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Alberto A. Guglielmone - One of the best experts on this subject based on the ideXlab platform.
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Tick Classification, External Tick Anatomy with a Glossary, and Biological Cycles
Ticks of the Southern Cone of America, 2017Co-Authors: Santiago Nava, José M. Venzal, Daniel González-acuña, Thiago F. Martins, Alberto A. GuglielmoneAbstract:The superfamily Ixodoidea contains the families Argasidae (208 species), Ixodidae (722 species), and the African Nuttalliellidae (monotypic). Argasidae is formed by five genera with three present in the Southern Cone of America: Argas , Ornithodoros , and Otobius , while there are 12 extant genera of Ixodidae and 5 are established in the region: Amblyomma , Dermacentor , Haemaphysalis , Ixodes , and Rhipicephalus . Ixodidae is divided into Prostriata and Metastriata groups; the first group contains the genus Ixodes and the second the remainder genera. Main external morphological characters with relevance for genera and species differentiation are described and figured in a glossary for these main characters. The parasitic cycles of Ixodidae are one-, two-, or three-host cycles, while most species of Argasidae have a multihost life cycle but one species, Otobius megnini (present in the region) has a one-host cycle and another, Argas lahorensis (not established in the region), has a two-host cycle but the parasitic sequence of many species remains unknown.
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Morphological Keys for Genera and Species of Ixodidae and Argasidae
Ticks of the Southern Cone of America, 2017Co-Authors: Santiago Nava, José M. Venzal, Daniel González-acuña, Thiago F. Martins, Alberto A. GuglielmoneAbstract:Dichotomous keys using morphological external characters were constructed to identify genera and species of Argasidae and Ixodidae, except the genera Dermacentor (Ixodidae) and Otobius (Argasidae) with only one species each in the Southern Cone of America. No key for ixodid larvae is given due to insufficient information. Males, females, and nymphs of all Amblyomma (25 species), Haemaphysalis (2), and Rhipicephalus (2 species) are included but 6 males and 5 nymphs of the 16 species of Ixodes are unknown or imprecisely described. The situation for Argasidae (5 Argas and 12 Ornithodoros ) is different because larvae morphology is relevant for specific diagnosis, especially for Ornithodoros , and less so for adult ticks. Therefore, keys are presented for larvae and adult ticks as differences between male and female ticks are morphologically irrelevant, but adult ticks of five species of Ornithodoros are unknown. No keys for nymphs of Argasidae are presented because their external characters are similar to the corresponding adults.
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Genera and Species of Argasidae
Ticks of the Southern Cone of America, 2017Co-Authors: Santiago Nava, José M. Venzal, Daniel González-acuña, Thiago F. Martins, Alberto A. GuglielmoneAbstract:Distribution, hosts, notes on ecology, and sanitary importance along with taxonomical considerations and morphological diagnosis for adults and larvae are provided for the 18 species of Argasidae (5 Argas , 12 Ornithodoros , and 1 species of Otobius ) established in the Southern Cone of America. A condensed phylogenetic tree based on mitochondrial 16S rDNA sequences is included to show the relationship among species. There is controversy about the presence of A. miniatus and A. persicus but we provisionally considered both as found in the region. Or. capensis is treated as established in one southern country (Chile) by other workers but this fact is still unproven. Several species are of medical relevance but additional efforts have to be made to know their role as vector of diseases. The genus Ornithodoros is of special phylogenetic interest and deserves additional studies to understand life history of Argasidae, and to find adults of some species that are known only by the larva.
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the ticks acari ixodida argasidae ixodidae of bolivia
Ticks and Tick-borne Diseases, 2014Co-Authors: Mariano Mastropaolo, Fabian L Beltransaavedra, Alberto A. GuglielmoneAbstract:Abstract The tick species reported in Bolivia are reviewed here as (1) endemic or established: Ornithodoros echimys , O. guaporensis , O. hasei , O. kohlsi , O. mimon , O. peropteryx , O. rostratus , Otobius megnini , Amblyomma auricularium , A. cajennense , A. calcaratum , A. coelebs , A. dubitatum , A. humerale , A. incisum , A. longirostre , A. naponense , A. nodosum , A. oblongoguttatum , A. ovale , A. parvitarsum , A. parvum , A. pecarium , A. pseudoconcolor , A. rotundatum , A. scalpturatum , A. tigrinum , A. triste , Dermacentor nitens , Haemaphysalis juxtakochi , H. leporispalustris , I. boliviensis , I. cooleyi , I. luciae , Rhipicephalus microplus , R. sanguineus , and (2) erroneously reported: Ornithodoros puertoricensis , O. talaje , O. turicata , Amblyomma americanum , A. maculatum , A. multipunctum , Ixodes ricinus , I. scapularis , Rhipicephalus annulatus . Many of these records are lacking locality and/or host, and some of them need new findings for confirmation. Some of the species recorded may represent a threat for human and animal health, therefore would be of great value to make a countrywide survey of ticks in order to update the information presented in this work.
