Posted to verify genus & species and extend BugGuide map range for the sp. into CA if ID is correct.

Resource: Key to the genera of nearctic Syrphidae (1) and Arnett Beetles Vol 2 (2).

Characters that seem important --------
Head
-- Face with a distinct yellow tubercle.
-- Posterior margin of eye almost straight and without any deep emargination.
-- Antennae shorter than head and with dorsal arista.
Thorax
-- Striped pattern on back of thorax.
-- Single medial dark triangular marking on each wing.
-- Anterior anepisternum haired (hard to photograph).
-- Prosternum without hairs and hidden behind concave posterior head cavity (not shown).
-- Lower calypter without hairs, only soft microscopic pile (pic shows only empty dark space where hairs would be showing if they were there between the folds of upper and lower calypters).