There are a couple of very easy steps any digital photographer can take to enhance those prickly identification characteristics on many insects; especially in the larval and/or instar stages.
 Contrast and Brighten – ad a bit more ‘illumination’ and bit more ‘pop’ to the image to bring out the sometimes ‘hidden’ elements. Generally only a tiny amount is needed to make the difference between a squinting, “… not sure?” and a bona fide “… you betcha!”.
However, if the image is really under or over exposed, then – as we all know – that’s what the beauty of digital photographic capture’s immediate delete ‘n re-shoot is all about.
But again, sometimes even then nature does not give us the 2nd shot. So, getting it right the first time is still the best bet.
Just remember, with digital, that first time can be a lot closer to the edge of usable and still be brought into the light of useful imagery. And it doesn’t require you to be an expert photographic technician to learn to do this either.
 Shooting in RAW format provides a huge degree of latitude. If you’re off by 3 f-stops – over or under in film or in a digital JPEG, you’re out-of-luck. But in a digital RAW image, you can still recover – at least 90% of the time – a very usable image. It may not win any contest awards for clarity and quality, but it will be usable.
So, just imagine how powerful this digital tool can be when it’s used within the optimum recoverable parameters of 1.25 and 2 stops UP or DOWN.
Again, this, too is not outside the reach of the common knowledge photographer. A bit of practice and your images will garner more ‘Wows!’ than you would have imagined.
The image above is an animated GIF showing the difference between the original image – a very properly exposed image, shot by my friend (Flickrname: urtica; Realname: Jenn Forman Orth ©2010) .. and one slightly enhanced for optimizing the shoulder spines.
Also take note the rest of the insect’s more visible characteristics… without compromising the overall integrity of the photo for true-to-life identification