I mostly shoot moths indoors at my desk. Here's a rundown of the gear I use to do it. As photography gear goes, this setup is relatively inexpensive. You could probably get decent photos with a good smartphone and forego the camera & lens.

moth photography setup

Gear

Lights

2x VILTROX VL-162T (can get by with 1x)

Approx 40 USD each on Amazon

Battery life is not great

Goosenecks

1 Smatree Adjustable Jaws Flex Clamp Mount per light
Approx 20 USD each on Amazon

Camera

Canon EOS M100
MSRP: 599 USD
No longer available
Current equivalent: Canon EOS M200, 549 USD MSRP

Lens

Canon EF-M 28mm f/3.5 Macro IS STM
MSRP: 299 USD

Ruler

I would prefer a combo inches/cm, but I found a pack of these that are metric only, and they work well.

Backgrounds

Various paper & cloth fragments
You might want to use a consistent background if you're going for more scientific approach. I like them to have some variation for being displayed in my gallery.

The lights are handy because they are also convenient to use outside at mothing events or if you find a bug outside you don’t want to bring inside. Also the Macro Lite LED on the lens is handy for this purpose.