Forming within the old exoskeleton, which splits down the middle, the 17 mm long pupa will take about 17 days to mature, gradually changing from creamy white to reddish brown. "Cyclocephala borealis" males were found to mate freely with females of the species "Cyclocephala immaculata", which has morphologically indistinguishable larvae, in a laboratory. The resultant eggs appeared to develop normally; however, fully formed larvae never emerged from them. Northern masked chafers are considered a common pest of turf and cereal crops from New England to Illinois. Most damage to turf occurs in September and October and again in spring. This beetle is recognized as being edible to humans. "Cyclocephala borealis" was first described by Hermann Burmeister as "Cyclocephala villosa". As another species from Bolivia had already been given that name it was renamed "borealis" by Gilbert John Arrow.