A meta-analysis of host specificity in Neotropical hard ticks (Acari: Ixodidae)

Host specificity of Neotropical hard ticks (Acari: Ixodidae) was analyzed by using the number of hosts species for each tick species and the index of host specificity STD*, which integrates phylogenetic and ecological information. The analyses were based on 4172 records of hard ticks collected from wild and domestic tetrapods. Most tick species included in this study were associated with three to 20 host species. No tick species has been associated either with a single species or with a single genus of host. It was found that the number of host species is sensitive to sampling effort, but not the STD*. The most frequent values of STD* were between 2.5 and 3.5, which shows that the host species more frequently used by Neotropical hard tick species belong to different families or different orders. Immature stages tend to use a broader taxonomic range of hosts than adults, and the interpretation of both measures of host specificity used in this study led to the conclusion that the impact of non-endemic hosts does not alter the patterns of host specificity in Neotropical hard ticks. The index STD* showed that a high proportion of tick species has phylogenetically unrelated species as principal hosts. The conclusion reached in this work indicates that strict host specificity is not common among Neotropical hard ticks and suggests that the influence of tick ecology and evolution of habitat specificity, tick generation time, phenology, time spent off the host and the type of life-cycle could be more important than hosts species.Fil: Nava, Santiago. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Santa Fe. Estacion Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe; ArgentinaFil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Santa Fe. Estacion Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe; Argentin

Rodents of the subfamily Sigmodontinae (Myomorpha: Cricetidae) as hosts for South American hard ticks (Acari: Ixodidae) with hypotheses on life history

Historical information shows that Sigmodontinae are irrelevant hosts for South American ticks of the genera Haemaphysalis Koch, Rhipicephalus Koch and Dermacentor Koch. Nine Amblyomma Koch species were found on Sigmodontinae but only Amblyomma triste Koch, 1844 appears strongly related to them. Eighteen species of Ixodes Latreille were determined on these hosts. Four species sporadically infest Sigmodontinae; eight are found mostly on Sigmodontinae but the records are too few for any inference. Six: I. amarali Fonseca, 1935, I. longiscutatus Boero, 1944, I. loricatus Neumann, 1899, I. luciae Sénevet, 1940, Ixodes sigelos Keirans, Clifford and Corwin, 1976 and I. venezuelensis Kohls, 1953 are usual parasites of Sigmodontinae. It is proposed that the Ixodes-Sigmodontinae relationship evolved from a South American tick ancestor parasite of Didelphidae. Their descendants are two extant clades, one formed by I. loricatus-I. luciae defined by analysis of 16S rDNA sequences further including I. amarali and I. schulzei by morphological affinities. These species (I. schulzei excluded) have adult ticks feeding on Didelphidae and sub-adult ticks feeding on Didelphidae and several species from five sigmodontin tribes. The second clade is formed by I. abrocomae Lahille, 1916 (known from few specimens, mostly collected from Sigmodontinae), I. sigelos (mainly a parasite of Sigmodontinae), I. stilesi Neumann, 1911 (parasite of deer), and possibly I. taglei Kohls, 1969 (parasite of deer) by morphological affinity. This clade is related to I. neuquenensis Ringuelet, 1947, an exclusive parasite of Dromiciops gliroides Thomas (Microbiotheriidae Ameghino).Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Nava, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentin

Hosts of Amblyomma dissimile Koch, 1844 and Amblyomma rotundatum Koch,1844 (Acari: Ixodidae)

