Ticks & Mites Flashcards Preview

Parasitology > Ticks & Mites > Flashcards

Flashcards in Ticks & Mites Deck (47):

To which family do ticks and mites belong to?



What is particular about the Arachnida family?

larvae have 6 legs, nymphs and adults have 8 legs
all are wingless


How do ticks move?

they crawl (cannot fly or jump)


How do ticks get to their host?

they wait on grass blades and vegetation no more than 1 meter high
they can sense the potential host's presence and wait for them


How do ticks sense their hosts?

they have complex sense organs to detect carbon dioxide released by a host


Do all ticks cause disease in animals?

no, relatively few actually do


How are ticks different from other Arthropods?

lack antennae
first pair of appendages form modified pincer chelicerae


What are the different mouth parts on the tick?

palps, chelicerae, and hypostome (aka feeding tube with angled hooks)


What do most hard ticks secrete?

a substance from their salivary glands that further helps them to adhere to the host. It dissolves when they are done feeding


How do you remove a tick?

use tweezers to squeeze the head and pull directly upwards.
Do not squeeze the abdomen so as not to release the bacteria.
Do not leave the head behind, it can cause an infection.
Do not use a match or petroleum jelly, it will cause it to burrow deeper


What do ticks release that help them take their blood meal?

A substance from their salivary glands that prevents the blood from coagulating


What are the two groups of ticks and what are the main differences?

Ixoidae (hard ticks): have a hard shell behind the mouthparts. Shaped like a flat seed. Feed on dogs
Argasidae (soft ticks): Do not have a shield, shaped like a large raisin. Feed on birds or bats


Describe the life stages of the hard tick

larvae (6 legs) take a blood meal -> nymphal stage (8 legs) and feed -> adult and feed again -> female lays a thousand eggs and dies.
Eggs are lain in the environment


How long do hard ticks live for?

They can go for months without feeding, so anytime under a year to three years


How many hosts do hard ticks have?

can complete life cycle on one, two, or three hosts


How do hard ticks spend the winters?

free-living (not attached to a host)


When does the female hard tick usually fall off the last host and lay her eggs?

in the fall. The eggs hatch before the winter and the larvae hibernate for the winter


How many times do female hard ticks feed?

can detach from host and feed several times


Which host are humans?

first, second, or third


What is the difference between hard tick and soft tick molts?

-most soft ticks will usually undergo several nymphal feedings and molts before becoming adults
-still one feeding per stage though
-females lay eggs in several small batches
-because of this, soft ticks usually live longer than hard ticks


Which tick species transmit disease?

Amblyomma: lyme disease, rocky mountain spotted fever
Dermacentor: RMSF, colorado tick fever, lyme disease, tick paralysis
Ixodes: lyme disease, babesiosis
Rhipicephalus: RMSF, lyme disease
Ornithodoros: tick-borne relapsing fever
Carios: tick-borne relapsing fever


Which tick species is associated with lyme disease?

Ixodes capularis, aka black legged deer tick


Which bacteria cause lyme disease?

Borrelia burgdorferi (North America) and Borrelia afzelii (Europe)


How do you know if you have lyme disease?

usually will have bulls-eye shaped skin rashes


How is lyme disease treated?

with antibiotics


What complications can lyme disease cause?

disease of the joints, nerves, and heart


Which bacteria causes rocky mountain spotted fever?

Rickettsia rickettsii


Which ticks transmit RMSF?

dog tick Dermacentor variabilis and wood tick Dermacentor andersoni


What are the symptoms of rocky mountain spotted fever and how can it be treated?

fevers and nausea, then skin rashes on the arms or ankles, followed by joint pain, stomach pain and diarrhea.
antibiotics are used to treat


What are the two species of dust house mites?

European house dust mite: Dermatophagoides pteronyssinus
American house dust mite: Dermatophagoides farinae
(species not necessarily confined to those areas)


What do house dust mites feed on?

organic detritus such as dead skin flakes


Which allergic reactions do dust mites cause and how?

their potent digestive enzymes in the gut transmitted in their feces causes wheezing and the mite's exoskeleton
can cause hay fever, eczema and asthma


Which species of mites causes scabies?

Sarcoptes scabei


How does the scabies mite move on the body?

burrows in the moist areas of skin (web of fingers, armpits, etc) and spreads and deposits eggs as it goes along


Where do the scabies mites burrow through and what are their burrows called?

burrow into intact stratum corneum and construct almost invisible burrows called molting pouches


How can you distinguish different mite stages?

it is very difficult, the differences are subtle


When do scabies mites mate?

When the male penetrates the molting pouch of the female
this only happens once and the female is fertile for life


How do mites attach themselves to human skin?

using their sucker-like pulvilli


What percentage of eggs laid will grow into adults?



How are scabies mites transmitted?

through skin-skin contact
occasionally through bedding or clothing (very difficult to sterilize)


What can be used to treat scabies mite infections?

permethrin cream (a neurotoxin)


What is the species name of the Varroa mite?

Varroa jacobsoni


Which species do varroa mites infect?

honey bees.
-they feed on adult bee hemolymph and weaken them
-feed on larvae and pupae, causing deformation of their wings and bodies


Where do the female varroa mites lay their eggs?

on bee brood cells


How is the varroa mite spread?

-hitchhiking on bees to reach other bees;
-when stronger bees rob honey from one colony, they can become infected;
-hitchhiking on other insects that go to flowers;
-through beekeeping equipment


Which varroa mite sex is larger and which one emerges from the egg first?

the female is larger and the male hatches from the eggs first


Which country is thought to be free of varroa mites?