Ixodoidea

This photograph depicts a dorsal view of a male Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.See PHIL 10869, for a side-by-side comparative view of both a male and female D. andersoni tick.Created: 2008

This photograph depicts a dorsal view of a female Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.Dermacentor andersoni is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for completion. Adult wood ticks feed primarily on large mammals, while the larvae and nymphs feed on small rodents. See PHIL 10869, for a side-by-side comparative view of both a male and female D. andersoni tick.Created: 2008

This photograph depicts a dorsal view of a female Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.Dermacentor andersoni is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for completion. Adult wood ticks feed primarily on large mammals, while the larvae and nymphs feed on small rodents. See PHIL 10869, for a side-by-side comparative view of both a male and female D. andersoni tick.Created: 2008

This photograph depicts a dorsal view of both a female (Lt), and male (Rt) Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever. Note the smaller size of the female’s scutum compared to the male’s larger scutum. From the Latin word for shield, the scutum, i.e., dorsal shield, covers only a small part of the female’s dorsal surface, thereby, enabling her abdomen to expand, becoming engorged during feeding. The male’s scutum covers his entire dorsal surface, and is mottled with brown markings overall, while the female’s small scutum sports an almost entirely a cream-colored gray surface.Created: 2008

This photograph depicts a dorsal view of a male Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.See PHIL 10869, for a side-by-side comparative view of both a male and female D. andersoni tick.Created: 2008

This photograph depicts a dorsal view of a female Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.Dermacentor andersoni is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for completion. Adult wood ticks feed primarily on large mammals, while the larvae and nymphs feed on small rodents. See PHIL 10869, for a side-by-side comparative view of both a male and female D. andersoni tick.Created: 2008

This photograph depicts a dorsal view of a female Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.Dermacentor andersoni is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for completion. Adult wood ticks feed primarily on large mammals, while the larvae and nymphs feed on small rodents. See PHIL 10869, for a side-by-side comparative view of both a male and female D. andersoni tick.Created: 2008

This photograph depicted a dorsal view of an immature, or nymphal, "lone star tick", Amblyomma americanum. Nymphal ticks are much smaller than adult ticks, and people might not notice a nymph until it has been feeding for a few days. Nymphs are, therefore, more likely than adult ticks to transmit diseases to people.Created: 2006

This photograph depicted a dorsal view of a male "lone star tick", Amblyomma americanum.Created: 2006

This photograph depicted a dorsal view of a male "lone star tick", Amblyomma americanum.Created: 2006

This photograph depicts a dorsal view of a female "lone star tick", Amblyomma americanum. Note the characteristic lone star marking located centrally on its dorsal surface, at the distal tip of its scutum. To view additional images related to this tick specie, see PHIL 4407, 8676 through 8682, 8684, and 8685.Created: 2006

This photograph depicted a dorsal view of a female "lone star tick", Amblyomma americanum. Note the characteristic lone star marking located centrally on its dorsal surface, at the distal tip of its scutum. To view additional images related to this tick specie, see PHIL 4407, 8676 through 8681, and 8683 through 8685.Created: 2006

This photograph depicts an anterior, or head-on view of an engorged female "lone star tick", Amblyomma americanum. Note a number of round, amber-colored eggs that after just having been laid, became attached to the anterior abdomen adjacent to the female’s scutum. To view additional images related to this tick specie, see PHIL 4407, 8676 through 8680, and 8682 through 8685.Created: 2006

This photograph depicted ventral view of an engorged female "lone star tick" Amblyomma americanum. An Ixodes or "hard" tick, A. americanum is found through the southeast and south-central states, and has been shown to transmit the spirochete, Borrelia lonestari, the pathogen responsible for causing a Lyme disease-like rash known as "Southern tick-associated rash illness" (STARI). Representatives from all three of its life stages aggressively bite people in the southern U.S.Created: 2006

This photograph depicts a dorsal view of an engorged female "lone star tick", Amblyomma americanum. Note a number of round, amber-colored eggs showing from beneath the head region, which were just laid by this female. An engorged female of this species can lay approximately 2000-2500 eggs. To view additional images related to this tick specie, see PHIL 4407, 8676, 8677, 8678, and 8680 through 8685.Created: 2006

This photograph depicts a dorsal view of an engorged female "lone star tick", Amblyomma americanum. Note a number of round, amber-colored eggs showing from beneath the head region, which were just laid by this female. An engorged female of this species can lay approximately 2000-2500 eggs. To view additional images related to this tick specie, see PHIL 4407, 8676, 8677, and 8679 through 8685.Created: 2006

This photograph depicts a dorsal view of an engorged female lone star tick, Amblyomma americanum. An ixodid or hard tick, A. americanum is found through the eastern and south-central states and can transmit disease agents that affect humans, dogs, goats, and white-tailed deer. Representatives from all three of its life stages aggressively bite people in the southern U.S. Lone star ticks transmit Ehrlichia chaffeensis and Ehrlichia ewingii, both of which cause disease. Borrelia lonestari, a pathogen associated with Southern tick-associated associated rash illness (STARI), also infects lone star ticks. Research suggests that up to 10% of the lone star ticks in an endemic area can be infected with any one of these pathogens. These ticks also are infected with a spotted-fever group Rickettsia, Rickettsia amblyommii but it is unknown at this time if this bacterium causes disease.Created: 2006

This photograph depicts a dorsal view of a female lone star tick, Amblyomma americanum. An ixodid or hard tick, A. americanum is found through the eastern and south-central states and can transmit disease agents that affect humans, dogs, goats, and white-tailed deer. Representatives from all three of its life stages aggressively bite people in the southern U.S. Lone star ticks transmit Ehrlichia chaffeensis and Ehrlichia ewingii, both of which cause disease. Borrelia lonestari, a pathogen associated with Southern tick-associated associated rash illness (STARI), also infects lone star ticks. Research suggests that up to 10% of the lone star ticks in an endemic area can be infected with any one of these pathogens. These ticks also are infected with a spotted-fever group Rickettsia, Rickettsia amblyommii but it is unknown at this time if this bacterium causes disease.Created: 2006

This photograph depicted a dorsal view of an immature, or nymphal, "lone star tick", Amblyomma americanum. Nymphal ticks are much smaller than adult ticks, and people might not notice a nymph until it has been feeding for a few days. Nymphs are, therefore, more likely than adult ticks to transmit diseases to people.Created: 2006

This photograph depicted a dorsal view of a male "lone star tick", Amblyomma americanum.Created: 2006

This photograph depicted a dorsal view of a male "lone star tick", Amblyomma americanum.Created: 2006

This photograph depicts a dorsal view of a female "lone star tick", Amblyomma americanum. Note the characteristic lone star marking located centrally on its dorsal surface, at the distal tip of its scutum. To view additional images related to this tick specie, see PHIL 4407, 8676 through 8682, 8684, and 8685.Created: 2006

This photograph depicted a dorsal view of a female "lone star tick", Amblyomma americanum. Note the characteristic lone star marking located centrally on its dorsal surface, at the distal tip of its scutum. To view additional images related to this tick specie, see PHIL 4407, 8676 through 8681, and 8683 through 8685.Created: 2006

This photograph depicted ventral view of an engorged female "lone star tick" Amblyomma americanum. An Ixodes or "hard" tick, A. americanum is found through the southeast and south-central states, and has been shown to transmit the spirochete, Borrelia lonestari, the pathogen responsible for causing a Lyme disease-like rash known as "Southern tick-associated rash illness" (STARI). Representatives from all three of its life stages aggressively bite people in the southern U.S.Created: 2006