Amblyomma Koch 1844

Life cycle of three-host ixodid (hard) ticks.The adult of a three-host ixodid (hard) tick is considered the diagnostic stage, as identification to the species level is best achieved with adults. Most ticks of public health importance are three-host ticks, including members of the genera Ixodes (Lyme borreliosis, babesiosis, human granulocytic ehrlichiosis), Amblyomma (tularemia, ehrlichiosis and Rocky Mountain spotted fever), Dermacentor (Rocky Mountain spotted fever, Colorado tick fever, tularemia, tick paralysis), and Rhipicephalus (Rocky Mountain spotted fever, boutonneuse fever).Three-host ixodid ticks have a life cycle that usually spans three years, although some species can complete the cycle in just two years. After feeding, adult females drop off the third host to lay eggs (1), usually in the fall. Eggs hatch into six-legged larvae (2) and overwinter in the larval stage. In the spring, the larvae seek out and attach to the first host, usually a small rodent (3). Later in the summer, engorged larvae leave the first host (4) and molt into nymphs (5), usually in the fall. The ticks overwinter in this stage. During the following spring, the nymphs seek out and attach to the second host (6), usually another rodent (e.g., a mouse) or lagomorph (e.g., a rabbit). The nymphs feed on the second host and drop off later in the summer (7). Nymphs molt into adults (7a-7b) off the host in the late summer or fall, and overwinter in this stage. The next spring, adults seek out and attach to a third host, which is usually a larger herbivore (including cervids and bovids), carnivore, or human (8). The adults feed and mate on the third host during the summer. Females drop off the host in the fall to continue the cycle. Females may reattach and feed multiple times. The three hosts do not necessarily have to be different species, or even different individuals. Humans may serve as first, second or third hosts.From Centers for Disease Control Parasites and Health website.

This photograph depicts a dorsal view of a male Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

This 2008 photograph depicts a dorsal view of a male yellow dog tick, Amblyomma aureolatum, which is a vector of Rocky Mountain spotted fever (RMSF) in the country of Brazil.Note that the back of this tick is completely covered by his hard, scutum, or shield. However, when this feature is compared with that of the female counterpart of this Ixodidae hard tick, PHIL 11069, you’ll note that the female’s dorsal abdomen is only partially covered, which allows her abdomen to greatly expand when she is ingesting her blood meal.Created: 2008

This photograph depicts a dorsal view of a male Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

This 2008 photograph depicts a dorsal view of a female yellow dog tick, Amblyomma aureolatum, which is a vector of Rocky Mountain spotted fever (RMSF) in the country of Brazil.Note that the back of this tick is only partially covered by her hard, scutum, or shield, which allows her abdomen to expand to many times the size seen here. Compare this feature with that of the male counterpart of this Ixodidae hard tick, PHIL 11070, and observe how the male's scutum covers his entire dorsal abdomen.Created: 2008

This photograph depicts a dorsal view of a female Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

Using a pin as a reference tool, this photograph depicts a dorsal view of four Amblyomma maculatum ticks. From left to right, this group of four included a larval tick, a nymph, an adult male, and at far right, an adult female. Note that the head of the pin measures just under 2mm in diameter, while its full length measures 22mm.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo. Each life stage depicted here, can feed on human hosts, and can be infected with Rickettsia parkeri.Created: 2008

This photograph depicts a dorsal view of a female Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

This photograph depicts a dorsal view of a male Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

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 depicts a dorsal view of a male Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

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 a female Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).Note the large scutum, or shield, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen. See PHIL 10870 and 10871, for an image depicting a dorsal view of a female A. cajennense tick. Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.Created: 2008

This photograph depicts a dorsal view of a female Gulf Coast tick, Amblyomma maculatum.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo.Created: 2008

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).Note the large scutum, or shield, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen. See PHIL 10870 and 10871, for an image depicting a dorsal view of a female A. cajennense tick. Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.Created: 2008

Using a pin as a reference tool, this photograph depicts a dorsal view of four Amblyomma maculatum ticks. From left to right, this group of four included a larval tick, a nymph, an adult male, and at far right, an adult female. Note that the head of the pin measures just under 2mm in diameter, while its full length measures 22mm.This tick specie is a known vector for Rickettsial organisms, Rickettsia parkeri, and Ehrlichia ruminantium, formerly Cowdria ruminantium. R. parkeri is a member of the spotted fever group of rickettsial diseases affecting humans, while E. ruminantium causes heartwater disease, an infectious, noncontagious, tick-borne disease of domestic and wild ruminants, including cattle, sheep, goats, antelope, and buffalo. Each life stage depicted here, can feed on human hosts, and can be infected with Rickettsia parkeri.Created: 2008

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).Note the large scutum, or shield, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen. See PHIL 10870 and 10871, for an image depicting a dorsal view of a female A. cajennense tick. Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.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 depicts a dorsal view of a female cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF). Note the small scutum, or shield, which unlike its male counterpart, covers only a small region of this specimen’s dorsal abdomen, just caudad to it head and elongated mouthparts. See PHIL 10872 for an image depicting a dorsal view of a male A. cajennense tick.Created: 2008

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 cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF). Note the small scutum, or shield, which unlike its male counterpart, covers only a small region of this specimen’s dorsal abdomen, just caudad to it head, and elongated mouthparts. See PHIL 10872 for an image depicting a dorsal view of a male A. cajennense tick.Created: 2008

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

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).Note the large scutum, or shield, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen. See PHIL 10870 and 10871, for an image depicting a dorsal view of a female A. cajennense tick. Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.Created: 2008