If you can't locate buckeye eggs or caterpillars; another option is to take a butterfly net and to try and catch a female buckeye.  Then, place cuttings of plantain or snapdragon in a cage and place a live female buckeye inside to lay eggs.  Click here to watch a short video.  Another option is to observe a live female lay eggs and then collect the eggs.  Here is another video that demonstrates that.