Ornithodorostalaje (Guèrin-Méneville, 1849) Neumann, 1911
(Figure 5-1)
ETYMOLOGY: Ornitho = bird and doros = leather bag; along with talaje for
SYNONYMS:Argastalaje Guèrin-Méneville, 1849; Alectorobiustalaje (Guèrin-Méneville, 1849) Pocock, 1907.
HISTORY:Ornithodorus talaje was originally described by Guèrin-Méneville in 1849 for ticks collected from Guatemala.
GEOGRAPHIC DISTRIBUTION: The range of Ornithodorustalaje extends from California and Kansas to Argentina. In the United States, it is known from California, Arizona, Nevada, Kansas, Texas, and Florida. This tick has been reported from the "hot country" of Mexico and has been found on the Peninsula of Yucatan, Campeche, Tabasco, Chiapas, the Isthmus and State of Vera Cruz, extending along the Gulf Coast toward Texas; on the Pacific Coast the species has not been found except to the north in the region of the Isthmus (Cooley and Kohls, 1944). Ornithodorustalaje is also widely distributed in Panama (Dunn, 1933).
LOCATION IN HOST: Of 100 Panamanian cats, 26 were infested with Ornithodorustalaje. The specific collection site in the feline haircoat was not noted (Dunn, 1933). Tiny argasid larvae may localize on the cat’s body, head, and neck. Nymphs and adults are often found in the host's environment (Hoskins and Cupp, 1988).
IDENTIFICATION: In members of the genus Ornithodorus, the capitulum is either subterminal or distant from the anterior margin; the hypostome is well developed, essentially similar in both adult male and female soft ticks (Fig. 5-01) and in the nymphal stages . The integument has discs and mamillae which blend in a wide variety of patterns. This integumental pattern is continuous over the sides from dorsal to ventral surfaces. Dorsal humps and subapical dorsal protuberances on the legs are progressively more prominent in successive nymphal stages. The body is more or less flattened but strongly convex dorsally when distended. In Ornithodorustalaje, cheeks (the paired flaps at the sides of the camerostome) are present (Hoskins and Cupp, 1988). The hood (the anterior projection of the integument) is present but small. The camerostome (the cavity in which the capitulum is located) is indefinite and obscured by the large cheeks (Cooley and Kohls, 1944). The genus Ornithodorus includes 100 species in eight subgenera (Hoogstraal, 1985). Cooley and Kohls (1944) provide detailed descriptions of the adult and larval stages of Ornithodorustalaje.
LIFE CYCLE: There are four developmental stages in the life cycle of Ornithodorustalaje: egg, larva, nymph, and adult male and female (Hoskins and Cupp, 1988). This tick has been collected from a wide variety of hosts. In the United States, it has been found only on wild rodents or in association with them. In Mexico, natural hosts are small, wild rodents and other mammals that inhabit underground nests (Cooley and Kohls, 1944). Mating occurs off host and is facilitated by phermones. Reception of the pheromone is handled by sensillae on palps located lateral to the mouthparts. These phermones acts to assemble members of the population. All stages respond, however males respond to females more vigorously than females respond to males. Adults feed and mate several times. Females oviposit several times (Hoskins and Cupp, 1988).
CLINICAL PRESENTATION AND PATHOGENESIS: Of 100 cats examined by Dunn (1933) in Panama, 26 were infested with primarily the larval stage of Ornithodorustalaje. A second-stage nymph was found on one cat. This author attributed no clinical signs in the infested cats, although the bite of Ornithodorustalaje has been reported to be painful (Harwood and James, 1979).
DIAGNOSIS: This tick is best diagnosed by identification of its unique morphologic characteristics. Credible criteria for identifying Ornithodorustalaje are now determined by trained entomologists. Blood tubes or screw-cap vials containing 70% isopropyl alcohol are used for preserving collected stages. A definitive diagnosis is usually performed by an area, state, or federal veterinarian, local cooperative extension service, or universities with a school of veterinary medicine or a department of entomology (Hoskins and Cupp, 1988).
TREATMENT: Any of the popular acaricides used for treating infestation of hard ticks on cats, should prove effective in treating Ornithodorus talaje.
EPIZOOTIOLOGY: This tick is usually diagnosed in cats who are allowed to roam freely. The tick is seldom observed in dwellings, so it is rarely found in house cats (Cooley and Kohls, 1944).
HAZARDS TO OTHER ANIMALS: This species has been collected from a wide variety of hosts throughout the Americas. In the United States, it has been found only on wild rodents or in association with them. In Mexico, the natural hosts are small, wild rodents and probably other mammals that inhabit subterranean nests (Cooley and Kohls, 1944). Among the hosts in Panama listed by Dunn (1933) were man, several species of mice, several species of monkeys, dogs, chickens, opossums and a snake.
HAZARDS TO HUMANS: This tick is a vector of Mexican-American relapsing fever of humans (Hoskins and Cupp, 1988).
CONTROL/PREVENTION: Accurate identification of soft ticks from the parasitized host or from the environment is a prerequisite to their control (Hoskins and Cupp, 1988). The cat's ability to roam freely to areas frequented by rats and mice (alleys, deserted lots, etc.) should be restricted. Rodent control should also prove effective (Harwood and James, 1979).
REFERENCES
Cooley RA, Kohls GM. 1944. The Argasidae of North America, Central America and Cuba, Monograph 1. Am Midl Nat. 37-117, 142.
Dunn LH. 1933. Observations on the host selection of Ornithodorustalaje Guèrin., in Panama. Am J Trop Med 13:475-483.
Harwood RF, James MT, Jr. 1979. Entomology in Human and Animal Health, 7th ed. New York, NY, Macmillan, 389-391, 400.
Hoogstraal H. 1985. Argasid and Nuttalliellid ticks as parasites and vectors. Adv Parasitol 24:135-238.
Hoskins JD, Cupp EW. 1988. Ticks of veterinary importance. Part II. The Argasidae family: Identification, behavior, and associated diseases. Comp Cont Ed Prac Vet 10:699-709.
Figure 5-01. Ornithodorus. Ventral view of female tick.