Arthropods Flashcards
What is the most prominent blood sucking dipteran?
Family Culicidae: made up of mosquitoes.
What is the life cycle of culicidae (mosquito)?
- Eggs
- Larvae - 1st molt in 5 - 6 days (3x total); they are filter feeders
- Pupae - stage that lasts 2 - 3 days; non-feeding
- Adults - lifespan 6 - 7 days; they mate once
What are the sufamilies within the culicidae family?
Anopheline: anopheles sp.
Culicine: aedes sp.
Culicine: culex sp.
What diseases are the anophelines vectors for?
Intermediate host/vector for plasmodium spp.
What diseases are the culicines vectors for?
Yellow fever, fengue fever, west nile encephalitis
How do you control for the culicidae family?
Control by implementing:
- larvivorous fish (guppies)
- ‘beneficial’ mosquito larvae - that feed on other mosquitoes
- sticky mustard seeds - prevent larvae from eating
- draining breeding sites
Facultative myiasis
Where do they deposit their eggs?
What can it cause?
- normally eggs are deposited in feces, rotten carrion, garbage
- occassionally they are deposited in contaminated wounds
It can cause dermatitis, numerous maggots, pungent odor, inflammation
Facultative myiasis:
What species are examples of this process?
Who are their hosts?
What type of feeders are they?
Blow flies/bottle flies
- hosts: Any mammal
- vomit-drop feeders
Obligatory myiasis
- define
- What is the main difference between facultative and obligatory myiasis
- Larve MUST use animal host to complete its life cycle by laying its larvae in living tissue, uncontaminated wounds, soft tissue.
- Obligatory myiasis must ingest LIVING tissue in order to complete their lifecycle.
Cochliomyia hominivorax
- what form of myiasis do they use?
- common name?
- are they reportable?
- who are their hosts?
- obligatory myiasis
- “primary screwworm”
- eradicated by sterile male release in US and central america
- they are reportable!!
- they affect any mammal; first fly on the scene with fresh, living tissue
Cochliomyia hominivorax
- pathogenesis
- diagnosis
- treatment
- pathogenesis: toxemia, bacterial infection, death
- diagnosis: larval ID, dermatitis, pungent odor
- treatment: remove larvae, treat secondary bacterial/fungal infections
Cuterebra spp.
- what type of myiasis do they use?
- what is their common name?
- hosts?
- what is important about adults?
- they use obligatory myiasis
- “wolves” , “warbles”
- hosts: cats, dogs, rabbits, rodents
- adults are non-parasitic
Cuterebra spp.
Lifecycle
- Eggs deposited near entrance to burrow/nest
- They enter host
- Migrate thru host
- Subcutaneous cysts produced (sometimes nasal or oval)
Cuterebra spp.
- pathogenesis
- diagnosis
- treatment
Pathogenesis
- cysts, swellings - secondary infections
- heals slowly
- larval migrations
Diagnosis
- larval ID
Treatment
- surgically remove larvae; dont break them it will cause anaphylaxis
- no approved treatment
- ivermectin, milbemycin, selamectin may kill larvae
Class insecta: orders anoplura & mallophaga
What parasite is part of this order?
What disease process do they cause?
What is it’s veterinary importance?
- lice!
- causes pediculiasis: infestation of lice
- veterinary importance: irritation to host, severe infestation can cause anemia, disease vectors, social stigma
Anoplura and mallphaga: lice
Lifecycle
- Females produce 1 egg (nit) at a time that is cemented to hair shaft or feather
- Egg (nit) hatches 1 - 3 weeks - 3 nymphal stages
- Adults within 4.5 weeks
- They are a permanent ectoparasite and are stenoxenous (very host specific)
What is the difference (and names) of the two lice groups?
Mallophagia
- chewing lice feeds on skin cells
- their head is wider than their thorax
Anoplura
- blood feeders
- head is narrower than thorax
Anoplura
- who is their host?
- name some examples
- mammals only
Linognathus setosus (dog)
Pediculus humanus humanus (body)
Pediculus humanus capitis (head)
Pthirus pubis (pubic)
Treatment of anoplura & mallophagia
Selamectin
Fipronil
Imidacloprid
Carbaryl shampoos, sprays, dips
Class insecta: order siphonaptera
- what parasite is part of this group?
- what do they cause?
Fleas!
They cause siphonapteriasis: infestation with fleas
- Name a common flea found on dogs and cats
- What flea carries bubonic plague?
- What flea is found in poultry, dogs, cats, and humans and is also known as the stick-tight flea?
- Ctenocephalides felis
- Xenopsylla cheopis
- Echidnophaga gallinacean
Where are most stages of the host found?
Off the host
- Where are flea eggs laid?
