Parhelophilus porcus
Parhelophilus porcus  (Walker, 1849), the black bog fly, is an uncommon species of syrphid fly observed in Northern North America. Hoverflies can remain nearly motionless in flight. The adults are also known as flower flies for they are commonly found on flowers from which they get both energy-giving nectar and protein-rich pollen. The larvae are the long tailed "rat-tailed" type. References

Diptera of North America
Eristalini
Insects described in 1849
Taxa named by Francis Walker (entomologist)
Hoverflies of North America