Hi Ed,
My first post here. I have processed images similar to yours, albeit with cells using a technique called interference reflection rather than with insects. My challenge was to increase the perceived contrast within the cells. My approach then (in 2008) was to apply a 3x3 low pass filter with a 41x41 high pass filter. This generated good contrast, removed uneven illumination and removed the dark space due to the aperture. You do, however, generate a thin line along the edge of that space. I'm away from Mathematica atm, but I reckon you should get some mileage from the LaplacianGaussianFilter. You are effectively generating a bandpass filter and the size of the low and high pass kernels define the band pass.

HTH,

Mark

Arnoud,

Thanks so much !
Your solution is as effective as it is short and clear.
I am glad that I asked.

Have a great day.

Ed

Hi Ed,
Arnoud's solution is a nice trick I wasn't aware of and whilst I didn't think my answer would be exactly what you were looking for I'm fairly certain you'll be stunned at the level of detail in your image that can be extracted using my suggestion. You might want to combine both approaches in order to remove the artefact that mine generates.

All the best and good luck!

Mark