M. ovinus; however, in vivo evaluations are required to determine its effect on sheep.
  • No Thumbnail Available
    Item
    Prevalencia de ectoparásitos artrópodos de cuyes (Cavia porcellus) y su control con Beauveria bassiana en condiciones de laboratorio
    (2024-08) Altamirano Cevallos, Daniela Dessire; Vásquez Freytez, Carlos Luis
    Production of guinea pig (Cavia porcellus) can be affected by different factors, including skin problems, especially ectoparasites, which also predispose to secondary infections. Given the high incidence of ectoparasites, constant control measures are required, which are generally done through the use of chemical products. Therefore, in this research, the prevalence of ectoparasitic arthropods in guinea pigs in the Cevallos municipality and their control with Beauveria bassiana in laboratory conditions were evaluated. Firstly, samples were taken in the different localities in Cevallos (Vinces, Jesús del Gran Poder, Barrio La Amistad, Las Playas, Andignato, Tambo, San Pedro, Mirador, Santo Domingo, La Floresta, Belén, Santa Rosa and Agua Santa) to identify the ectoparasite species. The effect of different concentrations of a commercial product based on the entomopathogenic fungus (Beauvetic) was then evaluated: D1= 1x105 conidia (T1), D2= 1x106 conidia (T2), D3= 1 x107 conidia (T3) and a control treatment (D0) was used. Three species of ectoparasites associated with guinea pigs were identified in the different locations in the Cevallos canton, two species of mites of the genus Ornithonyssus (Ornithonyssus sp1 and Ornithonyssus sp2) and one species of chewing louse, Trimenopon hispidum, within the Trimenoponidae family. In general, mites showed a higher prevalence than lice in all the sampled areas. The effect of increasing the different concentrations of B. bassiana on the mortality of the two species of ectoparasitic mites was demonstrated, being greater when used at concentrations of 1x107 and 1x108 conidia/ml in both species of Ornithonyssus, which were significantly higher than in the rest of the treatments. Given the results obtained under in vitro conditions, it is suggested to evaluate its control effect with direct applications on guinea pigs in order to assess its safety for the animal.