Identification of Aedes campestris from New Mexico: with notes on the isolation of western equine encephalitis and other arboviruses.

The research involved a survey of arboviruses in mosquitoes and gnats conducted in New Mexico in 1985 following an outbreak of suspected arboviral disease among wild horses. The collected insects were tested for viruses, with mosquitoes primarily being Aedes campestris, Aedes dorsalis, and Culex tarsalis species. While no arboviruses were found in the gnats, the mosquitoes yielded 37 viral isolates, including western equine encephalitis and other types of viruses.

Study Design and Execution

• The research was set in motion as a response to a suspected outbreak of arboviral disease among wild horses at the White Sands Missile Range in southcentral New Mexico.
• During the survey conducted in August 1985, a total of 20,566 mosquitoes and 8,900 biting gnats were collected.
• The main types of mosquitoes collected were Aedes campestris (54.8%), Aedes dorsalis (30.4%), and Culex tarsalis (13.2%).
• The collected insects were then tested or assayed for the presence of different types of viruses.

Findings & Outcomes

• No arboviruses were identified in the collected biting gnats.
• The mosquitoes, on the other hand, yielded a total of 37 viral isolates, which included various types of viruses.
• Most prevalent among these isolates was the western equine encephalitis virus (18 isolates), followed by California serogroup (15 isolates).
• They also identified single isolates of Cache Valley and Hart Park viruses.
• In addition to these, there were 2 unidentified rhabdoviruses.
• The western equine encephalitis virus isolates were extracted from Aedes campestris, Culex tarsalis, and Aedes dorsalis pools.
• California serogroup viruses, including 2 subtypes, were obtained from Aedes campestris (both females and males) and Aedes dorsalis pools.
• Cache Valley and Hart Park viruses were isolated from Aedes dorsalis and Culex tarsalis pools respectively, while the unidentified rhabdoviruses were derived from Aedes campestris and Psorophora signipennis pools.