Value of the extra pixils

Came across a ground beetle in an empty food storage box in the kitchen a couple of weeks ago - no idea how it had got there.  Using my carabid to genus key it came to genus Bradycellus.  I could see the shape of the mentum (a rectangular structure under the head forming a lower lip for the mouth-parts) with the microscope so I thought I'd try to photograph it.  I was disappointed with the result using my Canon EOS 40D with a MP-E 65 mm macro lens at full zoom - it didn't seem to resolve the detail or in particular show the tooth at the front edge of the mentum.  I knew the camera was 6 megapixils so wondered what increasing that would do.  So off to the camera shop and return with an 18 megapixil Canon EOS 100D and me oh my what a difference.

The image on the left shows the 6MP version and that on the right the 18MP one.  It is much clearer on my computer of course as the image has lost resolution dropping it here.  I can see the microscopic surface texture of the underside of the head and prosternum and the mentum (the structure between the base of the antennae) is much clearer including the tiny central tooth.  I've placed two other photos of the beetle in my Bradycellus key online.

To the mystery of how it ended up in a kitchen storage box.  The beetle keys to Bradycellus verbasci, a common species with over 1600 records on the National Biodiversity Network site including our grid square.  My notes say that it is attracted to light so it must have come inside during the late summer and accidentally got stuck in the cupboard.