Flies Flashcards
• What are flies of veterinary importance?
Direct effects – bites, irritation, anaemia, hypersensitivity & Myiasis causing flies & indirect effects – vectors of disease
• What are the two suborders of flies?
Brachycera & Nematocera (blood feeders)
• What are the four main types of Nematocera?
Simuliidae (black flies), Culicidae (mosquitoes), Ceratopogonidae (biting midges) & Psychodidae (sand flies)
• What is significant about a mosquito’s life cycle?
Require still water
• What is a biological vector?
When the organism carries out a developmental cycle or multiplies within the vector e.g. Dirofilaria immitis – first stage larvae acquired by mosquitoes through feeding, development of the microfilariae to the infective third stage occurs within the mosquito, infective larvae move into the bite wound and migrate through the tissues to the heart
• Categorise the Brachycera depending on if the larvae cause problems of if the adult blood meal does?
Larvae cause problems – Oestridae, Sarcophagidae, Calliphoridae, some Muscidae – house flies, head flies
Adult blood meal causes problems – Tabanidae, Hippoboscidae, Glossinidae, some Muscidae – stable flies, horn flies
• What are Tabanidae?
Horseflies, deer flies and clegs
• What are Hippoboscidae?
Obligate blood-feeding ectoparasites, with both males and females feeding on blood, adenotrophic viviparity
• What does adenotrophic viviparity mean?
A single egg hatches inside the female and the larva is retained until it is ready to pupate
• What is Melophagus ovinus?
A member of the family Hippoboscidae, the sheep ked – wingless fly
• What are some of the common features of Glossinidae?
Tsetse flies – reproduce via adenotrophic viviparity, vectors of the parasitic protozoan which causes trypanosomiasis
• List the obligate and facultative myiasis flies?
Obligate – Sarcophagidae (flesh flies) & Oestridae (bot flies)
Facultative – Calliphoridae (blow/bottle flies) & some Muscidae (house flies – Musca domestica)
• What are the three genus of the family Oestridae of particular veterinary importance?
Gasterophilus – horse botfly
Oestrus – sheep nasal botfly
Hypoderma – heel flies, warble flies, cattle grubs
• What are the three significant species of the genus Gasterophilus?
A Gasterophilus intestinalis, female lays eggs around the knees
Gasterophilus nasalis, females lay eggs under the jaw
Gasterophilus haemorrhoidalis, female lays eggs around the lips
• What are the effects of the genus Oestrus?
Cause a profuse discharge and thickening of the nasal mucosa that impairs respiration, larvae present in the sinuses are sometimes unable to escape; they die and lead to septic sinusitis
• What is the most common problem of Calliphoridae?
Flystrike – blow/bottle flies are the primary cause e.g. Lucilia sericata
• Lucilia sericata is anautogenous, what does this mean?
They must acquire a protein meal before maturing their eggs
• What are flesh flies (Sarcophagidae)?
An obligate larval parasite of warm blooded vertebrates that causes rapid and severe myiasis in most livestock particularly sheep – not present in the UK
• What is Hydrotaea irritans?
Sheep head fly – feed on secretions from the eyes, nose and debris at horn base, feeding causes irritation and scratching resulting in wounds
• What is Haematobia irritans?
Horn fly – takes blood meal (most often from cattle), causes painful bites, one of the most economically important pests of cattle worldwide
• How can flies be controlled?
Chemical control applied to animal and/or the environment, husbandry/management, barriers, trapping, biological control
• What are behavioural responses?
The stress caused by flies can result in a failure to graze normally, resulting in decreased milk production and reduced weight gains, further losses can occur when animals injure themselves in their efforts to escape the flies – gadding, bunching
• What is flystrike?
A type of myiasis caused by flies which lay eggs into wounds, orifices or rotten fleeces
• Unless the process is halted what might happen to the animal?
The infested animal may die from shock, histolysis or infection
