Whitney Cranshaw, Colorado State University, Bugwood.org
Jeff Hahn, University of Minnesota Extension
Size: 1/4 - 1 1/4 inch long
Description: Soft-bodied insects with clear, triangular-shaped wings; slender abdomen with 2-3 long filaments (cerci) at the end of it.
Where/When: Associated with water and nearby areas, attracted to lights and can be found around buildings, often in large numbers; present May into September.
Significance: They can be a nuisance when they occur in large numbers. They do not harm people or property.