Biological parameters of cattle ticks fed on rabbits / Parâmetros biológicos de carrapatos bovinos alimentados em coelhos

With the objective of encouraging the use of rabbits as alternative hosts for the cattle tick, four rabbits were infested on the ears and back. From the second day of infestation the developmental stages were observed. e duration of larval engorgement and changes were estimated between six and eight days in the region of the back and between 've and seven days in the pinna. e nymphal engorgement and changes occurred at approximately 10.80 ± 2.65 days in the dorsal and 11.00 ± 2.52 days in the ear, with the engorgement of adults and copulation occurring at 7.03 ± 2.45 days, on the dorsal region and 8.55 ± 1.82 days in the region of the pinna. e parasitic period ranged from 21 to 29 days (back) and from 23 to 30 days (pinna). e engorged females of the back and ear weighed on average 34.43 ± 18.73 and 36.30 ± 18.10 mg, respectively. e nutritional and reproductive e/ciency indexes were 17.38 ± 14.27 and 26.85 ± 17.13% (back) and 17.42 ± 12.22% and 30.70 ± 19.80% (pinna). Although not appropriate to maintain successive generations of Rhipicephalus (Boophilus) microplus, rabbits can be used for di:erent stages of engorgement of the ixodid, allowing experimental studies.

Com objetivo de viabilizar o uso de coelhos como hospedeiros alternativos do carrapato bovino, foram infestados quatro coelhos nas orelhas e no dorso. A partir do segundo dia da infestação, foram observados os estágios de desenvolvimento dos carrapatos. A duração do ingurgitamento e muda larval foi estimada entre seis e oito dias na região do dorso e entre cinco e sete dias no pavilhão auricular. O ingurgitamento e muda ninfal ocorreram em aproximadamente, 10,80 ± 2,65 dias na região dorsal e 11,00 ± 2,52 dias no pavilhão auricular; e o ingurgitamento e cópula dos adultos ocorreu em 7,03 ± 2,45 dias, na região do dorso e em 8,55 ± 1,82 dias na região do pavilhão auricular . O período parasitário variou de 21 a 29 dias (dorso) e de 23 a 30 dias (pavilhão auricular). As fêmeas ingurgitadas do dorso e orelha pesaram, em média, 34,43 ± 18,73 e 36,30 ± 18,10 mg, respectivamente. Os índices de e'ciência reprodutiva e nutricional foram de 17,38 ± 14,27 e 26,85 ± 17,13% (região do dorso) e de 17,42 ± 12,22% e 30,70 ± 19,80% (pavilhão auricular). Embora não sejam adequados para manter sucessivas gerações de Rhipicephalus (Boophilus) microplus, os coelhos podem ser empregados para o ingurgitamento dos diferentes estádios deste ixodídeo, viabilizando estudos experimentais.

Ticks on domestic animals in Pernambuco, Northeastern Brazil / Carrapatos em animais domésticos em Pernambuco, Nordeste do Brasil

The objective of this article was to discuss some aspects of ticks associated with domestic animals in the State of Pernambuco, northeastern Brazil, based on a literature review and present new data obtained from recent tick collections carried out in this northeastern Brazilian state. From August 2007 to June 2008, 1,405 ticks were collected and five species were identified: Amblyomma cajennense (Fabricius, 1787), Amblyomma ovale Koch, 1844, Dermacentornitens Neumann, 1897, Rhipicephalus (Boophilus) microplus (Canestrini, 1887), and Rhipicephalus sanguineus (Latreille,1806). Dogs from urban areas were found exclusively infested by R. sanguineus, whereas dogs from rural areas were found infested by A. cajennense, A. ovale, R. (B.) microplus, and R. sanguineus. The only tick species found on cattle and goats was R. (B.) microplus. Horses were found infested by D. nitens and at a lesser extent by A. cajennense and R. (B.) microplus. The only tick species found on donkeys was D. nitens. This study confirms the presence of A. cajennense inPernambuco and describes for the first time the presence of A. ovale in this state. The medical and veterinary relevance and control of ticks associated with domestic animals in Pernambuco are also briefly discussed.