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Developmental Changes in Salivary Glands of Nymphs and Adults of the Spinose Ear Tick Otobius megnini
The Journal of parasitology, 2011Co-Authors: Mariano Mastropaolo, Alberto A. Guglielmone, Santiago Nava, A. J. MangoldAbstract:Abstract Otobius megnini has an autogenous 1 host life cycle, where larvae and nymphs stay attached inside the ear canal for long periods, but the adult tick is free living and can lay several egg batches without feeding. In order to obtain information about anatomical structures involved in this particular life cycle, nymphs and adults of O. megnini were dissected and salivary gland images were obtained in situ with the use of scanning electronic microscopy. Measurements of salivary alveoli were obtained with the use of ImageJ 1.40g software. In the nymphs, the Type I alveoli are relatively small (mean diameter: 19.6 µm) compared with those of the adults (mean: 43.4 µm) and other soft ticks in the literature. Type II alveoli in nymphs are similar (mean: 82.6 µm) to previously described alveoli in adult soft ticks. In contrast, the adults of O. megnini Type II alveoli are smaller (mean: 36.8 µm) and have a wrinkled surface. These findings provide more evidence that Type I alveoli take part in absorption o...
R.s. Rajakaruna - One of the best experts on this subject based on the ideXlab platform.
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Molecular evidence of Babesia infections in Spinose ear tick, Otobius megnini infesting stabled horses in Nuwara Eliya racecourse: A case study
Ceylon Journal of Science, 2018Co-Authors: G.c.p. Diyes, R.p.v.j. Rajapakse, R.s. RajakarunaAbstract:Spinose ear tick, Otobius megnini (Family Argasidae) is a one-host soft tick that parasitizes domesticated animals and occasionally humans. It causes otoacariasis or parasitic otitis in humans and animals and also known to carry infectious agents. Intra aural infestations of O. megnini is a serious health problem in the well-groomed race horses in Nuwara Eliya. Otobius megnini collected from the ear canal of stabled horses in Nuwara Eliya racecourse were tested for three possible infections, Rickettsia, Theileria and Babesia. Genomic DNA was extracted from 22 ticks collected from 11 horses and then pathogen-specific DNA was amplified using PCR. Ticks from two horses (one thoroughbred and one stallion) tested PCR positive for Babesia but not for other infections. None of the horses however, showed any clinical symptoms of babesiosis. This is the first record of Babesia infections in O. megnini. However, the presence of Babesia DNA in O. megnini doesn’t qualify it as the vector of equine babesiosis, horse blood has to be tested for the presence of parasite DNA or antibodies.
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Ants as predators of the Spinose Ear Tick, Otobius megnini (Dugès) in Sri Lanka
Acarologia, 2017Co-Authors: G.c.p. Diyes, Nuwan B. Karunarathna, T.h.s.e. Silva, W. A. I. P. Karunaratne, R.s. RajakarunaAbstract:Many pathogens, parasitoids and predators have been documented as natural enemies of ticks, but their impact on tick populations are rarely evaluated. Here, we report the predatory behaviour of ants on the spinose ear tick, Otobius megnini. Ticks were collected from the ear canal of stabled horses in Nuwara Eliya and were brought to the laboratory. Eggs, unfed and engorged larvae, engorged nymphs and adults were naturally exposed to ants under laboratory conditions and the predatory behaviour of the different species and their feeding preferences were observed. Five ant species were found feeding on different life stages of O. megnini including eggs, larvae (fed/unfed) and adults; ants did not feed on the nymphal stages. Ant species were identified as Tapinoma melanocephalum, two species of Monomorium, one species of Pheidole and one species of Crematogaster. The predatory preference differed among the five ant species, with T. melanocephalum being identified as the best predator as it fed on eggs and adults, the non-parasitic stages of O. megnini. Different strategies have been used to control the infestations of O. megnini in the stabled horses but none of them were successful. Although we cannot extrapolate our empirical findings to a natural context, observations suggest that these ant species may be potential bio-suppressors of this tick species.
