Ticks are prevalent in Missouri and can transmit various diseases, posing health risks to people and pets. Understanding the types of ticks found in the state and the pathogens they carry is important for recognizing potential exposures and guiding timely medical attention if a bite occurs.
Most Prevalent Tick Species
The American dog tick, Dermacentor variabilis, is one of Missouri’s most commonly encountered ticks. It has a reddish-brown body with whitish or grayish markings; the female’s scutum covers about one-third of her body, while the male’s markings are more diffuse. These ticks are frequently found in grassy fields, along trails, and in wooded areas, with peak activity from mid-April through early September. This tick is a known carrier of Rocky Mountain Spotted Fever, tularemia, and can also cause tick paralysis.
The Lone Star tick, Amblyomma americanum, is easily recognized by the distinctive white or silvery spot on the back of the adult female. These aggressive feeders are widespread throughout Missouri, inhabiting wooded and brushy environments, and are particularly active from April through July. Lone Star ticks can transmit Southern Tick-Associated Rash Illness (STARI), ehrlichiosis, tularemia, Heartland virus, Bourbon virus, and alpha-gal syndrome, which can cause an allergy to red meat.
The Blacklegged tick, Ixodes scapularis, also known as the deer tick, is considerably smaller than other common ticks, often described as being about the size of a sesame seed. It is characterized by its dark legs and overall black coloration on the upper body. These ticks are increasingly common in Missouri, preferring wooded and brushy habitats, and are active during the spring and fall. This tick is a primary vector for Lyme disease, and can also transmit anaplasmosis, babesiosis, and Powassan virus.
Less Common and Emerging Tick Species
The Gulf Coast tick, Amblyomma maculatum, is identified by its ornate markings, with males featuring web-like white lines and females displaying bright white markings on their dorsal shield. While historically more prevalent in coastal regions, these ticks are newcomers to Missouri. They typically inhabit grass prairies and coastal uplands. This tick is associated with Rickettsia parkeri rickettsiosis, a form of spotted fever, and can also cause tick paralysis.
The Brown dog tick, Rhipicephalus sanguineus, is a reddish-brown tick with an elongated body. Unlike most other tick species, it can complete its entire life cycle indoors, making it unique for infesting homes and kennels. While primarily feeding on dogs and occasionally cats, these ticks can be brought into homes by pets. Though less common in humans, this tick can transmit Rocky Mountain Spotted Fever to dogs, and has been associated with canine ehrlichiosis and babesiosis.
An emerging concern in Missouri is the Asian longhorned tick, Haemaphysalis longicornis, an invasive species first identified in the state in July 2021. Unfed, these ticks are light reddish-tan to dark reddish with brown markings, while engorged females can swell to the size of a pea. A defining characteristic of this tick is its ability to reproduce asexually through parthenogenesis, where a single female can lay thousands of eggs without mating. This tick can infest a wide range of hosts, including livestock, wildlife, humans, and pets, and large infestations can lead to severe blood loss in animals.
Key Characteristics for Identification
Identifying various tick species involves observing several key characteristics, including overall size, body coloration, and specific markings. Additionally, observing the length and shape of a tick’s mouthparts can provide further clues for identification. When engorged with blood, many tick species, particularly females, can swell significantly and change color, often appearing gray. Larval ticks possess six legs, while nymphs and adults have eight.
Why Knowing Missouri Ticks Matters
Understanding the different tick species in Missouri is important for assessing potential health risks after a bite. Each tick species can carry specific pathogens, meaning proper identification helps connect the tick to the diseases it may transmit. Knowing which diseases are associated with which ticks allows for increased awareness of symptoms, prompting timely medical consultation if an illness develops. This knowledge also contributes to informed decisions regarding outdoor activities, as different tick species prefer distinct habitats, influencing precautions taken before entering such areas. Ultimately, understanding the types of ticks present in Missouri reinforces the importance of vigilance and proactive steps to protect oneself and others from tick-borne illnesses.