PAN-PACIFIC ENTOMOLOGIST 69(1): 18-32, (1993) LIFE HISTORY AND DESCRIPTION OF IMMATURE STAGES OF PROCECIDOCHARES STONE] BLANC & FOOTE ON VIGUIERA SPP. IN SOUTHERN CAbIFORNIA (DIPTERA: TEPHRITIDAE)

-Procecidochares stollei Blanc & Foote is a facultatively multivoltine, stenophagous, gall-forming fruit fly on Viguiera laciniata Gray and V. deltoidea Gray var. parishii (Greene) Vasey and Rose (Asteraceae) in southern California. The latter host record is new; other published host records are questioned. Eggs, first through third instar larvae, and puparia are described for the first time. Galls formed on both host plants are described. The severe drought in southern California during the last 5 years has reduced the densities of P. stonei on V. d. var. parishii. Fly reproduction was restricted to one generation per year on the few host plant individuals that thrived in favored sites where they received supplemental water (i.e., along drip lines of boulders and margins ofpaved roads). Adultbehaviors described inc!ude grooming, feeding, wing displays, courtship, copulation and oviposition. Females typically lay eggs in clusters of two or more in axillary buds. Larvae develop gregariously, mainly as two, but up to 13 per gall. Four species of hymenopterous parasitoids are reported, the most common of which was Eurytoma sp. (Eury­