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life cycle of spinose ear tick Otobius megnini acari argasidae infesting the race horses in nuwara eliya sri lanka
Acta Tropica, 2017Co-Authors: G.c.p. Diyes, R.s. RajakarunaAbstract:Abstract Otobius megnini infests mainly domesticated and wild animals and occasionally humans. It has been identified as an agent of human and horse otoacariasis in Sri Lanka. The number of nymphal stages in the life cycle of O. megnini varies from one to three in different geographic regions. The present study determined the life cycle of O. megnini infesting the racehorses in Nuwara Eliya. A tick colony was initiated from fully engorged nymphs collected from horses and maintained at 10 °C, 22 °C and 28 °C. Immature stages were reared on New Zealand rabbits. Only the larvae weighing more than 0.9 mg (84.9%) moulted to nymphs with a pre-moulting period of 5.6(±1.7) days. None of the larvae maintained at 10 ± 1 °C moulted. Larval survival was significantly higher at 28 ± 1 °C (44.2 ± 4.3 days) than at 22 ± 1 °C (35.6 ± 9 days). At 28 ± 1 °C, majority of nymphs (95.6%) weighing over 10 mg moulted into adults within 12.5(±3.1) days. Nymphs kept at 10 ± 1 °C underwent diapause for 81.1(±72.0) days. Larger females (>13 mg; 93.0%) laid eggs for of 44.6(±17.8) days with a mean pre-oviposition period of 10.3(±5.1) days. Females survived longer (369.8 ± 128.3 days) than males (210.4 ± 54.1 days; Student’s t-test; t = 5.9, p = 0.001). Some females laid eggs without mating. Otobius megnini successfully completed the life cycle within 123 days and has only one nymphal instar similar to the Neotropical population. Currently, O. megnini infestation is a serious problem to horses in the Nuwara Eliya racecourse and may pose a risk of spreading to dairy farms close by owing to its dynamic nature of the life cycle.
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Life cycle of Spinose ear tick, Otobius megnini (Acari: Argasidae) infesting the race horses in Nuwara Eliya, Sri Lanka
Acta tropica, 2016Co-Authors: G.c.p. Diyes, R.s. RajakarunaAbstract:Abstract Otobius megnini infests mainly domesticated and wild animals and occasionally humans. It has been identified as an agent of human and horse otoacariasis in Sri Lanka. The number of nymphal stages in the life cycle of O. megnini varies from one to three in different geographic regions. The present study determined the life cycle of O. megnini infesting the racehorses in Nuwara Eliya. A tick colony was initiated from fully engorged nymphs collected from horses and maintained at 10 °C, 22 °C and 28 °C. Immature stages were reared on New Zealand rabbits. Only the larvae weighing more than 0.9 mg (84.9%) moulted to nymphs with a pre-moulting period of 5.6(±1.7) days. None of the larvae maintained at 10 ± 1 °C moulted. Larval survival was significantly higher at 28 ± 1 °C (44.2 ± 4.3 days) than at 22 ± 1 °C (35.6 ± 9 days). At 28 ± 1 °C, majority of nymphs (95.6%) weighing over 10 mg moulted into adults within 12.5(±3.1) days. Nymphs kept at 10 ± 1 °C underwent diapause for 81.1(±72.0) days. Larger females (>13 mg; 93.0%) laid eggs for of 44.6(±17.8) days with a mean pre-oviposition period of 10.3(±5.1) days. Females survived longer (369.8 ± 128.3 days) than males (210.4 ± 54.1 days; Student’s t-test; t = 5.9, p = 0.001). Some females laid eggs without mating. Otobius megnini successfully completed the life cycle within 123 days and has only one nymphal instar similar to the Neotropical population. Currently, O. megnini infestation is a serious problem to horses in the Nuwara Eliya racecourse and may pose a risk of spreading to dairy farms close by owing to its dynamic nature of the life cycle.