- When do they hatch?
- How many eggs does a female flea lay?
- Laid on host, quickly fall off
- They hatch in 2 - 16 days
- Females > 500 eggs
Flea larvae
- How long is the larval stage?
- How many molts?
- What are they covered with?
- What do they feed on?
- What are they susceptible to?
- 7 - 10 days
- 2 molts
- Covered in setae
- Feed on “frass”
- Susceptible to heat and desiccation
Flea pupae
- how long is this stage?
- what makes this stage tricky to control?
- this stage can be completed in 4 days
- what makes this stage tricky is that emergence of adults can be prolonged up to 174 days depending on environmental conditions
Flea adults
- how often do they mate?
- when do they feed after getting on host?
- they mate once
- they begin feeding
Flea allergy dermatitis
- definition
- what is severity related to?
- at what age does this disease onset in hosts?
Defined: biting fleas that introduce salivary proteins (antigens).
Severity is related to duration of feeding and amount of salivary protein introduced
3 - 5 years of age
Flea allergy dermatitis
- geography of lesions: where are they most commonly found
- what are the characteristics of these lesions?
- lumbo-sacral region, caudal thighs, proximal tail, ventral abomen
- characteristics of lesions: papules, crusts, alopecia, excoriations, erythema, hyperpigmentation.
Flea control
Combination of what?
Combo of chemical and mechanical means which target both the animal and its envionrment
What do host-targeted flea controls consist of? (2 types)
- Insect growth regulators (IGRs)
2. Insect development inhibitors (IDIs)
What issues are important in flea control?
- Client compliance
- Pupal window (adult quiescence)
- Performance of adulticides
- Microenvironments and flea infestations
- Client perceptions
- Insecticide resistance
Class arachnida: order acarina
What is this order made up of?
What are the 2 families this order is made up of?
What is unique about the females?
- order made up of ticks!
- 2 families: ixodidae = hard ticks, argasidae = soft ticks
- only the females engorge themselves with blood
Tick paralysis
What is it?
How is it reversed?
ascending flaccid paralysis
- neurotoxin in tick saliva
- disrupts nerve synapses in spinal cord
- blocks neuromuscualar junctions
- once you remove the tick the process will reverse
Order: acarina (ticks)
Basic body division
- capitulum
- idiosoma: scutum (equivalent of chest armor) and festoons (equivalnt of scoots on a turtle shell)
Order acarina: ticks
Lifecycle
- Eggs
- Larva - seed tick
- Nymph - sexually immature
- Adult
Entire lifecycle 6 weeks to 3 years
What is questing?
When a tick sticks its legs out when they sense heat or carbon dioxide form their prospective host
How many a tick’s lifecycle vary?
It varies depending on how many hosts it has: one, two or 3.
One-host: hatch in the environment, attach and molt 2x on the host, then drop off and oviposit
Two-host: hatch in environment, attach to host 1 for one molt, and get off. On the 2nd host, they will complete their development and feeding.
3-host: same as above with one extra host. Can take a long time to develop into an adult.
Order acarina: disease transmission
What are the 2 types
Transstadial transmission: disease/pathogen acquired during one life stage stays with teh tick and can be passed in another
Transovarial transmission: disease/pathogen passed from female to developing offspring
What are the two families within order acarina and their identifying characteristic?
Family argasidae: soft tick
- they take blood meal and hop off host
- females dont engorge
Family ixodidae: hard tick
- easy to see mouthparts
- hang out on host
- females engorge
Rhipicephalus sanguineus
- family?
- common name
- how many hosts does it have in its lifecycle
- where is it found
- what disease does it cause
- what pathogens does it carry
- family: ixodidae
- “brown dog tick”
- 3-host lifecycle
- found throughout the US
- causes tick paralysis
- carries: rickettsia rickettsii (RMSF), ehlichia canis, babesia canis, hepatazoon canis
Ixodes scapularis
- what family is it part of?
- common name
- how many hosts?
- geography?
- what disease does it cause?
- what diseases does it carry?
- family ixodidae
- “black legged tick” “deer tick”
- 3 hosts
- found in the southeast, south central US
- tick paralysis
- borrelia burgdorferi (lyme disease!!!!) main transmitter, babesia microti, anaplasma marginale
Amblyomma americanum
- what family is it part of?
- common name
- how many hosts
- what does it cause?
- geography
- disease vectors
- family ixodidae
- “lone star tick”
- 3 hosts
- causes tick paralysis
- southern US
- causes rickettsia rickettsii, francisella tularensis (tularaemia)
Dermacentor variabilis
- family name?
- common name
- how many hosts
- geography
- diseases?
- vectors for ?
