NAVLE Nervous

Avian Air Sac Mites Study Guide

Air sac mites are obligate endoparasitic hematophagous arthropods that infest the respiratory tract of birds, causing respiratory acariasis or sternostomatosis.

Overview and Clinical Importance

Air sac mites are obligate endoparasitic hematophagous arthropods that infest the respiratory tract of birds, causing respiratory acariasis or sternostomatosis. These tiny arachnids colonize the trachea, syrinx, lungs, and air sacs, where they feed on blood and tissue. Air sac mite infestations are particularly devastating in Gouldian finches and canaries, representing a leading cause of morbidity and mortality.

Species Primary Hosts Location Significance
Sternostoma tracheacolum Gouldian finches, canaries, budgerigars Trachea, syrinx, lungs, air sacs Most pathogenic; #1 killer of Gouldians
Cytodites nudus Chickens, turkeys, pheasants, pigeons Air sacs, pneumatic bones, lungs Pneumonia, peritonitis; white spots
Ptilonyssus spp. House sparrows, wild passerines Nasal passages Usually subclinical in wild birds

Etiology and Classification

Air sac mites belong to family Rhinonyssidae, order Mesostigmata. Key species:

Mite Morphology

  • Size: Males 0.4 mm; females 0.5-0.7 mm long; 0.2-0.3 mm wide
  • Color: Clear to dark red depending on blood meal status
  • Legs: Four pairs (arachnid characteristic)
  • Feeding apparatus: Chelate-dentate chelicerae for blood feeding
Stage Location Key Features
Egg Lung parenchyma Hatch shortly after oviposition (ovoviviparous)
Larva Lung Molt without feeding
Protonymph Female: posterior air sacs; Male: lung First blood meal; feeds on pulmonary tissue
Adult Female Air sacs, syrinx, trachea Reproduce; move to lungs to lay eggs
Transmissible Stage Buccal/nasal cavity, head plumage, bill Non-gravid, non-gorged female accomplishes transmission

Life Cycle and Transmission

S. tracheacolum is ovoviviparous and completes its life cycle in approximately 6 days.

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