O objetivo desse artigo é discutir alguns aspectos relacionados aos carrapatos que parasitam animais domésticos no Estado de Pernambuco com base numa revisão da literatura e apresentar novos dados obtidos a partir de recentes coletas de carrapatos realizadas nesse estado do nordeste brasileiro. De agosto de 2007 a junho de 2008, 1.405 carrapatos foram coletados e cinco espécies foram identificadas: Amblyomma cajennense (Fabricius, 1787), Amblyomma ovale Koch, 1844, Dermacentor nitens Neumann, 1897, Rhipicephalus (Boophilus) microplus (Canestrini, 1887) e Rhipicephalus sanguineus (Latreille, 1806). Cães de áreas urbanas foram encontrados infestados exclusivamente por R. sanguineus ao passo que cães de áreas rurais foram encontrados parasitados por A. cajennense, A. ovale, R. (B.) microplus e R. sanguineus. A única espécie identificada sobre bovinos e caprinos foi R. (B.) microplus. Equinos foram encontrados infestados por D. nitens e menos frequentemente por A. cajennense e R. (B.) microplus. A única espécie de carrapato encontrada sobre asininos foi D. nitens. Esse estudo confirma a presença de A. cajennense em Pernambuco e registra pela primeira vez a presença de A. ovale nesse estado. A importância médica e veterinária e a situação do controle de carrapatos de animais domésticos em Pernambuco são brevemente discutidas.

A study of ectoparasites of Canis lupus familiaris in Mueang district, Khon Kaen, Thailand.

We studied ectoparasites found on Canis lupus familiaris sampled in five areas in Mueang district, Khon Kaen Province, Thailand. The prevalence of fleas and ticks as well as their density were determined in 100 dogs that did not receive treatments. A total number of 458 ectoparasites was found corresponding to two species: 25.8% Ctenocephalides canis and 74.2% Rhipicephalus sanguineus. R. sanguineus was the most abundant species, and Ct. canis was the only flea species found. The stages of R. sanguineus were larvae (5.3%), nymphs (29.1%) and adults (39.1% in male and 26.5% in female). The stages of Ct. canis were larvae (41.5%) and adults (58.5%). Both species were commonly found on domestic dogs in all areas of the study. Ct. canis was not present on domestic dogs in one sub-district. The prevalence rates of tick-harboring domestic dogs was 80% (R. sanguineus), and flea-haboring domestic dogs was 26% (Ct. canis).

Dinâmica populacional de Boophilus microplus (Canestrini, 1887) em bovinos leiteiros mantidos em manejo de pastejo rotativo de capim-elefante / Populational dynamics of Boophilus microplus (Canestrini, 1887) in dairy cattle under intensively grazing elephant grass pasture

De maio de 1996 a abril de 1998, avaliou-se a dinâmica do parasitismo pelo Boophilus microplus em 20 novilhas mestiças, submetidas ao manejo de rotaçao em piquetes de capim-elefante. Os animais, pesados a cada seis meses, foram distribuídos em dois grupos de 10, sendo realizados tratamentos acaricidas em um deles (grupo tratado). As curvas de infestaçäo nos grupos controle e tratado apresentaram padröes semelhantes, com picos de parasitismo ocorrendo na mesma época. A menor carga parasitária ocorreu no inverno. Na primavera houve um grande pico de infestaçäo por carrapatos, seguido de outro maior em fevereiro. A partir do outono, a carga parasitária declinou naturalmente. Näo se obteve associaçäo entre a dinâmica da infestaçäo pelo B. microplus e variáveis climáticas analisadas (P>0,05). Näo houve diferença estatística entre as médias de peso dos dois lotes (P>0,05). Observou-se que os picos de fêmeas ingurgitadas nos bovinos corresponderam às quedas nos valores de hemoglobina nestes animais (P<0,01). A dinâmica do parasitismo pelo B. microplus em bovinos sob manejo de rotaçäo de pastagens de capim-elefante mostrou-se semelhante a outros trabalhos conduzidos sob manejo convencional sem o uso de rotaçäo