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Diversity and distribution of tick species (Acari: Ixodidae) associated with human otoacariasis and socio-ecological risk factors of tick infestations in Sri Lanka
Experimental and Applied Acarology, 2016Co-Authors: S. Ariyarathne, D. A. Apanaskevich, P. H. Amarasinghe, R.s. RajakarunaAbstract:Tick infestation in humans is a major public health concern. The diversity and distribution of tick species associated with human otoacariasis was studied in five districts: Anuradhapura, Kandy, Kurunegala, Nuwara Eliya and Ratnapura in the main agro-climatic zones of Sri Lanka. Ticks from patients attending the ear, nose and throat clinics of the General Hospitals were collected during a 3 year period. In total 426 ticks were collected. Most human otoacariasis cases were reported from Kandy (33.8 %) and the fewest from Nuwara Eliya (8.2 %). Of the five tick species identified, nymphs of Dermacentor auratus constituted 90.6 % of the collection. Rhipicephalus sanguineus, Hyalomma isaaci, Haemaphysalis bispinosa and Otobius megnini were found rarely infesting humans possibly as an accidental host; H. bispinosa and O. megnini in the human ear canal were first time records in Sri Lanka. Females and children under 10 years were identified as risk groups of human otoacariasis. Subsequently, a field study was carried out to determine socio-ecological risk factors of human tick infestations in the five districts. Based on hospital data, eight villages with high prevalence of otoacariasis were selected from each district. A total 40 villages were visited and 1674 household members were interviewed. Involvement in outdoor activities, presence of wild animals around the house, location of the house in close proximity to a forest and occupation were identified as major risk factors.
G.c.p. Diyes - One of the best experts on this subject based on the ideXlab platform.
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Molecular evidence of Babesia infections in Spinose ear tick, Otobius megnini infesting stabled horses in Nuwara Eliya racecourse: A case study
Ceylon Journal of Science, 2018Co-Authors: G.c.p. Diyes, R.p.v.j. Rajapakse, R.s. RajakarunaAbstract:Spinose ear tick, Otobius megnini (Family Argasidae) is a one-host soft tick that parasitizes domesticated animals and occasionally humans. It causes otoacariasis or parasitic otitis in humans and animals and also known to carry infectious agents. Intra aural infestations of O. megnini is a serious health problem in the well-groomed race horses in Nuwara Eliya. Otobius megnini collected from the ear canal of stabled horses in Nuwara Eliya racecourse were tested for three possible infections, Rickettsia, Theileria and Babesia. Genomic DNA was extracted from 22 ticks collected from 11 horses and then pathogen-specific DNA was amplified using PCR. Ticks from two horses (one thoroughbred and one stallion) tested PCR positive for Babesia but not for other infections. None of the horses however, showed any clinical symptoms of babesiosis. This is the first record of Babesia infections in O. megnini. However, the presence of Babesia DNA in O. megnini doesn’t qualify it as the vector of equine babesiosis, horse blood has to be tested for the presence of parasite DNA or antibodies.
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Ants as predators of the Spinose Ear Tick, Otobius megnini (Dugès) in Sri Lanka
Acarologia, 2017Co-Authors: G.c.p. Diyes, Nuwan B. Karunarathna, T.h.s.e. Silva, W. A. I. P. Karunaratne, R.s. RajakarunaAbstract:Many pathogens, parasitoids and predators have been documented as natural enemies of ticks, but their impact on tick populations are rarely evaluated. Here, we report the predatory behaviour of ants on the spinose ear tick, Otobius megnini. Ticks were collected from the ear canal of stabled horses in Nuwara Eliya and were brought to the laboratory. Eggs, unfed and engorged larvae, engorged nymphs and adults were naturally exposed to ants under laboratory conditions and the predatory behaviour of the different species and their feeding preferences were observed. Five ant species were found feeding on different life stages of O. megnini including eggs, larvae (fed/unfed) and adults; ants did not feed on the nymphal stages. Ant species were identified as Tapinoma melanocephalum, two species of Monomorium, one species of Pheidole and one species of Crematogaster. The predatory preference differed among the five ant species, with T. melanocephalum being identified as the best predator as it fed on eggs and adults, the non-parasitic stages of O. megnini. Different strategies have been used to control the infestations of O. megnini in the stabled horses but none of them were successful. Although we cannot extrapolate our empirical findings to a natural context, observations suggest that these ant species may be potential bio-suppressors of this tick species.
