Ticks 1 Flashcards
Importance of ticks
Damage/bite wounds
Transmit disease**
Threaten human-animal bond
Blood loss
Tick paralysis
Methods tick use to find hosts
Use Haller’s organ - first pair of legs to detect CO2 & BO
Sense heat, moisture and vibrations
Questing - place to wait for host, common in grass ends
Tick paralysis
Progressive flaccid ascending paralysis - leads to respt paralysis and death
Caused by toxin produced by female ticks attached close to CNS - attached for several days prior to releasing
removal can prevent or increase recovery
Features of tick in the east US
All are hard ticks - ixodidae
Mouth project forward, scutum differentiates M/F
Life cycle includes 4 stages - egg, larva, nymph, adult
All are 3 host ticks
3 host tick life cycle
Each stage of the tick life cycle involve a separate host, time in between host involve a molting to a new phase
Larva have 3 pairs of legs and then molt to 4
5 species of ticks in the US
Dermacentor variabilis
Ixodes scapularis
Amblymma americanum
Rhipicephalus sanguineus
Haemaphysalis longicornis
Dermacentor variabilis
American dog tick
3-host life cycle
Larvae - rodents
Nymph - mid/small animals
Adults - mid/large animals
Recognizing dermacentor variabilis
Ornate tick - short mouthparts Square basis capituli
pattern covers scutum (m=full, f=partial)
Distribution of dermacentor variabilis
Life cycle vary in latitude, 3m south, 2y+ north
Adults prefer grassy meadows near roads
Common march - mid summer
Importance of dermacentor variabilis
Tick paralysis*
Primary vector of Rickettsia rickettsii *** RMSF
- between molting stages (transstadial) and mom to egg (transovarial)
Can also cause anaplasmosis in cattle
Dermacentor Andersoni
Rocky Mountain wood tick
Tick paralysis*
Transmits RMSF & tularemia
Found in western us
Ixodes scapularis
Deer tick/black legged tick
Young stages prefer small animals, birds - north, lizards - south
Adults prefer deer/large mammals
2y life cycles - can survive over winter
Recognizing Ixodes scapularis
NON ornate, LONG mp
All brown/black, deep bites
Anterior anal grove - all stages
Smallest ticks are the important ones (larvae only 0.5mM)
Distribution of Ixodes
Easter half of us and tiny parts of west coast / Utah
Life cycle of Ixodes scapularis
Larvae - late august/early fall
Nymphs - late winter (late summer by region)
Adults - late fall/early winter
Quest in woodland/margin woodland
Disease transmission of Ixodes scapularis
Lyme disease - borrelia burgdorferi
Anaplasmosis - Anaplasma phagocytophilum
Why is Ixodes scapularis expanding
Reforestation of large areas - create suitable habitats for the tick/host life stage
Climate change contributed to increase - not the main reason
Amblyomma americanum
Lone star tick
Long mouth parts
Females have a long star spot on margin of scutum, males are bland
Life cycle of Amblyomma americanum
Parasitize deer as larva, nymph, adult
Very promiscuous feeders - use ground nesting birds and med/large animals
ALL stages feed on: dogs, cats, horses, cattle, goats, ppl
Found on forest floor - respond highly to CO2
Distribution of Amblyomma Americanum
Widely distributed across eastern half of US
Texas up to Iowa and across to Maine
Importance of Amblyomma americanum
Cytauxzoon felis**
Tularemia - francisella Tularenis
Ehrlichia Ewingii and chaffeensis- cause canine granulocytic ehrlichiosis
Red meat allergies
Alpha Gal syndrome is ID to produce a type of food allergy to red meat.
Amblyomma maculatum
Gulf coast tick
3 host tick - each life stage feeds on different host species
L&N - SA, birds, rodents, rabbits
Adult - LA, dogs, coyotes, ruminants - ears**
Importance of Amblyomma maculatum
Hepatozoon americanum**
