Some new synonyms in Aphididae (Hemiptera: Sternorrhyncha) Author Victor Author Eastop, F. Author Blackman, Roger L. text Zootaxa 2005 1089 1 36 journal article 37165 10.5281/zenodo.273344 d10b9f81-9b43-4efb-a0ea-b57b6229ef1f 1175­5326 273344 Myzus persicae ssp. nicotianae Blackman new status Myzus nicotianae was distinguished from M. persicae because samples collected from many parts of the world on tobacco ( Nicotiana tabacum ) and in different years showed consistent differences in morphology and biology associated with this host ( Blackman 1987 ). Most of the samples analysed were from regions where populations are permanently parthenogenetic, but Margaritopoulos et al . (2000) found that holocyclic populations of tobacco aphids in Greece could also be discriminated morphometrically from those collected on other crops, and from peach away from tobacco­growing regions. It has been suggested ( Clements et al . 2000a ) that these morphological differences could be due to phenotypic plasticity associated with feeding on a particular host plant. However, it is clear that the differences are genetically­based, as all the samples analyzed by Margaritopoulos et al . were clones reared under controlled conditions on the same host plant; the clones originating from peach in tobacco­growing regions and conforming to the morphology of nicotianae had never fed on tobacco. Relative preference for tobacco by nicotianae has been demonstrated in the laboratory ( Margaritopoulos et al ., 2005 ; Troncoso et al ., 2005 ). Genetic isolation between nicotianae and persicae cannot be complete, as amplified esterase genes conferring resistance to insecticides are identical in the two forms ( Field et al . 1994 ). Absence of complete reproductive isolation, perhaps in conjunction with a very recent origin of nicotianae , may explain the failure to find consistent diagnostic genetic markers ( Margaritopoulos et al . 1998 , Fenton et al . 1998 , Clements et al . 2000a , b ), or the divergence of gene sequence that one might normally expect to find between separate taxa ( Clements et al . 2000a ). However, the degree of isolation must have been sufficient to preserve the integrity of the tobacco­adapted genome for at least 15–20 years, and it would be unwise to regard this form simply as synonymous with M. persicae , as suggested by Clements et al . (2000a , b ), as this would hide important information. The tobacco aphid conforms to the broader definition of the subspecies category advocated by Müller (1986) and Rakauskas (2004) , which aims to ensure that indexable names are available for intraspecific variants of economically important species. We therefore propose that the tobacco aphid should be called M. persicae ssp. nicotianae .