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life cycle of spinose ear tick Otobius megnini acari argasidae infesting the race horses in nuwara eliya sri lanka
Acta Tropica, 2017Co-Authors: G.c.p. Diyes, R.s. RajakarunaAbstract:Abstract Otobius megnini infests mainly domesticated and wild animals and occasionally humans. It has been identified as an agent of human and horse otoacariasis in Sri Lanka. The number of nymphal stages in the life cycle of O. megnini varies from one to three in different geographic regions. The present study determined the life cycle of O. megnini infesting the racehorses in Nuwara Eliya. A tick colony was initiated from fully engorged nymphs collected from horses and maintained at 10 °C, 22 °C and 28 °C. Immature stages were reared on New Zealand rabbits. Only the larvae weighing more than 0.9 mg (84.9%) moulted to nymphs with a pre-moulting period of 5.6(±1.7) days. None of the larvae maintained at 10 ± 1 °C moulted. Larval survival was significantly higher at 28 ± 1 °C (44.2 ± 4.3 days) than at 22 ± 1 °C (35.6 ± 9 days). At 28 ± 1 °C, majority of nymphs (95.6%) weighing over 10 mg moulted into adults within 12.5(±3.1) days. Nymphs kept at 10 ± 1 °C underwent diapause for 81.1(±72.0) days. Larger females (>13 mg; 93.0%) laid eggs for of 44.6(±17.8) days with a mean pre-oviposition period of 10.3(±5.1) days. Females survived longer (369.8 ± 128.3 days) than males (210.4 ± 54.1 days; Student’s t-test; t = 5.9, p = 0.001). Some females laid eggs without mating. Otobius megnini successfully completed the life cycle within 123 days and has only one nymphal instar similar to the Neotropical population. Currently, O. megnini infestation is a serious problem to horses in the Nuwara Eliya racecourse and may pose a risk of spreading to dairy farms close by owing to its dynamic nature of the life cycle.
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Life cycle of Spinose ear tick, Otobius megnini (Acari: Argasidae) infesting the race horses in Nuwara Eliya, Sri Lanka
Acta tropica, 2016Co-Authors: G.c.p. Diyes, R.s. RajakarunaAbstract:Abstract Otobius megnini infests mainly domesticated and wild animals and occasionally humans. It has been identified as an agent of human and horse otoacariasis in Sri Lanka. The number of nymphal stages in the life cycle of O. megnini varies from one to three in different geographic regions. The present study determined the life cycle of O. megnini infesting the racehorses in Nuwara Eliya. A tick colony was initiated from fully engorged nymphs collected from horses and maintained at 10 °C, 22 °C and 28 °C. Immature stages were reared on New Zealand rabbits. Only the larvae weighing more than 0.9 mg (84.9%) moulted to nymphs with a pre-moulting period of 5.6(±1.7) days. None of the larvae maintained at 10 ± 1 °C moulted. Larval survival was significantly higher at 28 ± 1 °C (44.2 ± 4.3 days) than at 22 ± 1 °C (35.6 ± 9 days). At 28 ± 1 °C, majority of nymphs (95.6%) weighing over 10 mg moulted into adults within 12.5(±3.1) days. Nymphs kept at 10 ± 1 °C underwent diapause for 81.1(±72.0) days. Larger females (>13 mg; 93.0%) laid eggs for of 44.6(±17.8) days with a mean pre-oviposition period of 10.3(±5.1) days. Females survived longer (369.8 ± 128.3 days) than males (210.4 ± 54.1 days; Student’s t-test; t = 5.9, p = 0.001). Some females laid eggs without mating. Otobius megnini successfully completed the life cycle within 123 days and has only one nymphal instar similar to the Neotropical population. Currently, O. megnini infestation is a serious problem to horses in the Nuwara Eliya racecourse and may pose a risk of spreading to dairy farms close by owing to its dynamic nature of the life cycle.
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Seasonal dynamics of spinose ear tick Otobius megnini associated with horse otoacariasis in Sri Lanka.
