OBSERVATIONS ON HORSEFLIES INFECTED WITH LARVAE OF Elaeophora schneideri ^*

Emergence of the arterial worm Elaeophora schneideri in moose (Alces alces) and tabanid fly vectors in northeastern Minnesota, USA

“…Our surveillance of tabanid flies for the presence of filarioid nematodes further confirms the presence of E. schneideri in Minnesota and suggests the nematode is being transmitted and maintained in the environment. An overall prevalence of 5.8% in the Minnesota flies was relatively high compared to the 0.3% reported in South Carolina [ 41 ] and 0.8% in Montana [ 42 ]; however, prevalence rates as high as 20% have been reported in New Mexico [ 26 , 43 ]. Interestingly, we were able to sequence E. schneideri from Chrysops spp.…”

“…Historically, E. schneideri was thought to be primarily found in the western half of North America, presumably in conjunction with the geographical range of the well-adapted mule deer and black-tailed deer definitive hosts. In these hosts, prevalence of E. schneideri is high, reaching levels of 78–100% [ 26 , 32 ]. However, the parasite has also been reported in white-tailed deer in Florida, Georgia, South Carolina and Texas with a much lower prevalence of 2–10% [ 24 , 40 ].…”

“…The life-cycle of E. schneideri involves a cervid host and a hematophagous insect vector. Mule deer ( Odocoileus hemionus ) and black-tailed deer ( Odocoileus hemionus columbianus ) are definitive hosts [ 22 – 25 ], and transmission occurs via the bite of a tabanid horse fly or deer fly (Diptera: Tabanidae) [ 26 , 27 ]. Tabanid flies become infected when they ingest microfilariae (L1) in a blood meal.…”

Temporal Occurrence of Third-Stage Larvae of Elaeophora Schneideri in Tabanus Lineola Hinellus on South Island, South Carolina

“…It was selected as the study site because white-tailed deer (Odocotleus otrgtnianus) infected with E . schnetderi have been found on the South Island portion of the area (Hibler and Prestwood, 1981) and also because potential intermediate hosts were abundant. This study was conducted on a 4&ha hammock on the northern section of South Island.…”

Elaeophora in the meninges of a Malayan sambar (Rusa unicolor equina)

“…The 18S rDNA sequences and the presence of microfilariae identify this nematode as the filaroid E. schneideri , which is endemic to western North America, including California, where the well-adapted definitive hosts, mule deer and black-tailed deer, reside. Previous studies examining the prevalence of E. schneideri in California found 4–44% of mule deer 10 and 78% of black-tailed deer 20 harbored E. schneideri . Also, nematodes consistent with E. schneideri have been observed in the carotid arteries of native mule deer in southern California examined at the Wildlife Disease Laboratories in San Diego (unpublished observation).…”