An Ecological, Molecular, and Biochemical Comparison of Aedes Triseriatus (Say), the Vector of LaCrosse Virus, With Its Sibling Species, Aedes Hendersoni Cockerell

Aedes triseriatus (Say) is the primary vector of LaCrosse virus (LAC virus) that causes encephalitis in humans and especially young children. Aedes hendersoni Cockerell, a sibling species of Ae. triseriatus, is generally unable to transmit the virus because of a salivary gland escape barrier. Because the cycle of LAC virus is dependent on the ecology of its vector, the ecological studies of my thesis monitored oviposition activity for two consecutive years in two locations in an endemic area and one location in a non-endemic area of LAC virus. All sites had peaks in oviposition activity in July, one month prior to the peak incidence time of LAC encephalitis. The molecular studies of my thesis examined the sequences of the spacer regions in the ribosomal DNA loci of the Triseriatus group and constructed a phylogeny, of multiple clones from each species. The monophyly of the clones from some Ae. triseriatus and Ae. hendersoni individuals was supported by bootstrap values, but some clones from Ae. hendersoni Illinois and Colorado individuals did not cluster with regard to individual or population. This indicated that similar sequences are found among individuals of a species, even in different geographical populations of a species. Because the salivary glands of a vector are important to pathogen transmission, the biochemical studies of my thesis identified the apyrase, an inhibitor of platelet aggregation, of Ae. triseriatus and Ae. hendersoni . Apyrase activity was characterized from both species, but no difference in activities was observed. Some differences in apyrase levels after a blood meal were detected between Ae. triseriatus and Aedes aegypti L. (Rockefeller strain). These differences may explain why LAC encephalitis cases occur sporadically. The ecological, molecular, and biochemical relationships of Ae. triseriatus and Ae. hendersoni are an important factors in understanding the evolution of their infection with LAC virus and the barriers to the virus that have been described within the mosquitoes. By appreciating the importance that vector biology plays in the LAC cycle, we can identify risk factors for infection, improve the prediction of outbreaks of LAC encephalitis, optimize methods of mosquito control, and develop methods of interfering with the arbovirus cycle in mosquitoes.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Entomology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Reno, Hilary Elizabeth Lee

Contributors dc:contributor

• Novak, Robert J.

• Biology, Ecology

Language dc:language

eng

Identifier

(MiAaPQ)AAI9990122

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86486