Acta tropica, 2016Co-Authors: G.c.p. Diyes, R.s. RajakarunaAbstract:Otobius megnini is a one host, nidicolous soft tick (Family Argasidae) whose larvae and nymphs parasitize the external ear canal of many wild and domestic animals and occasionally humans. The present study was conducted to determine the seasonal dynamics of O. megnini infesting stabled horses in Nuwara Eliya racecourses. Ticks were sampled biweekly for two years from May 2013 to May 2015 from the ear canal of seven thoroughbred male horses. Weather data: temperature, rainfall and humidity for the study period were obtained from the Meteorological Department, Colombo. A total of 23, 287 ticks of O. megnini were collected from the ear canal of horses and all of which were immature stages comprising 41.4% larvae and 59.6% nymphs. Larval counts were high during warmer months of the year with minimum numbers recording September-November. High larval abundance may be due to the high hatching rate of eggs at high temperatures. Larval abundance was significantly affected by maximum temperature, minimum relative humidity and average relative humidity (Multiple regression; r(2)=0.5, F=3.7, p=0.01). Population peaks for nymphs occurred in May, October and January. Nymph counts were low in March and April. Weather conditions did not have any correlation with the abundance of nymphs. Rainfall had no effect on both larvae and nymph counts. Even though control measures have been taken, O. megnini infestation is a serious problem for the stable owners especially because these horses are used in racing and other recreational purposes. Further, there is a high risk of spreading this tick within the country due to the presence of suitable hosts and the adaptability of the tick to survive in changing climatic conditions. Information on the seasonal dynamics of the tick population is important for employing control measures.
David H. Kattes - One of the best experts on this subject based on the ideXlab platform.
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Spatial and temporal distributions of the Spinose Ear Tick, Otobius megnini, within animal shelters at Fossil Rim Wildlife Center
The Southwestern Naturalist, 2015Co-Authors: Callie J. Price, David H. Kattes, Kristin K. Herrmann, Christopher L. HigginsAbstract:Abstract Spinose ear ticks, Otobius megnini, are monoxenous parasites that feed within the ear of ungulates, subjecting them to debilitating conditions. Little is known about the spatial dispersion of spinose ticks in animal shelters or the temporal variation in their abundance. Therefore, the objectives of this study were to: 1) determine the temporal distribution of spinose ear tick abundance within animal shelters, 2) determine the spatial distribution of larvae and adults within animal shelters, and 3) examine the effects of climatic variables on tick abundance. No temporal trend was identified for larval or adult ticks. Larval abundance was highest in quadrats located against the shelter wall while no spatial difference was found in adult abundance. Mean larval tick abundance was significantly correlated with mean temperature while mean adult tick abundance was significantly correlated with mean relative humidity.
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Efficacy of chemical repellents against Otobius megnini (Acari: Argasidae) and three species of ixodid ticks
Experimental and Applied Acarology, 2014Co-Authors: Chris N Niebuhr, Jeff B. Breeden, Sarah E. Mays, Barry D. Lambert, David H. KattesAbstract:Otobius megnini (Dugès), often referred to as the ear tick or spinose ear tick, is a one-host tick native to the southwestern United States and Mexico. Infestations of this species can cause severe irritation and may affect breeding behavior in the host. Although chemical repellents are commonly used as an alternative approach to conventional arthropod vector control, information on repellency against O. megnini is lacking. This study compared repellency of ammonia, BioUD^®, 98.25 % DEET, garlic pepper tea, permanone, and pyrethrin with piperonyl butoxide, against larvae stages of O. megnini , Amblyomma americanum (L.), Dermacentor variabilis (Say), and Rhipicephalus sanguineus (Latreille). To test for repellency, tick movement was recorded at 30 s intervals for five min after introduction to a partially treated piece of filter paper. Results showed larvae of O. megnini exhibited less aversion to the chemicals tested when compared to the other tick species.
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Efficacy of chemical repellents against Otobius megnini (Acari: Argasidae) and three species of ixodid ticks
Experimental & applied acarology, 2014Co-Authors: Chris N Niebuhr, Jeff B. Breeden, Sarah E. Mays, Barry D. Lambert, David H. KattesAbstract:Otobius megnini (Duges), often referred to as the ear tick or spinose ear tick, is a one-host tick native to the southwestern United States and Mexico. Infestations of this species can cause severe irritation and may affect breeding behavior in the host. Although chemical repellents are commonly used as an alternative approach to conventional arthropod vector control, information on repellency against O. megnini is lacking. This study compared repellency of ammonia, BioUD®, 98.25 % DEET, garlic pepper tea, permanone, and pyrethrin with piperonyl butoxide, against larvae stages of O. megnini, Amblyomma americanum (L.), Dermacentor variabilis (Say), and Rhipicephalus sanguineus (Latreille). To test for repellency, tick movement was recorded at 30 s intervals for five min after introduction to a partially treated piece of filter paper. Results showed larvae of O. megnini exhibited less aversion to the chemicals tested when compared to the other tick species.
