Talk about beer goggles. The bottles have the some of the features that the beetles find attractive. They're big, orange / brownish, and the dimple at the bottom of the bottle reflects light in the same way a female's wing covers would.
As a result of the un-'canny' resemblance, the males can't help but fall head over heels for the bottles and try to have sex with them. Obviously, they're unsuccessful, but being the troopers that they are, they try until the hot Australian sun kills them.