We present the first larval host records for the sawflies Sterictiphora sericea (Norton) (Argidae) (Rosaceae: Amelanchier Medik.), Ametastegia aperta (Norton) (Tenthredinidae) (Primulaceae: Lysimachia borealis (Raf.) U. Manns & Anderb.), and Macrophya flavolineata (Norton) (Tenthredinidae) (Asteraceae: Doellingeria umbellata (Mill.) Nees). New records are presented for six other tenthredinids: Quercus rubra L. (Fagaceae) for Caliroa lobata MacGillivray and C. lorata MacGillivray; Populus deltoides Bartr. ex Marshall (Salicaceae) for Fenusella populifoliella (Townsend); Ostrya virginiana (Mill.) K. Koch (Betulaceae) for Nematus corylus Cresson; Quercus ilicifolia Koord. & Valeton ex Seemen for Profenusa lucifex (Ross); and Anemone acutiloba (DC.) G. Lawson and A. americana (DC.) H. Hara (Ranunculaceae) for Pseudodineura parva (Norton). Larvae are described and illustrated for all of the non-leafmining species. The ichneumonid parasitoids Lathrolestes sp. and Erromenus ungulatus Townes & Townes were reared from C. lobata and P. parva, respectively.