Host specificity of Amblyomma cajennense (Fabricius, 1787) (Acari: Ixodidae) with comments on the drop-off rhythm

The parasitic specificity of larval, nymph and adult Amblyomma cajennense on six different host species: Oryctolagus cuniculus, Rattus norvegicus, Gallus gallus domesticus, Anas platyrhynchus, Coturnix coturnix and Streptopelia decorata is described. In terms of the numbers of larvae and nymphs recovered, O. cuniculus was the best host species. The modal day for drop-off of lavae and nymphs was day three for the mammal hosts, but variable in the birds. We conclude that adult A. cajennense have a strong degree of specificity due to the fact that the tick failed to complete its cycle on any of the evaluated hosts. The immature stages, on the other hand, showed a low level of specificity, most specially in the larval stage, indicating the existence of secondary hosts which probably serve as dispersers in the wild. The results also indicated a variable drop-off rhythm for larvae and numphs in two periods, diurnal (6-18 hr) and nocturnal (18-6 hr), which differed depending upon the host.

Study of the weight of eggs from six ixodid species from Brazil

Eggs from engorged females of six ixodidae species (Ixodes Iocatus, Amblyomma rotundatum, A. cajennense, Haemaphysalis leporis-palustris, Boophilus microplus, Dermacentor nitens) maintained in laboratory were counted to calculate the number and mean weight in Ig of eggs from each species. Phylogenetic considerations are discussed based on the results.