Cinara edulis (Wilson), C. terminalis (Gillette and Palmer), and C. wahtolca Hottes were all larger when feeding on Pinus monophylla Torr. & Frem. than when feeding on P. edulis Engelm. Almost all nonsetal morphometric characters were longer in aphids on the former of these pinyon pines. Although mouthpart characters also followed this pattern of size in C. edulis and C. wahtolca, rostrum length showed the opposite pattern in C. terminalis and was shorter when on P. monophylla. This reversal in size pattern suggests that mouthpart size can be independent of overall aphid size. Principal components analyses corroborate the univariate statistics and we discuss the contribution of various characters to the principal components. We compare environmental induction and environmental selection as explanations for the observed size differences and discuss the taxonomic implications of our results.
Favret, Colin and Voegtlin, David J.
"Host-based morphometric differentiation in three Cinara species (Insecta: Hemiptera: Aphididae) feeding on Pinus edulis and P. monophylla,"
Western North American Naturalist: Vol. 64
, Article 11.
Available at: http://scholarsarchive.byu.edu/wnan/vol64/iss3/11