Scanning electron microscopy of Oestrus ovis larvae (Diptera: Oestridae): skin armour and posterior spiracles.

The skin armour and posterior spiracles of L1, L2 and L3 of Oestrus ovis (Diptera: Oestridae) are described and documented photographically by a scanning electron microscope. The complex and variable morphology of the attack organs of larvae of different stages makes it easier to understand better their exceeding adaptability to the host. The SEM survey has also allowed an apparently unreported anatomic particular with a probable sensory function to be detected in L1.