Changes

*Western EEV: ''Culex tarsalis''

*Western EEV: ''Culex tarsalis''

*Venezuelan EEV: ''Culex melanconium'', ''Aedes'' spp., ''Phosphora'' spp.

*Venezuelan EEV: ''Culex melanconium'', ''Aedes'' spp., ''Phosphora'' spp.

''Culiseta melanura'' is a vector for EEE.  It is largely confined to freshwater swamps, feeds primarily on swamp birds and is rarely found in areas of increased horse density.  This mosquito generally serves as a vector for the enzootic cycle involving swamp birds.  ''Aedes'' spp. are more important in epizootics and epidemics.  Culex tarsalis is the primary vector that maintains WEE virus in an enzootic cycle with passerine birds.  Dermacentor andersoni ticks, Triatoma sanguisuga (assassin bug), and the cliff swallow bug (Oeciacus vicarius) may also be involved as vectors or overwintering reservoirs fro WEE.  Several species of mosquitoes from at least 11 geerna have been determined ot be naturally infected with epidemic strains of VEE virus.  Ticks may also be capable of viral trasnmission.

''Culiseta melanura'' is another vector for Eastern EEV.  It feeds mostly on swamp birds, completing an enzootic cycle of viral transmission.  ''C.melanura'' is thus an inhabitant of freshwater swamps and is not usually found in areas densely populated by equids.  ''Aedes'' spp. are more important in epizootics and epidemics.  Culex tarsalis is the primary vector that maintains WEE virus in an enzootic cycle with passerine birds.  Dermacentor andersoni ticks, Triatoma sanguisuga (assassin bug), and the cliff swallow bug (Oeciacus vicarius) may also be involved as vectors or overwintering reservoirs fro WEE.  Several species of mosquitoes from at least 11 geerna have been determined ot be naturally infected with epidemic strains of VEE virus.  Ticks may also be capable of viral trasnmission.

Vectors transmit viral particles between sylvatic hosts when takin ga blood meal.  If the virus can peentrate the gut of the vector, then it may pass throhg the haemolymph to the oral glands, multiply and subsequntrly be shed in the saliva and other oral secretions.  If th eblood meal octnains adequate numbers of viral particles, multiplication may not be rrequired for transmission.  It is likely tha the mosquito remians infected for life.

Vectors transmit viral particles between sylvatic hosts when takin ga blood meal.  If the virus can peentrate the gut of the vector, then it may pass throhg the haemolymph to the oral glands, multiply and subsequntrly be shed in the saliva and other oral secretions.  If th eblood meal octnains adequate numbers of viral particles, multiplication may not be rrequired for transmission.  It is likely tha the mosquito remians infected for life.