SURVEY OF THE PARASITOIDS OF THE TULIPTREE APHID, ILLINOIA-LIRIODENDRI (HOM, APHIDIDAE), IN NORTHERN CALIFORNIA

A survey of the parasitoids of Illinoia liriodendri (Monell) in northe rn California conducted from 1988-1990 revealed the presence of 12 pri mary and 14 hyperparasitoid species. The most common primary parasitoi d was Aphidius polygonaphis (Fitch), which was imported from the easte rn United States in the 1970's and is now established throughout the a rea. New host records were noted for A. ervi Haliday, A. avenaphis (Fi tch), Praon occidentale Baker, P. unicum Smith, Diaeretiella rapae M'I ntosh, Lysiphlebus testaceipes (Cresson), and Monoctonus nervosus (Hal iday) (all Hymenoptera: Braconidae: Aphidiinae), and Aphelinus sp. nr. asychis Walker (Hymenoptera: Aphelinidae). The most common hyperparas itoid species were Pachyneuron aphidis (Bouche) and Asaphes californic us Girault (both Hymenoptera: Pteromalidae). New hyperparasitoid host records were noted for Pachyneuron californicum Girault on Aphidiine a nd Aphelinidae spp. and Coruna clavata Walker (Hymenoptera: Pteromalid ae) on Aphelinus sp.