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Myiasis Producing Flies (view source)
Revision as of 20:20, 5 November 2008
, 20:20, 5 November 2008→''Oestrus ovis''
*Also known as the sheep nasal bot fly
*Also known as the sheep nasal bot fly
*Larvae parasitise the nasal chambers of sheep and goats
*Found in most sheep rearing areas of the world
'''Recognition'''
'''Recognition'''
*13-15mm long
*Grey colouring
*Black spots on abdomen
*Clear wings
*Larvae have distinct black bands on each body segment
'''Life Cycle'''
'''Life Cycle'''
*Larvae are squirted into the nostils of sheep in a jet of liquid
*The larvae crawl caudally into the nasal cavity and feed on the nasal mucosa and mature before returning to the nostrils
*Larval development takes up to two months
**Larvae can overwinter in the nasal cavity if deposited late in the summer
*Once the larvae have developed they are sneezed out and pupate on the ground
*The adult fly emerges one months later
*Adult flies only live for 2-3 weeks
'''Pathogenesis'''
'''Pathogenesis'''
*Adult flies can annoyance
**Interrupts feeding
**Leads to a decreased weight gain
*Larvae cause nasal irritation, nasal discharge and sneezing
**Irritate the nasal mucosa with oral hooks and spines causing a viscous exudate to be produced from which they feed
**Heavy infestations lead to erosion of the bones in the sinuses (turbinate bones)
**Penetration of the brain leads to '''false gid''' (high stepping gait and incoordination)
*[[Respiratory Parasitic Infections - Pathology#Oestrus ovis|Apthology in the nasal cavity]]
*[[Respiratory Parasitic Infections - Pathology#Oestrus ovis|Apthology in the nasal cavity]]
'''Control'''
'''Control'''
*Systemic [[Ectoparasiticides|insecticides]] can be used in heavy infestations
*In warmer countries, strategic prophylactic treatment can be used
===''Gasterophilus'' spp.===
===''Gasterophilus'' spp.===