- family ixodidae
- “american dog tick” “wood tick” (super common in Fl!!)
- 3 hosts (dog prefered)
- most of US
- tick paralysis
- disease vectors for: rickettsia rickettsii (RMSF), anaplasma marinale
Tick control in dogs
- manual removal
- insecticides/acaracides
Tick control in cats
Manual removal
Insecticides: fipronil (works best in cats), 1% pyrethrum
Order acarina: mites
- how are they ID’d
- what is the difference between larva and adults?
- how many body divisions do they have?
- microscopic or barely visible
- ID’d thru their pedicels (legs/stalks)
- larva have 6 legs, adults have 8 legs
- 2 body divisions
Otodectes cynotis
- common name
- hosts:
- where are they found on their host?
- temporary or permanent
- “ear mite”
- host: dogs, cats, foxes, raccoons, ferrets
- found in external ear canal
- permanent
Otodectes cynotis
Clinical signs and diagnosis
Clinical signs
- thick, tarry exudate
- host shakes head, scratches ears
- infections of middle/inner ear can develop
Diagnosis
- swab: dont necessarily need oil to look on slide
Otodectes cynotis
Treatment
Cats/dogs: selamectin
Cats: ivermectin, milbemycin - products formulated for application to ear canal
- mineral oil and massage
- abx secondary infections
- rarely zoonotic
Demodex canis
- common name
- host:
- where is found on teh host
- temporary or permanent
- “follicle mite of dogs”
- dogs
- found in hair follicles and adjacent sebaceous glands
- permanent parasite
- found in skin of most normal dogs
Difference between localized and generalized demodectic acariasis
Localized
- skin redness
- partial hair loss
- usually no itching
- commonly on face, around eyes
Generalized
- more severe
- large patches of alopecia
- secondary bacterial infections
- pyoderma
Demodex canis
- how its transmitted
- diagnosis
- treatments
- direct contact: usually mother to offspring, which is why its around face on puppies
- diagnosis: DEEP skin scraping, pusutle and abscess contents
- treatments:
localized = usually resolves spontaneously and wont need treatment
Generalized = amitrax dip. Non approved treatments are ivermectin, oral milbemycin and topical moxidectin
Cheyletiella spp.
- common name
- hosts
- where its found on host
“Walking dandruff”
- dogs and cats, temporary residence on humans
- found in fur coat, keratin layer of dermis
Cheyletiella spp.
- clinical signs
- diagnosis
- treatmetn
Clinical signs
- asymptomatic
- if severe: dandruff, itchiness, reddened skin, hair loss
Diagnosis
- skin scrapings not necessary
- tape, fecal and look under microscope
Treatment
- easily killed; most flea shampoos work
- ivermectin, fipronil, selamectin
Pneumonyssoides caninum
- common name
- hosts
- how its transmitted
- what does it feed on
- “nasal mite”
- hosts: dogs, other canids
- transmittd via direct contact also travel via fleas, lice, flies
- feeds on keratin layer of epidermis in nasal passages and sinuses
Pneumonyssoides caninum
Clinical signs
Diagnosis
Treatmetn
Clinical signs:
- reddening of mucosa, sneezing, head shaking, rubbing nose
Diagnose
- microscopic ID
Treatment
- ivermectin
- imidacloprid, and moxidectin
Notoederes cati "Common name" Hosts Where its found on host What do the females do?
“Notoedric acariasis mite”
- hosts: cats, rabbits - ZOONOTIC
- found mostly in ears and along the back of the neck.
- *Females particularly burrow/tunnel in epidermis**
Notoedres cati
Clinical signs
Diagnosis
Treatment
Clinical signs
- persistent prurius, alopecia, self mutilation
- hyperkeratosis, epidermal flakes
- yellow crusts
Diagnosis
- deep skin scrapings
- fecal exam
Treatment
- selamectin, fipronil
- ivermectin
Sarcoptes scabei
- “common name”
- hosts
- how is it transmitted
- where is it found on its main host?
- what is unique about females?
“Sarcoptic acariasis mite” , “itch mite”
Hosts: dogs, cattle, horses, sheep, goats, swine, ZOONOTIC, rarely cats
- transmitted via direct contact, highly transmissible
- On dogs its found in the muzzle, eyes, ears, feet.
Females burrow/tunnel in epidermis
Sarcoptes scabei
- clinical signs
- diagnosis
- treatment
Clinical signs
- irritation, itching, exudate form crusts
- thickening of skin, alopecia
- severe cases result in death
Diagnosis
- deep skin scrapings
Treatment
- treat all in contact animals
- selacmectin
- imidaclopromid/moxidectin
- SQ ivermectin
May temporarily infest humans
What family are the mosquitoes part of?
Culicidae
