Corythucha marmorata (Marbled lace Bug)
The pattern seems right for Corythucha marmorata but the spots are black instead of the typical brown. Photos of Corythucha marmorata at Bug Guide show a range of variability in coloration although most are brown. On Shining Aster (Symphyotrichum firmum).
''Corythucha marmorata'', the chrysanthemum lace bug, is a species of lace bug in the family Tingidae. It is found in Central America and North America.