EFFICACY OF NEEM (Azadirachta indica) IN THE CONTROL OF Amblyomma cajennense (FABRICIUS, 1787) (ACARI: IXODIDAE) LARVAE AND NYMPHS

Fernandes J.I., Correia T.R., Ribeiro F.A., Cid Y.P. & Scott F.B. [Efficacy of neem (Azadirachta indica) in the control of Amblyomma cajennense (Fabricius, 1787) (Acari: Ixodidae) larvae and nymphs.] Eficacia do nim (Azadirachta indica) no controle de larvas e nifas de Amblyomma cajennense (Fabricius, 1787) (Acari: Ixodidae). Revista Brasileira de Medicina Veterinciria, 32(Supl. 1):50-54, 2010. Faculdade de Medicina Veterinaria, Universidade Federal do Para, Avenida Universitaria, s/n, Pirapora, Campus de Castanhal, PA 68750-000, Brasil. E-mail: fernandesji@ufpa.br Ixodid ticks are ectoparasites which infest both domestic and wild animals, causing impact to animal husbandry. Amblyomma cajennense is one of the ixodids with lower parasitic specificity, and can cause various diseases to man, including Rickettsia rickettsii, etiological agent of the spotted fever. Recently, the control of this parasite has been realized by using chemical compounds, which are, in general, toxic to the animals, the environment and human beings. The objective of the present study was to evaluate the efficacy of different concentrations of a 10% neem aqueous extract on the control of A. cajennense larvae and nymphs using an in vivo assay. The number of engorged larvae recovered from the control group was lower than the number from treated group, demonstrating inefficacy in repelling ticks. However, treated larvae suffered alterations on ecdysis. The efficacy level calculated from the number of infested larvae and number of recovered nymphs was 27.91%. No difference was observed between, nymphs from control and treated groups. Even leading to alterations on larval ecdysis, the 10% neem aqueous extract was inefficacious on the control of A. cajennense larvae and nymphs.