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21 Cards in this Set
- Front
- Back
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What is the phylum, class and two families of tick well be dealing with?
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Phylum Arthropoda
Class Arachnida Family Argasidae - soft ticks Family Ixoidae - hard ticks |
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Describe the hard tick life cycle and sexually dimorphic characteristics.
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Egg, larvae has 3 pairs of legs, nymph and adult both have 4 pairs of legs. Females are larger with different patterns.
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What are some reasons ticks are good vectors?
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- Most ticks are persistent blood feeders that feed slowly
- Ticks have few natural enemies and feed off MANY hosts - highly scerlotized, long lived - high reproductive potential |
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Describe the transovarian, transstadial, and interstadial transmission of pathogens by ticks.
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- transovarian occurs when the adult female tick transmits the disease to her larvae and occurs with one host ticks or those that complete both molts without leaving the host
- transstadial spreads with multiple stages - interstadial disease transmission occurs in two and three host tick species - meaning the nymphs fall off after engorgement to molt and can pick up another host as an adult (two host) and those whose larvae AND nymphs drop off to molt, therefore can attach to a different host in each stage (three host) |
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What are some additional ways ticks can cause disease other than as vectors?
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- dermatoses due to reactions from their mouth parts possibly due to biologically active or toxic substances released from the ticks
- they can also cause exanguination - tick paralysis can be caused by 1 or multiple ticks - ticks cause otoacariases |
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What are some major identifiers of hard ticks?
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- mouthpart region is the capitulum
- idiosoma region is the back body part that's rounded - there is a also a "shield" pattern also known as a scutum which is all the way down the idiosoma (dorsal surface) in males, but in females it only goes 1/2 way back - ticks can have ant., post., or no anal groove |
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What are the parts of the capitulum?
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- palps is the outer larger part
- chelicerae are the sharper parts just medial to the palps - have a sharp blade like look - hypostome is the middle part that secretes a sticky fluid for adhesion to the host with small teeth also known as denticles |
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What are some additional structures of hard ticks including sexually dimorphic characteristics?
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- capitulum is easily visible
- festoons are the bumpy parts on the back region that are often present as sexually dimorphic characteristics - adults may have an ornate scutum and have varying colors which is also sexually dimorphic - scutum can also be variable as sexually dimorphic |
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What are some of the structures of soft ticks?
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- oval, leathery body with hidden capitulum
- no scutum, no festoons, no sexual dimorphic features |
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What are the types of tick mating and species examples of these?
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- prostriate mating occurs in the environment, males mate with females on the host, the host will have more females than males, an example is Ixodes.
- metastriate mating occurs following a blood meal on the host, this is necessary so sexual maturity can occur, will find more males on the host in these spp. because the female fall off, seen in ripicephalus spp, dermacentor spp, and amblyomma spp. |
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Distinguish between the two different types of host finding by ticks.
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- nidicolous ticks live in the host den or nest,this is the typical method by soft ticks
- non nidicolous spp are found along paths or trails where the host is likely to pass, these ticks "quest" or look for a host by sensing CO2 levels. |
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Describe aspects of tick feeding.
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- pool feeders that excrete substances that affect hemostasis and immune response
- blood meal concentrate is released into the host with toxins and pathogens - pathogens are protected in the gut of ticks for long periods of time - ticks require several days to to complete feeding and must be feed for a certain amount of time to transmit specific diseases - |
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What are some characteristics of pathogen transmission? What are some examples of pathogen transmission time in ticks carrying lyme disease?
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- pathogens must undergo development and activation within the tick before they can be released
- pathogens then must migrate to the mouthparts to be transmitted - in some cases immunity of the host may increase - Ixodes pacificus and scapularis takes 48 hours to transmit the Lyme dz pathogen - I. ricinus takes 17 hours to transmit the Lyme dz pathogen |
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What are some spp. of soft ticks we need to be concerned with? Describe the climate these ticks are most commonly found?
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- Argas persicus which is a fowl tick
- Otobius megnini is a spinose ear tick sometimes found on dogs and cows - hot, dry, rocky areas, including barns |
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Describe some characteristics of the Ixodes spp. and what type of tick these spp are.
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- hard ticks also known as black legged (pacificus) or deer tick (scapularis)
- scapularis spp found in the eastern US and pacificus spp found in the western US - these ticks have an arch anterior to the anus and a genital opening can be found in the adults - these spp. have no eyes, festoons, or ornamentation - these are 3 host ticks with a long life cycle, up to 2 years - these spp transmit lyme disease pathogen Borrelia burgdorfei, also transmit Babesia to humans - Anaplasma phagocytophilium is also transmitted by these ticks - larvae and nymph typically feed on small mammals and birds, then adults feed on deer and larger animals |
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Describe some characteristics of Amblyoma americanum.
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- hard ticks also known as lone star ticks, adult female bears a large white spot on her scutum, both sexes have festoons on their scutum
- 3 host ticks, larvae and nymphs like birds and small animals, adult feed on large animals - these ticks transmit Rocky Mountain spotted fever, ehrlichiosis, and STARI (southern tick associated rash illness) which is a lyme disease like illness |
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Describe characteristics of the Amblyomma maculatum.
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- hard tick spp. that are found on cows and dogs
- transmit Hepatozoon americanum which is a severe disease usually resulting in death - scutums are ornate on both sexes with festoons |
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Describe the Dermacentor variabilis spp of hard ticks.
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- american dog tick, 3 host tick spp
- larvae and nymphs feed on mice and small mammals, adults feed on large animals - life cycle is 1-2 years - both sexes are ornate with festoons - most common tick that transmits Rocky Mountain spotted fever - also transmit Cytauxzoan felis to cats and Ehrlichiosis canis to dogs |
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Describe characteristics of Rhipicephalus sanguineus.
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- brown dog tick that is a 3 host spp tick BUT prefers the dog for ALL stages
- reproduces in the home and kennel environments, can complete life cycle in 2 months - festoons on both sexes but neither has ornate scutum - transmits Ehrlichiosis canis, Anaplasmosis, Babesia, and Hepatozoon |
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Describe the Rhipecephalus annulatus spp of hard tick.
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- Texas cattle fever tick that is a one host tick
- eradicated from the US currently, still present in Mexico - reportable tick spp. |
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Describe the causes and problems that occur with tick paralysis.
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- toxic substances in saliva that if especially released in location on neck or head cause ascending motor paralysis
- it is possible that one tick can cause this but often several are required. - must remove the tick to treat the problem - most commonly caused by Dermacentor spp. and Amblyomma spp, but all spp. can potentially cause it |
