VPA 221: Veterinary Entomology and Acarology (1+1)

Psoroptes ovis

MORPHOLOGY - PSOROPTES OVIS

• Cause of Sheep scab – an important disease
• Australia – eradicated
• Britain – 20 years back eradicated, it has now re-entered
• U.S.A – Still exists in certain states

Morphology

• Male
  •  A pair of copulatory suckers in ventral side
  • A pair of large terminal tubercles bearing several hairs
• Female
  • Possess suckers with jointed pedicels on 1^st, 2^nd and 4^th pair of legs
  • PUBESCENT female also provided with a pair of posterior copulatory tubercles which are absent in ovigerous females
  • Ovigerous female will have a genital aperture on the anterior aspect of ventral side