Role of Horse Fly (Tabanus fuscicostatus Hine) and Stable Fly Stomoxys calcitransL.) in Transmission of Equine Infectious Anemia to Ponies in Louisiana

Abstract

SUMMARY Studies were conducted on the possible role of the Horse fly ( Tabanus fuscicostatus Hine) and the stable fly ( Stomoxys calcitrans L.) in the mechanical and biological transmission of equine infectious anemia ( eia ; Swamp fever) to Shetland ponies in Louisiana. Using T. fuscicostatus, all mechanical transmission attempts from acutely infected ponies were successful, even with as few as 10 fly bites; however, all mechanical transmission attempts from a chronically infected pony and biological transmission attempts from acutely infected ponies were unsuccessful. Neither mechanical nor biological transmission attempts with S. calcitrans was successful. Field observations indicated a small population of stable flies existed in an area having a record of high prevalence of eia , whereas a relatively large population of horse flies was present in the same area.