Wes Watson and Charles Apperson
Ticks are not insects! Class Acarina Order Parasitiformes Family Argasidae soft ticks (5 genera) Family Ixodidae hard ticks (7 genera) Genus Dermacentor 30 species Amblyomma 102 species Ixodes 235 species Rhipicephalus 75 species
Common ticks in North Carolina
Life History of Ticks Four life stages egg, larva, nymph, adult Eggs deposited on ground 100-18,000 eggs Larvae are 6-legged. 2 months Nymphs and adults are 8- legged.
Ticks Need Blood to Survive Ticks have evolved a parasitic relationship with wildlife. All ticks require a blood meal to complete their life cycle. Growth molt from stage to stage Reproduction production of eggs.
Feeding Habits Hbi of Ticks Hard ticks attach for extended periods of time, sometimes days for a single engorgement, and only the female becomes tremendously distended d d by engorgement. Increase their body weight Increase their body weight 168 fold
Larval lone star tick bites leave a dermatitis. The bites are extremely ypruritic. Scratching the bites typically results in development of secondary infections.
Tick bites occasionally result in transmission of pathogens. For Lyme disease, the erythema migrans rash, occurs at the site of the tick bite. Rocky Mountain Spotted Fever The rash occurs on the wrists and ankles and spreads to the trunk of the body.
Pathogens Rickettsial infections: Intracellular bacterium that invades the cells Rocky Mountain Spotted Fever Pathogen invades the cells lining the vascular system Fever, nausea, vomiting, ii headache, h muscle pain Human Monocytic Ehrlichiosis Invades the white blood cells Symptoms same as RMSF Rash occasionally Both Treated with antibiotics
Pathogens Borrelia infections: Spirochete bacterium that invades the skin, nervous system, muscles and joints Stari (Southern tick associated rash illness) Lyme Disease Both Treated with antibiotics
RMSF, HME and Lyme Disease Symptoms appear in 2 14 days RMSF Can be fatal, mortality 11.7% in 30 39 year old age class, mostly males Ehrlichiosis (HME) 5% mortality Ftliti Fatalities occur when there is a lack of known tick exposure, no rash, and gastrointestinal involvement. Lyme Disease is not fatal but is a debilitating disease. Symptoms include rash, arthritis and bells palsy
Why are ticks efficient vectors? Environmentally ytolerant. t. Each stage feeds on a different host. Feed on a variety of wildlife species. Feed for a long period of time. Consume a large volume of blood. Long lived. Often transmit pathogens transovarially (RMSF).
Enzootic Factors of Rocky Mountain Spotted Fever Pathogen: Rickettsia rickettsii, bacterium Vector: Dermacentor variabilis, American Dog Tick Reservoirs Ticks via Transovariol Transmission (TOT) No reduction in virulence in 6 generations In nature only 1 5% of the tick population is infected Rodents, meadow mouse, white footed mouse, cotton rat, ground squirrels, voles Rabbits, oppossum Uninfected tick acquires the infection from high rickettsemia reservoir
Enzootic Factors of Lyme Disease Pathogen: Borrelia burgdorferi, bacterium Vector: Ixodes scapularis (black legged tick) primary vector in East and midwest. In areas were farmland has reverted to fields and forests and regrowth forests. Reservoir Host: White footed mice (Peromyscus leucopus), pine vole, eastern chipmunk, grey squirrel, oppossum in eastern US. Reproductive host: White tailed deer
Tick life cycle Requires 1 2 years, depending on the availability of hosts The overwintering stage varies between een tick species. American dog tick adults and larvae Lone star tick nymphs and adults Black legged tick larvae and adults
eggs nymph eggs lizards, birds and rodents spring winter summer fall deer and other large mammals larvae lizards, birds and rodents adults Ixodes scapularis has a 2 year life cycle in the southeastern US.
Common wildlife hosts of ticks in NC American dog tick (Dermacentor variabilis) larvae and nymphs adults vole white-footed mouse raccoon dog Lone Star tick (Amblyomma americanum) larvae, nymphs and adults (except birds) birds gray squirrel raccoon dog deer Black-legged tick (Ixodes scapularis) larvae and nymphs adults skink birds w-f mouse dog deer
Lone Star tick is the most important nuisance species in NC. Most abundant tick species in the SE US. All stages readily attack humans.
Management Strategies for Lone Star Ticks Personal protection Local application of acaricides Landscape management Host H exclusion Host targeted targeted acaricides
Remove ticks promptly! Dermacentor variabilis transmits Rocky Mountain Spotted Fever within 24 hours of attachment. Lyme Disease is transmitted about 24 hours after attachment of Ixodes scapularis.
NCSU Free Iphone/Ipad Tick ID app