6.1 Dipteran Flies Flashcards
What are the following characteristics of INSECTS:
- body divisions (#)
- pairs of legs
- pairs of wings
- 3 body divisions
- 3 pairs of legs
- 2 pairs of wings (if they have)
Describe the basic life cycle of diptera; what type of metamorphosis is this
Egg -> L1 -> Ln -> Pupa -> Adult
Complex metamorphosis
Describe the antennae and mouthparts of the following suborders of Diptera:
1) Nematocera
2) Brachycera
3) Cyclorrhapha
1) Nematocera has piercing-sucking mouthparts and long segmented antennae
2) Brachycera has slicing mouthparts and stylate antennae
3) Cyclorrhapha have variable mouthparts and aristate antennae
What are some examples of Diptera - Nematocera
mosquitos, gnats, midges, blackflies
What can Nematoceran flies cause (3)
- worry
- anemia
- transmission of pathogens (biological vectors)
What are two examples of Diptera - Brachycera
horse flies and deer flies
What can Brachyceran flies cause
- worry
- painful bites
- transmit disease (mechanical vectors)
What are some examples of Diptera - Cyclorrhapha
house flies, stable flies, face flies, flesh flies, warble flies, bot flies
What type of mouthparts does the common housefly (Musca domestica) have
sponging-lapping (and remember it has an aristate antennae since its a Cyclorrhaphan Dipteran fly)
Where do house flies (Musca domestica) lay their eggs? Where do they pupate? What do maggots eat?
In undisturbed cattle feces or rotting organic material; in soil; organic debris
Why are house flies (Musca domestica) a problem
Significant mechanical vectors of pathogens; also annoying
What type of mouthparts does the face fly (Musca autumnalis) have
Sponging-lapping
Where does Musca autumnalis lay eggs? Where does it pupate? What do ADULTS feed on?
Undisturbed cattle feces; soil; eye, nose and mouth secretions
What is unique about the preferred environment of face flies (Musca autumnalis)
Adults live on horses and cows outdoors ONLY and only come into buildings to overwinter
Why are face flies a problem (3)
- annoying, cause worry
- mechanical vector for pathogens (Moraxella bovis)
- biological vector for eyeworms (Thelazia spp.)
What type of mouthparts do horn flies (Haemotobia irritans) have? What other suborder of Dipteran flies have the same type of mouthparts?
Piercing-sucking; Nematocera
What is the size of horn flies in comparison to house flies
1/2 size
What is unique about the environment of adult horn flies (Haemotobia irritans)
Live almost constantly on hosts both inside and outside (the exception being leaving the host to lay eggs)
Where does horn flies (Haemotobia irritans) lay eggs? Where does pupation occur? Where do pupae overwinter? Where do adults live?
Eggs laid in undisturbed cattle feces; pupation in soil; pupae overwinter in soil; adults live on the backs of cattle
What problems do horn flies (Haemotobia irritans) cause (4)
- worry, annoyance
- reduces milk production and weight gain
- blood loss
- biological vector of a filarial nematode (Stephanofilaria stilesi)
What type of mouthpart does stable flies (Stomoxys calcitrans) have
bayonet-shaped
Where does Stomoxys calcitrans (Stable fly) lay eggs? Where do maggots live? Where is pupation?
Eggs laid in decaying vegetation; maggots in damp straw; pupation in soil (overwinter in soil)
What is the significance of stable flies (Stomoxys calcitrans) (3)
- worry and annoyance
- reduced milk production and weight gain
- intermediate host for Habronema (nematode)
How can we control muscid flies (house flies, face flies, horn flies, stable flies) through the environment
1) Timely removal of manure
2) Removal of sites with rotting vegetation/wet decomposition
3) Proper draining to prevent standing water and muck
How can we control muscid flies through medication/treatment
Insecticides (OPs or botanicals)
What is unique about the appearance of Melophagus ovinus (Sheep keds) (3)
NO WINGS on the fly, flattened dorsoventrally, hairy and leathery
How does Melphagus ovinus get around having no wings (in terms of lifecycle)?
Adult females lay mature larvae that pupate immediately (spin cocoons right away)
What is the significance of Melohagus ovinus (Sheep keds) (3)
- blood loss
- irritation
- damage to the wool (rubbing, staining)
When are sheep keds typically an issue and why
Winter -> indoors, long wool, crowding of animals to facilitate transmission
What are some agents of myiasis
- sarcophagids (flesh flies)
- calliphorids (blow flies)
- bot flies
- warble flies
what is the relative size of flesh flies and blow flies in comparison to house flies
flesh flies and blow flies are larger than house flies
Where do sarcophagids (flesh flies) and calliphorids (blow flies) lay eggs? Where do larvae develop? Where does pupation occur?
