This is the first comprehensive field guide to the flower flies (also known as hover flies) of northeastern North America. Flower flies are, along with bees, our most important pollinators. Found in a varied range of habitats, from backyard gardens to aquatic ecosystems, these flies are often overlooked because many of their species mimic bees or wasps. Despite this, many species are distinctive and even subtly differentiated species can be accurately identified. This handy and informative guide teaches you how. With more than 3,000 color photographs and 400 maps, this guide covers all 416 species of flower flies that occur north of Tennessee and east of the Dakotas, including the high Arctic and Greenland. Each species account provides information on size, identification, abundance, and flight time, along with notes on behavior, classification, hybridization, habitats, larvae, and more. Summarizing the current scientific understanding of our flower fly fauna, this is an indispensable resource for anyone, amateur naturalist or scientist, interested in discovering the beauty of these insects. · 3000+ color photos (field and museum shots) · Multiple images per species, with arrows highlighting key field marks · Grayscale images showing the actual size of the insect · Range maps for each species · Information on size, identification features, abundance, flight times, and more