Immature do not have developed wings. Assassin bugs jab their sharp mouth into other insects they have captured, and then suck out the juicy stuff inside. It's a bugs life.

Someone provided this information:
"It looks like Zelus luridus, a common species of Reduviidae (Assassin bug) that we have in Ontario. Another species, Zelus tetracanthus, also occurs in our area but can be separated by the presence of 4 spines on the hind margin of the pronotum (luridus has two, one at each posterior humeral angle). Image looks a bit odd just because the wings are out."