Developmental morphology of stem galls induced by Aulacidea hieracii (Hymenoptera: Cynipidae) on hawkweed and Diplolepis spinosa (Hymenoptera: Cynipidae) on rose

Aulacidea hieracii (Bouche) and Diplolepis spinosa (Ashmead) are distantly related cynipid gall wasps found near Sudbury, ON that induce predominantly spherical, multichambered, stem galls. A. hieracii, a member of the basal tribe 'Aylacini', induces galls in the pith of Hieracium umbellatum L. (Asteraceae), commonly known as narrow-leaved hawkweed. D. spinosa, a more derived cynipid of the tribe Rhoditini, induces galls in the cortex and procambium of Rosa blanda Ait. (Rosaceae), a common wild rose in Canada, and Rosa rugosa Thunb., an introduced domestic rose from Japan.; All phases in the development of these galls were examined including initiation, growth and maturation in order to compare and contrast the different strategies of these two gallers for gaining control and redirecting the development of their respective host plants, and to examine the differences in gall tissues and structures that result. It was hypothesized that the developmental morphology of the two galls differ and that the A. hieracii gall would be simple in comparison to that of D. spinosa. (Abstract shortened by UMI.)...