Lecture 21 4/29/24 Flashcards
What are the unifying characteristics of Diptera?
-one pair of functional wings
-one pair of halteres used for balance
-complete metamorphosis
-most lay eggs
What is viviparous reproduction?
deposition of larvae
Which flies are capable of serving as disease vectors?
-horse/deer flies
-mosquitoes
-sand flies
-tsetse flies
-face/horn flies
-biting midges
What is myiasis?
invasion of living tissue by fly larvae, producing a pathological condition
What is facultative myiasis?
fly larvae usually eat dead meat, but may become parasitic
What is obligatory myiasis?
fly larvae cannot develop outside of host; require living flesh
How do male and female mosquitoes differ?
-males feed on nectar and are pollinators
-females feed on blood
Why must all stages of mosquito development stay on the water surface or on land?
they are dependent on oxygen
What is the life cycle of mosquitoes?
-mosquitoes lay eggs on land/near water
-eggs hatch into larvae, which are aquatic
-larvae develop into pupae, which are aquatic
-pupae hatch into adults, which live on land
Which three mosquito genera are of importance?
-Anopheles
-Aedes
-Culex
What are the characteristics of Anopheles spp. mosquitoes?
-single eggs with floats
-angled hind end
What are the characteristics of Aedes spp. mosquitoes?
-single eggs on “dry” surface
-horizontal hind end
What are the characteristics of Culex spp. mosquitoes?
-floating egg raft
-horizontal hind end
Which diseases can be spread by Aedes spp. mosquitoes?
-yellow fever
-dengue
-chikungunya
-zika
-heartworm
-eastern equine encephalitis
Where do Aedes spp. tend to breed?
small areas of water, such as in tree holes or tires
Which diseases can be spread by Culex spp. mosquitoes?
-west nile
-St. Louis encephalitis virus
-avian malaria
-heartworm
-western equine encephalitis
Which diseases can be spread by Anopheles spp. mosquitoes?
-malaria
-heartworm
-eastern equine encephalitis
What are the characteristics of Nematocera Simuliidae/black flies?
-small, stout bodied flies with short mouthparts
-black/gray/yellow brown
-breed in running water
-females require blood meal for egg maturation
What does it mean for Simuliidae to have exerate pupa?
the appendages are free and sometimes mobile
Which parasites are vectored by Simuliidae?
-Onchocerca spp.
-Dirofilaria ursi
-Leucocytozoon
-Trypanosoma
What are the characteristics of Nematocera Ceratopogonidae/biting midges?
-tiny flies that can pass through window screens
-long, slender antennae
-short mouthparts
-breed in water, decaying vegetation, or soils
-can cause a pruritic hypersensitivity reaction
Which diseases are vectored by biting midges?
-bluetongue
-African horse sickness
-epizootic hemorrhagic disease
-Onchocerca spp.
What are the characteristics of Brachycera Tabanidae/horse flies?
-“Aquatic,” found in muddy/marshy areas
-females require blood meal for egg maturation
-larvae may overwinter and pupate in spring
What are the characteristics of Tabanidae/horse fly pathogenesis?
-attacks and painful bites cause exhaustion
-mechanical vector for Anaplasma, anthrax, tularemia, EIA virus, and Besnoitia protozoa
-biological vector of nematodes such as Loa loa and Elaeophora schneideri
What are the characteristics of Cyclorrhapha?
-breed in decaying plant and animal material, manure or carrion
-DO NOT breed in water
-puparium opens with circular lid
-posterior spiracles trunks
-antennae have 3 segments with an arista
-parasitic adults or larvae
What are the characteristics of Cyclorrhapha Gasterophilidae?
-adult resembles a honey bee
-deposits eggs on horse
-larvae hatch and migrate through horse’s mouth to stomach
-L3 remain in stomach for up to a year before passing in feces to pupate
-may be pathogenic due to lesions caused by mouth hooks
What are the two species of Gaterophilidae?
-G. nasalis: in intestines
-G. intestinalis: in stomach
What are the two species of Cyclorrhapha Hypodermatidae?
-Hypoderma bovis: along spinal cord
-Hypoderma lineatum: along esophagus
What are the characteristics of Hypodermatidae?
-live on cattle
-cause cattle to become excited
-L3 seen as lumps on back of cattle in spring
-ruin hides used for leather
-eggs glued to hairs on legs
-larvae burrow through skin and migrate through connective tissue
What are the characteristics of Hypodermatidae treatment?
-treatment when larvae are grouped around spinal cord/esophagus can cause adverse reactions
-treat no later than 8-12 weeks before anticipated appearance of warbles
-in TN, do not treat after Halloween
What are the characteristics of Cuterebra spp.?
-L3 is large, dark brown to black, with spines
-L1 hatches from egg, crawls onto host’s fur, and enters body through orifices
-larvae end up in SQ connective tissue
-may go to the brain, nasal, or oral regions
-cats and dogs are accidental hosts
What are the characteristics of Musca autumnalis/face flies?
-adults crawl about faces of horses and cattle
-4 dark stripes on thorax
-eggs deposited in fresh feces
-larvae pupate in dried feces or nearby soil
-pupa are white
Which species/diseases are vectored by Musca autumnalis/face flies?
biologic vector: Thelazia spp.
mechanical vector: infectious bovine keratoconjunctivitis
What are the characteristics of Haematobia irritans/horn flies?
-found on backs of cattle and horses
-remain on host during warmer seasons
-bite and suck blood
-lay eggs in fresh manure
-larvae feed on manure
-overwinter as pupae in temperate areas
-cause irritation, weight loss, and milk production loss
-biological vector of Stephanofilaria
What are the characteristics of Stomoxys calcitrans/stable flies?
-slightly larger than house flies
-4 longitudinal stripes on thorax
-broad abdomen with checkerboard of spots
-breed in piles of decomposing vegetation or manure
-vicious biters
-both sexes feed on blood
What are the characteristics of C. hominivorax/screw worm?
-female flies are attracted to wounds
-can lead to secondary infections
-sterilized males used for control in US
-eradicated in US; cases should be reported
-treatment via OPs, carbamate, pyrethroid
What are the characteristics of Hippoboscidae?
-dorsoventrally flattened
-may/may not have wings
-antennae in pits in sides of head
-piercing mouthparts
-females retain larvae until they are ready to pupate
What are the characteristics of Melophagus ovinus/sheep ked?
-female deposits L3 onto hairs, where it pupates
-pierce skin to feed on blood
-sheep scratch and bite themselves
-excrement permanently discolors wool
-can cause anemia
-entire life cycle occurs on sheep
-hosts a nonpathogenic Trypanosoma parasite
