You definately want backlight for the tranlucency Will. If I wasnt hitting a brick wall getting flies this season, I had planned to buy a silver reflector just for that.
As for bringing out more colour.
The black BG is a function of an underexposed image, relative to the ambient light available and then the flash compensating fo teh subject.
Worded another way, with no flash it would be a black image.
I kow just how tough it is to get get enough light shooting this stuff but I would hazard a guess you need more exposure/less flash to bring out more of the colours. If you can try getting the exposure to less than 2 stops underexposed pre flash and leave the flash to compensate for the rest.
hope you dont mind the photo add but its the difference between.
this

and

The black bg can be striking but for saturation you’ll likely want more light hitting the sensor.