My reference was indeed a real beetle; a preserved one from a museum, to be exact. (They had loads of different ones, from big armour-plated beasties like this fellow to tiny, brightly-coloured little critters that looked like shiny gems.) And I quite agree, it's a shame more people don't try their hand at doodling insects, because they make jolly interesting subjects. You probably wouldn't want them running about on your drawing desk, though.