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

HORSE FLY - LARVAE

• Hatch out in 4-7 days and drop into the water or the mud
• 7-11 larval instars are seen
• They are 11 segmented, maggot like, cylindrical with pointed ends 
• The larvae are carnivorous and can even bite man
• They have a distinct chitinous head, 3 thoracic  and eight abdominal segments
• A retractible siphon tube is seen on the 8^th abdominal segment. An organ called the Graber’s organ is located on the penultimate segment and is known to have respiratory and sensory functions
• The 1-7 abdominal segments show the presence of fleshy projections on the ventral aspect which are referred to as the pseudopods
• Terminal abdominal segment has fleshy anal papillae