Life cycle of the tick Amblyomma parvum Aragão, 1908 (Acari: Ixodidae) and suitability of domestic hosts under laboratory conditions.

Amblyomma parvum is a widespread Neotropical tick found on several domestic animals and is known to harbor a Rickettsia species of yet unknown pathogenicity. However its life cycle on, and suitability of, several of these hosts has not been described. In this work the biology of A. parvum is presented when fed on seven domestic hosts (chicken, dog, rabbit, horse, guinea pig, cattle and goat). The complete life cycle of the tick varied from 96.8 to 102 days. Highest engorgement weight of larvae was from ticks fed on horses and that of nymphs from guinea pigs. Highest larval yield was from guinea pigs and that of nymphs from horses. Engorged female and egg mass weights, yield and conversion of female weight to eggs rates were the highest in dog ticks and the lowest in goat ticks. The highest egg hatching rate was seen in ticks from dogs and the lowest in ticks from cattle. Overall it was seen that dogs were the best host for adult A. parvum ticks, and guinea pigs for immatures. Horses were also shown to be a good host for all tick stages. It can thus be affirmed that A. parvum is a host generalist tick, and its distribution is probably determined by environmental requirements rather than by hosts.

Ticks (Acari: Ixodidae) on dogs from Uberlândia, Minas Gerais, Brazil.

Uberlândia in Minas Gerais State, southeastern Brazil, has 622 000 inhabitants and is located in the Cerrado biome, the South American savannah. The city dog population is estimated at 82 000 and identification of tick species and infestation prevalence on this host has not been determined. A major infectious disease of dogs in the city, canine ehrlichiosis, is transmitted by Rhipicephalus sanguineus ticks. At the same time, autochthonous leishmaniosis has been recently described in the city and a role for dog ticks in the disease transmission has been supposed in Brazil. In this work, we present general information on dog ticks in Uberlândia municipality and region. Dogs from 33 farms and 31 districts were examined for ticks from July 2007 to February 2009. On the whole, 413 dogs were examined, 311 (75.3%) from the city and 102 (24.6%) from rural area. Overall infestation rate of dogs from Uberlândia was 37.3% and the mean infestation intensity was 3.25 parasites per dog. In the urban area, 100 dogs (32.2%) had ticks whereas 54 dogs (52.9%) from rural areas were infested. Four tick species were found: Rhipicephalus sanguineus, Amblyomma cajennense, Amblyomma ovale and Boophilus microplus. In the city, only R. sanguineus and one A. cajennense was found on dogs and R. sanguineus and A. ovale were the main dog ticks in rural areas.