Host records of Amblyomma dissimile Koch, 1844 and Amblyomma rotundatum Koch, 1844 from the literature were critically reviewed. A total of 417 records on 101 species of tetrapods, and 193 records in 74 species of tetrapods were determined for A. dissimile and A. rotundatum, respectively. Aves have been found only once infested with A. dissimile. This tick has been detected on four species of Bufonidae, while A. rotundatum has been recorded on 13 species from six families of Anura. Crocodilia has been recorded infested by A. rotundatum (captive host, one species) and A. dissimile (two species). Sixteen species of Mammalia from ten families and eight species from eight families have been found infested with A. dissimile and A. rotundatum, including humans, respectively. A total of 63 species of Squamata (10 families) were found infested with A. dissimile, while the corresponding numbers for A. rotundatum are 45 species in nine families. A total of 15 species of Testudines (four families) and nine species (three families) have been found infested with A. dissimile and A. rotundatum, respectively. When infestation on captive and laboratory hosts were excluded from the analysis the number of species naturally infested with A. dissimile diminished to 88 and 58 for A. rotundatum. However, natural hosts infested with larvae, nymphs and adults of A. dissimile are Bufo marinus (Linnaeus), Bufo peltocephalus Tschudi, Proechimys semispinosus (Tomes), Boa constrictor Linnaeus, Epicrates striatus (Fischer), Oxybelis aeneus (Wagler), Cyclura cychlura (Cuvier), Iguana iguana (Linnaeus), Tupinambis teguixin (Linnaeus) and Trachemys scripta (Thunberg), but the commonest hosts harbouring all parasitic stages are B. marinus, B. constrictor and /. iguana. Hosts for all parasitic stages of A. rotundatum are B. marinus, Bufo schneiden Werner and B. constrictor, although records on B. marinus are considerably higher than the records on the other two hosts. The contribution of sheep and Hydrochoerus hydrochaeris (Linnaeus) as hosts of A. dissimile, and Dasypus novemcinctus Linnaeus as host of A. rotundatum, were overestimated in previous studies. The ample host-range of these tick species may partly explain their wide distribution from southern U.S.A. to northern Argentina, but there are also chances that more than one species are represented under the names A. dissimile and A. rotundatum.Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Hosts of Amblyomma dissimile Koch, 1844 and Amblyomma rotundatum Koch,1844 (Acari: Ixodidae)

Host records of Amblyomma dissimile Koch, 1844 and Amblyomma rotundatum Koch, 1844 from the literature were critically reviewed. A total of 417 records on 101 species of tetrapods, and 193 records in 74 species of tetrapods were determined for A. dissimile and A. rotundatum, respectively. Aves have been found only once infested with A. dissimile. This tick has been detected on four species of Bufonidae, while A. rotundatum has been recorded on 13 species from six families of Anura. Crocodilia has been recorded infested by A. rotundatum (captive host, one species) and A. dissimile (two species). Sixteen species of Mammalia from ten families and eight species from eight families have been found infested with A. dissimile and A. rotundatum, including humans, respectively. A total of 63 species of Squamata (10 families) were found infested with A. dissimile, while the corresponding numbers for A. rotundatum are 45 species in nine families. A total of 15 species of Testudines (four families) and nine species (three families) have been found infested with A. dissimile and A. rotundatum, respectively. When infestation on captive and laboratory hosts were excluded from the analysis the number of species naturally infested with A. dissimile diminished to 88 and 58 for A. rotundatum. However, natural hosts infested with larvae, nymphs and adults of A. dissimile are Bufo marinus (Linnaeus), Bufo peltocephalus Tschudi, Proechimys semispinosus (Tomes), Boa constrictor Linnaeus, Epicrates striatus (Fischer), Oxybelis aeneus (Wagler), Cyclura cychlura (Cuvier), Iguana iguana (Linnaeus), Tupinambis teguixin (Linnaeus) and Trachemys scripta (Thunberg), but the commonest hosts harbouring all parasitic stages are B. marinus, B. constrictor and /. iguana. Hosts for all parasitic stages of A. rotundatum are B. marinus, Bufo schneiden Werner and B. constrictor, although records on B. marinus are considerably higher than the records on the other two hosts. The contribution of sheep and Hydrochoerus hydrochaeris (Linnaeus) as hosts of A. dissimile, and Dasypus novemcinctus Linnaeus as host of A. rotundatum, were overestimated in previous studies. The ample host-range of these tick species may partly explain their wide distribution from southern U.S.A. to northern Argentina, but there are also chances that more than one species are represented under the names A. dissimile and A. rotundatum.Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Birds and hard ticks (Acari: Ixodidae), with discussions about hypotheses on tick evolution

