LIFE-HISTORY AND DESCRIPTION OF IMMATURE STAGES OF VALENTIBULLA-CALIFORNICA (COQUILLETT) (DIPTERA, TEPHRITIDAE) ON CHRYSOTHAMNUS-NAUSEOSUS (PALLAS) BRITTON IN SOUTHERN CALIFORNIA

Valentibulla californica (Coquillett) is univoltine and nearly monophagous on Chrysothamnus nauseosus (Pallas) Britton (Asteraceae). The larvae develop in short, subsurface mines mostly formed basally in current season's branches, and are not easily detected on infested plants. They cause limited swellings, not readily detectable galls. The egg, second and third instar larva, and puparium are described and figured. The egg, described for the first time for this genus, is unique among nonfrugivorous, California tephritids studied to date because of its ellipsoidal-fusiform shape, acutely tapered posterior, and its prominent, anterior pedicel bearing aeropyles of two distinct diameters. The third instar characteristically is shagreened, i.e. only the integument of the gnathocephalon, the anterior third of the prothorax, and a small area surrounding the posterior spiracular plates are not covered by minute, dome-shaped verrucae. The puparium also maintains the shagreened surface. Premating, mating, and postmating behaviors are described; they are few, and similar to the closely related genus, Aciurina. Hymenopterous parasitoids of V. californica include three species of chalcidoids reared as primary, solitary, endoparasitoids from isolated puparia: Eupelmus sp. (Eupelmidae), Eurytoma sp. (Eurytomidae), and Halticoptera sp. (Pteromalidae).