Ticks & Mites Flashcards
To which family do ticks and mites belong to?
Arachnida
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?
10%
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?
Australia
