Myiasis

Question 0

Define the 3 groups of myiasis producing flies

Answer 0

Primary myiasis - specific myiasis producers, larvae only found in living tissues
Secondary myiasis - semi-specific myiasis producers, eggs usually laid on dead tissues or decaying plant matter, but sometimes deposit larvae on living host
Tertiary myiasis - accidental myiasis, usually don’t develop in flesh, but can survive

Question 1

What is a myiasis

Answer 1

A Dipteran that parasitizes as a larvae only, and not as an adult

Question 2

What is the common term for Sarcophagidae

Answer 2

Flesh flies

Question 3

General physical characteristics of sarcophagidids

Answer 3

About 2x as large as house fly, gray thorax with dark longitudinal stripes abdomen is checkered black and grey

Question 4

Scientific name for blow flies

Other common names for blow flies

Answer 4

Calliphoridae

Bluebottle and greenbottle

Question 5

Why are they called blow flies

Answer 5

Blow their larvae or eggs onto meat

Question 6

What are common hosts of calliphorid myiasis

Answer 6

Rabbit

Question 7

Scientific name for American screwworm

Answer 7

Cochliomyia hominvorax

Question 8

What type of myiasis does the American screwworm produce

Answer 8

Primary myiasis

Question 9

How are American screwworms controlled

Answer 9

X-radiation and release of sterile males

Question 10

Where do American screwworm larvae pupate

Answer 10

Soil

Question 11

What is the only known insect to eat the living flesh of warm-blooded animals

Answer 11

American screwworm

Question 12

What countries have screwworms been eradicated from

Answer 12

USA
Mexico
Panama
Libya

Question 13

What is the major cause of avian myiasis in North America

Answer 13

Blood sucking maggots of the genus Protocallifora

Question 14

What families of fly are involved in obligate myiasis. (Besides screwworms)
As a group, what is their common name

Answer 14

Oestridae
Hypodermatidae
Gasterophilidae
Cuterebridae

Bot flies

Question 15

Where can the host-specific site-specific parasites be found on their hosts (identify host and site)

Answer 15

Oestrus in nasal passages of sheep
Hypoderma in the dorsal subcutis of cattle
Gasteroplilus in the stomach of horses

Question 16

Which bots occasionally affect humans, and how

Answer 16

Oestra deposit larvae in the eyes of shepherd

Hypoderma and Cuterebra migrate subtaneously

Question 17

What is a distinct feature of adult bot flies

Answer 17

Have vestigial mouthparts and energy is deprived from that which was stored when the fly was a larva

Question 18

What time of day are Oestrus most active

Answer 18

During warm times of day, or intervals of sunshine

Question 19

Life history of Oestrus ovis

Answer 19

Larvae deposited I sheep nostril
Larvae crawl to mucosa of nasal passages (2wk). Halt development until warm weather
Migrate to frontal sinus where they mature to 3rd stage larvae

Question 20

What types of signs do Oestrus ovis cause in sheep

How do you treat it

Answer 20

None in mild infections
Sneezing nasal discharge and partial blockage of nasal passages in heavy infection
Tx with ivermectin

Question 21

Name some other nasal bots and their hosts

Answer 21

Rhinoestrus purpureus - horse
Cephalopina - camels
Cephenemyia - cervids

Question 22

Genus and species of gad fly or heel fly

Answer 22

Hypoderma bovis

Hypoderma lineatum

Question 23

What is a warble

Answer 23

Walnut sized lumps on the backs of cattle formed by Hypoderma in the subcutis

Question 24

Life history of Hypoderma

Answer 24

Females glue their eggs to hairs on the legs H. Lineatum present in winter, H. Bovis present in summer Eggs hatch and larvae burrow into skin - h.lineatum present in esophageal tissues 5 mo later - h.bovis present in spinal canal Larvae ultimately migrate to sub-q tissues of back: molt twice, and grow larger When fully developed, emerge and fall to ground to pupate

Question 25

Which genus is associate with migrating lumps in people

Answer 25

Hypoderma

Question 26

Where do different species of Gasterophilus deposit their eggs

Answer 26

G. Nasalis - hairs of intermandibular space G. Hemorrhoidalis - hairs that adjoin the lips G. Intestinalis - hairs of forelegs and shoulders

Question 27

Where do first stage Gasterophilus larvae occur

Answer 27

Tunnels in epithelium covering dorsal surface of Rostropovich 2/3 of tongue and in pockets between molar teeth (Second stage also in mouth in interdental pockets or base of tongue)

Question 28

Where specifically are 3rd stage Gasterophilus larvae usually found

Answer 28

``` First ampulla of duodenum in horse (nasalis) Or stomach (intestinalis) above the fluid level ```

Question 29

What are the preferred hosts of cuterebra species

Answer 29

Rabbits and rodents

Question 30

What specific site are Cuterebra found on within the host

Answer 30

Under the skin

Question 31

Do Cuterebra produce primary, secondary or tertiary myiasis

Answer 31

Primary

Question 32

Life history of Cuterebra

Answer 32

Eggs deposited near animal burrows Enter through natural body openings Migrate to subcutaneous tissues, where development to third stage occurs Larvae drop off host to pupate

Question 33

How often to cuterebrae lay eggs

Answer 33

Once a year in north (univoltine) | Active. Year-round in south

Question 34

Describe migration of cuterebra in the host

Answer 34

``` Enter natural opening Move to tracheal tissue Penetrate thoracic cavity Penetrate diaphragm Enter peritoneal cavity Enter sub-q tissue ``` Migrates around body 3-6 wks before making it to skin. Majority of growth occurs in sub-q

Question 35

What affect do Cuterebra have on cats

Answer 35

Can develop warbles | Disease from migrating maggots (respiratory signs, neuro disease)

Question 36

Genus species human bot fly

Answer 36

Dermatobia hominus

Question 37

When do the larvae become. Bots

Answer 37

Large maggot stage

Question 38

How are Dermatobia hominus eggs deposited

Answer 38

Eggs deposited on another fly's body with hopes of contacting host... If no other fly, vegetation

Question 39

What stimulates D hominus eggs to hatch

Answer 39

Heat from vertebrate host

Question 40

Why can you not simply pull out a Dermatobia hominid when you spot the anterior end sticking out of a boil-like lesion

Answer 40

Maggot has large spine on its body that make it almost impossible to pull out the maggot without killing it or rupturing it (if maggot dies, increased risk if secondary bacterial infection)

Question 41

Genus and species of the tumbu fly

Answer 41

Cordylobia anthropophaga

Question 42

Where are tombu fly eggs deposited and what are their typical hosts

Answer 42

Eggs deposited in soil | Typical host is rodent. Can infect dog and human

Question 43

What is one way that has been reported as a means for Cordylobia anthropophaga to acquire humans as a host

Answer 43

Hang clothes up to dry and do not iron them

Question 44

Genus and species of Congo floor maggot

Answer 44

Auchmeromyia senegalensis

Question 45

What is particularly unique about the Congo floor maggot

Answer 45

Does not penetrate the skin, instead fastens to the host to suck blood

Question 46

What are common hosts of Auchmeromyia senegalensis

Answer 46

Wart hogs and other large burrowing mammals in Africa

Question 47

What type if human habitations has Auchmeromyia become adapted to

Answer 47

Those with wooden floors