About the Eastern Flower Fly
Syrphus knabi (Shannon, 1916), the Eastern flower Fly, is an uncommon species of syrphid fly observed in the eastern United States and Canada. Syrphid flies are also known as Hover Flies or Flower Flies because the adults are frequently found hovering around flowers from which they feed on nectar and pollen. Adults are 7.2–12.9 mm (0.28–0.51 in) long. The larvae are predators of a variety of aphids in trees.
For terminology Speight key to genera and glossary Size Length. 7.2–12.9 mm (0.28–0.51 in) Head The male has bare eyes that are holoptic, meaning that the eyes are completely joined together. The frons is yellow and is yellow pollinose on the upper two-thirds with a pair of brown anterior spots on the lower one-third. It has a bluish green reflection, a black spot above each antenna, and fine, rather long black hairs that continue a short distance down between the antennae and eyes. In the female, the frons is black and sparsely pruinose on the upper one-quarter, otherwise mostly yellow, densely yellow pruinose, and commonly slightly darkened medially. The anterior part is narrowly shining yellow and has a pair of brown anterior spots. The width of the frons... Wikipedia →