Thick-legged hoverfly 
Toxomerus boscii 
Transverse Flower Fly 
Trivittate Marsh Fly 
Variable Aphideater 
Variable Duskyface Fly 
Volucella bombylans 
Volucella inanis 
Volucella zonaria, 
Wasp mimicking syrphid fly 
Western Calligrapher 
Western Hornet Fly 
Western Pond Fly 
Western Wood Fly 
White-bowed smoothwing 
Xanthogramma dives 
Xylota flavitarsis 
Xylota segnis 
Yellow-barred Peat Hover Fly 
Yellow-haired Sun Fly 
Yellow-shouldered Stout Hover Fly 
Yellowjacket hover fly