Infection by rhinoestrus spp. larvae in equids in southern Italy : A new myiasis for the old continent

Two hundred and twelve native horses, were examined in 2 slaughterhouses in the Apulia region from January to November 2003, and 120 native horses and two donkeys in one slaughterhouse in Sicily from January to October 2003. Thirteen of 212 and five of 120 horses examined from Apulia and Sicily, respectively, were infested by nasal bot fly larvae. Both donkeys examined were positive. Overall, 213 larvae (L1,12 and 13), were collected from the infected animals. Larvae (L3) were identified on the basis ofperitreme structures and arrangement of the spines on the dorsal surface of the third segment. Some L3 collected from Apulia and Sicily presented morphological characteristics of both Rhinoestrus usbekistanicus and Rhinoestrus purpureus. The presence of mixed features on the L3 of Rhinoestrus collected from the same animals may be explained by the existence of a single species of Rhinoestrus presenting different morphotypes or of two species of Rhinoestrus (R. usbekistanicus and R. purpureus,) which are both present in southern Italy.