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off host collection methods of the Otobius megnini acari argasidae
Journal of Medical Entomology, 2013Co-Authors: Chris N Niebuhr, Jeff B. Breeden, B D Lambert, A I Eyres, H J Haefele, David H. KattesAbstract:ABSTRACT Otobius megnini (Duges), often referred to as the spinose ear tick, is a one-host tick infesting the ear canal of a variety of ungulate species. The objective of this study was to develop sampling methods for collecting free-living stages of O. megnini and to collect preliminary data on habitat distribution. Sampling occurred during 2010 and 2011 at Fossil Rim Wildlife Center (FRWC) near Glen Rose, TX, where tick presence has been observed in the ears of a variety of ungulates. To sample for nonfeeding adult stage presence, a debris-filtering method was developed using screens of varying gauges. To sample host-seeking larval-stage tick presence, a carbon dioxide (CO2 ) trap was developed using compressed CO2 released through tubing along with cotton fabric used for tick attachment. Both methods proved successful with adults and larvae collected from animal shelters, with larvae also collected from oak leaf litter away from any structure. Locating both life stages off the host is the first crucial...
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Off-Host Collection Methods of the Otobius megnini (Acari: Argasidae)
Journal of medical entomology, 2013Co-Authors: Chris N Niebuhr, Jeff B. Breeden, A I Eyres, H J Haefele, Barry D. Lambert, David H. KattesAbstract:Otobius megnini (Duges), often referred to as the spinose ear tick, is a one-host tick infesting the ear canal of a variety of ungulate species. The objective of this study was to develop sampling methods for collecting free-living stages of O. megnini and to collect preliminary data on habitat distribution. Sampling occurred during 2010 and 2011 at Fossil Rim Wildlife Center (FRWC) near Glen Rose, TX, where tick presence has been observed in the ears of a variety of ungulates. To sample for nonfeeding adult stage presence, a debris-filtering method was developed using screens of varying gauges. To sample host-seeking larval-stage tick presence, a carbon dioxide (CO2) trap was developed using compressed CO2 released through tubing along with cotton fabric used for tick attachment. Both methods proved successful with adults and larvae collected from animal shelters, with larvae also collected from oak leaf litter away from any structure. Locating both life stages off the host is the first crucial step toward the management of this tick species at facilities such as FRWC.
Santiago Nava - One of the best experts on this subject based on the ideXlab platform.
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Tick Classification, External Tick Anatomy with a Glossary, and Biological Cycles
Ticks of the Southern Cone of America, 2017Co-Authors: Santiago Nava, José M. Venzal, Daniel González-acuña, Thiago F. Martins, Alberto A. GuglielmoneAbstract:The superfamily Ixodoidea contains the families Argasidae (208 species), Ixodidae (722 species), and the African Nuttalliellidae (monotypic). Argasidae is formed by five genera with three present in the Southern Cone of America: Argas , Ornithodoros , and Otobius , while there are 12 extant genera of Ixodidae and 5 are established in the region: Amblyomma , Dermacentor , Haemaphysalis , Ixodes , and Rhipicephalus . Ixodidae is divided into Prostriata and Metastriata groups; the first group contains the genus Ixodes and the second the remainder genera. Main external morphological characters with relevance for genera and species differentiation are described and figured in a glossary for these main characters. The parasitic cycles of Ixodidae are one-, two-, or three-host cycles, while most species of Argasidae have a multihost life cycle but one species, Otobius megnini (present in the region) has a one-host cycle and another, Argas lahorensis (not established in the region), has a two-host cycle but the parasitic sequence of many species remains unknown.
