Studies of elemental composition as a biological marker in insects. V. The elemental composition of Rhopalosiphum padi (L.) (Hemiptera: Aphididae) from Prunus padus at different localities

Abstract

AbstractEnergy dispersive X-ray spectrometry was used to make quantitative determinations of the elemental composition of plasma-ashed apterous and alate individuals of Rhopalosiphum padi (L.). The aphids were collected as fundatrigenae at various localities in England and Scotland, mostly from their main overwintering host, Prunus padus, but at one site also from P. virginiana. Robust-means principal components analysis of the data confirmed that there were differences, unrelated to source, between the elemental composition of apterae and alatae, with lower concentrations of S, K and Cl in the alatae. There were, however, no clear separations of sources in either morph except between some extreme groups; it is possible that genetic uniformity limits variation in elemental composition and, therefore, the existence of detectable source-related chemoprints in R. padi. Elements that provided some discrimination were S, Cl, Ca, Zn and possibly Al, and, except for S, their mean concentrations were all less than 1% of weight of the sample examined; difficulties in detecting differences at these low concentrations may have prevented detection of source-related chemoprints in R. padi.