Vector potential and population dynamics for Amblyomma inornatum

Abstract

We studied the natural life cycle of Amblyomma inornatum and its vector potential in South Texas. This tick is distributed throughout South Texas and most of Central America. A. inornatum represented 1.91% of the ticks collected by carbon dioxide traps during a study of free-living ticks in the Tamaulipan Biotic Province in South Texas. The life cycle of A. inornatum in South Texas showed a clear seasonal pattern consistent with one generation per year. Nymphs emerged in the spring with a peak in February through May. Adults emerged in the summer with a peak in July through September. Detection of A. inornatum larvae was negatively correlated with saturation deficit and positively correlated with rain in the previous few months. Adult activity was positively correlated with temperature and rain in the previous five weeks. Using PCR we detected the presence of species related to Candidatus Borrelia lonestari, Borrelia burgdorferi, Rickettsia species (Candidatus Rickettsia amblyommii), Ehrlichia chaffeensis, and another Ehrlichia related to Ehrlichia ewingii. Finally we sequenced the mitochondrial 16S rRNA genes and found that A. inornatum is most closely related to Amblyomma parvum. This is the first report of the life cycle, vector potential and phylogeny of A. inornatum.

Detection of rickettsiae in fleas and ticks from areas of Costa Rica with history of spotted fever group rickettsioses

“…An analysis of the mitochondrial 16S ribosomal RNA gene from this tick determined that the highest partial sequence homology (99.3%; 400/403) was with a sequence of A. mixtum form Texas, USA (Accession No. KM458242) (Medlin et al, 2015). The second sample that was positive for R. rickettsii was a single nymph of Amblyomma collected near the metropolitan area of San José.…”

Presence of Babesia odocoilei and Borrelia burgdorferi Sensu Stricto in a Tick and Dual Parasitism of Amblyomma inornatum and Ixodes scapularis on a Bird in Canada

“…In their indigenous distribution, A. inornatum nymphs have peak questing activity from February through May [30]. This host-seeking activity period corresponds with the northbound migration of Veeries en route through Central America.…”

“…Amblyomma inornatum parasitizes a wide range of vertebrate hosts including Bovidae (e.g., sheep, goats, cattle), Cervidae (e.g., deer, elk), Dasypodidae (e.g., armadillo), Tayassuidae (e.g., peccary), Cricetidae (e.g., hispid cotton rats), Sciuridae (e.g., ground squirrels), Leporidae (e.g., rabbits, hares), Equidae (e.g., horses), Didelphidae (e.g., opossum), Felidae (e.g., cats), and Canidae (e.g., coyotes, dogs) [26,27,28,29,30]. This Amblyomma tick also parasitizes Galliformes (e.g., pheasants) and Passeriformes (perching birds, such as Veeries).…”

“…This Amblyomma tick also parasitizes Galliformes (e.g., pheasants) and Passeriformes (perching birds, such as Veeries). From a medical standpoint, Medlin et al state that A. inornatum bites humans [30].…”

Molecular identification of Ehrlichia ewingii in a polyarthritic Texas dog

“…Recently, the tick species A inornatum has also been identified as infected with E ewingii , though further studies would need to be conducted to definitively prove the vector competency of the tick species. In Texas, both species of opportunistic feeding ticks have been identified harboring E ewingii . It has been accepted that E ewingii is a zoonotic pathogen initially recognized as a distinct etiologic agent of dogs in 1992 and later of humans in 1999.…”