Amblyomma americanum, or lone star tick, is a species of tick

Tick

Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

 in the genus Amblyomma

Amblyomma

Amblyomma is a genus of hard ticks. Some are disease vectors, for example for Rocky Mountain spotted fever in Brazil or ehrlichiosis and anaplasmosis in the USA....

. It's average length is 1/4 inch.

Distribution

It is very widespread in the United States ranging from Texas to Iowa in the Midwest and east to the coast where it can be found as far north as Maine. It is most common in wooded areas, particularly in forests with thick underbrush.

Vector

Like all ticks, it can be a vector of diseases including human monocytotropic ehrlichiosis (Ehrlichia chaffeensis

Ehrlichia chaffeensis

Ehrlichia chaffeensis is a species of rickettsiales bacteria.It is named for Fort Chaffee.It is the causative agent of human monocytic ehrlichiosis....

), canine and human granulocytic ehrlichiosis (Ehrlichia ewingii

Ehrlichia ewingii

Ehrlichia ewingii is a species of rickettsiales bacteria.Previously known to infect dogs, it has recently been associated with human infection .There is currently no serological test.PCR can be used in diagnosis....

), tularemia (Francisella tularensis

Francisella tularensis

Francisella tularensis is a pathogenic species of gram-negative bacteria and the causative agent of tularemia or rabbit fever. It is a facultative intracellular bacterium....

), and Southern tick-associated rash illness

Southern tick-associated rash illness

Southern tick-associated rash illness or Masters' disease is an emerging infectious disease related to Lyme disease that occurs in southeastern and south-central United States. It is spread by tick bites, but the organism that causes the infection is unknown.-Causes:This illness is a tick-borne...

 (STARI, possibly caused by the spirochete Borrelia lonestari). STARI exhibits a rash similar to that caused by Lyme disease

Lyme disease

Lyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...

 but is generally considered to be less severe.

Though the bacteria responsible for Lyme disease, Borrelia burgdorferi

Borrelia burgdorferi

Borrelia burgdorferi is a species of Gram negative bacteria of the spirochete class of the genus Borrelia. B. burgdorferi is predominant in North America, but also exists in Europe, and is the agent of Lyme disease....

, has occasionally been isolated from lone star ticks, numerous vector competency tests have demonstrated that this tick is extremely unlikely to be capable of transmitting Lyme disease. There is evidence that the A. americanum saliva inactivates Borrelia burgdorferi more quickly than the saliva of Ixodes scapularis

Ixodes scapularis

Ixodes scapularis is commonly known as the deer tick or blacklegged tick , and in some parts of the USA as the bear tick. It is a hard-bodied tick of the eastern and northern Midwestern United States...

.

External links

• http://www.k-state.edu/parasitology/625tutorials/Tick03.html