MODULE 11: Mites (Suborders: Mesostigmata, Thrombidiformes and Sarcoptiformes)
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/249
There's no tags or description
Looks like no tags are added yet.
250 Terms
What is the defining location and number of stigmata in Mesostigmata?
A single pair of stigmata lateral and outside the third pair of coxae
How large are most Mesostigmata mites, and how large may they become when fully engorged?
Most are not less than 0.3 mm and may reach 1.0 cm when fully engorged
What may the body of Mesostigmata mites be covered with?
Spines or hairs
What is the shape of Mesostigmata mouthparts?
Long, slender, and needle-like
How do the legs of Mesostigmata mites compare with their body margins?
They are long and extend beyond the body margins
How is Mesostigmata transmitted, and where is its entire life cycle spent?
Direct contact and the entire life cycle is spent on the host
How many nymphal stages may occur in Mesostigmata before adulthood?
Two or three nymphal stages
What type of parasites are most Mesostigmata?
Obligate parasites
Which family primarily parasitizes birds but may also occur in mammals?
Dermanyssidae
Where do Dermanyssidae mites reside during the day, and when do they feed?
Nests and roosts during the day and feed on sleeping birds at night
What is the common name of Dermanyssus gallinae?
Red mite of poultry
Which species of Dermanyssus affects domestic and wild birds and may also affect humans in temperate zones?
Dermanyssus gallinae
Do the larvae of Dermanyssus gallinae feed?
No
What color is Dermanyssus gallinae when newly engorged?
Red
When do the nymphs and adults of Dermanyssus gallinae visit the host?
At night
Where do nymphs and adults of Dermanyssus gallinae hide between meals?
Cracks and crevices
What are the effects of Dermanyssus gallinae infestation?
Irritation, listlessness, and decreased production
Which pathogens can Dermanyssus gallinae transmit?
Borrelia anserina, St. Louis encephalitis, Eastern encephalitis, and Western encephalitis
What is the common name of Ornithonyssus sylviarum?
Northern fowl mite
Which mite affects fowl and other birds in temperate countries and causes pruritus, anemia, and weight loss?
Ornithonyssus sylviarum
Which diseases can Ornithonyssus sylviarum transmit?
Fowl pox, St. Louis encephalitis, and Eastern and Western encephalomyelitis
What is the common name of Ornithonyssus bursa?
Tropical fowl mite
Which mite commonly affects chickens and other birds in the Philippines and is known as hanip?
Ornithonyssus bursa
What color is Ornithonyssus bursa when newly engorged?
Red
How long can Ornithonyssus bursa survive off the host?
No more than 10 days
What are the pathogenic effects of Ornithonyssus bursa compared with O. sylviarum?
Similar pathogenic effects
Do the larvae of Ornithonyssus bursa feed?
No
Where are the eggs of Dermanyssus mites deposited, and how many are laid?
One to five eggs in the nest or fluff of feathers, especially around the vent
How long does it take Dermanyssus eggs to hatch into larvae?
Three days
How long after the protonymph stage does the deutonymph feed again?
One to two days
How long after the deutonymph stage does the adult emerge?
One to two days
What is the stated entire life cycle duration of Dermanyssus mites?
Six to eight months
What is the common name of Ornithonyssus bacoti?
Tropical rat mite
Which mite parasitizes rats and humans, is common in the Philippines, and transmits several pathogens?
Ornithonyssus bacoti
Which pathogens can Ornithonyssus bacoti transmit?
Yersinia pestis, Rickettsia typhi, and Coxiella burnetii
Which parasite uses Ornithonyssus bacoti as an intermediate host?
Litomosoides carinii
What is the common name of Allodermanyssus sanguineus?
House mouse mite
Which mite vectors rickettsial pox caused by Rickettsia acari?
Allodermanyssus sanguineus
What is the common name of Echinolaelaps echidninius?
Spiny rat mite
Which mite is the definitive host of Hepatozoon muris in rats?
Echinolaelaps echidninius
Where are Railletia auris and R. rhopkinski found?
External ear canal of cattle in America and Europe and ears of antelopes
Which mite inhabits the nasal passages and sinuses of dogs?
Pneumonyssus caninum
What clinical signs are caused by Pneumonyssus caninum?
Reddening of nasal mucosa, sneezing, head-shaking, and nose rubbing
Where is Pneumonyssus simicola found?
Bronchi of rhesus monkeys
Which suborder includes chigger mites or harvest mites?