Lay eggs on or near wounds, carcasses, soiled skin/wool; larvae develop in the same site; pupation occurs off of the host
What are some predisposing causes to fly strike/wool strike caused by sarcophagids and calliphorids
- open, putrefying wounds
- decaying wool from moisture, urine, uterine discharge, diarrhea, etc.
- diarrhea from intestinal parasitoses
What are some problems with sarcophagids and calliphorids (4)
- toxemia from decaying flesh
- invasion of normal tissues
- migration into underlying skin and mm
- sheep kick and bite at the area
How should you treat fly strike caused by sarcophagids and calliphorids
shear away the area, physically remove visible maggots, apply insecticides, antibiotics for secondary infections if necessary
What species are affected by the following types of flies:
- warble fly (grubs)
- nasal bot fly
- rodent and rabbit bot fly
- stomach bot fly
warble fly (grubs): cattle, rarely horses (Hypoderma spp.)
nasal bot fly: sheep
rodent and rabbit bot fly: small animals (Cuterebrae spp.)
stomach bot fly: horses (Gasterophilus spp.)
What are unique features of adult bot flies
adults do not feed; they are bee-like
What are the two types of warble flies (cattle grub)? Where do they overwinter?
Hypoderma bovis: in the spinal canal or epidural fat
Hypoderma lineatum: in esophageal connective tissue
Do hypoderma spp. aka cattle grub aka warble flies cause OBLIGATE or FACULTATIVE myiasis
obligate
Describe the life cycle of hypoderma spp. aka warble flies aka. cattle grub
eggs laid on legs of cattle -> larvae penetrate skin -> larvae migrate to their overwintering site by December -> larvae migrate to the back after about 3 months (Feb-April) -> larve produce subcutaneous cysts in the back called warble -> larvae mature and drop out of the wound -> pupation in the environment
what are some problems caused by hypoderma spp. aka cattle grub aka. warble flies
1) holes in the hide can reduce the value
2) cannot ride horses if they warble in the saddle area
3) reduced production due to energy expenditure in the fall from oviposition
how do the larvae of cuterebra spp. aka rodent and rabbit bots differ from hypoderma spp. aka cattle grub aka warble flies
the cuterebrae larvae have little spines
does cuterebae cause FACULTATIVE or OBLIGATE myiasis
obligate
what is the life cycle of Cuterebrae spp.
eggs are laid near burrow openings -> larvae enter the host through the mouth or nose -> larvae migrate to the skin and cut a breathing hole -> larva mature from the hole and drop to the ground when mature -> pupation on the ground -> overwintering as pupae -> adults mate and lay eggs the following year
what are some problems caused by cuterebrae spp.
cysts, rarely larvae enter the CNS
how do you treat cuterebae (4)
physically remove the bot; debride cyst contents; anti-inflammatory/anti-biotics; systemic treatment if severe
what type of stomach bots are most common?
Gasterophilus intestinalis
do Gasterophilus spp aka stomach bots cause FACULTATIVE or OBLIGATE myiasis
obligate
what is the life cycle of gasterophilus spp.
eggs laid on the legs -> oral migration -> larvae swallowed -> overwinter in stomach -> larvae pass out with the feces when mature
what are the problems caused by Gasterophilus spp.
usually asymptomatic but can cause stomach lesions, rarely perforations causing abscesses and peritonitis
what are the two types of lice? how do you tell them apart? what does each feed on? what is the relative motility of each? Where would you find each?
Anoplura (sucking) and Mallophaga (chewing); Anoplura has a narrow head relative to the rest of the body whereas Mallophaga is wide; Anoplura feed largely on blood whereas Mallophaga feed on skin, hair, feather secretions; Anoplura found in protected areas of the host whereas Mallophaga are motile so can be found in a variety of locations on the host, typically in the underarm
What is the pathogen transmitted by the following BIOLOGICAL vectors:
- Musca domestica:
- Musca autumnalis:
- Stomoxys calcitrans
- Haemotobia irritans
Musca domestica: stomach nematodes of horses (Habronema, Draschia megastoma)
Musca autumnalis: eyeworm (Thelazia)
Stable flies: stomach nematodes of horses (Habronema)
Haemotobia irritans: filarial nematode (Stephanofilaria stelesi)