A review of the ticks (Acari, Ixodida) of Brazil, their hosts and geographic distribution - 1. The State of Rio Grande do Sul, Southern Brazil

A review of the ticks (Acari, Ixodida) of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. The ticks: Argas miniatus (poultry), Ixodes loricatus (opossums), Amblyomma aureolatum (dogs), A. calcaratum (anteaters), A. cooperi (capybaras), A. nodosum (anteaters), A. tigrinum (dogs) (Neotropical) and Rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, Afrotropical) were confirmed as present, in addition to the predominant, Boophilus microplus (cattle) (introduced, pan-tropical, Oriental). Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations) (Neotropical), Ixodes affinis (deer) (Nearctic/Neotropical) and I. auritulus (birds) (Nearctic/Neotropical/Afrotropical/ Australasian) are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean) are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses)(Nearctic/Neotropical), but still apparent absence of the tropical A. cajennense (catholic) (Nearctic/Neotropical) and the sub-tropical/temperate Ixodes pararicinus (cattle) (Neotropical) in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic"), Old World tick species (B. microplus, R. sanguineus) that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens), as both long established and possibly newly locally introduced species in the state, that should be considered as potential and emergent pests and pathogen vectors to humans and their more recently acquired, introduced domestic animal hosts; rural poultry, dogs and horses.

Seasonal incidence and hemoparasite infection rates of Ixodid ticks (Acari: Ixodidae) detached from cattle in Costa Rica

To determine the tick species hindering the cattle industry in Costa Rica and to assess infection rates of ticks with three important hemoparasite species, cattle were monitored during a period of six months (October 1992-March 1993). Four farms were located in the dry pacific region of the canton of Tilar n and a fifth farm on the slopes of the Po s volcano in a cool tropical cloud-forest ecosystem. On each farm 3 to 5 animals of 6 to 24 months of age were selected at random. All ticks were removed on a monthly basis from the right half side of each animal, while the site of attachment was recorded. Ticks were counted and differentiated according to species, developmental stage and sex. Moreover, engorged female ticks were assayed for the presence of Babesia bigemina, Babesia bovis and Anaplasma marginale using the polymerase chain reaction (PCR) multiplex system. Two species of ticks, Amblyomma cajennense and Boophilus microplus, were encountered on the cattle in the Tilarán region and one species, B. microplus, was detected in the Poás region. Two to ten times as many ticks were encountered in the Tilarán region than in the Poás region, which is in accordance with a stable enzootic protozoan disease situation in the former region and an unstable epizootic situation in the latter region. Nymphal and adult stages of both tick species were present in largest numbers on the ventral parts of the animals. PCR analysis of entire ticks indicated very high infection rates with hemoparasites of veterinary importance. This was in accordance with high seroprevalence rates in the hosts

A technique for collecting saliva from the cattle-tick Boophilus microplus (canestrini, 1887) using chemical stimulation: environmental and temporal influences on secretion yield

1. Injection of a pilocarpine solution into the hemocoele of female B. microplus through the respiratory spiracle induced the flow of limpid saliva, collected from the mouth parts with a capillary tube. 2. The time interval between the detachment of the tick from its host and chemical stimulation influenced the volume of saliva secreted; secretion was greater during the first 2 h after detachment. 3. There is a positive correlation between salivary yield and both environmental temperature and relative humidity

Parthenogenesis and effect of lack of mating on development and fecundity in hyalomma [H] anatolicum excavatum Koch, 1844

The results suggest that parthenogenesis has no role in development of H. anatolicum excavatum populations in nature. In the absence of males, feeding period is prolonged, females do not fully engorge, are smaller in size, and lay fewer eggs with a greatly reduced viability. However, hatching of a few unfertilized eggs must be considered in performing hybridization experiments