Arthropods Flashcards
Outside host
Infection not infestation
Phylum Arthropoda- vet importance
Casual agents of disease
May produce venom or toxic substances
May serve as IH for protozoan or helminth parasites
May serve as vectors for bacteria, viruses, rickettsial or other pathogens
Characteristics of insecta
Segmented body with 3 pairs of segmented legs
A dorsal heart, ventral nerve cord
Complete digestive system and excretory system
Reproductive system- dioecious, separate sexes
Segmented insecta body
Head, thorax, abdomen
Simple lifecycle metamorphosis
Egg- larval and nymphal stage (smaller adults) to adults
Complex metamorphosis life cycle
Egg- larva and then puppate(hard covering) to adult
Anoplura
Suckling lice,
Mallophaga
Chewing lice
Diptera
2 winged flies
Siphonaptera
Fleas
Morphology of acarines
Head and body (idiosoma)
All simple lifecycle
Diptera
True flies
1 pair of wings, ectoparasites in adult form
Either permanent or temporary
Disease vectors- virus, bacteria, Protozoa
IH- protozoan and filarial parasites
Myiasis
Myiasis
Fly larvae grow inside and feed on tissue
Facultative myiasis
Normally egg in feces, garbage and rotten carrion
Occasionally deposited in contaminated wound, useful if correct species
Larvae ID- spiracular plate on posterior end, different in each species
Early lesions- dermitis, numerous/maggots, pungent odor, inflammation
Obligatory myiasis
Larvae must use animal host to compete life cycle- living tissue, organs, uncontaminated wounds, soft tissue
Larval ID- spiracular plates- finger print
Adult not parasite, larval stage- hypoderma, dermatobia, cochliomyia
