Avalia??o experimental do potencial anti-carrrapato de algumas forrageiras em rela??o ?s larvas infestantes de Boophilus microplus (Canestrini, 1887) (Acarina: Ixodidae)

• Autor(a) principal: Barros, Antonio Thadeu Medeiros de
• Data de Publicação: 1989
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/4083
• topic: Medicina Veterin?ria; Medicina Veterin?ria

The pasture species, Andropogon gayanus cv. Planaltina, Brachiaria brizantha cv. Marandu, Melinis minutiflora, Stylosanthes guianensis cv. Bandeirante and Stylosanthes viscosa, were investigated to evaluate experimentally their potential antitick properties against infestive larvae of Boophilus microplus. Anti-tick properties were tested with the plant in contact with larvae (experiment in pots) and the action of volatile substances, without direct contact with the plants, in laboratory conditions (test tubes in a cabinet incubator) and in the field (in plots). The pasture plants cultivated in pots were infested with 100 larvae each and mantained in a cultivation room for 20 days. Observations were made, at 2,7 and 15 days post-infestation (dpi), to investigate the activity, localization, liberty and height reached by the larvae on the plants. Collections of larvae on the plants were also made at 5,10 and 20 days to quantify their survival, liberty and localization. x x x . In the trial with test tubes, 200 larvae were mantained in each tube together with bur separated from, a sample of the secretory material obtained from the plant. The behaviour and survival of the tick larvae were investigated. In the experiment in the field 100 larvae each were contained in gauze sachets and deposited in the pasture plants. In experiment I, collections were made at 2 and 5 days, and in experiment II, at 5 and 10 days, analising the activity and survival of tick larvae. Only M. minutiflora and S. viscosa were considered to show repellent properties. These two species and B. brizantha also showed a high lethal action against S. microplus larvae, when in contact with them. S. guianensis showed a moderated lethal effect bur A. gayanus did not show any anti-tick property. The principal lethal mechanism occurred by physical retention of the larvae by the glandular trichomes of the secretory plants. B. brizantha was specially notable due to high ability to trap larvae and absence of repellence. Various methods for the separation of infestive tick larvae into small groups for experimentation were tested, and that of larval counts with the help of a eletric suction pump was chosen as the most accurate and practical.