LIFE-HISTORY AND DESCRIPTIONS OF ADULTS AND IMMATURE STAGES OF ACIURINA-IDAHOENSIS STEYSKAL (DIPTERA, TEPHRITIDAE) ON CHRYSOTHAMNUS-VISCIDIFLORUS (HOOKER) NUTTALL IN SOUTHERN CALIFORNIA

Aciurina idahoensis Steyskal is a univoltine, monophagous fruit fly th at forms distinctive, leafy, axillary bud galls on Chrysothamnus visci diflorus (Hooker) Nuttall, its only known host plant, throughout the w estern United States. Documentation is provided for the first time for the genus Aciurina, and more importantly, for the family Tephritidae as a whole, that the wing patterns of the adults of this species are s trongly sexually dimorphic in southern California, but not dimorphic, or much less strongly or consistently so, in other parts of its range, e.g., in Idaho. The egg, first through third instars, and puparium of A. idahoensis are described, illustrated, and compared with other sou thern California Aciurina spp. The egg has a long pedicel with a knobl ike, anterior apex. The third instar is characterized by having only o ne row of verruciform sensilla circumscribing the prothorax and no abd ominal lateral spiracular sensilla. Aciurina idahoensis co-occurs with A. semilucida (Bates) on C. viscidiflorus at lower altitudes (<1800 m ) in southern California; whereas, this host plant is partitioned alti tudinally and shared by A. ferruginea (Doane) and A. michaeli Goeden a t higher altitudes (>2100 m).