Insects 2

Question 1

Tabanus

• Common name
• hosts

Answer 1

• horse fly

- large domestic or wild animals, humans, small mammals, birds

Question 2

Tabanus

-Identification

Answer 2

• stout bodied fly

- mouthparts slashing and sponging

Question 3

Tabanus

• Pathogenesis and lesions
• CS

Answer 3

• painful bites
• efficient mechanical vectors of several dz
• annoyance

Question 4

Chrysops

-Common name

Answer 4

deer fly

Question 5

Chrysops

-Identification

Answer 5

• dark bands across wings
• antennae elongate
• Bite horses in shaded areas
• horses will stand in the sun to avoid

Question 6

Tabanids

• Dx
• Tx and prevention

Answer 6

• identify fly
• Chrysops prefer shade
• Control in housing and on animals (repellents, insecticides)

Question 7

Melophagus ovinus

• Host
• Identification
• site of infection

Answer 7

• sheep
• flattened, hairy wingless dipteran
• blood sucking mouthparts
• wool

Question 8

Melophagus ovinus

-LC

Answer 8

• Female produces one egg which hatches inside her body
• Third instar adheres to fleece. Immobile instars pupate and visible on fleece
• adults emerge in 3 weeks in summer, longer in winter

Question 9

Myiasis

• Facultative
• Obligatory

Answer 9

• infestation of living animals w/ larvae of dipteran flies
• optional
• can not survive w/o host

Question 10

Cutaneous myiasis

Answer 10

“fly strike”

• maggots causing fly strike belong to Calliphoridae or Sarcophagidae Family
• Calliphoridae, the blow flies, screwworm
• sarcophagidae are the flesh flies

Question 11

Family Oestridae

• Adults
• Larvae

Answer 11

• long hairy flies, non functional mouthparts, short-lived

- obligatory parasites, host specific

Question 12

Cuterebra

• Common name
• hosts

Answer 12

• rodent or rabbit bot fly

- rodents, rabbits, zoonotic

Question 13

Cuterebra

-identification

Answer 13

third stage instar and season

Question 14

Cuterebra

-sites of infestation

Answer 14

subcutaneous connective tissue, can locate in nasal and oral regions and migrate to the brain

Question 15

Cuterebra

-Pathogenesis and lesions

Answer 15

fibrotic cyst forms from instar in subcutaneous tissue. Instar in brain of cat can lead to infarction

Question 16

Cuterebra

-CS

Answer 16

-lump in neck, fur constantly wet, hole drips fluid

Question 17

Cuterebra

-Dx

Answer 17

• Instar can be removed whole
• Type 1 hypersensitivity type rxn
• Wound heal slowly

Question 18

Cuterebra

-Tx and prevention

Answer 18

-several remedies may protect, but are not approved

Question 19

Hypoderma

• Common name-adults:
• Common name-instar:
• Hosts
• identification

Answer 19

• warble fly, heel fly, ox warble
• cattle grub
• cattle
• typical oestrid

Question 20

Hypoderma
LC
-H. lineatum
-H. bovis

Answer 20

• overwinter as 1st instar
• lineatum; accumulate in submucosa of esophagus. Laid in lines of 6 or more on lower limb, active begining of summer.
• bovis; accumulate in epidural fat of spinal cord, eggs laid singly, active later

Question 21

Hypoderma

-site of infestation

Answer 21

3rd stage instars found in lumps (warbles) on backs of cattle in spring

Question 22

Hypoderma

-pathogenesis and lesions

Answer 22

• 3rd stage larvae under skin causes damage and downgrade carcass; ECONOMIC LOSS
• lineatum death-> bloat
• bovis toxins -> paraplegia

Question 23

Hypoderma
CS
Dx
Tx

Answer 23

• faulty regurgitation, bloat, paraplegia
• identification of parasite
• MCLs kill early stages, timing

Question 24

Oestrus ovis

• common name
• host

Answer 24

sheep nasal bot, warble fly of sheep

-sheep, goats, llamas, humans

Question 25

Oestrus ovis | -identification

Answer 25

nasal bots 3 cm long, yellowish-white

Question 26

Oestrus ovis | LC

Answer 26

- female deposits 1st stage instars into nostril of sheep during flight - overwinter stage (2w-9m) - developing bots feed on mucus, cause irritation - in frontal sinuses develop to 2nd and 3rd stage instars - reach 3rd instar stage (3w-months) before sneezed out to pupate (4-7w) - Adults emerge, females survive 2w, depositing 500 instars

Question 27

Oestrus ovis - pathogenesis and lesions - CS

Answer 27

- instars irritate w/ hooks and spines and excessive secretion - bacterial infection common - to avoid attacks animals expend much energy and lose condition and weight - Aberrant migration through soft pallet may enter brain cavity - humans can become infected in the eye or lip, but does not develop further

Question 28

Oestrus ovis - Dx - Tx & prevention

Answer 28

- fly identification | - MCLs at beginning of summer and again midwinter

Question 29

Gasterophilus - common name - host - G. intestinalis - G. nasalis

Answer 29

- Bot fly larvae, bot fly - Horse - differentiate based on color and spines

Question 30

Gasterophiluis | -LC

Answer 30

- Egg hatches to 1st stage instar - G. intestinalis: hatches when licked; attached to tongue/lips - G. nasalis: hatches spontaneously; crawls into mouth - In oral cavity 1st to 2nd stage instar - Swallowed; develop 3rd stage instar (site specific); live up to 12 m - spring pass in feces, pupate - 3-9 wk adult fly

Question 31

Gasterophiluis intestinalis

Answer 31

- eggs on forelegs and shoulder - 3rd stage instars in non-glandular part of stomach and cardiac region - red in fresh feces - 2 rows of spines

Question 32

Gasterophilus nasalis

Answer 32

- eggs on intermandibular spaces - 3rd stage instars attach around pylorus and duodenum - yellow in fresh feces - 1 row of spines

Question 33

Gasterophilus - pathogenesis and lesions - CS

Answer 33

- adult fly is annoying - attached instars can provoke an inflammatory rxn - Fly worry

Question 34

Gasterophilus - Dx - Tx and prevention

Answer 34

- differentiate based on color, spines and location in host - seen during gastroscopy - manual removal of eggs - endoparasiticides for instar stages