A morphological study of the populations of uroleucon on picris and andryla (homoptera, aphidoidea)

P. 235-242Aphids identified as Uroleucon (U.) picridis (Fabricius) had ultimate rostral segments longer than 1.5 times the length of their hind tarsal segment II and were collected from the compositae genera Picris and Andryala . Fourteen characters were measured on 84 apterous viviparous females , and an analysis showed that Uroleucon (U.) picridis living on these two composites can be separated morphologically into two groups consistent with the differences in the host plant. However, until further biological information is obtained , these two groups can not be given separate taxonomic status .S