Studies on Species of the Aphid Genus Cinara on Pinus Edulis and Pinus Monophylla

Abstract

102 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003.Cinara are aphids (Hemiptera: Aphididae: Lachninae) that feed exclusively on conifers of the Cupressaceae and Pinaceae. They are speciose and particularly diverse in North America. Their phylogenetics is completely unknown and they historically have been treated based on the taxonomy of their hosts. They are also known to specialize on particular woody parts of their hosts (roots, branches, shoots, etc.). In Chapter 1, using cytochrome oxidase I DNA sequences, I performed molecular phylogenetic analysis of Cinara species feeding on pinyon pines and determined that switching hosts played a key role in the speciation of the genus. This was reflected in the fact that species sharing a common feeding site on different hosts were more closely related than those sharing the same host but at different feeding sites. This study also revealed that Cinara wahtocla Hottes represented two species on the two different pinyon pine species, Pinus edulis Englem. and P. monophylla Torr. & Frem. In Chapter 2, I compared the morphology of C. wahtolca, C. edulis (Wilson) and C. terminalis (Gillette and Palmer) feeding on the two pinyons. All three species were larger when on P. monophylla, but the rostrum of C. terminalis showed the reverse trend, being shorter when feeding on P. monophylla than when on P. edulis. The analysis of rostrum length showed that this particular character can be independent of aphid size. In Chapter 3, I used principal components analysis to determine the validity of several pinyon-feeding species. I concluded by synonymizing five species. Finally, in Chapter 4, I provided a new technique for extracting DNA from aphids which preserves the cuticle intact for slide-mounting. I presented this technique in the context of DNA taxonomy of aphids, a tool that should be developed and will prove to be very useful.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD