ENTO 208 1st Edition Lecture 19 Outline of Lecture 18TicksI. Phylogeny II. ImportanceIII. Anatomy IV. GeneraV. Tick life stagesOutline of Lecture 19Tick borne diseasesI. Tick behaviorII. Tick EcologyIII. Tick PhenologyIV. Direct impacta. Tick paralysisb. Allergiesc. Lyme diseaseV. Life Cyclea. Rocky Mountain spotted feverb. BabesiosisCurrent LectureTick borne diseases Tick behaviorHost seeking - passive (ambush), active (hunters)Questing behavior: front legs have sensory organs similar to antennae that sense things suchas vibrations to tell the tick that a host is coming (ixodes scapularis)Hunting: sense hormones, odors, etc. and travel to source (lone star)Feeding behavior - crawl up to a location on the host where it would be hard to push them off, hypostome is inserted and cement is secretedTick EcologyVarying degrees of host specificityStrict host associationBroad (catholic) host associationHost utilization depends on availabilityNidicolous ticks: live in nests or other shelters used by the hostsNon-nidicolus: Dispersed throughout landscape attacking passing hostsGround-dwelling birds are highly susceptible"Tick bomb" - large groups of larvae clumped in one placeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Tick PhenologyLarvae: June to SeptemberNymph: May to SeptemberAdult: February to May, September to late-December Direct impactDermatitis/AlopeciaExsanguinationTick toxicosisToxic reactions to tick bites (mostly soft tick)Weakness, fever, deathCattle, sheepTick paralysisHost reaction to secreted proteinsHumans - muscle weakness, loss of motor coordination, death w/in 48 hrs.Animals - dogs, rabbits, birdsAllergiesHost reaction (other than paralysis)Inflammation, rash, nausea, death (rashes may also be associated with disease agentsOften with soft ticks Lyme diseaseAgent: Borrelia burgdorferi (spirochete)#1 reported vector borne disease in USVectored by: Black legged tick (ixodes scapularis), carried by white footed mouseIn humans: early stage (bulls-eye rash, flu-like symptoms)Late stage (several months later, cardiac, neurologic, arthritic abnormalities) Life CycleEggs hatch into spirochete free larvae, feed on infected host, molts into nymph, feeds again, molts into adult, feeds on final host, drops off and lays eggs Rocky Mountain spotted feverAgent: rickettsia rickettsiiVectored by: Dermacentor variablis BabesiosisAgent: babesia spp protozoaVectored by (in US): Ixodes scapularisHuman babesiosis: Babesia microt, emerging disease, malaria-like symptomsCattle babesiosis: B. bovis or B. bigemina, affect the central nervous systemCattle tick fever (in TX): Theobald smith discovered the arthropod was linked to transmission of disease agent (1889)Cattle tick*most important tick of livestock in the world, has been confined to Mexico*short mouth
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