The Gulf Coast Tick
The range of the Gulf Coast tick is historically described as a region approximately 100-150 miles inland along the Gulf of Mexico and southern Atlantic coast, extending from Texas to South Carolina. Resident populations of Gulf Coast ticks are established in Oklahoma, Kansas, and Arkansas, where their distributions appear to be expanding. Incidental introductions of these ticks beyond endemic regions occurs with increasing frequency; likely due to the feeding of immature ticks on migrating birds, and the transportation of tick infested livestock and wildlife into new areas.
A small to medium sized tick, body 3-7 mm long and 2-4 mm wide, with females reaching 18 x 13 mm dimensions at full engorgement. The dorsal area of unfed female ticks is reddish-brown; scutum is longer than wide and ornate, with reddish-brown markings over a pale cream background. Bodies of male Gulf Coast ticks are oval in shape, and pale in color with elongated reddish-brown mottling.
Larvae and nymphs feed on small mammals and ground-frequenting birds including quail, meadowlarks and field sparrows. However, there is increasing evidence indicating that nymphs may also attach to large animals (e.g. cattle), but because of their smaller size and shorter feeding period, may often go unnoticed. Adult ticks attach and feed on cattle, horses, deer, sheep, feral swine, coyotes, dogs, cats, and other carnivores.
Associated Disease Pathogens:
The Gulf Coast tick is an arthropod of increasing medical and veterinary importance. These ticks transmit the pathogen Rickettsia parkeri to humans, a type of spotted fever (rickettsiosis) to humans, Recent studies report infection rates of greater than 20% in Gulf Coast ticks. Gulf Coast ticks are also responsible for transmitting Hepatozoan americanum, a protozoal agent that causes American canine hepatozoonosis in wild and domestic canines in the US. This species has also been shown to experimentally transmit Ehrlichia ruminatium, causal agent of heartwater, a disease fatal to >80% of wild and domestic ruminants.