Arthropods

Ametabolous development

all life cycle stages look the same except size

Hematbolous development

life cycle stages look different

holometabolous development

the stages are like actually different like butterflies (most insects ~90%)

P. humanus humanus (sucking Lice)

body louse

P. humanus capitis

head house (sucking lice)

1. 3 nymph stages

2. cements nits (eggs) to fibers

3. <10 adults/host

4. common in crowded areas and institutionalized

P. humanus humanus life cycle

1. nits cemented to hairs

2. common in back of neck, behind ears

NOT eyebrows or eyelashes

P. humanus capitis life cycle

Left: head

Right: body

Identify

non-serious

no disease transmission

itching and scratching > red papules

VAGABONDS disease = skin thickening form years of lice infection

Louse pathology

Phthirus pubis

crab louse

1. Lice Typhus DEADLY = Rickettsia prowazeki

2. Trench Fever = Bartonella quintana

3. Relapsing Fever = Borrelia recurrentis

Name 3 diseases transmitted by louse vectors

Cimex lectularius

Bed bugs (of temperate regions)

1. bite sores

2. iron/hgb deficiency

3. hard to get rid of

Cimex lectularius pathology

Tunga penetrans - requires surgical removal and can contain wolbachia

chiggers

bubonic plaggue

what disease are fleas known to vector

Dermacentor andersoni

Rocky mountain wood tick

Dermacentor variabilis

American dog tick

Rocky mountain spotted fever

what disease is caused by Dermacantor andersoni. Is very seriois requiring hospitaliziation. Most common along northeasr coast

Dermacentor albipictus

Winter tick - feeds only in winter; moose tick with 20,000ticks/host

Amblyomma americanum; US and mexico (tropical) - can cause red meat allergy

Lone star tick; name epidemiology

Rhipicephalus sanguineus

brown dog tick

Rhipicephalus appendiculatus

Vector for East Coast Fever

Babesia bigemina

Texas cattle fever

Sarcoptes scabiei

sarcoptic mange

1. egg

2. larva (6 legs)

3. nymph (8 legs)

4. adult

life cycle stages of tick

lxodes scapularis

primary vector for Lyme disease

deer tick, can be fatal

vectors human granulocytic erlichiosis HGE

Borrelia burgdorferi

Lyme disease

Otobius megnini

spinose ear tick - the disgusting orange one that infects cattle

Argas persicus

fowl tick (birds and bats); can kill birds; painful and toxic human bite

Demodex follicularum; Demodex brevis

mites hair folicles; sebaceous glands

Demodex canis

dog follicle mite with red mange; can be fatal ; hard to control or cure

Orienta tsutsugamushi

vector for scrub typhus

Orienta tsutsugamushi pathology

Otodectes cyanotis

ear mites of dogs, cats, ferrets, rabbits

Dermatophagoides

dust mites