Lecture 21 4/29/24

Question 1

What are the unifying characteristics of Diptera?

Answer 1

-one pair of functional wings
-one pair of halteres used for balance
-complete metamorphosis
-most lay eggs

Question 2

What is viviparous reproduction?

Answer 2

deposition of larvae

Question 3

Which flies are capable of serving as disease vectors?

Answer 3

-horse/deer flies
-mosquitoes
-sand flies
-tsetse flies
-face/horn flies
-biting midges

Question 4

What is myiasis?

Answer 4

invasion of living tissue by fly larvae, producing a pathological condition

Question 5

What is facultative myiasis?

Answer 5

fly larvae usually eat dead meat, but may become parasitic

Question 6

What is obligatory myiasis?

Answer 6

fly larvae cannot develop outside of host; require living flesh

Question 7

How do male and female mosquitoes differ?

Answer 7

-males feed on nectar and are pollinators
-females feed on blood

Question 8

Why must all stages of mosquito development stay on the water surface or on land?

Answer 8

they are dependent on oxygen

Question 9

What is the life cycle of mosquitoes?

Answer 9

-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

Question 10

Which three mosquito genera are of importance?

Answer 10

-Anopheles
-Aedes
-Culex

Question 11

What are the characteristics of Anopheles spp. mosquitoes?

Answer 11

-single eggs with floats
-angled hind end

Question 12

What are the characteristics of Aedes spp. mosquitoes?

Answer 12

-single eggs on “dry” surface
-horizontal hind end

Question 13

What are the characteristics of Culex spp. mosquitoes?

Answer 13

-floating egg raft
-horizontal hind end

Question 14

Which diseases can be spread by Aedes spp. mosquitoes?

Answer 14

-yellow fever
-dengue
-chikungunya
-zika
-heartworm
-eastern equine encephalitis

Question 15

Where do Aedes spp. tend to breed?

Answer 15

small areas of water, such as in tree holes or tires

Question 16

Which diseases can be spread by Culex spp. mosquitoes?

Answer 16

-west nile
-St. Louis encephalitis virus
-avian malaria
-heartworm
-western equine encephalitis

Question 17

Which diseases can be spread by Anopheles spp. mosquitoes?

Answer 17

-malaria
-heartworm
-eastern equine encephalitis

Question 18

What are the characteristics of Nematocera Simuliidae/black flies?

Answer 18

-small, stout bodied flies with short mouthparts
-black/gray/yellow brown
-breed in running water
-females require blood meal for egg maturation

Question 19

What does it mean for Simuliidae to have exerate pupa?

Answer 19

the appendages are free and sometimes mobile

Question 20

Which parasites are vectored by Simuliidae?

Answer 20

-Onchocerca spp.
-Dirofilaria ursi
-Leucocytozoon
-Trypanosoma

Question 21

What are the characteristics of Nematocera Ceratopogonidae/biting midges?

Answer 21

-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

Question 22

Which diseases are vectored by biting midges?

Answer 22

-bluetongue
-African horse sickness
-epizootic hemorrhagic disease
-Onchocerca spp.

Question 23

What are the characteristics of Brachycera Tabanidae/horse flies?

Answer 23

-“Aquatic,” found in muddy/marshy areas
-females require blood meal for egg maturation
-larvae may overwinter and pupate in spring

Question 24

What are the characteristics of Tabanidae/horse fly pathogenesis?

Answer 24

-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

Question 25

What are the characteristics of Cyclorrhapha?

Answer 25

-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

Question 26

What are the characteristics of Cyclorrhapha Gasterophilidae?

Answer 26

-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

Question 27

What are the two species of Gaterophilidae?

Answer 27

-G. nasalis: in intestines
-G. intestinalis: in stomach

Question 28

What are the two species of Cyclorrhapha Hypodermatidae?

Answer 28

-Hypoderma bovis: along spinal cord
-Hypoderma lineatum: along esophagus

Question 29

What are the characteristics of Hypodermatidae?

Answer 29

-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

Question 30

What are the characteristics of Hypodermatidae treatment?

Answer 30

-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

Question 31

What are the characteristics of Cuterebra spp.?

Answer 31

-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

Question 32

What are the characteristics of Musca autumnalis/face flies?

Answer 32

-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

Question 33

Which species/diseases are vectored by Musca autumnalis/face flies?

Answer 33

biologic vector: Thelazia spp.
mechanical vector: infectious bovine keratoconjunctivitis

Question 34

What are the characteristics of Haematobia irritans/horn flies?

Answer 34

-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

Question 35

What are the characteristics of Stomoxys calcitrans/stable flies?

Answer 35

-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

Question 36

What are the characteristics of C. hominivorax/screw worm?

Answer 36

-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

Question 37

What are the characteristics of Hippoboscidae?

Answer 37

-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

Question 38

What are the characteristics of Melophagus ovinus/sheep ked?

Answer 38

-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