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Morphological Keys for Genera and Species of Ixodidae and Argasidae
Ticks of the Southern Cone of America, 2017Co-Authors: Santiago Nava, José M. Venzal, Daniel González-acuña, Thiago F. Martins, Alberto A. GuglielmoneAbstract:Dichotomous keys using morphological external characters were constructed to identify genera and species of Argasidae and Ixodidae, except the genera Dermacentor (Ixodidae) and Otobius (Argasidae) with only one species each in the Southern Cone of America. No key for ixodid larvae is given due to insufficient information. Males, females, and nymphs of all Amblyomma (25 species), Haemaphysalis (2), and Rhipicephalus (2 species) are included but 6 males and 5 nymphs of the 16 species of Ixodes are unknown or imprecisely described. The situation for Argasidae (5 Argas and 12 Ornithodoros ) is different because larvae morphology is relevant for specific diagnosis, especially for Ornithodoros , and less so for adult ticks. Therefore, keys are presented for larvae and adult ticks as differences between male and female ticks are morphologically irrelevant, but adult ticks of five species of Ornithodoros are unknown. No keys for nymphs of Argasidae are presented because their external characters are similar to the corresponding adults.
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Genera and Species of Argasidae
Ticks of the Southern Cone of America, 2017Co-Authors: Santiago Nava, José M. Venzal, Daniel González-acuña, Thiago F. Martins, Alberto A. GuglielmoneAbstract:Distribution, hosts, notes on ecology, and sanitary importance along with taxonomical considerations and morphological diagnosis for adults and larvae are provided for the 18 species of Argasidae (5 Argas , 12 Ornithodoros , and 1 species of Otobius ) established in the Southern Cone of America. A condensed phylogenetic tree based on mitochondrial 16S rDNA sequences is included to show the relationship among species. There is controversy about the presence of A. miniatus and A. persicus but we provisionally considered both as found in the region. Or. capensis is treated as established in one southern country (Chile) by other workers but this fact is still unproven. Several species are of medical relevance but additional efforts have to be made to know their role as vector of diseases. The genus Ornithodoros is of special phylogenetic interest and deserves additional studies to understand life history of Argasidae, and to find adults of some species that are known only by the larva.
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Developmental Changes in Salivary Glands of Nymphs and Adults of the Spinose Ear Tick Otobius megnini
The Journal of parasitology, 2011Co-Authors: Mariano Mastropaolo, Alberto A. Guglielmone, Santiago Nava, A. J. MangoldAbstract:Abstract Otobius megnini has an autogenous 1 host life cycle, where larvae and nymphs stay attached inside the ear canal for long periods, but the adult tick is free living and can lay several egg batches without feeding. In order to obtain information about anatomical structures involved in this particular life cycle, nymphs and adults of O. megnini were dissected and salivary gland images were obtained in situ with the use of scanning electronic microscopy. Measurements of salivary alveoli were obtained with the use of ImageJ 1.40g software. In the nymphs, the Type I alveoli are relatively small (mean diameter: 19.6 µm) compared with those of the adults (mean: 43.4 µm) and other soft ticks in the literature. Type II alveoli in nymphs are similar (mean: 82.6 µm) to previously described alveoli in adult soft ticks. In contrast, the adults of O. megnini Type II alveoli are smaller (mean: 36.8 µm) and have a wrinkled surface. These findings provide more evidence that Type I alveoli take part in absorption o...
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using ground derived data to assess the environmental niche of the spinose ear tick Otobius megnini
Entomologia Experimentalis Et Applicata, 2010Co-Authors: Agustin Estradapena, Ivan Gerard Horak, Santiago Nava, Alberto A. GuglielmoneAbstract:Four layers of environmental information, namely 1) monthly atmospheric temperature and rainfall, 2) annual ground and underground moisture, evaporation, surface adjacent specific humidity, and temperature, 3) monthly Normalized Derived Vegetation Index (NDVI), and 4) soil physical attributes, were used separately to define the expected geographical distribution and environmental niche of the spinose ear tick, Otobius megnini (Duges) (Acari: Ixodida: Argasidae), an endophilic argasid, in both tropical and neotropical regions. The best predictive values were obtained from ground-derived climate. Air-derived features ranked second. The remaining environmental information had poor discriminatory abilities. The most informative variables in the distribution of neotropical populations are ground temperatures, with surface humidity ranking second. In the tropics, surface humidity is the most important factor delineating the distribution of O. megnini. Marginality scores are similar for tick populations in both biogeographical regions, but specialization factors are different, supporting the findings that both populations are regulated by different variables. Similarly, models trained with records of one biogeographical region and projected into the other one, resulted in poorer predictions than when trained with the homologous set of records. Populations of the tick in the tropics experience a different range of temperatures than their neotropical relatives, whereas marginality scores are similar. The conclusion is that each population uses particular portions of the environmental niche, probably because of different climate or competitor constraints on either biogeographical region.
