Ochlerotatus trivittatus

Ochlerotatus trivittatus is identified by its scutum which has a pair of submedian, pale-scaled stripes, separated by a dark strip in the middle.  The pale-scaled stripes do not reach the border of the scutum like those of the Ochlerotatus triseriatus.
 
 

Ochlerotatus trivittatus also has unbanded hindtarsi.
 
 

Notice the abdominal markings.  The ventral side of the abdomen in mostly white; the dorsal side mostly dark.  When they come together, they form almost triangular shapes on the sides of the abdomen.