Thrombidiformes
What is the family name of chigger mites or harvest mites?
Thrombiculidae
What may or may not be present on or near the gnathosoma of Thrombiculidae?
A pair of stigmata
Which structures are highly developed in Thrombiculidae?
Palpi
What gives Thrombiculidae their velvety appearance?
Dense, feathered hairs covering the body
What structure makes the body of adult chiggers appear divided into two parts?
A deep furrow between the propodosoma and metapodosoma
Which stages of chiggers are free-living?
Nymphs and adults
Do adult chiggers copulate?
No
How do chigger larvae obtain tissue fluid from their host?
They hydrolyze the cuticle by salivary secretion and form a stylostome through which tissue fluid is sucked
Which chigger species affects domestic animals, birds, and humans and causes irritation, inflammation, and pruritus?
Thrombicula autumnalis
Where do adults of Thrombicula autumnalis live?
Soil
What may result from secondary bacterial infection caused by Thrombicula autumnalis?
Dermatitis
Which chigger species vectors Rickettsia tsutsugamushi?
Thrombicula akamushi
What diseases are associated with Thrombicula akamushi in the reviewer?
Mite or scrub typhus and River Valley fever
What is the common name of Thrombicula sarcina?
Leg itch
Which chigger species affects sheep in Queensland and attaches to the pastern, coronet, and heel?
Thrombicula sarcina
Which Thrombicula species affects mammals, birds, reptiles, and humans in the United States?
Thrombicula alfreddugesi
Which Neochongastia species is listed as important in the reviewer without further details?
Neochongastia philippinensis
Which chigger species affects mammals, turkeys, and quails and reduces the value of dressed fowl through skin lesions?
Neochongastia americana
Where are chigger eggs deposited?
Moist soil
How long does it take chigger eggs to hatch into larvae called tungao?
Ten to twelve days
How long do chigger larvae feed on tissue fluids after attaching to the host?
Two to ten days
Where does the chigger larva go after feeding?
It drops to the ground
How long after the larva drops to the ground does the non-parasitic nymph appear?
About one week
Which chemicals are used to spray ranges to control chigger nymphs and adults?
One percent malathion, chlordane, or toxaphene
What is applied to skin lesions caused by chiggers?
Sulfur in petrolatum
Which family includes worm-like, cigar-shaped mites with stumpy legs?
Demodicidae
Where do Demodex mites live?
Hair follicles and sebaceous glands
What is the relationship of Demodex mites to the skin?
Skin commensals
What is the host specificity of Demodex mites?
Host-specific
What unusual larval form occurs in the life cycle of Demodex?
A second larval form called the protonymph, which is hexapod
Why may Demodex mites in older animals be less accessible to surface-acting acaricides?
They may move deeper
In which internal locations may Demodex mites be found?
Blood, spleen, and lymph nodes
Which Demodex species infests dogs?
Demodex canis
Which Demodex species infests sheep?
Demodex ovis
Which Demodex species infests goats?
Demodex caprae
Which Demodex species infests horses?
Demodex equi
Which Demodex species infests cattle?
Demodex bovis
Which Demodex species infests pigs?
Demodex phylloides
Which Demodex species infests humans?
Demodex folliculorum
Which Demodex species infests carabaos?
Demodex bubalis
Which Demodex species infests rabbits?
Demodex cunuculi
Which Demodex species infests rats?
Demodex musculi
Which Demodex species infests guinea pigs?
Demodex gambiae
Where is the entire life cycle of Demodex spent?
Hair follicles and sebaceous glands
Where does the male Demodex occur?
At or near the skin surface
How many eggs does a female Demodex lay in a hair follicle?
Two to 24 eggs
What is the egg stage in the Demodex life cycle called in the reviewer?
Morulate eggs
Which Demodex stage is the second larval stage and has three pairs of legs?
Protonymph
How many pairs of legs does the Demodex deutonymph have?
Four pairs
How long is the entire life cycle of Demodex?
Twenty to 35 days
How is demodectic mange transmitted?
Direct contact
What are the predisposing factors for demodectic mange?
Age, short hairs, animal condition or nutrition, intercurrent infection, frequent bathing, and undue use of alkaline soap
What role do immune factors play in demodectic mange?
They play a large part in its occurrence and severity
What genetically transmitted factor may a dam carry that predisposes offspring to Demodex?
A factor resulting in immunodeficiency to Demodex attack
How does Demodex affect cell-mediated immunity?
It blocks cell-mediated immunity and suppresses the normal T-lymphocyte response