The relationship between birds (Aves) and hard ticks (Ixodidae) was analyzed for the 386 of 721 tick extant species whose larva, nymph and adults are known as well as their natural hosts. A total of 136 (54 Prostriata= Ixodes, 82 Metastriata= all other genera) are frequently found on Aves, but only 32 species (1 associated with Palaeognathae, 31 with Neognathae) have all parasitic stages feeding on birds: 25 Ixodes (19% of the species analyzed for this genus), 6 Haemaphysalis (7%) and 1 species of Amblyomma (2%). The species of Amblyomma feeds on marine birds (MB), the six Haemaphysalis are parasites of non-marine birds (NMB), and 14 of the 25 Ixodes feed on NMB, one feeds on NMB and MB, and ten on MB. The Australasian Ixodes + I. uriae clade probably originated at an uncertain time from the late Triassic to the early Cretaceous. It is speculated that Prostriata first hosts were Gondwanan theropod dinosaurs in an undetermined place before Pangaea break up; alternatively, if ancestral monotromes were involved in its evolution an Australasian origin of Prostriata seems plausible. As for Prostriata the Motherland of Ixodida is probably Gondwana.Aves y garrapatas duras (Ixodidae), con discusión sobre hipótesis sobre evolución de las garrapatas. En esta revisión se analizó la relación entre aves y garrapatas duras (Ixodidae) para las 386 de 725 especies de garrapatas que utilizan aves como hospedadores para larvas, ninfas y adultos. Un total de 136 especies (54 Prostriata= Ixodes, 82 Metastriata= restantes géneros) son frecuentemente encontradas sobre aves, pero solo 32 especies (1 asociada con Palaeognathae, 31 con Neognathae) tienen ciclos donde todos los estadios se alimentan sobre aves: 25 Ixodes (19% de las especies analizadas para este género), 6 Haemaphysalis (7% del total) y 1 especie de Amblyomma (2% del total). Las especies de Amblyomma se alimentan sobre aves marinas (MB), las seis de Haemaphysalis son parásitas de aves no-marinas (NMB), y 14 de las 25 especies de Ixodes se alimentan sobre NMB, una sobre NMB y MB, y diez sobre MB. El clado de Australasia Ixodes + I. uriae probablemente se originó entre el fin del Triásico y comienzos del Cretácico. Se especula que los primeros hospedadores de Prostriata fueron dinosaurios terópodos con distribución Gondwánica; alternativamente, si monotremas ancestrales estuvieron involucrados en su evolución, un origen de Prostriata en Australasia es plausible. Al igual que para Prostriata, el área de origen de Ixodida es probablemente GondwanaEEA RafaelaFil: Guglielmone, Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Ornithodoros quilinensis sp. nov. (Acari, Argasidae), a new tick species from the Chacoan region in Argentina

Ornithodoros quilinensis sp. nov. (Acari: Argasidae) is described from larvae collected on the small rodents Graomys centralis (Cricetidae: Sigmodontinae) in Argentina. The diagnostic characters for this new species are a combination of small size (520-540 μm), a dorsal plate oval in shape with a length of approximately 200 μm, 14 pairs of dorsal setae, hypostome short and narrower at the base (length from Ph1 to apex 133 μm (120-141)) with dental formula 2/2 and apex blunt, and the capsule of the Haller's organ irregular in shape and without reticulations. The analysis of the 16S rDNA sequences available for the genus Ornithodoros indicate that, phylogenetically, O. quilinensis represents an independent lineage only related to a Bolivian tick species of the genus Ornithodoros yet not formally described.Fil: Venzal, José M.. Universidad de la Republica, Salto; UruguayFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Mastropaolo, Mariano. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Casás, Gustavo. UNIVERSIDAD DE LA REPUBLICA (UDELAR); . Universidad de la República; UruguayFil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; Argentin

Ticks of new world tapirs

In this paper, we present an updated list of ticks that have been found infesting New World tapirs. For this purpose, literature records were obtained from the INTA tick database. Data are presented according to tick species, tapir species, and country. A total of 27 tick species have been reported infesting New World tapirs. Most of the reports were on T. terrestris (20 tick species in 10 countries). Thirteen tick species were reported on T. bairdii in 3 countries, and only 2 tick species on T. pinchaque in 2 countries. Ticks reported on tapirs comprised 18 species of the genus Amblyomma, and 7 other species representing the genera Ixodes, Haemaphysalis, Dermacentor, and Rhipicephalus from the Ixodidae family, and at least 2 Ornithodoros species from the Argasidae family. Indeed, tapirs are very significant hosts for the Neotropical tick fauna. Since tapirs are usually found in less fragmented biomes with high biodiversity, and the richness of tick species is higher in tapirs than any other Neotropical vertebrate species, further studies are needed to evaluate the role of tapir-associated ticks on biodiversity. The role of these ticks on tick-borne diseases for tapir and other vertebrates also needs further investigations