Ten-lined Giant Chafer (Polyphylla decimlineata)

These two pictures probably represent different species, as there are many similar species in the United States.  The top picture is of a specimen collected in Arizona.  The bottom specimen was collected in Portland, Oregon.  Males can fan out their antennae (see bottom pic.).  This increases the surface area for detecting pheromones released by the females.  One very interesting characteristic of these beetles is the squeaky/buzzing noise they make when they are handled.  Females will drop ova in the bottom of a plastic deli-cup, whereas most beetles require substrate to lay ova in.  Of course, it is very preferable to offer them a dirt substrate, which will also help to prevent the ova from drying out.