LIFE-HISTORY AND DESCRIPTION OF IMMATURE STAGES OF PROCECIDOCHARES-STONEI BLANC AND FOOTE ON VIGUIERA SPP IN SOUTHERN CALIFORNIA (DIPTERA, TEPHRITIDAE)

Procecidochares stonei 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 ho st records are questioned. Eggs, first through third instar larvae, an d 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 a nd margins of paved roads). Adult behaviors described include grooming , feeding, wing displays, courtship, copulation and oviposition. Femal es typically lay eggs in clusters of two or more in axillary buds. Lar vae develop gregariously, mainly as two, but up to 13 per gall. Four s pecies of hymenopterous parasitoids are reported, the most common of w hich was Eurytoma sp. (Eurytomidae).