Key to species of genus Aradus Fabricius of Argentina

1. All antennal segments uniformly brown.................................... Aradus angustellus Blanchard (Fig 3 C)

1’. Not all antennal segments uniformly brown................................................................. 2

2. Only the antennal segment III light colored.................................... Aradus penningtoni Drake (Fig 4 B)

2’. More of one antennal segment light colored................................................................. 3

3. The antennal segment III and basal half of IV yellowish......................... Aradus brasiliensis Usinger (Fig 3 B)

3’. Antennal segment I, ¾ basal of segment II and ¼ basal of segment III dark; the remainder yellowish........................................................................................... Aradus mexicanus Usinger (Fig 4 A)