Investigation of the parasitoid Ixodiphagus hookeri (Hymenoptera: Encyrtidae) in Amblyomma sculptum (Acari: Ixodidae) ticks in the municipality of Salto, São Paulo, Brazil

The presence of capybaras (Hydrochoerus hydrochaeris) in urban and periurban areas has caused increased numbers of cases of Brazilian spotted fever. With the aim of investigating the presence of the parasitoid Ixodiphagus hookeri in Amblyomma sculptum ticks in the municipality of Salto, state of São Paulo, samples were collected monthly from 14 sites. Thirty samples were placed in containers for observation of the emergence of microhymenopterans and 88 samples were subjected to molecular testing to identify the presence of I. hookeri DNA. Neither dissections nor observation of emergence indicated any presence of I. hookeri larvae in ticks. Samples subjected to polymerase chain reaction (PCR) amplification of the mCOX I region of I. hookeri did not reveal its presence, although fragments corresponding to mRNA 16S of Amblyomma sculptum ticks were amplified in all samples tested.

Integrated tick control on a farm with the presence of capybaras in a Brazilian spotted fever endemic region.

Ticks of the Amblyomma cajennense complex present high infestation rates. These ticks transmit the bacterium Rickettsia rickettsii, which causes Brazilian Spotted Fever. For this reason, an integrated tick control system was adopted on a farm in the municipality of Itu, state of São Paulo. On this farm, which borders the Tietê river, domestic animals are in contact with populations of capybaras. Six locations were monitored and evaluated between the years of 2015 and 2017. During this work 1271 nymphs and adult ticks were caught, all of them from the Amblyomma sculptum species, except for a single individual from the Amblyomma dubitatum species. The integrated tick management reduced the overall infestation levels to zero. Adult tick population dropped in the first year of the study, while larvae population dropped in the second year. Nymph population dropped in both years, decreasing in higher numbers in the first year. The estimated mean infestation levels for all of the tick's life cycle forms in the six monitored spots did not reach one individual in the end of the study. Estimated mean infestation levels for nymphs in these places equaled zero.

Integrated tick control on a farm with the presence of capybaras in a Brazilian spotted fever endemic region / Controle integrado do carrapato em uma fazenda com presença de capivaras em região endêmica para febre maculosa brasileira

Abstract Ticks of the Amblyomma cajennense complex present high infestation rates. These ticks transmit the bacterium Rickettsia rickettsii, which causes Brazilian Spotted Fever. For this reason, an integrated tick control system was adopted on a farm in the municipality of Itu, state of São Paulo. On this farm, which borders the Tietê river, domestic animals are in contact with populations of capybaras. Six locations were monitored and evaluated between the years of 2015 and 2017. During this work 1271 nymphs and adult ticks were caught, all of them from the Amblyomma sculptum species, except for a single individual from the Amblyomma dubitatum species. The integrated tick management reduced the overall infestation levels to zero. Adult tick population dropped in the first year of the study, while larvae population dropped in the second year. Nymph population dropped in both years, decreasing in higher numbers in the first year. The estimated mean infestation levels for all of the tick's life cycle forms in the six monitored spots did not reach one individual in the end of the study. Estimated mean infestation levels for nymphs in these places equaled zero.

Resumo Em virtude de alta infestação por carrapatos do complexo Amblyomma cajennense, parasitos que transmitem a bactéria Rickettsia rickettsii, causadora da Febre Maculosa Brasileira, adotou-se um sistema de controle integrado dos carrapatos numa propriedade rural localizada no munícipio de Itu - SP. Na propriedade, que margeia o rio Tietê, os animais domésticos mantinham contato com populações de capivaras. Seis locais foram avaliados e monitorados nos anos de 2015 a 2017. Dentre os 1271 espécimes capturados (adultos e ninfas) um foi identificado como Amblyomma dubitatum e os demais com Amblyomma sculptum. De um modo geral, houve controle da infestação de carrapatos visto que todos os estágios ao final de 2017 apresentaram níveis próximos ou igual a zero. A população de adultos teve queda no primeiro ano e a de larvas no segundo. As ninfas apresentaram queda nos dois anos, sendo mais acentuada no primeiro ano. A média da estimativa do nível de infestação para cada estágio do carrapato nos seis locais monitorados não chegou a 1 indivíduo ao final do experimento, sendo que a média da estimativa para as ninfas foi de zero em todos esses locais.

Demodex phylloides infection in swine reared in a peri-urban family farm located on the outskirts of the Metropolitan Region of São Paulo, Brazil.

This paper reports the occurrence of porcine demodicosis caused by the mite Demodex phylloides in hogs reared in a peri-urban family farm located in Francisco Morato, a municipality of the Metropolitan Region of São Paulo, capital city of the state of São Paulo, Brazil. In a parcel of forty Landrace - Large White cross hogs, approximately four months old, four animals presented severe skin lesions in the form of small nodules over their entire body, especially in the periocular region, snout, lower abdomen and flanks. Two hogs had to be euthanized for animal welfare reasons, which enabled post-mortem examination. Skin scrapings revealed eggs, larvae, nymphs and adults of D. phylloides. Purulent subcutaneous nodules with intense parasitic folliculitis and intense perifollicular inflammatory reaction were present. Enterobacteria and coagulase-positive Staphylococcus spp. were isolated from the skin pustules. Necropsy revealed milk spotted liver, enteritis and enlargement of mesenteric lymph nodes. Protozoa (Eimeria spp. and Balantidium sp.), helminth eggs (Ascaris suum, Trichuris suis and strongyles) and Brachyspira spp. were found in faeces. Staphylococcus spp. and enterobacteria were isolated from internal organs. All remaining hogs were treated with ivermectin at a daily oral dose of 0.45g/kg of feed, during seven days. Fifteen days after treatment, remission of symptoms was observed in the surviving animals with demodicosis; absence of mites was confirmed by skin scraping examinations. The hogs were reared under poor environmental, nutritional and sanitary conditions, resulting in multimorbidity and immunosuppression. Severe clinical porcine demodicosis was triggered when the animals were castrated. Family pig farmers had been suffering economic losses due to the stunted growth of the herd. In addition to that, the lesions found on the skin and in the internal organs would result in condemnation of meat and viscera for human consumption. As part of a Public Policies Project, farm facilities were renovated with governmental aid, while family farmers received training. Good management practices and biosecurity measures were introduced in the herd. Educative policies and financial support were important to guide family pig farmers towards better husbandry practices, allowing them to raise healthy hogs in compliance with market demands.