Comparing feeding and reproductive parameters of Amblyomma parvum tick populations (Acari: Ixodidae) from Brazil and Argentina on various host species

Abstract

Amblyomma parvum is a Neotropical tick that is widely spread and a potential vector of pathogens, including Rickettsiae. Genetic differences are remarkable between A. parvum populations from Brazil and Argentina. In this work, feeding and reproduction parameters of A. parvum ticks from these two populations were compared on some key host species to evaluate possible differences in host suitability between them. On the whole parameters of these tick populations were similar when fed on the same host and varied similarly on different host species. Still, bovines were more suitable host for Argentinian larvae than for Brazilian cohorts. It was observed that guinea pigs were the best host A. parvum immatures from both origins, as depicted from higher recovery rate of larvae and heavier engorged nymph weights. Canids and bovids were host species most suitable to adults of both tick populations as shown by the highest number of larvae produced by adult females that engorged on these hosts. Taken together, results showed that in spite of the genetic divergence, A. parvum from Argentina and Brazil have similar biological performance on various host species.

Amblyomma nodosum (Neumann, 1899): observations on life cycle under laboratory conditions

“…As for the immature stages of A. nodosum, it was possible to recover more than 50% of the specimens, which is comparable to the range of recovery of other Neotropical species of Amblyomma raised in the laboratory under similar conditions (SANAVRIA & PRATA, 1996;LABRUNA et al, 2002aLABRUNA et al, , 2004PINTER et al, 2004;FACCINI et al, 2010;MARTINS et al, 2012;GERARDI et al, 2013). The immature stages of A. nodosum parasitize several species of birds, showing low specificity (LABRUNA et al, 2007;OGRZEWALSKA et al, 2009, LUZ et al, 2012PASCOAL et al, 2013;TORGA et al, 2013;NAVA & GUGLIELMONE, 2013).…”

Amblyomma parvum Aragão, 1908 (Acari: Ixodidae): Phylogeography and systematic considerations

“…Multiple sources of morphological, molecular, and biological evidence should be combined in order to reliably delimit species. When Gerardi et al (2013) compared feeding and reproductive parameters of A. parvum colonies from Argentina and Brazil infesting different host species, they could not reveal any significant difference between ticks from the two countries.…”

Different lines of evidence used to delimit species in ticks: A study of the South American populations of Amblyomma parvum (Acari: Ixodidae)

“…Therefore, although the gene flow between the two populations might still be limited due to geographic distance, the absence of reproductive barriers and the lack of significant morphological differences suggest that populations of A. parvum from Argentina and Brazil should be treated as a single species. Further evidence supporting this conclusion is provided by the absence of significant differences in the niche preferences between A. parvum from Argentina and Brazil, and also by the study of Gerardi et al (2013), where A. parvum from Argentina and Brazil showed similar biological performances when they were fed on different mammal hosts, namely Guinea pigs, rabbits, dogs and cattle. In the light of the results presented in this work, values of genetic divergence between 3% and 4% in sequences of the mitochondrial 16S rRNA gene of Amblyomma ticks should not be considered as conclusive evidence on the taxonomic status at the species level within this tick genus.…”