Ecology of Aedes dorsalis (Diptera: Culicidae) in relation to western equine encephalomyelitis virus in the Coachella Valley of California.

The ecology of western equine encephalomyelitis virus (WEE) was studies during 1994-1996 along a portion of the north shore of the Salton Sea in Coachella Valley, California, known to support a focal Aedes dorsalis (Meigen) population. WEE was detected during 1995 by the seroconversion of sentinel chickens concurrently at sites within and outside of the area supporting Ae. dorsalis. WEE was not detected during 1994 or 1996; neither was WEE detected by seroconversion of sentinel rabbits nor by isolation from host-seeking females of either the primary vector, Culex tarsalis Coquillett (42,083 females tested in 913 pools), or Ae. dorsalis (10,804 females tested in 245 pools and 1,940 adults reared from field-collected immatures tested in 72 pools). Collectively, the results of this and previous investigations indicate that Ae. dorsalis may not be essential for the maintenance or amplification of WEE virus in southeastern California.